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Sample records for site sediment application

  1. Conceptual Site Model for Newark Bay—Hydrodynamics and Sediment Transport

    Directory of Open Access Journals (Sweden)

    Parmeshwar L. Shrestha

    2014-02-01

    Full Text Available A conceptual site model (CSM has been developed for the Newark Bay Study Area (NBSA as part of the Remedial Investigation/Feasibility Study (RI/FS for this New Jersey site. The CSM is an evolving document that describes the influence of physical, chemical and biological processes on contaminant fate and transport. The CSM is initiated at the start of a project, updated during site activities, and used to inform sampling and remediation planning. This paper describes the hydrodynamic and sediment transport components of the CSM for the NBSA. Hydrodynamic processes are influenced by freshwater inflows, astronomical forcing through two tidal straits, meteorological conditions, and anthropogenic activities such as navigational dredging. Sediment dynamics are driven by hydrodynamics, waves, sediment loading from freshwater sources and the tidal straits, sediment size gradation, sediment bed properties, and particle-to-particle interactions. Cohesive sediment transport is governed by advection, dispersion, aggregation, settling, consolidation, and erosion. Noncohesive sediment transport is governed by advection, dispersion, settling, armoring, and transport in suspension and along the bed. The CSM will inform the development and application of a numerical model that accounts for all key variables to adequately describe the NBSA’s historical, current, and future physical conditions.

  2. Application of parasound data for sediment study on methane seep site at Simeulue basin

    International Nuclear Information System (INIS)

    Wiguna, Taufan; Ardhyastuti, Sri

    2015-01-01

    The Parasound data presents sea depth and sub-bottom profiler. In terms of geological terminology, parasound data represents significant recent surface sedimentary structures that valuable for the selection of subsequent sampling site such as sampling at methane seep site. Therefore, Parasound is used to detailing methane seep at surface sediment following seismic data interpretation. In this study, parasound is used to focus observe area especially for sediment study on methane seep site. The Parasound systems works both as narrow beam sounder use high frequency and as sediment echosounder use low frequency. Parasound acquisition applies parametric effect. It produces additional frequency by nonlinear acoustic interaction of finite amplitude waves. Parasound transducers have 128 elements on 1 m2 and need transmission power up to 70 kW. The results of this study are discovered large seep carbonate with porous surface which means there are gas expulsions passing through that rock

  3. A multicriteria-based methodology for site prioritisation in sediment management.

    Science.gov (United States)

    Alvarez-Guerra, Manuel; Viguri, Javier R; Voulvoulis, Nikolaos

    2009-08-01

    Decision-making for sediment management is a complex task that incorporates the selections of areas for remediation and the assessment of options for any mitigation required. The application of Multicriteria Analysis (MCA) to rank different areas, according to their need for sediment management, provides a great opportunity for prioritisation, a first step in an integrated methodology that finally aims to assess and select suitable alternatives for managing the identified priority sites. This paper develops a methodology that starts with the delimitation of management units within areas of study, followed by the application of MCA methods that allows ranking of these management units, according to their need for remediation. This proposed process considers not only scientific evidence on sediment quality, but also other relevant aspects such as social and economic criteria associated with such decisions. This methodology is illustrated with its application to the case study area of the Bay of Santander, in northern Spain, highlighting some of the implications of utilising different MCA methods in the process. It also uses site-specific data to assess the subjectivity in the decision-making process, mainly reflected through the assignment of the criteria weights and uncertainties in the criteria scores. Analysis of the sensitivity of the results to these factors is used as a way to assess the stability and robustness of the ranking as a first step of the sediment management decision-making process.

  4. Predicted effectiveness of in-situ activated carbon amendment for field sediment sites with variable site- and compound-specific characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yongju, E-mail: ychoi81@snu.ac.kr [Department of Civil and Environmental Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Cho, Yeo-Myoung; Luthy, Richard G. [Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020 (United States); Werner, David [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2016-01-15

    Highlights: • The model accounts for the heterogeneity of AC distribution in field applications. • AC amendment effectiveness is predicted for ten sediment sites. • An HOC mass transfer model and calibrated parameters provide reliable predictions. • AC amendment is predicted to be effective for most sites. • K{sub ow}, K{sub d}, and equilibrium-based calculations are useful indicators. - Abstract: A growing body of evidence shows that the effectiveness of in-situ activated carbon (AC) amendment to treat hydrophobic organic contaminants (HOCs) in sediments can be reliably predicted using a mass transfer modeling approach. This study analyzes available field data for characterizing AC-sediment distribution after mechanical mixing of AC into sediment. Those distributions are used to develop an HOC mass transfer model that accounts for plausible heterogeneities resulting from mixing of AC into sediment. The model is applied to ten field sites in the U.S. and Europe with 2–3 representative HOCs from each site using site- and HOC-specific model parameters collected from the literature. The model predicts that the AC amendment reduces the pore-water HOC concentrations by more than 95% fifteen years after AC deployment for 18 of the 25 total simulated cases when the AC is applied at doses of 1.5 times sediment total organic carbon content with an upper limit of 5 dry wt%. The predicted effectiveness shows negative correlation with the HOC octanol–water partitioning coefficients and the sediment-water distribution coefficients, and positive correlation with the effectiveness calculated based on equilibrium coefficients of sediment and AC, suggesting the possibility for use of the values for screening-level assessments.

  5. Predicted effectiveness of in-situ activated carbon amendment for field sediment sites with variable site- and compound-specific characteristics

    International Nuclear Information System (INIS)

    Choi, Yongju; Cho, Yeo-Myoung; Luthy, Richard G.; Werner, David

    2016-01-01

    Highlights: • The model accounts for the heterogeneity of AC distribution in field applications. • AC amendment effectiveness is predicted for ten sediment sites. • An HOC mass transfer model and calibrated parameters provide reliable predictions. • AC amendment is predicted to be effective for most sites. • K ow , K d , and equilibrium-based calculations are useful indicators. - Abstract: A growing body of evidence shows that the effectiveness of in-situ activated carbon (AC) amendment to treat hydrophobic organic contaminants (HOCs) in sediments can be reliably predicted using a mass transfer modeling approach. This study analyzes available field data for characterizing AC-sediment distribution after mechanical mixing of AC into sediment. Those distributions are used to develop an HOC mass transfer model that accounts for plausible heterogeneities resulting from mixing of AC into sediment. The model is applied to ten field sites in the U.S. and Europe with 2–3 representative HOCs from each site using site- and HOC-specific model parameters collected from the literature. The model predicts that the AC amendment reduces the pore-water HOC concentrations by more than 95% fifteen years after AC deployment for 18 of the 25 total simulated cases when the AC is applied at doses of 1.5 times sediment total organic carbon content with an upper limit of 5 dry wt%. The predicted effectiveness shows negative correlation with the HOC octanol–water partitioning coefficients and the sediment-water distribution coefficients, and positive correlation with the effectiveness calculated based on equilibrium coefficients of sediment and AC, suggesting the possibility for use of the values for screening-level assessments.

  6. Quantifying Construction Site Sediment Discharge Risk and Treatment Potential

    Science.gov (United States)

    Ferrell, L.; Beighley, R. E.

    2006-12-01

    Dealing with soil erosion and sediment transport can be a significant challenge during the construction process due to the potentially large spatial and temporal extent and conditions of bare soils. Best Management Practices (BMP) are commonly used to eliminate or reduce offsite discharge of sediment. However, few efforts have investigated the time varying risk of sediment discharge from construction sites, which often have dynamic soil conditions and the potential for less than optimal BMP installations. The goal of this research is to improve the design, implementation and effectiveness of sediment and erosion control at construction sites using site specific, temporal distributions of sediment discharge risk. Sediment risk is determined from individual factors leading to sediment expert, such as rainfall frequency, the adequacy of BMP installations, and the extent and duration of bare soil conditions. This research specifically focuses on quantifying: (a) the effectiveness of temporary sediment and control erosion control BMPs in preventing, containing, and/or treating construction site sediment discharge at varying levels of "proper" installation, and (b) sediment discharge potential from construction sites during different phases of construction, (ex., disturbed earth operations). BMPs are evaluated at selected construction sites in southern California and at the Soil Erosion Research Laboratory (SERL) in the Civil and Environmental Engineering department at San Diego State University. SERL experiments are performed on a 3-m by 10-m tilting soil bed with soil depths up to 1 meter, slopes ranging from 0 to 50 percent, and rainfall rates up to 150 mm/hr (6 in/hr). BMP performance is assessed based on experiments where BMPs are installed per manufacture specifications, potential less than optimal installations, and no treatment conditions. Soil conditions are also varied to represent site conditions during different phases of construction (i.e., loose lifts

  7. Site-specific sediment clean-up objectives developed by the sediment quality triad

    International Nuclear Information System (INIS)

    Redman, S.; Janisch, T.

    1995-01-01

    Sediment chemistry, sediment toxicity, and benthic macroinvertebrate community data were collected and evaluated in concert (1) to characterize adverse effects of hydrocarbon and metal contaminants in the sediments of a small inlet of Superior Bay, Lake Superior and a tributary creek and (2) to derive numeric objectives for the clean up of this system. Sediments from reference locations and eight study sites were analyzed for a range of contaminants, including hydrocarbons (measured both as diesel range organics (DRO) and oil and grease), lead, chromium, and ammonia. A range of sediment toxicity was observed across the eight study sites using a variety of tests and endpoints: Hyalella azteca (10 day survival and growth), Chironomus tentans (10 day survival and growth), Ceriodaphnia dubia (48 hour survival), and Daphnia magna (48 hour survival and 10 day survival and reproduction). A range of alterations of the benthic macroinvertebrate community compared with communities from reference locations were observed. Benthic community alterations were summarized quantitatively by taxa richness and Shannon-Weiner mean diversity. Lowest effect levels determined through this study included 150 microg/g dry sediment for DRO (as measured in this study) and 40 microg/g dry sediment for lead. Effects thresholds determined through this study included 1,500 microg/g dry sediment for DRO and 90 microg/g dry sediment for lead. These levels and concentrations measured in relevant reference locations are being used to define objectives for sediment clean up in the inlet and creek

  8. Sediment quality criteria: A review with recommendations for developing criteria for the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Driver, C.J.

    1994-05-01

    Criteria for determining the quality of liver sediment are necessary to ensure that concentrations of contaminants in aquatic systems are within acceptable limits for the protection of aquatic and human life. Such criteria should facilitate decision-making about remediation, handling, and disposal of contaminants. Several approaches to the development of sediment quality criteria (SQC) have been described and include both descriptive and numerical methods. However, no single method measures all impacts at all times to all organisms (U.S. EPA 1992b). The U.S. EPA`s interest is primarily in establishing chemically based, numerical SQC that are applicable nation-wide (Shea 1988). Of the approaches proposed for SQC development, only three are being considered for numerical SQC on a national level. These approaches include an Equilibrium Partitioning Approach, a site-specific method using bioassays (the Apparent Effects Threshold Approach), and an approach similar to EPA`s water quality criteria (Pavlou and Weston 1984). Although national (or even regional) criteria address a number of political, litigative, and engineering needs, some researchers feel that protection of benthic communities require site-specific, biologically based criteria (Baudo et al. 1990). This is particularly true for areas where complex mixtures of contaminants are present in sediments. Other scientifically valid and accepted procedures for freshwater SQC include a background concentration approach, methods using field or spiked bioassays, a screening level concentration approach, the Apparent Effects Threshold Approach, the Sediment Quality Triad, the International Joint Commission Sediment Assessment Strategy, and the National Status and Trends Program Approach. The various sediment assessment approaches are evaluated for application to the Hanford Reach and recommendations for Hanford Site sediment quality criteria are discussed.

  9. Evaluating Sediment Mobility for Siting Nearshore Berms

    Science.gov (United States)

    2016-04-01

    placement of dredged sediment that may contain more fine silts and clays than are allowed for placement directly on the beach. The United States Army...used in the density and viscosity calculations. For this technical note an example study site is selected and the sediment mobility indexes are...acceleration due to gravity, sρ is the sediment density, ρ is the water density, v is the kinematic viscosity of water, crθ is the Shields

  10. Quantifying and modeling soil erosion and sediment export from construction sites in southern California

    Science.gov (United States)

    Wernet, A. K.; Beighley, R. E.

    2006-12-01

    Soil erosion is a power process that continuously alters the Earth's landscape. Human activities, such as construction and agricultural practices, and natural events, such as forest fires and landslides, disturb the landscape and intensify erosion processes leading to sudden increases in runoff sediment concentrations and degraded stream water quality. Understanding soil erosion and sediment transport processes is of great importance to researchers and practicing engineers, who routinely use models to predict soil erosion and sediment movement for varied land use and climate change scenarios. However, existing erosion models are limited in their applicability to constructions sites which have highly variable soil conditions (density, moisture, surface roughness, and best management practices) that change often in both space and time. The goal of this research is to improve the understanding, predictive capabilities and integration of treatment methodologies for controlling soil erosion and sediment export from construction sites. This research combines modeling with field monitoring and laboratory experiments to quantify: (a) spatial and temporal distribution of soil conditions on construction sites, (b) soil erosion due to event rainfall, and (c) potential offsite discharge of sediment with and without treatment practices. Field sites in southern California were selected to monitor the effects of common construction activities (ex., cut/fill, grading, foundations, roads) on soil conditions and sediment discharge. Laboratory experiments were performed in the Soil Erosion Research Laboratory (SERL), part of the Civil and Environmental Engineering department at San Diego State University, to quantify the impact of individual factors leading to sediment export. SERL experiments utilize a 3-m by 10-m tilting soil bed with soil depths up to 1 m, slopes ranging from 0 to 50 percent, and rainfall rates up to 150 mm/hr (6 in/hr). Preliminary modeling, field and laboratory

  11. Application of dimensionless sediment rating curves to predict suspended-sediment concentrations, bedload, and annual sediment loads for rivers in Minnesota

    Science.gov (United States)

    Ellison, Christopher A.; Groten, Joel T.; Lorenz, David L.; Koller, Karl S.

    2016-10-27

    Consistent and reliable sediment data are needed by Federal, State, and local government agencies responsible for monitoring water quality, planning river restoration, quantifying sediment budgets, and evaluating the effectiveness of sediment reduction strategies. Heightened concerns about excessive sediment in rivers and the challenge to reduce costs and eliminate data gaps has guided Federal and State interests in pursuing alternative methods for measuring suspended and bedload sediment. Simple and dependable data collection and estimation techniques are needed to generate hydraulic and water-quality information for areas where data are unavailable or difficult to collect.The U.S. Geological Survey, in cooperation with the Minnesota Pollution Control Agency and the Minnesota Department of Natural Resources, completed a study to evaluate the use of dimensionless sediment rating curves (DSRCs) to accurately predict suspended-sediment concentrations (SSCs), bedload, and annual sediment loads for selected rivers and streams in Minnesota based on data collected during 2007 through 2013. This study included the application of DSRC models developed for a small group of streams located in the San Juan River Basin near Pagosa Springs in southwestern Colorado to rivers in Minnesota. Regionally based DSRC models for Minnesota also were developed and compared to DSRC models from Pagosa Springs, Colorado, to evaluate which model provided more accurate predictions of SSCs and bedload in Minnesota.Multiple measures of goodness-of-fit were developed to assess the effectiveness of DSRC models in predicting SSC and bedload for rivers in Minnesota. More than 600 dimensionless ratio values of SSC, bedload, and streamflow were evaluated and delineated according to Pfankuch stream stability categories of “good/fair” and “poor” to develop four Minnesota-based DSRC models. The basis for Pagosa Springs and Minnesota DSRC model effectiveness was founded on measures of goodness

  12. Evaluation of surficial sediment toxicity and sediment physico-chemical characteristics of representative sites in the Lagoon of Venice (Italy)

    Science.gov (United States)

    Losso, C.; Arizzi Novelli, A.; Picone, M.; Marchetto, D.; Pessa, G.; Molinaroli, E.; Ghetti, P. F.; Volpi Ghirardini, A.

    2004-11-01

    Toxic hazard in sites with varying types and levels of contamination in the Lagoon of Venice was estimated by means of toxicity bioassays based on the early life-stages of the autochthonous sea urchin Paracentrotus lividus. Elutriate was chosen as the test matrix, due to its ability to highlight potential toxic effects towards sensitive biological components of the water column caused by sediment resuspension phenomena affecting the Lagoon. Surficial sediments (core-top 5 cm deep), directly influenced by resuspension/redeposition processes, and core sediments (core 20 cm deep), recording time-mediated contamination, were sampled in some sites located in the lagoonal area most greatly influenced by anthropogenic activities. Particle size, organic matter and water content were also analysed. In two sites, the results of physical parameters showed that the core-top sediments were coarser than the 20-cm core sediments. Sperm cell toxicity test results showed the negligible acute toxicity of elutriates from all investigated sites. The embryo toxicity test demonstrated a short-term chronic toxicity gradient for elutriates from the 20-cm core sediments, in general agreement both with the expected contamination gradient and with results of the Microtox® solid-phase test. Elutriates of the core-top 5-cm sediments revealed a totally inverted gradient, in comparison with that for the 20-cm core sediments, and the presence of a "hot spot" of contamination in the site chosen as a possible reference. Investigations on ammonia and sulphides as possible confounding factors excluded their contribution to this "hot spot". Integrated physico-chemical and toxicity results on sediments at various depths demonstrated the presence of disturbed sediments in the central basin of the Lagoon of Venice.

  13. An evaluation of contaminated estuarine sites using sediment quality guidelines and ecological assessment methodologies.

    Science.gov (United States)

    Fulton, M; Key, P; Wirth, E; Leight, A K; Daugomah, J; Bearden, D; Sivertsen, S; Scott, G

    2006-10-01

    Toxic contaminants may enter estuarine ecosystems through a variety of pathways. When sediment contaminant levels become sufficiently high, they may impact resident biota. One approach to predict sediment-associated toxicity in estuarine ecosystems involves the use of sediment quality guidelines (ERMs, ERLs) and site-specific contaminant chemistry while a second approach utilizes site-specific ecological sampling to assess impacts at the population or community level. The goal of this study was to utilize an integrated approach including chemical contaminant analysis, sediment quality guidelines and grass shrimp population monitoring to evaluate the impact of contaminants from industrial sources. Three impacted sites and one reference site were selected for study. Grass shrimp populations were sampled using a push-netting approach. Sediment samples were collected at each site and analyzed for metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and pesticides. Contaminant levels were then compared to sediment quality guidelines. In general, grass shrimp population densities at the sites decreased as the ERM quotients increased. Grass shrimp densities were significantly reduced at the impacted site that had an ERM exceedance for chromium and the highest Mean ERM quotient. Regression analysis indicated that sediment chromium concentrations were negatively correlated with grass shrimp density. Grass shrimp size was reduced at two sites with intermediate levels of contamination. These findings support the use of both sediment quality guidelines and site-specific population monitoring to evaluate the impacts of sediment-associated contaminants in estuarine systems.

  14. Trace Metal Content of Sediments Close to Mine Sites in the Andean Region

    Directory of Open Access Journals (Sweden)

    Cristina Yacoub

    2012-01-01

    Full Text Available This study is a preliminary examination of heavy metal pollution in sediments close to two mine sites in the upper part of the Jequetepeque River Basin, Peru. Sediment concentrations of Al, As, Cd, Cu, Cr, Fe, Hg, Ni, Pb, Sb, Sn, and Zn were analyzed. A comparative study of the trace metal content of sediments shows that the highest concentrations are found at the closest points to the mine sites in both cases. The sediment quality analysis was performed using the threshold effect level of the Canadian guidelines (TEL. The sediment samples analyzed show that potential ecological risk is caused frequently at both sites by As, Cd, Cu, Hg, Pb, and Zn. The long-term influence of sediment metals in the environment is also assessed by sequential extraction scheme analysis (SES. The availability of metals in sediments is assessed, and it is considered a significant threat to the environment for As, Cd, and Sb close to one mine site and Cr and Hg close to the other mine site. Statistical analysis of sediment samples provides a characterization of both subbasins, showing low concentrations of a specific set of metals and identifies the main characteristics of the different pollution sources. A tentative relationship between pollution sources and possible ecological risk is established.

  15. Technetium-99m: From nuclear medicine applications to fine sediment transport studies

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    Bandeira Jefferson V.

    2017-12-01

    Full Text Available The present work is a contribution to rescue the history of development of the application of 99mTc, widely used in nuclear medicine, to its use as tracer for the study of the transport of fine sediment in suspension, in water environment. It addresses the usefulness of its application in obtaining important parameters in environmental studies, illustrating them with some applications already performed and the results obtained. This kind of study, when associated with information on hydrodynamic parameters, for example, river, tidal, wind and wave currents, are powerful tools for the understanding and quantification of fine sediment transport in suspension. Fine sediment is an important vector in the transportation of heavy metals, organic matter and nutrients in water environment, and the quantitative knowledge of its behaviour is mandatory for studies of environmental impacts. Fine sediment labelled with 99mTc, can also be used to study the effect of human interventions, such as dredging of reservoirs, access channels and harbours, and the dumping of dredged materials in water bodies. Besides that, it can be used to optimize dredging works, evaluating the technical and economic feasibility of dumping sites and their environmental impact. It is a valuable support in the calibration and validation of mathematical models for sediment dynamics.

  16. Uranium(VI) sorption on iron oxides in Hanford Site sediment: Application of a surface complexation model

    International Nuclear Information System (INIS)

    Um, Wooyong; Serne, R. Jeffrey; Brown, Christopher F.; Rod, Kenton A.

    2008-01-01

    Sorption of U(VI) on Hanford fine sand (HFS) with varying Fe-oxide (especially ferrihydrite) contents showed that U(VI) sorption increased with the incremental addition of synthetic ferrihydrite into HFS, consistent with ferrihydrite being one of the most reactive U(VI) sorbents present in natural sediments. Surface complexation model (SCM) calculations for U(VI) sorption, using only U(VI) surface-reaction constants obtained from U(VI) sorption data on freshly synthesized ferrihydrite at different pHs, were similar to the measured U(VI) sorption results on pure synthetic ferrihydrite and on HFS with high contents of ferrihydrite (5 wt%) added. However, the SCM prediction using only U(VI) sorption reactions and constants for synthetic ferrihydrite overestimated U(VI) sorption on the natural HFS or HFS with addition of low amounts of added ferrihydrite (1 wt% added). Over-predicted U(VI) sorption was attributed to reduced reactivity of natural ferrihydrite present in Hanford Site sediments, compared to freshly prepared synthetic ferrihydrite. Even though the SCM general composite (GC) approach is considered to be a semi-quantitative estimation technique for contaminant sorption, which requires systematic experimental data on the sorbent-sorbate system being studied to obtain credible SCM parameters, the general composite SCM model was still found to be a useful technique for describing U(VI) sorption on natural sediments. Based on U(VI) batch sorption results, two simple U(VI) monodentate surface species, SO U O 2 HCO 3 and SO U O 2 OH on ferrihydrite and phyllosillicate in HFS, respectively, can be successfully used to describe U(VI) sorption onto Hanford Site sediment contacting varying geochemical solutions

  17. In situ groundwater and sediment bioremediation: barriers and perspectives at European contaminated sites.

    Science.gov (United States)

    Majone, Mauro; Verdini, Roberta; Aulenta, Federico; Rossetti, Simona; Tandoi, Valter; Kalogerakis, Nicolas; Agathos, Spiros; Puig, Sebastià; Zanaroli, Giulio; Fava, Fabio

    2015-01-25

    This paper contains a critical examination of the current application of environmental biotechnologies in the field of bioremediation of contaminated groundwater and sediments. Based on analysis of conventional technologies applied in several European Countries and in the US, scientific, technical and administrative barriers and constraints which still need to be overcome for an improved exploitation of bioremediation are discussed. From this general survey, it is evident that in situ bioremediation is a highly promising and cost-effective technology for remediation of contaminated soil, groundwater and sediments. The wide metabolic diversity of microorganisms makes it applicable to an ever-increasing number of contaminants and contamination scenarios. On the other hand, in situ bioremediation is highly knowledge-intensive and its application requires a thorough understanding of the geochemistry, hydrogeology, microbiology and ecology of contaminated soils, groundwater and sediments, under both natural and engineered conditions. Hence, its potential still remains partially unexploited, largely because of a lack of general consensus and public concerns regarding the lack of effectiveness and control, poor reliability, and possible occurrence of side effects, for example accumulation of toxic metabolites and pathogens. Basic, applied and pre-normative research are all needed to overcome these barriers and make in situ bioremediation more reliable, robust and acceptable to the public, as well as economically more competitive. Research efforts should not be restricted to a deeper understanding of relevant microbial reactions, but also include their interactions with the large array of other relevant phenomena, as a function of the truly variable site-specific conditions. There is a need for a further development and application of advanced biomolecular tools for site investigation, as well as of advanced metabolic and kinetic modelling tools. These would allow a

  18. Classification of sediments by means of Self-Organizing Maps and sediment quality guidelines in sites of the southern Spanish coastline

    Directory of Open Access Journals (Sweden)

    O. VESES

    2013-08-01

    Full Text Available This study was carried out to classify 112 marine and estuarine sites of the southern Spanish coastline (about 918 km long according to similar sediment characteristics by means of artificial neural networks (ANNs such as Self-Organizing Maps (SOM and sediment quality guidelines from a dataset consisted of 16 physical and chemical parameters including sediment granulometry, trace and major elements, total N and P and organic carbon content. The use of ANNs such as SOM made possible the classification of the sampling sites according to their similar chemical characteristics. Visual correlations between geochemical parameters were extracted due to the powerful visual characteristics (component planes of the SOM revealing that ANNs are an excellent tool to be incorporated in sediment quality assessments. Besides, almost 20% of the sites were classified as medium-high or high priority sites in order to take future remediation actions due to their high mean Effects Range-Median Quotient (m-ERMQ value. Priority sites included the estuaries of the major rivers (Tinto, Odiel, Palmones, etc. and several locations along the eastern coastline.

  19. Development, evaluation, and application of sediment quality targets for assessing and managing contaminated sediments in Tampa Bay, Florida

    Science.gov (United States)

    MacDonald, D.D.; Carr, R.S.; Eckenrod, D.; Greening, H.; Grabe, S.; Ingersoll, C.G.; Janicki, S.; Janicki, T.; Lindskoog, R.A.; Long, E.R.; Pribble, R.; Sloane, G.; Smorong, D.E.

    2004-01-01

    Tampa Bay is a large, urban estuary that is located in west central Florida. Although water quality conditions represent an important concern in this estuary, information from numerous sources indicates that sediment contamination also has the potential to adversely affect aquatic organisms, aquatic-dependent wildlife, and human health. As such, protecting relatively uncontaminated areas of the bay from contamination and reducing the amount of toxic chemicals in contaminated sediments have been identified as high-priority sediment management objectives for Tampa Bay. To address concerns related to sediment contamination in the bay, an ecosystem-based framework for assessing and managing sediment quality conditions was developed that included identification of sediment quality issues and concerns, development of ecosystem goals and objectives, selection of ecosystem health indicators, establishment of metrics and targets for key indicators, and incorporation of key indicators, metrics, and targets into watershed management plans and decision-making processes. This paper describes the process that was used to select and evaluate numerical sediment quality targets (SQTs) for assessing and managing contaminated sediments. These SQTs included measures of sediment chemistry, whole-sediment and pore-water toxicity, and benthic invertebrate community structure. In addition, the paper describes how the SQTs were used to develop site-specific concentration-response models that describe how the frequency of adverse biological effects changes with increasing concentrations of chemicals of potential concern. Finally, a key application of the SQTs for defining sediment management areas is discussed.

  20. Sorption of trace cesium on 21 Hanford Site sediment types

    International Nuclear Information System (INIS)

    Routson, R.C.; Barney, G.S.; Smith, R.M.; Delegard, C.A.

    1980-03-01

    Sorption of trace cesium (Cs) was measured on 21 Hanford Site sediment types. A Box-Behnken statistical design was used to develop empirical-statistical equations predicting 137 Cs sorption as a function of the equilibrium concentrations of macroions Na + , K + , and Ca +2 in solution over the concentration ranges of 3.0 to 0.001M, 0.2 to 0.002M, and 0.2 to 0.002M, respectively. These equations are required to estimate trace Cs transport from Hanford ground disposal sites. Average Cs sorption equations for the 21 sediments will be presented and discussed

  1. APPLICATION OF SEDIMENT QUALITY GUIDELINES IN THE ASSESSMENT OF MANGROVE SURFACE SEDIMENT IN MENGKABONG LAGOON, SABAH, MALAYSIA

    Directory of Open Access Journals (Sweden)

    S. M. Praveena, M. Radojevic, M. H. Abdullah, A. Z. Aris

    2008-01-01

    Full Text Available There have been numerous sediment quality guidelines developed to monitor the sediments. Sediment quality guidelines are very useful to screen sediment contamination by comparing sediment contaminant concentration with the corresponding quality guideline, provide useful tools for screening sediment chemical data to identify pollutants of concern and prioritise problem sites and relatively good predictors of contaminations. However, these guidelines are chemical specific and do not include biological parameters. Aquatic ecosystems, including sediments, must be assessed in multiple components (biological data, toxicity, physicochemistry by using intregrated approaches in order to establish a complete and comprehensive set of sediment quality guidelines. Numerous sediment quality guidelines Washington Department of Ecology Sediment Quality Guideline, Australian and New Zealand Environment and Conservation Council, Swedish Environmental Sediment Quality, Screening Quick Reference Table, Portuguese Legislation on the Classification of Dredged Materials in Coastal Zones and Interim Sediment Quality Guideline for Hong Kong have been applied to the Mengkabong lagoon mangrove sediment and discussed. The most appropriate guideline that meets the prioritization criteria consistent with international initiatives and regulations is interim sediment quality values for Hong Kong. The guideline verifies that all the metals are below the Interim Sediment Quality Value-low. However, site-specific, biological testing and ecological analysis of exisiting benthics community structure related to sediment contamination are needed for final decision making in the case of Mengkabong lagoon.

  2. Contaminants in surface water and sediments near the Tynagh silver mine site, County Galway, Ireland

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, A. [School of Planning, Architecture and Civil Engineering, Queen' s University of Belfast, Belfast, Northern Ireland (United Kingdom); Phillips, D.H., E-mail: d.phillips@qub.ac.uk [School of Planning, Architecture and Civil Engineering, Queen' s University of Belfast, Belfast, Northern Ireland (United Kingdom); Bowen, J. [School of Planning, Architecture and Civil Engineering, Queen' s University of Belfast, Belfast, Northern Ireland (United Kingdom); Sen Gupta, B. [School of the Built Environment, Hariot-Watt University, Edinburgh, Scotland (United Kingdom)

    2015-04-15

    A former silver mine in Tynagh, Co. Galway, Ireland is one of the most contaminated mine sites in Europe with maximum concentrations of Zn, As, Pb, Mn, Ni, Cu, and Cd far exceeding guideline values for water and sediment. The aims of this research were to 1) further assess the contamination, particularly metals, in surface water and sediment around the site, and 2) determine if the contamination has increased 10 years after the Environmental Protection Agency Ireland (EPAI) identified off-site contamination. Site pH is alkaline to neutral because CaCO{sub 3}-rich sediment and rock material buffer the exposed acid generating sulphide-rich ore. When this study was compared to the previous EPAI study conducted 10 years earlier, it appeared that further weathering of exposed surface sediment had increased concentrations of As and other potentially toxic elements. Water samples from the tailings ponds and adjacent Barnacullia Stream had concentrations of Al, Cd, Mn, Zn and Pb above guideline values. Lead and Zn concentrations from the tailings pond sediment were 16 and 5 times higher, respectively, than concentrations reported 10 years earlier. Pb and Zn levels in most sediment samples exceeded the Expert Group (EGS) guidelines of 1000 and 5000 mg/kg, respectively. Arsenic concentrations were as high as 6238 mg/kg in the tailings ponds sediment, which is 62 and 862 times greater than the EGS and Canadian Soil Quality Guidelines (CSQG), respectively. Cadmium, Cu, Fe, Mn, Pb and Zn concentrations in water and sediment were above guideline values downstream of the site. Additionally, Fe, Mn and organic matter (OM) were strongly correlated and correlated to Zn, Pb, As, Cd, Cu and Ni in stream sediment. Therefore, the nearby Barnacullia Stream is also a significant pathway for contaminant transport to downstream areas. Further rehabilitation of the site may decrease the contamination around the area. - Highlights: • Tynagh silver mine in Co. Galway, Ireland is a source of

  3. Radiological impact of surface water and sediment near uranium mining sites.

    Science.gov (United States)

    Ivanova, K; Stojanovska, Z; Badulin, V; Kunovska, B; Yovcheva, M

    2015-12-01

    The aim of this study is to assess the radiological impact of surface water and sediment around uranium mining sites 20 years after their closing. The areas under observations are 31 former classical underground uranium mining and exploratory sites in Bulgaria, named as objects. The extraction and processing of uranium ores in the Republic of Bulgaria were ended in 1992. To assess the radiological impact of radionuclides field expeditions were performed to sample water and bottom sediment. The migration of uranium through surface water was examined as one of the major pathways for contamination spread. The range of uranium concentration in water flowing from the mining sites was from 0.012 to 6.8 mgU l(-1) with a geometric mean of 0.192 mgU l(-1). The uranium concentrations in water downstream the mining sites were approximately 3 times higher than the background value (upstream). The concentrations of Unat, (226)Ra, (210)Pb, and (232)Th in the sediment of downstream river were higher than those upstream by 3.4, 2.6, 2, and 1.7 times, respectively. The distribution coefficient of uranium reflects its high mobility in most of the sites. In order to evaluate the impact on people as well as site prioritization for more detailed assessment and water management, screening dose assessments were done.

  4. Suspended sediments from upstream tributaries as the source of downstream river sites

    Science.gov (United States)

    Haddadchi, Arman; Olley, Jon

    2014-05-01

    Understanding the efficiency with which sediment eroded from different sources is transported to the catchment outlet is a key knowledge gap that is critical to our ability to accurately target and prioritise management actions to reduce sediment delivery. Sediment fingerprinting has proven to be an efficient approach to determine the sources of sediment. This study examines the suspended sediment sources from Emu Creek catchment, south eastern Queensland, Australia. In addition to collect suspended sediments from different sites of the streams after the confluence of tributaries and outlet of the catchment, time integrated suspended samples from upper tributaries were used as the source of sediment, instead of using hillslope and channel bank samples. Totally, 35 time-integrated samplers were used to compute the contribution of suspended sediments from different upstream waterways to the downstream sediment sites. Three size fractions of materials including fine sand (63-210 μm), silt (10-63 μm) and fine silt and clay (<10 μm) were used to find the effect of particle size on the contribution of upper sediments as the sources of sediment after river confluences. And then samples were analysed by ICP-MS and -OES to find 41 sediment fingerprints. According to the results of Student's T-distribution mixing model, small creeks in the middle and lower part of the catchment were major source in different size fractions, especially in silt (10-63 μm) samples. Gowrie Creek as covers southern-upstream part of the catchment was a major contributor at the outlet of the catchment in finest size fraction (<10 μm) Large differences between the contributions of suspended sediments from upper tributaries in different size fractions necessitate the selection of appropriate size fraction on sediment tracing in the catchment and also major effect of particle size on the movement and deposition of sediments.

  5. Phytoremediation as a management option for contaminated sediments in tidal marshes, flood control areas and dredged sediment landfill sites.

    Science.gov (United States)

    Bert, Valérie; Seuntjens, Piet; Dejonghe, Winnie; Lacherez, Sophie; Thuy, Hoang Thi Thanh; Vandecasteele, Bart

    2009-11-01

    processes and vegetation development mainly determined by hydrology, over alluvial soils affected by overbank sedimentation (including flood control areas), to dredged sediment disposal facilities where hydrology and vegetation might be affected or managed by human intervention. This gradient is also a gradient of systems with highly variable soil and hydrological conditions in a temporal scale (tidal marshes) versus systems with a distinct soil development over time (dredged sediment landfill sites). In some circumstances (e.g. to avoid flooding or to ensure navigation) dredging operations are necessary. Management and remediation of contaminated sediments are necessary to reduce the ecological risks and risks associated with food chain contamination and leaching. Besides disposal, classical remediation technologies for contaminated sediment also extract or destroy contaminants. These techniques imply the sediment structure deterioration and prohibitive costs. On the contrary, phytoremediation could be a low-cost option, particularly suited to in situ remediation of large sites and environmentally friendly. However, phytoremediation is rarely included in the management scheme of contaminated sediment and accepted as a viable option. Phytoremediation is still an emerging technology that has to prove its sustainability at field scale. Research needs to focus on optimisations to enhance applicability and to address the economic feasibility of phytoremediation.

  6. Physicochemical and biological characterisation of different dredged sediment deposit sites in France

    International Nuclear Information System (INIS)

    Capilla, Xavier; Schwartz, Christophe; Bedell, Jean-Philippe; Sterckeman, Thibault; Perrodin, Yves; Morel, Jean-Louis

    2006-01-01

    The aim of this work is to determine sediment properties, metal contents and transfers of Cd and Zn from dredged sediments to plants. To this end 10 deposit sites with different contexts were visited in France. The main agronomic characteristics and metal contents for surface soil layers were measured, the plant species present at the sites, such as Brassicaceae and Fabaceae, were listed, and the distribution of their root systems described. Soil characteristics such as available P (Olsen) varied between sites, with values ranging from 0.01 to 0.49 g kg -1 . Total contents and enrichment factors were studied, highlighting metal contamination in most of the sites. Despite carrying out principal component analyses, it was not possible to group deposits by age or geographical localisation. However, deposits could be distinguished as a function of proximity of industrial facilities, sediment grain size and carbonate content. Associations between metals were also highlighted: (1) Cd, Pb and Zn, and (2) Al, Cr, Cu and Fe. Consequently, we propose classifying them as technogenic anthrosols. - The term technogenic arthrosols is suggested

  7. Physicochemical and biological characterisation of different dredged sediment deposit sites in France

    Energy Technology Data Exchange (ETDEWEB)

    Capilla, Xavier [Laboratoire des Sciences de l' Environnement a l' ENTPE, Rue Maurice Audin, 69 518 Vaulx-en-Velin Cedex (France); Schwartz, Christophe [Laboratoire Sols et Environnement, INPL (ENSAIA)/INRA UMR 1120, 2 avenue de la foret de Haye, BP 172, 54 505 Vandoeuvre les Nancy (France); Bedell, Jean-Philippe [Laboratoire des Sciences de l' Environnement a l' ENTPE, Rue Maurice Audin, 69 518 Vaulx-en-Velin Cedex (France)]. E-mail: bedell@entpe.fr; Sterckeman, Thibault [Laboratoire Sols et Environnement, INPL (ENSAIA)/INRA UMR 1120, 2 avenue de la foret de Haye, BP 172, 54 505 Vandoeuvre les Nancy (France); Perrodin, Yves [Laboratoire des Sciences de l' Environnement a l' ENTPE, Rue Maurice Audin, 69 518 Vaulx-en-Velin Cedex (France); Morel, Jean-Louis [Laboratoire Sols et Environnement, INPL (ENSAIA)/INRA UMR 1120, 2 avenue de la foret de Haye, BP 172, 54 505 Vandoeuvre les Nancy (France)

    2006-09-15

    The aim of this work is to determine sediment properties, metal contents and transfers of Cd and Zn from dredged sediments to plants. To this end 10 deposit sites with different contexts were visited in France. The main agronomic characteristics and metal contents for surface soil layers were measured, the plant species present at the sites, such as Brassicaceae and Fabaceae, were listed, and the distribution of their root systems described. Soil characteristics such as available P (Olsen) varied between sites, with values ranging from 0.01 to 0.49 g kg{sup -1}. Total contents and enrichment factors were studied, highlighting metal contamination in most of the sites. Despite carrying out principal component analyses, it was not possible to group deposits by age or geographical localisation. However, deposits could be distinguished as a function of proximity of industrial facilities, sediment grain size and carbonate content. Associations between metals were also highlighted: (1) Cd, Pb and Zn, and (2) Al, Cr, Cu and Fe. Consequently, we propose classifying them as technogenic anthrosols. - The term technogenic arthrosols is suggested.

  8. Chemical Warfare Materiel in Sediment at a Deep-Water Discarded Military Munitions Site

    Science.gov (United States)

    Briggs, C. W.; Bissonnette, M. C.; Edwards, M.; Shjegstad, S. M.

    2016-12-01

    Understanding the release and transformation of chemical agent (CA) at underwater discarded military munitions (DMM) sites is essential to determine the potential risk to human health and impact on the ocean environment; yet few studies have been conducted at sites in excess of 250 m, the depth at which most U.S. CA munitions were disposed. Maritime construction workers installing cables or pipelines at a CA DMM site, as well as fishermen and scientific researchers deploying bottom-contact gear, represent possible exposure pathways to human receptors. The Hawai`i Undersea Military Munitions Assessment (HUMMA) sought to characterize a historic munitions sea-disposal site at depths between 400-650 m. During the 2014 HUMMA Sampling Survey, the Jason 2 remotely operated vehicle was used to collect sediments within two meters of suspected World War II chemical munitions, confirmed to be 100-lb M47 series bombs containing sulfur mustard. When environmental media was brought to the surface, samples were screened for distilled sulfur mustard (HD) and related agent breakdown products (ABP) (collectively referred to as chemical warfare materiel [CWM]). Detectable concentrations of HD and/or its ABP 1,4-dithiane were found in sediments collected at all CA DMM sites; HD was also detected at two control sites. The location and extent of munitions casing deterioration strongly influenced the distribution and level of CWM in sediment. The interior of the casing contained levels of CWM orders of magnitudes higher than that observed in the surrounding sediment at one meter distance, indicating the majority of the CWM is hydrolyzed as it is released from the munitions casing and a fraction of the fill materiel persists in the environment for decades following disposal. Although the potential for future site users to become exposed to CWA in recovered sediments and debris exists, the level of risk is significantly mitigated by the depth and location of the sea-disposal site.

  9. Results of bulk sediment analysis and bioassay testing on selected sediments from Oakland Inner Harbor and Alcatraz disposal site, San Francisco, California

    International Nuclear Information System (INIS)

    Word, J.Q.; Ward, J.A.; Woodruff, D.L.

    1990-09-01

    The Battelle/Marine Sciences Laboratory (MSL) was contracted by the US Army Corps of Engineers, San Francisco District, to perform bulk sediment analysis and oyster larvae bioassays (elutriate) on sediments from Inner Oakland Harbor, California. Analysis of sediment characteristics by MSL indicated elevated priority pollutants, PAHs, pesticides, metals, organotins, and oil and grease concentrations, when compared to Alcatraz Island Dredged Material Disposal Site sediment concentrations. Larvae of the Pacific oyster, Crassostrea gigas, were exposed to seawater collected from the Alcatraz Island Site water, and a series of controls using water and sediments collected from Sequim Bay, Washington. Exposure of larvae to the Alcatraz seawater and the 50% and 100% elutriate concentrations from each Oakland sediment resulted in low survival and a high proportion of abnormal larvae compared to Sequim Bay control exposures. MSL identified that field sample collection, preservation, and storage protocols used by Port of Oakland contractors were inconsistent with standard accepted practices. 23 refs., 10 figs., 40 tabs

  10. Application of a new sediment contact test with Myriophyllum aquaticum and of the Aquatic Lemna test to assess the sediment quality of Lake Skadar

    Energy Technology Data Exchange (ETDEWEB)

    Stesevic, D.; Sundic, D.; Mijovic, S. [Montenegro Univ., Podgorica (ME). Faculty of Sciences; Feiler, U.; Heininger, P. [Federal Institute of Hydrology, Koblenz (Germany); Erdinger, L. [Heidelberg Univ. (Germany). Inst. of Hygiene; Seiler, T.B.; Hollert, H. [Heidelberg Univ. (Germany). Dept. of Zoology; RWTH Aachen (Germany). Inst. fuer Umweltforschung - Biologie V

    2007-10-15

    Goal, Scope and Background: Situated in the transboundary belt between Montenegro and Albania, the Lake Skadar is the largest freshwater reservoir in Southeastern Europe. Because of the wide range of endemic, rare or endangered plant and animal species it supports, Lake Skadar and its extensive adjacent wetlands are internationally recognised as a site of significance and importance (Ramsar site). Within the last 10 to 20 years, Lake Skadar was exposed to intensive pollution. For the assessment of the ecotoxic load of the sediments sampled in Lake Skadar, a triad approach was recently applied. Overall, a complex spectrum of ecotoxic loads was elucidated. The aim of the present study was to use plant-based bioassays for assessing the sediment quality of Lake Skadar in order to facilitate and complement the triad test battery. The newly developed sediment contact test with Myriophyllum aquaticum and the aquatic growth inhibition test with Lemna minor were applied to native sediments and pore water, respectively, allowing the investigation of different toxicity-effects caused by particle-bound pollutants as well as pollutants in the interstitial water. This investigation is the first application of the novel sediment contact test with Myriophyllum aquaticum to lake sediments. Materials and Methods: Sediment samples were taken from nine selected sites at Lake Skadar and investigated by the sediment contact assay with Myriophyllum aquaticum. The pore water was extracted from these sediment samples to be analysed in the aquatic growth inhibition test with Lemna minor. The results of the sediment contact tests were compared with each other and with those of the aquatic growth inhibition test. Results and Discussion: Both applied macrophyte biotests revealed distinct changes in the growth behaviour of the two macrophytes subsequent to the exposure to the investigated natural sediments of Lake Skadar. The Myriophyllum sediment contact test revealed significant toxicity in

  11. Mining-Related Sediment and Soil Contamination in a Large Superfund Site: Characterization, Habitat Implications, and Remediation.

    Science.gov (United States)

    Juracek, K E; Drake, K D

    2016-10-01

    Historical mining activity (1850-1970) in the now inactive Tri-State Mining District provided an ongoing source of lead and zinc to the environment including the US Environmental Protection Agency Superfund site located in Cherokee County, southeast Kansas, USA. The resultant contamination adversely affected biota and caused human health problems and risks. Remediation in the Superfund site requires an understanding of the magnitude and extent of contamination. To provide some of the required information, a series of sediment and soil investigations were conducted in and near the Superfund site to characterize lead and zinc contamination in the aquatic and floodplain environments along the main-stem Spring River and its major tributaries. In the Superfund site, the most pronounced lead and zinc contamination, with concentrations that far exceed sediment quality guidelines associated with potential adverse biological effects, was measured for streambed sediments and floodplain soils located within or downstream from the most intensive mining-affected areas. Tributary streambeds and floodplains in affected areas are heavily contaminated with some sites having lead and zinc concentrations that are an order of magnitude (or more) greater than the sediment quality guidelines. For the main-stem Spring River, the streambed is contaminated but the floodplain is mostly uncontaminated. Measured lead and zinc concentrations in streambed sediments, lakebed sediments, and floodplain soils documented a persistence of the post-mining contamination on a decadal timescale. These results provide a basis for the prioritization, development, and implementation of plans to remediate contamination in the affected aquatic and floodplain environments within the Superfund site.

  12. Mining-related sediment and soil contamination in a large Superfund site: Characterization, habitat implications, and remediation

    Science.gov (United States)

    Juracek, Kyle E.; Drake, K. D.

    2016-01-01

    Historical mining activity (1850–1970) in the now inactive Tri-State Mining District provided an ongoing source of lead and zinc to the environment including the US Environmental Protection Agency Superfund site located in Cherokee County, southeast Kansas, USA. The resultant contamination adversely affected biota and caused human health problems and risks. Remediation in the Superfund site requires an understanding of the magnitude and extent of contamination. To provide some of the required information, a series of sediment and soil investigations were conducted in and near the Superfund site to characterize lead and zinc contamination in the aquatic and floodplain environments along the main-stem Spring River and its major tributaries. In the Superfund site, the most pronounced lead and zinc contamination, with concentrations that far exceed sediment quality guidelines associated with potential adverse biological effects, was measured for streambed sediments and floodplain soils located within or downstream from the most intensive mining-affected areas. Tributary streambeds and floodplains in affected areas are heavily contaminated with some sites having lead and zinc concentrations that are an order of magnitude (or more) greater than the sediment quality guidelines. For the main-stem Spring River, the streambed is contaminated but the floodplain is mostly uncontaminated. Measured lead and zinc concentrations in streambed sediments, lakebed sediments, and floodplain soils documented a persistence of the post-mining contamination on a decadal timescale. These results provide a basis for the prioritization, development, and implementation of plans to remediate contamination in the affected aquatic and floodplain environments within the Superfund site.

  13. Diffusive flux of PAHs across sediment-water and water-air interfaces at urban superfund sites.

    Science.gov (United States)

    Minick, D James; Anderson, Kim A

    2017-09-01

    Superfund sites may be a source of polycyclic aromatic hydrocarbons (PAHs) to the surrounding environment. These sites can also act as PAH sinks from present-day anthropogenic activities, especially in urban locations. Understanding PAH transport across environmental compartments helps to define the relative contributions of these sources and is therefore important for informing remedial and management decisions. In the present study, paired passive samplers were co-deployed at sediment-water and water-air interfaces within the Portland Harbor Superfund Site and the McCormick and Baxter Superfund Site. These sites, located along the Willamette River (Portland, OR, USA), have PAH contamination from both legacy and modern sources. Diffusive flux calculations indicate that the Willamette River acts predominantly as a sink for low molecular weight PAHs from both the sediment and the air. The sediment was also predominantly a source of 4- and 5-ring PAHs to the river, and the river was a source of these same PAHs to the air, indicating that legacy pollution may be contributing to PAH exposure for residents of the Portland urban center. At the remediated McCormick and Baxter Superfund Site, flux measurements highlight locations within the sand and rock sediment cap where contaminant breakthrough is occurring. Environ Toxicol Chem 2017;36:2281-2289. © 2017 SETAC. © 2017 SETAC.

  14. Ecological and human health sediment risk assessment for a hydrocarbon-impacted site in Lake Athabasca

    International Nuclear Information System (INIS)

    Mcdonald, B.; Wagenaar, A.; LaPorte, J.; Misfeldt, G.; Chatwell, I.

    2009-01-01

    The operation of a public port facility near Uranium City, Saskatchewan has resulted in elevated levels of hydrocarbons in soil, groundwater and sediment. Remedial action in the uplands portion of the site was successful and a risk management approach was initiated for the aquatic portion of the site in order to resolve human health and ecological issues. Ecological risks were assessed using a sediment weight-of-evidence approach involving chemistry, toxicity, bioaccumulation and benthic community structure. Human health risks were assessed via fish consumption, water ingestion and direct contact according to Health Canada guidance. This presentation included an overview of the general risk assessment approach as well as site-specific data and findings. The primary focus was on the challenges confronted during the risk assessment process, such as the need to include alkylated PAHs as a COPC in the human health risk assessment and to evaluate ongoing propeller wash and sediment resuspension for sediment risk management, even though the facility is no longer operational.

  15. Neutron activation analysis to the profile surface sediments from several sites on the Havana Bay

    International Nuclear Information System (INIS)

    Diaz Riso, O.; Gelen, A.; Lopez, N.; Gonzalez, H.; Manso, M.V.; Graciano, A.M.; Nogueira, C.A.; Beltran, J.; Soto, J.

    2003-01-01

    Instrumental neutron activation analysis (INAA) technique was employed to analyze the surface sediments from several sites on the Havana Bay, Cuba. Measurements of heavy and trace elements in the sediments are reported. The results show that the concentration of the elements is site dependent. The data suggest that an anthropogenic input into the bay from domestic sewage and industries occurred

  16. Sedimentation and fouling of optical surfaces at the ANTARES site

    Science.gov (United States)

    ANTARES Collaboration; CAU CEFREM Collaboration; Amram, P.; Anghinolfi, M.; Anvar, S.; Ardellier-Desages, F. E.; Aslanides, E.; Aubert, J.-J.; Azoulay, R.; Bailey, D.; Basa, S.; Battaglieri, M.; Bellotti, R.; Beltramelli, J.; Benhammou, Y.; Berthier, R.; Bertin, V.; Billault, M.; Blaes, R.; Bland, R. W.; Blondeau, F.; de Botton, N.; Boulesteix, J.; Brooks, C. B.; Brunner, J.; Cafagna, F.; Calzas, A.; Capone, A.; Caponetto, L.; Cârloganu, C.; Carmona, E.; Carr, J.; Cartwright, S. L.; Cecchini, S.; Ciacio, F.; Circella, M.; Compère, C.; Cooper, S.; Coyle, P.; Cuneo, S.; Danilov, M.; van Dantzig, R.; de Marzo, C.; Destelle, J.-J.; de Vita, R.; Dispau, G.; Druillole, F.; Engelen, J.; Feinstein, F.; Ferdi, C.; Festy, D.; Fopma, J.; Gallone, J.-M.; Giacomelli, G.; Goret, P.; Gournay, J.-F.; Hallewell, G.; Heijboer, A.; Hernández-Rey, J. J.; Hubbard, J. R.; Jaquet, M.; de Jong, M.; Karolak, M.; Keller, P.; Kooijman, P.; Kouchner, A.; Kudryavtsev, V. A.; Lafoux, H.; Lagier, P.; Lamare, P.; Languillat, J.-C.; Laubier, L.; Laugier, J.-P.; Leilde, B.; Le Provost, H.; Le van Suu, A.; Lo Nigro, L.; Lo Presti, D.; Loucatos, S.; Louis, F.; Lyashuk, V.; Magnier, P.; Marcelin, M.; Margiotta, A.; Masullo, R.; Mazéas, F.; Mazeau, B.; Mazure, A.; McMillan, J. E.; Migneco, E.; Millot, C.; Mols, P.; Montanet, F.; Montaruli, T.; Moscoso, L.; Musumeci, M.; Nezri, E.; Nooren, G. J.; Oberski, J. E. J.; Olivetto, C.; Oppelt-Pohl, A.; Palanque-Delabrouille, N.; Papaleo, R.; Payre, P.; Perrin, P.; Petruccetti, M.; Petta, C.; Piattelli, P.; Poinsignon, J.; Potheau, R.; Queinec, Y.; Racca, C.; Raia, G.; Randazzo, N.; Rethore, F.; Riccobene, G.; Ricol, J.-S.; Ripani, M.; Roca-Blay, V.; Romeyer, A.; Rostovstev, A.; Russo, G. V.; Sacquin, Y.; Salusti, E.; Schuller, J.-P.; Schuster, W.; Soirat, J.-P.; Souvorova, O.; Spooner, N. J. C.; Spurio, M.; Stolarczyk, T.; Stubert, D.; Taiuti, M.; Tao, C.; Thompson, L. F.; Tilav, S.; Triay, R.; Usik, A.; Valdy, P.; Valente, V.; Varlamov, I.; Vaudaine, G.; Vernin, P.; Vladimirsky, E.; Vorobiev, M.; de Witt Huberts, P.; de Wolf, E.; Zakharov, V.; Zavatarelli, S.; Zornoza, Juan de Dios; Zún~Iga, J.; Aloïsi, J.-C.; Kerhervé, Ph.; Monaco, A.

    2003-05-01

    ANTARES is a project leading towards the construction and deployment of a neutrino telescope in the deep Mediterranean Sea. The telescope will use an array of photomultiplier tubes to detect the Cherenkov light emitted by muons resulting from the interaction with matter of high energy neutrinos. In the vicinity of the deployment site the ANTARES Collaboration has performed a series of in situ measurements to study the change in light transmission through glass surfaces during immersions of several months. The average loss of light transmission is estimated to be only ~2% at the equator of a glass sphere one year after deployment. It decreases with increasing zenith angle, and tends to saturate with time. The transmission loss, therefore, is expected to remain small for the several year lifetime of the ANTARES detector whose optical modules are oriented downwards. The measurements were complemented by the analysis of the 210Pb activity profile in sediment cores and the study of biofouling on glass plates. Despite a significant sedimentation rate at the site, in the 0.02-0.05 cmyr-1 range, the sediments adhere loosely to the glass surfaces and can be washed off by water currents. Further, fouling by deposits of light-absorbing particulates is only significant for surfaces facing upwards.

  17. Long-term continuous acoustical suspended-sediment measurements in rivers - Theory, application, bias, and error

    Science.gov (United States)

    Topping, David J.; Wright, Scott A.

    2016-05-04

    It is commonly recognized that suspended-sediment concentrations in rivers can change rapidly in time and independently of water discharge during important sediment‑transporting events (for example, during floods); thus, suspended-sediment measurements at closely spaced time intervals are necessary to characterize suspended‑sediment loads. Because the manual collection of sufficient numbers of suspended-sediment samples required to characterize this variability is often time and cost prohibitive, several “surrogate” techniques have been developed for in situ measurements of properties related to suspended-sediment characteristics (for example, turbidity, laser-diffraction, acoustics). Herein, we present a new physically based method for the simultaneous measurement of suspended-silt-and-clay concentration, suspended-sand concentration, and suspended‑sand median grain size in rivers, using multi‑frequency arrays of single-frequency side‑looking acoustic-Doppler profilers. The method is strongly grounded in the extensive scientific literature on the incoherent scattering of sound by random suspensions of small particles. In particular, the method takes advantage of theory that relates acoustic frequency, acoustic attenuation, acoustic backscatter, suspended-sediment concentration, and suspended-sediment grain-size distribution. We develop the theory and methods, and demonstrate the application of the method at six study sites on the Colorado River and Rio Grande, where large numbers of suspended-sediment samples have been collected concurrently with acoustic attenuation and backscatter measurements over many years. The method produces acoustical measurements of suspended-silt-and-clay and suspended-sand concentration (in units of mg/L), and acoustical measurements of suspended-sand median grain size (in units of mm) that are generally in good to excellent agreement with concurrent physical measurements of these quantities in the river cross sections at

  18. Uncertainty and variability in laboratory derived sorption parameters of sediments from a uranium in situ recovery site

    Science.gov (United States)

    Dangelmayr, Martin A.; Reimus, Paul W.; Johnson, Raymond H.; Clay, James T.; Stone, James J.

    2018-06-01

    This research assesses the ability of a GC SCM to simulate uranium transport under variable geochemical conditions typically encountered at uranium in-situ recovery (ISR) sites. Sediment was taken from a monitoring well at the SRH site at depths 192 and 193 m below ground and characterized by XRD, XRF, TOC, and BET. Duplicate column studies on the different sediment depths, were flushed with synthesized restoration waters at two different alkalinities (160 mg/l CaCO3 and 360 mg/l CaCO3) to study the effect of alkalinity on uranium mobility. Uranium breakthrough occurred 25% - 30% earlier in columns with 360 mg/l CaCO3 over columns fed with 160 mg/l CaCO3 influent water. A parameter estimation program (PEST) was coupled to PHREEQC to derive site densities from experimental data. Significant parameter fittings were produced for all models, demonstrating that the GC SCM approach can model the impact of carbonate on uranium in flow systems. Derived site densities for the two sediment depths were between 141 and 178 μmol-sites/kg-soil, demonstrating similar sorption capacities despite heterogeneity in sediment mineralogy. Model sensitivity to alkalinity and pH was shown to be moderate compared to fitted site densities, when calcite saturation was allowed to equilibrate. Calcite kinetics emerged as a potential source of error when fitting parameters in flow conditions. Fitted results were compared to data from previous batch and column studies completed on sediments from the Smith-Ranch Highland (SRH) site, to assess variability in derived parameters. Parameters from batch experiments were lower by a factor of 1.1 to 3.4 compared to column studies completed on the same sediments. The difference was attributed to errors in solid-solution ratios and the impact of calcite dissolution in batch experiments. Column studies conducted at two different laboratories showed almost an order of magnitude difference in fitted site densities suggesting that experimental methodology

  19. Extension of 239+240Pu sediment geochronology to coarse-grained marine sediments

    Science.gov (United States)

    Kuehl, Steven A.; Ketterer, Michael E.; Miselis, Jennifer L.

    2012-01-01

    Sediment geochronology of coastal sedimentary environments dominated by sand has been extremely limited because concentrations of natural and bomb-fallout radionuclides are often below the limit of measurement using standard techniques. ICP-MS analyses of 239+240Pu from two sites representative of traditionally challenging (i.e., low concentration) environments provide a "proof of concept" and demonstrate a new application for bomb-fallout radiotracers in the study of sandy shelf-seabed dynamics. A kasten core from the New Zealand shelf in the Southern Hemisphere (low fallout), and a vibracore from the sandy nearshore of North Carolina (low particle surface area) both reveal measurable 239+240Pu activities at depth. In the case of the New Zealand site, independently verified steady-state sedimentation results in a 239+240Pu profile that mimics the expected atmospheric fallout. The depth profile of 239+240Pu in the North Carolina core is more uniform, indicating significant sediment resuspension, which would be expected in this energetic nearshore environment. This study, for the first time, demonstrates the utility of 239+240Pu in the study of sandy environments, significantly extending the application of bomb-fallout isotopes to coarse-grained sediments, which compose the majority of nearshore regions.

  20. Electrochemical peroxidation of PCBs and VOCs in superfund site water and sediments

    Energy Technology Data Exchange (ETDEWEB)

    Scrudato, R.J.; Chiarenzelli, J.R. [SUNY, Oswego, NY (United States)

    1996-12-31

    An electrochemical peroxidation (ECP) process has been developed and used to degrade polychlorinated biphenyls (PCB) and volatile organic compounds (VOC)-contaminated water, sludge, and sediments at a New York State Federal and State Superfund Site. The process involves passing an oscillating low-amperage (<10 amps) current through steel electrodes immersed in an acidified water or sediment slurry into which hydrogen peroxide (<1,000 ppm) is added. The generated free radicals attack organic compounds, including organo-metallic complexes and refractory compounds including PCBs. PCB degradation ranged from about 30% to 80% in experiments involving Federal Superfund Site sediments; total PCBs were reduced by {approximately}97% to 68%, respectively, in water and slurry collected from a State Superfund subsurface storage tank. VOC bench-scale experiments involved chloroethane, 1,1-dichloroethane, dichloromethane, 1,1,1-trichloroethane, and acetone and after a 3-min ECP treatment, degradation ranged from >94% to about 99.9%. Results indicate the ECP is a viable process to degrade organic contaminants in water and sediment suspensions. Because the treated water suspensions are acidified, select trace metal sorbed to the particulates is solubilized and therefore can be segregated from the particulates, offering a process that simultaneously degrades organic contaminants and separates trace metals. 19 refs., 1 fig., 4 tabs.

  1. Mössbauer investigations to characterize Fe lattice sites in sheet silicates and Peru Basin deep-sea sediments

    Science.gov (United States)

    Lougear, André; König, Iris; Trautwein, Alfred X.; Suess, Erwin

    A procedure to classify different Fe lattice sites, i.e., OH-group geometries, in the clay mineral content of deep-sea sediments was developed using Mössbauer spectroscopy at low temperature (77 K). This speciation is of interest with regard to the redox behavior, reactivity and color of marine sediments, since substantial iron redox transitions (associated with sediment color change) have been documented for the structural sheet silicate iron. Lattice site classification was achieved for the Fe(II) fraction, all of which is structural clay Fe(II) in the sediments under investigation. Whereas the major part of the Fe(III) is structural clay iron as well, there is a small Fe(III) fraction in oxide minerals. Therefore, further elaboration of the procedure would be required to also achieve lattice site classification for the Fe(III) fraction. Analysis of the Mössbauer spectra is based on computer fits, the input parameters of which were derived from a separate study of Fe(II)-rich pure chlorites. The procedure of classification is qualified to investigate, e.g., in laboratory experiments, the site-specific reaction rates and the effects on sediment color of iron redox transitions in the sheet silicate content of sediments. The new skills were successfully applied in environmental impact studies on the mining of polymetallic nodules from the Peru Basin deep-sea floor.

  2. Floodplain sedimentology and sediment accumulation assessment – Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Yeager, Kevin M. [Univ. of Kentucky, Lexington, KY (United States). Dept. of Earth and Environmental Sciences

    2016-01-03

    The primary goal of the larger research program, of which this work is one component, is to restore the hydrodynamics and energy gradients of targeted Savannah River Site (SRS) streams to a condition comparable to local natural streams or rivers of similar order, and to stabilize sediment transport (net degradation/aggregation) with the assumption that the faunal components of these systems will quickly recover on their own (e.g., Pen Branch; Lakly and McArthur, 2000). This work is specifically focused on the identification of near-stream floodplain areas that exhibit sediment deposition or erosion, and the quantification of these processes over a historical time scale (last ~100 years).

  3. Prediction of suspended-sediment concentrations at selected sites in the Fountain Creek watershed, Colorado, 2008-09

    Science.gov (United States)

    Stogner, Sr., Robert W.; Nelson, Jonathan M.; McDonald, Richard R.; Kinzel, Paul J.; Mau, David P.

    2013-01-01

    In 2008, the U.S. Geological Survey (USGS), in cooperation with Pikes Peak Area Council of Governments, Colorado Water Conservation Board, Colorado Springs City Engineering, and the Lower Arkansas Valley Water Conservancy District, began a small-scale pilot study to evaluate the effectiveness of the use of a computational model of streamflow and suspended-sediment transport for predicting suspended-sediment concentrations and loads in the Fountain Creek watershed in Colorado. Increased erosion and sedimentation damage have been identified by the Fountain Creek Watershed Plan as key problems within the watershed. A recommendation in the Fountain Creek Watershed plan for management of the basin is to establish measurable criteria to determine if progress in reducing erosion and sedimentation damage is being made. The major objective of this study was to test a computational method to predict local suspended-sediment loads at two sites with different geomorphic characteristics in order to evaluate the feasibility of using such an approach to predict local suspended-sediment loads throughout the entire watershed. Detailed topographic surveys, particle-size data, and suspended-sediment samples were collected at two gaged sites: Monument Creek above Woodmen Road at Colorado Springs, Colorado (USGS gage 07103970), and Sand Creek above mouth at Colorado Springs, Colorado (USGS gage 07105600). These data were used to construct three-dimensional computational models of relatively short channel reaches at each site. The streamflow component of these models predicted a spatially distributed field of water-surface elevation, water velocity, and bed shear stress for a range of stream discharges. Using the model predictions, along with measured particle sizes, the sediment-transport component of the model predicted the suspended-sediment concentration throughout the reach of interest. These computed concentrations were used with predicted flow patterns and channel morphology to

  4. Uncertainty and variability in laboratory derived sorption parameters of sediments from a uranium in situ recovery site.

    Science.gov (United States)

    Dangelmayr, Martin A; Reimus, Paul W; Johnson, Raymond H; Clay, James T; Stone, James J

    2018-06-01

    This research assesses the ability of a GC SCM to simulate uranium transport under variable geochemical conditions typically encountered at uranium in-situ recovery (ISR) sites. Sediment was taken from a monitoring well at the SRH site at depths 192 and 193 m below ground and characterized by XRD, XRF, TOC, and BET. Duplicate column studies on the different sediment depths, were flushed with synthesized restoration waters at two different alkalinities (160 mg/l CaCO 3 and 360 mg/l CaCO 3 ) to study the effect of alkalinity on uranium mobility. Uranium breakthrough occurred 25% - 30% earlier in columns with 360 mg/l CaCO 3 over columns fed with 160 mg/l CaCO 3 influent water. A parameter estimation program (PEST) was coupled to PHREEQC to derive site densities from experimental data. Significant parameter fittings were produced for all models, demonstrating that the GC SCM approach can model the impact of carbonate on uranium in flow systems. Derived site densities for the two sediment depths were between 141 and 178 μmol-sites/kg-soil, demonstrating similar sorption capacities despite heterogeneity in sediment mineralogy. Model sensitivity to alkalinity and pH was shown to be moderate compared to fitted site densities, when calcite saturation was allowed to equilibrate. Calcite kinetics emerged as a potential source of error when fitting parameters in flow conditions. Fitted results were compared to data from previous batch and column studies completed on sediments from the Smith-Ranch Highland (SRH) site, to assess variability in derived parameters. Parameters from batch experiments were lower by a factor of 1.1 to 3.4 compared to column studies completed on the same sediments. The difference was attributed to errors in solid-solution ratios and the impact of calcite dissolution in batch experiments. Column studies conducted at two different laboratories showed almost an order of magnitude difference in fitted site densities suggesting that experimental

  5. Evaluation of the toxicity of sediments from the Anniston PCB Site to the mussel Lampsilis siliquoidea

    Science.gov (United States)

    Schein, Allison; Sinclair, Jesse A.; MacDonald, Donald D.; Ingersoll, Christopher G.; Kemble, Nile E.; Kunz, James L.

    2015-01-01

    The Anniston Polychlorinated Biphenyl (PCB) Site is located in the vicinity of the municipality of Anniston in Calhoun County, in the north-eastern portion of Alabama. Although there are a variety of land-use activities within the Choccolocco Creek watershed, environmental concerns in the area have focused mainly on releases of PCBs to aquatic and riparian habitats. PCBs were manufactured by Monsanto, Inc. at the Anniston facility from 1935 to 1971. The chemicals of potential concern (COPCs) in sediments at the Anniston PCB Site include: PCBs, mercury, metals, polycyclic aromatic hydrocarbons (PAHs), organochlorine and organophosphorous pesticides, volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), and polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs). The purpose of this study was to evaluate the toxicity of PCB-contaminated sediments to the juvenile fatmucket mussel (Lampsilis siliquoidea) and to characterize relationships between sediment chemistry and the toxicity of sediment samples collected from the Anniston PCB Site using laboratory sediment testing. Samples were collected in August 2010 from OU-4 of the Anniston PCB Site, as well as from selected reference locations. A total of 32 samples were initially collected from six test sites and one reference site within the watershed. A total of 23 of these 32 samples were evaluated in 28-day whole-sediment toxicity tests conducted with juvenile mussels (L. siliquoidea). Physical and chemical characterization of whole sediment included grain size, total organic carbon (TOC), nutrients, PCBs, parent and alkylated PAHs, organochlorine pesticides, PCDD/PCDFs, total metals, simultaneously extracted metals (SEM), and acid volatile sulfide (AVS). Sediment collected from Snow Creek and Choccolocco Creek contained a variety of COPCs. Organic contaminants detected in sediment included PCBs, organochlorine pesticides, PCDDs/PCDFs, and PAHs. In general, the highest

  6. Hydrodynamics and sediment transport at Muria Peninsula NPP Site

    International Nuclear Information System (INIS)

    Heni Susiati; Berni A Subki; Harman A

    2011-01-01

    Coastal along the coast of the Muria Peninsula, particularly the location of the Muria NPP site candidate is a dynamic region, the interaction between physical oceanographic factors such as currents, waves and tides in the coastal sediments cause abrasion or accretion. Interactions have resulted in coastal dynamics needs to be considered in siting NPP is essential in order to plan. Capacity of hydro-oceanographic data is essential in order to plan the development of the Muria NPP. The process of selecting a safe site for hydro-oceanographic aspects carried out according to IAEA safety standards on site selection. For the evaluation stage of hydro oceanographic potential site (site survey stage), the analysis is more focused on the tidal along the northern coast, bathymetry, potential water resources and hydrologic systems in the Muria NPP siting locations, Jepara. The method used is a secondary, confirmation of field data collection and interpretation of modeling results. The results showed that the preparation for the construction of NPP need to be evaluated further to coastal conditions with respect to the increase coastal erosion in the area of prospective NPP siting. (author)

  7. Metal availability in a highly contaminated, dredged-sediment disposal site: field measurements and geochemical modeling.

    Science.gov (United States)

    Lions, Julie; Guérin, Valérie; Bataillard, Philippe; van der Lee, Jan; Laboudigue, Agnès

    2010-09-01

    Two complementary approaches were used to characterize arsenic and metal mobilizations from a dredged-sediment disposal site: a detailed field study combined with hydrogeochemical modeling. Contaminants in sediments were found to be mainly present as sulfides subject to oxidation. Secondary phases (carbonates, sulfates, (hydr)oxides) were also observed. Oxidative processes occurred at different rates depending on physicochemical conditions and contaminant contents in the sediment. Two distinct areas were identified on the site, each corresponding to a specific contaminant mobility behavior. In a reducing area, Fe and As were highly soluble and illustrated anoxic behavior. In well-oxygenated material, groundwater was highly contaminated in Zn, Cd and Pb. A third zone in which sediments and groundwater were less contaminated was also characterized. This study enabled us to prioritize remediation work, which should aim to limit infiltration and long-term environmental impact. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  8. Uranium in Aquatic Sediments; Where are the Guidelines?

    Energy Technology Data Exchange (ETDEWEB)

    Iles, M., E-mail: michelle.iles@ewlsciences.com.au [Earth, Water and Life Sciences Pty Ltd, Darwin (Australia)

    2014-05-15

    Sediment data has been collected on and around the Ranger uranium mine for over 20 years. This included studies such as annual routine monitoring of metal concentrations, adsorption-desorption conditions, phase associations, transport mechanism, release potential, bioaccumulation and bioconcentration etc. Building on this, performance-based monitoring of the sediments from on-site water bodies was undertaken to ascertain the spatial and temporal distribution of contaminants as a basis to determine ecological risks associated with the sediments which in turn underpins closure planning. Highlights of these studies are interpreted using an ecological risk assessment approach. Ideally interpretation of aquatic sediment contamination in Australia is guided by the national guidelines for water quality and a weighted multiple lines of evidence approach whereby the chemistry of sediments is compared with reference and guideline values and predictions of bio-availability, and biological effects data allows cause and effect relationships to be derived. However, where uranium in aquatic sediments is concerned there is a lack of national (Australian) and international guidelines that are applicable to tropical sediments and the biological effects data available are limited or confounded by other variables. In the absence of clear uranium guidelines for sediments an internationally reported “Predicted No Effect Concentration” (PNEC) for uranium in temperate sediments was used as a “pseudo-guideline” value to identify sites with concentrations that might present an environmental risk and that should be further investigated. The applicability of the PNEC to the tropical Ranger site was understandably questioned by stakeholders and peers. The issues raised highlighted the need for international guidelines for uranium in aquatic sediments for tropical and temperate climates and an internationally accepted approach for deriving same. (author)

  9. Waves, currents and sediment transport modelling at the Wave Hub site

    OpenAIRE

    Gonzalez-Santamaria, Raul

    2013-01-01

    Primary supervisory team: Qingping Zou and Shunqi Pan This research project uses an integrated modelling system to investigate the effects of a wave farm on nearshore sediment transport at the Wave Hub site. The Wave Hub project is a large scale demonstration site for the development of the operation of arrays of wave energy generation devices located at the southwest coast of the UK where multiple field measurements took place. Particular attention of this study was paid to th...

  10. Spatial Decision Assistance of Watershed Sedimentation (SDAS: Development and Application

    Directory of Open Access Journals (Sweden)

    Poerbandono

    2014-04-01

    Full Text Available This paper discusses the development and application of a spatial tool for erosion modeling named Spatial Decision Assistance of Watershed Sedimentation (SDAS. SDAS computes export (yield of sediment from watershed as product of erosion rate and sediment delivery ratio (SDR. The erosion rate is calculated for each raster grid according to a digital elevation model, soil, rain fall depth, and land cover data using the Universal Soil Loss Equation. SDR calculation is carried out for each spatial unit. A spatial unit is the smallest sub-watershed considered in the model and generated according to the TauDEM algorithm. The size of one spatial unit is assigned by the user as the minimum number of raster grids. SDR is inversely proportional to sediment resident time and controlled by rainfall, slope, soil, and land cover. Application of SDAS is demonstrated in this paper by simulating the spatial distribution of the annual sediment yield across the Citarum watershed in the northwest of Java, Indonesia. SDAS calibration was carried out based on sediment discharge observations from the upper catchment. We considered factors for hillslope flow depth and for actual and effective rainfall duration to fit the computed sediment yield to the observed sediment discharge. The computed sediment yield agreed with the observation data with a 7% mean relative accuracy.

  11. Bioavailability, ecotoxicity, and geological characteristics of trace lead in sediments from two sites on Negro River, Uruguay, South America.

    Science.gov (United States)

    Míguez, Diana M; Huertas, Raquel; Carrara, María V; Carnikián, Agustín; Bouvier, María E; Martínez, María J; Keel, Karen; Pioda, Carolina; Darré, Elena; Pérez, Ramiro; Viera, Santiago; Massa, Enrique

    2012-04-01

    Bioassays of two sites along the Rio Negro in Uruguay indicate ecotoxicity, which could be attributable to trace concentrations of lead in river sediments. Monthly samples at two sites at Baygorria and Bonete locations were analyzed for both particle size and lead. Lead was determined by atomic spectrometry in river water and sediment and particle size by sieving and sedimentation. Data showed that Baygorria's sediments have greater percentage of clay than Bonete's (20.4 and 5.8%, respectively). Lead was measurable in Baygorria's sediments, meanwhile in Bonete's, it was always below the detection limit. In water samples, lead was below detection limit at both sites. Bioassays using sub-lethal growth and survival test with Hyalella curvispina amphipod, screening with bioluminescent bacteria Photobacterium leiognathi, and acute toxicity bioassay with Pimephales promelas fish indicated toxicity at Baygorria, with much less effect at Bonete. Even though no lethal effects could be demonstrated, higher sub-lethal toxicity was found in samples from Baygorria site, showing a possible concentration of the contaminant in the clay fraction.

  12. Relating groundwater and sediment chemistry to microbial characterization at a BTEX-contaminated site

    International Nuclear Information System (INIS)

    Pfiffner, S.M.; Palumbo, A.V.; McCarthy, J.F.; Gibson, T.

    1996-01-01

    The National Center for Manufacturing Science is investigating bioremediation of petroleum hydrocarbon at a site in Belleville, Michigan. As part of this study we examined the microbial communities to help elucidate biodegradative processes currently active at the site. We observed high densities of aerobic hydrocarbon degraders and denitrifiers in the less-contaminated sediments. Low densities of iron and sulfate reducers were measured in the same sediments. In contrast, the highly-contaminated sediments showed low densities of aerobic hydrocarbon degraders and denitrifiers and high densities of iron and sulfate reducers. Methanogens were also found in these highly-contaminated sediments. These contaminated sediments also showed a higher biomass, by phospholipid fatty acids, and greater ratios of phospholipid fatty acids which indicate stress within the microbial community. Aquifer chemistry analyses indicated that the more-contaminated area was more reduced and had lower sulfate than the less-contaminated area. These conditions suggest that the subsurface environment at the highly-contaminated area had progressed into sulfate reduction and methanogensis. The less-contaminated area, although less reduced, also appeared to be progressing into primarily iron- and sulfate-reducing microbial communities. The proposed treatment to stimulate bioremediation includes addition of oxygen and nitrate. Groundwater chemistry and microbial analyses revealed significant differences resulted from the injection of dissolved oxygen and nitrate in the subsurface. These differences included increases in pH and Eh and large decreases in BTEX, dissolved iron, and sulfate concentrations at the injection well

  13. Can interpreting sediment toxicity tests a mega sites benefit from novel approaches to normalization to address batching of tests?

    Science.gov (United States)

    Sediment toxicity tests are a key tool used in Ecological Risk Assessments for contaminated sediment sites. Interpreting test results and defining toxicity is often a challenge. This is particularly true at mega sites where the testing regime is large, and by necessity performed ...

  14. Uranium (VI) Sorption and Transport in Unsaturated, Subsurface Hanford Site Sediments - Effect of Moisture Content and Sediment Texture: Final Report for Subtask 2b

    International Nuclear Information System (INIS)

    Gamerdinger, A.P.; Resch, C.T.; Kaplan, D.I.

    1998-01-01

    A series of experiments were conducted in fiscal year 1998 at the Pacific Northwest National Laboratory as part of the Immobilized Low-Activity Waste-Performance Assessment. These experiments evaluated the sorption and transport of uranium, U(VI), under conditions of partial moisture saturation that are relevant to arid region burial sites and vadose-zone far-field conditions at the Hanford Site. The focus was on measuring breakthrough curves (from which distribution coefficient [K d ] values can be calculated) for U(W) in three Hanford Site sediments that represent different texture classes in two unsaturated moisture conditions. Previous research showed that K d values measured during transport in unsaturated sediments varied with moisture saturation

  15. Fate of dispersed marine fuel oil in sediment under pre-spill application strategy

    International Nuclear Information System (INIS)

    Jian Hua

    2004-01-01

    A comparison of the movement of dispersed oil in marine sediment under two dispersant application scenarios, applied prior to and after oil being spilled overboard, was examined. The pre-spill application scenario caused much less oil to be retained in the top sediment than post-spill scenario. The difference in oil retention in the top sediment between pre- and post-spill application scenario increased with increase in fuel oil temperature. For fuel oil above 40 o C, the difference in the effect of pre-spill application strategy under various water temperatures was negligible. When soap water was used as replacement for chemical dispersant, almost one-half as much oil was retained in the top sediment as that when using chemical dispersant. The adsorption of dispersed oil to the top sediment was almost proportionally decreased with doubling of soap dosage. (Author)

  16. Phosphorus mobilization by sulfide oxidation in carbonate sediments from seagrass and unvegetated sites in the US Virgin Islands

    DEFF Research Database (Denmark)

    Jensen, Henning; Pedersen, Ole; Koch, M. R.

    PHOSPHORUS MOBILIZATION BY SULFIDE OXIDATION IN CARBONATE SEDIMENTS FROM SEAGRASS AND UNVEGETATED SITES IN THE US VIRGIN ISLANDS Sulfide produced by sulfate reduction (SR) can be oxidized by seagrass root O2 flux in shallow carbonate sediments low in Fe. The sulfuric acid produced from sulfide...... oxidation, as well as metabolic acids from aerobic respiration, has the potential to mobilize solid phase phosphorus (P) pools in support of seagrass nutrition. Fresh sediments from four US Virgin Islands sites were modestly acidified to near-neutral pH in slurries. Following sulfuric acid amendments...

  17. Modelling of soil depth and lake sediments. An application of the GeoEditor at the Forsmark site

    International Nuclear Information System (INIS)

    Vikstroem, Maria

    2005-02-01

    This report aims at describing the modelled soil depth according to three layers with different hydrogeological properties at the Forsmark site, based on available data from boreholes, observation points, seismic data and radar profiles. For the lakes in the area, the sediment has been modelled according to six layers of the most common deposits in the area. The peat layer at Stenroesmossen has also been visualized. The program used in the modelling of soil depths is the GeoEditor, which is an ArcView3.3-extension. The input data used in the model consist of 1,532 points based on seismic measurements, 31 profiles of interpreted ground penetrating radar data, 119 boreholes and 472 observation points. The western and south eastern part of the area has a low data density. In the southern parts the data density with respect to estimated bedrock elevation is low. Observation points in this area are generally not very deep and do not describe the actual bedrock elevation. They do, however, describe the minimum soil depth at each location. A detailed topographical DEM, bathymetry and map of Quaternary deposits were also used. The model is based on a three-layer-principle where each layer is assumed to have similar hydrological characteristics. The uppermost layer, Z1, is characterized by the impact from surface processes, roots and biological activity. The bottom layer, Z3, is characterized by contact with the bedrock. The middle layer, Z2, is assumed to have different hydraulic qualities than Z1 and Z3. The lake sediments have been modelled according to six classes of typical deposits. The modelled soil depths show a relatively high bedrock elevation and thus small total soil depth in the major part of the area. The median soil depth has been calculated to 1.9 m, based on model results in areas with higher data density. The maximum modelled soil depth is about 13 m, just north of Lake Stocksjoen. Generally, the sediment layers in the lakes of the area consists of a

  18. Effects of sediment application on Nyssa aquatica and Taxodium distichum saplings

    Science.gov (United States)

    Grandy, Isabel; Messina, Linda; Anemaet, Evelyn R.; Middleton, Beth A.

    2018-01-01

    The decline of Taxodium distichum forests along the Gulf Coast of North America is partly due to elevation loss and subsequent flooding. In many coastal wetlands, a common approach for coastal restoration is to rebuild elevation through the application of dredge material, but this technique has not been used widely in coastal forests due to concerns of negatively impacting trees. This experiment explored growth responses of Nyssa aquatica and T. distichumsaplings to applications of low salinity dredge material (0.08 ± 0.001 ppt) in a greenhouse setting. Compared to controls, saplings of T. distichum grown in 7 and 15 cm sediment depths had greater final height, and increased stem and total biomass. In contrast, N. aquatica did not respond to sediment application. The absence of a negative response to sediment application in these two species indicates that dredge material application has the potential to improve the ecosystem health of sinking swamp forests by raising their elevation. We recommend that field trials applying sediment additions in coastal forests include careful monitoring of ecosystem responses, including seed bank expression, seedling regeneration, and root and canopy production.

  19. Applicability of API ZYM to capture seasonal and spatial variabilities in lake and river sediments.

    Science.gov (United States)

    Patel, Drashti; Gismondi, Renee; Alsaffar, Ali; Tiquia-Arashiro, Sonia M

    2018-05-02

    Waters draining into a lake carry with them much of the suspended sediment that is transported by rivers and streams from the local drainage basin. The organic matter processing in the sediments is executed by heterotrophic microbial communities, whose activities may vary spatially and temporally. Thus, to capture and evaluate some of these variabilities in the sediments, we sampled six sites: three from the St. Clair River and three from Lake St. Clair in spring, summer, fall, and winter of 2016. At all sites and dates, we investigated the spatial and temporal variations in 19 extracellular enzyme activities using API ZYM. Our results indicated that a broad range of enzymes were found to be active in the sediments. Phosphatases, lipases, and esterases were synthesized most intensively by the sediment microbial communities. No consistent difference was found between the lake and sediment samples. Differences were more obvious between sites and seasons. Sites with the highest metabolic (enzyme) diversity reflected the capacity of the sediment microbial communities to breakdown a broader range of substrates and may be linked to differences in river and lake water quality. The seasonal variability of the enzymes activities was governed by the variations of environmental factors caused by anthropogenic and terrestrial inputs, and provides information for a better understanding of the dynamics of sediment organic matter of the river and lake ecosystems. The experimental results suggest that API ZYM is a simple and rapid enzyme assay procedure to evaluate natural processes in ecosystems and their changes.

  20. Hazard identification of contaminated sites. Ranking potential toxicity of organic sediment extracts in crustacean and fish

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, J.; Sundberg, H.; Aakerman, G.; Grunder, K.; Eklund, B.; Breitholtz, M. [Dept. of Applied Environmental Science (ITM), Stockholm Univ. (Sweden)

    2008-09-15

    Background, aim, and scope: It is well known that contaminated sediments represent a potential long-term source of pollutants to the aquatic environment. To protect human and ecosystem health, it is becoming common to remediate contaminated sites. However, the great cost associated with, e.g., dredging in combination with the large numbers of contaminated sites makes it crucial to pinpoint those sites that are in greatest need of remediation. In most European countries, this prioritization process has almost exclusively been based on chemical analyses of known substances; only seldom toxicity data has been considered. The main objective of the current study was therefore to develop a tool for hazard identification of sediment by ranking potential toxicity of organic sediment extracts in a crustacean and a fish. A secondary objective was to investigate the difference in potential toxicity between compounds with different polarities. Materials and methods Early life stages of the crustacean Nitocra spinipes and the fish Oncorhynchus mykiss, which represent organisms from different trophic levels (primary and secondary consumer) and with different routes of exposure (i.e. ingestion through food, diffusive uptake, and maternal transfer), were exposed to hexane and acetone fractions (semi-polar compounds) of sediment from five locations, ranging from heavily to low contaminated. Preliminary tests showed that the extracts were non-bioavailable to the crustacean when exposed via water, and the extracts were therefore loaded on silica gel. Rainbow trout embryos were exposed using nano-injection technique. Results and discussion Clear concentration-response relationships of both mortality and larval development were observed in all tests with N. spinipes. Also for rainbow trout, the observed effects (e.g., abnormality, hemorrhage, asymmetric yolk sac) followed a dose-related pattern. Interestingly, our results indicate that some of the locations contained toxic semi

  1. Preliminary studies of the total cation exchange capacity of sediments from two North Atlantic study sites

    International Nuclear Information System (INIS)

    Hydes, D.J.; Hill, N.C.; Clarke, H.; Carpenter, M.S.N.

    1983-01-01

    Initially four different methods of measuring total cation exchange capacity were compared. There were two chemical methods (ammonium saturation with displacement into seawater, and barium saturation followed by replacement with magnesium) and two radiochemical methods (sodium-22 and caesium-134 saturation). The barium-magnesium and sodium-22 methods were then applied to sediment samples from Core D10164Pound1K from the Nares Fracture Valley, and Core D10554Pound11K from the eastern flank of the Great Meteor Rise. The material at site 10164 is a pelagic clay whereas at site 10554 it is carbonate ooze. The total cation exchange capacities (T.C.E.C.) of samples from the two sites are similar when measured by the sodium-22 method, the mean for Core 10164 was 21.7 meq/100g and 24.4 meq/100g for Core 10554. However for Core 10554 the barium-magnesium method gives a mean of 42.8 meq/100g. The difference in T.C.E.C. measured by the two methods appears to be due to the high calcite content of core 10554 sediment. Measured exchange capacities are lower than in coastal sediments. In deep sea sediments organic matter either makes a very small contribution to the T.C.E.C. (core 10164) or actually blocks exchange sites (Core 10554). Amorphous oxides of iron and manganese contribute between 20 and 50% of the T.C.E.C. (author)

  2. Weight-of-Evidence Concepts: Introduction and Application to Sediment Management

    Science.gov (United States)

    2018-03-01

    Application to Sediment Management En vi ro nm en ta l L ab or at or y Matthew E. Bates, Olivia C. Massey, and Matthew D. Wood March 2018...Program ERDC/EL SR-18-1 March 2018 Weight-of-Evidence Concepts: Introduction and Application to Sediment Management Matthew E. Bates and Matthew D...Program Manager was Dr. Todd S. Bridges (CEERD-EMD). The work was performed by the Environmental Risk Branch (CEERD- EPR) of the Environmental

  3. Ecotoxicological assessment of sediments from the Port of Santos and the disposal sites of dredged material

    Directory of Open Access Journals (Sweden)

    Eduinetty Ceci P. M. Sousa

    2007-06-01

    Full Text Available The dredging of sediments from the Santos Channel is necessary to allow the navigation of ships operating in the Port of Santos. The disposal sites for such sediments are situated on the coastal zone, in front of the Santos Bay. The present paper aimed at evaluating the toxicity of sediments collected at the Santos Channel and at the former and current sediment disposal sites. Whole sediment tests with amphipods and elutriate assays with sea-urchin embryos were used. The samples from the Santos Channel were considered the most toxic: all the sediment samples from this area showed toxicity. Moreover, some samples from both former and new sediment disposal sites exhibited toxicity. Therefore, results showed that sediments from the studied areas present evidences of degradation; however, further studies are required to determine relationships between toxicity and contamination. Results also suggested that the disposal of dredged sediments should be re-evaluated.A dragagem dos sedimentos do Canal de Santos é necessária para permitir o trânsito de navios que operam no Porto de Santos. As áreas de disposição do material dragado estão situadas na zona costeira, em frente à Baía de Santos. Este estudo visou avaliar a qualidade dos sedimentos do Canal de Santos e das áreas de disposição atuais e antigas, utilizando testes de toxicidade de sedimento integral com anfípodos e de toxicidade de elutriatos com embriões de ouriço do mar. As amostras do Canal de Santos foram consideradas as mais tóxicas: todas as amostras dessa área foram consideradas significativamente tóxicas. Além disso, algumas amostras das áreas de disposição exibiram toxicidade. Os resultados mostraram, portanto, que os sedimentos apresentam evidências de degradação em sua qualidade, porém novos estudos devem ser conduzidos visando determinar as relações entre contaminação e toxicidade. Os resultados sugerem ainda que a disposição dos sedimentos dragados

  4. Risks to humans and wildlife from metal contamination in soils/sediments at CERCLA sites

    International Nuclear Information System (INIS)

    Hitch, J.P.; Hovatter, P.S.; Opresko, D.M.; Sample, B.; Young, R.A.

    1994-01-01

    A common problem that occurs at DOD and DOE CERCLA sites is metal contamination in soils and aquatic sediments and the protection of humans and wildlife from potential exposure to this contamination. Consequently, the authors have developed a site-specific reference dose for mercury in sediments at the Oak Ridge Reservation and site-specific cleanup levels for certain metals, including arsenic and nickel, in soils at an Army ammunition plant. Another concern during remediation of these sites is that limited data are available to determine the direct risks to indigenous wildlife. Therefore, the authors have developed toxicological benchmarks for certain metals and metal compounds to be used as screening tools to determine the potential hazard of a contaminant to representative mammalian and avian wildlife species. These values should enable the Army and DOE to more accurately determine the risks to humans and wildlife associated with exposure to these contaminated media at their sites in order to achieve a more effective remediation. This effort is ongoing at ORNL with toxicological benchmarks also being developed for metal compounds and other chemicals of concern to DOD and DOE in order to address the potential hazard to

  5. Radionuclide transport in the "sediments - water - plants" system of the water bodies at the Semipalatinsk test site.

    Science.gov (United States)

    Aidarkhanova, A K; Lukashenko, S N; Larionova, N V; Polevik, V V

    2018-04-01

    This paper provides research data on levels and character of radionuclide contamination distribution in the «sediments- water - plants » system of objects of the Semipalatinsk test site (STS). As the research objects there were chosen water bodies of man-made origin which located at the territory of "Experimental Field", "Balapan", "Telkem" and "Sary-Uzen" testing sites. For research the sampling of bottom sediments, water, lakeside and water plants was taken. Collected samples were used to determine concentration of anthropogenic radionuclides 90 Sr, 239+240 Pu, 241 Am, 137 Cs. The distribution coefficient (K d ) was calculated as the ratio of the content of radionuclides in the sediments to the content in water, and the concentration ratio (F V ) was calculated as the ratio of radionuclide content in plants to the content in sediments or soil. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Age of a prehistoric "Rodedian" cult site constrained by sediment and rock surface luminescence dating techniques

    DEFF Research Database (Denmark)

    Sohbati, Reza; Murray, Andrew; Porat, N.

    2015-01-01

    The construction age of a pavement in a “Rodedian” prehistoric cult site in Negev desert, Israel, is established by determining the burial age of (i) a cobble used in the pavement, and (ii) the underlying sediment. The quartz OSL age and the K-feldspar corrected IR50 age from the sediment...

  7. Application of Long Distance Conveyance (LDC) of Dredged Sediments to Louisiana Coastal Restoration

    Science.gov (United States)

    2011-01-01

    generally use some type of bucket for digging the sediment, then hoist or boom the load to the surface. Most common hydraulic methods use a centrifugal...sediment. The loaded bucket is hoisted to the surface and side dumped into a transportation unit, or into the disposal site. Transportation units are...Conveyance (LDC) of Dredged Sediments to Louisiana Coastal Restoration Timothy Welp Coastal and Hydraulics Laboratory U.S. Army Engineer Research

  8. The sediments of the Venice Lagoon (Italy) evaluated in a screening risk assessment approach: part I--application of international sediment quality guidelines.

    Science.gov (United States)

    Apitz, Sabine E; Barbanti, Andrea; Bocci, Martina; Carlin, Anna; Montobbio, Laura; Bernstein, Alberto Giulio

    2007-07-01

    A number of studies carried out in recent years have shown the presence of a wide range of contaminants in the Venice Lagoon. It is important to have a good understanding of the ecological quality of Venice Lagoon sediments in order to 1) define and locate areas where a threat to the environment is present and therefore an intervention is needed (i.e., in situ assessment and management); and 2) define sustainable and environmentally correct ways of managing sediments that are to be dredged for navigational purposes or in relation to other interventions (i.e., ex situ management). This study reports on a critical comparison of chemical quality of sediments in Venice Lagoon and its subregions. Data on the Venice Lagoon were compiled from several studies conducted during the past decade on surface sediment contamination; temporal variation and risks for contaminants at depth were not addressed. The comparison of observed pollutant concentrations with local and internationally used sediment quality guidelines (SQGs) was used as a tool to benchmark different sites and for a tier I (screening) ecological risk assessment. Meaning and relevance of a number of SQGs are discussed, together with the options available for carrying out the comparison with sediment data. The screening of the Venice Lagoon sediment quality is discussed from a risk-assessment perspective and appropriate values for use in an in situ-ex situ management framework are suggested. Although there were some differences depending upon which specific SQGs were applied, different SQGs provided the same general picture of screening risk in Venice Lagoon: Although there are geographic differences, median levels for several contaminants in surface sediments exceeded a number of SQGs. Many contaminants exceed threshold effects SQGs, and Hg exceeds probable effects SQGs in most sub-basins except the southern Lagoon. Venice Lagoon south has the lowest screening risk levels, Venice Lagoon central/north has the

  9. Behavior, balance and distribution of sediments within irrigation systems. Application to Pakistan

    International Nuclear Information System (INIS)

    Vabre, Alexandre

    2000-01-01

    This PhD work is part of a research program between Cemagref, CEA and IWMI. It aims at studying the sediment deposition phenomena in irrigation Systems of Pakistan. Indeed, many Systems are subject to an excessive sediment deposition that widely disturbs their functioning. A pragmatic approach of the problem is chosen, and the sediment deposition description is realized through global methods. This choice is done in order to allow the developed methods and tools to be utilized directly by the irrigation managers. A global numerical modeling method (GSM) is proposed. It lies on classical laws of sediment transport but a new formalism is proposed for the expression of the deposition. It's a relationship between the sediment trapping efficiency of a reach and its sediment transport capacity. Also, criteria are defined for the definition of homogeneous reaches in the system. An outline of GSM is implemented on a sediment deposition data set of an actual System in Pakistan (Jamrao). A measurement campaign using radio-activable tracers is then carried out on this site to complete the GSM working data set Also, such a campaign with it only is a description method of the deposition phenomena in the irrigation System. The strength of the modeling approach laws is then tested on another case study of irrigation System in Pakistan (Chashma). The results are very much encouraging because the GSM model could be calibrated and validated on several actual deposition trends with quite moderate errors for such a tool. Also, the constituted data set from the tracer campaign was found minimum and sufficient to implement the GSM. Moreover, it has been possible to use the GSM for irrigation management applications. A design criterion for stable canals is proposed. And the GSM has allowed to identify an hydraulic operational scenario on an irrigation System that decreases the deposition. The perspectives of this work are to test the GSM approach on other data sets and then to

  10. Insights into site formation at Rose Cottage Cave, South Africa, based on the analysis of sediment peels

    Science.gov (United States)

    Kloos, Peter; Miller, Christopher E.; Kritikakis, Panagiotis; Wadley, Lyn

    2016-04-01

    Rose Cottage Cave (RCC), in South Africa, has been a key site for explaining the origins of modern human behaviour and movement of early modern humans out of Africa. Nine sediment peels were made previously from the profile sections, preserving original materials that provide a record of cultural and environmental change during the late Pleistocene and Holocene. Here, we present the preliminary results of the study of the RCC sediment peels which aims to investigate site formation processes and the implications for site interpretation. Methods used include micromorphology and Fourier Transform Infrared spectroscopy coupled with detailed observations of the peels. The predominance of geogenic processes is demonstrated by the abundance of silt- and sand-sized quartz grains, which entered the site primarily through a crevice at the back of the cave. RCC lacks rich anthropogenic deposits as noted at other Middle Stone Age sites in southern Africa, but anthropogenic input to the sediment is indicated by the presence of charcoal, burnt bone, lithic fragments, fat-derived char and ashes. Clay coating fragments and chaotic microstructures demonstrate that bioturbation and colluvial reworking homogenised much of the deposit and may explain the absence of preserved bedding and rarity of combustion features. Downward movement of water through the sequence, indicated by clay coatings, is the likely cause for poor bone preservation and near lack of ashes at the site, as well as fluctuations in dose rate that have complicated luminescence dating studies. Evidence for diagenesis at the site is in the form of secondary apatite and gypsum. Sedimentary structures such as channel lag deposits and (silt and sand) laminae observed in peels dating between 60 and 35 ka BP suggest a high-energy sedimentary environment, which experienced flooding events that eroded underlying deposits and deposited large volumes of sediment. This explains why some of the post-Howiesons Poort layers contain

  11. Transport and fate of viruses in sediment and stormwater from a managed aquifer recharge site

    Science.gov (United States)

    Enteric viruses are one of the major concerns in water reclamation and reuse at managed aquifer recharge (MAR) sites. In this study, the transport and fate of bacteriophages MS2, PRD1, and FX174 were studied in sediment and stormwater (SW) collected from a MAR site in Parafield, Australia. Column ex...

  12. Applicability of the Linear Sorption Isotherm Model to Represent Contaminant Transport Processes in Site Wide Performance Assessments

    International Nuclear Information System (INIS)

    FOGWELL, T.W.; LAST, G.V.

    2003-01-01

    The estimation of flux of contaminants through the vadose zone to the groundwater under varying geologic, hydrologic, and chemical conditions is key to making technically credible and sound decisions regarding soil site characterization and remediation, single-shell tank retrieval, and waste site closures (DOE 2000). One of the principal needs identified in the science and technology roadmap (DOE 2000) is the need to improve the conceptual and numerical models that describe the location of contaminants today, and to provide the basis for forecasting future movement of contaminants on both site-specific and site-wide scales. The State of Knowledge (DOE 1999) and Preliminary Concepts documents describe the importance of geochemical processes on the transport of contaminants through the Vadose Zone. These processes have been identified in the international list of Features, Events, and Processes (FEPs) (NEA 2000) and included in the list of FEPS currently being developed for Hanford Site assessments (Soler et al. 2001). The current vision for Hanford site-wide cumulative risk assessments as performed using the System Assessment Capability (SAC) is to represent contaminant adsorption using the linear isotherm (empirical distribution coefficient, K d ) sorption model. Integration Project Expert Panel (PEP) comments indicate that work is required to adequately justify the applicability of the linear sorption model, and to identify and defend the range of K d values that are adopted for assessments. The work plans developed for the Science and Technology (S and T) efforts, SAC, and the Core Projects must answer directly the question of ''Is there a scientific basis for the application of the linear sorption isotherm model to the complex wastes of the Hanford Site?'' This paper is intended to address these issues. The reason that well documented justification is required for using the linear sorption (K d ) model is that this approach is strictly empirical and is often

  13. High-resolution insight into the competitive adsorption of heavy metals on natural sediment by site energy distribution.

    Science.gov (United States)

    Huang, Limin; Jin, Qiang; Tandon, Puja; Li, Aimin; Shan, Aidang; Du, Jiajie

    2018-04-01

    Investigating competitive adsorption on river/lake sediments is valuable for understanding the fate and transport of heavy metals. Most studies have studied the adsorption isotherms of competitive heavy metals, which mainly comparing the adsorption information on the same concentration. However, intrinsically, the concentration of each heavy metal on competitive adsorption sites is different, while the adsorption energy is identical. Thus, this paper introduced the site energy distribution theory to increase insight into the competitive adsorption of heavy metals (Cu, Cd and Zn). The site energy distributions of each metal with and without other coexisting heavy metals were obtained. It illustrated that site energy distributions provide much more information than adsorption isotherms through screening of the full energy range. The results showed the superior heavy metal in each site energy area and the influence of competitive metals on the site energy distribution of target heavy metal. Site energy distributions can further help in determining the competitive sites and ratios of coexisting metals. In particular, in the high-energy area, which has great environmental significance, the ratios of heavy metals in the competitive adsorption sites obtained for various competitive systems were as follows: slightly more than 3:1 (Cu-Cd), slightly less than 3:1 (Cu-Zn), slightly more than 1:1 (Cd-Zn), and nearly 7:2:2 (Cu-Cd-Zn). The results from this study are helpful to deeply understand competitive adsorption of heavy metals (Cu, Cd, Zn) on sediment. Therefore, this study was effective in presenting a general pattern for future reference in competitive adsorption studies on sediments. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Sediment and Runoff Losses following Harvesting/Site Prep Operations on a Piedmont Soil in Alabama

    Science.gov (United States)

    Johnny M. III Grace; Emily A. Carter

    2001-01-01

    Impacts of soil erosion on water quality from forest harvesting and site preparation have received increased concern in recent years. The study presented here was performed in Lee County, Alabama to investigate the impact of harvesting and site preparation on a 20-year-old loblolly pine (Pinus taeda L.) plantation on sediment and runoff yield....

  15. Exchangeable fraction of elements in alluvial sediments under waste disposal site (Zagreb, Croatia)

    International Nuclear Information System (INIS)

    Vertacnik, A.; Barisic, D.; Musani, Lj.; Prohic, E.; Juracic, M.

    1997-01-01

    Concentrations of Ag, Ba, Cd, Ce, Cs, Co, Cr, Eu, Fe, Rb, Sc, Sr, Th, and Zn exchangeable fractions were determined in alluvial sediments at waste disposal site area in the vicinity of water-well field. Samples have been'leached with 0.5M NH 4 Cl at a sample/solution ratio of 1:20 during 24 hours without shaking. INAA of dry NH 4 Cl residues show that the concentrations of exchangeable elements determined in the most of the sediments below the wastes have natural levels. Ag, Ba and Sr are readily exchangeable; Rb, Cs and Zn have lower exchangeability, while Cd, Ce, Th, Sc, Eu, Cr, Fe and Co are rather immobile. Extremely high total and exchangeable silver concentration was found at 6.5-6.8 meters below waste in the aerated layer occasionally under the water table. Exchangeable concentrations in deeper water-bearing sediment layers are not elevated. Due to this, one can presume that the upper sediment layers act as chemical filter generally preventing the infiltration from overlying wastes into water-bearing layers. (author)

  16. Retention and chemical speciation of uranium in an oxidized wetland sediment from the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dien; Seaman, John C.; Chang, Hyun-Shik; Jaffe, Peter R.; Koster van Groos, Paul; Jiang, De-Tong; Chen, Ning; Lin, Jinru; Arthur, Zachary; Pan, Yuanming; Scheckel, Kirk G.; Newville, Matthew; Lanzirotti, Antonio; Kaplan, Daniel I.

    2014-05-01

    Uranium speciation and retention mechanism onto Savannah River Site (SRS) wetland sediments was studied using batch (ad)sorption experiments, sequential extraction desorption tests and U L{sub 3}-edge X-ray absorption near-edge structure (XANES) spectroscopy of contaminated wetland sediments. U was highly retained by the SRS wetland sediments. In contrast to other similar but much lower natural organic matter (NOM) sediments, significant sorption of U onto the SRS sediments was observed at pH <4 and pH >8. Sequential extraction tests indicated that the U(VI) species were primarily associated with the acid soluble fraction (weak acetic acid extractable) and NOM fraction (Na-pyrophosphate extractable). Uranium L3- edge XANES spectra of the U-retained sediments were nearly identical to that of uranyl acetate. The primary oxidation state of U in these sediments was as U(VI), and there was little evidence that the high sorptive capacity of the sediments could be ascribed to abiotic or biotic reduction to the less soluble U(IV) species. The molecular mechanism responsible for the high U retention in the SRS wetland sediments is likely related to the chemical bonding of U to organic carbon.

  17. Multielemental analysis to the profile sediments from several sites on the Havana Bay, by the Neutron activation analysis

    International Nuclear Information System (INIS)

    Diaz Riso, O.; Gelen, A.; Lopez, N.; Manso, M.V.; Graciano, A.M.; Nogueira, C.A.; Beltran, J.

    2003-01-01

    Instrumental neutron activation analysis (INAA) technique was employed to analyze the profile sediments from several sites on the Havana Bay, Cuba. Measurements of 24 heavy and trace elements in the sediments are reported. The results show the increment in the sediment pollution occurred in the 70-80 years of the last century. The data confirm that an anthropogenic input into the bay from domestic sewage and industries occurred

  18. Use of rare earth oxides as tracers to identify sediment source areas for agricultural hillslopes

    Directory of Open Access Journals (Sweden)

    C. Deasy

    2010-11-01

    Full Text Available Understanding sediment sources is essential to enable more effective targeting of in-field mitigation approaches to reduce diffuse pollution from agricultural land. In this paper we report on the application of rare earth element oxides to arable soils at hillslope scale in order to determine sediment source areas and their relative importance, using a non-intrusive method of surface spraying. Runoff, sediments and rare earth elements lost from four arable hillslope lengths at a site in the UK with clay soils were monitored from three rainfall events after tracer application. Measured erosion rates were low, reflecting the typical event conditions occurring at the site, and less than 1% of the applied REO tracers were recovered, which is consistent with the results of comparable studies. Tracer recovery at the base of the hillslope was able to indicate the relative importance of different hillslope sediment source areas, which were found to be consistent between events. The principal source of eroded sediments was the upslope area, implying that the wheel tracks were principally conduits for sediment transport, and not highly active sites of erosion. Mitigation treatments for sediment losses from arable hillslopes should therefore focus on methodologies for trapping mobile sediments within wheel track areas through increasing surface roughness or reducing the connectivity of sediment transport processes.

  19. Distribution of chemical warfare agent, energetics, and metals in sediments at a deep-water discarded military munitions site

    Science.gov (United States)

    Briggs, Christian; Shjegstad, Sonia M.; Silva, Jeff A. K.; Edwards, Margo H.

    2016-06-01

    There is a strong need to understand the behavior of chemical warfare agent (CWA) at underwater discarded military munitions (DMM) sites to determine the potential threat to human health or the environment, yet few studies have been conducted at sites in excess of 250 m, the depth at which most U.S. chemical munitions were disposed. As part of the Hawai'i Undersea Military Munitions Assessment (HUMMA), sediments adjacent to chemical and conventional DMM at depths of 400-650 m were sampled using human occupied vehicles (HOVs) in order to quantify the distribution of CWA, energetics, and select metals. Sites in the same general area, with no munitions within 50 m in any direction were sampled as a control. Sulfur mustard (HD) and its degradation product 1,4-dithiane were detected at each CWA DMM site, as well as a single sample with the HD degradation product 1,4-thioxane. An energetic compound was detected in sediment to a limited extent at one CWA DMM site. Metals common in munitions casings (i.e., Fe, Cu, and Pb) showed similar trends at the regional and site-wide scales, likely reflecting changes in marine sediment deposition and composition. This study shows HD and its degradation products can persist in the deep-marine environment for decades following munitions disposal.

  20. Sedimentological, mineralogical, and geochemical results from surface sediments and the sediment record from Site 2 of the ICDP drilling project at Lake Towuti, Indonesia

    Science.gov (United States)

    Hasberg, A. K.; Melles, M.; Wennrich, V.; Vogel, H.; Just, J.; Russell, J. M.; Bijaksana, S.; Morlock, M.; Opitz, S.

    2017-12-01

    More than 1000 m of sediment core were recovered in spring 2015 from three different drill sites in tropical Lake Towuti (2.5°S, 121°E), Indonesia, during the Towuti Drilling Project (TDP) of the International Continental Scientific Drilling Program (ICDP). Furthermore, a set of 84 lake surface sediment samples, distributed over the entire lake, was collected in order to better understand modern sedimentary processes. The surface samples were investigated for physical, chemical, mineralogical, and biological properties at the University of Cologne (UoC), Germany. On the sediment cores macro- and microscopical lithological descriptions, line-scan imaging, logging of physical properties (MSCL), and subsampling was conducted at the National Lacustrine Core Facility of the University of Minnesota, USA, in November 2015 and January 2016. Afterwards, the archive core halves and 672 subsamples of TDP Site 2 were shipped to the UoC for X-Ray Fluorescence (XRF) scanning and sedimentological, geochemical, and mineralogical analyses, respectively, supplemented by visible to near-infrared spectroscopy (VNIR) at Brown University, USA. The data from the surface samples evidence that allochthonous sedimentation in Lake Towuti today is dominated by fluvial supply from five distinguishable source areas: (i) the Mahalona River to the north, which drains lakes Mahalona and Matano, (ii) inlets around the village of Timampu to the northwest, (iii) the Loeha River to the east, (iv) the Lengke River to the south, and (v) the Lemo-Lemo River to the northeast of Lake Towuti. Of these, source areas (ii) and (iii) as well as (iv) and (v) have similar geochemical compositions, respectively. In addition, the lake sedimentation is significantly influenced by gravitational sediment supply from steep slopes as well as lake-internal gravitational and density-driven processes. The uppermost 41 m of sediment core 2A consist of pelagic sediments (totaling 11 m) and event layers from mass movement

  1. Characterization of Sediments from the Soil Desiccation Pilot Test (SDPT) Site in the BC Cribs and Trenches Area

    Energy Technology Data Exchange (ETDEWEB)

    Um, Wooyong; Truex, Michael J.; Valenta, Michelle M.; Iovin, Cristian; Kutnyakov, Igor V.; Chang, Hyun-shik; Clayton, Ray E.; Serne, R. Jeffrey; Ward, Anderson L.; Brown, Christopher F.; Geiszler, Keith N.; Clayton, Eric T.; Baum, Steven R.; Smith, David M.

    2009-09-25

    This technical report documents the results of laboratory geochemical and hydrologic measurements of sediments collected from new borehole 299-E13-65 (C7047) and comparison of the results with those of nearby borehole 299-13E-62 (C5923) both drilled in the BC Cribs and Trenches Area. The total and water-leachable concentrations of key contaminants will be used to update contaminant-distribution conceptual models and to provide more data for improving baseline risk predictions and remedial alternative selections. Improved understanding of subsurface conditions and methods to remediate these principal contaminants can be also used to evaluate the application of specific technologies to other contaminants across the Hanford Site.

  2. Redox Conditions and Related Color Change in Eastern Equatorial Pacific Sediments: IODP Site U1334

    Science.gov (United States)

    Kordesch, W. E.; Gussone, N. C.; Hathorne, E. C.; Kimoto, K.; Delaney, M. L.

    2011-12-01

    This study was prompted by a 65 m thick brown-green color change in deep-sea sediments of IODP Site U1334 (0-38 Ma, 4799 m water depth) that corresponds to its equatorial crossing (caused by the Northward movement of the pacific plate). Green sediment is a visual indicator of reducing conditions in sediment due to enhanced organic matter deposition and burial. Here we use geochemical redox indicators to characterize the effect of equatorial upwelling on bottom water. The modern redox signal is captured in porewater profiles (nitrate, manganese, iron, sulfate) while trace metal Enrichment Factors (EF) in bulk sediment (manganese, uranium, molybdenum, rhenium) normalized to the detrital component (titanium) record redox state at burial. To measure export productivity we also measure biogenic barium. Porewater profiles reveal suboxic diagenesis; profiles follow the expected sequence of nitrate, manganese oxide, and iron oxide reduction with increasing depth. Constant sulfate (~28 μM) implies anoxia has not occurred. Bulk sediment Mn EF are enriched (EF > 1) throughout the record (Mn EF = 15-200) while U and Mo enrichment corresponds to green color and equatorial proximity (U EF = 4-19; Mo EF = 0-7). Constant Mn enrichment implies continuous oxygenation. Uranium and Mo enrichment near the equator represents suboxic conditions also seen in the porewater. Low Re concentrations (below detection) provide additional evidence against anoxia. A comparison of Mn EF from total digestions to samples treated with an additional reductive cleaning step distinguishes between Mn-oxides and Mn-carbonates, indicating oxygenated and reducing conditions respectively. Mn-carbonate occurrence agrees with U and Mo EF; conditions were more reducing near the equator. Bio-Ba shows significant variability over this interval (22-99 mmol g-1). Our geochemical results indicate that bottom waters became suboxic at the equator as a result of equatorial upwelling-influenced increases in organic

  3. Toxicity and bioaccumulation of sediment-associated contaminants using freshwater invertebrates: A review of methods and applications

    Science.gov (United States)

    Ingersoll, C.G.; Ankley, G.T.; Benoit, D.A.; Brunson, E.L.; Burton, G.A.; Dwyer, F.J.; Hoke, R.A.; Landrum, P.F.; Norberg-King, T. J.; Winger, P.V.

    1995-01-01

    This paper reviews recent developments in methods for evaluating the toxicity and bioaccumulation of contaminants associated with freshwater sediments and summarizes example case studies demonstrating the application of these methods. Over the past decade, research has emphasized development of more specific testing procedures for conducting 10-d toxicity tests with the amphipod Hyalella azteca and the midge Chironomus tentans. Toxicity endpoints measured in these tests are survival for H. azteca and survival and growth for C. tentans. Guidance has also been developed for conducting 28-d bioaccumulation tests with the oligochaete Lumbriculus variegatus, including determination of bioaccumulation kinetics for different compound classes. These methods have been applied to a variety of sediments to address issues ranging from site assessments to bioavailability of organic and inorganic contaminants using field-collected and laboratory-spiked samples. Survival and growth of controls routinely meet or exceed test acceptability criteria. Results of laboratory bioaccumulation studies with L. variegatus have been confirmed with comparisons to residues (PCBs, PAHs, DDT) present from synoptically collected field populations of oligochaetes. Additional method development is currently underway to develop chronic toxicity tests and to provide additional data-confirming responses observed in laboratory sediment tests with natural benthic populations.

  4. Effects of hydrologic connectivity and land use on floodplain sediment accumulation at the Savannah River Site, South Carolina.

    Energy Technology Data Exchange (ETDEWEB)

    Eddy, Jeremy Edward [Univ. of Kentucky, Lexington, KY (United States)

    2017-12-28

    Floodplains, and the sediment accumulating naturally on them,are important to maintain stream water quality and serve as sinks for organic and inorganic carbon. Newer theories contend that land use and hydrologic connectivity (water-mediated transport of matter, energy, and/or organisms within or between elements of the hydrologic cycle) play important roles in determining sediment accumulation on floodplains. This study hypothesizes that changes in hydrologic connectivity have a greater impact on floodplain sediment accumulation than changes in land use. Nine sediment cores from seven sub-basins were collected from the Savannah River Site (SRS), South Carolina, and processed for grain-size, radionuclide dating (7Be, 137Cs, 210Pb), particulate organic carbon (POC), and microscopy. Historical records, including aerial and satellite imagery,were used to identify anthropogenic disturbances in the sub-basins, as well as to calculate the percentages of natural vegetation land cover at the SRS in 1951, and 2014. LiDAR and field survey data identified 251 flow impediments, measured elevation, and recorded standard stream characteristics (e.g., bank height) that canaffect hydrologic connectivity. Radionuclide dating was used to calculate sediment mass accumulation rates (MARs) and linear accumulation rates (LARs) for each core. Results indicate that sedimentation rates have increased across all SRS sub-basins over the past 40-50 years, shortly after site restoration and recovery efforts began.Findings show that hydrologic connectivity proxies (i.e., stream characteristics and impediments) have stronger relationships to MARs and LARs than the land use proxy (i.e., vegetation cover), confirming the hypothesis. Asstream channel depth and the number of impediments increase,floodplain sedimentation rates also increase. This knowledge can help future stream restoration efforts by focusing resources to more efficiently attain stated goals, particularly in terms of floodplain

  5. Transport and fate of viruses in sediment and stormwater from a Managed Aquifer Recharge site

    Science.gov (United States)

    Sasidharan, Salini; Bradford, Scott A.; Šimůnek, Jiří; Torkzaban, Saeed; Vanderzalm, Joanne

    2017-12-01

    Enteric viruses are one of the major concerns in water reclamation and reuse at Managed Aquifer Recharge (MAR) sites. In this study, the transport and fate of bacteriophages MS2, PRD1, and ΦX174 were studied in sediment and stormwater (SW) collected from a MAR site in Parafield, Australia. Column experiments were conducted using SW, stormwater in equilibrium with the aquifer sediment (EQ-SW), and two pore-water velocities (1 and 5 m day-1) to encompass expected behavior at the MAR site. The aquifer sediment removed >92.3% of these viruses under all of the considered MAR conditions. However, much greater virus removal (4.6 logs) occurred at the lower pore-water velocity and in EQ-SW that had a higher ionic strength and Ca2+ concentration. Virus removal was greatest for MS2, followed by PRD1, and then ΦX174 for a given physicochemical condition. The vast majority of the attached viruses were irreversibly attached or inactivated on the solid phase, and injection of Milli-Q water or beef extract at pH = 10 only mobilized a small fraction of attached viruses ( μs > kdet > μl, and katt was several orders of magnitude greater than μl. Therefore, current microbial risk assessment methods in the MAR guideline may be overly conservative in some instances. Interestingly, virus BTCs exhibited blocking behavior and the calculated solid surface area that contributed to the attachment was very small. Additional research is therefore warranted to study the potential influence of blocking on virus transport and potential implications for MAR guidelines.

  6. Occurrence of Pesticides in Water, Sediment, and Soil from the Yolo Bypass, California

    Directory of Open Access Journals (Sweden)

    Kelly L. Smalling

    2007-02-01

    Full Text Available The objective of this study was to evaluate the potential sources of pesticides to the Yolo Bypass, including those that could potentially impact critical life stages of resident fish. To assess direct inputs during inundation, pesticide concentrations were analyzed in water and suspended and bed sediment samples collected from source watersheds during high-flow events. To understand inputs from direct application on fields, pesticides were also measured in soils collected from several sites within the Bypass. Thirteen current-use pesticides were detected in water samples collected in 2004 with the highest pesticide concentrations observed at the input sites to the Bypass during high-flow. Hexazinone and simazine were detected at all sites and at some of the highest concentrations. In bed and suspended sediments collected in 2004 and 2005, thirteen current-use pesticides were detected along with DDT and its metabolites. Trifluralin, DDE, and DDT were highest in the bed sediments, whereas oxyfluorfen and thiobencarb were highest in the suspended sediments. With the exception of the three organochlorine insecticides, suspended sediments had higher pesticide concentrations compared to bed sediments, indicating the potential for pesticide transport especially during high-flow events. Soil samples were dominated by DDT and its degradates but also contained a variety of current-use pesticides typically at lower concentrations. The types of pesticides detected in water and sediments were correlated with agricultural application in each watershed. Understanding the distribution of pesticides between the water and sediment is important in assessing their fate and transport within the Bypass, and in evaluating the exposure and potential effects to resident fish.

  7. Prediction of organic combined sewer sediment release and transport

    OpenAIRE

    Seco, Raquel Irene; Schellart, Alma Neeltje Antonia; Gómez Valentín, Manuel; Tait, Simon

    2018-01-01

    Accurate predictions of sediment loads released by sewer overflow discharges are important for being able to provide protection to vulnerable receiving waters. These predictions are sensitive to the estimated sediment characteristics and on the site conditions of in-pipe deposit formation. Their application without a detailed analysis and understanding of the initial conditions under which in-sewer deposits were formed normally results in very poor estimations. In this study, in-sewer sedimen...

  8. Effects of fine sediment, hyporheic flow, and spawning site characteristics on survival and development of bull trout embryos

    Science.gov (United States)

    Bowerman, Tracy; Neilson, Bethany; Budy, Phaedra

    2014-01-01

    Successful spawning is imperative for the persistence of salmonid populations, but relatively little research has been conducted to evaluate factors affecting early life-stage survival for bull trout (Salvelinus confluentus), a threatened char. We conducted a field experiment to assess the relationship between site-specific environmental factors and bull trout embryo survival and fry emergence timing. Survival from egg to hatch was negatively related to percent fine sediment (construction and selection of spawning sites with strong downwelling appear to enhance hyporheic flow rates and bull trout egg survival, but early life-stage success may ultimately be limited by intrusion of fine sediment into the incubation environment.

  9. A gel probe equilibrium sampler for measuring arsenic porewater profiles and sorption gradients in sediments: II. Field application to Haiwee reservoir sediment

    Science.gov (United States)

    Campbell, K.M.; Root, R.; O'Day, P. A.; Hering, J.G.

    2008-01-01

    Arsenic (As) geochemistry and sorption behavior were measured in As- and iron (Fe)-rich sediments of Haiwee Reservoir by deploying undoped (clear) polyacrylamide gels and hydrous ferric oxide (HFO)-doped gels in a gel probe equilibrium sampler, which is a novel technique for directly measuring the effects of porewater composition on As adsorption to Fe oxides phases in situ. Arsenic is deposited at the sediment surface as As(V) and is reduced to As(III) in the upper layers of the sediment (0-8 cm), but the reduction of As(V) does not cause mobilization into the porewater. Dissolved As and Fe concentrations increased at depth in the sediment column driven by the reductive dissolution of amorphous Fe(III) oxyhydroxides and conversion to a mixed Fe(II, III) green rust-type phase. Adsorption of As and phosphorous (P) onto HFO-doped gels was inhibited at intermediate depths (10-20 cm), possibly due to dissolved organic or inorganic carbon, indicating that dissolved As concentrations were at least partially controlled by porewater composition rather than surface site availability. In sediments that had been recently exposed to air, the region of sorption inhibition was not observed, suggesting that prior exposure to air affected the extent of reductive dissolution, porewater chemistry, and As adsorption behavior. Arsenic adsorption onto the HFO-doped gels increased at depths >20 cm, and the extent of adsorption was most likely controlled by the competitive effects of dissolved phosphate. Sediment As adsorption capacity appeared to be controlled by changes in porewater composition and competitive effects at shallower depths, and by reductive dissolution and availability of sorption sites at greater burial depths. ?? 2008 American Chemical Society.

  10. Long-term Measurement of Sediment Resuspension and Gas Hydrate Stability at a Gulf of Mexico Seep Site

    Science.gov (United States)

    Vardaro, M. F.; Bender, L. C.; MacDonald, I. R.

    2003-12-01

    To study the temporal topographic and hydrologic changes in Gulf of Mexico cold seeps, we deployed a deep-sea time-lapse camera, several temperature probes and an ADCP mooring at the continental shelf seep community surrounding a gas hydrate outcropping. The digital camera recorded one still image every six hours for three months in 2001, every two hours for the month of June 2002 and every six hours for the month of July 2002. A pair of 300 kHz Workhorse acoustic Doppler current profilers (ADCPs) attached to a 540 meter-long mooring were anchored approximately 2 km from the site in 2002. Temperature probes were deployed at the site over the entire experimental period. The data recovered provide a comprehensive record of gas hydrate mound processes. We calculated biological activity by identifying fauna observed in the time-lapse record and recording the number of individuals and species seen in each image. 1,381 individual organisms representing over 20 species were observed. An average of 4.6 (+/-3.0) organisms were seen in each frame during the three-month deployment, while 3.6 (+/-4.2) were seen per frame in the one-month deployment. An extensive amount of sediment suspension and redistribution occurred during the deployment period. By digitally analyzing the luminosity of the water column above the mound and plotting the results over time the turbidity at the site could be quantified. A 24.1-hour diurnal pattern can be seen in the record, indicating a possible tidal or inertial component to deep-sea currents in this area. Contrary to expectations, there was no major change in shape or size of the gas hydrate outcrop being studied. This indicates a higher degree of stability than laboratory studies or prior in situ observations have shown. The stable topography of the gas hydrate mound combines with high organic output and sediment turnover to serve as a focus of benthic predatory activity. The frequency and recurrence of sediment resuspension indicate that

  11. Leaching tendencies of uranium and regulated trace metals from the Hanford Site 300 Area North Process Pond sediments

    International Nuclear Information System (INIS)

    Serne, R.J.; LeGore, V.L.; Mattigod, S.V.

    1994-09-01

    Data are presented that address the leaching tendencies and the total chemical composition of metals in feed materials and soil-washed fines generated by Alternative Remediation Technology, Inc. during a pilot-scale soil physical separation test performed at the 300 Area North Process Pond (Facility 316-2) on the Hanford Site in the spring of 1994. Four 300 Area North Process Pond sediments and one sediment from outside the pond's fenced area were leach-tested using the Toxicity Characteristic Leach Procedure (TCLP) and other modified US Environmental Protection Agency and American Society for Testing and Materials protocols. Finally, leachate from the most contaminated sediment was used to load the Hanford sediment obtained outside the facility to evaluate the potential for contaminant adsorption onto natural sediments. The sediment characterization, leach, and adsorption results will be used in the evaluation of remedial alternatives in the 300-FF-1 Operable Unit Remedial Investigation/Feasibility Study

  12. Sediment characteristics of the 2800 meter Atlantic nuclear waste disposal site: Radionuclide retention potential

    Energy Technology Data Exchange (ETDEWEB)

    Neiheisel, James

    1979-09-01

    coast funnel sediment into the Hudson Canyon and turbidity currents transport sediment down the submarine canyon; some of this sediment is advected in a southwesterly direction from the submarine canyon by contour currents for deposition along the continental rise. The net deposition at the waste site thus consists of the 'rain' of biogenous microorganisms, the transport of sediment from the coastal and continental shelf area by turbidity currents via submarine canyons, and transport of sediment along the continental rise by prevailing contour currents. The effectiveness of the sediment barrier relates to timely burial of the waste drum prior to leachate release from ruptured or corroded drums as well as freedom from 'short circuiting' effects such as bioturbation or other mechanisms capable of providing migration pathways for the radionuclides. (author)

  13. Supplementary guidance for the investigation and risk-assessment of potentially contaminated sediments

    Energy Technology Data Exchange (ETDEWEB)

    Baker, K.; Spadaro, P.; Starr, J.; Thomas, J. [Arcadis, Arnhem (Netherlands); Hildenbrand, B. [Energy Institute, London (United Kingdom); Smith, J.W.N.; Dunk, M.; Grosjean, T.; De Ibarra, M.; Medve, A.; Den Haan, K.

    2013-11-15

    This report provides guidance on the investigation and assessment of potentially contaminated sediments, focusing on the inland, estuarine and coastal environments. It is designed as a complementary, technical companion document to Energy Institute and CONCAWE (2013) report 'Guidance on characterising, assessing and managing risks associated with potentially contaminated sediments' (Report E1001). It highlights a number of significant challenges associated with assessing the aquatic and water bottom environment, which means that a sediment assessment should not be undertaken lightly. Where a decision is taken to undertake a site assessment, this report promotes the use of an iterative process of Conceptual Site Model (CSM) development, data collection, data evaluation and a continuous CSM refinement, taking into account the results obtained. Risk-based assessment is described throughout the report, entailing four tiers of assessment, which progress from a qualitative assessment (Tier 0) through to a detailed cause-attribution assessment (Tier 3), in which the decrease in uncertainty in the assessment process is balanced against the increased costs and timescales with progress to a higher tier assessment. The application of this evidence-driven risk-based approach to sediment site management, including remedial control measures, should help to overcome at least some of the challenges associated with contaminants in sediment sites in Europe, and promote a sustainable approach to sediment management on a case-by-case basis.

  14. Survey of Potential Hanford Site Contaminants in the Upper Sediment for the Reservoirs at McNary, John Day, The Dalles, and Bonneville Dams, 2003

    Energy Technology Data Exchange (ETDEWEB)

    Patton, Gregory W.; Priddy, M; Yokel, Jerel W.; Delistraty, Damon A.; Stoops, Thomas M.

    2005-02-01

    This report presents the results from a multi-agency cooperative environmental surveillance study. of the study looked at sediment from the pools upstream from dams on the Columbia River that are downstream from Hanford Site operations. The radiological and chemical conditions existing in the upper-level sediment found in the pools upstream from McNary Dam, John Day Dam, The Dalles Lock and Dam, and Bonneville Dam were evaluated. This study also evaluated beach sediment where available. Water samples were collected at McNary Dam to further evaluate potential Hanford contaminants in the lower Columbia River. Samples were analyzed for radionuclides, chemicals, and physical parameters. Results from this study were compared to background values from sediment and water samples collect from the pool upstream of Priest Rapids Dam (upstream of the Hanford Site) by the Hanford Site Surface Environmental Surveillance Project.

  15. TBT and its metabolites in sediments: Survey at a German coastal site and the central Baltic Sea.

    Science.gov (United States)

    Abraham, Marion; Westphal, Lina; Hand, Ines; Lerz, Astrid; Jeschek, Jenny; Bunke, Dennis; Leipe, Thomas; Schulz-Bull, Detlef

    2017-08-15

    Since the 1950s the organotin compound tributyltin (TBT) was intensively used in antifouling paints for marine vessels and it became of concern for the marine environment. Herein, we report on a study from 2015 on TBT and its metabolites monobutyltin (MBT) and dibutyltin (DBT) in sediments from the central Baltic Sea and a Baltic Sea coastal site with strong harbor activities (Warnemünde). Sublayers from a sediment core from the Arkona Basin were analyzed to investigate the long term organotin pressure for the Baltic Sea. For the central Baltic Sea total organotin (MBT+DBT+TBT) ranged from 100 to 500ng/g TOC with distinct areas of high organotin content probably due to historical inputs. For the coastal site total organotin ranged from 10,000 to 60,000ng/g TOC. MBT and DBT were the predominant organotin species detected. Overall, the data obtained indicate the progress of TBT degradation at the investigated sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Characterizing riverbed sediment using high-frequency acoustics 2: scattering signatures of Colorado River bed sediment in Marble and Grand Canyons

    Science.gov (United States)

    Buscombe, Daniel D.; Grams, Paul E.; Kaplinski, Matt A.

    2014-01-01

    In this, the second of a pair of papers on the statistical signatures of riverbed sediment in high-frequency acoustic backscatter, spatially explicit maps of the stochastic geometries (length- and amplitude-scales) of backscatter are related to patches of riverbed surfaces composed of known sediment types, as determined by geo-referenced underwater video observations. Statistics of backscatter magnitudes alone are found to be poor discriminators between sediment types. However, the variance of the power spectrum, and the intercept and slope from a power-law spectral form (termed the spectral strength and exponent, respectively) successfully discriminate between sediment types. A decision-tree approach was able to classify spatially heterogeneous patches of homogeneous sands, gravels (and sand-gravel mixtures), and cobbles/boulders with 95, 88, and 91% accuracy, respectively. Application to sites outside the calibration, and surveys made at calibration sites at different times, were plausible based on observations from underwater video. Analysis of decision trees built with different training data sets suggested that the spectral exponent was consistently the most important variable in the classification. In the absence of theory concerning how spatially variable sediment surfaces scatter high-frequency sound, the primary advantage of this data-driven approach to classify bed sediment over alternatives is that spectral methods have well understood properties and make no assumptions about the distributional form of the fluctuating component of backscatter over small spatial scales.

  17. Polychlorinated biphenyls in sediments of selected sites of the Moroccan coastal zone

    Energy Technology Data Exchange (ETDEWEB)

    Piazza, R.; Ferrari, S.; Moret, I.; Gambaro, A. [Univ. Ca Foscari, Venezia (Italy). Dept. of Environmental Sciences; Le Moumni, B. [Univ. Abdelmaleck Essaadi, Tangier (Morocco). Dept. of Earth Sciences and Oceanology; Bellucci, L.G.; Frignani, M. [ISMAR-CNR, Sezione di Geologia Marina, Bologna (Italy); Zangrando, R. [IDPA-CNR, Venezia (Italy)

    2004-09-15

    A good knowledge of sources of contaminants, distribution mechanisms, sites where chemicals tend to accumulate, potential risk and actual danger to the human and environmental health is fundamental to design a policy for the environment. In this respect, it is important to recognize that sediments can keep a record of the conditions of the environment at the time of their deposition and accumulation and hence can be used to reconstruct history and trends of contamination processes. Furthermore, actively accreting salt marshes, due to the lack of sediment reworking, may provide a relatively high resolution record of atmospheric fluxes. On the other hand, transition coastal environments are of particular importance because of their position between the inland sources and the sea, which is the final repository of all the materials mobilized from the continent. In order to assess the level of PCB contamination in key areas of coastal Morocco we chose to analyse sediments from the Nador (NAD) and the Moulay Bousselham (MB) lagoons, the terminal tract of the Martil River (MR), the port of Tangier (TG) and a soil taken close to the industrial town of Tetouan (TS). The first two were chosen because of their high environmental value, the others as representative of zones potentially contaminated.

  18. Application of Binary Diagnostic Ratios of Polycyclic Aromatic Hydrocarbons for Identification of Tsunami 2004 Backwash Sediments in Khao Lak, Thailand

    Directory of Open Access Journals (Sweden)

    Siwatt Pongpiachan

    2014-01-01

    Full Text Available Identification of Tsunami deposits has long been a controversial issue among geologists. Although there are many identification criteria based on the sedimentary characteristics of unequivocal Tsunami deposits, the concept still remains ambiguous. Apart from relying on some conventional geological, sedimentological, and geoscientific records, geologists need some alternative “proxies” to identify the existence of Tsunami backwash in core sediments. Polycyclic aromatic hydrocarbons (PAHs are a class of very stable organic molecules, which can usually be presented as complex mixtures of several hundred congeners; one can assume that the “Tsunami backwash deposits” possess different fingerprints of PAHs apart from those of “typical marine sediments.” In this study, three-dimensional plots of PAH binary ratios successfully identify the Tsunami backwash deposits in comparison with those of global marine sediments. The applications of binary ratios of PAHs coupled with HCA are the basis for developing site-specific Tsunami deposit identification criteria that can be applied in paleotsunami deposits investigations.

  19. Hydrogeologic framework, arsenic distribution, and groundwater geochemistry of the glacial-sediment aquifer at the Auburn Road landfill superfund site, Londonderry, New Hampshire

    Science.gov (United States)

    Degnan, James R.; Harte, Philip T.

    2013-01-01

    Leachate continues to be generated from landfills at the Auburn Road Landfill Superfund Site in Londonderry, New Hampshire. Impermeable caps on the three landfills at the site inhibit direct infiltration of precipitation; however, high water-table conditions allow groundwater to interact with landfill materials from below, creating leachate and ultimately reducing conditions in downgradient groundwater. Reducing conditions can facilitate arsenic transport by allowing it to stay in solution or by liberating arsenic adsorbed to surfaces and from geologic sources, such as glacial sediments and bedrock. The site occupies a 180-acre parcel of land containing streams, ponds, wetlands, and former gravel pits located in glacial sediment. Four areas, totaling 14 acres, including three landfills and one septage lagoon, were used for waste disposal. The site was closed in 1980 after volatile organic compounds associated with industrial waste dumping were detected. The site was added to the U.S. Environmental Protection Agency National Priority List in 1982, and the landfills were capped in 1996. Although volatile organic compound concentrations in groundwater have declined substantially, some measurable concentrations remain. Temporally variable and persistent elevated arsenic concentrations have been measured in groundwater affected by the landfill leachate. Microbial consumption of carbon found in leachate is a driver of reducing conditions that liberate arsenic at the site. In addition to sources of carbon in landfill leachate, wetland areas throughout the site also could contribute carbon to groundwater, but it is currently unknown if any of the wetland areas have downward or reversing gradients that could allow the infiltration of surface water to groundwater. Red-stained sediments and water indicate iron-rich groundwater discharge to surface water and are also associated with elevated concentrations of arsenic in sediment and groundwater. Ironrich groundwater seeps have

  20. Sedimentation

    Science.gov (United States)

    Cliff R. Hupp; Michael R. Schening

    2000-01-01

    Sedimentation is arguably the most important water-quality concern in the United States. Sediment trapping is cited frequently as a major function of riverine-forested wetlands, yet little is known about sedimcntation rates at the landscape scale in relation to site parameters, including woody vegetation type, elevation, velocity, and hydraulic connection to the river...

  1. Geomorphological condition and sea bottom sediment characteristics of Sebagin coast for NPP site evaluation in South Bangka

    International Nuclear Information System (INIS)

    Yuliastuti; Heni Susiati; Yarianto Sugeng Budi Susilo

    2015-01-01

    Study on geomorphological condition and sea bottom sediment in the coastal area of Sebagin, South Bangka Regency, Bangka Belitung Province has been performed. Geomorphological of the seabed was valuable to identify geological structures that exist on the seabed layers. Whereas, sediments seabed characteristics was useful to provide portrait of seabed layer due to the stability of NPP site concerning the seismic aspect and the determination of water intake position. The objective of the study was to evaluate geomorphological condition and sea bed sediment characteristics in the South Bangka sea. Methodology used for evaluating geomorphological of the sea bed were Multi Beam Echo Sounder (MBES) and Single Beam Echo Sounder (SBES), while for sea bottom sediment characteristics, high resolution seismic reflection using SBP together with sediment sample analysis were used. The result of the study showed that the study area was a shallow water sea with a depth range of 1-59 m. Geomorphological profile of the sea bed tend to be irregular and based on the seismic interpretation, there were no fault exists. Result analysis on the sea bottom sediment showed that clay distribution dominated the study area. (author)

  2. Input-variable sensitivity assessment for sediment transport relations

    Science.gov (United States)

    Fernández, Roberto; Garcia, Marcelo H.

    2017-09-01

    A methodology to assess input-variable sensitivity for sediment transport relations is presented. The Mean Value First Order Second Moment Method (MVFOSM) is applied to two bed load transport equations showing that it may be used to rank all input variables in terms of how their specific variance affects the overall variance of the sediment transport estimation. In sites where data are scarce or nonexistent, the results obtained may be used to (i) determine what variables would have the largest impact when estimating sediment loads in the absence of field observations and (ii) design field campaigns to specifically measure those variables for which a given transport equation is most sensitive; in sites where data are readily available, the results would allow quantifying the effect that the variance associated with each input variable has on the variance of the sediment transport estimates. An application of the method to two transport relations using data from a tropical mountain river in Costa Rica is implemented to exemplify the potential of the method in places where input data are limited. Results are compared against Monte Carlo simulations to assess the reliability of the method and validate its results. For both of the sediment transport relations used in the sensitivity analysis, accurate knowledge of sediment size was found to have more impact on sediment transport predictions than precise knowledge of other input variables such as channel slope and flow discharge.

  3. Pocatello 10 x 20 NTMS area Idaho. Data report: National Uranium Resource Evaluation program, hydrogeochemical and stream sediment reconnaissance

    International Nuclear Information System (INIS)

    Cook, J.R.

    1980-07-01

    This data report presents results of groundwater and stream/surface sediment reconnaissance in the National Topographic Map Series (NTMS) Pocatello 1 0 x 2 0 quadrangle. Surface samples (sediment) were collected from 1701 sites. The target sampling density was one site per 16 square kilometers (six square miles). Ground water samples were collected at 381 sites. Neutron activation analysis (NAA) results are given for uranium and 16 other elements in sediments, and for uranium and 9 other elements in ground water. Mass spectrometry results are given for helium in ground water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Statistical summaries of data and a brief description of results are given. A generalized geologic map and a summary of the geology of the area are included. Data from sediment sites include: (1) stream water chemistry measurements where applicable (pH, conductivity, and alkalinity); and (2) elemental analyses for sediment samples (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Sample site descriptors (stream characteristics, vegetation, etc.) are also tabulated. Areal distribution maps, histograms, and cumulative frequency plots for most elements; U/Th, U/Hf, and U/La ratios; and scintillometer readings for sediment sample sites are included on the microfiche. Data from groundwater sites include: (1) water chemistry measurements (pH, conductivity, and alkalinity); (2) physical measurements where applicable (water temperature, well description, and scintillometer reading); and (3) elemental analyses (U, Al, Br, Cl, Dy, F, He, Mg, Mn, Na, and V). Data from stream water sites include: (1) water chemistry measurements (pH, conductivity, and alkalinity); and (2) elemental analyses

  4. Sedimentation rates in eastern North America reveal strong links between regional climate, depositional environments, and sediment accumulation

    Science.gov (United States)

    Goring, S. J.; McLachlan, J. S.; Jackson, S. T.; Blaauw, M.; Christen, J.; Marlon, J.; Blois, J.; Williams, J. W.

    2011-12-01

    PalEON is a multidisciplinary project that combines paleo and modern ecological data with state-of-the-art statistical and modelling tools to examine the interactions between climate, fire and vegetation during the past two millennia in the northeastern United States. A fundamental challenge for PalEON (and paleo research more broadly) is to improve age modelling to yield more accurate sediment-core chronologies. To address this challenge, we assessed sedimentation rates and their controls for 218 lakes and mires in the northeastern U.S. Sedimentation rates (yr/cm) were calculated from age-depth models, which were obtained from the Neotoma database (www.neotomadb.org) and other contributed pollen records. The age models were recalibrated to IntCal09 and augmented in some cases using biostratigraphic markers (Picea decline, 16 kcal BP - 10.5 kcal BP; Quercus rise, 12 - 9.1 kcal BP; and Alnus decline, 11.5 - 10.6 kcal BP) as described in Blois et al. (2011). Relationships between sedimentation rates and sediment age, site longitude, and depositional environment (lacustrine or mire) are significant but weak. There are clear and significant links between variations in the NGRIP record of δ18O and sedimentation in mires across the PalEON region, but no links to lacustrine sedimentation rates. This result indicates that super-regional climatic control of primary productivity, and thus autochthonic sediment deposition, dominates in mires while deposition in lacustrine basins may be driven primarily by local and regional factors including watershed size, surficial materials,and regional vegetation. The shape of the gamma probability functions that best describe sedimentation rate distributions are calculated and presented here for use as priors in Bayesian age modelling applications such as BACON (Blaauw and Christen, in press). Future applications of this research are also discussed.

  5. OU3 sediment dating and sedimentation rates

    International Nuclear Information System (INIS)

    Blair, R.B.; Wolaver, H.A.; Burger, V.M.

    1994-01-01

    Environmental Technologies at Rocky Flats Environmental Technology Site (RFS) investigated the sediment history of Standley Lake, Great Western Reservoir, and Mower Reservoir using 137 Cs and 239,240 Pu global fall-out as dating indicators. These Colorado Front Range reservoirs have been the subject of study by various city, state and national agencies due to suspected Department of Energy Rocky Flats Plant impacts. We performed sediment dating as part of the RCRA Facility Investigation/Remedial Investigation Report for Operable Unit 3. A sediment chronology profile assists scientist in determining the year of sedimentation for a particular peak concentration of contaminants. Radioisotope sediment dating for the three reservoirs indicated sedimentation rates of 0.7 to 0.8 in./yr. for Standley Lake (SL), 0.9 in./yr. for Great Western Reservoir (GWR), and 0.3 in./yr. in Mower Reservoir (MR). RFS sediment dating for Operable Unit 3 compared favorably with the Hardy, Livingston, Burke, and Volchok Standley Lake study. This report describes the cesium/plutonium sediment dating method, estimates sedimentation rates for Operable Unit 3 reservoirs, and compares these results to previous investigations

  6. Multi criteria analysis in environmental management: Selecting the best stormwater erosion and sediment control measure in Malaysian construction sites

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hadu, Ibrahiem Abdul Razak; Sidek, Lariyah Mohd; Desa, Mohamed Nor Mohamed [Civil Engineering, Universiti Tenga Nasional, Kajang, Selangor (Malaysia); Basri, Noor Ezlin Ahmad [Civil and Structural Engineering, Universiti Kebangsaan Malyasia, Bangi, Selangor (Malaysia)

    2011-07-01

    Malaysia located in a tropical region which is interested with a heavy rainfall through the whole seasons of the year. Construction stages usually associated with soil disturbing due to land clearing and grading activities, this combined with the tropical climate in Malaysia, will generate an enormous amount of soil to be eroded and then deposited in the adjacent water bodies. There are many kinds of mitigation measures used so as to reduce the impact of erosion and sedimentation that are generated due to the stormwater in construction sites. This paper presents the application of Multi Criteria Analysis (MCA) tool in choosing the best stormwater control measure by depending on specified criteria and criterion weight. The results obtained from the application of MCA in stormwater pollution control have many benefits to the contractors, consultants and decision makers by making them able to select the best control measure for every stage of construction.

  7. IN SITU REMEDIATION OF CONTAMINATED SEDIMENTS - ACTIVE CAPPING TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Knox, A.; Roberts, J.; Paller, M.; Reible, D.

    2010-09-02

    Active capping is a relatively new approach for treating contaminated sediments. It involves applying chemically reactive amendments to the sediment surface. The main role of active caps is to stabilize contaminants in contaminated sediments, lower the bioavailable pool of contaminants, and reduce the release of contaminants to the water column. Metals are common contaminants in many marine and fresh water environments as a result of industrial and military activities. The mobile, soluble forms of metals are generally considered toxic. Induced chemical precipitation of these metals can shift toxic metals from the aqueous phase to a solid, precipitated phase which is often less bioavailable. This approach can be achieved through application of sequestering agents such as rock phosphates, organoclays, zeolites, clay minerals, and biopolymers (e.g., chitosan) in active capping technology. Active capping holds great potential for a more permanent solution that avoids residual risks resulting from contaminant migration through the cap or breaching of the cap. In addition to identifying superior active capping agents, research is needed to optimize application techniques, application rates, and amendment combinations that maximize sequestration of contaminants. A selected set of active capping treatment technologies has been demonstrated at a few sites, including a field demonstration at the Savannah River Site, Aiken, SC. This demonstration has provided useful information on the effects of sequestering agents on metal immobilization, bioavailability, toxicity, and resistance to mechanical disturbance.

  8. In Situ Remediation Of Contaminated Sediments - Active Capping Technology

    International Nuclear Information System (INIS)

    Knox, A.; Roberts, J.; Paller, M.; Reible, D.

    2010-01-01

    Active capping is a relatively new approach for treating contaminated sediments. It involves applying chemically reactive amendments to the sediment surface. The main role of active caps is to stabilize contaminants in contaminated sediments, lower the bioavailable pool of contaminants, and reduce the release of contaminants to the water column. Metals are common contaminants in many marine and fresh water environments as a result of industrial and military activities. The mobile, soluble forms of metals are generally considered toxic. Induced chemical precipitation of these metals can shift toxic metals from the aqueous phase to a solid, precipitated phase which is often less bioavailable. This approach can be achieved through application of sequestering agents such as rock phosphates, organoclays, zeolites, clay minerals, and biopolymers (e.g., chitosan) in active capping technology. Active capping holds great potential for a more permanent solution that avoids residual risks resulting from contaminant migration through the cap or breaching of the cap. In addition to identifying superior active capping agents, research is needed to optimize application techniques, application rates, and amendment combinations that maximize sequestration of contaminants. A selected set of active capping treatment technologies has been demonstrated at a few sites, including a field demonstration at the Savannah River Site, Aiken, SC. This demonstration has provided useful information on the effects of sequestering agents on metal immobilization, bioavailability, toxicity, and resistance to mechanical disturbance.

  9. Monitoring the impact of urban effluents on mineral contents of water and sediments of four sites of the river Ravi, Lahore.

    Science.gov (United States)

    Shakir, Hafiz Abdullah; Qazi, Javed Iqbal; Chaudhry, Abdul Shakoor

    2013-12-01

    We assessed the impact of urban effluents on the concentrations of selected minerals (Cd, Cr, Cu, Fe, Pb, Zn, Mn, Ni, and Hg) in river Ravi before and after its passage through Lahore city. Water and sediment samples were collected from three lowly to highly polluted downstream sites (Shahdera (B), Sunder (C), and Balloki (D)) alongside the least polluted upstream site (Siphon (A)) during high and low river flow seasons. All the mineral concentrations increased up to site C but stabilized at site D, showing some recovery as compared to the third sampling site. The trend of mean mineral concentration was significantly higher during the low than the high flow season at all the sites. The mean Hg concentrations approached 0.14 and 0.12 mg/l at site A which increased (%) up to 107 and 25% at site B, 1,700 and 1,317% at site C, and 1,185 and 1,177% at site D during low and high river flows, respectively. All mineral concentrations were much higher in the sediment than the water samples. Mean Cd (917%), Cr (461%), Cu (300%), Fe (254%), Pb (179%), Zn (170%), Mn (723%), Ni (853%), and Hg (1,699%) concentrations were higher in riverbed sediments sampled from site C in comparison with the sample collected at site A during low flow season. The domestic and industrial discharges from Lahore city have created undesirable water qualities during the low river flow season. As majority of the mineral levels in the river Ravi were higher than the permissible and safe levels, this is of immediate concern for riverine fish consumers and the users of water for recreation and even irrigation. The use of these waters may pose health risks, and therefore, urgent intervention strategies are needed to minimize river water pollution and its impact on fish-consuming communities of this study area and beyond.

  10. Application of tracer techniques in studies of sediment transport in Vietnam

    International Nuclear Information System (INIS)

    Hai, P.S.; Quang, N.H.; Xuan, N.M.; Chuong, P.N.; Hien, P.Z.

    1997-01-01

    As a consequence of intensive erosion processes typical of the humid tropical one, as well as of human activities destroying tropical forests, grasslands and protective mangrove swamps, etc, most navigable estuaries in Vietnam suffer seriously from sedimentation. In order to maintain the necessary depth for the 7.000 ton vessels entering and leaving ports, a large amount of money is spent annually on dredging operation. A lot of hydraulic and sedimentary surveys were carried out in the past by different groups of researchers. However, owing to the complexity of sediment processes in estuarine areas under the hydrometeorological conditions typical of the southwest Pacific, the use of just any modelling approach is not suitable. In many cases, the conclusions inferred from mathematical models have been the controversial matter. The tracer techniques, which have been employed in the country since 1991, have provided a very efficient tool to obtain a dynamic idea of sediment transport. Many investigations of bedload transport using Sc-46 labelled glass and Ir-192 glass as radioactive tracers were carried out from 1992 to 1996 at Haiphong harbour area. Bedload transport rates under effect of northeast monsoon and southeast monsoon at 5 zones located on both sides of the navigation channel were estimated. In bedload transport studies, apart from conventional methods for assessment of transport thickness, a new method using the ratio of photoelectric peak to Compton region of spectra acquired directly on the sea bed was put forward and applied. The influence of dredging materials at two dumping sites under different tidal phases on in fill rate in the access channel was assessed by radioactive tracers. The qualitative and quantitative information on sediment transport at some experimental sites given by tracers was used by modelling specialists who have undertaken hydraulic and sedimentary surveys in this region

  11. Sorption kinetics of Cs and Sr in sediments of a Savannah River Site reservoir

    International Nuclear Information System (INIS)

    Stephens, J.A.

    1997-07-01

    Laboratory measurements of the sorption and desorption of 134 Cs and 85 Sr to sediments were conducted. These sediments were sampled from the profundal zone of Par Pond at the Savannah River Site, Aiken, South Carolina. The isotopes 134 Cs and 85 Sr were used to trace the sorption properties of the main contaminants found in the reservoir which are 137 Cs and 90 Sr respectively. The sorption behavior of these two elements was studied using spiked sediment/water slurries of a known mass to volume ratio. The results reveal that Sr undergoes significant reversible sorption while a fraction of Cs irreversibly sorbs to the sediment. The calculated distribution coefficient Kd at equilibrium was (3 ± 0.6) x 10 3 for 134 Cs after 60 d and (1 ± 0.2) x 10 3 for 85 Sr after 7 d at pH ∼ 6 and slurry ratio of 1:1000 g/ml. The K d for 134 Cs ranged from 2 x 10 2 to 3 x 10 4 depending on pH and conductivity. The 85 Sr reached equilibrium in a few days, while 134 Cs reached an apparent equilibrium in 1--2 months. The K d for 134 Cs was a function of the slurry ratio, pH, conductivity, and contact time. These factors were interrelated since the sediments released ions to the slurry mixture which decreased the pH and increased the conductivity. A sorption isotherm measured for 134 Cs was linear at water concentrations from 60 mBq/ml to 20 Bq/ml. A kinetic model was proposed to describe the basic sorption of 134 Cs to Par Pond sediments under homogeneous laboratory conditions

  12. Chronology of the cave interior sediments at Gran Dolina archaeological site, Atapuerca (Spain)

    Science.gov (United States)

    Parés, J. M.; Álvarez, C.; Sier, M.; Moreno, D.; Duval, M.; Woodhead, J. D.; Ortega, A. I.; Campaña, I.; Rosell, J.; Bermúdez de Castro, J. M.; Carbonell, E.

    2018-04-01

    The so-called "Gran Dolina site" (Atapuerca mountain range, N Spain) is a karstic cavity filled by sediments during the Pleistocene, some of which contain a rich ensemble of archaeological and paleontological records. These sediments have contributed significantly to our understanding of early human dispersal in Europe but, in contrast, older, interior facies deposits have received much less of attention. The stratigraphy of Gran Dolina reveals an abrupt sedimentary change of interior to entrance facies from bottom to top, reflecting a significant paleoenvironmental change that promoted the accumulation of sediments transported from the vicinity of the cave by water or "en masse". Since the major magnetic polarity reversal known as the Matuyama-Brunhes boundary (0.78 Ma) was detected within the TD7 unit in the middle of the stratigraphic section, we carried out a new combined paleomagnetic, radiometric (U-Pb), and electron spin resonance (ESR) dating study of the lower part of the sequence in order to constrain the chronology of the interior facies at Gran Dolina. U-Pb analysis of speleothems did not produce age information as the samples proved to be extremely unradiogenic. The magnetic stratigraphy of the cave interior sediments reveals a dominant reverse magnetic polarity, coherent with a Matuyama age, and interrupted by a normal polarity magnetozone interpreted as the Jaramillo Subchron (1.0-1.1 Ma). ESR ages on quartz grains from the upper part of the interior facies sediments are coherent with such an interpretation. We conclude that the fluvial deposits (interior facies) that constitute the cave floor began accumulating before 1.2 Ma. The development of large cave entrances at Gran Dolina occurred shortly after the Jaramillo Subchron but before ca 900 ka ago.

  13. Application of Crunch-Flow Routines to Constrain Present and Past Carbon Fluxes at Gas-Hydrate Bearing Sites

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Marta [Oregon State Univ., Corvallis, OR (United States). College of Earth, Ocean, and Atmospheric Sciences

    2014-01-31

    In November 2012, Oregon State University initiated the project entitled: Application of Crunch-Flow routines to constrain present and past carbon fluxes at gas-hydrate bearing sites. Within this project we developed Crunch-Flow based modeling modules that include important biogeochemical processes that need to be considered in gas hydrate environments. Our modules were applied to quantify carbon cycling in present and past systems, using data collected during several DOE-supported drilling expeditions, which include the Cascadia margin in US, Ulleung Basin in South Korea, and several sites drilled offshore India on the Bay of Bengal and Andaman Sea. Specifically, we completed modeling efforts that: 1) Reproduce the compositional and isotopic profiles observed at the eight drilled sites in the Ulleung Basin that constrain and contrast the carbon cycling pathways at chimney (high methane flux) and non-chimney sites (low methane, advective systems); 2) Simulate the Ba record in the sediments to quantify the past dynamics of methane flux in the southern Hydrate Ridge, Cascadia margin; and 3) Provide quantitative estimates of the thickness of individual mass transport deposits (MTDs), time elapsed after the MTD event, rate of sulfate reduction in the MTD, and time required to reach a new steady state at several sites drilled in the Krishna-Godavari (K-G) Basin off India. In addition we developed a hybrid model scheme by coupling a home-made MATLAB code with CrunchFlow to address the methane transport and chloride enrichment at the Ulleung Basins chimney sites, and contributed the modeling component to a study focusing on pore-scale controls on gas hydrate distribution in sediments from the Andaman Sea. These efforts resulted in two manuscripts currently under review, and contributed the modeling component of another pare, also under review. Lessons learned from these efforts are the basis of a mini-workshop to be held at Oregon State University (Feb 2014) to instruct

  14. Cascadia Onshore-Offshore Site Response, Submarine Sediment Mobilization, and Earthquake Recurrence

    Science.gov (United States)

    Gomberg, J.

    2018-02-01

    Local geologic structure and topography may modify arriving seismic waves. This inherent variation in shaking, or "site response," may affect the distribution of slope failures and redistribution of submarine sediments. I used seafloor seismic data from the 2011 to 2015 Cascadia Initiative and permanent onshore seismic networks to derive estimates of site response, denoted Sn, in low- and high-frequency (0.02-1 and 1-10 Hz) passbands. For three shaking metrics (peak velocity and acceleration and energy density) Sn varies similarly throughout Cascadia and changes primarily in the direction of convergence, roughly east-west. In the two passbands, Sn patterns offshore are nearly opposite and range over an order of magnitude or more across Cascadia. Sn patterns broadly may be attributed to sediment resonance and attenuation. This and an abrupt step in the east-west trend of Sn suggest that changes in topography and structure at the edge of the continental margin significantly impact shaking. These patterns also correlate with gravity lows diagnostic of marginal basins and methane plumes channeled within shelf-bounding faults. Offshore Sn exceeds that onshore in both passbands, and the steepest slopes and shelf coincide with the relatively greatest and smallest Sn estimates at low and high frequencies, respectively; these results should be considered in submarine shaking-triggered slope stability failure studies. Significant north-south Sn variations are not apparent, but sparse sampling does not permit rejection of the hypothesis that the southerly decrease in intervals between shaking-triggered turbidites and great earthquakes inferred by Goldfinger et al. (2012, 2013, 2016) and Priest et al. (2017) is due to inherently stronger shaking southward.

  15. Performance testing of the sediment-contaminant transport model, SERATRA, at different rivers

    International Nuclear Information System (INIS)

    Onishi, Y.; Yabusaki, S.B.; Kincaid, C.T.

    1982-04-01

    Mathematical models of sediment-contaminant migration in surface water must account for transport, intermedia transfer, decay and degradation, and transformation processes. The unsteady, two dimensional, sediment-contaminant transport code, SERATRA (Onishi, Schreiber and Codell 1980) includes these mechanisms. To assess the accuracy of SERATRA to simulate the sediment-contaminant transport and fate processes, the code was tested against one-dimensional analytical solutions, checked for its mass balance, and applied to field sites. The field application cases ranged from relatively simple, steady conditions to unsteady, nonuniform conditions for large, intermediate, and small rivers. It was found that SERATRA is capable of simulating sediment-contaminant transport under a wide range of conditions

  16. Limitation and applicability of microtremor records for site-response estimation

    Science.gov (United States)

    Song, G.; Kang, T.; Park, S.

    2010-12-01

    Site effects are the modifications of seismic motions which are traveling through near-surface materials. The impedance contrast between the topmost layer and bedrock may significantly amplify ground motions and augment their durations. Inelastic behavior of the geological media such as highly fractured/weathered rocks and unconsolidated sediments may absorb seismic energy, and thus damp the resulting ground motions. It is inherently most desirable to evaluate the site effects using seismic records from large earthquakes. If there are only small events that will be recorded by several seismograph stations, it becomes difficult to evaluate site effects using earthquake data. Recently a number of studies pay attention to microtremor records to assess site effects. The main reason of such efforts is that measurements are relatively easy regardless of site condition and cost-effective without necessity of waiting for earthquakes or of using active sources. Especially microtremor measurements are exclusively a useful option to assess site effects, and thus seismic microzonation, in the urban area and/or region of low to moderate seismicity. Spectral ratios of horizontal components to vertical component (HVSR) of microtremor records have been popular for estimation of site resonant frequency. Although some studies have shown that the amplitude of spectral ratios is an indicator of site amplification relative to bedrock motion, there are still debates on it. This discrepancy may originate from the deficiency of our understanding on the nature of microtremor. Therefore, it is important to understand the limitation and applicability of microtremor records for site-effect assessments. The focus on this problem is how microtremor responses on the subsurface structures and their physical properties, and how parameters deduced from microtremor analyses are related to site responses during earthquake ground motions. In order to investigate how these issues have a practical

  17. Sediment-to-Water Partition Coefficients: the Influence of Physicochemical and Seasonal Factors in Eastern Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Yankovich, Tamara L. [International Atomic Energy Agency, P.O. Box 100, 1400 Vienna (Austria); Shultz, Carmen; Hartwig, Dale; Wills, C. Anne [Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, K0J 1J0 (Canada); Beresford, Nicholas A. [NERC Centre for Ecology and Hydrology, Lancaster Environment Center, Library Av., Bailrigg, Lancaster, LA1 4AP (United Kingdom); School of Environment and Life Sciences, University of Salford, Manchester, M4 4WT (United Kingdom); Wood, Michael D. [School of Environment and Life Sciences, University of Salford, Manchester, M4 4WT (United Kingdom)

    2014-07-01

    not under-estimated or to take site-specific measurements of surface waters and sediments to facilitate quantification of site-specific K{sub d} values for application on a site-by-site basis. To gain a better understanding of the factors that contribute to the variability of K{sub d}, systematic sampling of surface waters and bed sediments, and the site-specific factors that could influence K{sub d}, was carried out at 119 locations in Eastern Ontario between 2001 and 2006. Measurements of 35 parameters were taken, in addition to site-specific factors, such as sediment type, geology, proximity to radionuclide and contaminant sources, and others. The influence of such factors on variability and the application of K{sub d} values in EIA will be discussed. These data will contribute to work that is being undertaken as part of the International Atomic Energy Agency (IAEA)'s Modelling and Data for Radiological Impact Assessments (MODARIA) programme within Working Group 4, which is focused on the analysis of radioecological data in IAEA Technical Reports Series publications to identify key radionuclides and uncertainties associated with parameter values for human and wildlife assessment. (authors)

  18. Development and application of an innovative expert decision support system to manage sediments and to assess environmental risk in freshwater ecosystems.

    Science.gov (United States)

    Dagnino, Alessandro; Bo, Tiziano; Copetta, Andrea; Fenoglio, Stefano; Oliveri, Caterina; Bencivenga, Mauro; Felli, Angelo; Viarengo, Aldo

    2013-10-01

    With the aim of supporting decision makers to manage contamination in freshwater environments, an innovative expert decision support system (EDSS) was developed. The EDSS was applied in a sediment quality assessment along the Bormida river (NW, Italy) which has been heavily contaminated by an upstream industrial site for more than a century. Sampling sites were classified by means of comparing chemical concentrations with effect-based target values (threshold and probable effect concentrations). The level of each contaminant and the combined toxic pressure were used to rank sites into three categories: (i) uncontaminated (8 sites), (ii) mildly contaminated (4) and (iii) heavily contaminated (19). In heavily contaminated sediments, an environmental risk index (EnvRI) was determined by means of integrating chemical data with ecotoxicological and ecological parameters (triad approach). In addition a sediment risk index (SedRI) was computed from combining chemical and ecotoxicological data. Eight sites exhibited EnvRI values ≥0.25, the safety threshold level (range of EnvRI values: 0.14-0.31) whereas SedRI exceeded the safety threshold level at 6 sites (range of SedRI values: 0.16-0.36). At sites classified as mildly contaminated, sublethal biomarkers were integrated with chemical data into a biological vulnerability index (BVI), which exceeded the safety threshold level at one site (BVI value: 0.28). Finally, potential human risk was assessed in selected stations (11 sites) by integrating genotoxicity biomarkers (GTI index falling in the range 0.00-0.53). General conclusions drawn from the EDSS data include: (i) in sites classified as heavily contaminated, only a few exhibited some significant, yet limited, effects on biodiversity; (ii) restrictions in re-using sediments from heavily contaminated sites found little support in ecotoxicological data; (iii) in the majority of the sites classified as mildly contaminated, tested organisms exhibited low response levels

  19. Development and application of freshwater sediment-toxicity benchmarks for currently used pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Nowell, Lisa H., E-mail: lhnowell@usgs.gov [U.S. Geological Survey, California Water Science Center, Placer Hall, 6000 J Street, Sacramento, CA 95819 (United States); Norman, Julia E., E-mail: jnorman@usgs.gov [U.S. Geological Survey, Oregon Water Science Center, 2130 SW 5" t" h Avenue, Portland, OR 97201 (United States); Ingersoll, Christopher G., E-mail: cingersoll@usgs.gov [U.S. Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, MO 65021 (United States); Moran, Patrick W., E-mail: pwmoran@usgs.gov [U.S. Geological Survey, Washington Water Science Center, 934 Broadway, Suite 300, Tacoma, WA 98402 (United States)

    2016-04-15

    Sediment-toxicity benchmarks are needed to interpret the biological significance of currently used pesticides detected in whole sediments. Two types of freshwater sediment benchmarks for pesticides were developed using spiked-sediment bioassay (SSB) data from the literature. These benchmarks can be used to interpret sediment-toxicity data or to assess the potential toxicity of pesticides in whole sediment. The Likely Effect Benchmark (LEB) defines a pesticide concentration in whole sediment above which there is a high probability of adverse effects on benthic invertebrates, and the Threshold Effect Benchmark (TEB) defines a concentration below which adverse effects are unlikely. For compounds without available SSBs, benchmarks were estimated using equilibrium partitioning (EqP). When a sediment sample contains a pesticide mixture, benchmark quotients can be summed for all detected pesticides to produce an indicator of potential toxicity for that mixture. Benchmarks were developed for 48 pesticide compounds using SSB data and 81 compounds using the EqP approach. In an example application, data for pesticides measured in sediment from 197 streams across the United States were evaluated using these benchmarks, and compared to measured toxicity from whole-sediment toxicity tests conducted with the amphipod Hyalella azteca (28-d exposures) and the midge Chironomus dilutus (10-d exposures). Amphipod survival, weight, and biomass were significantly and inversely related to summed benchmark quotients, whereas midge survival, weight, and biomass showed no relationship to benchmarks. Samples with LEB exceedances were rare (n = 3), but all were toxic to amphipods (i.e., significantly different from control). Significant toxicity to amphipods was observed for 72% of samples exceeding one or more TEBs, compared to 18% of samples below all TEBs. Factors affecting toxicity below TEBs may include the presence of contaminants other than pesticides, physical/chemical characteristics

  20. Development and application of freshwater sediment-toxicity benchmarks for currently used pesticides

    International Nuclear Information System (INIS)

    Nowell, Lisa H.; Norman, Julia E.; Ingersoll, Christopher G.; Moran, Patrick W.

    2016-01-01

    Sediment-toxicity benchmarks are needed to interpret the biological significance of currently used pesticides detected in whole sediments. Two types of freshwater sediment benchmarks for pesticides were developed using spiked-sediment bioassay (SSB) data from the literature. These benchmarks can be used to interpret sediment-toxicity data or to assess the potential toxicity of pesticides in whole sediment. The Likely Effect Benchmark (LEB) defines a pesticide concentration in whole sediment above which there is a high probability of adverse effects on benthic invertebrates, and the Threshold Effect Benchmark (TEB) defines a concentration below which adverse effects are unlikely. For compounds without available SSBs, benchmarks were estimated using equilibrium partitioning (EqP). When a sediment sample contains a pesticide mixture, benchmark quotients can be summed for all detected pesticides to produce an indicator of potential toxicity for that mixture. Benchmarks were developed for 48 pesticide compounds using SSB data and 81 compounds using the EqP approach. In an example application, data for pesticides measured in sediment from 197 streams across the United States were evaluated using these benchmarks, and compared to measured toxicity from whole-sediment toxicity tests conducted with the amphipod Hyalella azteca (28-d exposures) and the midge Chironomus dilutus (10-d exposures). Amphipod survival, weight, and biomass were significantly and inversely related to summed benchmark quotients, whereas midge survival, weight, and biomass showed no relationship to benchmarks. Samples with LEB exceedances were rare (n = 3), but all were toxic to amphipods (i.e., significantly different from control). Significant toxicity to amphipods was observed for 72% of samples exceeding one or more TEBs, compared to 18% of samples below all TEBs. Factors affecting toxicity below TEBs may include the presence of contaminants other than pesticides, physical/chemical characteristics

  1. Does bioleaching represent a biotechnological strategy for remediation of contaminated sediments?

    Energy Technology Data Exchange (ETDEWEB)

    Fonti, Viviana, E-mail: v.fonti@univpm.it; Dell' Anno, Antonio; Beolchini, Francesca

    2016-09-01

    Bioleaching is a consolidated biotechnology in the mining industry and in bio-hydrometallurgy, where microorganisms mediate the solubilisation of metals and semi-metals from mineral ores and concentrates. Bioleaching also has the potential for ex-situ/on-site remediation of aquatic sediments that are contaminated with metals, which represent a key environmental issue of global concern. By eliminating or reducing (semi-)metal contamination of aquatic sediments, bioleaching may represent an environmentally friendly and low-cost strategy for management of contaminated dredged sediments. Nevertheless, the efficiency of bioleaching in this context is greatly influenced by several abiotic and biotic factors. These factors need to be carefully taken into account before selecting bioleaching as a suitable remediation strategy. Here we review the application of bioleaching for sediment bioremediation, and provide a critical view of the main factors that affect its performance. We also discuss future research needs to improve bioleaching strategies for contaminated aquatic sediments, in view of large-scale applications. - Highlights: • Bioleaching may represent a sustainable strategy for contaminated dredged sediments • The performance is greatly influenced by several abiotic and biotic factors • Geochemical characteristics and metal partitioning have a key role • Sulphide minerals in the sediment are a favorable element • Microorganisms other than Fe/S oxidisers may open new perspectives.

  2. Does bioleaching represent a biotechnological strategy for remediation of contaminated sediments?

    International Nuclear Information System (INIS)

    Fonti, Viviana; Dell'Anno, Antonio; Beolchini, Francesca

    2016-01-01

    Bioleaching is a consolidated biotechnology in the mining industry and in bio-hydrometallurgy, where microorganisms mediate the solubilisation of metals and semi-metals from mineral ores and concentrates. Bioleaching also has the potential for ex-situ/on-site remediation of aquatic sediments that are contaminated with metals, which represent a key environmental issue of global concern. By eliminating or reducing (semi-)metal contamination of aquatic sediments, bioleaching may represent an environmentally friendly and low-cost strategy for management of contaminated dredged sediments. Nevertheless, the efficiency of bioleaching in this context is greatly influenced by several abiotic and biotic factors. These factors need to be carefully taken into account before selecting bioleaching as a suitable remediation strategy. Here we review the application of bioleaching for sediment bioremediation, and provide a critical view of the main factors that affect its performance. We also discuss future research needs to improve bioleaching strategies for contaminated aquatic sediments, in view of large-scale applications. - Highlights: • Bioleaching may represent a sustainable strategy for contaminated dredged sediments • The performance is greatly influenced by several abiotic and biotic factors • Geochemical characteristics and metal partitioning have a key role • Sulphide minerals in the sediment are a favorable element • Microorganisms other than Fe/S oxidisers may open new perspectives

  3. Environmental surveillance results for 1995 for the Hazelwood Interim Storage Site

    International Nuclear Information System (INIS)

    McCague, J.C.

    1996-01-01

    This memorandum presents and interprets analytical results and measurements obtained as part of the 1995 environmental surveillance program for the Hazelwood Interim Storage Site (HISS) under the Formerly Utilized Sites Remedial Action Program (FUSRAP). The discussion provides a comparative analysis of average historical background conditions and applicable regulatory criteria to the 1995 results reported for external gamma radiation and for samples from the media investigated (air, surface water, sediment, groundwater, and stormwater). Results from the 1995 environmental surveillance program at HISS indicate that, with the exception of thorium-230 in streambed sediment, applicable US Department of Energy (DOE) guidelines were not exceeded for any measured parameter or for any dose calculated for potentially exposed members of the general public. In the absence of sediment guidelines, DOE soil guidelines serve as a standard of comparison for data obtained from stream bed sediment; two samples from downstream locations contained concentrations of thorium-230 that exceeded DOE soil guidelines. All stormwater sample results were in compliance with permit-specified limits. Other radioactive materials include radium 226 and natural uranium

  4. Biogeochemical Regeneration of a Nodule Mining Disturbance Site: Trace Metals, DOC and Amino Acids in Deep-Sea Sediments and Pore Waters

    Directory of Open Access Journals (Sweden)

    Sophie A. L. Paul

    2018-04-01

    Full Text Available Increasing interest in deep-sea mineral resources, such as polymetallic nodules, calls for environmental research about possible impacts of mineral exploitation on the deep-sea ecosystem. So far, little geochemical comparisons of deep-sea sediments before and after mining induced disturbances have been made, and thus long-term environmental effects of deep-sea mining are unknown. Here we present geochemical data from sediment cores from an experimental disturbance area at 4,100 m water depth in the Peru Basin. The site was revisited in 2015, 26 years after a disturbance experiment mimicking nodule mining was carried out and compared to sites outside the experimental zone which served as a pre-disturbance reference. We investigated if signs of the disturbance are still visible in the solid phase and the pore water after 26 years or if pre-disturbance conditions have been re-established. Additionally, a new disturbance was created during the cruise and sampled 5 weeks later to compare short- and longer-term impacts. The particulate fraction and pore water were analyzed for major and trace elements to study element distribution and processes in the surface sediment. Pore water and bottom water samples were also analyzed for oxygen, nitrate, dissolved organic carbon, and dissolved amino acids, to examine organic matter degradation processes. The study area of about 11 km2 was found to be naturally more heterogeneous than expected, requiring an analysis of spatial variability before the disturbed and undisturbed sites can be compared. The disturbed sites exhibit various disturbance features: some surface sediments were mixed through, others had the top layer removed and some had additional material deposited on top. Pore water constituents have largely regained pre-disturbance gradients after 26 years. The solid phase, however, shows clear differences between disturbed and undisturbed sites in the top 20 cm so that the impact is still visible in the

  5. Sediment Capping and Natural Recovery, Contaminant Transport Fundamentals With Applications to Sediment Caps

    National Research Council Canada - National Science Library

    Petrovski, David M; Corcoran, Maureen K; May, James H; Patrick, David M

    2005-01-01

    Engineered sediment caps and natural recovery are in situ remedial alternatives for contaminated sediments, which consist of the artificial or natural placement of a layer of material over a sediment...

  6. Effects of fine sediment, hyporheic flow, and spawning site characteristics on survival and development of bull trout embryos

    Science.gov (United States)

    Bowerman, Tracy; Neilson, Bethany; Budy, Phaedra

    2014-01-01

    Successful spawning is imperative for the persistence of salmonid populations, but relatively little research has been conducted to evaluate factors affecting early life-stage survival for bull trout (Salvelinus confluentus), a threatened char. We conducted a field experiment to assess the relationship between site-specific environmental factors and bull trout embryo survival and fry emergence timing. Survival from egg to hatch was negatively related to percent fine sediment (bull trout egg survival, but early life-stage success may ultimately be limited by intrusion of fine sediment into the incubation environment.

  7. Early Site Permit Demonstration Program: Siting Guide, Site selection and evaluation criteria for an early site permit application

    International Nuclear Information System (INIS)

    1993-01-01

    In August 1991, the Joint Contractors came to agreement with Sandia National Laboratories (SNL) and the Department of Energy (DOE) on a workscope for the cost-shared Early Site Permit Demonstration Program. One task within the scope was the development of a guide for site selection criteria and procedures. A generic Siting Guide his been prepared that is a roadmap and tool for applicants to use developing detailed siting plans for their specific region of the country. The guide presents three fundamental principles that, if used, ensure a high degree of success for an ESP applicant. First, the site selection process should take into consideration environmentally diverse site locations within a given region of interest. Second, the process should contain appropriate opportunities for input from the public. Third, the process should be applied so that it is clearly reasonable to an impartial observer, based on appropriately selected criteria, including criteria which demonstrate that the site can host an advanced light water reactor (ALWR). The Siting Guide provides for a systematic, comprehensive site selection process in which three basic types of criteria (exclusionary, avoidance, and suitability) are presented via a four-step procedure. It provides a check list of the criteria for each one of these steps. Criteria are applied qualitatively, as well as presented numerically, within the guide. The applicant should use the generic guide as an exhaustive checklist, customizing the guide to his individual situation

  8. Luminescence chronology of cave sediments at the Atapuerca paleoanthropological site, Spain.

    Science.gov (United States)

    Berger, G W; Pérez-González, A; Carbonell, E; Arsuaga, J L; Bermúdez de Castro, J-M; Ku, T-L

    2008-08-01

    Ascertaining the timing of the peopling of Europe, after the first out-of-Africa demographic expansion at the end of the Pliocene, is of great interest to paleoanthropologists. One of the earliest direct evidences for fossil hominins in western Europe comes from an infilled karstic cave site called Gran Dolina at Atapuerca, in a stratum approximately 1.5m below the Brunhes-Matuyama (B-M) geomagnetic boundary (780ka) within lithostratigraphic unit TD6. However, most of the meters of fossil- and tool-bearing strata at Gran Dolina have been difficult to date. Therefore, we applied both thermoluminescence (TL) and infrared-stimulated-luminescence (IRSL) multi-aliquot dating methods to fine-silt fractions from sediment samples within Gran Dolina and the nearby Galería cave site. We also applied these methods to samples from the present-day surface soils on the surrounding limestone hill slopes to test the luminescence-clock-zeroing-by-daylight assumption. Within the uppermost 4m of the cave deposits at Gran Dolina, TL and paired TL and IRSL ages range stratigraphically from 198+/-19ka to 244+/-26ka. Throughout Gran Dolina, all luminescence results are stratigraphically self-consistent and, excepting results from two stratigraphic units, are consistent with prior ESR-U-series ages from progressively deeper strata. Thermoluminescence ages culminate at 960+/-120ka approximately 1m below the 780ka B-M boundary. At Galería, with one exception, TL and IRSL ages range stratigraphically downward from 185+/-26ka to 503+/-95ka at the base of the lowermost surface-inwash facies. These results indicate that TL and (sometimes) IRSL are useful dating tools for karstic inwash sediments older than ca. 100ka, and that a more accurate chronostratigraphic correlation is now possible among the main Atapuerca sites (Gran Dolina, Galería, Sima de los Huesos). Furthermore, the oldest TL age of ca. 960ka from Gran Dolina, consistent with biostratigraphic and paleomagnetic evidence, implies

  9. Applications of dendrochronology and sediment geochronology to establish reference episodes for evaluations of environmental radioactivity

    International Nuclear Information System (INIS)

    Waugh, W.J.; Carroll, J.; Abraham, J.D.; Landeen, D.S.

    1998-01-01

    Dendrochronology and sediment geochronology have been used to demonstrate retrospective monitoring of environmental radioactivity at United States Department of Energy (DOE) sites. 14 C in annual growth rings of sagebrush preserved the temporal and spatial patterns of 14 C resulting from dispersion downwind of a nuclear fuel processing facility at the Hanford Site in Washington State. As far as 10 km downwind of the facility, 14 C concentrations were significantly higher in growth rings formed during a fuel processing episode than in rings produced during preoperational or postoperational episodes. An episode of uranium mill tailings deposition in pond sediments at the Grand Junction Office in Colorado was reconstructed using 210 Pb geochronology constrained by a marker of peak 137 Cs fallout. Uranium concentrations in ponds sediments deposited after the processing episode provide a reasonable cleanup standard. These reference episodes of environmental radioactivity reconstructed from measurements taken within contaminated environments can improve or replace reference area data as baseline information for dose reconstructions, risk assessments, and the establishment of cleanup standards. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Development and application of freshwater sediment-toxicity benchmarks for currently used pesticides

    Science.gov (United States)

    Nowell, Lisa H.; Norman, Julia E.; Ingersoll, Christopher G.; Moran, Patrick W.

    2016-01-01

    Sediment-toxicity benchmarks are needed to interpret the biological significance of currently used pesticides detected in whole sediments. Two types of freshwater sediment benchmarks for pesticides were developed using spiked-sediment bioassay (SSB) data from the literature. These benchmarks can be used to interpret sediment-toxicity data or to assess the potential toxicity of pesticides in whole sediment. The Likely Effect Benchmark (LEB) defines a pesticide concentration in whole sediment above which there is a high probability of adverse effects on benthic invertebrates, and the Threshold Effect Benchmark (TEB) defines a concentration below which adverse effects are unlikely. For compounds without available SSBs, benchmarks were estimated using equilibrium partitioning (EqP). When a sediment sample contains a pesticide mixture, benchmark quotients can be summed for all detected pesticides to produce an indicator of potential toxicity for that mixture. Benchmarks were developed for 48 pesticide compounds using SSB data and 81 compounds using the EqP approach. In an example application, data for pesticides measured in sediment from 197 streams across the United States were evaluated using these benchmarks, and compared to measured toxicity from whole-sediment toxicity tests conducted with the amphipod Hyalella azteca (28-d exposures) and the midge Chironomus dilutus (10-d exposures). Amphipod survival, weight, and biomass were significantly and inversely related to summed benchmark quotients, whereas midge survival, weight, and biomass showed no relationship to benchmarks. Samples with LEB exceedances were rare (n = 3), but all were toxic to amphipods (i.e., significantly different from control). Significant toxicity to amphipods was observed for 72% of samples exceeding one or more TEBs, compared to 18% of samples below all TEBs. Factors affecting toxicity below TEBs may include the presence of contaminants other than pesticides, physical

  11. Modelling Zn(II) sorption onto clayey sediments using a multi-site ion-exchange model

    International Nuclear Information System (INIS)

    Tertre, E.; Beaucaire, C.; Coreau, N.; Juery, A.

    2009-01-01

    In environmental studies, it is necessary to be able to predict the behaviour of contaminants in more or less complex physico-chemical contexts. The improvement of this prediction partly depends on establishing thermodynamic models that can describe the behaviour of these contaminants and, in particular, the sorption reactions on mineral surfaces. In this way, based on the mass action law, it is possible to use surface complexation models and ion exchange models. Therefore, the aim of this study is (i) to develop an ion-exchange model able to describe the sorption of transition metal onto pure clay minerals and (ii) to test the ability of this approach to predict the sorption of these elements onto natural materials containing clay minerals (i.e. soils/sediments) under various chemical conditions. This study is focused on the behaviour of Zn(II) in the presence of clayey sediments. Considering that clay minerals are cation exchangers containing multiple sorption sites, it is possible to interpret the sorption of Zn(II), as well as competitor cations, by ion-exchange equilibria with the clay minerals. This approach is applied with success to interpret the experimental data obtained previously in the Zn(II)-H + -Na + -montmorillonite system. The authors' research team has already studied the behaviour of Na + , K + , Ca 2+ and Mg 2+ versus pH in terms of ion exchange onto pure montmorillonite, leading to the development of a thermodynamic database including the exchange site concentrations associated with montmorillonite and the selectivity coefficients of Na + , K + , Ca 2+ , Mg 2+ , and Zn 2+ versus H + . In the present study, experimental isotherms of Zn(II) on two different sediments in batch reactors at different pH and ionic strengths, using NaCl and CaSO 4 as electrolytes are reported. Assuming clay minerals are the main ion-exchanging phases, it is possible to predict Zn(II) sorption onto sediments under different experimental conditions, using the previously

  12. Application of 137Cs and 210Pb radionuclides to determine sedimentation rates of recent sediments from Admiralty Bay, Antarctica Peninsula

    International Nuclear Information System (INIS)

    Nascimento, Mylene Giseli do; Martins, Cesar de Castro; Figueira, Rubens C.L.; Montone, Rosalinda C.; Mahiques, Michel M. de; Tessler, Moyses G.

    2009-01-01

    Studies about natural and artificial radionuclides in areas such as the Antarctic are key to understand natural and dynamic processes in marine environments. These studies are important to determine levels of radioactive elements and local sedimentation rates. Five marine sediment cores were collected in different points of Admiralty Bay, in the Antarctic Peninsula. The purpose of this study was to determine 137 Cs, 226 Ra and 210 Pb and sedimentation rates at each site. 137 Cs, 210 Pb and 226 Ra were assayed by gamma-counting through direct measurement of the peak at 661 keV, 47 keV and 609 keV, respectively. Sedimentation rates were obtained by 137 Cs and 210 Pb (CIC and CRS). The activities for 137 Cs ranged from 0.84 to 7.09 Bq kg -1 ; to 226 Ra from 6.77 to 31.07 Bq kg -1 for 210 Pb ranged from 1.10 to 36.90 Bq kg -1 . The sedimentation rates obtained by the three models ranged from 0.11±0.01 cm y -1 to 0.46±0.05 cm y -1 . The levels of 137 Cs registered in this study, as well as in other studies in the Antarctic region indicate that global fallout is the main cause of artificial radionuclides present in this environment, since the Antarctic has not suffered a direct action of human activities that released radioactive elements. The possible grain size variations that occur in the studied points of Admiralty Bay may explain the differences found in the vertical distribution of radionuclides, because of the different values of sedimentation rates and respective dating determined in their profiles. (author)

  13. Water Quality and Sedimentation Data of the Coastal Intensive Site Network (CISNet) Long Term Monitoring Sites in Kaneohe Bay, Oahu, Hawaii from 1998 to 2001 (NODC Accession 0001473)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A long term project to monitor water quality and sediment processes in Kaneohe Bay was initiated in November 1998 and continued through July 2001. Four primary sites...

  14. Quantifying postfire aeolian sediment transport using rare earth element tracers

    Science.gov (United States)

    Dukes, David; Gonzales, Howell B.; Ravi, Sujith; Grandstaff, David E.; Van Pelt, R. Scott; Li, Junran; Wang, Guan; Sankey, Joel B.

    2018-01-01

    Grasslands, which provide fundamental ecosystem services in many arid and semiarid regions of the world, are undergoing rapid increases in fire activity and are highly susceptible to postfire-accelerated soil erosion by wind. A quantitative assessment of physical processes that integrates fire-wind erosion feedbacks is therefore needed relative to vegetation change, soil biogeochemical cycling, air quality, and landscape evolution. We investigated the applicability of a novel tracer technique—the use of multiple rare earth elements (REE)—to quantify soil transport by wind and to identify sources and sinks of wind-blown sediments in both burned and unburned shrub-grass transition zone in the Chihuahuan Desert, NM, USA. Results indicate that the horizontal mass flux of wind-borne sediment increased approximately threefold following the fire. The REE tracer analysis of wind-borne sediments shows that the source of the horizontal mass flux in the unburned site was derived from bare microsites (88.5%), while in the burned site it was primarily sourced from shrub (42.3%) and bare (39.1%) microsites. Vegetated microsites which were predominantly sinks of aeolian sediments in the unburned areas became sediment sources following the fire. The burned areas showed a spatial homogenization of sediment tracers, highlighting a potential negative feedback on landscape heterogeneity induced by shrub encroachment into grasslands. Though fires are known to increase aeolian sediment transport, accompanying changes in the sources and sinks of wind-borne sediments may influence biogeochemical cycling and land degradation dynamics. Furthermore, our experiment demonstrated that REEs can be used as reliable tracers for field-scale aeolian studies.

  15. Nematode communities in contaminated river sediments

    International Nuclear Information System (INIS)

    Heininger, Peter; Hoess, Sebastian; Claus, Evelyn; Pelzer, Juergen; Traunspurger, Walter

    2007-01-01

    Nematode communities of eight sites from three river catchments were investigated in terms of the genera composition, feeding types, and life-history strategists. The sampling sites showed a gradient of anthropogenic contamination with heavy metals and organic pollutants being important factors in differentiating the sites. Nematode community structure was related to sediment pollution and the hydro-morphological structure of the sampling sites. Heavily contaminated sites were characterized by communities with high relative abundances of omnivorous and predacious nematodes (Tobrilus, c-p 3; Mononchus, c-p 4), while sites with low to medium contamination were dominated by bacterivorous nematodes (Monhystera, Daptonema; c-p 2) or suction feeders (Dorylaimus, c-p 4). The relatively high Maturity Index values in the heavily polluted sites were surprising. Nematodes turned out to be a suitable organism group for monitoring sediment quality, with generic composition being the most accurate indicator for assessing differences in nematode community structure. - Nematode community structure of river sediments is related to pollution and site structure

  16. Nematode communities in contaminated river sediments

    Energy Technology Data Exchange (ETDEWEB)

    Heininger, Peter [Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, 56068 Koblenz (Germany); Hoess, Sebastian [Ecossa - Ecological Sediment and Soil Assessment, Thierschstr. 43, 80538 Munich (Germany); Claus, Evelyn [Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, 56068 Koblenz (Germany); Pelzer, Juergen [Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, 56068 Koblenz (Germany); Traunspurger, Walter [University of Bielefeld, Department of Animal Ecology, Morgenbreede 45, 33615 Bielefeld (Germany)]. E-mail: traunspurger@uni-bielefeld.de

    2007-03-15

    Nematode communities of eight sites from three river catchments were investigated in terms of the genera composition, feeding types, and life-history strategists. The sampling sites showed a gradient of anthropogenic contamination with heavy metals and organic pollutants being important factors in differentiating the sites. Nematode community structure was related to sediment pollution and the hydro-morphological structure of the sampling sites. Heavily contaminated sites were characterized by communities with high relative abundances of omnivorous and predacious nematodes (Tobrilus, c-p 3; Mononchus, c-p 4), while sites with low to medium contamination were dominated by bacterivorous nematodes (Monhystera, Daptonema; c-p 2) or suction feeders (Dorylaimus, c-p 4). The relatively high Maturity Index values in the heavily polluted sites were surprising. Nematodes turned out to be a suitable organism group for monitoring sediment quality, with generic composition being the most accurate indicator for assessing differences in nematode community structure. - Nematode community structure of river sediments is related to pollution and site structure.

  17. Offshore Wind Guidance Document: Oceanography and Sediment Stability (Version 1) Development of a Conceptual Site Model.

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Jesse D.; Jason Magalen; Craig Jones

    2014-06-01

    This guidance document provide s the reader with an overview of the key environmental considerations for a typical offshore wind coastal location and the tools to help guide the reader through a thoro ugh planning process. It will enable readers to identify the key coastal processes relevant to their offshore wind site and perform pertinent analysis to guide siting and layout design, with the goal of minimizing costs associated with planning, permitting , and long - ter m maintenance. The document highlight s site characterization and assessment techniques for evaluating spatial patterns of sediment dynamics in the vicinity of a wind farm under typical, extreme, and storm conditions. Finally, the document des cribe s the assimilation of all of this information into the conceptual site model (CSM) to aid the decision - making processes.

  18. Effects of land disposal of municipal sewage sludge on soil, streambed sediment, and ground- and surface-water quality at a site near Denver, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Gaggiani, N.G.

    1991-01-01

    The report describes the effects of burial and land application of municipal sewage sludge on soil and streambed sediment and water quality in the underlying aquifers and surface water within and around the Lowry sewage-sludge-disposal area. The existing ground-water observation-well network at the disposal area was expanded for the study. Surface-water-sampling sites were selected so that runoff could be sampled from intense rainstorms or snowmelt. The sampling frequency for ground-water and surface-water runoff was changed from yearly to quarterly, and soil samples were collected. Four years of data were collected from 1984 to 1987 during the expanded monitoring program at the Lowry sewage-sludge-disposal area. These data, in addition to the data collected by the U.S. Geological Survey from 1981 to 1983, were used to determine effects of sewage-sludge-disposal on soil and streambed sediment and surface- and ground-water quality at the disposal area.

  19. Arsenic Fate, Transport And Stability Study: Groundwater, Surface Water, Soil And Sediment Investigation At Fort Devens Superfund Site

    Science.gov (United States)

    A field investigation was conducted to examine the distribution of arsenic in groundwater, surface water, and sediments at the Fort Devens Superfund Site. The study area encompassed a portion of plow Shop Pond (Red Cove), which receives groundwater discharge from the aquifer und...

  20. Ability of salt marsh plants for TBT remediation in sediments.

    Science.gov (United States)

    Carvalho, Pedro N; Basto, M Clara P; Silva, Manuela F G M; Machado, Ana; Bordalo, A A; Vasconcelos, M Teresa S D

    2010-07-01

    The capability of Halimione portulacoides, Spartina maritima, and Sarcocornia fruticosa (halophytes very commonly found in salt marshes from Mediterranean areas) for enhancing remediation of tributyltin (TBT) from estuarine sediments was investigated, using different experimental conditions. The influence of H. portulacoides on degradation of the butyltin compounds was assessed in two different ways: (1) a 9-month ex situ study carried out in a site of Sado River estuary, center of Portugal, which used polluted sediments collected at other nonvegetated site from the same estuary; and (2) a 12-month laboratorial study, using both plant and sediment collected at a relatively clean site of Cávado River estuary, north of Portugal, the sediment being doped with TBT, DBT, and MBT at the beginning of the experiment. The role of both S. fruticosa and S. maritima on TBT remediation in sediments was evaluated in situ, in salt marshes from Marim channel of Ria Formosa lagoon, south of Portugal, which has large areas colonized by each one of these two plants. For estimation of microbial abundance, total cell counts of sediment samples were enumerated by the DAPI direct count method. Butyltin analyses in sediment were performed using a method previously validated, which consisted of headspace solid-phase micro-extraction combined with gas chromatography-mass spectrometry after in situ ethylation (with tetraethylborate). Sediments colonized both ex situ and at lab by H. portulacoides displayed TBT levels about 30% lower than those for nonvegetated sediments with identical initial composition, after 9-12 months of plant exposure. In addition, H. portulacoides showed to be able of stimulating bacterial growth in the plant rhizosphere, which probably included degraders of TBT. In the in situ study, which compared the levels of TBT, DBT, and MBT in nonvegetated sediment and in sediments colonized by either S. maritima or S. fruticosa from the same area, TBT and DBT were only

  1. Developing Sediment Remediation Goals at Superfund Sites Based on Pore Water for the Protection of Benthic Organisms from Direct Toxicity to Non-ionic Organic Contaminants

    Science.gov (United States)

    A methodology for developing remediation goals for sites with contaminated sediments is provided. The remediation goals are based upon the concentrations of chemicals in the sediment interstitial water measured using the passive sampling technique. The passive sampling technique ...

  2. Biota-Sediment Accumulation Factor Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Biota-Sediment Accumulation Factor contains approximately 20,000 biota-sediment accumulation factors (BSAFs) from 20 locations (mostly Superfund sites) for...

  3. In-situ geophysical measurements in marine sediments: Applications in seafloor acoustics and paleoceanography

    Science.gov (United States)

    Gorgas, Thomas Joerg

    Acoustic in-situ sound speeds and attenuation were measured on the Eel River shelf, CA, with the Acoustic Lance between 5 and 15 kHz to 2.0 meters below seafloor (mbsf). A comparison with laboratory ultrasonic geoacoustic data obtained at 400 kHz on cored sediments showed faster in-situ and ultrasonic sound speeds in coarse-grained deposits in water depths to 60 m than in fine-grained deposits below that contour line. Ultrasonic attenuation was often greater than in-situ values and remained almost constant below 0.4 mbsf in these heterogeneous deposits. In-situ attenuation decreased with depth. These observations partly agree with results from other field studies, and with theoretical models that incorporate intergranular friction and dispersion from viscosity as main controls on acoustic wave propagation in marine sediments. Deviations among in-situ and laboratory acoustic data from the Eel Margin with theoretical studies were linked to scattering effects. Acoustic Lance was also deployed in homogeneous, fine-grained sediments on the inner shelf of SE Korea, where free gas was identified in late-September, but not in mid-September 1999. Free gas was evidenced by an abrupt decrease of in-situ sound speed and by characteristic changes in acoustic waveforms. These results suggest the presence of a gassy sediment layer as shallow as 2 mbsf along the 70 m bathymetry line, and was attributed to a variable abundance of free gas on short-term and/or small-regional scales on the SE Korea shelf. Bulk density variations in marine sediments obtained along the Walvis Ridge/Basin, SW Africa, at Ocean Drilling Program (ODP) Sites 1081 to 1084 were spectral-analyzed to compute high-resolution sedimentation rates (SRs) in both the time- and age domains by correctly identifying Milankovitch cycles (MCs). SRs for the ODP sites yielded age-depth models that often correlate positively with biostratigraphic data and with organic mass accumulation rates (MAR Corg), a proxy for

  4. Bronx River bed sediments phosphorus pool and phosphorus compound identification

    Science.gov (United States)

    Wang, J.; Pant, H. K.

    2008-12-01

    Phosphorus (P) transport in the Bronx River degraded water quality, decreased oxygen levels, and resulted in bioaccumulation in sediment potentially resulting in eutrophication, algal blooms and oxygen depletion under certain temperature and pH conditions. The anthropogenic P sources are storm water runoff, raw sewage discharge, fertilizer application in lawn, golf course and New York Botanical Garden; manure from the Bronx zoo; combined sewoverflows (CSO's) from parkway and Hunts Point sewage plant; pollutants from East River. This research was conducted in the urban river system in New York City area, in order to control P source, figure out P transport temporal and spatial variations and the impact on water quality; aimed to regulate P application, sharing data with Bronx River Alliance, EPA, DEP and DEC. The sediment characteristics influence the distribution and bioavailbility of P in the Bronx River. The P sequential extraction gave the quantitative analysis of the P pool, quantifying the inorganic and organic P from the sediments. There were different P pool patterns at the 15 sites, and the substantial amount of inorganic P pool indicated that a large amount P is bioavailable. The 31P- NMR (Nuclear Magnetic Resonance Spectroscopy) technology had been used to identify P species in the 15 sites of the Bronx River, which gave a qualitative analysis on phosphorus transport in the river. The P compounds in the Bronx River bed sediments are mostly glycerophophate (GlyP), nucleoside monophosphates (NMP), polynucleotides (PolyN), and few sites showed the small amount of glucose-6-phosphate (G6P), glycerophosphoethanoamine (GPEA), phosphoenopyruvates (PEP), and inosine monophosphate (IMP). The land use spatial and temporal variations influence local water P levels, P distributions, and P compositions.

  5. Insights into the Early to Late Oligocene Izu-Bonin Mariana Arc Magmatic History from Volcanic Minerals and Glass within Volcaniclastic Sediments of IODP Site U1438 and DSDP Site 296

    Science.gov (United States)

    Samajpati, E.; Hickey-Vargas, R.

    2017-12-01

    The Kyushu-Palau Ridge (KPR) is a remnant of the early Izu-Bonin-Mariana (IBM) island arc, separated by arc rifting and seafloor spreading. We examine and compare volcanic materials from two sites where the transition from IBM arc building to rifting is well sampled: DSDP Site 296 on the northern KPR crest, and recent IODP Site U1438 in the adjacent Amami-Sankaku basin to the west. The purpose of the study is to understand the origin and depositional regime of volcaniclastic sediments during the arc rifting stage. Site 1438 sedimentary Unit II and the upper part of Unit III (300 and 453 mbsf) correlate in time with sedimentary Units 1G and 2 of DSDP Site 296 (160 and 300 mbsf). The upper part of Site U1438 Unit III and Site 296 Unit 2 consist of early to late Oligocene coarse volcaniclastic sedimentary rocks. These are overlain by late Oligocene nannofossil chalks with volcanic sand and ash-rich layers at Site 296 Unit 1G, and tuffaceous silt, sand, siltstone and sandstone at Site 1438 Unit II. The chemical composition of volcanic glass shards, pyroxenes with melt inclusions and amphiboles separated from volcaniclastic sediments were analyzed by EPMA and LA-ICPMS. Glasses are found at Site 296 only, range from medium-K basalt to rhyolite and have trace element patterns typical of arc volcanics. Clinopyroxene and orthopyroxene are found as detrital grains in sediments from both sites. Mg-numbers range from 58 to 94. Interestingly, the alumina content of pyroxene grain populations from both sites increase and then decrease with decreasing Mg-number. This probably reflects control of Al contents in magma and pyroxene by suppressed plagioclase saturation, which apparently was a consistent feature of KPR volcanoes. Melt-inclusions within the pyroxenes are typically small (30-50 microns) and have similar chemical compositions within one grain. The melt inclusions range from basalt to rhyolite with moderate alkali content. Amphibole is more prevalent in late Oligocene

  6. Experimental site and design

    Energy Technology Data Exchange (ETDEWEB)

    Guenette, C. C. [SINTEF Applied Cemistry, Trondheim (Norway)

    1999-08-01

    Design and site selection criteria for the Svalbard oil spill experiments are described. All three experimental sites have coarse and mixed sediment beaches of sand and pebble; within each site wave exposure is very similar; along-shore and across-shore sediment characteristics are also relatively homogeneous. Tidal range is in the order of 0.6 m at neaps, and 1.8 m at springs. All three sites are open to wave action and are ice-free during the experimental period of mid-July to mid-October. Study plots at each site were selected for different treatments from within the continuous stretch of oiled shoreline, with oiled buffer zones between plots and at either end of the oiled zone. Treatments included mixing (tilling), sediment relocation (surf washing) and bioremediation (nutrient enrichment). Measurements and observations were carried out during the summers of 1997 and 1998. The characteristics measured were: wave and wind conditions; beach topography and elevation; sediment grain size distribution; mineral fines size distribution and mineral composition; background hydrocarbons; concentration of oil within experimental plots and the rate of oil loss over time; depth of oil penetration and thickness of the oiled sediment layer; oil concentration and toxicity of near-shore benthic sediments; mineral composition of suspended particulate material captured in sub-tidal sediment traps; and oil-fines interaction in near-shore water samples. 1 fig.

  7. Experimental site and design

    Energy Technology Data Exchange (ETDEWEB)

    Guenette, C. C. [SINTEF Applied Cemistry, Trondheim (Norway)

    1999-07-01

    Design and site selection criteria for the Svalbard oil spill experiments are described. All three experimental sites have coarse and mixed sediment beaches of sand and pebble; within each site waveexposure is very similar; along-shore and across-shore sediment characteristics are also relatively homogeneous. Tidal range is in the order of 0.6 m at neaps, and 1.8 m at springs. All three sites are open to wave action and are ice-free during the experimental period of mid-July to mid-October. Study plots at each site were selected for different treatments from within the continuous stretch of oiled shoreline, with oiled buffer zones between plots and at either end of the oiled zone. Treatments included mixing (tilling), sediment relocation (surf washing) and bioremediation (nutrient enrichment). Measurements and observations were carried out during the summers of 1997 and 1998. The characteristics measured were: wave and wind conditions; beach topography and elevation; sediment grain size distribution; mineral fines size distribution and mineral composition; background hydrocarbons; concentration of oil within experimental plots and the rate of oil loss over time; depth of oil penetration and thickness of the oiled sediment layer; oil concentration and toxicity of near-shore benthic sediments; mineral composition of suspended particulate material captured in sub-tidal sediment traps; and oil-fines interaction in near-shore water samples. 1 fig.

  8. Rates of sediment reworking at the HEBBLE site based on measurements of Th-234, Cs-137 and Pb-210

    International Nuclear Information System (INIS)

    DeMaster, D.J.; McKee, B.A.; Nittrouer, C.A.; Brewster, D.C.; Biscaye, P.E.

    1985-01-01

    Th-234, Cs-137 and Pb-210 measurements have been made on ten cores from the HEBBLE site on the Nova Scotian continental rise. Th-234 mixing coefficients from HEBBLE sediments show substantial lateral variability with values ranging from 1 to 33 cm 2 yr -1 . These mixing coefficients are one to two orders of magnitude greater than values from typical continental-rise and abyssal sediments because of high densities of benthic macrofauna. Th-234 data from HEBBLE cores indicate that particles at the sediment-water interface are mixed to depths of 1-5 cm on a 100-day time scale. Cs-137 and Pb-210 data indicate that on time scales of 30-100 yrs surface sediments are reworked to depths ranging from 1 to 12 cm. Based on Th-234 profiles from two HEBBLE cores collected less than 200 m apart during consecutive years, no temporal variability in mixing rate could be resolved. (Auth.)

  9. Cyclic Sediment Trading Between Channel and River Bed Sediments

    Science.gov (United States)

    Haddadchi, A.

    2015-12-01

    Much of the previous work on sediment tracing has focused on determining either the initial sources of the sediment (soils derive from a particular rock type) or the erosion processes generating the sediment. However, alluvial stores can be both a source and sink for sediment transported by streams. Here geochemical and fallout radionuclide tracing of river-bed and alluvial sediments are used to determine the role of secondary sources, sediment stores, as potential sources of sediment leaving Emu Creek catchment, southeastern Queensland, Australia. Activity concentrations of 137Cs on the river sediments are consistent with channel erosion being the dominant source at all sites sampled along the river. To characterise the deposition and remobilisation cycles in the catchment, a novel geochemical tracing approach was used. Successive pockets of alluvium were treated as discrete sink terms within geochemical mixing models and their source contributions compared with those of river bed sediments collected adjacent to each alluvial pocket. Three different size fractions were examined; silts and clays (banks indicates a high degree of 'trading' between the fluvial space and the alluvial space. Hence, management works aimed at primarily reducing the supply of sediments to the outlet of Emu Creek should focus on rehabilitation of channel banks in the lower catchment.

  10. Sediment acoustic index method for computing continuous suspended-sediment concentrations

    Science.gov (United States)

    Landers, Mark N.; Straub, Timothy D.; Wood, Molly S.; Domanski, Marian M.

    2016-07-11

    Suspended-sediment characteristics can be computed using acoustic indices derived from acoustic Doppler velocity meter (ADVM) backscatter data. The sediment acoustic index method applied in these types of studies can be used to more accurately and cost-effectively provide time-series estimates of suspended-sediment concentration and load, which is essential for informed solutions to many sediment-related environmental, engineering, and agricultural concerns. Advantages of this approach over other sediment surrogate methods include: (1) better representation of cross-sectional conditions from large measurement volumes, compared to other surrogate instruments that measure data at a single point; (2) high temporal resolution of collected data; (3) data integrity when biofouling is present; and (4) less rating curve hysteresis compared to streamflow as a surrogate. An additional advantage of this technique is the potential expansion of monitoring suspended-sediment concentrations at sites with existing ADVMs used in streamflow velocity monitoring. This report provides much-needed standard techniques for sediment acoustic index methods to help ensure accurate and comparable documented results.

  11. Applications of dendrochronology and sediment geochronology to establish reference episodes for evaluations of environmental radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, W.J.; Carroll, J.; Abraham, J.D.; Landeen, D.S. [Roy F. Weston, Inc., U.S. Department of Energy, Grand Junction Office, 2597 B 3/4 Road, Grand Junction, CO 81503 (United States)

    1998-12-01

    Dendrochronology and sediment geochronology have been used to demonstrate retrospective monitoring of environmental radioactivity at United States Department of Energy (DOE) sites. {sup 14}C in annual growth rings of sagebrush preserved the temporal and spatial patterns of {sup 14}C resulting from dispersion downwind of a nuclear fuel processing facility at the Hanford Site in Washington State. As far as 10 km downwind of the facility, {sup 14}C concentrations were significantly higher in growth rings formed during a fuel processing episode than in rings produced during preoperational or postoperational episodes. An episode of uranium mill tailings deposition in pond sediments at the Grand Junction Office in Colorado was reconstructed using {sup 210}Pb geochronology constrained by a marker of peak {sup 137}Cs fallout. Uranium concentrations in ponds sediments deposited after the processing episode provide a reasonable cleanup standard. These reference episodes of environmental radioactivity reconstructed from measurements taken within contaminated environments can improve or replace reference area data as baseline information for dose reconstructions, risk assessments, and the establishment of cleanup standards. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  12. WAG 2 remedial investigation and site investigation site-specific work plan/health and safety checklist for the sediment transport modeling task

    International Nuclear Information System (INIS)

    Holt, V.L.; Baron, L.A.

    1994-05-01

    This site-specific Work Plan/Health and Safety Checklist (WP/HSC) is a supplement to the general health and safety plan (HASP) for Waste Area Grouping (WAG) 2 remedial investigation and site investigation (WAG 2 RI ampersand SI) activities [Health and Safety Plan for the Remedial Investigation and Site Investigation of Waste Area Grouping 2 at the Oak Ridge National Laboratory, Oak Ridge, Tennessee (ORNL/ER-169)] and provides specific details and requirements for the WAG 2 RI ampersand SI Sediment Transport Modeling Task. This WP/HSC identifies specific site operations, site hazards, and any recommendations by Oak Ridge National Laboratory (ORNL) health and safety organizations [i.e., Industrial Hygiene (IH), Health Physics (HP), and/or Industrial Safety] that would contribute to the safe completion of the WAG 2 RI ampersand SI. Together, the general HASP for the WAG 2 RI ampersand SI (ORNL/ER-169) and the completed site-specific WP/HSC meet the health and safety planning requirements specified by 29 CFR 1910.120 and the ORNL Hazardous Waste Operations and Emergency Response (HAZWOPER) Program Manual. In addition to the health and safety information provided in the general HASP for the WAG 2 RI ampersand SI, details concerning the site-specific task are elaborated in this site-specific WP/HSC, and both documents, as well as all pertinent procedures referenced therein, will be reviewed by all field personnel prior to beginning operations

  13. Runoff, sediment transport, and landform modifications near Sheffield, Illinois

    International Nuclear Information System (INIS)

    Gray, J.R.; deVries, M.P.

    1984-01-01

    Relations among precipitation, runoff, sediment transport, and landform modifications are being evaluated at an 8.1-hectare, low-level radioactive waste disposal site near Sheffield, IL. Rainfall, runoff, and sediment discharge are measured in three basins comprising two-thirds of the site area and in a 1.10-hectare basin in undisturbed terrain 0.5 kilometer south of the site. The effects of slope, land use, and the physical characteristics of surficial material on runoff and sediment transport are evaluated at four 0.001-hectare plots - two on site and two on the undisturbed watershed. Preliminary results indicate that 890 millimeters of precipitation from July 1, 1982, through June 30, 1983, produced 230 millimeters of runoff from the site, compared to 50 millimeters of runoff from the undisturbed basin. Storm-sediment yields from the site consistently exceed yields from the undisturbed area. Runoff and sediment yields from burial-trench covers are consistently lower than yields from the site. Over 110 collapse holes were documented at the site from December 1978 through December 1982. More than 70% of these collapses formed along the periphery of trenches

  14. Runoff, sediment transport, and landform modifications near Sheffield, Illinois

    International Nuclear Information System (INIS)

    Gray, J.R.

    1984-01-01

    Relations among runoff, sediment transport, landform modifications, and precipitation are being evaluated at a 20-acre, low-level radioactive-waste disposal site near Sheffield, Ill. Rainfall, runoff, and sediment discharge are measured in three basins comprising two-thirds of the site area and in a 3.5-acre basin in undisturbed terrain 0.3 mile south of the site. The effects of slope, land use, and the physical characteristics of surficial material on runoff and sediment transport are evaluated at four 110-square-foot plots - two on site and two on the undisturbed basin. Preliminary results indicate the mean annual precipitation of 35 in. from July 1, 1982, through June 30, 1984, produced a mean of 8 in. of runoff annually from the site, compared to less than 2 in. of runoff annually from the undisturbed basin. Storm-sediment yields from the site consistently exceed yields from the undisturbed basin. Runoff and sediment yields from burial-trench covers are consistently lower than yields from the site. Two hundred and forty-four collapse holes were documented at the site from November 7, 1978, through June 7, 1984. More than 70% of these collapses formed along the periphery of trenches

  15. Prediction of bedload sediment transport for heterogeneous sediments in shape

    Science.gov (United States)

    Durafour, Marine; Jarno, Armelle; Le Bot, Sophie; Lafite, Robert; Marin, François

    2015-04-01

    Key words: Particle shape, in-situ measurements, bedload transport, heterogeneous sediments Bedload sediment transport in the coastal area is a dynamic process mainly influenced by the type of hydrodynamic forcings involved (current and/or waves), the flow properties (velocity, viscosity, depth) and sediment heterogeneity (particle size, density, shape). Although particle shape is recognized to be a significant factor in the hydrodynamic behavior of grains, this parameter is not currently implemented in bedload transport formulations: firstly because the mechanisms of initiation of motion according to particle shape are still not fully understood, and secondly due to the difficulties in defining common shape parameters. In March 2011, a large panel of in-situ instruments was deployed on two sites in the Eastern English Channel, during the sea campaign MESFLUX11. Samples of the sediment cover available for transport are collected, during a slack period, per 2cm thick strata by divers and by using a Shipeck grab. Bedload discharges along a tidal cycle are also collected with a Delft Nile Sampler (DNS; Gaweesh and Van Rijn, 1992, 1994) on both sites. The first one is characterized by a sandy bed with a low size dispersion, while the other study area implies graded sediments from fine sands to granules. A detailed analysis of the data is performed to follow the evolution of in-situ bedload fluxes on the seabed for a single current. In-situ measurements are compared to existing formulations according to a single fraction approach, using the median diameter of the mixture, and a fractionwise approach, involving a discretization of the grading curve. Results emphasize the interest to oscillate between these two methods according to the dispersion in size of the site considered. The need to apply a hiding/exposure coefficient (Egiazaroff, 1965) and a hindrance factor (Kleinhans and Van Rijn, 2002) for size heterogeneous sediments is also clearly highlighted. A really good

  16. Paleoenvironmental change as derived from loess sediment properties: Examples of last glacial loess sites from the Carpathian Basin

    Science.gov (United States)

    Lehmkuhl, Frank; Zeeden, Christian; Bösken, Janina; Eckmeier, Eileen; Hambach, Ulrich; Hauck, Thomas; Klasen, Nicole; Markovic, Slobodan; Obreht, Igor; Schulte, Philipp; Sümegi, Pal; Chu, Wei; Timar-Gabor, Alida; Veres, Daniel

    2015-04-01

    The project B1 within the CRC 806 "Our way to Europe" focuses on the "Eastern Trajectory" of modern human migration from Africa into Europe. The Middle East, and SE Europe constitute the principal areas to be investigated. SE Europe has become a special research focus since two early Homo sapiens individuals have been found at Oase Cave in the southern Banat. The fossils lack any stratigraphic context; cultural and environmental circumstances of these findings have remained unclear. In the neighbourhood of Oase Cave, however, several early Upper Palaeolithic sites, embedded in loess sequences were known since the 1950's. Some sites were re-investigated by our research team. Conceptionally we are following the idea of upland-lowland interaction, which combines parameters as sedimentary transport, sediment distribution, and paleosol development in different altitudes, all influenced by paleoclimate in space and time. Furthermore, some detailed studies concerning site-formation processes and the quality of open-air sites (sedimentary development, paleoecology, multilayering, reworking, human impact on soils and sediments) are being conducted at selected localities. Recent investigations of the loess-paleosol sequences (LPS) in SE Europe provided important environmental information which differ from "classical" ecological approaches derived from other European loess provinces. New luminescence dating results provide a sensitive chronology of environmental changes recorded in the LPS from both upland and lowland positions, giving the potential to link these.

  17. Suspended-sediment loads, reservoir sediment trap efficiency, and upstream and downstream channel stability for Kanopolis and Tuttle Creek Lakes, Kansas, 2008-10

    Science.gov (United States)

    Juracek, Kyle E.

    2011-01-01

    Continuous streamflow and turbidity data collected from October 1, 2008, to September 30, 2010, at streamgage sites upstream and downstream from Kanopolis and Tuttle Creek Lakes, Kansas, were used to compute the total suspended-sediment load delivered to and released from each reservoir as well as the sediment trap efficiency for each reservoir. Ongoing sedimentation is decreasing the ability of the reservoirs to serve several purposes including flood control, water supply, and recreation. River channel stability upstream and downstream from the reservoirs was assessed using historical streamgage information. For Kanopolis Lake, the total 2-year inflow suspended-sediment load was computed to be 600 million pounds. Most of the suspended-sediment load was delivered during short-term, high-discharge periods. The total 2-year outflow suspended-sediment load was computed to be 31 million pounds. Sediment trap efficiency for the reservoir was estimated to be 95 percent. The mean annual suspended-sediment yield from the upstream basin was estimated to be 129,000 pounds per square mile per year. No pronounced changes in channel width were evident at five streamgage sites located upstream from the reservoir. At the Ellsworth streamgage site, located upstream from the reservoir, long-term channel-bed aggradation was followed by a period of stability. Current (2010) conditions at five streamgages located upstream from the reservoir were typified by channel-bed stability. At the Langley streamgage site, located immediately downstream from the reservoir, the channel bed degraded 6.15 feet from 1948 to 2010. For Tuttle Creek Lake, the total 2-year inflow suspended-sediment load was computed to be 13.3 billion pounds. Most of the suspended-sediment load was delivered during short-term, high-discharge periods. The total 2-year outflow suspended-sediment load was computed to be 327 million pounds. Sediment trap efficiency for the reservoir was estimated to be 98 percent. The mean

  18. Sediment processes modelling below hydraulic mining: towards environmental impact mitigation

    Science.gov (United States)

    Chalov, Sergey R.

    2010-05-01

    their nearness determines the water mass increase inside mining site. The predictive models were suggested to assess each of the mane-made processes contribution into the total sediment budget of the rivers below mining sites. The empirical data and theoretical and laboratory-derived correlations were used to obtain the predictive models for each processes of sediment supply. It was challenging to estimate specific erosion rate of washed exposed hillsides, channel incision, water supply conditions. Climatic and anthropogenic changes of water runoff also were simulated to decrease uncertainty of the proposed model. Application of the given approach to the hydraulic platinum-mining located in the Kamchatka peninsula (Koryak plateau, tributaries of the Vivenka River) gave the sediment budget of the placer-mined rivers and the total sediment yield supplied into the ocean from river basin. Polluted placer-mined rivers contribute about 30 % of the whole sediment yield of the Vivenka River. At the same time the catchment area of these rivers is less than 0,03 % from the whole Vivenka catchment area. Based on the sediment transport modeling the decision making system for controlling water pollution and stream community preservation was developed. Due to exposed hillside erosion prevention and settling pond system optimization the total decrease of sediment yield was up to 75 %.

  19. Characterization of the geology, geochemistry, and microbiology of the radio frequency heating demonstration site at the Savannah River Site

    International Nuclear Information System (INIS)

    Eddy Dilek, C.A.; Jarosch, T.R.; Fliermans, C.B.; Looney, B.B.; Parker, W.H.

    1993-08-01

    The overall objective of the Integrated Demonstration Project for the Remediation of Organics at Nonarid Sites at the Savannah River Site (SRS) is to evaluate innovative remediation, characterization, and monitoring systems to facilitate restoration of contaminated sites. The first phase of the demonstration focused on the application and development of in situ air stripping technologies to remediate sediments and groundwater contaminated with volatile organic compounds (VOCs). The second phase focused on the enhancement of the in situ air stripping process by adding selected nutrients to stimulate naturally occurring microorganisms that degrade VOCs. The purpose of the third phase was to evaluate the use of heating technologies [radio frequency (rf) and ohmic heating] to enhance the removal of contamination from clay layers where mass transfer is limited. The objective of this report is to document pretest and post-test data collected in support of the rf heating demonstration. The following data are discussed in this report: (1) a general description of the site including piezometers and sensors installed to monitor the remedial process; (2) stratigraphy, lithology, and a detailed geologic cross section of the study site; (3) tabulations of pretest and post-test moisture and VOC content of the sediments; (4) sampling and analysis procedures for sediment samples; (5) microbial abundance and diversity; (6) three-dimensional images of pretest and post-test contaminant distribution; (7) volumetric calculations

  20. Equilibrium Sampling to Determine the Thermodynamic Potential for Bioaccumulation of Persistent Organic Pollutants from Sediment

    DEFF Research Database (Denmark)

    Jahnke, Annika; MacLeod, Matthew; Wickström, Håkan

    2014-01-01

    Equilibrium partitioning (EqP) theory is currently the most widely used approach for linking sediment pollution by persistent hydrophobic organic chemicals to bioaccumulation. Most applications of the EqP approach assume (I) a generic relationship between organic carbon-normalized chemical...... chemical concentrations in the silicone, and applying lipid/silicone partition ratios to yield concentrations in lipid at thermodynamic equilibrium with the sediment (CLip⇌Sed). Furthermore, we evaluated the validity of assumption II by comparing CLip⇌Sed of selected persistent, bioaccumulative and toxic...... organic chemicals from sediment useful to prioritize management actions to remediate contaminated sites....

  1. Development and application of a sediment toxicity test using the benthic cladoceran Chydorus sphaericus

    International Nuclear Information System (INIS)

    Dekker, T.; Greve, G.D.; Ter Laak, T.L.; Boivin, M.E.; Veuger, B.; Gortzak, G.; Dumfries, S.; Luecker, S.M.G.; Kraak, M.H.S.; Admiraal, W.; Geest, H.G. van der

    2006-01-01

    This study reports on the development and application of a whole sediment toxicity test using a benthic cladoceran Chydorus sphaericus, as an alternative for the use of pelagic daphnids. A C. sphaericus laboratory culture was started and its performance under control conditions was optimised. The test was firstly validated by determining dose-response relationships for aqueous cadmium and copper and ammonia, showing a sensitivity of C. sphaericus (96 h LC 5 values of 594 μg Cd/L, 191 μg Cu/L and 46 mg ammonia/L at pH 8) similar to that of daphnids. Next, sediment was introduced into the test system and a series of contaminated sediments from polluted locations were tested. A significant negative correlation between survival and toxicant concentrations was observed. It is concluded that the test developed in the present study using the benthic cladoceran C. sphaericus is suitable for routine laboratory sediment toxicity testing. - A test was developed for assaying sediment toxicity using a commonly occurring small-bodied cladoceran

  2. Analysis of heavy metals in road-deposited sediments.

    Science.gov (United States)

    Herngren, Lars; Goonetilleke, Ashantha; Ayoko, Godwin A

    2006-07-07

    Road-deposited sediments were analysed for heavy metal concentrations at three different landuses (residential, industrial, commercial) in Queensland State, Australia. The sediments were collected using a domestic vacuum cleaner which was proven to be highly efficient in collecting sub-micron particles. Five particle sizes were analysed separately for eight heavy metal elements (Zn, Fe, Pb, Cd, Cu, Cr, Al and Mn). At all sites, the maximum concentration of the heavy metals occurred in the 0.45-75 microm particle size range, which conventional street cleaning services do not remove efficiently. Multicriteria decision making methods (MCDM), PROMETHEE and GAIA, were employed in the data analysis. PROMETHEE, a non-parametric ranking analysis procedure, was used to rank the metal contents of the sediments sampled at each site. The most polluted site and particle size range were the industrial site and the 0.45-75 microm range, respectively. Although the industrial site displayed the highest metal concentrations, the highest heavy metal loading coincided with the highest sediment load, which occurred at the commercial site. GAIA, a special form of principal component analysis, was applied to determine correlations between the heavy metals and particle size ranges and also to assess possible correlation with total organic carbon (TOC). The GAIA-planes revealed that irrespective of the site, most of the heavy metals are adsorbed to sediments below 150 microm. A weak correlation was found between Zn, Mn and TOC at the commercial site. This could lead to higher bioavailability of these metals through complexation reactions with the organic species in the sediments.

  3. Application of a surface complexation model to the interactions of Pu and Am with Esk Estuary sediments

    International Nuclear Information System (INIS)

    Turner, D.R.; Knox, S.; Titley, J.G.; Hamilton-Taylor, J.; Kelly, M.; Williams, G.

    1990-10-01

    Previous work has shown that Pu is remobilised from Esk sediments at low salinities of overlying water. A constant capacitance surface complexation model has been developed in order to understand and model the chemical processes occurring. The model is based on detailed chemical characterisation of sediment samples from the estuary. The following measurements were carried out to provide input parameters for the model: specific surface area; total surface sites (tritium exchange); proton and major ion exchange (potentiometric titration); and actinide (Pu and Am) partition coefficient as a function of pH and salinity at sediment and actinide concentrations typical of the Esk. (author)

  4. Assessing the environmental availability of uranium in soils and sediments

    Energy Technology Data Exchange (ETDEWEB)

    Amonette, J.E.; Holdren, G.R. Jr.; Krupa, K.M.; Lindenmeier, C.W. [Pacific Northwest Lab., Richland, WA (United States)

    1994-06-01

    Soils and sediments contaminated with uranium pose certain environmental and ecological risks. At low to moderate levels of contamination, the magnitude of these risks depends not only on the absolute concentrations of uranium in the material but also on the availability of the uranium to drinking water supplies, plants, or higher organisms. Rational approaches for regulating the clean-up of sites contaminated with uranium, therefore, should consider the value of assessing the environmental availability of uranium at the site before making decisions regarding remediation. The purpose of this work is to review existing approaches and procedures to determine their potential applicability for assessing the environmental availability of uranium in bulk soils or sediments. In addition to making the recommendations regarding methodology, the authors have tabulated data from the literature on the aqueous complexes of uranium and major uranium minerals, examined the possibility of predicting environmental availability of uranium based on thermodynamic solubility data, and compiled a representative list of analytical laboratories capable of performing environmental analyses of uranium in soils and sediments.

  5. Assessing the environmental availability of uranium in soils and sediments

    International Nuclear Information System (INIS)

    Amonette, J.E.; Holdren, G.R. Jr.; Krupa, K.M.; Lindenmeier, C.W.

    1994-06-01

    Soils and sediments contaminated with uranium pose certain environmental and ecological risks. At low to moderate levels of contamination, the magnitude of these risks depends not only on the absolute concentrations of uranium in the material but also on the availability of the uranium to drinking water supplies, plants, or higher organisms. Rational approaches for regulating the clean-up of sites contaminated with uranium, therefore, should consider the value of assessing the environmental availability of uranium at the site before making decisions regarding remediation. The purpose of this work is to review existing approaches and procedures to determine their potential applicability for assessing the environmental availability of uranium in bulk soils or sediments. In addition to making the recommendations regarding methodology, the authors have tabulated data from the literature on the aqueous complexes of uranium and major uranium minerals, examined the possibility of predicting environmental availability of uranium based on thermodynamic solubility data, and compiled a representative list of analytical laboratories capable of performing environmental analyses of uranium in soils and sediments

  6. Dilution of 210Pb by organic sedimentation in lakes of different trophic states, and application to studies of sediment-water interactions

    International Nuclear Information System (INIS)

    Binford, M.W.; Brenner, M.

    1986-01-01

    Lake sediments reflect conditions in the water column and can be used for rapid, integrative measurements of limnological variables. Examination of 210 Pb-dated cores from 12 Florida lakes of widely differing trophic state (expressed as Carlson's trophic state index: TSI) shows that net accumulation rate of organic matter is related to primary productivity in the water column. In 26 other lakes the activity of unsupported 210 Pb g -1 organic matter in surficial sediments is inversely related to trophic state and, therefore, to organic accumulation rate. From this observation, the authors develop a new method that uses fallout 210 Pb as a dilution tracer to calculate net sedimentary accumulation rates of any material in surface mud. They demonstrate strong relationships between net loss rate of biologically important materials (C, N, P, and pigments) and their respective water concentrations (expressed as TSI). Multiple regression models incorporating net sediment accumulation rates of all four variables explain up to 70% of the lake-to-lake variation of TSI. The 210 Pb-dilution method has application for studies for material cycling, paleolimnology, and sediment accumulation processes

  7. Assessment of sediment quality in dredged and undredged areas of the Trenton Channel of the Detroit River, Michigan USA, using the sediment quality triad

    Science.gov (United States)

    Besser, John M.; Giesy, John P.; Kubitz, Jody A.; Verbrugge, David A.; Coon, Thomas G.; Braselton, W. Emmett

    1996-01-01

    The “sediment quality triad” approach was used to assess the effects of dredging on the sediment quality of a new marina in the Trenton Channel of the Detroit River, and to evaluate spatial and temporal variation in sediment quality in the Trenton Channel. Samples were collected in November of 1993 (10 months after dredging) and characterized by chemical analysis, sediment bioassays, and assessment of benthic invertebrate communities. The three study components indicated little difference in sediment quality at dredged sites in the marina relative to nearby areas in the Trenton Channel, and little change in sediment quality of Trenton Channel sites relative to conditions reported in the mid-1980s. These results suggest that improvement in sediment quality in the Trenton Channel, due to dredging or natural processes, will depend on elimination of sediment “hot spots” and other upstream contaminant sources. Concentrations of chemical contaminants, especially metals and polycyclic aromatic hydrocarbons, exceeded concentrations associated with effects on biota and were significantly correlated with results of sediment bioassays and characteristics of benthic communities. Laboratory sediment bioassays with Hyalella azteca andChironomus tentans produced better discrimination among sites with differing degrees of contamination than did characterization of benthic communities, which were dominated by oligochaetes at all sites in the marina and the Trenton Channel.

  8. Response of suspended sediment concentration to tidal dynamics at a site inside the mouth of an inlet: Jiaozhou Bay (China

    Directory of Open Access Journals (Sweden)

    S. L. Yang

    2004-01-01

    Full Text Available Observations of fair weather currents and suspended sediment concentrations (SSC were made using an acoustic Doppler current profiler and two YSI turbidity sensors over a neap to spring time cycle at a site near the inner mouth of a semi-enclosed mesotidal-macrotidal embayment (Jiaozhou Bay to examine the influence of tidal dynamics on concentration and transport of suspended sediment. During the investigation, SSC varied from about 3 to 16 mg L–1 at the surface and about 6 to 40 mg L–1 close to the bed, while the current velocity reached 79 cm s–1 at the surface and 61 cm s–1 near the bed. SSC was tidally cyclic. The near-bed instantaneous SSC was closely related to current velocity with almost no time lag, indicating that the variability of SSC was governed by current-induced settling/resuspension. At the surface, however, instantaneous SSC was poorly related to instantaneous current velocity because the peak SSC tended to occur around ebb slack water. This suggests that the surface SSC was controlled by horizontal advection from landward higher concentration areas. Both at the surface and near the bed, on the other hand, tidally-averaged SSC was well correlated to tidal range and current speed. Current velocity and SSC were flood-dominated for all the tides investigated, which resulted in significant landward residual suspended sediment transport at the study site. The observed flood dominance was mainly attributed to the location of the study site on the landward side of the bay’s inlet where flow separation is favoured during flood tide. It was concluded that tides are the dominant hydrodynamic component controlling the variability of SSC during fair weather at the study area. Keywords: sediment, concentration, suspension, advection, currents, shoalling effect, Jiaozhou Bay, China

  9. Evaluation through column leaching tests of metal release from contaminated estuarine sediment subject to CO2 leakages from Carbon Capture and Storage sites

    International Nuclear Information System (INIS)

    Payán, M. Cruz; Galan, Berta; Coz, Alberto; Vandecasteele, Carlo; Viguri, Javier R.

    2012-01-01

    The pH change and the release of organic matter and metals from sediment, due to the potential CO 2 acidified seawater leakages from a CCS (Carbon Capture and Storage) site are presented. Column leaching test is used to simulate a scenario where a flow of acidified seawater is in contact with recent contaminated sediment. The behavior of pH, dissolved organic carbon (DOC) and metals As, Cd, Cr, Cu, Ni, Pb, Zn, with liquid to solid (L/S) ratio and pH is analyzed. A stepwise strategy using empirical expressions and a geochemical model was conducted to fit experimental release concentrations. Despite the neutralization capacity of the seawater-carbonate rich sediment system, important acidification and releases are expected at local scale at lower pH. The obtained results would be relevant as a line of evidence input of CCS risk assessment, in an International context where strategies to mitigate the climate change would be applied. - Highlights: ► Tier structured approach for assessment of the release of metals from sediment. ► Standard column leaching test to simulate CO 2 acidified seawater CCS leakages. ► Metal and DOC release from marine sediment in contact to CO 2 acidified seawater. ► From empirical to geochemical modeling approaches of DOC and metals release in column tests. ► Contamination line of evidence input of CCS risk assessment. - Column metal release from CO 2 acidified seawater leakages in contact with estuarine contaminated sediment in CCS sites

  10. Heavy metals and hydrocarbon concentrations in water, sediments and tissue of Cyclope neritea from two sites in Suez Canal, Egypt and histopathological effects.

    Science.gov (United States)

    Sharaf, Hesham M; Shehata, Abdalla M

    2015-01-01

    Heavy metals and hydrocarbons are of the most common marine pollutants around the world. The present study aimed to assess the concentration of petroleum hydrocarbons and heavy metals in tissues of the snail cyclope neritea, water and sediments from two sites of the study area (Temsah lake and Suez canal) represent polluted and unpolluted sites respectively. The results showed that, the levels of the heavy metals (Pb, Cd, Co, Mg and Zn) in the polluted area have reached harmful limits recorded globally. Lead in water, sediment and tissue of the snail reached to 0.95 ppm, 4.54 ppm and 7.93 ppm respectively. Cadmium reached 0.31 ppm, 1.15 ppm and 3.08 ppm in the corresponding samples. Cobalt was not detected in water, but it reached 1.42 ppm and 10.36 ppm in the sediment and snails tissue respectively. Magnesium in water, sediment and tissue of the snail reached 3.73 ppm, 9.44 ppm and12.6 ppm respectively. Zinc reached 0.11 ppm, 3.89 ppm and 12.60ppm in the corresponding samples. Meanwhile, hydrocarbons in the polluted area (site1) reached 110.10 μg/L, 980.15 μg/g and 228.00 μg/g in water sediment and digestive gland tissues of the snails respectively. Whereas, hydrocarbons in the unpolluted area (site2) were estimated as 14.20 μg/L, 55.60 μg/g and 22.66 μg/g in water, sediment and tissue of the snails respectively. The combination of histopathological image with monitoring of the metal level in the digestive gland of the present snail provides an important tool for early detection of impending environmental problems and potential public health issues. Petroleum hydrocarbons are toxic to the marine fauna when present above certain limit in the marine water. The major detoxification organ in molluscs is the digestive gland, which has been used as a bioindicator organ for toxicity assessment. The effect of high crude oil on the digestive gland tubules of exposed snails when examined microscopically reveals a series of histological changes which indicates that the

  11. Early Site Permit Demonstration Program: Siting Guide, Site selection and evaluation criteria for an early site permit application. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    1993-03-24

    In August 1991, the Joint Contractors came to agreement with Sandia National Laboratories (SNL) and the Department of Energy (DOE) on a workscope for the cost-shared Early Site Permit Demonstration Program. One task within the scope was the development of a guide for site selection criteria and procedures. A generic Siting Guide his been prepared that is a roadmap and tool for applicants to use developing detailed siting plans for their specific region of the country. The guide presents three fundamental principles that, if used, ensure a high degree of success for an ESP applicant. First, the site selection process should take into consideration environmentally diverse site locations within a given region of interest. Second, the process should contain appropriate opportunities for input from the public. Third, the process should be applied so that it is clearly reasonable to an impartial observer, based on appropriately selected criteria, including criteria which demonstrate that the site can host an advanced light water reactor (ALWR). The Siting Guide provides for a systematic, comprehensive site selection process in which three basic types of criteria (exclusionary, avoidance, and suitability) are presented via a four-step procedure. It provides a check list of the criteria for each one of these steps. Criteria are applied qualitatively, as well as presented numerically, within the guide. The applicant should use the generic guide as an exhaustive checklist, customizing the guide to his individual situation.

  12. Multi-residues analysis of pre-emergence herbicides in fluvial sediments: application to the mid-Garonne River.

    Science.gov (United States)

    Devault, Damien A; Merlina, Georges; Lim, Puy; Probst, Jean-Luc; Pinelli, Eric

    2007-09-01

    Contamination of man and ecosystems by pesticides has become a major environmental concern. Whereas many studies exist on contamination from agriculture, the effects of urban sources are usually omitted. Fluvial sediment is a complex matrix of pollutants but little is known of its recent herbicide content. This study proposes a method for a fast and reliable analysis of herbicides by employing the accelerated solvent extractor (ASE). The aim of the study is to show the impact of a major town (Toulouse) on the herbicide content in the river. In this study, three herbicide families (i.e.s-triazine, substituted ureas and anilides) were analysed in fluvial sediment fractions at 11 sampling sites along the mid-Garonne River and its tributaries. River water contamination by herbicides is minor, except for at three sites located in urban areas. Among the herbicidal families studied, urban and suburban areas are distinguished from rural areas and were found to be the most contaminated sites during the study period, a winter low-water event. The herbicide content of the coarse sediment fractions is about one third of that found in the fine fractions and usually ignored. The distribution of pesticide concentrations across the whole range of particle sizes was investigated to clarify the role of plant remains on the significant accumulation in the coarse fractions.

  13. LIBRA: LIgand Binding site Recognition Application.

    Science.gov (United States)

    Hung, Le Viet; Caprari, Silvia; Bizai, Massimiliano; Toti, Daniele; Polticelli, Fabio

    2015-12-15

    In recent years, structural genomics and ab initio molecular modeling activities are leading to the availability of a large number of structural models of proteins whose biochemical function is not known. The aim of this study was the development of a novel software tool that, given a protein's structural model, predicts the presence and identity of active sites and/or ligand binding sites. The algorithm implemented by ligand binding site recognition application (LIBRA) is based on a graph theory approach to find the largest subset of similar residues between an input protein and a collection of known functional sites. The algorithm makes use of two predefined databases for active sites and ligand binding sites, respectively, derived from the Catalytic Site Atlas and the Protein Data Bank. Tests indicate that LIBRA is able to identify the correct binding/active site in 90% of the cases analyzed, 90% of which feature the identified site as ranking first. As far as ligand binding site recognition is concerned, LIBRA outperforms other structure-based ligand binding sites detection tools with which it has been compared. The application, developed in Java SE 7 with a Swing GUI embedding a JMol applet, can be run on any OS equipped with a suitable Java Virtual Machine (JVM), and is available at the following URL: http://www.computationalbiology.it/software/LIBRAv1.zip. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  14. Mercury pollution in the lake sediments and catchment soils of anthropogenically-disturbed sites across England.

    Science.gov (United States)

    Yang, Handong; Turner, Simon; Rose, Neil L

    2016-12-01

    Sediment cores and soil samples were taken from nine lakes and their catchments across England with varying degrees of direct human disturbance. Mercury (Hg) analysis demonstrated a range of impacts, many from local sources, resulting from differing historical and contemporary site usage and management. Lakes located in industrially important areas showed clear evidence for early Hg pollution with concentrations in sediments reaching 400-1600 ng g -1 prior to the mid-19th century. Control of inputs resulting from local management practices and a greater than 90% reduction in UK Hg emissions since 1970 were reflected by reduced Hg pollution in some lakes. However, having been a sink for Hg deposition for centuries, polluted catchment soils are now the major Hg source for most lakes and consequently recovery from reduced Hg deposition is being delayed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Multi-Elements in Waters and Sediments of Shallow Lakes: Relationships with Water, Sediment, and Watershed Characteristics.

    Science.gov (United States)

    Kissoon, La Toya T; Jacob, Donna L; Hanson, Mark A; Herwig, Brian R; Bowe, Shane E; Otte, Marinus L

    2015-06-01

    We measured concentrations of multiple elements, including rare earth elements, in waters and sediments of 38 shallow lakes of varying turbidity and macrophyte cover in the Prairie Parkland (PP) and Laurentian Mixed Forest (LMF) provinces of Minnesota. PP shallow lakes had higher element concentrations in waters and sediments compared to LMF sites. Redundancy analysis indicated that a combination of site- and watershed-scale features explained a large proportion of among-lake variability in element concentrations in lake water and sediments. Percent woodland cover in watersheds, turbidity, open water area, and macrophyte cover collectively explained 65.2 % of variation in element concentrations in lake waters. Sediment fraction smaller than 63 µm, percent woodland in watersheds, open water area, and sediment organic matter collectively explained 64.2 % of variation in element concentrations in lake sediments. In contrast to earlier work on shallow lakes, our results showed the extent to which multiple elements in shallow lake waters and sediments were influenced by a combination of variables including sediment characteristics, lake morphology, and percent land cover in watersheds. These results are informative because they help illustrate the extent of functional connectivity between shallow lakes and adjacent lands within these lake watersheds.

  16. Deciphering Equatorial Pacific Deep Sea Sediment Transport Regimes by Core-Log-Seismic Integration

    Science.gov (United States)

    Ortiz, E.; Tominaga, M.; Marcantonio, F.

    2017-12-01

    Investigating deep-sea sediment transportation and deposition regimes is a key to accurately understand implications from geological information recorded by pelagic sediments, e.g. climate signals. However, except for physical oceanographic particle trap experiments, geochemical analyses of in situsediments, and theoretical modeling of the relation between the bottom currents and sediment particle flux, it has remained a challenging task to document the movement of deep sea sediments, that takes place over time. We utilized high-resolution, multichannel reflection seismic data from the eastern equatorial Pacific region with drilling and logging results from two Integrated Ocean Drilling Program (IODP) sites, the Pacific Equatorial Age Transect (PEAT) 7 (Site U1337) and 8 (Site U1338), to characterize sediment transportation regimes on 18-24 Ma oceanic crust. Site U1337, constructed by a series of distinct abyssal hills and abyssal basins; Site U1338, located 570 km SE from Site U1337 site and constructed by a series of ridges, seamounts, and abyssal hills. These sites are of particular interest due to their proximity to the equatorial productivity zone, areas with high sedimentation rates and preservation of carbonate-bearing sediment that provide invaluable insights on equatorial Pacific ecosystems and carbon cycle. We integrate downhole geophysical logging data as well as geochemistry and physical properties measurements on recovered cores from IODP Sites U1337 and U1338 to comprehensively examine the mobility of deep-sea sediments and sediment diagenesis over times in a quasi-3D manner. We also examine 1100 km of high resolution underway seismic surveys from site survey lines in between PEAT 7 and 8 in order to investigate changes in sediment transportation between both sites. Integrating detailed seismic interpretations, high resolution core data, and 230Th flux measurements we aim to create a detailed chronological sedimentation and sediment diagenesis history

  17. Mixture design and treatment methods for recycling contaminated sediment

    International Nuclear Information System (INIS)

    Wang, Lei; Kwok, June S.H.; Tsang, Daniel C.W.; Poon, Chi-Sun

    2015-01-01

    Graphical abstract: - Highlights: • Contaminated sediment can be recycled as fill material for site formation. • Thermal pretreatment of sediment permits non-load-bearing block application. • CO 2 curing enhances strength and reduces carbon footprint. • Inclusion of granular wastes reinforces the solidified sediment matrix. • Sediment blocks are useful resources for construction use. - Abstract: Conventional marine disposal of contaminated sediment presents significant financial and environmental burden. This study aimed to recycle the contaminated sediment by assessing the roles and integration of binder formulation, sediment pretreatment, curing method, and waste inclusion in stabilization/solidification. The results demonstrated that the 28-d compressive strength of sediment blocks produced with coal fly ash and lime partially replacing cement at a binder-to-sediment ratio of 3:7 could be used as fill materials for construction. The X-ray diffraction analysis revealed that hydration products (calcium hydroxide) were difficult to form at high sediment content. Thermal pretreatment of sediment removed 90% of indigenous organic matter, significantly increased the compressive strength, and enabled reuse as non-load-bearing masonry units. Besides, 2-h CO 2 curing accelerated early-stage carbonation inside the porous structure, sequestered 5.6% of CO 2 (by weight) in the sediment blocks, and acquired strength comparable to 7-d curing. Thermogravimetric analysis indicated substantial weight loss corresponding to decomposition of poorly and well crystalline calcium carbonate. Moreover, partial replacement of contaminated sediment by various granular waste materials notably augmented the strength of sediment blocks. The metal leachability of sediment blocks was minimal and acceptable for reuse. These results suggest that contaminated sediment should be viewed as useful resources

  18. Mixture design and treatment methods for recycling contaminated sediment

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lei; Kwok, June S.H.; Tsang, Daniel C.W., E-mail: dan.tsang@polyu.edu.hk; Poon, Chi-Sun

    2015-02-11

    Graphical abstract: - Highlights: • Contaminated sediment can be recycled as fill material for site formation. • Thermal pretreatment of sediment permits non-load-bearing block application. • CO{sub 2} curing enhances strength and reduces carbon footprint. • Inclusion of granular wastes reinforces the solidified sediment matrix. • Sediment blocks are useful resources for construction use. - Abstract: Conventional marine disposal of contaminated sediment presents significant financial and environmental burden. This study aimed to recycle the contaminated sediment by assessing the roles and integration of binder formulation, sediment pretreatment, curing method, and waste inclusion in stabilization/solidification. The results demonstrated that the 28-d compressive strength of sediment blocks produced with coal fly ash and lime partially replacing cement at a binder-to-sediment ratio of 3:7 could be used as fill materials for construction. The X-ray diffraction analysis revealed that hydration products (calcium hydroxide) were difficult to form at high sediment content. Thermal pretreatment of sediment removed 90% of indigenous organic matter, significantly increased the compressive strength, and enabled reuse as non-load-bearing masonry units. Besides, 2-h CO{sub 2} curing accelerated early-stage carbonation inside the porous structure, sequestered 5.6% of CO{sub 2} (by weight) in the sediment blocks, and acquired strength comparable to 7-d curing. Thermogravimetric analysis indicated substantial weight loss corresponding to decomposition of poorly and well crystalline calcium carbonate. Moreover, partial replacement of contaminated sediment by various granular waste materials notably augmented the strength of sediment blocks. The metal leachability of sediment blocks was minimal and acceptable for reuse. These results suggest that contaminated sediment should be viewed as useful resources.

  19. Energy Gradients Structure Microbial Communities Across Sediment Horizons in Deep Marine Sediments of the South China Sea

    Science.gov (United States)

    Graw, Michael F.; D'Angelo, Grace; Borchers, Matthew; Thurber, Andrew R.; Johnson, Joel E.; Zhang, Chuanlun; Liu, Haodong; Colwell, Frederick S.

    2018-01-01

    The deep marine subsurface is a heterogeneous environment in which the assembly of microbial communities is thought to be controlled by a combination of organic matter deposition, electron acceptor availability, and sedimentology. However, the relative importance of these factors in structuring microbial communities in marine sediments remains unclear. The South China Sea (SCS) experiences significant variability in sedimentation across the basin and features discrete changes in sedimentology as a result of episodic deposition of turbidites and volcanic ashes within lithogenic clays and siliceous or calcareous ooze deposits throughout the basin's history. Deep subsurface microbial communities were recently sampled by the International Ocean Discovery Program (IODP) at three locations in the SCS with sedimentation rates of 5, 12, and 20 cm per thousand years. Here, we used Illumina sequencing of the 16S ribosomal RNA gene to characterize deep subsurface microbial communities from distinct sediment types at these sites. Communities across all sites were dominated by several poorly characterized taxa implicated in organic matter degradation, including Atribacteria, Dehalococcoidia, and Aerophobetes. Sulfate-reducing bacteria comprised only 4% of the community across sulfate-bearing sediments from multiple cores and did not change in abundance in sediments from the methanogenic zone at the site with the lowest sedimentation rate. Microbial communities were significantly structured by sediment age and the availability of sulfate as an electron acceptor in pore waters. However, microbial communities demonstrated no partitioning based on the sediment type they inhabited. These results indicate that microbial communities in the SCS are structured by the availability of electron donors and acceptors rather than sedimentological characteristics. PMID:29696012

  20. Lacustrine sedimentation in an altitude forest site, central Andes, Bolivia. Palaeo-climatic implications

    International Nuclear Information System (INIS)

    Sifeddine, A.; Bertaux, J.; Mourguiart, Ph.; Disnar, J.R.; Laggoun-Defarge, F.; Argollo, J.

    1998-01-01

    A sedimentological study of a 755 cm length core sampled in the middle of a marshy depression surrounded by a cloud forest in the central Andes reveals that this site has recorded important environmental variations during the last 50 000 years. For the most part (625 cm) the core is composed of detrital rich sediments deposited during the Upper Pleistocene. The highest amount of detrital influx underlines the Last Glacial Maximum which ranges from ca 29,000 14 C yr B.P. to ca 16,000 14 C yr B.P. (ca 18,500 cal yr B.P.), between two relatively humid phases. The sedimentation of the present Interglacial, starting at ca 12,500 14 C yr B.P. (14,500 cal yr B.P.), is mainly organic, as a consequence of the great development of soils and the forest vegetal cover the catchment area. The maximum extension of this vegetal cover ranging from 12,500 to ca 10,500 14 C yr B.P. (14,500 and 12,400 cal yr B.P.) is followed from 10,500 to 8,000 14 C yr B.P. (12,400 and 8,800 cal yr B.P.) by a drier period is revealed by the occurrence of micro-charcoals in the sediment. Between ca 8,000 and 4,000 14 C yr B.P. (8,800 and 4,500 cal yr B.P.), the sharp increase of micro-charcoals content, likely related to palaeo-fires, underlines an intensification of this dry trend. (authors)

  1. Metal assessment in sediments from the Guarapiranga Reservoir

    International Nuclear Information System (INIS)

    Coutinho, Suellen N.; Figueiredo, Ana Maria G.; Quináglia, Gilson A.

    2017-01-01

    The study of the distribution of metals in sediments is very important from the point of view of environmental pollution once the sediment concentrates metals in aquatic systems and represents a relevant contamination monitor. The analysis of sediments has been used to evaluate the quality of aquatic systems in relation to the concentration of metals. This study aimed to assess sediment contamination by metals in the Guarapiranga Reservoir. Sediment and water samples were analyzed by ICP OES (Inductively Coupled Plasma Optical Emission Spectrometry) for As, Cd, Cr, Cu, Ni, Pb and Zn and by CV AAS (Cold Vapor Atomic Absorption Spectrophotometry) for Hg. The sediment samples results were compared to TEL (Threshold Effect Level) and PEL (Probable Effect Level) guidance values and RRV (Reference Regional Values). Geoaccumulation Index (I geo ) was calculated to evaluate metals pollution degree using reference values established for metals and metalloids in sediments from the Upper Tietê Basin and E H -pH diagrams were applied to explain chemical forms and bioavailability of toxic metals in sediment samples. In general, most of the analyzed elements exceeded TEL values and Cr, Cu and Zn exceeded RRV guidelines. The high concentrations of Cu found in this reservoir can be explained by the frequent application of CuSO 4 algicide, mainly at sampling site S-03. The I geo indicated moderated polluted sediments by Zn and moderately to extremely polluted sediments by Cu, especially at S-03, in agreement with the TEL, PEL and RRV values comparison. These results may indicate potential risk of the reservoir water quality. (author)

  2. Maywood Interim Storage Site annual environmental report for calendar year 1991, Maywood, New Jersey. [Maywood Interim Storage Site

    Energy Technology Data Exchange (ETDEWEB)

    None

    1992-09-01

    This document describes the environmental monitoring program at the Maywood Interim Storage Site (MISS) and surrounding area, implementation of the program, and monitoring results for 1991. Environmental monitoring of MISS began in 1984 when congress added the site to the US Department of Energy's (DOE) Formerly Utilized Sites Remedial Action Program (FUSRAP). FUSRAP is a DOE program to identify and decontaminate or otherwise control sites where residual radioactive materials remain from the early years of the nation's atomic energy program or from commercial operations causing conditions that Congress has authorized DOE to remedy. The environmental monitoring program at MISS includes sampling networks for radon and thoron concentrations in air; external gamma radiation-exposure; and total uranium, radium-226, radium-228, thorium-232, and thorium-230 concentrations in surface water, sediment, and groundwater. Additionally, several nonradiological parameters are measured in surface water, sediment, and groundwater. Monitoring results are compared with applicable Environmental Protection Agency standards, DOE derived concentration guides (DCGs), dose limits, and other requirements in DOE orders. Environmental standards are established to protect public health and the environment.

  3. Needles 10 x 20 NTMS area, California and Arizona, data report (abbreviated). National uranium resource evaluation program: hydrogeochemical and stream sediment reconnaissance

    International Nuclear Information System (INIS)

    Cook, J.R.

    1981-05-01

    Surface sediment samples were collected at 1672 sites, at a target sampling density of one site per 13 square kilometers. Ground water samples were collected at 49 sites. Neutron activation analysis results are given for uranium and 16 other elements in sediments, and for uranium and 9 other elements in ground water. Mass spectrometry results are given for helium in ground water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Data from ground water sites include (1) water chemistry measurements (pH, conductivity, and alkalinity), (2) physical measurements where applicable (water temperature, well description, and scintillometer reading), and (3) elemental analyses (U, Al, Br, Cl, Dy, F, Mg, Mn, Na, and V). Helium analyses are given for ground water. Data from sediment sites include (1) stream water chemistry measurements from sites where water was available and (2) elemental analyses for sediment samples (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Samples site descriptors (stream characteristics, vegetation, etc.) are also tabulated. Areal distribution maps, histograms, and cumulative frequency plots for most elements; U/Th, U/Hf, U/(Th + Hf), and U/La ratios; and scintillometer readings at sediment sample sites are included on the microfiche. Uranium concentrations in the sediments which were above limits ranged from 0.10 to 33.90 ppM. The mean of the logarithms of the uranium concentrations was 0.52. Clusters of uranium values greater than 10 ppM occur in quadrangles AH, BH, and DA

  4. Microbial Transport, Survival, and Succession in a Sequence of Buried Sediments

    International Nuclear Information System (INIS)

    Kieft, T.L.; Murphy, E.M.; Haldeman, D.L.; Amy, P.S.; Bjornstad, B.N.; McDonald, E.V.; Ringelberg, D.B.; White, D.C.; Stair, J.; Griffiths, R.P.; Gsell, T.C.; Holben, W.E.; Boone, D.R.

    1995-01-01

    Two chronosequence of unsaturated buried loess sediments ranging in age from and lt;10,000 years to and gt;1 million years were investigated to reconstruct patterns of microbial ecological succession that have occurred since sediment burial. The relative importance of microbial transport and survival to succession were inferred from sediment ages, porewater ages, patterns of abundance (measured by direct counts, counts of culturable cells, and total phospholipid fatty acids), activities (measured by radiotracer and enzyme assays), and community composition (measured by phospholipid fatty acid patterns and Biolog substrate usage). Samples were collected by coring at two sites 40 km apart in the Palouse region of eastern Washington State near the towns of Washtucna and Winona. The Washtucna site was flooded multiple times during the Pleistocene by glacial outburst floods; the elevation of the Winona site is above flood stage. Sediments at the Washtucna site were collected from near surface to 14.9 m depth, where the sediment age was(approx)250 ka and the porewater age was 3700 years; sample intervals at the Winona site ranged from near surface to 38 m (sediment age:(approx)1 Ma; porewater age: 1200 years). Microbial abundance and activities declined with depth at both sites; however, even the deepest, oldest sediments showed evidence of viable microorganisms. Sediments of equivalent age had equal quantities of microorganisms, but differing community types. Differences in community make-up between the two sites can be attributed to differences in groundwater recharge and paleoflooding. Estimates of the ages of the microbial communities can be constrained by porewater and sediment ages. In the shallower sediments ( and lt;9 m at Washtucna, and lt;12 m at Winona), the microbial communities are likely similar in age to the groundwater; thus, microbial succession has been influenced by recent transport of microorganisms from the surface. In the deeper sediments, the

  5. Microbial Transport, Survival, and Succession in a Sequence of Buried Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Kieft, T.L.; Murphy, E.M.; Haldeman, D.L.; Amy, P.S.; Bjornstad, B.N.; McDonald, E.V.; Ringelberg, D.B.; White, D.C.; Stair, J.; Griffiths, R.P.; Gsell, T.C.; Holben, W.E.; Boone, D.R.

    1995-01-05

    Two chronosequence of unsaturated buried loess sediments ranging in age from <10,000 years to >1 million years were investigated to reconstruct patterns of microbial ecological succession that have occurred since sediment burial. The relative importance of microbial transport and survival to succession were inferred from sediment ages, porewater ages, patterns of abundance (measured by direct counts, counts of culturable cells, and total phospholipid fatty acids), activities (measured by radiotracer and enzyme assays), and community composition (measured by phospholipid fatty acid patterns and Biolog substrate usage). Samples were collected by coring at two sites 40 km apart in the Palouse region of eastern Washington State near the towns of Washtucna and Winona. The Washtucna site was flooded multiple times during the Pleistocene by glacial outburst floods; the elevation of the Winona site is above flood stage. Sediments at the Washtucna site were collected from near surface to 14.9 m depth, where the sediment age was {approx}250 ka and the porewater age was 3700 years; sample intervals at the Winona site ranged from near surface to 38 m (sediment age: {approx}1 Ma; porewater age: 1200 years). Microbial abundance and activities declined with depth at both sites; however, even the deepest, oldest sediments showed evidence of viable microorganisms. Sediments of equivalent age had equal quantities of microorganisms, but differing community types. Differences in community make-up between the two sites can be attributed to differences in groundwater recharge and paleoflooding. Estimates of the ages of the microbial communities can be constrained by porewater and sediment ages. In the shallower sediments (<9 m at Washtucna, <12 m at Winona), the microbial communities are likely similar in age to the groundwater; thus, microbial succession has been influenced by recent transport of microorganisms from the surface. In the deeper sediments, the populations may be

  6. Controls of Sediment Nitrogen Dynamics in Tropical Coastal Lagoons

    Science.gov (United States)

    Enrich-Prast, Alex; Figueiredo, Viviane; Esteves, Francisco de Assis; Nielsen, Lars Peter

    2016-01-01

    Sediment denitrification rates seem to be lower in tropical environments than in temperate environments. Using the isotope pairing technique, we measured actual denitrification rates in the sediment of tropical coastal lagoons. To explain the low denitrification rates observed at all study sites (<5 μmol N2 m-2 h-1), we also evaluated potential oxygen (O2) consumption, potential nitrification, potential denitrification, potential anammox, and estimated dissimilatory nitrate (NO3-) reduction to ammonium (NH4+; DNRA) in the sediment. 15NO3- and 15NH4+ conversion was measured in oxic and anoxic slurries from the sediment surface. Sediment potential O2 consumption was used as a proxy for overall mineralization activity. Actual denitrification rates and different potential nitrogen (N) oxidation and reduction processes were significantly correlated with potential O2 consumption. The contribution of potential nitrification to total O2 consumption decreased from contributing 9% at sites with the lowest sediment mineralization rates to less than 0.1% at sites with the highest rates. NO3- reduction switched completely from potential denitrification to estimated DNRA. Ammonium oxidation and nitrite (NO2-) reduction by potential anammox contributed up to 3% in sediments with the lowest sediment mineralization rates. The majority of these patterns could be explained by variations in the microbial environments from stable and largely oxic conditions at low sediment mineralization sites to more variable conditions and the prevalences of anaerobic microorganisms at high sediment mineralization sites. Furthermore, the presence of algal and microbial mats on the sediment had a significant effect on all studied processes. We propose a theoretical model based on low and high sediment mineralization rates to explain the growth, activity, and distribution of microorganisms carrying out denitrification and DNRA in sediments that can explain the dominance or coexistence of DNRA and

  7. Sediment characteristics and wind-induced sediment dynamics in shallow Lake Markermeer, the Netherlands

    NARCIS (Netherlands)

    Kelderman, P.; Ang'weya, R.O.; De Rozari, P.; Vijverberg, T.

    2012-01-01

    In 2007/08, a study was undertaken on the sediment dynamics in shallow Lake Markermeer (the Netherlands). Firstly, sediment characteristics were determined at 49 sites in the lake. Parameters such as median grain size and loss on ignition showed a spatial as well as water depth related pattern,

  8. Mangrove sediment core analysis of foraminiferal assemblages - a study at two sites along the western coast of India

    Directory of Open Access Journals (Sweden)

    P. Vidya

    2014-02-01

    Full Text Available Mangroves are an unique habitat and are largely influenced by sea level changes and wave energy. Foraminifera (Protista preserved in mangrove sediments provide an excellent proxy for deducing past conditions. One meter deep mangrove core samples at two sites on the western coast of India were collected. The foraminiferal assemblages at various depths showed significant changes in the abundance and diversity down the cores. A total of 59 species belonging to 32 genera, 24 families and five suborders were identified from the cores of these two sites. The cores showed an abundance of genus Rotalidium particularly the species Rotalidium annectans. Other species identified include Ammonia, Elphidium, Nonion, Spiroloculina, Quinqueloculina, Globigerinoides, etc. The pH, organic matter and CaCO3 also showed variations down the cores. There was a lack of correlation between sediment characteristics and the abundance of foraminifera in the cores. The low diversity and differences in distribution of foraminifera compared to surface intertidal samples may be due to intense post depositional changes or anthropogenic disturbances. The mangrove ecology thus appears disturbed by various factors.

  9. Energy Gradients Structure Microbial Communities Across Sediment Horizons in Deep Marine Sediments of the South China Sea

    Directory of Open Access Journals (Sweden)

    Michael F. Graw

    2018-04-01

    Full Text Available The deep marine subsurface is a heterogeneous environment in which the assembly of microbial communities is thought to be controlled by a combination of organic matter deposition, electron acceptor availability, and sedimentology. However, the relative importance of these factors in structuring microbial communities in marine sediments remains unclear. The South China Sea (SCS experiences significant variability in sedimentation across the basin and features discrete changes in sedimentology as a result of episodic deposition of turbidites and volcanic ashes within lithogenic clays and siliceous or calcareous ooze deposits throughout the basin's history. Deep subsurface microbial communities were recently sampled by the International Ocean Discovery Program (IODP at three locations in the SCS with sedimentation rates of 5, 12, and 20 cm per thousand years. Here, we used Illumina sequencing of the 16S ribosomal RNA gene to characterize deep subsurface microbial communities from distinct sediment types at these sites. Communities across all sites were dominated by several poorly characterized taxa implicated in organic matter degradation, including Atribacteria, Dehalococcoidia, and Aerophobetes. Sulfate-reducing bacteria comprised only 4% of the community across sulfate-bearing sediments from multiple cores and did not change in abundance in sediments from the methanogenic zone at the site with the lowest sedimentation rate. Microbial communities were significantly structured by sediment age and the availability of sulfate as an electron acceptor in pore waters. However, microbial communities demonstrated no partitioning based on the sediment type they inhabited. These results indicate that microbial communities in the SCS are structured by the availability of electron donors and acceptors rather than sedimentological characteristics.

  10. Site remediation technologies and environmental management practices in the utility industry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Sessions covered: chemical oxidation; DNAPL and source management; regulatory perspectives and state programs; manufactured gas plant site management; sediments, cyanides, and other issues at MGP sites; biotechnology applications; agricultural waste issues; risk communication and bioremediation; air emissions and air toxics management; project management and redevelopment; environmentally acceptable endpoint and risk-based site management; site assessment, background concentration and closure; risk communication and beneficial use by recycling; PCB and RCRA issues; and phytoremediation and bioremediation of wastes.

  11. Sediment tracing by `customised' magnetic fingerprinting: from the sub-catchment to the ocean scale

    Science.gov (United States)

    Maher, B.

    2009-04-01

    Robust identification of catchment suspended sediment sources is a prerequisite both for understanding sediment delivery processes and targeting of effective mitigation measures. Fine sediment delivery can pose management problems, especially with regard to nutrient run-off and siltation of water courses and bodies. Suspended sediment load constitutes the dominant mode of particulate material loss from catchments but its transport is highly episodic. Identification of suspended sediment sources and fluxes is therefore a prerequisite both for understanding of fluvial geomorphic process and systems and for designing strategies to reduce sediment transport, delivery and yields. Here will be discussed sediment ‘fingerprinting', using the magnetic properties of soils and sediments to characterise sediment sources and transport pathways over a very wide variety of spatial scales, from Lake Bassenthwaite in the English Lake District to the Burdekin River in Queensland and even the North Atlantic Ocean during the last glacial maximum. The applicability of magnetic ‘fingerprinting' to such a range of scales and environments has been significantly improved recently through use of new and site-appropriate magnetic measurement techniques, statistical processing and sample treatment options.

  12. Elemental analysis of river sediments by PIXE and PIGE

    International Nuclear Information System (INIS)

    Kennedy, V.J.; Augusthy, A.; Varier, K.M.; Magudapathy, P.; Panchapakesan, S.; Nair, K.G.M.; Vijayan, V.

    1999-01-01

    The Chaliyar river, located in Kerala, India has shown preoccupying pollution levels, that constitute a threat to public health and the ecological system. PIXE and PIGE techniques have been employed to measure the elemental concentrations in the river sediment samples. Thick targets were prepared out of the sediment samples collected from various sites along the course of the river. The measurements were carried out using 3 MeV proton beam obtained from 3 MV Tandem pelletron accelerator at Institute of Physics, Bhubaneswar. The elemental concentrations, especially that of heavy metals, at different sites are discussed in detail. Our results show that sediments from a site where the industrial activities are high are significantly high in concentrations of heavy metals (Cr, Ni, Cu, Zn, Hg and Pb) than those collected from non-industrial sites. The measured values are compared with the average composition of unpolluted river sediments and other national and international river sediments. (author)

  13. Contaminated sediment transport during floods

    International Nuclear Information System (INIS)

    Fontaine, T.A.

    1992-01-01

    Over the past 48 years, operations and waste disposal activities at Oak Ridge National Laboratory have resulted in the contamination of parts of the White Oak Creek catchment. The contaminants presenting the highest risk to human health and the environment are particle reactive and are associated with the soils and sediments in the White Oak Creek drainage system. The erosion of these sediments during floods can result in the transport of contaminants both within the catchment and off-site into the Clinch River. A data collection program and a modeling investigation are being used to evaluate the probability of contaminated sediment transport during floods and to develop strategies for controlling off-site transport under present and future conditions

  14. The assessment of sediment screening risk in Venice Lagoon and other coastal areas using international sediment quality guidelines

    International Nuclear Information System (INIS)

    Apitz, S.A.; Barbanti, A.; Bocci, M.; Delaney, E.; Bernstein, A.G.; Montobbio, L.

    2007-01-01

    A number of studies carried out in recent years have shown the presence of a wide range of contaminants in the Venice Lagoon. It is important to have a good understanding of the ecological quality of Venice Lagoon sediments, in order to: i) define and locate areas where a threat to the environment is present and therefore an intervention is needed (i.e. in situ assessment and management); and ii) define sustainable and environmentally correct ways of managing sediments which are to be dredged for navigational purposes or in relation to other interventions (i.e., ex situ management). Materials and Methods: To examine how various regional and international SQGs 'classed' screening risk in Venice Lagoon sediments, data on median contaminant levels in surface sediments in Venice Lagoon resulting from a literature review were compared to a range of local and international sediment quality guidelines (SQGs). Then data on sediment contaminant levels in various areas and sub-basins of Venice Lagoon (main Lagoon, Porto Marghera and Venice City Canals) and in other regional and international transitional and coastal ecosystems with various levels of human impact (urbanization and industrialization) were evaluated based upon a selected consensus-based SQG. Finally, screening sediment quality for all of Venice Lagoon was mapped and contoured, relative to this consensus-based SQG and briefly compared with direct toxicity measurement through a battery of bioassays. Results: SQGs allow the sediment areas to be put in terms of potential, or screening, risk. Although there were some differences depending upon which specific SQGs were applied, the Venice SQGs and other international SQGs provided the same general picture of screening risk in Venice Lagoon despite geographic differences. Venice Lagoon South has the lowest screening risk levels, Venice Lagoon Central/North has the highest (and is nearest to the Porto Marghera and Venice City Canals sites). Discussion: The Venice

  15. Application of {sup 137}Cs and {sup 210}Pb radionuclides to determine sedimentation rates of recent sediments from Admiralty Bay, Antarctica Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Mylene Giseli do; Martins, Cesar de Castro [Universidade Federal do Parana (UFPR), Pontal do Parana, PR (Brazil). Centro de Estudos do Mar (CEM); Figueira, Rubens C.L.; Montone, Rosalinda C.; Mahiques, Michel M. de; Tessler, Moyses G., E-mail: rfigueira@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. Oceanografico. Dept. de Oceanografia Fisica, Quimica e Geologica; Vendrame, Antonio C. [Universidade Cruzeiro do Sul, Sao Paulo, SP (Brazil)

    2009-07-01

    Studies about natural and artificial radionuclides in areas such as the Antarctic are key to understand natural and dynamic processes in marine environments. These studies are important to determine levels of radioactive elements and local sedimentation rates. Five marine sediment cores were collected in different points of Admiralty Bay, in the Antarctic Peninsula. The purpose of this study was to determine {sup 137}Cs, {sup 226}Ra and {sup 210}Pb and sedimentation rates at each site. {sup 137}Cs, {sup 210}Pb and {sup 226}Ra were assayed by gamma-counting through direct measurement of the peak at 661 keV, 47 keV and 609 keV, respectively. Sedimentation rates were obtained by {sup 137}Cs and {sup 210}Pb (CIC and CRS). The activities for {sup 137}Cs ranged from 0.84 to 7.09 Bq kg{sup -1}; to {sup 226}Ra from 6.77 to 31.07 Bq kg{sup -1} for {sup 210}Pb ranged from 1.10 to 36.90 Bq kg{sup -1}. The sedimentation rates obtained by the three models ranged from 0.11+-0.01 cm y{sup -1} to 0.46+-0.05 cm y{sup -1}. The levels of {sup 137}Cs registered in this study, as well as in other studies in the Antarctic region indicate that global fallout is the main cause of artificial radionuclides present in this environment, since the Antarctic has not suffered a direct action of human activities that released radioactive elements. The possible grain size variations that occur in the studied points of Admiralty Bay may explain the differences found in the vertical distribution of radionuclides, because of the different values of sedimentation rates and respective dating determined in their profiles. (author)

  16. Suspended sediment and sediment-associated contaminants in San Francisco Bay

    Science.gov (United States)

    Schoellhamer, D.H.; Mumley, T.E.; Leatherbarrow, J.E.

    2007-01-01

    Water-quality managers desire information on the temporal and spatial variability of contaminant concentrations and the magnitudes of watershed and bed-sediment loads in San Francisco Bay. To help provide this information, the Regional Monitoring Program for Trace Substances in the San Francisco Estuary (RMP) takes advantage of the association of many contaminants with sediment particles by continuously measuring suspended-sediment concentration (SSC), which is an accurate, less costly, and more easily measured surrogate for several trace metals and organic contaminants. Continuous time series of SSC are collected at several sites in the Bay. Although semidiurnal and diurnal tidal fluctuations are present, most of the variability of SSC occurs at fortnightly, monthly, and semiannual tidal time scales. A seasonal cycle of sediment inflow, wind-wave resuspension, and winnowing of fine sediment also is observed. SSC and, thus, sediment-associated contaminants tend to be greater in shallower water, at the landward ends of the Bay, and in several localized estuarine turbidity maxima. Although understanding of sediment transport has improved in the first 10 years of the RMP, determining a simple mass budget of sediment or associated contaminants is confounded by uncertainties regarding sediment flux at boundaries, change in bed-sediment storage, and appropriate modeling techniques. Nevertheless, management of sediment-associated contaminants has improved greatly. Better understanding of sediment and sediment-associated contaminants in the Bay is of great interest to evaluate the value of control actions taken and the need for additional controls. ?? 2007 Elsevier Inc. All rights reserved.

  17. Velocity-porosity relationships for slope apron and accreted sediments in the Nankai Trough Seismogenic Zone Experiment, Integrated Ocean Drilling Program Expedition 315 Site C0001

    Science.gov (United States)

    Hashimoto, Y.; Tobin, H. J.; Knuth, M.

    2010-12-01

    In this study, we focused on the porosity and compressional wave velocity of marine sediments to examine the physical properties of the slope apron and the accreted sediments. This approach allows us to identify characteristic variations between sediments being deposited onto the active prism and those deposited on the oceanic plate and then carried into the prism during subduction. For this purpose we conducted ultrasonic compressional wave velocity measurements on the obtained core samples with pore pressure control. Site C0001 in the Nankai Trough Seismogenic Zone Experiment transect of the Integrated Ocean Drilling Program is located in the hanging wall of the midslope megasplay thrust fault in the Nankai subduction zone offshore of the Kii peninsula (SW Japan), penetrating an unconformity at ˜200 m depth between slope apron sediments and the underlying accreted sediments. We used samples from Site C0001. Compressional wave velocity from laboratory measurements ranges from ˜1.6 to ˜2.0 km/s at hydrostatic pore pressure conditions estimated from sample depth. The compressional wave velocity-porosity relationship for the slope apron sediments shows a slope almost parallel to the slope for global empirical relationships. In contrast, the velocity-porosity relationship for the accreted sediments shows a slightly steeper slope than that of the slope apron sediments at 0.55 of porosity. This higher slope in the velocity-porosity relationship is found to be characteristic of the accreted sediments. Textural analysis was also conducted to examine the relationship between microstructural texture and acoustic properties. Images from micro-X-ray CT indicated a homogeneous and well-sorted distribution of small pores both in shallow and in deeper sections. Other mechanisms such as lithology, clay fraction, and abnormal fluid pressure were found to be insufficient to explain the higher velocity for accreted sediments. The higher slope in velocity-porosity relationship for

  18. Metal assessment in sediments from the Guarapiranga Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Coutinho, Suellen N.; Figueiredo, Ana Maria G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Quináglia, Gilson A., E-mail: sncoutinho@usp.br, E-mail: anamaria@ipen.br, E-mail: gquinaglia@sp.gov.br [Companhia Ambiental do Estado de São Paulo (CETESB), São Paulo, SP (Brazil)

    2017-07-01

    The study of the distribution of metals in sediments is very important from the point of view of environmental pollution once the sediment concentrates metals in aquatic systems and represents a relevant contamination monitor. The analysis of sediments has been used to evaluate the quality of aquatic systems in relation to the concentration of metals. This study aimed to assess sediment contamination by metals in the Guarapiranga Reservoir. Sediment and water samples were analyzed by ICP OES (Inductively Coupled Plasma Optical Emission Spectrometry) for As, Cd, Cr, Cu, Ni, Pb and Zn and by CV AAS (Cold Vapor Atomic Absorption Spectrophotometry) for Hg. The sediment samples results were compared to TEL (Threshold Effect Level) and PEL (Probable Effect Level) guidance values and RRV (Reference Regional Values). Geoaccumulation Index (I{sub geo}) was calculated to evaluate metals pollution degree using reference values established for metals and metalloids in sediments from the Upper Tietê Basin and E{sub H}-pH diagrams were applied to explain chemical forms and bioavailability of toxic metals in sediment samples. In general, most of the analyzed elements exceeded TEL values and Cr, Cu and Zn exceeded RRV guidelines. The high concentrations of Cu found in this reservoir can be explained by the frequent application of CuSO{sub 4} algicide, mainly at sampling site S-03. The I{sub geo} indicated moderated polluted sediments by Zn and moderately to extremely polluted sediments by Cu, especially at S-03, in agreement with the TEL, PEL and RRV values comparison. These results may indicate potential risk of the reservoir water quality. (author)

  19. Roanoke 10 x 20 NTMS area, Virginia. Data report (abbreviated): National Uranium Resource Evaluation program, hydrogeochemical and stream sediment reconnaissance

    International Nuclear Information System (INIS)

    Cook, J.R.

    1980-12-01

    This abbreviated data report presents results of ground water and stream sediment reconnaissance in the National Topographic Map Series Roanoke 1 0 x 2 0 quadrangle. Surface sediment samples were collected at 1235 sites. Ground water samples were collected at 767 sites. Neutron activation analysis results are given for uranium and 16 other elements in sediments, and for uranium and 8 other elements in ground water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented. Data from ground water sites include (1) water chemistry measurements (pH, conductivity, and alkalinity), (2) physical measurements where applicable (water temperature, well description, etc.), and (3) elemental analyses (U, Al, Br, Cl, Dy, F, Mn, Na, and V). Data from sediment sites include (1) stream water chemistry measurements (pH, conductivity, and alkalinity), and (2) elemental analyses for sediment samples (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Sample site descriptors (stream characteristics, vegetation, etc.) are tabulated. Areal distribution maps, histograms, and cumulative frequency plots for most elements and for U/Th and U/Hf ratios are included. Key data from stream water sites include (1) water quality measurements (pH, conductivity, and alkalinity) and (2) elemental analyses (U, Al, Br, Cl, Dy, F, Mg, Mn, Na, and V). Uranium concentrations in the sediments range from 0.50 to 83.50 ppM with a mean of 6.67 ppM. A cluster of high log (U/Th + Hf) ratios appear in the southeastern portion of the quadrangle. Uranium, thorium, and the rare earth elements show a striking correlation with the geology of the area

  20. Tributyltin-resistant bacteria from estuarine and freshwater sediments.

    Science.gov (United States)

    Wuertz, S; Miller, C E; Pfister, R M; Cooney, J J

    1991-01-01

    Resistance to tributyltin (TBT) was examined in populations from TBT-polluted sediments and nonpolluted sediments from an estuary and from fresh water as well as in pure cultures isolated from those sediments. The 50% effective concentrations (EC50s) for populations were higher at a TBT-polluted freshwater site than at a site without TBT, suggesting that TBT selected for a TBT-resistant population. In contrast, EC50s were significantly lower for populations from a TBT-contaminated estuarine site than for those from a site without TBT, suggesting that other factors in addition to TBT determine whether populations become resistant. EC50s for populations from TBT-contaminated freshwater sediments were nearly 30 times higher than those for populations from TBT-contaminated estuarine sediments. We defined a TBT-resistant bacterium as one which grows on trypticase soy agar containing 8.4 microM TBT, a concentration which prevented the growth of 90% of the culturable bacteria from these sediments. The toxicity of TBT in laboratory media was influenced markedly by the composition of the medium and whether it was liquid or solid. Ten TBT-resistant isolates from estuarine sediments and 19 from freshwater sediments were identified to the genus level. Two isolates, each a Bacillus sp., may be the first gram-positive bacteria isolated from fresh water in the presence of a high concentration of TBT. There was a high incidence of resistance to heavy metals: metal resistance indices were 0.76 for estuarine isolates and 0.68 for freshwater isolates.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1746939

  1. Genesis and continuity of quaternary sand and gravel in glacigenic sediment at a proposed low-level radioactive waste disposal site in east-central Illinois

    Science.gov (United States)

    Troost, K.G.; Curry, B. Brandon

    1991-01-01

    The Illinois Department of Nuclear Safety has characterized the Martinsville Alternative Site (MAS) for a proposed low-level radioactive waste disposal facility. The MAS is located in east-central Illinois approximately 1.6 km (1 mi) north of the city of Martinsville. Geologic investigation of the 5.5-km2 (1380-acre) site revealed a sequence of chiefly Illinoian glacigenic sediments from 6 to 60 m (20-200 ft) thick overlying two major bedrock valleys carved in Pennsylvanian strata. Relatively permeable buried units include basal, preglacial alluvium; a complex of intraglacial and subglacial sediment; englacial deposits; and supraglacial fluvial deposits. Postglacial alluvium underlies stream valleys on and adjacent to the site. In most areas, the buried sand units are confined by low-permeability till, lacustrine sediment, colluvium, and loess. The distribution and thickness of the most extensive and continuous buried sand units have been modified considerably by subglacial erosion, and their distributions have been influenced by the buried bedrock valleys. The most continuous of the various sand units were deposited as preglacial and postglacial alluvium and are the uppermost and lowermost stratigraphic units at the alternative site. Sand units that were deposited in englacial or ice-marginal environments are less continuous. Aquifer pumping tests, potentiometric head data, and groundwater geochemistry analyses indicate minimal interaction of groundwater across localized interconnections of the permeable units. ?? 1991 Springer-Verlag New York Inc.

  2. Development of MCESC software for selecting the best stormwater erosion and sediment control measure in Malaysian construction sites

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hadu, Ibrahiem Abdul Razak; Sidek, Lariyah Mohd [Civil Engineering Universiti Tenaga Nasional, Kajan, Selangor (Malaysia); Desa, Mohamed Nor Mohamed; Basri, Noor Ezlin Ahmad [Civil and Structural Engineering, Universiti Kebangsaan Malaysia, Bangi, Selangor (Malaysia)

    2012-07-01

    Malaysia located in a tropical region which is interested with a heavy rainfall through the whole seasons of the year. Construction stages usually associated with soil disturbing due to land clearing and grading activities, this combined with the tropical climate in Malaysia, will generate an enormous amount of soil to be eroded and then deposited into the adjacent water bodies. There are many kinds of mitigation measures used so as to reduce the impact of erosion and sedimentation that are generated due to the stormwater in construction sites. This paper aims to develop and apply Multi Criteria Analysis (MCA) software called Multi Criteria Erosion and Sediment Control (MCESC) software in which it can be applied in selecting the best stormwater control measure by depending on specified criteria and criterion weight. Visual Basic 6 was adopted as a development tool. This software can help the engineers, contractors on site and decision makers to find the best stormwater control measure in any construction site in Malaysia. Users of the MCESC software are given the opportunity to select the best stormwater control measure via expert's judgments that are built in the system or via their own expertise. MCESC software has many benefits since the experts are not always available and the consultancy is a costly issue which add further financial allocations to the project.

  3. Surface complexation modeling of U(VI) adsorption by aquifer sediments from a former mill tailings site at Rifle, Colorado

    Science.gov (United States)

    Hyun, S.P.; Fox, P.M.; Davis, J.A.; Campbell, K.M.; Hayes, K.F.; Long, P.E.

    2009-01-01

    A study of U(VI) adsorption by aquifer sediment samples from a former uranium mill tailings site at Rifle, Colorado, was conducted under oxic conditions as a function of pH, U(VI), Ca, and dissolved carbonate concentration. Batch adsorption experiments were performed using tailings site at Naturita, Colorado, indicated that possible calcite nonequilibrium of dissolved calcium concentration should be evaluated. The modeling results also illustrate the importance of the range of data used in deriving the best fit model parameters. ?? 2009 American Chemical Society.

  4. Application of neural networks to waste site screening

    International Nuclear Information System (INIS)

    Dabiri, A.E.; Garrett, M.; Kraft, T.; Hilton, J.; VanHammersveld, M.

    1993-02-01

    Waste site screening requires knowledge of the actual concentrations of hazardous materials and rates of flow around and below the site with time. The present approach consists primarily of drilling boreholes near contaminated sites and chemically analyzing the extracted physical samples and processing the data. This is expensive and time consuming. The feasibility of using neural network techniques to reduce the cost of waste site screening was investigated. Two neural network techniques, gradient descent back propagation and fully recurrent back propagation were utilized. The networks were trained with data received from Westinghouse Hanford Corporation. The results indicate that the network trained with the fully recurrent technique shows satisfactory generalization capability. The predicted results are close to the results obtained from a mathematical flow prediction model. It is possible to develop a new tool to predict the waste plume, thus substantially reducing the number of the bore sites and samplings. There are a variety of applications for this technique in environmental site screening and remediation. One of the obvious applications would be for optimum well siting. A neural network trained from the existing sampling data could be utilized to decide where would be the best position for the next bore site. Other applications are discussed in the report

  5. Radionuclides in sediments from Port Phillip Bay, Australia

    International Nuclear Information System (INIS)

    Smith, J.D.; Tinker, R.A.; Towler, P.H.

    1998-01-01

    Full text: Sediment cores were collected from two sites in Port Phillip Bay, Australia, in 1994 and 1995. The concentration of 210 Pb and parameters including water content were measured. The sites chosen were near the centre of the bay where fine sediment accumulates, and towards the northern end of the bay closer to the mouth of the Yarra River. The mid-bay sediment had a high water content (about 1.8 g water per g dry sediment) and a supported 210 Pb activity of about 22 mBq per g of dry sediment. The sediments from further north in the bay were more consolidated, with a lower water content (about 0.6 g water per g dry sediment), and had a supported 210 Pb activity of about 6 mBq per g of dry sediment. Unsupported 210 Pb occurred to depths of about 10 cm in the mid-bay sediment and about 20 cm in sediment from further north in the bay. Models incorporating the water and 210 Pb contents of the sediments were used to calculate possible rates of sediment accumulation and mixing. The distribution of other radionuclides was used as an aid in understanding the sediment behaviour in Port Phillip Bay

  6. Spatial dynamics of overbank sedimentation in floodplain systems

    Science.gov (United States)

    Pierce, Aaron R.; King, S.L.

    2008-01-01

    Floodplains provide valuable social and ecological functions, and understanding the rates and patterns of overbank sedimentation is critical for river basin management and rehabilitation. Channelization of alluvial systems throughout the world has altered hydrological and sedimentation processes within floodplain ecosystems. In the loess belt region of the Lower Mississippi Alluvial Valley of the United States, channelization, the geology of the region, and past land-use practices have resulted in the formation of dozens of valley plugs in stream channels and the formation of shoals at the confluence of stream systems. Valley plugs completely block stream channels with sediment and debris and can result in greater deposition rates on floodplain surfaces. Presently, however, information is lacking on the rates and variability of overbank sedimentation associated with valley plugs and shoals. We quantified deposition rates and textures in floodplains along channelized streams that contained valley plugs and shoals, in addition to floodplains occurring along an unchannelized stream, to improve our understanding of overbank sedimentation associated with channelized streams. Feldspar clay marker horizons and marker poles were used to measure floodplain deposition from 2002 to 2005 and data were analyzed with geospatial statistics to determine the spatial dynamics of sedimentation within the floodplains. Mean sediment deposition rates ranged from 0.09 to 0.67??cm/y at unchannelized sites, 0.16 to 2.27??cm/y at shoal sites, and 3.44 to 6.20??cm/y at valley plug sites. Valley plug sites had greater rates of deposition, and the deposited sediments contained more coarse sand material than either shoal or unchannelized sites. A total of 59 of 183 valley plug study plots had mean deposition rates > 5??cm/y. The geospatial analyses showed that the spatial dynamics of sedimentation can be influenced by the formation of valley plugs and shoals on channelized streams; however

  7. Atrazine degradation by bioaugmented sediment from constructed wetlands.

    Science.gov (United States)

    Runes, H B; Jenkins, J J; Bottomley, P J

    2001-10-01

    The potential to establish pesticide biodegradation in constructed wetland sediment was investigated. Under microcosm conditions, bioaugmentation of sediment with small quantities of an atrazine spill-site soil (1:100 w/w) resulted in the mineralization of 25-30% of 14C ethyl atrazine (1-10 microg g(-1) sediment) as 14CO2 under both unsaturated and water-saturated conditions; atrazine and its common metabolites were almost undetectable after 30 days incubation. By comparison, unbioaugmented sediment supplemented with organic amendments (cellulose or cattail leaves) mineralized only 2-3% of 14C ethyl atrazine, and extractable atrazine and its common metabolites comprised approximately 70% of the original application. The population density of atrazine-degrading microorganisms in unbioaugmented sediment was increased from approximately 10(2)/g to 10(4)/g by bioaugmentation (1:100 w/w), and increased by another 60-fold (6.0x10(5) g(-1)) after incubation with 10 microg g(-1) of atrazine. A high population of atrazine degraders (approximately 10(6) g(-1)) and enhanced rates of atrazine mineralization also developed in bioaugmented sediment after incubation in flooded mesocosms planted with cattails (Typha latifolia) and supplemented with atrazine (3.2 mg l(-1), 1 microg g(-1) sediment). In the absence of atrazine, neither the population of atrazine degraders, nor the atrazine mineralizing potential of bioaugmented sediment increased, regardless of the presence or absence of cattails. Bioaugmentation might be a simple method to promote pesticide degradation in nursery run-off channeled through constructed wetlands, if persistence of degraders in the absence of pesticide is not a serious constraint.

  8. Backreef and beach carbonate sediments of the Red Sea, Saudi Arabia: impacts of reef geometry and currents on sediment composition

    KAUST Repository

    Missimer, T. M.

    2017-07-01

    Three sites in the Red Sea were investigated to assess the variability of composition in Holocene sediments of the backreef environment within 0–2 m of water depth. This is important because composition of the sediment is commonly used to estimate water depth in ancient carbonate rocks. The site located at the King Abdullah Economic City (Saudi Arabia) contains a fringing reef with the reef tract located very close to the beach at the north end, flaring to the south to produce a narrower backreef area compared to the other two sites. This geometry produces a north to south current with a velocity of up to 15 cm s−1, particularly during high onshore winds. The sediments contain predominantly non-skeletal grains, including peloids, coated grains, ooids, and grapestones that form on the bottom. The percentage of coralgal grains in the sediment was significantly lower than at the other two sites studied. Om Al Misk Island and Shoaiba have a much lower-velocity current within the backreef zone and contain predominantly coralgal sediments from the beach to the landward edge of the reef tract. The two locations containing the predominantly coralgal microfacies were statistically similar, but the King Abdullah Economic City site was statistically different despite having a similar water depth profile. Slight differences in reef configuration, including reef orientation and distance from the shore, can produce considerable differences in sediment thickness and composition within the backreef environment, which should induce caution in the interpretation of water depth in ancient carbonate rocks using composition.

  9. Backreef and beach carbonate sediments of the Red Sea, Saudi Arabia: impacts of reef geometry and currents on sediment composition

    Science.gov (United States)

    Missimer, T. M.; Al-Mashharawi, S.; Dehwah, A. H. A.; Coulibaly, K.

    2017-12-01

    Three sites in the Red Sea were investigated to assess the variability of composition in Holocene sediments of the backreef environment within 0-2 m of water depth. This is important because composition of the sediment is commonly used to estimate water depth in ancient carbonate rocks. The site located at the King Abdullah Economic City (Saudi Arabia) contains a fringing reef with the reef tract located very close to the beach at the north end, flaring to the south to produce a narrower backreef area compared to the other two sites. This geometry produces a north to south current with a velocity of up to 15 cm s-1, particularly during high onshore winds. The sediments contain predominantly non-skeletal grains, including peloids, coated grains, ooids, and grapestones that form on the bottom. The percentage of coralgal grains in the sediment was significantly lower than at the other two sites studied. Om Al Misk Island and Shoaiba have a much lower-velocity current within the backreef zone and contain predominantly coralgal sediments from the beach to the landward edge of the reef tract. The two locations containing the predominantly coralgal microfacies were statistically similar, but the King Abdullah Economic City site was statistically different despite having a similar water depth profile. Slight differences in reef configuration, including reef orientation and distance from the shore, can produce considerable differences in sediment thickness and composition within the backreef environment, which should induce caution in the interpretation of water depth in ancient carbonate rocks using composition.

  10. Water-rock interactions in volcaniclastic sediments across the Izu-Bonin-Mariana Arc: comparison of sites U1438, U1201, 792 and 793.

    Science.gov (United States)

    van der Land, C.; Sena, C.; Loudin, L. C.; Zhang, Z.

    2014-12-01

    The rapid deposition of volcanogenic sediments, highly susceptible to alteration by seawater has led to distinct pore water geochemical profiles throughout the sedimentary basins of the Izu-Bonin-Mariana Arc. Drilling at Site U1438, in the Amami-Sankaku Basin, recovered a 1300 m thick volcaniclastic section overlain by a 160 m thick section of sediments largely devoid of volcanic input. At Site U1438, 67 porewater samples were analyzed onboard for salinity, pH, oxidation-reduction potential and major and trace element concentrations. Here we focus on the depth profiles of elements which were also analyzed at Sites U1201, 792 and 793. Chloride and Bromide concentrations display similar trends; near constant in the upper 160 m and a linear downward increase to maximum concentrations from 600 mbsf onwards. This increase is likely caused by uptake of water by secondary minerals, resulting in chloride and bromide enrichment in the porewater. Calcium and magnesium porewater concentrations display opposite trends in the upper 440 m; the first increases from 11.5 to 140 mM, and the latter decreases from 53 mM until its depletion in the porewater. Leaching of Ca from the glass-rich sediments and underlying igneous basement are potential sources for Ca in the porewater, while Mg, Na and K presumably replace Ca through cation-exchange. Compared to Site U1438, similar trends of major elements concentration in the pore water were observed at the nearby Sites U1201 (serpentine mud volcano in the forearc of the Mariana subduction system), 792 and 793 (both in the Izu-Bonin forearc sedimentary basin). However, differences in depositional rates, thickness and age of the sedimentary basins, geothermal gradients and the influence of serpentine mud flows, have led to distinct pore water geochemical profiles.

  11. Elemental concentration variations in Plio-Pleistocene sediments from ODP Site 1143 (southern South China Sea) obtained by XRF analyses

    Science.gov (United States)

    Tian, J.; Xie, X.; Jin, H.; Wang, P.; Jian, Z.

    2009-12-01

    Energy dispersive X-ray fluorescence (XRF) scanning technology provides the most accurate and most economic analytical methods for the determination of major and minor elements of the deep-sea sediment ranging from sodium (11) to uranium (92). Scanning on the smooth core surface by XRF Core scanner is reliable and non-destructive to the sediment, requiring little or no time to prepare the core. This method overcomes the drawback of the traditional analytical method by ICP-AES or ICP-MS which requires long time for sample preparation. Thus, it makes it viable to reconstruct long and high-resolution elemental time series from sediment cores. We have performed relatively elemental concentration analyses on the deep sea sediment cores from ODP site 1143 (southern SCS) down to 190.77 mcd (meters composite depth) by XRF core scanner. The depth resolution of the scanning is 1 cm, equivalent to a time resolution of ~250 years. The age model is based on tuning the benthic foraminiferal d18O at Site 1143 to obliquity and precession (Tian et al., 2002) which indicates that the 190.77 meters long sediment spans the past 5 Myr. We compared the records between 99.5 and 136.46 mcd with the elemental records from the same site obtained by Philips PW 2400 X-ray spectrometer (Wehausen et al., online publication). Comparison reveals, regardless of the absolute changes of the elements, that the elemental records (Si, Ti, Al, Fe, Mn, Ca, K, P, Ba, Rb, Sr) obtained by two methods are nearly the same. Results show that the relative concentration variations of the productivity related elements such as Ba and Ca display distinctive glacial-interglacial cycles for the past 5 Myr. These productivity cycles recorded show one-on-one relationship with the glacial-interglacial cycles of the global ice volume change recorded in the benthic foraminiferal d18O. The glacial-interglacial cycles in productivity and global ice volume changes are consistent with each other not only in amplitude but also

  12. Calibration and application of the branched GDGT proxy on East African lake sediments

    NARCIS (Netherlands)

    Loomis, S.E.; Russell, J.M.; Ladd, B.; Street-Perrott, F.A.; Sinninghe Damsté, J.S.

    2012-01-01

    Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are a novel proxy for mean annual air temperature (MAAT) and have the potential to be broadly applicable to climate reconstruction using lacustrine sediments. Several calibrations have been put forth relating brGDGT distributions to MAAT using

  13. Journal of Computer Science and Its Application: Site Map

    African Journals Online (AJOL)

    Journal of Computer Science and Its Application: Site Map. Journal Home > About the Journal > Journal of Computer Science and Its Application: Site Map. Log in or Register to get access to full text downloads.

  14. Toxic evaluations of sediments in Tokyo Bay, Japan, using Japanese medaka embryos.

    Science.gov (United States)

    Uno, Seiichi; Kokushi, Emiko; Kawano, Machi; McElroy, Anne E; Koyama, Jiro

    2017-12-01

    Toxic risks of sediments collected from seven sites in Tokyo Bay were evaluated using Japanese medaka embryos. Those sediments with slight pore water were placed in grass petri dishes without overlying water. The most remarkable effect in the field sediment was to cause hatching delay in embryos, and the longest time until hatching took was 12.5 ± 1.6 days post-fertilization (dpf), although that in control group was 10.1 ± 0.7 dpf. A significant delay in hatching was observed at four sites. Because total carbon concentrations were relatively high in sediments at three of these four sites, several chemicals were expected to be residues in these sites and could cause their delay. Although extreme mortality was not observed at all sites, sediments collected from the site close to Kawasaki city induced 10 % mortality. Polycyclic aromatic hydrocarbon (PAH) concentrations were remarkably high at this site compared with other sites, and thus PAH toxicities could be causing the mortality. Concentration of heavy metals such as cadmium, copper, lead, and zinc in sediments were also determined, but no clear relationship was found between toxicities to embryos and the distribution of their concentrations.

  15. Surface sediment quality relative to port activities: A contaminant-spectrum assessment.

    Science.gov (United States)

    Yu, Shen; Hong, Bing; Ma, Jun; Chen, Yongshan; Xi, Xiuping; Gao, Jingbo; Hu, Xiuqin; Xu, Xiangrong; Sun, Yuxin

    2017-10-15

    Ports are facing increasing environmental concerns with their importance to the global economy. Numerous studies indicated sediment quality deterioration in ports; however, the deterioration is not discriminated for each port activity. This study investigated a spectrum of contaminants (metals and organic pollutants) in surface sediments at 20 sampling points in Port Ningbo, China, one of the top five world ports by volume. The spectrum of contaminants (metals and organic pollutants) was quantified following marine sediment quality guidelines of China and USA and surface sediment quality was assessed according to thresholds of the two guidelines. Coupling a categorical matrix of port activities with the matrix of sedimentary contaminants revealed that contaminants were highly associated with the port operations. Ship repair posed a severe chemical risk to sediment. Operations of crude oil and coal loadings were two top activities related to organic pollutants in sediments while port operations of ore and container loadings discharged metals. Among the 20 sampling points, Cu, Zn, Pb, and DDT and its metabolites were the priority contaminants influencing sediment quality. Overall, surface sediments in Port Ningbo had relatively low environmental risks but ship repair is an environmental concern that must be addressed. This study provides a practical approach for port activity-related quality assessment of surface sediments in ports that could be applicable in many world sites. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Alternation of Sediment Characteristics during Sediment Microbial Fuel Cells Amended Biochar

    Science.gov (United States)

    Yang, Xunan; Chen, Shanshan

    2018-01-01

    Sediment microbial fuel cells (SMFCs) are considered as a new technology in sediment remediation, while biochars can promote interspecies electron transfer in bioelectrochemical systems. We conducted the SMFCs amended with biochars to investigate their effects on of sediment characteristics. Results showed that the anode of SMFCs could oxidize the chemical oxidizable matter in sediments (by 4%-16%) correlating with the maximum power density (r=0.982, palternations under SMFC operation, which gave information on the element pool related to pollutants and the risk of the application of SMFCs.

  17. Erosion and Sediment Transport Modelling in Shallow Waters: A Review on Approaches, Models and Applications

    Directory of Open Access Journals (Sweden)

    Mohammad Hajigholizadeh

    2018-03-01

    Full Text Available The erosion and sediment transport processes in shallow waters, which are discussed in this paper, begin when water droplets hit the soil surface. The transport mechanism caused by the consequent rainfall-runoff process determines the amount of generated sediment that can be transferred downslope. Many significant studies and models are performed to investigate these processes, which differ in terms of their effecting factors, approaches, inputs and outputs, model structure and the manner that these processes represent. This paper attempts to review the related literature concerning sediment transport modelling in shallow waters. A classification based on the representational processes of the soil erosion and sediment transport models (empirical, conceptual, physical and hybrid is adopted, and the commonly-used models and their characteristics are listed. This review is expected to be of interest to researchers and soil and water conservation managers who are working on erosion and sediment transport phenomena in shallow waters. The paper format should be helpful for practitioners to identify and generally characterize the types of available models, their strengths and their basic scope of applicability.

  18. Erosion and Sediment Transport Modelling in Shallow Waters: A Review on Approaches, Models and Applications.

    Science.gov (United States)

    Hajigholizadeh, Mohammad; Melesse, Assefa M; Fuentes, Hector R

    2018-03-14

    The erosion and sediment transport processes in shallow waters, which are discussed in this paper, begin when water droplets hit the soil surface. The transport mechanism caused by the consequent rainfall-runoff process determines the amount of generated sediment that can be transferred downslope. Many significant studies and models are performed to investigate these processes, which differ in terms of their effecting factors, approaches, inputs and outputs, model structure and the manner that these processes represent. This paper attempts to review the related literature concerning sediment transport modelling in shallow waters. A classification based on the representational processes of the soil erosion and sediment transport models (empirical, conceptual, physical and hybrid) is adopted, and the commonly-used models and their characteristics are listed. This review is expected to be of interest to researchers and soil and water conservation managers who are working on erosion and sediment transport phenomena in shallow waters. The paper format should be helpful for practitioners to identify and generally characterize the types of available models, their strengths and their basic scope of applicability.

  19. Tributyltin-resistant bacteria from estuarine and freshwater sediments.

    OpenAIRE

    Wuertz, S; Miller, C E; Pfister, R M; Cooney, J J

    1991-01-01

    Resistance to tributyltin (TBT) was examined in populations from TBT-polluted sediments and nonpolluted sediments from an estuary and from fresh water as well as in pure cultures isolated from those sediments. The 50% effective concentrations (EC50s) for populations were higher at a TBT-polluted freshwater site than at a site without TBT, suggesting that TBT selected for a TBT-resistant population. In contrast, EC50s were significantly lower for populations from a TBT-contaminated estuarine s...

  20. Geophysical bed sediment characterization of the Androscoggin River from the former Chlor-Alkali Facility Superfund Site, Berlin, New Hampshire, to the state border with Maine, August 2009

    Science.gov (United States)

    Degnan, James R.; Teeple, Andrew; Johnston, Craig M.; Marvin-DiPasquale, Mark C.; Luce, Darryl

    2011-01-01

    The former Chlor-Alkali Facility in Berlin, New Hampshire, was listed on the U.S. Environmental Protection Agency National Priorities List in 2005 as a Superfund site. The Chlor-Alkali Facility lies on the east bank of the Androscoggin River. Elemental mercury currently discharges from that bank into the Androscoggin River. The nature, extent, and the speciation of mercury and the production of methyl mercury contamination in the adjacent Androscoggin River is the subject of continuing investigations. The U.S. Geological Survey, in cooperation with Region I of the U.S. Environmental Protection Agency, used geophysical methods to determine the distribution, thickness, and physical properties of sediments in the Androscoggin River channel at a small area of an upstream reference reach and downstream from the site to the New Hampshire–Maine State border. Separate reaches of the Androscoggin River in the study area were surveyed with surface geophysical methods including ground-penetrating radar and step-frequency electromagnetics. Results were processed to assess sediment characteristics including grain size, electrical conductivity, and pore-water specific conductance. Specific conductance measured during surface- and pore-water sampling was used to help interpret the results of the geophysical surveys. The electrical resistivity of sediment samples was measured in the laboratory with intact pore water for comparison with survey results. In some instances, anthropogenic features and land uses, such as roads and power lines affected the detection of riverbed properties using geophysical methods; when this occurred, the data were removed. Through combining results, detailed riverbed sediment characterizations were made. Results from ground-penetrating radar surveys were used to image and measure the depth to the riverbed, depth to buried riverbeds, riverbed thickness and to interpret material-type variations in terms of relative grain size. Fifty two percent of the

  1. Spatial glyphosate and AMPA redistribution on the soil surface driven by sediment transport processes - A flume experiment.

    Science.gov (United States)

    Bento, Célia P M; Commelin, Meindert C; Baartman, Jantiene E M; Yang, Xiaomei; Peters, Piet; Mol, Hans G J; Ritsema, Coen J; Geissen, Violette

    2018-03-01

    This study investigates the influence of small-scale sediment transport on glyphosate and AMPA redistribution on the soil surface and on their off-site transport during water erosion events. Both a smooth surface (T1) and a surface with "seeding lines on the contour" (T2) were tested in a rainfall simulation experiment using soil flumes (1 × 0.5 m) with a 5% slope. A dose of 178 mg m -2 of a glyphosate-based formulation (CLINIC ® ) was applied on the upper 0.2 m of the flumes. Four 15-min rainfall events (RE) with 30-min interval in between and a total rainfall intensity of 30 mm h -1 were applied. Runoff samples were collected after each RE in a collector at the flume outlet. At the end of the four REs, soil and sediment samples were collected in the application area and in four 20 cm-segments downslope of the application area. Samples were collected according to the following visually distinguished soil surface groups: light sedimentation (LS), dark sedimentation (DS), background and aggregates. Results showed that runoff, suspended sediment and associated glyphosate and AMPA off-site transport were significantly lower in T2 than in T1. Glyphosate and AMPA off-site deposition was higher for T2 than for T1, and their contents on the soil surface decreased with increasing distance from the application area for all soil surface groups and in both treatments. The LS and DS groups presented the highest glyphosate and AMPA contents, but the background group contributed the most to the downslope off-site deposition. Glyphosate and AMPA off-target particle-bound transport was 9.4% (T1) and 17.8% (T2) of the applied amount, while water-dissolved transport was 2.8% (T1) and 0.5% (T2). Particle size and organic matter influenced the mobility of glyphosate and AMPA to off-target areas. These results indicate that the pollution risk of terrestrial and aquatic environments through runoff and deposition can be considerable. Copyright © 2017 Elsevier Ltd

  2. Post depositional memory record of mercury in sediment near effluent disposal site of a chlor-alkali plant in Thane Creek-Mumbai Harbour, India

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.; Rokade, M.A.; Zingde, M.D.; Borole, D.V.

    in landfills, mine tailings, contaminated industrial sites, soils and sediments. Estuaries and coastal marine regions form an essential link in the global biogeochemical cycling of Hg between the terrestrial environment - the major repository for atmospheric... by close relationship with organic matter, and Fe and Al oxides or sorbed onto the mineral particles [8]. Hence, sediments adjacent to the outfalls of chlor-alkali plants frequently contain high levels of Hg [7,10-15]. Some natural processes (water, soil...

  3. Algal stabilisation of estuarine sediments

    International Nuclear Information System (INIS)

    1992-01-01

    The presence of benthic microalgae can increase the stability of intertidal sediments and influence sediment fluxes within an estuarine environment. Therefore the relative importance of algal stabilisation needs to be understood to help predict the effects of a tidal barrage. The biogenic stabilisation of intertidal estuarine sediments by epipelic diatom films and the macrophyte Vaucheria was studied at three sites on the Severn Estuary. The cohesive strength meter (CSM) was developed to measure surface critical shear stress with varied algal density. A number of techniques have been used to determine the general in situ erodibility of cohesive estuarine sediments. The measurements of sediment shear strength and critical erosion velocity were investigated. Field experiments were undertaken to investigate the effect of algae on binding sediments, and a predictive method for the assessment of sediment stabilisation by algal binding was developed. (author)

  4. Authigenic Uranium in Eastern Equatorial Pacific Sediments

    Science.gov (United States)

    Marcantonio, F.; Lyle, M. W.; Loveley, M. R.; Ibrahim, R.

    2014-12-01

    Authigenic U concentrations have been used as an indicator of redox state in marine sediments. Soluble U(VI) in porewaters is reduced to insoluble U(IV) under suboxic conditions setting up a diffusion gradient through which U in bottom waters is supplied to reducing sediments. Researchers have used sedimentary redox enrichment of U as a tool to identify past redox changes, which may be caused by changes in organic carbon rain rates and/or bottom water oxygen levels. Differentiating between these two explanations is important, as the former is tied to the use of authigenic U as a paleoproductivity proxy. We examined sediments from 4 sediment cores retrieved from two different localities in the Panama Basin in the eastern equatorial Pacific. Two cores were retrieved from the northern Panama basin at the Cocos Ridge, (4JC at 5° 44.7'N 85° 45.5' W, 1730 m depth; 8JC at 6° 14.0'N 86° 2.6' W, 1993 m depth), and two were retrieved from the south at the Carnegie Ridge, (11JC at 0° 41.6'S 85° 20.0' W, 2452 m depth; 17JC at 0° 10.8'S 85° 52.0' W, 2846 m depth). Using 230Th systematics and seismic profiling at each of the sites, we've identified significant sediment winnowing (4JC and 11JC) and focusing (8JC and 17JC). At all sites, we believe that changes in age-model-derived sand (i.e., >63µm) mass accumulation rates (MAR) best represent changes in rain rates. Glacial rain rates are higher than those in the Holocene by a factor of 2-3 at both sites. Peak Mn levels (>1%), the brown-to-green color transition (which likely represents the oxic/post-oxic boundary), and peak U concentrations all appear in the same order with increasing depth down core. At the Carnegie sites, where MARs are greater than those at the Cocos sites, increases in authigenic U (up to 4 ppm) occur during the mid- to late Holocene at depths of 10-15 cm. At the Cocos sites, increases in authigenic U (up to 12 ppm) occur lower in the sediment column (25-30 cm) during the late glacial. The decrease

  5. Application of numerical simulation on optimum design of two-dimensional sedimentation tanks in the wastewater treatment plant.

    Science.gov (United States)

    Zeng, Guang-Ming; Zhang, Shuo-Fu; Qin, Xiao-Sheng; Huang, Guo-He; Li, Jian-Bing

    2003-05-01

    The paper establishes the relationship between the settling efficiency and the sizes of the sedimentation tank through the process of numerical simulation, which is taken as one of the constraints to set up a simple optimum designing model of sedimentation tank. The feasibility and advantages of this model based on numerical calculation are verified through the application of practical case.

  6. Integrated stratigraphy and 40Ar/39Ar chronology of early Middle Miocene sediments from DSDP Leg 42A, Site 372 (Western Mediterranean)

    NARCIS (Netherlands)

    Abdul Aziz, H.; di Stefano, A.; Foresi, L. M.; Hilgen, Frederik J.; Iaccarino, S. M.; Kuiper, K. F.; Lirer, F.; Salvatorini, G.; Turco, E.

    2008-01-01

    An integrated magneto-biostratigraphic framework is presented for Middle Miocene sediments of DSDP Site 372 located in the Western Mediterranean. Detailed biostratigraphic analysis shows a nearly complete sequence of early Middle Miocene calcareous plankton bioevents in the Mediterranean, including

  7. Hourly and daily variation of sediment redox potential in tidal wetland sediments

    Science.gov (United States)

    Catallo, W. James

    1999-01-01

    Variation of electrochemical oxidation-reduction (redox) potential was examined in surface salt march sediments under conditions of flooding and tidal simulation in mesocosms and field sites. Time series were generated of redox potential measured in sediment profiles at 2-10 cm depth using combination Pt-Ag/AgCl (ORP) electrodes. Redox potential data were acquired at rapid rates (1-55 samples/h) over extended periods (3-104 days) along with similar times series of temperature (water, air, soil) and pH. It was found that redox potential vaired as a result of water level changes and was unrelated to diurnal changes in temperature or pH, the latter of which changed by 370 mV redox potential decrease in under 48 hours). Attenuatoin of microbial activity by [gamma] y-radiation and toxic chemicals elimintated this response. In tidal salt marsh mesocosms where the sediment-plant assemblages were exposed to a simulated diurnal tide, redox potenial oscillations of 40-300 mV amplitude were recoded that has the same periodicity as the flood-drain cycle. Periodic redoc potential time series were observed repeatedly in sediments receiving tidal pulsing but not in those sediments exposed to static hydrological conditions. Data collected over 12 days from a coastal marsh site experiencing diurnal tides showed similar fluctuations in redox potential. Data from the experimentents indicated that (a) redox potential can be a dynamic, nonlinear variable in coastal and estuarine wetland sediments over hourly and daily scales, and the designs of biogeochemical experiments should reflect this, (b) redox potential can change rapidly and signigicantly in coastal wetland sediments in response of flooding and draining, (c) microbial community processes are primarily determinants of the time course of redox potential in wetland sediments, and elimination of inhibition of microbial activity (e.g. by pollutants) can significantly alter that behavior, and (d) fast redox potential dynamics appear

  8. Boston 10 x 20 NTMS area, Massachusetts, and New Hampshire. Data report (abbreviated): National Uranium Resource Evaluation program, hydrogeochemical and stream sediment reconnaissance

    International Nuclear Information System (INIS)

    Cook, J.R.

    1980-01-01

    Results of ground water and stream sediment reconnaissance in the National Topographic Map Series (NTMS) Boston 1 0 x 2 0 quadrangle are presented. Surface sediment samples were collected at 669 sites. Ground water samples were collected at 303 sites. Neutron activation analysis (NAA) results are given for uranium and 16 other elements in sediments, and for uranium and 8 other elements in ground water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented. Data from ground water sites include (1) water chemistry measurements (pH, conductivity, and alkalinity), (2) physical measurements where applicable (water temperature, well description, etc.), and (3) elemental analyses (U, Al, Br, Cl, Dy, F, Mn, Na, and V). Data from sediment sites include (1) stream water chemistry measurements (pH, conductivity, and alkalinity), and (2) elemental analyses for sediment samples (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Sample site descriptors (stream characteristics, vegetation, etc.) are also tabulated. Areal distribution maps, histograms, and cumulative frequency plots for most elements and for U/Th and U/Hf ratios are included on the microfiche. Key data from stream water sites include (1) water quality measurements (pH, conductivity, and alkalinity) and (2) elemental analyses (U, Al, Br, Ci, Dy, F, Mg, Mn, Na, and V). The maximum uranium concentration in the sediments of the Boston quadrangle was 82.1 ppM. The mean of the logarithms of the uranium concentrations in sediments was 0.68, which corresponds to 4.8 ppM uranium. A cluster of samples with uranium values greater than 40 ppM and which have low thorium concentrations occurs in Essex County, Massachusetts

  9. Methods for assessing mine site rehabilitation design for erosion impact

    International Nuclear Information System (INIS)

    Evans, K. G.

    2000-01-01

    Erosion of rehabilitated mines may result in landform instability, which in turn may result in exposure of encapsulated contaminants, elevated sediment delivery at catchment outlets, and subsequent degradation of downstream water quality. Rehabilitation design can be assessed using erosion and hydrology models calibrated to mine site conditions. Incision rates in containment structures can be quantified using 3-dimensional landform evolution simulation techniques. Sediment delivery at catchment outlets for various landform amelioration techniques can be predicted using process-based and empirical erosion-prediction models and sediment delivery ratios. The predicted sediment delivery can be used to estimate an average annual stream sediment load that can, in turn, be used to assess water quality impacts. Application of these techniques is demonstrated through a case study applied to a proposed rehabilitation design option for the Energy Resources of Australia Ltd (ERA) Ranger Mine in the Northern Territory of Australia. Copyright (2000) CSIRO Australia

  10. Geotechnical Survey, Dredgeability Of Soil Sediments And Siltation ...

    African Journals Online (AJOL)

    Geotechnical Survey, Dredgeability Of Soil Sediments And Siltation Volume Of Brimsu Water Reservoir. ... of the sediments was characterized by geo-technical descriptor terms, indicating that the sediments could be dredged using cutter-type dredger for excava-tion, and transported by hydraulic pipelines to disposal sites.

  11. Controls on sediment production in two U.S. deserts

    Science.gov (United States)

    Belnap, Jayne; Walker, Beau J.; Munson, Seth M.; Gill, Richard A.

    2014-01-01

    Much of the world’s airborne sediment originates from dryland regions. Soil surface disturbances in these regions are ever-increasing due to human activities such as energy and mineral exploration and development, recreation, suburbanization, livestock grazing and cropping. Sediment production can have significant impacts to human health with particles potentially carrying viruses such as Valley Fever or causing asthma or other respiratory diseases. Dust storms can cause decreased visibility at the ground level, resulting in highway accidents, and reduced visual quality in park and wildland airsheds. Sediment production and deposition is also detrimental to ecosystem health, as production reduces soil fertility at its source and can bury plants and other organisms where it is deposited. Therefore, it is important to understand how we can predict what areas are prone to producing sediment emissions both before and after soil surface disturbance. We visited 87 sites in two deserts of the western U.S. that represented a range of soil texture and surface cover types. We used a portable wind tunnel to estimate the threshold friction velocity (TFV) required to initiate sediment transport and the amount of sediment produced by the tunnel at a set wind speed. Wind tunnel runs were done before and after soil surface disturbance with a four-wheel drive vehicle. Results show that most undisturbed desert soils are very stable, especially if covered by rocks or well-developed biological soil crusts, which make them virtually wind-erosion proof. Particles at disturbed sites, in contrast, moved at relatively low wind speeds and produced high amounts of sediment. Silt was an important predictor of TFV and sediment production across all sites, whereas the influence of rock cover and biological soil crusts was site-dependent. Understanding the vulnerability of a site after disturbance is important information for land managers as they plan land use activities and attempt to

  12. Controls on sediment production in two U.S. deserts

    Science.gov (United States)

    Belnap, Jayne; Walker, Beau J.; Munson, Seth M.; Gill, Richard A.

    2014-09-01

    Much of the world’s airborne sediment originates from dryland regions. Soil surface disturbances in these regions are ever-increasing due to human activities such as energy and mineral exploration and development, recreation, suburbanization, livestock grazing and cropping. Sediment production can have significant impacts to human health with particles potentially carrying viruses such as Valley Fever or causing asthma or other respiratory diseases. Dust storms can cause decreased visibility at the ground level, resulting in highway accidents, and reduced visual quality in park and wildland airsheds. Sediment production and deposition is also detrimental to ecosystem health, as production reduces soil fertility at its source and can bury plants and other organisms where it is deposited. Therefore, it is important to understand how we can predict what areas are prone to producing sediment emissions both before and after soil surface disturbance. We visited 87 sites in two deserts of the western U.S. that represented a range of soil texture and surface cover types. We used a portable wind tunnel to estimate the threshold friction velocity (TFV) required to initiate sediment transport and the amount of sediment produced by the tunnel at a set wind speed. Wind tunnel runs were done before and after soil surface disturbance with a four-wheel drive vehicle. Results show that most undisturbed desert soils are very stable, especially if covered by rocks or well-developed biological soil crusts, which make them virtually wind-erosion proof. Particles at disturbed sites, in contrast, moved at relatively low wind speeds and produced high amounts of sediment. Silt was an important predictor of TFV and sediment production across all sites, whereas the influence of rock cover and biological soil crusts was site-dependent. Understanding the vulnerability of a site after disturbance is important information for land managers as they plan land use activities and attempt to

  13. An application of sedimentation simulation in Tahe oilfield

    Science.gov (United States)

    Tingting, He; Lei, Zhao; Xin, Tan; Dongxu, He

    2017-12-01

    The braided river delta develops in Triassic low oil formation in the block 9 of Tahe oilfield, but its sedimentation evolution process is unclear. By using sedimentation simulation technology, sedimentation process and distribution of braided river delta are studied based on the geological parameters including sequence stratigraphic division, initial sedimentation environment, relative lake level change and accommodation change, source supply and sedimentary transport pattern. The simulation result shows that the error rate between strata thickness of simulation and actual strata thickness is small, and the single well analysis result of simulation is highly consistent with the actual analysis, which can prove that the model is reliable. The study area belongs to braided river delta retrogradation evolution process, which provides favorable basis for fine reservoir description and prediction.

  14. THE EFFECT OF ORGANIC SEDIMENT CONTENT ON CORAL DIVERSITY IN KARIMUNJAWA ISLAND, INDONESIA

    Directory of Open Access Journals (Sweden)

    Fajar Nugroho

    2018-06-01

    Full Text Available Coral reef now are under threats due to sedimentation. Fatal effect of organic rich sediment, leading corals mortality. Therefore, the study was conducted to investigate effect of organic sediment content to the coral diversity in Karimunjawa Island, Central Java, Indonesia. Field data was conducted at 6 locations.  Three sediment traps were deployed at each sites to measure organic sediment content. Twenty replicated quadrant transects were used to estimate coral density and coral diversity. Analysis of variance (ANOVA was used to examine the differences of organic sediment content in each station. The linear regression was used to assess the relationship between organic sediment content and coral diversity. Our field result demonstrated that sediment content significantly different between sites with value range from 0.42 mg/800 ml - 1.32 mg/800 ml. Based on the Simson’s Diversity Index, the highest coral diversity found at Alang-alang as site with low sedimentation while the lowest coral diversity was found at Legon Lele as site with high sedimentation. The study shown significant negative correlation between organic sediment content and coral diversity with the coefficient of regression 0.68. This study convinces that disturbance on coral reefs might affect coral diversity in Karimunjawa Island, in addition to other factors such as the influence of human activities, natural disruption and climate change. Keywords: sedimentation, organic, coral, diversity, Karimunjawa

  15. Relationship of subseafloor microbial diversity to sediment age and organic carbon content

    Science.gov (United States)

    Walsh, E. A.; Kirkpatrick, J. B.; Sogin, M. L.; D'Hondt, S. L.

    2013-12-01

    Our tag pyrosequencing investigation of four globally distant sites reveals sediment age and total organic carbon content to be significant components in understanding subseafloor diversity. Our sampling locations include two sites from high-productivity regions (Indian Ocean and Bering Sea) and two from moderate-productivity (eastern and central equatorial Pacific Ocean). Sediment from the high-productivity sites has much higher TOC than sediment from the moderate-productivity equatorial sites. We applied a high-resolution 16S V4-V6 tag pyrosequencing approach to 24 bacterial and 17 archaeal samples, totaling 602,502 reads. We identified1,291 archaeal and 15,910 bacterial OTUs (97%) from these reads. We analyzed bacterial samples from all four sites in addition to archaeal samples from our high productivity sites. These high productivity, high TOC sites have a pronounced methane-rich sulfate-free zone at depth from which archaea have been previously considered to dominate (Biddle et al., 2006). At all four locations, microbial diversity is highest near the seafloor and drops rapidly to low but stable values with increasing sediment depth. The depth at which diversity stabilizes varies greatly from site to site, but the age at which it stabilizes is relatively constant. At all four sites, diversity reaches low stable values a few hundred thousand years after sediment deposition. The sites with high total organic carbon (high productivity sites) generally exhibit higher diversity at each sediment age than the sites with lower total organic carbon (moderate-productivity sites). Archaeal diversity is lower than bacterial diversity at every sampled depth. Biddle, J.F., Lipp, J.S., Lever, M.A., Lloyd, K.G., Sørensen, K.B., Anderson, R. et al. (2006) Heterotrophic Archaea dominate sedimentary subsurface ecosystems off Peru. PNAS 103: 3846-3851.

  16. Resuspension of polychlorinated biphenyl-contaminated field sediment: release to the water column and determination of site-specific K DOC.

    Science.gov (United States)

    Friedman, Carey L; Lohmann, Rainer; Burgess, Robert M; Perron, Monique M; Cantwell, Mark G

    2011-02-01

    Sediments from the New Bedford Harbor (NBH) U.S. Environmental Protection Agency (U.S. EPA) Superfund site (Massachusetts, USA), contaminated with polychlorinated biphenyls (PCBs), were resuspended under different water column redox conditions: untreated, oxidative, and reductive. The partitioning of PCBs to the overlying water column was measured with polyethylene samplers and compared to partitioning without resuspension. Greater concentrations of total aqueous (freely dissolved + dissolved organic carbon (DOC)-associated) PCBs were found in all resuspended treatments for PCBs with mid-range K(OW)s, but no difference was observed in total aqueous concentrations among different redox conditions. The magnitude of increased concentrations depended on resuspension time and congener K(OW), but ranged from approximately one to eight times those found without resuspension. In a parallel study, DOC was flocculated and removed from smaller-scale NBH sediment resuspensions. In situ K(DOC)s were determined and used to calculate freely dissolved and DOC-associated fractions of the increase in total aqueous PCB concentrations due to resuspension. The importance of DOC-associated PCBs increased with increasing K(OW). In situ K(DOC)s were approximately one to two orders of magnitude greater than those calculated with a commonly used linear free energy relationship (LFER). The present study demonstrates that resuspension of contaminated sediments releases PCBs to the water column, of which a significant fraction are DOC-associated (e.g., 28, 65, and 90% for PCBs 28, 66, and 110, respectively). Results also imply that site-specific PCB K(DOC)s are superior to those calculated with generic LFERs. © 2010 SETAC.

  17. Understanding Reef Flat Sediment Regimes and Hydrodynamics can Inform Erosion Mitigation on Land

    Directory of Open Access Journals (Sweden)

    Lida Tenkova Teneva

    2016-01-01

    Full Text Available Coral reefs worldwide are affected by excessive sediment and nutrient delivery from adjacent watersheds. Land cover and land use changes contribute to reef ecosystem degradation, which in turn, diminish many ecosystem services, including coastal protection, recreation, and food provisioning. The objectives of this work were to understand the role of coastal oceanic and biophysical processes in mediating the effects of sedimentation in shallow reef environments, and to assess the efficacy of land-based sediment remediation in the coastal areas near Maunalei reef, Lāna’i Island, Hawai’i. To the best of our knowledge, this was the first study of sediment dynamics on an east-facing (i.e., facing the trade winds reef in the Hawaiian Islands. We developed ridge-to-reef monitoring systems at two paired stream bed-to-reef sites, where one of the reef sites was adjacent to a community stream sediment remediation project. We found that the two reef sites were characterized by different processes that affected the sediment removal rates; the two sites were also exposed to different amounts of sediment runoff. The community stream sediment remediation project appeared to keep at least 77 tonnes of sediment off the reef flat in one wet season. We found that resuspension of sediments on this reef was similar to that on north-facing and south-facing reefs that also are exposed to the trade winds. We posit that sites with slower sediment removal rates due to slower current velocities or high resuspension rates will require more-robust sediment capture systems on land to reduce sediment input rates and maximize potential for reef health recovery. This suggests that interventions such as local sediment remediation and watershed restoration may mitigate sediment delivery to coral reefs, but these interventions are more likely to be effective if they account for how adjacent coastal oceanographic processes distribute, accumulate, or advect sediment away from

  18. Physical-chemical characterization of sediments from Lapa Grande de Taquaracu archaeological site, MG

    International Nuclear Information System (INIS)

    Tudela, Diego Renan Giclioti

    2013-01-01

    In this project the elemental concentrations of Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn were determined by instrumental neutron activation analysis (INAA) in 60 sediment samples from Lapa Grande de Taquaracu archaeological site, located in MG State. The samples were provided by Dr. Astolfo Gomes de Mello Araujo from the Museum of Archaeology and Ethnology, University of Sao Paulo. This site is a palaeoindian rockshelter located near Lagoa Santa karst with characteristics which could be used to test karst abandonment model during the Middle Holocene related to dry conditions. The results of elemental concentrations, interpreted by multivariate statistical analysis, showed the formation of three different compositional and well-defined groups. The variable selection study by means of Procrusts analysis was also carried out. X-ray diffraction (XRD) analyses were also performed in 8 samples to study their mineralogical composition and they showed that there are distinctions in crystalline structure between the samples of the three elemental compositional groups, being quartz, calcite, dolomite and mica the main crystalline phases present in the samples. (author)

  19. Calibration and application of the branched GDGT temperature proxy on East African lake sediments

    NARCIS (Netherlands)

    Loomis, S.E.; Russell, J.M.; Ladd, B.; Street-Perrott, F.A.; Sinninghe Damsté, J.S.

    2012-01-01

    Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are a novel proxy for mean annual air temperature (MAAT) and have the potential to be broadly applicable to climate reconstruction using lacustrine sediments. Several calibrations have been put forth relating brGDGT distributions to MAAT using

  20. Biological and chemical characterization of metal bioavailability in sediments from Lake Roosevelt, Columbia River, Washington, USA

    Science.gov (United States)

    Besser, J.M.; Brumbaugh, W.G.; Ivey, C.D.; Ingersoll, C.G.; Moran, P.W.

    2008-01-01

    We studied the bioavailability and toxicity of copper, zinc, arsenic, cadmium, and lead in sediments from Lake Roosevelt (LR), a reservoir on the Columbia River in Washington, USA that receives inputs of metals from an upstream smelter facility. We characterized chronic sediment toxicity, metal bioaccumulation, and metal concentrations in sediment and pore water from eight study sites: one site upstream in the Columbia River, six sites in the reservoir, and a reference site in an uncontaminated tributary. Total recoverable metal concentrations in LR sediments generally decreased from upstream to downstream in the study area, but sediments from two sites in the reservoir had metal concentrations much lower than adjacent reservoir sites and similar to the reference site, apparently due to erosion of uncontaminated bank soils. Concentrations of acid-volatile sulfide in LR sediments were too low to provide strong controls on metal bioavailability, and selective sediment extractions indicated that metals in most LR sediments were primarily associated with iron and manganese oxides. Oligochaetes (Lumbriculus variegatus) accumulated greatest concentrations of copper from the river sediment, and greatest concentrations of arsenic, cadmium, and lead from reservoir sediments. Chronic toxic effects on amphipods (Hyalella azteca; reduced survival) and midge larvae (Chironomus dilutus; reduced growth) in whole-sediment exposures were generally consistent with predictions of metal toxicity based on empirical and equilibrium partitioning-based sediment quality guidelines. Elevated metal concentrations in pore waters of some LR sediments suggested that metals released from iron and manganese oxides under anoxic conditions contributed to metal bioaccumulation and toxicity. Results of both chemical and biological assays indicate that metals in sediments from both riverine and reservoir habitats of Lake Roosevelt are available to benthic invertebrates. These findings will be used as

  1. Use of an ADCP to compute suspended-sediment discharge in the tidal Hudson River, New York

    Science.gov (United States)

    Wall, Gary R.; Nystrom, Elizabeth A.; Litten, Simon

    2006-01-01

    Acoustic Doppler current profilers (ADCPs) can provide data needed for computation of suspended-sediment discharge in complex river systems, such as tidal rivers, in which conventional methods of collecting time-series data on suspended-sediment concentration (SSC) and water discharge are not feasible. Although ADCPs are not designed to measure SSC, ADCP data can be used as a surrogate under certain environmental conditions. However, the software for such computation is limited, and considerable post-processing is needed to correct and normalize ADCP data for this use. This report documents the sampling design and computational procedure used to calibrate ADCP measures of echo intensity to SSC and water velocity to discharge in the computation of suspended-sediment discharge at the study site on the Hudson River near Poughkeepsie, New York. The methods and procedures described may prove useful to others doing similar work in different locations; however, they are specific to this study site and may have limited applicability elsewhere.

  2. Heavy metal contamination in sand and sediments near to disposal site of reject brine from desalination plant, Arabian Gulf: Assessment of environmental pollution.

    Science.gov (United States)

    Alshahri, Fatimh

    2017-01-01

    Accumulation of heavy metals in environment may cause series potential risk in the living system. This study was carried out to investigate heavy metal contamination in sand samples and sediments along the beach near to disposal site of reject brine from Alkhobar desalination plant, which is one of the oldest and largest reverse osmosis desalination plants in eastern Saudi Arabia, Arabian Gulf. Fourteen heavy metals (U, Ca, Fe, Al, Ti, Sr, Rb, Ni, Pb, Cd, Cr, Cu, As, and Zr) were measured using gamma-ray spectrometry, atomic absorption spectrometer (AAS) and energy dispersive X-ray fluorescence spectrometer (EDX). The obtained data revealed that the concentrations of these metals were higher than the values in sediment and soil for other studies in Arabian Gulf. Furthermore, the mean values of Fe, Mn, Cr, Cu, As, Sr, and Zr concentrations in sand and sediments were higher than the geochemical background values in shale. The contamination factor (CF), modified degree of contamination (mC d ) and pollution load index (PLI) were assessed. According to contamination factors (CF > 1), the results showed elevated levels of Cu, Cr, Mn, Zr, and As in all samples. The highest value of contamination factor was found for As. Based on PLI (PLI > 1), the values of all sampling sites indicate a localized pollution in the study area. Current study could be useful as baseline data for heavy metals in sand and sediments nearby a desalination plant.

  3. Johnson City 10 x 20 NTMS area, Kentucky, North Carolina, Tennessee, and Virginia: data report (abbreviated). National Uranium Resource Evaluation program, hydrogeochemical and stream sediment reconnaissance

    International Nuclear Information System (INIS)

    Fay, W.M.

    1980-10-01

    Results of ground water and stream sediment reconnaissance in the National Topographic Map Series (NTMS) Johnson City 1 0 x 2 0 quadrangle are presented. Surface sediment samples were collected at 959 sites. Ground water samples were collected at 1099 sites. Neutron activation analysis results are given for uranium and 16 other elements in sediments, and for uranium and 8 other elements in ground water. Data from ground water sites include: (1) water chemistry measurements (pH, conductivity, and alkalinity); (2) physical measurements where applicable (water temperature, well description, etc.); and (3) elemental analyses (U, Al, Br, Cl, Dy, F, Mn, Na, and V). Data from sediment sites include: (1) stream water chemistry measurements; and (2) elemental analyses for sediment samples (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Sample site descriptors (stream characteristics, vegetation, etc.) are given. Areal distribution maps, histograms, and cumulative frequency plots for most elements and for U/Th and U/Hf ratios are included on the microfiche. The Johnson City Quadrangle is underlain by Precambrian cyrstalline rocks in the southeastern corner of the quadrangle and by Paleozoic sediments in the remainder of the quadrangle. The highest uranium concentrations in sediments (up to 22 ppM) are in samples from the Precambrian crystalline rock areas. These samples also have high thorium concentrations suggesting that most of the uranium is in resistate minerals such as monazite. The U/Th ratios in sediment samples are generaly low with the higher values (up to 2.07) mostly within the lower Paleozoic sediments, particularly the Copper Ridge Dolomite. The uranium concentration in ground water is also highest in the lower Paleozoic sediments

  4. Sedimentation in a Submarine Seamount Apron at Site U1431, International Ocean Discovery Program Expedition 349, South China Sea

    Science.gov (United States)

    Dadd, K. A.; Clift, P. D.; Hyun, S.; Jiang, T.; Liu, Z.

    2014-12-01

    International Ocean Discovery Program (IODP) Expedition 349 Site U1431 is located near the relict spreading ridge in the East Subbasin of the South China Sea. Holes at this site were drilled close to seamounts and intersected the volcaniclastic apron. Volcaniclastic breccia and sandstone at Site U1431 are dated as late middle Miocene to early late Miocene (~8-13 Ma), suggesting a 5 m.y. duration of seamount volcanism. The apron is approximately 200 m thick and is sandwiched between non-volcaniclastic units that represent the background sedimentation. These comprise dark greenish gray clay, silt, and nannofossil ooze interpreted as turbidite and hemipelagic deposits that accumulated at abyssal water depths. At its base, the seamount sequence begins with dark greenish gray sandstone, siltstone, and claystone in upward fining sequences interpreted as turbidites intercalated with minor intervals of volcaniclastic breccia. Upsection the number and thickness of breccia layers increases with some beds up to 4.8 m and possibly 14.5 m thick. The breccia is typically massive, ungraded, and poorly sorted with angular to subangular basaltic clasts, as well as minor reworked subrounded calcareous mudstone, mudstone, and sandstone clasts. Basaltic clasts include nonvesicular aphyric basalt, sparsely vesicular aphyric basalt, highly vesicular aphyric basalt, and nonvesicular glassy basalt. Mudstone clasts are clay rich and contain foraminifer fossils. The matrix comprises up to 40% of the breccia beds and is a mix of clay, finer grained altered basalt clasts, and mafic vitroclasts with rare foraminifer fossils. Some layers have calcite cement between clasts. Volcaniclastic sandstone and claystone cycles interbedded with the breccia layers have current ripples and parallel laminations indicative of high-energy flow conditions during sedimentation. The breccia beds were most likely deposited as a series of debris flows or grain flows. This interpretation is supported by their

  5. A comparison of sediment toxicity test methods at three Great Lake Areas of Concern

    Science.gov (United States)

    Burton, G. Allen; Ingersoll, Christopher G.; Burnett, LouAnn C.; Henry, Mary; Hinman, Mark L.; Klaine, Stephen J.; Landrum, Peter F.; Ross, Phillipe; Tuchman, Marc

    1996-01-01

    The significance of sediment contamination is often evaluated using sediment toxicity (bioassay) testing. There are relatively few “standardized” test methods for evaluating sediments. Popular sediment toxicity methods examine the extractable water (elutriate), interstitial water, or whole (bulk) sediment phases using test species spanning the aquatic food chain from bacteria to fish. The current study was designed to evaluate which toxicity tests were most useful in evaluations of sediment contamination at three Great Lake Areas of Concern. Responses of 24 different organisms including fish, mayflies, amphipods, midges, cladocerans, rotifers, macrophytes, algae, and bacteria were compared using whole sediment or elutriate toxicity assays. Sediments from several sites in the Buffalo River, Calumet River (Indiana Harbor), and Saginaw River were tested, as part of the U.S. Environmental Protection Agency's (USEPA) Assessment and Remediation of Contaminated Sediments (ARCS) Project. Results indicated several assays to be sensitive to sediment toxicity and able to discriminate between differing levels of toxicity. Many of the assay responses were significantly correlated to other toxicity responses and were similar based on factor analysis. For most applications, a test design consisting of two to three assays should adequately detect sediment toxicity, consisting of various groupings of the following species: Hyalella azteca, Ceriodaphnia dubia, Chironomus riparius, Chironomus tentans, Daphnia magna, Pimephales promelas, Hexagenia bilineata, Diporeia sp., Hydrilla verticillata, or Lemna minor.

  6. Post-monsoon equilibrium beach profiles and longshore sediment transport rates at Candolim, Miramar and Keri beaches of Goa, India.

    Digital Repository Service at National Institute of Oceanography (India)

    Jayakumar, S.; Yadhunath, E.M.; Jishad, M.; Gowthaman, R.; Rajasekaran, C; Pednekar, P.S.

    ) and the profile shape factor m, which are inversely proportional to each other, have been analysed for their application to the study site. Also, the variation of these two parameters with beach slope and grain size is studied. Longshore sediment...

  7. Quantifying sediment-associated metal dispersal using Pb isotopes: Application of binary and multivariate mixing models at the catchment-scale

    International Nuclear Information System (INIS)

    Bird, Graham; Brewer, Paul A.; Macklin, Mark G.; Nikolova, Mariyana; Kotsev, Tsvetan; Mollov, Mihail; Swain, Catherine

    2010-01-01

    In this study Pb isotope signatures were used to identify the provenance of contaminant metals and establish patterns of downstream sediment dispersal within the River Maritsa catchment, which is impacted by the mining of polymetallic ores. A two-fold modelling approach was undertaken to quantify sediment-associated metal delivery to the Maritsa catchment; employing binary mixing models in tributary systems and a composite fingerprinting and mixing model approach in the wider Maritsa catchment. Composite fingerprints were determined using Pb isotopic and multi-element geochemical data to characterize sediments delivered from tributary catchments. Application of a mixing model allowed a quantification of the percentage contribution of tributary catchments to the sediment load of the River Maritsa. Sediment delivery from tributaries directly affected by mining activity contributes 42-63% to the sediment load of the River Maritsa, with best-fit regression relationships indicating that sediments originating from mining-affected tributaries are being dispersed over 200 km downstream. - Pb isotopic evidence used to quantify sediment-associated metal delivery within a mining-affected river catchment.

  8. Contamination of port zone sediments by metals from Large Marine Ecosystems of Brazil.

    Science.gov (United States)

    Buruaem, Lucas M; Hortellani, Marcos A; Sarkis, Jorge E; Costa-Lotufo, Leticia V; Abessa, Denis M S

    2012-03-01

    Sediment contamination by metals poses risks to coastal ecosystems and is considered to be problematic to dredging operations. In Brazil, there are differences in sedimentology along the Large Marine Ecosystems in relation to the metal distributions. We aimed to assess the extent of Al, Fe, Hg, Cd, Cr, Cu, Ni, Pb and Zn contamination in sediments from port zones in northeast (Mucuripe and Pecém) and southeast (Santos) Brazil through geochemical analyses and sediment quality ratings. The metal concentrations found in these port zones were higher than those observed in the continental shelf or the background values in both regions. In the northeast, metals were associated with carbonate, while in Santos, they were associated with mud. Geochemical analyses showed enrichments in Hg, Cd, Cu, Ni and Zn, and a simple application of international sediment quality guidelines failed to predict their impacts, whereas the use of site-specific values that were derived by geochemical and ecotoxicological approaches seemed to be more appropriate in the management of the dredged sediments. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Bacterial reduction of selenium in coal mine tailings pond sediment

    Energy Technology Data Exchange (ETDEWEB)

    Siddique, T.; Arocena, J.M.; Thring, R.W.; Zhang, Y.Q. [University of North British Columbia, Prince George, BC (Canada)

    2007-05-15

    Sediment from a storage facility for coal tailings solids was assessed for its capacity to reduce selenium (Se) by native bacterial community. One Se{sup 6+}-reducing bacterium Enterobacter hormaechei (Tar11) and four Se{sup 4+}-reducing bacteria, Klebsiella pneumoniae (Tar1), Pseudomonasfluorescens (Tar3), Stenotrophomonas maltophilia (Tar6), and Enterobacter amnigenus (Tar8) were isolated from the sediment. Enterobacter horinaechei removed 96% of the added Se{sup 6+} (0.92 mg L{sup -1} from the effluents when Se6+ was determined after 5 d of incubation. Analysis of the red precipitates showed that Se{sup 6+} reduction resulted in the formation of spherical particles ({lt}1.0 {mu} m) of Se 0 as observed under scanning electron microscope (SEM) and confirmed by EDAX. Selenium speciation was performed to examine the fate of the added Se{sup 6+} in the sediment with or without addition of Enterobacter hormaechei cells. More than 99% of the added Se{sup 6+} (about 2.5 mg L{sup -1}) was transformed in the nonsterilized sediment (without Enterobacter hormaechei cells) as well as in the sterilized (heat-killed) sediment (with Enterobacter hormaechei cells). The results of this study suggest that the lagoon sediments at the mine site harbor Se{sup 6+}- and Se{sup 4+} -reducing bacteria and may be important sinks for soluble Se (Se{sup 6+} and Se{sup 4+}). Enterobacter hormaechei isolated from metal-contaminated sediment may have potential application in removing Se from industrial effluents.

  10. Technical guidelines for environmental dredging of contaminated sediments

    Science.gov (United States)

    2008-09-01

    This report provides technical guidelines for evaluating : environmental dredging as a sediment remedy component. This document : supports the Contaminated Sediment Remediation Guidance for : Hazardous Waste Sites, released by the U.S. Environmental ...

  11. Hanford Site Solid Waste Landfill permit application

    International Nuclear Information System (INIS)

    1991-01-01

    Daily activities at the Hanford Site generate sanitary solid waste (nonhazardous and nonradioactive) that is transported to and permanently disposed of at the Hanford Site Solid Waste Landfill. This permit application describes the manner in which the solid Waste Landfill will be operated under Washington State Department of Ecology Minimum Functional Standards for Solid Waste Handling, Washington Administrative Code 173-304. The solid Waste Landfill is owned by the US Department of Energy -- Richland Operations Office and is used for disposal of solid waste generated at the US Department of Energy Hanford Site. The jurisdictional health department's permit application form for the Solid Waste Landfill is provided in Chapter 1.0. Chapter 2.0 provides a description of the Hanford Site and the Solid Waste Landfill and reviews applicable locational, general facility, and landfilling standards. Chapter 3.0 discusses the characteristics and quantity of the waste disposed of in the Solid Waste Landfill. Chapter 4.0 reviews the regional and site geology and hydrology and the groundwater and vadose zone quality beneath the landfill. Chapters 5.0, 6.0, and 7.0 contain the plan of operation, closure plan, and postclosure plan, respectively. The plan of operation describes the routine operation and maintenance of the Solid Waste Landfill, the environmental monitoring program, and the safety and emergency plans. Chapter 5.0 also addresses the operational cover, environmental controls, personnel requirements, inspections, recordkeeping, reporting, and site security. The postclosure plan describes requirements for final cover maintenance and environmental monitoring equipment following final closure. Chapter 8.0 discusses the integration of closure and postclosure activities between the Solid Waste Landfill and adjacent Nonradioactive Dangerous Waste Landfill. 76 refs., 48 figs, 15 tabs

  12. Heavy metal pollutants in surficial sediments from different coastal sites in Aden Governorate, Yemen

    International Nuclear Information System (INIS)

    Ali, Anis Ahmed; Baharoon Aqil Abdulrahman

    2004-01-01

    Concentrations of Gd, Pb, Zn, Cu, Ni, Co, Cr, Mn and Fe in surficial sediments (<63μm) from the shores in Aden Governorate were determined by atomic absorption spectrophotometry method. The obtained concentration data show significant regional variations concerning both the total and leachable metals in sediments. Total metal concentrations of Cd and Pb were greatest in sediments from labor Island; Cu, Cr, and Fe occurred in the highest levels in Bandar Fuqum sediments, while maximum levels of Mn, Co, and Ni were observed in sediments from Sahel Abyan and Fuqum. Labile, easily extractable species of metals such as Cd and Pb, are similar to their total concentrations, and additionally Cu, Zn, Cr, and Fe were found in the highest concentrations in sediments from labor Island. Sediments from Sahel Abyan and Khawr Bir Ahmed were characterized by a maximum accumulation of bioavailable species of Co and Mn, respectively. The linear regression slopes for metals correlated were <1, this explains the slow enrichment of these metals in the sediments, and attributes their geological nature. (author)

  13. Regulatory Review of Early Site Permit Applications

    International Nuclear Information System (INIS)

    Scott, Michael L.

    2004-01-01

    The U.S. Nuclear Regulatory Commission (NRC) has received and is reviewing three applications for early site permits (ESPs). The ESP process allows early resolution of site-related issues affecting possible construction and operation of a new nuclear power plant. The nuclear industry views a successful and predictable ESP process as an important step in assessing whether to seek authorization to construct and operate a new generation of nuclear power reactors in the United States. Because consideration of ESP applications is a first-of-a-kind activity, a number of issues have emerged prior to and during the reviews of the first three applications. Issues have included the need for design information at the ESP stage, accident analyses, quality assurance, and seismic analyses. The NRC has been working to resolve identified issues to support a Commission decision on whether to issue an ESP approximately 33-37 months after receipt of each ESP application. (authors)

  14. Neogene sedimentation on the outer continental margin, southern Bering Sea

    Science.gov (United States)

    Vallier, T.L.; Underwood, M.B.; Gardner, J.V.; Barron, J.A.

    1980-01-01

    Neogene sedimentary rocks and sediments from sites on the outer continental margin in the southern Bering Sea and on the Alaska Peninsula are dominated by volcanic components that probably were eroded from an emergent Aleutian Ridge. A mainland continental source is subordinate. Most sediment in the marine environment was transported to the depositional sites by longshore currents, debris flows, and turbidity currents during times when sea level was near the outermost continental shelf. Fluctuations of sea level are ascribed both to worldwide glacio-eustatic effects and to regional vertical tectonics. Large drainage systems, such as the Yukon and Kuskokwim Rivers, had little direct influence on sedimentation along the continental slope and Unmak Plateau in the southern Bering Sea. Sediments from those drainage systems probably were transported to the floor of the Aleutian Basin, to the numerous shelf basins that underlie the outer continental shelf, and to the Arctic Ocean after passing through the Bering Strait. Environments of deposition at the sites along the outer continental margin have not changed significantly since the middle Miocene. The site on the Alaska Peninsula, however, is now emergent following shallow-marine and transitional sedimentation during the Neogene. ?? 1980.

  15. Potential Release Site Sediment Concentrations Correlated to Storm Water Station Runoff through GIS Modeling

    International Nuclear Information System (INIS)

    McLean, C.T.

    2005-01-01

    This research examined the relationship between sediment sample data taken at Potential Release Sites (PRSs) and storm water samples taken at selected sites in and around Los Alamos National Laboratory (LANL). The PRSs had been evaluated for erosion potential and a matrix scoring system implemented. It was assumed that there would be a stronger relationship between the high erosion PRSs and the storm water samples. To establish the relationship, the research was broken into two areas. The first area was raster-based modeling, and the second area was data analysis utilizing the raster based modeling results and the sediment and storm water sample results. Two geodatabases were created utilizing raster modeling functions and the Arc Hydro program. The geodatabase created using only Arc Hydro functions contains very fine catchment drainage areas in association with the geometric network and can be used for future contaminant tracking. The second geodatabase contains sub-watersheds for all storm water stations used in the study along with a geometric network. The second area of the study focused on data analysis. The analytical sediment data table was joined to the PRSs spatial data in ArcMap. All PRSs and PRSs with high erosion potential were joined separately to create two datasets for each of 14 analytes. Only the PRSs above the background value were retained. The storm water station spatial data were joined to the table of analyte values that were either greater than the National Pollutant Discharge Elimination System (NPDES) Multi-Sector General Permit (MSGP) benchmark value, or the Department of Energy (DOE) Drinking Water Defined Contribution Guideline (DWDCG). Only the storm water stations were retained that had sample values greater than the NPDES MSGP benchmark value or the DOE DWDCG. Separate maps were created for each analyte showing the sub-watersheds, the PRSs over background, and the storm water stations greater than the NPDES MSGP benchmark value or the

  16. Contamination in sediments, bivalves and sponges of McMurdo Sound, Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Negri, Andrew [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia)]. E-mail: a.negri@aims.gov.au; Burns, Kathryn [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia); Boyle, Steve [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia); Brinkman, Diane [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia); Webster, Nicole [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia); Biological Sciences, University of Canterbury, Christchurch (New Zealand)

    2006-10-15

    This study examined the concentrations of total hydrocarbons (THC), polychlorinated biphenyls (PCB), polyaromatic hydrocarbons (PAH), and trace metals (Cu, Zn, Cd, Pb, Hg and As) in marine sediments off Scott Base (NZ) and compared them with sediments near the highly polluted McMurdo Station (US) as well as less impacted sites including Turtle Rock and Cape Evans. The Antarctic mollusc, Laternula elliptica and three common sponge species were also analysed for trace metals. The mean THC concentration in sediments from Scott Base was 3 fold higher than the pristine site, Turtle Rock, but 10 fold lower than samples from McMurdo Station. McMurdo Station sediments also contained the highest concentrations of PAHs, PCBs and the trace metals, Cu, Zn, Pb, Cd and Hg. Copper was significantly higher in bivalves from McMurdo Station than other sites. Trace metal concentrations in sponges were generally consistent within sites but no spatial patterns were apparent. - Analyses of Antarctic marine sediments, bivalves and sponges revealed strong PAH, PCB and trace metal gradients in McMurdo Sound.

  17. Contamination in sediments, bivalves and sponges of McMurdo Sound, Antarctica

    International Nuclear Information System (INIS)

    Negri, Andrew; Burns, Kathryn; Boyle, Steve; Brinkman, Diane; Webster, Nicole

    2006-01-01

    This study examined the concentrations of total hydrocarbons (THC), polychlorinated biphenyls (PCB), polyaromatic hydrocarbons (PAH), and trace metals (Cu, Zn, Cd, Pb, Hg and As) in marine sediments off Scott Base (NZ) and compared them with sediments near the highly polluted McMurdo Station (US) as well as less impacted sites including Turtle Rock and Cape Evans. The Antarctic mollusc, Laternula elliptica and three common sponge species were also analysed for trace metals. The mean THC concentration in sediments from Scott Base was 3 fold higher than the pristine site, Turtle Rock, but 10 fold lower than samples from McMurdo Station. McMurdo Station sediments also contained the highest concentrations of PAHs, PCBs and the trace metals, Cu, Zn, Pb, Cd and Hg. Copper was significantly higher in bivalves from McMurdo Station than other sites. Trace metal concentrations in sponges were generally consistent within sites but no spatial patterns were apparent. - Analyses of Antarctic marine sediments, bivalves and sponges revealed strong PAH, PCB and trace metal gradients in McMurdo Sound

  18. Hillslope runoff and sediment transport in south east Spain

    Science.gov (United States)

    Bracken (Nee Bull), L. J.; Kirkby, M. J.

    2003-04-01

    Runoff from semi-arid hillslopes in SE Spain is generated very selectively at all scales. Site response at the 1 m2 scale may be described by the dynamics of local infiltration and crusting, defining Hydrologically Similar Surfaces (HYSS), which are strongly associated with soil type and vegetation cover. This study reports the use of several reconnaissance methods to define HYSS consistently. These methods are (1) the use of small sediment traps which disturb the surface minimally,(2) the use of painted lines and (3) the identification of Morphological Zones associated with different levels of runoff and sediment transport. Five monitoring sites were established on hillslope concavities in two semi-arid catchments in South East Spain. Rainfall data were also collected from the nearest gauge established during previous research. Results show that a storm event in the Rambla de Nogalte on the 30th of June of 83.0 mm was responsible for a maximum runoff depth of 12 cm and a maximum hillslope sediment transport of 1886 cm3 m-1. The same storm in the Rambla de Torrealvilla produced 53.4 mm of rainfall on the 1st of July 2002, had a maximum runoff depth of 26 cm and was responsible for a maximum hillslope sediment transport of 2311 cm3 m-1. In general sediment transport rate and sediment travel distance increased with the distance downslope into the hillslope hollow, and these were related to the maximum depth of flow produced over the hillside. Very little sediment movement occurred directly downslope of bushes as was expected. No significant relationships were established between sediment transport and slope angle or vegetation cover. However, sediment transport and depth of runoff varied with lithology, with marl sites producing the most runoff and sediment transport. The site located on red schist was particularly unresponsive to rainfall and did not experience much sediment transport. Initial models for the response of larger areas suggest that runoff is controlled

  19. Effects of ghost shrimp on zinc and cadmium in sediments from Tampa Bay, FL

    Science.gov (United States)

    Klerks, P.L.; Felder, D.L.; Strasser, K.; Swarzenski, P.W.

    2007-01-01

    This study investigated the effects that ghost shrimp have on the distribution of metals in sediment. We measured levels of HNO3-extractable zinc and cadmium in surface sediment, in ghost shrimp burrow walls and in sediment ejected by the ghost shrimp from their burrows, at five sandy intertidal sites in Tampa Bay. Ghost shrimp densities and their rate of sediment ejection were also quantified, as were sediment organic content and silt + clay content. Densities of ghost shrimp (Sergio trilobata and Lepidophthalmus louisianensis) averaged 33/m2 at our sites, and they ejected sediment at an average rate of 28 g/burrow/day. Levels of both Zn and Cd were significantly higher in burrow walls than in surface sediments. Sediment ejected by the shrimp from their burrows had elevated levels of Zn (relative to surface sediments) at one of the sites. Sediment organic content and silt + clay content were higher in burrow-wall sediments than in ejected sediment, which in turn tended to have values above those of surface sediments. Differences in levels of HNO3-extractable Zn and Cd among sediment types may be a consequence of these sediments differing in other physiochemical characteristics, though the differences in metal levels remained statistically significant for some sites after correcting for differences in organic content and silt + clay content. We conclude that the presence of ghost shrimp burrows contributes to spatial heterogeneity of sedimentary metal levels, while the ghost shrimp bioturbation results in a significant flux of metals to the sediment surface and is expected to decrease heterogeneity of metal levels in sedimentary depth profiles.

  20. A GUIDED SWAT MODEL APPLICATION ON SEDIMENT YIELD MODELING IN PANGANI RIVER BASIN: LESSONS LEARNT

    Directory of Open Access Journals (Sweden)

    Preksedis Marco Ndomba

    2008-12-01

    Full Text Available The overall objective of this paper is to report on the lessons learnt from applying Soil and Water Assessment Tool (SWAT in a well guided sediment yield modelling study. The study area is the upstream of Pangani River Basin (PRB, the Nyumba Ya Mungu (NYM reservoir catchment, located in the North Eastern part of Tanzania. It should be noted that, previous modeling exercises in the region applied SWAT with preassumption that inter-rill or sheet erosion was the dominant erosion type. In contrast, in this study SWAT model application was guided by results of analysis of high temporal resolution of sediment flow data and hydro-meteorological data. The runoff component of the SWAT model was calibrated from six-years (i.e. 1977–1982 of historical daily streamflow data. The sediment component of the model was calibrated using one-year (1977–1988 daily sediment loads estimated from one hydrological year sampling programme (between March and November, 2005 rating curve. A long-term period over 37 years (i.e. 1969–2005 simulation results of the SWAT model was validated to downstream NYM reservoir sediment accumulation information. The SWAT model captured 56 percent of the variance (CE and underestimated the observed daily sediment loads by 0.9 percent according to Total Mass Control (TMC performance indices during a normal wet hydrological year, i.e., between November 1, 1977 and October 31, 1978, as the calibration period. SWAT model predicted satisfactorily the long-term sediment catchment yield with a relative error of 2.6 percent. Also, the model has identified erosion sources spatially and has replicated some erosion processes as determined in other studies and field observations in the PRB. This result suggests that for catchments where sheet erosion is dominant SWAT model may substitute the sediment-rating curve. However, the SWAT model could not capture the dynamics of sediment load delivery in some seasons to the catchment outlet.

  1. A GUIDED SWAT MODEL APPLICATION ON SEDIMENT YIELD MODELING IN PANGANI RIVER BASIN: LESSONS LEARNT

    Directory of Open Access Journals (Sweden)

    Preksedis M. Ndomba

    2008-01-01

    Full Text Available The overall objective of this paper is to report on the lessons learnt from applying Soil and Water Assessment Tool (SWAT in a well guided sediment yield modelling study. The study area is the upstream of Pangani River Basin (PRB, the Nyumba Ya Mungu (NYM reservoir catchment, located in the North Eastern part of Tanzania. It should be noted that, previous modeling exercises in the region applied SWAT with preassumption that inter-rill or sheet erosion was the dominant erosion type. In contrast, in this study SWAT model application was guided by results of analysis of high temporal resolution of sediment flow data and hydro-meteorological data. The runoff component of the SWAT model was calibrated from six-years (i.e. 1977¿1982 of historical daily streamflow data. The sediment component of the model was calibrated using one-year (1977-1988 daily sediment loads estimated from one hydrological year sampling programme (between March and November, 2005 rating curve. A long-term period over 37 years (i.e. 1969-2005 simulation results of the SWAT model was validated to downstream NYM reservoir sediment accumulation information. The SWAT model captured 56 percent of the variance (CE and underestimated the observed daily sediment loads by 0.9 percent according to Total Mass Control (TMC performance indices during a normal wet hydrological year, i.e., between November 1, 1977 and October 31, 1978, as the calibration period. SWAT model predicted satisfactorily the long-term sediment catchment yield with a relative error of 2.6 percent. Also, the model has identified erosion sources spatially and has replicated some erosion processes as determined in other studies and field observations in the PRB. This result suggests that for catchments where sheet erosion is dominant SWAT model may substitute the sediment-rating curve. However, the SWAT model could not capture the dynamics of sediment load delivery in some seasons to the catchment outlet.

  2. Radiocarbon dating of lake sediments

    OpenAIRE

    Pocevičius, Matas

    2016-01-01

    Matas Pocevičius, Radiocarbon dating of lake sediments, bachelor thesis, Vilnius University, Faculty of Physics, Department of General Physics and Spectroscopy, physics, Vilnius, 45 p., 2016. The aim of this study is to evaluate the possibility of radiocarbon dating application for Tapeliai lake bottom sediments. The literature review discusses topics related to accelerator mass spectrometry, principles of radiocarbon formation, importance of nuclear fallout for 14C, possible applications of ...

  3. Application of Moessbauer spectroscopy to the study of neptunium adsorbed on deep-sea sediments

    International Nuclear Information System (INIS)

    Bennett, B.A.; Rees, L.V.C.

    1987-03-01

    A Neptunium Moessbauer spectrometer (the first in Great Britain) was constructed and the Moessbauer spectra of NpAl Laves phase alloy obtained. Neptunium was sorbed onto a calcareous deep-sea sediment from sea water, using a successive-loading technique. Sorption appeared to be by an equilibrium reaction, and because of the low solubility of neptunium in seawater, this meant that the maximum loading that could be achieved was 8mg 237 Np/g sediment. This proved to be an adequate concentration for Moessbauer measurements and a Moessbauer spectrum was obtained. This showed that most of the neptunium was in exchange sites and not present as precipitates of neptunium compounds. It was probably in the 4+ state indicating that reduction had occurred during sorption. This work has demonstrated that Moessbauer Spectroscopy has great potential as an aid to understanding the mechanism of actinide sorption in natural systems. (author)

  4. Fluvial sediment transport: Analytical techniques for measuring sediment load

    International Nuclear Information System (INIS)

    2005-07-01

    Sediment transport data are often used for the evaluation of land surface erosion, reservoir sedimentation, ecological habitat quality and coastal sediment budgets. Sediment transport by rivers is usually considered to occur in two major ways: (1) in the flow as a suspended load and (2) along the bed as a bed load. This publication provides guidance on selected techniques for the measurement of particles moving in both modes in the fluvial environment. The relative importance of the transport mode is variable and depends on the hydraulic and sedimentary conditions. The potential user is directed in the selection of an appropriate technique through the presentation of operating principles, application guidelines and estimated costs. Techniques which require laboratory analysis are grab sample, pump sample, depth sample, point integrated and radioactive tracers. Techniques which will continuously record data are optical backscattering, nuclear transmission, single frequency acoustic and laser diffraction

  5. Documentation of particle-size analyzer time series, and discrete suspended-sediment and bed-sediment sample data collection, Niobrara River near Spencer, Nebraska, October 2014

    Science.gov (United States)

    Schaepe, Nathaniel J.; Coleman, Anthony M.; Zelt, Ronald B.

    2018-04-06

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers, monitored a sediment release by Nebraska Public Power District from Spencer Dam located on the Niobrara River near Spencer, Nebraska, during the fall of 2014. The accumulated sediment behind Spencer Dam ordinarily is released semiannually; however, the spring 2014 release was postponed until the fall. Because of the postponement, the scheduled fall sediment release would consist of a larger volume of sediment. The larger than normal sediment release expected in fall 2014 provided an opportunity for the USGS and U.S. Army Corps of Engineers to improve the understanding of sediment transport during reservoir sediment releases. A primary objective was to collect continuous suspended-sediment data during the first days of the sediment release to document rapid changes in sediment concentrations. For this purpose, the USGS installed a laser-diffraction particle-size analyzer at a site near the outflow of the dam to collect continuous suspended-sediment data. The laser-diffraction particle-size analyzer measured volumetric particle concentration and particle-size distribution from October 1 to 2 (pre-sediment release) and October 5 to 9 (during sediment release). Additionally, the USGS manually collected discrete suspended-sediment and bed-sediment samples before, during, and after the sediment release. Samples were collected at two sites upstream from Spencer Dam and at three bridges downstream from Spencer Dam. The resulting datasets and basic metadata associated with the datasets were published as a data release; this report provides additional documentation about the data collection methods and the quality of the data.

  6. Characterizing toxicity of metal-contaminated sediments from mining areas

    International Nuclear Information System (INIS)

    Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.

    2015-01-01

    Highlights: • We review methods for testing toxicity of sediments affected by metals. • Toxicity testing provides site-specific assessment of impacts on resident biota. • Goals are to document extent of toxicity and associations with metal exposure. • Need to characterize bioavailability of metals in sediment and pore water. • Toxicity data is basis for guidelines used to predict hazards of metal toxicity. - Abstract: This paper reviews methods for testing the toxicity of metals associated with freshwater sediments, linking toxic effects with metal exposure and bioavailability, and developing sediment quality guidelines. The most broadly applicable approach for characterizing metal toxicity is whole-sediment toxicity testing, which attempts to simulate natural exposure conditions in the laboratory. Standard methods for whole-sediment testing can be adapted to test a wide variety of taxa. Chronic sediment tests that characterize effects on multiple endpoints (e.g., survival, growth, and reproduction) can be highly sensitive indicators of adverse effects on resident invertebrate taxa. Methods for testing of aqueous phases (pore water, overlying water, or elutriates) are used less frequently. Analysis of sediment toxicity data focuses on statistical comparisons between responses in sediments from the study area and responses in one or more uncontaminated reference sediments. For large or complex study areas, a greater number of reference sediments is recommended to reliably define the normal range of responses in uncontaminated sediments – the ‘reference envelope’. Data on metal concentrations and effects on test organisms across a gradient of contamination may allow development of concentration-response models, which estimate metal concentrations associated with specified levels of toxic effects (e.g. 20% effect concentration or EC20). Comparisons of toxic effects in laboratory tests with measures of impacts on resident benthic invertebrate

  7. Evaluation of PCB bioaccumulation by Lumbriculus variegatus in field-collected sediments

    Science.gov (United States)

    Sediment bioaccumulation tests with Lumbriculus variegatus were performed on polychlorinated biphenyl (PCBs) contaminated sediment samples from the Hudson, Grasse, and Fox Rivers Superfund sites with concurrent measurement of PCB concentrations in sediment interstitial water. Th...

  8. Performance Probability Distributions for Sediment Control Best Management Practices

    Science.gov (United States)

    Ferrell, L.; Beighley, R.; Walsh, K.

    2007-12-01

    Controlling soil erosion and sediment transport can be a significant challenge during the construction process due to the extent and conditions of bare, disturbed soils. Best Management Practices (BMPs) are used as the framework for the design of sediment discharge prevention systems in stormwater pollution prevention plans which are typically required for construction sites. This research focuses on commonly-used BMP systems for perimeter control of sediment export: silt fences and fiber rolls. Although these systems are widely used, the physical and engineering parameters describing their performance are not well understood. Performance expectations are based on manufacturer results, but due to the dynamic conditions that exist on a construction site performance expectations are not always achievable in the field. Based on experimental results product performance is shown to be highly variable. Experiments using the same installation procedures show inconsistent sediment removal performances ranging from (>)85 percent to zero. The goal of this research is to improve the determination of off-site sediment yield based on probabilistic performance results of perimeter control BMPs. BMPs are evaluated in the Soil Erosion Research Laboratory (SERL) in the Civil and Environmental Engineering department at San Diego State University. SERL experiments are performed on a 3-m by 10-m tilting soil bed with a soil depth of 0.5 meters and a slope of 33 percent. The simulated storm event consists of 17 mm/hr for 20 minutes followed by 51 mm/hr for 30 minutes. The storm event is based on an ASTM design storm intended to simulate BMP failures. BMP performance is assessed based on experiments where BMPs are installed per manufacture specifications, less than optimal installations, and no treatment conditions. Preliminary results from 30 experiments are presented and used to develop probability distributions for BMP sediment removal efficiencies. The results are then combined with

  9. Biodegradation studies of diesel-contaminated soils and sediments

    International Nuclear Information System (INIS)

    Schlauch, M.; Clark, D.

    1992-01-01

    Radian Corporation is currently remediating the Atchison, Topeka and Sante Fe Railway Superfund site in Clovis, New Mexico. Biodegradation of the petroleum hydrocarbon-contaminated soils and sediments was chosen as the remedial alternative. In order to evaluate the optimum conditions for full-scale bioremediation at this site, Radian designed and implemented various laboratory and field studies. The initial laboratory treatability study was conducted to determine if hydrocarbons in both soils and sediments could be biodegraded using indigenous microorganisms, and determine that the soil were biodegradable, while the sediments were not due to inhibitory factors. To further evaluate the biodegradability6 of the sediments, a laboratory study was initiated which introduced chloride-resistant microbes. The study showed that the sediment bioremediation was possibly by utilizing these microbes; however, the cost was not favorable. Finally, a field plot study was initiated to determine how soil biodegradation would proceed in field conditions, to optimize influencing factors such as moisture and nutrient levels and bioseed addition, and to investigate alternate methods of bioremediating the sediments. Results showed that hydrocarbons in the soils biodegraded much faster in the field than in the lab, and that hydrocarbons in sediments applied to biotreated soils containing acclimated microorganisms were successfully biodegraded

  10. Geochemical and physical properties of soils and shallow sediments at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Looney, B.B.; Eddy, C.A.; Ramdeen, M.; Pickett, J. (Savannah River Lab., Aiken, SC (USA)); Rogers, V. (Soil Conservation Service, Aiken, SC (USA). Savannah River Site Savannah River Lab., Aiken, SC (USA)); Scott, M.T.; Shirley, P.A. (Sirrine Environmental Consultants, Greenville, SC (USA))

    1990-08-31

    A program to characterize the geochemical and physical properties of the unimpacted soils and shallow sediments at the Savannah River Site (SRS) has been completed. The maximum, minimum, median, standard deviation, and mean values for metals, radionuclides, inorganic anions, organic compounds, and agricultural indicator parameters are summarized for six soil series that were identified as representative of the 29 soil series at SRS. The soils from unimpacted areas of SRS are typical of soils found in moderately aggressive weathering environments, including the southeastern United States. Appendix 8 organic compounds were detected in all samples. Since these constituents are not generally present in soil, this portion of the investigation was intended to assess possible laboratory artifacts. An additional objective of the SRS Soil Study was to determine if the composition of the split spoon sampler biased chemical analysis of the soils. Twenty-five duplicate samples were analyzed for a number of metals, radiological and agricultural parameters, and organics by two laboratories currently contracted with to analyze samples during waste site characterization. In all cases, the absolute values of the average differences are relatively small compared to the overall variability in the population. 31 refs., 14 figs., 48 tabs.

  11. Geochemical and physical properties of soils and shallow sediments at the Savannah River Site

    International Nuclear Information System (INIS)

    Looney, B.B.; Eddy, C.A.; Ramdeen, M.; Pickett, J.; Rogers, V.; Scott, M.T.; Shirley, P.A.

    1990-01-01

    A program to characterize the geochemical and physical properties of the unimpacted soils and shallow sediments at the Savannah River Site (SRS) has been completed. The maximum, minimum, median, standard deviation, and mean values for metals, radionuclides, inorganic anions, organic compounds, and agricultural indicator parameters are summarized for six soil series that were identified as representative of the 29 soil series at SRS. The soils from unimpacted areas of SRS are typical of soils found in moderately aggressive weathering environments, including the southeastern United States. Appendix 8 organic compounds were detected in all samples. Since these constituents are not generally present in soil, this portion of the investigation was intended to assess possible laboratory artifacts. An additional objective of the SRS Soil Study was to determine if the composition of the split spoon sampler biased chemical analysis of the soils. Twenty-five duplicate samples were analyzed for a number of metals, radiological and agricultural parameters, and organics by two laboratories currently contracted with to analyze samples during waste site characterization. In all cases, the absolute values of the average differences are relatively small compared to the overall variability in the population. 31 refs., 14 figs., 48 tabs

  12. Radiotracer and Sealed Source Applications in Sediment Transport Studies

    International Nuclear Information System (INIS)

    2014-01-01

    The investigation of sediment transport in seas and rivers is crucial for civil engineering and littoral protection and management. Coastlines and seabeds are dynamic regions, with sediments undergoing periods of erosion, transport, sedimentation and consolidation. The main causes for erosion in beaches include storms and human actions such as the construction of seawalls, jetties and the dredging of stream mouths. Each of these human actions disrupts the natural flow of sand. Current policies and practices are accelerating the beach erosion process. However, there are viable options available to mitigate this damage and to provide for sustainable coastlines. Radioactive methods can help in investigating sediment dynamics, providing important parameters for better designing, maintaining and optimizing civil engineering structures. Radioisotopes as tracers and sealed sources have been useful and often irreplaceable tools for sediment transport studies. The training course material is based on lecture notes and practical works delivered by many experts in IAEA supported activities. Lectures and case studies were reviewed by a number of specialists in this field

  13. Regional Sediment Management (RSM) Modeling Tools: Integration of Advanced Sediment Transport Tools into HEC-RAS

    Science.gov (United States)

    2014-06-01

    sediment transport within the USACE HEC River Analysis System ( HEC - RAS ) software package and to determine its applicability to Regional Sediment...Management (RSM) challenges. HEC - RAS SEDIMENT MODELING BACKGROUND: HEC - RAS performs (1) one- dimensional (1D) steady and unsteady hydraulic river ...Albuquerque (SPA)), and recently, the USACE RSM Program. HEC - RAS is one of several hydraulic modeling codes available for river analysis in the

  14. Cadmium distribution in coastal sediments and mollusks of the US

    International Nuclear Information System (INIS)

    Apeti, Dennis A.; Lauenstein, Gunnar G.; Riedel, Gerhardt F.

    2009-01-01

    Cadmium (Cd) concentrations in the coastal United States were assessed using the National Status and Trends (NS and T) Mussel Watch dataset, which is based on the analysis of sediments and bivalves collected from 280 sites since 1986. Using the 1997 sediment data, Pearson correlation (r = 0.44, p < 0.0001) suggested that Cd distributions in sediment can, be to some extent, explained by the proximity of sites to population centers. The 2003 tissue data indicated that 'high' Cd concentrations (greater than 5.6 μg/g dry weights [dw] for mussel and 5.4 μg/g dw for oysters) were related to salinity along the East and Gulf coasts. Along the West coast, however, these 'high' sites appeared to be related to upwelling phenomenon. Additionally, sedimentary diagenesis was found to be the most likely explanation of why sediment and mollusk Cd content were not well correlated.

  15. Transuranic Contamination in Sediment and Groundwater at the U.S. DOE Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J.

    2009-08-20

    A review of transuranic radionuclide contamination in sediments and groundwater at the DOE’s Hanford Site was conducted. The review focused primarily on plutonium-239/240 and americium-241; however, other transuranic nuclides were discussed as well, including neptunium-237, plutonium-238, and plutonium-241. The scope of the review included liquid process wastes intentionally disposed to constructed waste disposal facilities such as trenches and cribs, burial grounds, and unplanned releases to the ground surface. The review did not include liquid wastes disposed to tanks or solid wastes disposed to burial grounds. It is estimated that over 11,800 Ci of plutonium-239, 28,700 Ci of americium-241, and 55 Ci of neptunium-237 have been disposed as liquid waste to the near surface environment at the Hanford Site. Despite the very large quantities of transuranic contaminants disposed to the vadose zone at Hanford, only minuscule amounts have entered the groundwater. Currently, no wells onsite exceed the DOE derived concentration guide for plutonium-239/240 (30 pCi/L) or any other transuranic contaminant in filtered samples. The DOE derived concentration guide was exceeded by a small fraction in unfiltered samples from one well (299-E28-23) in recent years (35.4 and 40.4 pCi/L in FY 2006). The primary reason that disposal of these large quantities of transuranic radionuclides directly to the vadose zone at the Hanford Site has not resulted in widespread groundwater contamination is that under the typical oxidizing and neutral to slightly alkaline pH conditions of the Hanford vadose zone, transuranic radionuclides (plutonium and americium in particular) have a very low solubility and high affinity for surface adsorption to mineral surfaces common within the Hanford vadose zone. Other important factors are the fact that the vadose zone is typically very thick (hundreds of feet) and the net infiltration rate is very low due to the desert climate. In some cases where

  16. Tracing the sources of fine sediment in a nickel mining catchment using fallout and geogenic radionuclides (Thio River, New Caledonia)

    Science.gov (United States)

    Evrard, Olivier; Navratil, Oldrich; Lefèvre, Irène; Laceby, J. Patrick; Allenbach, Michel

    2016-04-01

    Soil erosion and subsequent sediment transfer in rivers are exacerbated in tropical regions exposed to heavy rainfall. In New Caledonia, an island located in the southwestern part of the Southern Pacific Ocean, a significant fraction of this sediment is likely originating from tributaries draining nickel mining sites that are known to increase the terrigenous inputs to the rivers and, potentially to UNESCO World Heritage listed coastal lagoons. However, downstream contributions from these tributaries remain to be quantified. A pilot sediment tracing study has therefore been conducted in the 400-km² Thio River catchment. Fallout and geogenic radionuclides have been measured in sediment deposits collected in potential sources, i.e. (i) tributaries draining mines, (ii) tributaries draining 'natural' areas affected by landslides, and (iii) the main stem of the Thio River. Thorium-228 and Caesium-137 provide the best discrimination between sediment originating from the two tributaries. A distribution modelling approach was used to quantify the relative sediment contributions from these tributaries to the Thio River main stem. Results demonstrate that tributaries draining mining sites supply the majority of sediment (67-84%) to the main river. In the future, the validity of these results obtained on sediment deposits collected in April and May 2015 should be verified over a longer time period by applying a similar approach to sediment cores collected in the Thio river deltaic plain. Once validated, this method will be applicable to other catchments draining mines in New Caledonia to design appropriate measures to limit sediment supply to the lagoon.

  17. Precision agriculture - from mapping to site-specific application

    DEFF Research Database (Denmark)

    Pedersen, Søren Marcus; Lind, Kim Martin Hjorth

    2017-01-01

    of each chapter in the book. Each chapter address a different topic starting with an overview of technologies that are currently available, followed by specific Variable-Rate Technologies such as VRT fertilizer application, VRT pesticide application, site-specific irrigation management, Auto...

  18. Modelling post-depositional transport of PAHs in aquatic bed sediments using CoReTranS

    Energy Technology Data Exchange (ETDEWEB)

    Go, Jason [Imperial College London, London (United Kingdom). Dept. of Earth Science and Engineering; Stegemann, Julia A. [Imperial College London, London (United Kingdom). Dept. of Civil, Environmental and Geomatic Engineering

    2012-12-15

    Purpose: Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and persistent contaminants in aquatic bed sediments. A better understanding of their in-bed fate and transport is therefore key in minimising the risk to the environment over time through various remediation and monitoring strategies. Since ecological effects and risks are related to contaminant concentrations, this study developed CoReTranS, a predictive model that simulates one-dimensional organic contaminant reaction and transport in bed sediments. Materials and methods: CoReTranS was benchmarked against analytical solutions of simplified reactive transport models and validated using a published study of marsh sediments contaminated with petroleum-derived hydrocarbons from Wild Harbour, West Falmouth, MA, USA. Results and discussion: The CoReTranS model effectively predicted the vertical distribution of PAHs in the Wild Harbour sediments as confirmed by the modelling results from the published study. The CoReTranS model was also used to interpret results from a published study of PAH-contaminated fjord sediments from Kitimat Arm in British Columbia, Canada. Specific insights into the post-depositional fate and transport of selected PAHs in the Kitimat fjord sediments were obtained by comparing the measured concentration-depth profiles with the numerical results from the CoReTranS model. Key parameters such as effective diffusivity of contaminants and burial velocities of sediment particles were shown to possibly account for the predicted concentrations-depth profiles in the Kitimat fjord sediments. Conclusions: As demonstrated, CoReTranS can simulate reactive transport models in order to predict PAH concentration profiles in porewater under site-specific conditions. The information derived from the use of the CoReTranS model highlighted practical application of such information by engineers to site-specific risk assessment and remediation. (orig.)

  19. Remediation of muddy tidal flat sediments using hot air-dried crushed oyster shells.

    Science.gov (United States)

    Yamamoto, Tamiji; Kondo, Shunsuke; Kim, Kyung-Hoi; Asaoka, Satoshi; Yamamoto, Hironori; Tokuoka, Makoto; Hibino, Tadashi

    2012-11-01

    In order to prove that hot air-dried crushed oyster shells (HACOS) are effective in reducing hydrogen sulfide in muddy tidal flat sediments and increasing the biomass, field experiments were carried out. The concentration of hydrogen sulfide in the interstitial water, which was 16 mg SL(-1) before the application of HACOS, decreased sharply and maintained almost zero in the experimental sites (HACOS application sites) for one year, whereas it was remained at ca. 5 mg SL(-1) in the control sites. The number of macrobenthos individuals increased to 2-4.5 times higher than that in the control site. Using a simple numerical model, the effective periods for suppression of hydrogen sulfide were estimated to be 3.2-7.6 and 6.4-15.2 years for the experimental sites with 4 and 8 tons per 10 × 10 × 0.2m area, respectively. From these results, it is concluded that HACOS is an effective material to remediate muddy tidal flats. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Application of Alkenone 14C-Based chronostratigraphy in carbonate barren sediments on the Peru Margin.

    Science.gov (United States)

    Higginson, M. J.; Altabet, M. A.; Herbert, T. D.

    2003-04-01

    Despite the availability of high-quality sediment cores in key locations, little paleoclimatic information exists for the Peru margin largely because poor carbonate preservation severely restricts the use of traditional carbonate-based proxies for stratigraphy, dating, and paleo-environmental reconstruction. Many sites also include hiatuses produced by the variable influence of undercurrents on sediment accumulation. To overcome these difficulties, we have developed (in collaboration with T. Eglinton, WHOI) a laboratory facility to successfully extract and purify haptophyte-derived alkenones for compound specific 14C AMS dating (modified from OHKOUCHI et al., 2002). This avoids potential problems with dating bulk organic carbon which we assume, even in an upwelling environment as highly productive as the Peru margin, is not a priori solely of marine origin. In a recently collected, mid-Peru Margin core (ODP Leg 201 Site 1228D), comparison of our alkenone 14C dates with bulk sediment organic carbon dates and known stratigraphic markers produces a very well constrained, curvilinear age-depth relationship for at least the last 14 Kyr. A discrete ash layer at Site 1228D with an adjacent alkenone 14C age of 3890 ± 350 yr, is within error identical to the 14C age of a prominent ash layer (3800 ± 50 yr) found west of the large Peruvian El Misti volcano (16^o18'S, 71^o24'W). In summary, these results show that the Peru margin alkenones are autochthonous (i.e. not from an older, distant source) and provide sufficient dating precision to permit, for the first time, high-resolution paleoceanographic studies in this highly important marine province. Based upon this new chronology, synchronous changes in alkenone-derived SST estimates in two of our independently-dated records are the first to record at high-resolution (a) a large LGM-Holocene SST range in the Tropics (up to 7.8 ^oC during brief events in this upwelling location); and (b) sharp coolings (4 ^oC) consistent with

  1. The kinetics of denitrification in permeable sediments

    DEFF Research Database (Denmark)

    Evrard, Victor; Glud, Ronnie N.; Cook, Perran L. M.

    2013-01-01

    Permeable sediments comprise the majority of shelf sediments, yet the rates of denitrification remain highly uncertain in these environments. Computational models are increasingly being used to understand the dynamics of denitrification in permeable sediments, which are complex environments...... on sediments taken from six shallow coastal sites in Port Phillip Bay, Victoria, Australia. The results showed that denitrification commenced rapidly (within 30 min) after the onset of anoxia and the kinetics could be well described by Michaelis-Menten kinetics with half saturation constants (apparent K...... in cohesive sediments despite organic carbon contents one order of magnitude lower for the sediments studied here. The ratio of sediment O-2 consumption to V-max was in the range of 0.02-0.09, and was on average much lower than the theoretical ratio of 0.8. As a consequence, models implemented...

  2. Fractionation and risk assessment of Fe and Mn in surface sediments from coastal sites of Sonora, Mexico (Gulf of California).

    Science.gov (United States)

    Jara-Marini, Martín E; García-Camarena, Raúl; Gómez-Álvarez, Agustín; García-Rico, Leticia

    2015-07-01

    The aim of this study was to evaluate Fe and Mn distribution in geochemical fractions of the surface sediment of four oyster culture sites in the Sonora coast, Mexico. A selective fractionation scheme to obtain five fractions was adapted for the microwave system. Surface sediments were analyzed for carbonates, organic matter contents, and Fe and Mn in geochemical fractions. The bulk concentrations of Fe ranged from 10,506 to 21,918 mg/kg (dry weight, dry wt), and the bulk concentrations of Mn ranged from 185.1 to 315.9 mg/kg (dry wt) in sediments, which was low and considered as non-polluted in all of the sites. The fractionation study indicated that the major geochemical phases for the metals were the residual, as well as the Fe and Mn oxide fractions. The concentrations of metals in the geochemical fractions had the following order: residual > Fe and Mn oxides > organic matter > carbonates > interchangeable. Most of the Fe and Mn were linked to the residual fraction. Among non-residual fractions, high percentages of Fe and Mn were linked to Fe and Mn oxides. The enrichment factors (EFs) for the two metals were similar in the four studied coasts, and the levels of Fe and Mn are interpreted as non-enrichment (EF < 1) because the metals concentrations were within the baseline concentrations. According to the environmental risk assessment codes, Fe and Mn posed no risk and low risk, respectively. Although the concentrations of Fe and Mn were linked to the residual fraction, the levels in non-residual fractions may significantly result in the transference of other metals, depending on several physico-chemical and biological factors.

  3. Soil conservation through sediment trapping: a review

    NARCIS (Netherlands)

    Getahun, M.M.; Keesstra, S.D.; Stroosnijder, L.; Baartman, J.E.M.; Maroulis, J.

    2015-01-01

    Preventing the off-site effects of soil erosion is an essential part of good catchment management. Most efforts are in the form of on-site soil and water conservation measures. However, sediment trapping can be an alternative (additional) measure to prevent the negative off-site effects of soil

  4. Biodegradation of dispersed marine fuel oil in sediment under engineered pre-spill application strategy

    International Nuclear Information System (INIS)

    Hua, J.

    2006-01-01

    Biodegradation of marine fuel oil was studied by monitoring changes in residual oil and populations of microorganisms in marine sediments. Biodegradation rates for dispersant and soap water were 2.09 and 2.27 g/kg per day, respectively, under pre-application strategy, suggesting that the strategy may promote MFO dispersion and provide with sufficient source of food. The effect of temperature on the effectiveness of pre-application strategy is particularly obvious for the growth of fungi and Pseudomonas maltophilia. The effect of pre-application of soap water on the tolerance of aerobic bacteria, Escherichia coli, and P. maltophilia, was gradually diminished within 25-33 days. (author)

  5. Lake Champlain 10 x 20 NTMS area New York, Vermont, and New Hampshire: data report (abbreviated). National Uranium Resource Evaluation program, hydrogeochemical and stream sediment reconnaissance

    International Nuclear Information System (INIS)

    Cook, J.R.

    1981-03-01

    This abbreviated data report presents results of ground water and stream sediment reconnaissance in the National Topographic Map Series (NTMS) Lake Champlain 1 0 x 2 0 quadrangle. Surface sediment samples were collected at 1196 sites. Ground-water samples were collected at 619 sites. Neutron activation analysis (NAA) results are given for uranium and 16 other elements in sediments, for uranium and 8 other elements in ground water, and for uranium and 9 other elements in surface water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Data from ground-water sites include (1) water chemistry measurements (pH, conductivity, and alkalinity), (2) physical measurements where applicable (water temperature, well description, etc.), and (3) elemental analyses (U, Al, Br, Cl, Dy, F, Mn, Na, and V). Data from sediment sites include (1) stream water chemistry measurements (pH, conductivity, and alkalinity), and (2) elemental analyses for sediment samples (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Sample site descriptors (stream characteristics, vegetation, etc.) are also tabulated. A real distribution maps, histograms, and cumulative frequency plots for most elements and for U/Th and U/Hf ratios are included. Key data from stream water sites include (1) water quality measurements (pH, conductivity, and alkalinity) and (2) elemental analyses (U, Al, Br, Cl, Dy, F, Mg, Mg, Na, and V). Uranium concentrations in the sediments range from 0.30 to 43.40 ppM with a mean of 3.03 ppM. A cluster of high log (U/Th+Hf) ratios appear in the southeastern portion of the quadrangle. The U x 1000/conductivity ratio in surface water is high in this same area

  6. Estimating sedimentation rates and sources in a partially urbanized catchment using caesium-137

    Science.gov (United States)

    Ormerod, L. M.

    1998-06-01

    While there has been increased interest in determining sedimentation rates and sources in agricultural and forested catchments in recent years, there have been few studies dealing with urbanized catchments. A study of sedimentation rates and sources within channel and floodplain deposits of a partially urbanized catchment has been undertaken using the 137Cs technique. Results for sedimentation rates showed no particular downstream pattern. This may be partially explained by underestimation of sedimentation rates at some sites by failure to sample the full 137Cs profile, floodplain erosion and deliberate removal of sediment. Evidence of lateral increases in net sedimentation rates with distance from the channel may be explained by increased floodplain erosion at sites closer to the channel and floodplain formation by lateral deposition. Potential sediment sources for the catchment were considered to be forest topsoil, subsurface material and sediments derived from urban areas, which were found to be predominantly subsurface material. Tracing techniques showed an increase in subsurface material for downstream sites, confirming expectations that subsurface material would increase in the downstream direction in response to the direct and indirect effects of urbanization.

  7. Biogeochemical malfunctioning in sediments beneath a deep-water fish farm.

    Science.gov (United States)

    Valdemarsen, Thomas; Bannister, Raymond J; Hansen, Pia K; Holmer, Marianne; Ervik, Arne

    2012-11-01

    We investigated the environmental impact of a deep water fish farm (190 m). Despite deep water and low water currents, sediments underneath the farm were heavily enriched with organic matter, resulting in stimulated biogeochemical cycling. During the first 7 months of the production cycle benthic fluxes were stimulated >29 times for CO(2) and O(2) and >2000 times for NH(4)(+), when compared to the reference site. During the final 11 months, however, benthic fluxes decreased despite increasing sedimentation. Investigations of microbial mineralization revealed that the sediment metabolic capacity was exceeded, which resulted in inhibited microbial mineralization due to negative feed-backs from accumulation of various solutes in pore water. Conclusions are that (1) deep water sediments at 8 °C can metabolize fish farm waste corresponding to 407 and 29 mmol m(-2) d(-1) POC and TN, respectively, and (2) siting fish farms at deep water sites is not a universal solution for reducing benthic impacts. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Precipitation, streamflow, suspended-sediment, and water-quality data for the U.S. Army Garrison Fort Carson and Piñon Canyon Maneuver Site, Colorado, 1966–2015

    Science.gov (United States)

    Arnold, L.R.

    2017-08-03

    The U.S. Army Garrison Fort Carson (AGFC) and the Piñon Canyon Maneuver Site (PCMS) are facilities operated by the U.S. Department of the Army in southern Colorado. The U.S. Geological Survey, in cooperation with the U.S. Department of the Army, established a hydrologic and water-quality data-collection network at the AGFC in June 1978 and at the PCMS in October 1982. The data-collection networks are designed to assess the quantity and quality of water resources and monitor the effects of military training activities on streamflow and water quality. Two preexisting U.S. Geological Survey streamgages at the PCMS were incorporated into the data-collection network at the time it was established, providing periods of record that begin as early as 1966. This report presents and summarizes precipitation, streamflow, suspended-sediment, and water-quality data from 34 U.S. Geological Survey sites on or near the AGFC and the PCMS for the period of record at each site. (Streamflow data are presented as discharge in cubic feet per second.)At AGFC, daily sum precipitation ranged from 0 to 11.85 inches, daily mean discharge ranged from 0 to 836 cubic feet per second, and daily mean suspended-sediment discharge ranged from 0 to 39,900 tons per day. With the exception of total (unfiltered) mercury and filtered sulfate at two sites and filtered manganese at three sites, 95th percentile trace element concentrations and median total (unfiltered) metal concentrations were less than regulatory numeric standards for all samples. However, individual water-quality results occasionally exceeded respective regulatory numeric standards.At the PCMS, daily sum precipitation ranged from 0 to 4.59 inches, daily mean discharge ranged from 0 to 4,190 cubic feet per second, and daily mean suspended-sediment discharge ranged from 0 to 21,100 tons per day. Water-quality results, 95th percentile trace element concentrations, and median total (unfiltered) metal concentrations were less than

  9. 47 CFR 22.939 - Site availability requirements for applications competing with cellular renewal applications.

    Science.gov (United States)

    2010-10-01

    ... competing with cellular renewal applications. 22.939 Section 22.939 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Cellular Radiotelephone Service § 22.939 Site availability requirements for applications competing with cellular renewal applications. In...

  10. Forsmark site investigation. Investigation of marine and lacustrine sediment in lakes. Field data 2003

    Energy Technology Data Exchange (ETDEWEB)

    Hedenstroem, Anna [SGU, Uppsala (Sweden)

    2003-04-01

    The aim of this activity is to describe the aerial and stratigraphical distribution of marine and lacustrine sediment i.e. sediment overlaying the glacial till and/or bedrock surface, in lakes in the Forsmark area. The investigation is carried out within areas where mapping of unconsolidated Quaternary deposits is presently carried out. Since small and shallow lakes cover a large part of the region, this work will give important information on the distribution and stratigraphy of sedimentary deposits not included in the regular mapping of unconsolidated Quaternary deposits within the site investigation programme. Samples were also collected for laboratory analyses of grain size distribution, mineralogical composition as well as the total content of C, N and S and calcium carbonate. The analyses will be carried out on selected samples of representative sedimentary units in order to characterise the chemical and physical properties of the unconsolidated deposits. The analytical data will be useful for the hydrogeological modelling and for models of the Quaternary evolution of the area. The mineralogical analyses of clay may provide information on the origin of the clay particles. One stratigraphic sequence from Lake Eckarfjaerden will be stored for later analyses, e.g. pollen analysis. This report includes field data from spring 2003. Together, the field data and the forthcoming results from the laboratory analyses will form the basis for construction of stratigraphical profiles to be presented in a following report in the fall 2003.

  11. Forsmark site investigation. Investigation of marine and lacustrine sediment in lakes. Field data 2003

    International Nuclear Information System (INIS)

    Hedenstroem, Anna

    2003-04-01

    The aim of this activity is to describe the aerial and stratigraphical distribution of marine and lacustrine sediment i.e. sediment overlaying the glacial till and/or bedrock surface, in lakes in the Forsmark area. The investigation is carried out within areas where mapping of unconsolidated Quaternary deposits is presently carried out. Since small and shallow lakes cover a large part of the region, this work will give important information on the distribution and stratigraphy of sedimentary deposits not included in the regular mapping of unconsolidated Quaternary deposits within the site investigation programme. Samples were also collected for laboratory analyses of grain size distribution, mineralogical composition as well as the total content of C, N and S and calcium carbonate. The analyses will be carried out on selected samples of representative sedimentary units in order to characterise the chemical and physical properties of the unconsolidated deposits. The analytical data will be useful for the hydrogeological modelling and for models of the Quaternary evolution of the area. The mineralogical analyses of clay may provide information on the origin of the clay particles. One stratigraphic sequence from Lake Eckarfjaerden will be stored for later analyses, e.g. pollen analysis. This report includes field data from spring 2003. Together, the field data and the forthcoming results from the laboratory analyses will form the basis for construction of stratigraphical profiles to be presented in a following report in the fall 2003

  12. Effects-based spatial assessment of contaminated estuarine sediments from Bear Creek, Baltimore Harbor, MD, USA.

    Science.gov (United States)

    Hartzell, Sharon E; Unger, Michael A; McGee, Beth L; Wilson, Sacoby M; Yonkos, Lance T

    2017-10-01

    Estuarine sediments in regions with prolonged histories of industrial activity are often laden to significant depths with complex contaminant mixtures, including trace metals and persistent organic pollutants. Given the complexity of assessing risks from multi-contaminant exposures, the direct measurement of impacts to biological receptors is central to characterizing contaminated sediment sites. Though biological consequences are less commonly assessed at depth, laboratory-based toxicity testing of subsurface sediments can be used to delineate the scope of contamination at impacted sites. The extent and depth of sediment toxicity in Bear Creek, near Baltimore, Maryland, USA, was delineated using 10-day acute toxicity tests with the estuarine amphipod Leptocheirus plumulosus, and chemical analysis of trace metals and persistent organic pollutants. A gradient of toxicity was demonstrated in surface sediments with 21 of 22 tested sites differing significantly from controls. Effects were most pronounced (100% lethality) at sites proximate to a historic industrial complex. Sediments from eight of nine core samples to depths of 80 cm were particularly impacted (i.e., caused significant lethality to L. plumulosus) even in locations overlain with relatively non-toxic surface sediments, supporting a conclusion that toxicity observed at the surface (top 2 cm) does not adequately predict toxicity at depth. In seven of nine sites, toxicity of surface sediments differed from toxicity at levels beneath by 28 to 69%, in five instances underestimating toxicity (28 to 69%), and in two instances overestimating toxicity (44 to 56%). Multiple contaminants exceeded sediment quality guidelines and correlated positively with toxic responses within surface sediments (e.g., chromium, nickel, polycyclic aromatic hydrocarbon (PAH), total petroleum hydrocarbon). Use of an antibody-based PAH biosensor revealed that porewater PAH concentrations also increased with depth at most sites. This

  13. Legacy sediment storage in New England river valleys: anthropogenic processes in a postglacial landscape

    Science.gov (United States)

    Snyder, N. P.; Johnson, K. M.; Waltner, M.; Hopkins, A. J.; Dow, S.; Ames, E.; Merritts, D. J.; Walter, R. C.; Rahnis, M. A.

    2016-12-01

    Walter and Merritts (2008, and subsequent papers) show that legacy sediment associated with deposition in millponds is a common feature in river valleys of the Mid-Atlantic Piedmont region, with 1-5 m of fine sand and silt overlying Holocene soil and Pleistocene periglacial deposits. For this project, we seek to test the hypothesis that these field relationships are seen in New England, a formerly glaciated region with similar history and intensity of forest clearing and milldam construction during the 17-19th centuries. We study three watersheds, using field observations of bank stratigraphy, radiocarbon dating, and mapping of terraces and floodplains using lidar digital elevation models and other GIS datasets. The 68 km2 South River watershed in western Massachusetts exhibits the most extensive evidence for legacy sediment storage. We visited 17 historic dam sites in the watershed and found field evidence for fine sand and silt legacy sediment storage at 14, up to 2.2 m thick. In the 558 km2 Sheepscot River watershed in coastal Maine, we visited 12 historic dam sites, and found likely legacy sediment at six, up to 2.3 m thick. In the 171 km2 upper Charles River watershed in eastern Massachusetts, we investigated 14 dam sites, and found legacy sediment at two, up to 1.8 m thick. Stratigraphically, we identified the base of legacy sediment from a change in grain size to gravel at most sites, or to Pleistocene marine clay at some Sheepscot River sites. In the Sheepscot River, we observed cut timbers underlying historic sediment at several locations, likely associated with sawmill activities. Only at the Charles River were we able to radiocarbon date the underlying gravel (1281-1391 calibrated CE). At no site did we find a buried Holocene soil, in contrast to the field relations commonly observed in the Mid-Atlantic region. This may indicate that the New England sites have eroded to the pre-historic river bed, not floodplain surfaces. We attribute the variation in

  14. Hanford Site air operating permit application

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    The Clean Air Act Amendments of 1990, which amended the Federal Clean Air Act of 1977, required that the US Environmental Protection Agency develop a national Air Operating Permit Program, which in turn would require each state to develop an Air Operating Permit Program to identify all sources of ``regulated`` pollutants. Regulated pollutants include ``criteria`` pollutants (oxides of nitrogen, sulfur oxides, total suspended particulates, carbon monoxide, particulate matter greater than 10 micron, lead) plus 189 other ``Hazardous`` Air Pollutants. The Hanford Site, owned by the US Government and operated by the US Department of Energy, Richland Operations Office, is located in southcentral Washington State and covers 560 square miles of semi-arid shrub and grasslands located just north of the confluence of the Snake and Yakima Rivers with the Columbia River. This land, with restricted public access, provides a buffer for the smaller areas historically used for the production of nuclear materials, waste storage, and waste disposal. About 6 percent of the land area has been disturbed and is actively used. The Hanford Site Air Operating Permit Application consists of more than 1,100 sources and in excess of 300 emission points. Before January 1995, the maintenance and operations contractor and the environmental restoration contractor for the US Department of Energy completed an air emission inventory on the Hanford Site. The inventory has been entered into a database so that the sources and emission points can be tracked and updated information readily can be retrieved. The Hanford Site Air Operating Permit Application contains information current as of April 19, 1995.

  15. Hanford Site air operating permit application

    International Nuclear Information System (INIS)

    1995-05-01

    The Clean Air Act Amendments of 1990, which amended the Federal Clean Air Act of 1977, required that the US Environmental Protection Agency develop a national Air Operating Permit Program, which in turn would require each state to develop an Air Operating Permit Program to identify all sources of ''regulated'' pollutants. Regulated pollutants include ''criteria'' pollutants (oxides of nitrogen, sulfur oxides, total suspended particulates, carbon monoxide, particulate matter greater than 10 micron, lead) plus 189 other ''Hazardous'' Air Pollutants. The Hanford Site, owned by the US Government and operated by the US Department of Energy, Richland Operations Office, is located in southcentral Washington State and covers 560 square miles of semi-arid shrub and grasslands located just north of the confluence of the Snake and Yakima Rivers with the Columbia River. This land, with restricted public access, provides a buffer for the smaller areas historically used for the production of nuclear materials, waste storage, and waste disposal. About 6 percent of the land area has been disturbed and is actively used. The Hanford Site Air Operating Permit Application consists of more than 1,100 sources and in excess of 300 emission points. Before January 1995, the maintenance and operations contractor and the environmental restoration contractor for the US Department of Energy completed an air emission inventory on the Hanford Site. The inventory has been entered into a database so that the sources and emission points can be tracked and updated information readily can be retrieved. The Hanford Site Air Operating Permit Application contains information current as of April 19, 1995

  16. Coastal sediment elevation change following anthropogenic mangrove clearing

    Science.gov (United States)

    Hayden, Heather L.; Granek, Elise F.

    2015-11-01

    Coastal mangrove forests along tropical shorelines serve as an important interface between land and sea. They provide a physical buffer protecting the coastline from erosion and act as sediment "traps" catching terrestrial sediment, thus preventing smothering of subtidal coral reefs. Coastal development that removes mangrove habitat may impact adjacent nearshore coral reefs through sedimentation and nutrient loading. We examined differences in sediment elevation change between patches of open-coast intact and anthropogenically cleared red mangroves (Rhizophora mangle) on the east side of Turneffe Atoll, Belize, to quantify changes following mangrove clearing. Samples were collected over a 24 month period at five study sites, each containing paired intact (+mangrove) and cleared (-mangrove) plots. Five sediment elevation pins were deployed in each plot: behind areas cleared of mangroves (-mangrove) and behind adjacent intact mangroves (+mangrove). Sediment elevation increased at intact mangrove sites (M = +3.83 mm, SE = 0.95) whereas cleared mangrove areas suffered elevation loss (M = -7.30 mm, SE = 3.38). Mangroves inshore of partial or continuous gaps in the adjacent fringing reefs had higher rates of elevation loss (M = -15.05 mm) than mangroves inshore of continuous fringing reefs (M = -1.90 mm). Our findings provide information on potential effects of mangrove clearing and the role of offshore habitat characteristics on coastal sediment trapping and maintenance of sediment elevation by mangroves. With implications for coastline capacity to adjust to sea level rise, these findings are relevant to management of coastal fringing mangrove forests across the Caribbean.

  17. Resolving and modelling trace metal partitioning in a freshwater sediment

    International Nuclear Information System (INIS)

    Devallois, V.; Boyer, P.; Coulomb, B.; Boudenne, J. L.

    2009-01-01

    Elevated concentrations of trace metals in sediments pose toxicological risks to biota and may impair water quality. the sediment-water interface is the site where gradients in physical, chemical and biological properties are the greatest. Both chemical and microbiological transformation processes are responsible for cycling elements between water and sediments. (Author)

  18. Technology application analyses at five Department of Energy Sites

    International Nuclear Information System (INIS)

    1995-05-01

    The Hazardous Waste Remedial Actions Program (HAZWRAP), a division of Lockheed Martin Energy Systems, Inc., managing contractor for the Department of Energy (DOE) facilities in Oak Ridge, Tennessee, was tasked by the United States Air Force (USAF) through an Interagency Agreement between DOE and the USAF, to provide five Technology Application Analysis Reports to the USAF. These reports were to provide information about DOE sites that have volatile organic compounds contaminating soil or ground water and how the sites have been remediated. The sites were using either a pump-and-treat technology or an alternative to pump-and-treat. The USAF was looking at the DOE sites for lessons learned that could be applied to Department of Defense (DoD) problems in an effort to communicate throughout the government system. The five reports were part of a larger project undertaken by the USAF to look at over 30 sites. Many of the sites were DoD sites, but some were in the private sector. The five DOE projects selected to be reviewed came from three sites: the Savannah River Site (SRS), the Kansas City Site, and Lawrence Livermore National Laboratory (LLNL). SRS and LLNL provided two projects each. Both provided a standard pump-and-treat application as well as an innovative technology that is an alternative to pump-and-treat. The five reports on these sites have previously been published separately. This volume combines them to give the reader an overview of the whole project

  19. Aromatic hydrocarbon concentrations in sediments of Placentia Bay, Newfoundland

    International Nuclear Information System (INIS)

    Kiceniuk, J.W.

    1992-01-01

    A study was conducted to examine the potential for contamination of recent sediments with polycyclic aromatic hydrocarbons due to tanker and refinery activity in Placentia Bay, Newfoundland, an area without large local anthropogenic sources of aromatics. Sediment samples were taken from the vicinity of the Come By Chance refinery, Woody Island, Wild Cove, and Port Royal Arm, all in the north end of the bay. The samples were extracted by two methods, dichloromethane extraction of dried sediment for determination of total aromatic hydrocarbon content and hexane extraction of wet sediment for estimation of the bioavailability of hydrocarbons and determination of more volatile compounds. Class analysis of aromatic hydrocarbons was conducted on a NH 2 column with detection at 255 nm. Total concentrations of di-tricyclic aromatics were highest at the Woody Island site (0.6 μg/g). The sediments from the Come By Chance site, Wild Cove, and Port Royal Arm sediments contained 0.3, 0.1, and 0.2 μg/g respectively. The hexane extracts from Come By Chance were lowest in di-tricyclic aromatics (0.007 μg/g), with the other sites being equal in concentration (0.01 μg/g). It is evident from the study that aromatic hydrocarbon concentrations in Placentia Bay are elevated in some parts of the bay in the absence of local combustion sources, and that the most likely source is petroleum. 12 refs., 5 figs., 2 tabs

  20. Can behavioural responses of Lumbriculus variegatus (Oligochaeta) assess sediment toxicity? A case study with sediments exposed to acid mine drainage

    International Nuclear Information System (INIS)

    Sardo, A.M.; Soares, A.M.V.M.

    2010-01-01

    The Sao Domingos mine (Portugal) is, potentially, a good site for ecotoxicological studies, due to a pH and metal gradient of acid mine drainage. In this study, the toxicity of several mine sediments was evaluated using the aquatic oligochaete Lumbriculus variegatus as a test organism. Our hypothesis was that exposure to contaminated sediments would cause behavioural early warning responses in L. variegatus. Five sites, with pH ranging from 2.5 to 6.5, and with associated metals, were investigated. The results showed poor sediment quality in most of the collected sediments and Fe, S and As were the dominant elements in the samples. High mortalities were observed, ranging from 32.6 to 100%, indicating severe contamination. The collected sediments did not support good L. variegatus growth and significantly changed its behaviour. Early warning responses consisted of decreased locomotion and decreased peristaltic movements. A behaviour inhibition will affect the ecosystem balance by limiting the organisms' ability to avoid capture, which leads to a higher risk of predation. - Behavioural responses of the aquatic oligochaeta Lumbriculus variegatus may be used to detect early warning responses.

  1. Mercury contaminated sediment sites—An evaluation of remedial options

    Energy Technology Data Exchange (ETDEWEB)

    Randall, Paul M., E-mail: randall.paul@epa.gov [U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, 26 West Martin Luther King Drive, Cincinnati, OH 45268 (United States); Chattopadhyay, Sandip, E-mail: Sandip.Chattopadhyay@tetratech.com [Tetra Tech, Inc., 250 West Court Street, Suite 200W, Cincinnati, OH 45202 (United States)

    2013-08-15

    Mercury (Hg) is a naturally-occurring element that is ubiquitous in the aquatic environment. Though efforts have been made in recent years to decrease Hg emissions, historically-emitted Hg can be retained in the sediments of aquatic bodies where they may be slowly converted to methylmercury (MeHg). Consequently, Hg in historically-contaminated sediments can result in high levels of significant exposure for aquatic species, wildlife and human populations consuming fish. Even if source control of contaminated wastewater is achievable, it may take a very long time, perhaps decades, for Hg-contaminated aquatic systems to reach relatively safe Hg levels in both water and surface sediment naturally. It may take even longer if Hg is present at higher concentration levels in deep sediment. Hg contaminated sediment results from previous releases or ongoing contributions from sources that are difficult to identify. Due to human activities or physical, chemical, or biological processes (e.g. hydrodynamic flows, bioturbation, molecular diffusion, and chemical transformation), the buried Hg can be remobilized into the overlying water. Hg speciation in the water column and sediments critically affect the reactivity (i.e. conversion of inorganic Hg(II) to MeHg), transport, and its exposure to living organisms. Also, geochemical conditions affect the activity of methylating bacteria and its availability for methylation. This review paper discusses remedial considerations (e.g. key chemical factors in fate and transport of Hg, source characterization and control, environmental management procedures, remediation options, modeling tools) and includes practical case studies for cleaning up Hg-contaminated sediment sites. -- Highlights: ► Managing mercury-contaminated sediment sites are challenging to remediate. ► Remediation technologies are making a difference in managing these sites. ► Partitioning plays a dominant role in the distribution of mercury species. ► Mathematical

  2. MORPHOLOGY OF METHANE HYDRATE HOST SEDIMENTS

    International Nuclear Information System (INIS)

    JONES, K.W.; FENG, H.; TOMOV, S.; WINTER, W.J.; EATON, M.; MAHAJAN, D.

    2004-01-01

    Results from simulated experiments in several laboratories show that host sediments influence hydrate formation in accord with known heterogeneity of host sediments at sites of gas hydrate occurrence (1). For example, in Mackenzie Delta, NWT Canada (Mallik 2L-38 well), coarser-grained units (pore-filling model) are found whereas in the Gulf of Mexico, the found hydrate samples do not appear to be lithologically controlled. We have initiated a systematic study of sediments, initially focusing on samples from various depths at a specific site, to establish a correlation with hydrate occurrence (or variations thereof) to establish differences in their microstructure, porosity, and other associated properties. The synchrotron computed microtomography (CMT) set-up at the X-27A tomography beam line at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory was used as a tool to study sediments from Blake Ridge at three sub bottom depths of 0.2, 50, and 667 meters. Results from the tomographic analysis of the deepest sample (667 m) are presented here to illustrate how tomography can be used to obtain new insights into the structures of methane hydrate host sediments. The investigation shows the internal grain/pore space resolution in the microstructure and a 3-D visualization of the connecting pathways obtained following data segmentation into pore space and grains within the sediment sample. The analysis gives the sample porosity, specific surface area, mean particle size, and tortuosity, as well. An earlier report on the experimental program has been given by Mahajan et al. (2)

  3. Hanford Site Solid Waste Landfill permit application. Revision 1

    International Nuclear Information System (INIS)

    1993-01-01

    Both nonhazardous and nonradioactive sanitary solid waste are generated at the Hanford Site. This permit application describes the manner in which the Solid Waste Landfill will be operated. A description is provided of the landfill, including applicable locational, general facility, and landfilling standards. The characteristics and quantity of the waste disposed of are discussed. The regional and site geology and hydrology and the groundwater and vadose zone quality beneath the landfill are reviewed. A plan is included of operation, closure, and postclosure. This report addresses the operational cover, environmental controls, personnel requirements, inspections, recordkeeping, reporting, and site security. The integration of closure and postclosure activities between the Solid Waste Landfill and adjacent Nonradioactive Dangerous Waste Landfill is discussed

  4. Overview of the U.S. EPA/SERDP/ESTCP: Laboratory, Field, and Analytical Procedures for Using Passive Sampling in the Evaluation of Contaminated Sediments: User’s Manual.

    Science.gov (United States)

    Passive sampling is used for applications at contaminated sediment sites including performing assessments of contaminant bioavailability (i.e., freely dissolved concentration (Cfree)), conducting remedial investigations and feasibility studies, and assessing the potential for con...

  5. Guideline for environmental site investigations in Manitoba : June 1998

    International Nuclear Information System (INIS)

    1998-06-01

    The procedures for the investigation and characterization of contaminated sites in Manitoba are described in an effort to provide a baseline for developing applicable risk-based remedial action and management plans. This document presents information regarding the methods and protocols for sites where the quality of groundwater, surface water, sediments or soil may have been affected by pollutants as a result of past or present usage of the site. The 1998 document focuses on petroleum impacted sites and also includes the requirements for the investigation of sites potentially impacted by other pollutants. It is based on the principles established by the Canadian Council of Ministers of the Environment for the management of sites in Canada and the requirements of the Manitoba Contaminated Sites Remediation and Consequential Amendments Act. Manitoba's petroleum storage program and the hazardous waste management program, including the disposal or treatment of contaminated soils are also summarized

  6. Solid/liquid partition coefficients (Kd) for selected soils and sediments at Forsmark and Laxemar-Simpevarp

    Energy Technology Data Exchange (ETDEWEB)

    Sheppard, Steve; Long, Jeff; Sanipelli, Barb [ECOMatters Inc., Pinawa (Canada); Sohlenius, Gustav [Geological Survey of Sweden (SGU), Uppsala (Sweden)

    2009-03-15

    Soil and sediment solid/liquid partition coefficients (Kd) are used to indicate the relative mobility of radionuclides and elements of concern from nuclear fuel waste, as well as from other sources. The Kd data are inherently extremely variable, but also vary systematically with key environmental attributes. For soil Kd, the key variables are pH, clay content and organic carbon content. For sediment Kd, water type (freshwater versus marine) and sediment type (benthic versus suspended) are important. This report summarized Kd data for soils and sediments computed from indigenous stable element concentrations measured at the Forsmark and Laxemar-Simpevarp sites. These were then compared to several literature sources of Kd data for Ce, Cl, Co, Cr, Cs, Fe, Ho, I, La, Mn, Mo, Nb, Nd, Ni, Np, Pa, Pb, Pu, Ra, Sb, Se, Sm, Sn, Sr, Tc, Th, Tm, U and Yb. The Kd data computed from indigenous stable element concentrations may be especially relevant for assessment of long-lived radionuclides from deep disposal of waste, because the long time frame for the potential releases is more consistent with the steady state measured using indigenous stable elements. For almost every one of these elements in soils, a statistically meaningful regression equation was developed to allow estimation of Kd for any soil given a modest amount of information about the soil. Nonetheless, the median residual geometric standard deviation (GSD) was 4.3-fold, implying confidence bounds of about 18-fold above and below the best estimate Kd. For sediment, the values are categorised simply by water type and sediment type. The median GSD for sediment Kd as measured at the Forsmark and Laxemar-Simpevarp sites was 2.5-fold, but the median GSD among literature values was as high as 8.6-fold. Clearly, there remains considerable uncertainty in Kd values, and it is important to account for this in assessment applications

  7. Solid/liquid partition coefficients (Kd) for selected soils and sediments at Forsmark and Laxemar-Simpevarp

    International Nuclear Information System (INIS)

    Sheppard, Steve; Long, Jeff; Sanipelli, Barb; Sohlenius, Gustav

    2009-03-01

    Soil and sediment solid/liquid partition coefficients (Kd) are used to indicate the relative mobility of radionuclides and elements of concern from nuclear fuel waste, as well as from other sources. The Kd data are inherently extremely variable, but also vary systematically with key environmental attributes. For soil Kd, the key variables are pH, clay content and organic carbon content. For sediment Kd, water type (freshwater versus marine) and sediment type (benthic versus suspended) are important. This report summarized Kd data for soils and sediments computed from indigenous stable element concentrations measured at the Forsmark and Laxemar-Simpevarp sites. These were then compared to several literature sources of Kd data for Ce, Cl, Co, Cr, Cs, Fe, Ho, I, La, Mn, Mo, Nb, Nd, Ni, Np, Pa, Pb, Pu, Ra, Sb, Se, Sm, Sn, Sr, Tc, Th, Tm, U and Yb. The Kd data computed from indigenous stable element concentrations may be especially relevant for assessment of long-lived radionuclides from deep disposal of waste, because the long time frame for the potential releases is more consistent with the steady state measured using indigenous stable elements. For almost every one of these elements in soils, a statistically meaningful regression equation was developed to allow estimation of Kd for any soil given a modest amount of information about the soil. Nonetheless, the median residual geometric standard deviation (GSD) was 4.3-fold, implying confidence bounds of about 18-fold above and below the best estimate Kd. For sediment, the values are categorised simply by water type and sediment type. The median GSD for sediment Kd as measured at the Forsmark and Laxemar-Simpevarp sites was 2.5-fold, but the median GSD among literature values was as high as 8.6-fold. Clearly, there remains considerable uncertainty in Kd values, and it is important to account for this in assessment applications

  8. Microbial reduction of uranium(VI) in sediments of different lithologies collected from Sellafield

    International Nuclear Information System (INIS)

    Newsome, Laura; Morris, Katherine; Trivedi, Divyesh; Atherton, Nick; Lloyd, Jonathan R.

    2014-01-01

    Highlights: • U(VI) (aq) mobility can be controlled by stimulating biogeochemical interactions. • Indigenous microbes in varied sediments reduced U(VI) to insoluble U(IV). • Sediment cell numbers and amount of bioavailable Fe(III) could limit this process. - Abstract: The presence of uranium in groundwater at nuclear sites can be controlled by microbial processes. Here we describe the results from stimulating microbial reduction of U(VI) in sediment samples obtained from a nuclear-licensed site in the UK. A variety of different lithology sediments were selected to represent the heterogeneity of the subsurface at a site underlain by glacial outwash deposits and sandstone. The natural sediment microbial communities were stimulated via the addition of an acetate/lactate electron donor mix and were monitored for changes in geochemistry and molecular ecology. Most sediments facilitated the removal of 12 ppm U(VI) during the onset of Fe(III)-reducing conditions; this was reflected by an increase in the proportion of known Fe(III)- and U(VI)-reducing species. However U(VI) remained in solution in two sediments and Fe(III)-reducing conditions did not develop. Sequential extractions, addition of an Fe(III)-enrichment culture and most probable number enumerations revealed that a lack of bioavailable iron or low cell numbers of Fe(III)-reducing bacteria may be responsible. These results highlight the potential for stimulation of microbial U(VI)-reduction to be used as a bioremediation strategy at UK nuclear sites, and they emphasise the importance of both site-specific and borehole-specific investigations to be completed prior to implementation

  9. Testing single-grain quartz OSL methods using sediment samples with independent age control from the Bordes-Fitte rockshelter (Roches d'Abilly site, Central France)

    DEFF Research Database (Denmark)

    Thomsen, Kristina Jørkov; Murray, Andrew Sean; Buylaert, Jan-Pieter

    2016-01-01

    We present quartz single-grain dose distributions for four well-bleached and unmixed sediment samples with independent age control (22–48 ka), from the archaeologically important Bordes-Fitte rockshelter at Roches d'Abilly, France. This site has previously been dated using 14C AMS dating and stan...

  10. On site clean up with a hazardous waste incinerator

    International Nuclear Information System (INIS)

    Cross, F.L. Jr.; Tessitore, J.L.

    1987-01-01

    The Army Corps of Engineers and the EPA have determined that on-site incineration for the detoxification of soils, sediments, and sludges is a viable, safe, and economic alternative. This paper discusses an approach to on-site incineration as a method of detoxification of soils/sediments contaminated with organic hazardous wastes. Specifically, this paper describes the procedures used to evaluate on-site incineration at a large Superfund site with extensive PCB contaminated soils and sediments. The paper includes the following: (1) a discussion of site waste quantities and properties, (2) a selection of an incineration technology with a resulting concept and design, (3) a discussion of incinerator permitting requirements, (4) discussion and rationale for an incinerator sub-scale testing approach, and (5) analysis of on-site incineration cost

  11. Ecotoxicological evaluation of sediments applied to environmental forensic investigation

    Directory of Open Access Journals (Sweden)

    R. H. Alves

    Full Text Available Abstract The present study aimed to evaluate the potential for using toxicity assays with sediment samples for the detection of water pollution caused by the discharge of tannery effluents into water bodies and its application to environmental forensic investigation. The study included ecotoxicological evaluation of sediments, survey of benthic organisms in the field, as well as chromium, cadmium and lead dosage which provided data for a sediment quality triad evaluation. The sediment samples showed acute and chronic toxicity to the bioindicators, low biodiversity of benthic macrofauna and high chromium concentration, reaching up to 4365 mg.Kg–1. A close relationship was observed between the separate results of ecotoxicological sediment evaluation and the sediment quality triad. The sediment ecotoxicological assessment proved to be applicable to tracking sources of contamination related to tanneries and similar activities in environmental forensics.

  12. Effects of Feeding Strategy, Sediment Characteristics, and Chemical Properties on Polychlorinated Biphenyl and Polybrominated Diphenyl Ether Bioaccumulation from Marine Sediments in Two Invertebrates.

    Science.gov (United States)

    Frouin, H; Jackman, P; Dangerfield, N D; Ross, P S

    2017-08-01

    Shellfish and sediment invertebrates have been widely used to assess pollution trends over space and time in coastal environments around the world. However, few studies have compared the bioaccumulation potential of different test species over a range of sediment-contaminant concentrations and profiles. The bioavailability of sediment-related contaminants was evaluated using sediments collected from sites (n = 12) throughout the Salish Sea, British Columbia, Canada. Two benthic marine invertebrates-the Baltic clam Macoma balthica and the polychaete worm Neanthes arenaceodentata-were exposed for 28 days in a controlled environment to these field-collected coastal sediments. The congener-specific uptake of legacy polychlorinated biphenyls (PCBs) and emergent polybrominated diphenyl ethers (PBDEs) was determined using high-resolution gas chromatography/mass spectrometry in sediments and in invertebrates after the experimental exposure. The polychaete Neanthes accumulated lower concentrations of PCBs but higher concentrations of PBDEs. The present study indicates that differences in bioaccumulation between these two invertebrates shape the accumulation of PCB and PBDE congeners, reflect differences in feeding strategies, and reveal the physicochemical properties of the contaminants and sediment properties. Because biota-sediment accumulation factor values are often calculated for environmental monitoring or site-specific impact assessments, our results provide insight into potentially confounding factors and the need for caution when selecting indicator species for coastal marine pollution.

  13. When Theory Meets Data: Comparing Model Predictions Of Hillslope Sediment Size With Field Measurements.

    Science.gov (United States)

    Mahmoudi, M.; Sklar, L. S.; Leclere, S.; Davis, J. D.; Stine, A.

    2017-12-01

    The size distributions of sediment produced on hillslopes and supplied to river channels influence a wide range of fluvial processes, from bedrock river incision to the creation of aquatic habitats. However, the factors that control hillslope sediment size are poorly understood, limiting our ability to predict sediment size and model the evolution of sediment size distributions across landscapes. Recently separate field and theoretical investigations have begun to address this knowledge gap. Here we compare the predictions of several emerging modeling approaches to landscapes where high quality field data are available. Our goals are to explore the sensitivity and applicability of the theoretical models in each field context, and ultimately to provide a foundation for incorporating hillslope sediment size into models of landscape evolution. The field data include published measurements of hillslope sediment size from the Kohala peninsula on the island of Hawaii and tributaries to the Feather River in the northern Sierra Nevada mountains of California, and an unpublished data set from the Inyo Creek catchment of the southern Sierra Nevada. These data are compared to predictions adapted from recently published modeling approaches that include elements of topography, geology, structure, climate and erosion rate. Predictive models for each site are built in ArcGIS using field condition datasets: DEM topography (slope, aspect, curvature), bedrock geology (lithology, mineralogy), structure (fault location, fracture density), climate data (mean annual precipitation and temperature), and estimates of erosion rates. Preliminary analysis suggests that models may be finely tuned to the calibration sites, particularly when field conditions most closely satisfy model assumptions, leading to unrealistic predictions from extrapolation. We suggest a path forward for developing a computationally tractable method for incorporating spatial variation in production of hillslope

  14. Characterization of sediment in a leaching trench RCRA (Resource Conservation and Recovery Act) site

    International Nuclear Information System (INIS)

    Zimmerman, M.G.; Kossik, C.D.

    1988-01-01

    Hazardous materials potentially were disposed of into a pair of leaching trenches from 1975 until Resource Conservation and Recovery Act (RCRA) regulations were imposed in 1985. These leaching trenches now are used for disposal of nonhazardous process water. The typical effluent (approximately 3 million gal/d) consisted of water with trace quantities of laboratory, maintenance, and fuel fabrication process chemicals. The largest constituent in the waste stream was uranium in low concentrations. This paper describes the project used to analyze and characterize the sediments in and below the leaching trenches. Two phases of sediment sampling were performed. The first phase consisted of taking samples between the bottom of the trenches and groundwater to locate contamination in the deep sediments under the trenches. To accomplish this sampling, a series of wells were drilled, and samples were obtained for every five feet in depth. The second phase consisted of samples taken at three depths in a series of positions along each trench. Sampling was completed to determine contamination levels in the shallow sediments and loose material washed into the trenches from the process sewer system. The project results were that no measurable contamination was found in the deep sediments. Measurable contamination from metals, such as chromium and nickel, was found in the shallow sediments. The primary contaminant in the shallow sediments was uranium. The concentration of contaminants decreased rapidly to near-background levels at shallow depths below the bottoms of the trenches

  15. Selected organic compounds and trace elements in streambed sediments and fish tissues, Cook Inlet Basin, Alaska

    Science.gov (United States)

    Frenzel, Steven A.

    2000-01-01

    Organochlorines, semivolatile organic compounds (SVOCs), and trace elements were investigated in streambed sediments and fish tissues at selected sites in the Cook Inlet Basin, Alaska, during 1998. At most sites, SVOCs and organochlorine compounds were either not detected or detected at very low concentrations. Chester Creek at Arctic Boulevard at Anchorage, which was the only site sampled with a significant degree of development in the watershed, had elevated levels of many SVOCs in streambed sediment. Coring of sediments from two ponds on Chester Creek confirmed the presence of elevated concentrations of a variety of organic compounds. Moose Creek, a stream with extensive coal deposits in its watershed, had low concentrations of numerous SVOCs in streambed sediment. Three sites located in national parks or in a national wildlife refuge had no detectable concentrations of SVOCs. Trace elements were analyzed in both streambed sediments and tissues of slimy sculpin. The two media provided similar evidence for elevated concentrations of cadmium, lead, and zinc at Chester Creek. In this study, 'probable effect levels '(PELs) were determined from sediments finer than 0.063 millimeters, where concentrations tend to be greatest. Arsenic and chromium concentrations exceeded the PEL at eight and six sites respectively. Zinc exceeded the PEL at one site. Cadmium and copper concentrations were smaller than the PEL at all sites. Mercury concentrations in streambed sediments from the Deshka River were near the PEL, and selenium concentrations at that site also appear to be elevated above background levels. At half the sites where slimy sculpin were sampled, selenium concentrations were at levels that may cause adverse effects in some species.

  16. Rapid Sediment Accumulation Results in High Methane Effluxes from Coastal Sediments.

    Directory of Open Access Journals (Sweden)

    Matthias Egger

    Full Text Available Globally, the methane (CH4 efflux from the ocean to the atmosphere is small, despite high rates of CH4 production in continental shelf and slope environments. This low efflux results from the biological removal of CH4 through anaerobic oxidation with sulfate in marine sediments. In some settings, however, pore water CH4 is found throughout the sulfate-bearing zone, indicating an apparently inefficient oxidation barrier for CH4. Here we demonstrate that rapid sediment accumulation can explain this limited capacity for CH4 removal in coastal sediments. In a saline coastal reservoir (Lake Grevelingen, The Netherlands, we observed high diffusive CH4 effluxes from the sediment into the overlying water column (0.2-0.8 mol m-2 yr-1 during multiple years. Linear pore water CH4 profiles and the absence of an isotopic enrichment commonly associated with CH4 oxidation in a zone with high rates of sulfate reduction (50-170 nmol cm-3 d-1 both suggest that CH4 is bypassing the zone of sulfate reduction. We propose that the rapid sediment accumulation at this site (~ 13 cm yr-1 reduces the residence time of the CH4 oxidizing microorganisms in the sulfate/methane transition zone (< 5 years, thus making it difficult for these slow growing methanotrophic communities to build-up sufficient biomass to efficiently remove pore water CH4. In addition, our results indicate that the high input of organic matter (~ 91 mol C m-2 yr-1 allows for the co-occurrence of different dissimilatory respiration processes, such as (acetotrophic methanogenesis and sulfate reduction in the surface sediments by providing abundant substrate. We conclude that anthropogenic eutrophication and rapid sediment accumulation likely increase the release of CH4 from coastal sediments.

  17. Application of probabilistic risk assessment: Evaluating remedial alternatives at the Portland Harbor Superfund Site, Portland, Oregon, USA.

    Science.gov (United States)

    Ruffle, Betsy; Henderson, James; Murphy-Hagan, Clare; Kirkwood, Gemma; Wolf, Frederick; Edwards, Deborah A

    2018-01-01

    A probabilistic risk assessment (PRA) was performed to evaluate the range of potential baseline and postremedy health risks to fish consumers at the Portland Harbor Superfund Site (the "Site"). The analysis focused on risks of consuming fish resident to the Site containing polychlorinated biphenyls (PCBs), given that this exposure scenario and contaminant are the primary basis for US Environmental Protection Agency's (USEPA's) selected remedy per the January 2017 Record of Decision (ROD). The PRA used probability distributions fit to the same data sets used in the deterministic baseline human health risk assessment (BHHRA) as well as recent sediment and fish tissue data to evaluate the range and likelihood of current baseline cancer risks and noncancer hazards for anglers. Areas of elevated PCBs in sediment were identified on the basis of a geospatial evaluation of the surface sediment data, and the ranges of risks and hazards associated with pre- and postremedy conditions were calculated. The analysis showed that less active remediation (targeted to areas with the highest concentrations) compared to the remedial alternative selected by USEPA in the ROD can achieve USEPA's interim risk management benchmarks (cancer risk of 10 -4 and noncancer hazard index [HI] of 10) immediately postremediation for the vast majority of subsistence anglers that consume smallmouth bass (SMB) fillet tissue. In addition, the same targeted remedy achieves USEPA's long-term benchmarks (10 -5 and HI of 1) for the majority of recreational anglers. Additional sediment remediation would result in negligible additional risk reduction due to the influence of background. The PRA approach applied here provides a simple but adaptive framework for analysis of risks and remedial options focused on variability in exposures. It can be updated and refined with new data to evaluate and reduce uncertainty, improve understanding of the Site and target populations, and foster informed remedial decision

  18. Measurements of Sediment Transport in the Western Adriatic Sea

    Science.gov (United States)

    Sherwood, C. R.; Hill, P. S.

    2003-12-01

    Instrumented bottom tripods were deployed at two depths (10 and 20 m) off the mouth of the Chienti River in the western Adriatic Sea from November 2002 to May 2003 as part of the EuroSTRATAFORM Po and Apennine Sediment Transport and Accumulation (PASTA) Experiment. Waves, currents, and proxies for suspended-sediment concentrations were measured with upward-looking acoustic Doppler current meters, downward looking pulse-coherent acoustic Doppler profilers, single-point acoustic Doppler velocimeters, and acoustic and optical backscatter sensors. Flow was dominated by the western Adriatic coastal current (WACC) during the experiment. Mean southward alongshore velocity 2 m below the surface was 0.10 m/s at the 10-m site and 0.23 m/s at the 20-m site, and flow was modulated by tides, winds, and fluctuating riverflow. The largest waves (3 m significant height) were generated by winds from the southeast during a Sirocco event in late November that generated one of the few episodes of sustained northward flow and sediment transport. Most of the time, however, sediment resuspension and transport was dominated by Bora events, when downwelling-favorable winds from the northeast generated waves that resuspended sediment and simultaneously enhanced southward flow in the WACC. Mean flow near the bottom was slightly offshore at the 20-m site (0.01 m/s at 3 m above the bottom), but there was no significant correlation between downwelling and wave-induced resuspension, and cross-shelf sediment fluxes were small. The combination of persistent southward flow with low rates of cross-shelf leakage makes the WACC an efficient conduit for sediment past the Chienti region. If these observations are representative of typical winter conditions along the entire western Adriatic, they may help explain the enigmatic development of Holocene shelf-edge clinoforms that have formed hundreds of kilometers south of the Po River, which provides most of the sediment to the Adriatic Sea. Future data

  19. Exploring the concept of web site customization : applications and antecedents

    NARCIS (Netherlands)

    Teerling, M.L.; Huizingh, Eelko K.R.E.

    2006-01-01

    While mass customization is the tailoring of products and services to the needs and wants of individual customers, web site customization is the tailoring of web sites to individual customers’ preferences. Based on a review of site customization applications, the authors propose a model with four

  20. Rapid sedimentation and overpressure in shallow sediments of the Bering Trough, offshore southern Alaska

    Science.gov (United States)

    Daigle, Hugh; Worthington, Lindsay L.; Gulick, Sean P. S.; Van Avendonk, Harm J. A.

    2017-04-01

    Pore pressures in sediments at convergent margins play an important role in driving chemical fluxes and controlling deformation styles and localization. In the Bering Trough offshore Southern Alaska, extreme sedimentation rates over the last 140 kyr as a result of glacial advance/retreats on the continental shelf have resulted in elevated pore fluid pressures in slope sediments overlying the Pamplona Zone fold and thrust belt, the accretionary wedge resulting from subduction of the Yakutat microplate beneath the North American Plate. Based on laboratory experiments and downhole logs acquired at Integrated Ocean Drilling Program Site U1421, we predict that the overpressure in the slope sediments may be as high as 92% of the lithostatic stress. Results of one-dimensional numerical modeling accounting for changes in sedimentation rate over the last 130 kyr predicted overpressures that are consistent with our estimates, suggesting that the overpressure is a direct result of the rapid sedimentation experienced on the Bering shelf and slope. Comparisons with other convergent margins indicate that such rapid sedimentation and high overpressure are anomalous in sediments overlying accretionary wedges. We hypothesize that the shallow overpressure on the Bering shelf/slope has fundamentally altered the deformation style within the Pamplona Zone by suppressing development of faults and may inhibit seismicity by focusing faulting elsewhere or causing deformation on existing faults to be aseismic. These consequences are probably long-lived as it may take several million years for the excess pressure to dissipate.

  1. Sediment transport on the Palos Verdes shelf, California

    Science.gov (United States)

    Ferre, B.; Sherwood, C.R.; Wiberg, P.L.

    2010-01-01

    Sediment transport and the potential for erosion or deposition have been investigated on the Palos Verdes (PV) and San Pedro shelves in southern California to help assess the fate of an effluent-affected deposit contaminated with DDT and PCBs. Bottom boundary layer measurements at two 60-m sites in spring 2004 were used to set model parameters and evaluate a one-dimensional (vertical) model of local, steady-state resuspension, and suspended-sediment transport. The model demonstrated skill (Brier scores up to 0.75) reproducing the magnitudes of bottom shear stress, current speeds, and suspended-sediment concentrations measured during an April transport event, but the model tended to underpredict observed rotation in the bottom-boundary layer, possibly because the model did not account for the effects of temperature-salinity stratification. The model was run with wave input estimated from a nearby buoy and current input from four to six years of measurements at thirteen sites on the 35- and 65-m isobaths on the PV and San Pedro shelves. Sediment characteristics and erodibility were based on gentle wet-sieve analysis and erosion-chamber measurements. Modeled flow and sediment transport were mostly alongshelf toward the northwest on the PV shelf with a significant offshore component. The 95th percentile of bottom shear stresses ranged from 0.09 to 0.16 Pa at the 65-m sites, and the lowest values were in the middle of the PV shelf, near the Whites Point sewage outfalls where the effluent-affected layer is thickest. Long-term mean transport rates varied from 0.9 to 4.8 metric tons m-1 yr-1 along the 65-m isobaths on the PV shelf, and were much higher at the 35-m sites. Gradients in modeled alongshore transport rates suggest that, in the absence of a supply of sediment from the outfalls or PV coast, erosion at rates of ???0.2 mm yr-1 might occur in the region southeast of the outfalls. These rates are small compared to some estimates of background natural sedimentation

  2. Legacy effects of colonial millponds on floodplain sedimentation, bank erosion, and channel morphology, MID-Atlantic, USA

    Science.gov (United States)

    Schenk, E.R.; Hupp, C.R.

    2009-01-01

    Many rivers and streams of the Mid-Atlantic Region, United States (U.S.) have been altered by postcolonial floodplain sedimentation (legacy sediment) associated with numerous milldams. Little Conestoga Creek, Pennsylvania, a tributary to the Susquehanna River and the Chesapeake Bay, is one of these streams. Floodplain sedimentation rates, bank erosion rates, and channel morphology were measured annually during 2004-2007 at five sites along a 28-km length of Little Conestoga Creek with nine colonial era milldams (one dam was still in place in 2007). This study was part of a larger cooperative effort to quantify floodplain sedimentation, bank erosion, and channel morphology in a high sediment yielding region of the Chesapeake Bay watershed. Data from the five sites were used to estimate the annual volume and mass of sediment stored on the floodplain and eroded from the banks for 14 segments along the 28-km length of creek. A bank and floodplain reach based sediment budget (sediment budget) was constructed for the 28 km by summing the net volume of sediment deposited and eroded from each segment. Mean floodplain sedimentation rates for Little Conestoga Creek were variable, with erosion at one upstream site (-5 mm/year) to deposition at the other four sites (highest = 11 mm/year) despite over a meter of floodplain aggradation from postcolonial sedimentation. Mean bank erosion rates range between 29 and 163 mm/year among the five sites. Bank height increased 1 m for every 10.6 m of channel width, from upstream to downstream (R2 = 0.79, p channel and the floodplain. Floodplain sedimentation and bank erosion rates also appear to be affected by the proximity of the segments to one existing milldam, which promotes deposition upstream and scouring downstream. The floodplain and bank along the 28-km reach produced a net mean sediment loss of 5,634 Mg/year for 2004-2007, indicating that bank erosion was exceeding floodplain sedimentation. In particular, the three segments

  3. Sediment diffusion method improves wastewater nitrogen removal in the receiving lake sediments.

    Science.gov (United States)

    Aalto, Sanni L; Saarenheimo, Jatta; Ropponen, Janne; Juntunen, Janne; Rissanen, Antti J; Tiirola, Marja

    2018-07-01

    Sediment microbes have a great potential to transform reactive N to harmless N 2 , thus decreasing wastewater nitrogen load into aquatic ecosystems. Here, we examined if spatial allocation of the wastewater discharge by a specially constructed sediment diffuser pipe system enhanced the microbial nitrate reduction processes. Full-scale experiments were set on two Finnish lake sites, Keuruu and Petäjävesi, and effects on the nitrate removal processes were studied using the stable isotope pairing technique. All nitrate reduction rates followed nitrate concentrations, being highest at the wastewater-influenced sampling points. Complete denitrification with N 2 as an end-product was the main nitrate reduction process, indicating that the high nitrate and organic matter concentrations of wastewater did not promote nitrous oxide (N 2 O) production (truncated denitrification) or ammonification (dissimilatory nitrate reduction to ammonium; DNRA). Using 3D simulation, we demonstrated that the sediment diffusion method enhanced the contact time and amount of wastewater near the sediment surface especially in spring and in autumn, altering organic matter concentration and oxygen levels, and increasing the denitrification capacity of the sediment. We estimated that natural denitrification potentially removed 3-10% of discharged wastewater nitrate in the 33 ha study area of Keuruu, and the sediment diffusion method increased this areal denitrification capacity on average 45%. Overall, our results indicate that sediment diffusion method can supplement wastewater treatment plant (WWTP) nitrate removal without enhancing alternative harmful processes. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Data report: Pennsylvania, New Jersey, and New York. National uranium resource evaluation program, hydrogeochemical and stream sediment reconnaissance

    International Nuclear Information System (INIS)

    Cook, J.R.; Fay, W.M.; Sargent, K.A.

    1982-02-01

    This report presents the results of ground water, stream water, and stream sediment reconnaissance in Pennsylvania, New Jersey, and New York. Ground water samples were collected at 5734 sites in Pennsylvania, 1038 sites in New Jersey, and 4829 sites in New York. Stream sediment samples were collected at 4499 sites in Pennsylvania, 628 sites in New Jersey, and 5696 sites in New York. Stream water samples were collected at 4401 sites in Pennsylvania, 382 sites in New Jersey, and 5047 sites in New York. Neutron activation analyses are given for U, Br, Cl, F, Mn, Na, Al, V, and Dy in ground water and stream water, and for U, Th, Hf, Ce, Fe, Mn, Na, Sc, Ti, V, Al, Dy, Eu, La, Sm, Yb, and Lu in sediments. Supplementary analyses by other techniques are reported for U (extractable), Ag, As, Ba, Be, Ca, Co, Cr, Cu, K, Li, Mg, Mo, Nb, Ni, P, Pb, Se, Sn, Sr, W, Y, and Zn. These analyses were made on 6947 sediment samples. Field measurements and observations are reported for each site. Oak Ridge National Laboratory analyzed sediment samples which were not analyzed by Savannah River Laboratory neutron activation

  5. Sediment carbon and nutrient fluxes from cleared and intact temperate mangrove ecosystems and adjacent sandflats.

    Science.gov (United States)

    Bulmer, Richard H; Schwendenmann, Luitgard; Lohrer, Andrew M; Lundquist, Carolyn J

    2017-12-01

    The loss of mangrove ecosystems is associated with numerous impacts on coastal and estuarine function, including sediment carbon and nutrient cycling. In this study we compared in situ fluxes of carbon dioxide (CO 2 ) from the sediment to the atmosphere, and fluxes of dissolved inorganic nutrients and oxygen across the sediment-water interface, in intact and cleared mangrove and sandflat ecosystems in a temperate estuary. Measurements were made 20 and 25months after mangrove clearance, in summer and winter, respectively. Sediment CO 2 efflux was over two-fold higher from cleared than intact mangrove ecosystems at 20 and 25months after mangrove clearance. The higher CO 2 efflux from the cleared site was explained by an increase in respiration of dead root material along with sediment disturbance following mangrove clearance. In contrast, sediment CO 2 efflux from the sandflat site was negligible (≤9.13±1.18mmolm -2 d -1 ), associated with lower sediment organic matter content. The fluxes of inorganic nutrients (NH 4 + , NO x and PO 4 3- ) from intact and cleared mangrove sediments were low (≤20.37±18.66μmolm -2 h - 1 ). The highest NH 4 + fluxes were measured at the sandflat site (69.21±13.49μmolm -2 h - 1 ). Lower inorganic nutrient fluxes within the cleared and intact mangrove sites compared to the sandflat site were associated with lower abundance of larger burrowing macrofauna. Further, a higher fraction of organic matter, silt and clay content in mangrove sediments may have limited nutrient exchange. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Dam Breach Release of Non-Cohesive Sediments: Channel Response and Recovery Rates

    Science.gov (United States)

    Collins, M. J.; Boardman, G.; Banks, W.; Andrews, M.; Conlon, M.; Dillow, J. J. A.; Gellis, A.; Lowe, S.; McClain, S.; Miller, A. J.; Snyder, N. P.; Wilcock, P. R.

    2014-12-01

    Dam removals featuring unchecked releases of non-cohesive sediments are excellent opportunities to learn more about stream channel response to abrupt increases in bed material supply that can occur deliberately or by natural processes like landslides and volcanic eruptions. Understanding channel response to sediment pulses, including response rates, is essential because human uses of river channels and floodplains are impacted by these events as are aquatic habitats. We had the opportunity to study a dam removal site at the Simkins Dam in Maryland, USA, that shares many important geophysical attributes of another well-studied dam removal in the humid northeast United States [Merrimack Village Dam, New Hampshire; Pearson et al., 2011]. The watershed sizes are the same order of magnitude (102 km2), and at both sites relatively low head dams were removed (~ 3-4 m) and ~60,000 m3 of dominantly sand-sized sediments discharged to low-gradient reaches immediately downstream. Analyzing four years of repeat morphometry and bed sediment grain size surveys at the Simkins site on the Patapsco River, as well as continuous discharge and suspended sediment gaging data, we clearly document a two-phase response in the upstream reach as described by Pearson et al. [2011] for their New Hampshire site and noted at other dam removals [e.g., Major et al., 2012]. In the early phase, approximately 50% of the impounded sediment mass was eroded rapidly over a period of about three months when flows were very modest (Figure 1). After incision to base level and channel widening in the former impoundment, a second phase began when further erosion depended on floods large enough to access impounded sediments more distant from the newly-formed channel. We also found important differences in the upstream responses at the Maryland and New Hampshire sites that appear to be related to valley type (non-glaciated versus glaciated, respectively). Response variances immediately downstream between the

  7. A field study on phytoremediation of dredged sediment contaminated by heavy metals and nutrients: the impacts of sediment aeration.

    Science.gov (United States)

    Wu, Juan; Yang, Lihua; Zhong, Fei; Cheng, Shuiping

    2014-12-01

    Compared to traditional chemical or physical treatments, phytoremediation has proved to be a cost-effective and environmentally sound alternative for remediation of contaminated dredged sediment. A field study was conducted in a sediment disposal site predominantly colonized by Typha angustifolia under different sediment moisture conditions to estimate the phytoremediation effects of dredged sediment. The moisture content was 37.30 % and 48.27 % in aerated and waterlogged sediment, respectively. Total nitrogen (TN) content was higher in the waterlogged sediment than in the aerated sediment. The total Cd contents were lower in aerated sediment, which was mainly resulted from the lower exchangeable fraction of Cd. The bioaccumulation of P, Cu and Pb in T. angustifolia was promoted by waterlogging, and the belowground tissue concentrations and accumulation factors (AFs) of Cu were higher than that of other metals, which can be explained by that Cu is an essential micronutrient for plants. Consistent with many previous studies, T. angustifolia showed higher metal levels in roots than in above-ground tissues at both the sediment conditions. Due to the improved biomass produced in the aerated sediment, the removals of nutrients and the metals by plant harvest were higher from aerated sediment than from waterlogged sediment. It was indicated that maintaining the dredged sediment aerated can avoid release risk and plant uptake of metals, while the opposite management option can promote phytoextraction of these contaminants.

  8. Organochlorinated pesticides in sediments from the Lake Albufera of Valencia (Spain).

    Science.gov (United States)

    Peris, E; Requena, S; de la Guardia, M; Pastor, A; Carrasco, J M

    2005-09-01

    Bottom sediment samples from 121 sites of the Lake Albufera of Valencia were analyzed. Dieldrin, endrin, heptachlor and op'-DDT were not detected (<0.01 ng g(-1)) in 88-93% of the sites. Aldrin and HCB concentration ranges were between <0.01 and 0.1 ng g(-1) in 86% and 94% of the sites, respectively. Heptachlor-epoxide and lindane 95% confidence intervals were 0.2-0.5 and 0.06-0.12, respectively. The greatest average concentration corresponds to pp'-DDE, pp'-DDD and pp'-DDT. The sum of six isomers and derivatives of the DDT average concentration reaches 2.1 ng g(-1), as opposed to 2.7 ng g(-1) for the sum of 13 pesticides considered. In the site with a major contamination, 27.0 ng g(-1) of pp'-DDD and 12.8 ng g(-1) of pp'-DDT were accumulated. The DDE:DDT proportion average was 0.37, indicating an aged DDT contamination. Concentrations of pesticides in sediments were compared to three sediment quality guidelines, and indicated that a low biological effects level can be expected in either sediments or aquatic organisms.

  9. Antifoulant (butyltin and copper) concentrations in sediments from the Great Barrier Reef World Heritage Area, Australia

    International Nuclear Information System (INIS)

    Haynes, David; Loong, Dominica

    2002-01-01

    Antifoulant concentrations are generally low in the Great Barrier Reef, although ship grounding sites present a previously unidentified significant source of antifoulant pollutants in the Great Barrier Reef. - Antifoulant concentrations were determined in marine sediments collected from commercial harbours, marinas, mooring locations on mid-shelf continental islands, and outer reef sites in four regions within the Great Barrier Reef World Heritage Area in 1999. Highest copper concentrations were present in sediments collected from commercial harbour sampling sites (28-233 μg Cu g -1 dry wt.). In contrast, copper concentrations in sediments collected from boat mooring sites on mid-shelf continental islands and outer reef sites were at background concentrations (i.e. -1 dry wt.). Butyltin was only detectable in four of the 42 sediments sampled for analysis, and was only present in sediments collected from commercial harbours (18-1275 ng Sn g -1 dry wt.) and from marinas (4-5 ng Sn g -1 dry wt.). The detection of tributyltin at marina sites implies that this antifoulant may continue to be used illegally on the hulls of smaller recreational vessels. Sediment samples were also collected opportunistically from the site of a 22,000 t cargo ship grounding in May 1999 at Heath Reef, in the far northern Great Barrier Reef. Butyltin concentrations were grossly elevated (660-340,000 ng Sn g -1 dry wt.) at the grounding site. The impact of residual antifoulants at large ship grounding sites should be recognised as a significant, long-term environmental problem unless antfoulant clean-up strategies are undertaken

  10. Soil and Nutrient Loss Following Site Preparation Burning

    Science.gov (United States)

    J.P. Field; E.A. Carter

    2000-01-01

    Sediment loss and nutrient cpncentrations in runoff were evaluated to determine the effects of site preparation burning on a recently harvested loblolly pine (Pinus taeda L.) site in east Texas. Sediment and nutrient losses prior to treatment were approximately the same from control plots and pretreatment burn plots. Nutrient analysis of runoff...

  11. The behavioural characteristics of sediment properties and their implications for sediment fingerprinting as an approach for identifying sediment sources in river basins

    Science.gov (United States)

    Koiter, A. J.; Owens, P. N.; Petticrew, E. L.; Lobb, D. A.

    2013-10-01

    Sediment fingerprinting is a technique that is increasingly being used to improve the understanding of sediment dynamics within river basins. At present, one of the main limitations of the technique is the ability to link sediment back to their sources due to the non-conservative nature of many of the sediment properties. The processes that occur between the sediment source locations and the point of collection downstream are not well understood or quantified and currently represent a black-box in the sediment fingerprinting approach. The literature on sediment fingerprinting tends to assume that there is a direct connection between sources and sinks, while much of the broader environmental sedimentology literature identifies that numerous chemical, biological and physical transformations and alterations can occur as sediment moves through the landscape. The focus of this paper is on the processes that drive particle size and organic matter selectivity and biological, geochemical and physical transformations and how understanding these processes can be used to guide sampling protocols, fingerprint selection and data interpretation. The application of statistical approaches without consideration of how unique sediment fingerprints have developed and how robust they are within the environment is a major limitation of many recent studies. This review summarises the current information, identifies areas that need further investigation and provides recommendations for sediment fingerprinting that should be considered for adoption in future studies if the full potential and utility of the approach are to be realised.

  12. Legacy effects of colonial millponds on floodplain sedimentation, bank erosion, and channel morphology, MID-Atlantic, USA

    Science.gov (United States)

    Schenk, E.R.; Hupp, C.R.

    2009-01-01

    Many rivers and streams of the Mid-Atlantic Region, United States (U.S.) have been altered by postcolonial floodplain sedimentation (legacy sediment) associated with numerous milldams. Little Conestoga Creek, Pennsylvania, a tributary to the Susquehanna River and the Chesapeake Bay, is one of these streams. Floodplain sedimentation rates, bank erosion rates, and channel morphology were measured annually during 2004-2007 at five sites along a 28-km length of Little Conestoga Creek with nine colonial era milldams (one dam was still in place in 2007). This study was part of a larger cooperative effort to quantify floodplain sedimentation, bank erosion, and channel morphology in a high sediment yielding region of the Chesapeake Bay watershed. Data from the five sites were used to estimate the annual volume and mass of sediment stored on the floodplain and eroded from the banks for 14 segments along the 28-km length of creek. A bank and floodplain reach based sediment budget (sediment budget) was constructed for the 28 km by summing the net volume of sediment deposited and eroded from each segment. Mean floodplain sedimentation rates for Little Conestoga Creek were variable, with erosion at one upstream site (-5 mm/year) to deposition at the other four sites (highest = 11 mm/year) despite over a meter of floodplain aggradation from postcolonial sedimentation. Mean bank erosion rates range between 29 and 163 mm/year among the five sites. Bank height increased 1 m for every 10.6 m of channel width, from upstream to downstream (R2 = 0.79, p scouring downstream. The floodplain and bank along the 28-km reach produced a net mean sediment loss of 5,634 Mg/year for 2004-2007, indicating that bank erosion was exceeding floodplain sedimentation. In particular, the three segments between the existing dam and the confluence with the Conestoga River (32% of the studied reach) account for 97% of the measured net sediment budget. Future research directed at understanding channel

  13. Factors influencing mercury in freshwater surface sediments of northeastern North America

    Science.gov (United States)

    Kamman, N.C.; Chalmers, A.; Clair, T.A.; Major, A.; Moore, R.B.; Norton, S.A.; Shanley, J.B.

    2005-01-01

    We report on an inventory and analysis of sediment mercury (Hg) concentrations from 579 sites across northeastern North America. Sediment Hg concentrations ranged from the limit of detection ca. 0.01-3.7 ??g g -1 (dry weight, d.w.), and the average concentration was 0.19 ??g g-1 (d.w.) Sediment methylmercury concentrations ranged from 0.15 to 21 ng g-1 (d.w.) and the mean concentration was 3.83 ng g -1 (d.w.). Total Hg concentrations (HgT) were greatest in lakes > reservoirs > rivers, although the proportion of Hg as methylmercury showed an inverse pattern. Total Hg was weakly and positively correlated with the sediment organic matter and percent of watershed as forested land, and weakly and negatively correlated with sediment solids content, drainage area, and agricultural land. Sediment methylmercury concentrations were weakly and positively correlated to wetland area, and weakly and negatively correlated to drainage area. Methylmercury, expressed as a percentage of HgT was positively correlated to agricultural land area. For sites with co-located sediment and fish-tissue sampling results, there was no relationship between sediment Hg and fish-tissue Hg. Finally, our data indicate that at least 44% of waters across the region have sediment HgT concentrations in excess of Canadian and United States minimum sediment contaminant guidelines for the protection of aquatic biota. ?? 2005 Springer Science+Business Media, Inc.

  14. Event-based soil loss models for construction sites

    Science.gov (United States)

    Trenouth, William R.; Gharabaghi, Bahram

    2015-05-01

    The elevated rates of soil erosion stemming from land clearing and grading activities during urban development, can result in excessive amounts of eroded sediments entering waterways and causing harm to the biota living therein. However, construction site event-based soil loss simulations - required for reliable design of erosion and sediment controls - are one of the most uncertain types of hydrologic models. This study presents models with improved degree of accuracy to advance the design of erosion and sediment controls for construction sites. The new models are developed using multiple linear regression (MLR) on event-based permutations of the Universal Soil Loss Equation (USLE) and artificial neural networks (ANN). These models were developed using surface runoff monitoring datasets obtained from three sites - Greensborough, Cookstown, and Alcona - in Ontario and datasets mined from the literature for three additional sites - Treynor, Iowa, Coshocton, Ohio and Cordoba, Spain. The predictive MLR and ANN models can serve as both diagnostic and design tools for the effective sizing of erosion and sediment controls on active construction sites, and can be used for dynamic scenario forecasting when considering rapidly changing land use conditions during various phases of construction.

  15. Conceptualizing the role of sediment in sustaining ecosystem services: Sediment-ecosystem regional assessment (SEcoRA).

    Science.gov (United States)

    Apitz, Sabine E

    2012-01-15

    There is a growing trend to include a consideration of ecosystem services, the benefits that people obtain from ecosystems, within decision frameworks. Not more than a decade ago, sediment management efforts were largely site-specific and held little attention except in terms of managing contaminant inputs and addressing sediments as a nuisance at commercial ports and harbors. Sediments figure extensively in the Millennium Ecosystem Assessment; however, contaminated sediment is not the dominant concern. Rather, the focus is on land and water use and management on the landscape scale, which can profoundly affect soil and sediment quality, quantity and fate. Habitat change and loss, due to changes in sediment inputs, whether reductions (resulting in the loss of beaches, storm protection, nutrient inputs, etc.) or increases (resulting in lake, reservoir and wetland infilling, coral reef smothering, etc.); eutrophication and reductions in nutrient inputs, and disturbance due to development and fishing practices are considered major drivers, with significant consequences for biodiversity and the provision and resilience of ecosystem functions and services. As a mobile connecting medium between various parts of the ecosystem via the hydrocycle, sediments both contaminated and uncontaminated, play both positive and negative roles in the viability and sustainability of social, economic, and ecological objectives. How these roles are interpreted depends upon whether sediment status (defined in terms of sediment quality, quantity, location and transport) is appropriate to the needs of a given endpoint; understanding and managing the dynamic interactions of sediment status on a diverse range of endpoints at the landscape or watershed scale should be the focus of sediment management. This paper seeks to provide a language and conceptual framework upon which sediment-ecosystem regional assessments (SEcoRAs) can be developed in support of that goal. Copyright © 2011 Elsevier B

  16. New Technique for Speciation of Uranium in Sediments Following Acetate-Stimulated Bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    2011-06-22

    Acetate-stimulated bioremediation is a promising new technique for sequestering toxic uranium contamination from groundwater. The speciation of uranium in sediments after such bioremediation attempts remains unknown as a result of low uranium concentration, and is important to analyzing the stability of sequestered uranium. A new technique was developed for investigating the oxidation state and local molecular structure of uranium from field site sediments using X-Ray Absorption Spectroscopy (XAS), and was implemented at the site of a former uranium mill in Rifle, CO. Glass columns filled with bioactive Rifle sediments were deployed in wells in the contaminated Rifle aquifer and amended with a hexavalent uranium (U(VI)) stock solution to increase uranium concentration while maintaining field conditions. This sediment was harvested and XAS was utilized to analyze the oxidation state and local molecular structure of the uranium in sediment samples. Extended X-Ray Absorption Fine Structure (EXAFS) data was collected and compared to known uranium spectra to determine the local molecular structure of the uranium in the sediment. Fitting was used to determine that the field site sediments did not contain uraninite (UO{sub 2}), indicating that models based on bioreduction using pure bacterial cultures are not accurate for bioremediation in the field. Stability tests on the monomeric tetravalent uranium (U(IV)) produced by bioremediation are needed in order to assess the efficacy of acetate-stimulation bioremediation.

  17. Radiocarbon dating, chronologic framework, and changes in accumulation rates of holocene estuarine sediments from Chesapeake Bay

    Science.gov (United States)

    Colman, Steven M.; Baucom, P.C.; Bratton, J.F.; Cronin, T. M.; McGeehin, J.P.; Willard, D.; Zimmerman, A.R.; Vogt, P.R.

    2002-01-01

    Rapidly accumulating Holocene sediments in estuaries commonly are difficult to sample and date. In Chesapeake Bay, we obtained sediment cores as much as 20 m in length and used numerous radiocarbon ages measured by accelarator mass spectrometry methods to provide the first detailed chronologies of Holocene sediment accumulation in the bay. Carbon in these sediments is a complex mixture of materials from a variety of sources. Analyses of different components of the sediments show that total organic carbon ages are largely unreliable, because much of the carbon (including coal) has been transported to the bay from upstream sources and is older than sediments in which it was deposited. Mollusk shells (clams, oysters) and foraminifera appear to give reliable results, although reworking and burrowing are potential problems. Analyses of museum specimens collected alive before atmospheric nuclear testing suggest that the standard reservoir correction for marine samples is appropriate for middle to lower Chesapeake Bay. The biogenic carbonate radiocarbon ages are compatible with 210 Pb and 137 Cs data and pollen stratigraphy from the same sites. Post-settlement changes in sediment transport and accumulation is an important environmental issue in many estuaries, including the Chesapeake. Our data show that large variations in sediment mass accumulation rates occur among sites. At shallow water sites, local factors seem to control changes in accumulation rates with time. Our two relatively deep-water sites in the axial channel of the bay have different long-term average accumulation rates, but the history of sediment accumulation at these sites appears to reflect overall conditions in the bay. Mass accumulation rates at the two deep-water sites rapidly increased by about fourfold coincident with widespread land clearance for agriculture in the Chesapeake watershed.

  18. Field application of activated carbon amendment for in-situ stabilization of polychlorinated biphenyls in marine sediment.

    Science.gov (United States)

    Cho, Yeo-Myoung; Ghosh, Upal; Kennedy, Alan J; Grossman, Adam; Ray, Gary; Tomaszewski, Jeanne E; Smithenry, Dennis W; Bridges, Todd S; Luthy, Richard G

    2009-05-15

    We report results on the first field-scale application of activated carbon (AC) amendment to contaminated sediment for in-situ stabilization of polychlorinated biphenyls (PCBs). The test was performed on a tidal mud flat at South Basin, adjacent to the former Hunters Point Naval Shipyard, San Francisco Bay, CA. The major goals of the field study were to (1) assess scale up of the AC mixing technology using two available, large-scale devices, (2) validate the effectiveness of the AC amendment at the field scale, and (3) identify possible adverse effects of the remediation technology. Also, the test allowed comparison among monitoring tools, evaluation of longer-term effectiveness of AC amendment, and identification of field-related factors that confound the performance of in-situ biological assessments. Following background pretreatment measurements, we successfully incorporated AC into sediment to a nominal 30 cm depth during a single mixing event, as confirmed by total organic carbon and black carbon contents in the designated test plots. The measured AC dose averaged 2.0-3.2 wt% and varied depending on sampling locations and mixing equipment. AC amendment did not impact sediment resuspension or PCB release into the water column over the treatment plots, nor adversely impactthe existing macro benthic community composition, richness, or diversity. The PCB bioaccumulation in marine clams was reduced when exposed to sediment treated with 2% AC in comparison to the control plot Field-deployed semi permeable membrane devices and polyethylene devices showed about 50% reduction in PCB uptake in AC-treated sediment and similar reduction in estimated pore-water PCB concentration. This reduction was evident even after 13-month post-treatment with then 7 months of continuous exposure, indicating AC treatment efficacy was retained for an extended period. Aqueous equilibrium PCB concentrations and PCB desorption showed an AC-dose response. Field-exposed AC after 18 months

  19. Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour

    International Nuclear Information System (INIS)

    Lee, Cheng-Hsien; Low, Ying Min; Chiew, Yee-Meng

    2016-01-01

    Sediment transport is fundamentally a two-phase phenomenon involving fluid and sediments; however, many existing numerical models are one-phase approaches, which are unable to capture the complex fluid-particle and inter-particle interactions. In the last decade, two-phase models have gained traction; however, there are still many limitations in these models. For example, several existing two-phase models are confined to one-dimensional problems; in addition, the existing two-dimensional models simulate only the region outside the sand bed. This paper develops a new three-dimensional two-phase model for simulating sediment transport in the sheet flow condition, incorporating recently published rheological characteristics of sediments. The enduring-contact, inertial, and fluid viscosity effects are considered in determining sediment pressure and stresses, enabling the model to be applicable to a wide range of particle Reynolds number. A k − ε turbulence model is adopted to compute the Reynolds stresses. In addition, a novel numerical scheme is proposed, thus avoiding numerical instability caused by high sediment concentration and allowing the sediment dynamics to be computed both within and outside the sand bed. The present model is applied to two classical problems, namely, sheet flow and scour under a pipeline with favorable results. For sheet flow, the computed velocity is consistent with measured data reported in the literature. For pipeline scour, the computed scour rate beneath the pipeline agrees with previous experimental observations. However, the present model is unable to capture vortex shedding; consequently, the sediment deposition behind the pipeline is overestimated. Sensitivity analyses reveal that model parameters associated with turbulence have strong influence on the computed results.

  20. Environmental monitoring of Columbia River sediments: Grain-size distribution and contaminant association

    Energy Technology Data Exchange (ETDEWEB)

    Blanton, M.L.; Gardiner, W.W.; Dirkes, R.L.

    1995-04-01

    Based on the results of this study and literature review, the following conclusions can be made: Sediment grain size and TOC (total organic carbon) influence contaminant fate and transport (in general, sediments with higher TOC content and finer grain-size distribution can have higher contaminant burdens than sediments from a given river section that have less TOC and greater amounts of coarse-grained sediments). Physiochemical sediment characteristics are highly variable among monitoring sites along the Columbia River. Sediment grain characterization and TOC analysis should be included in interpretations of sediment-monitoring data.

  1. Environmental monitoring of Columbia River sediments: Grain-size distribution and contaminant association

    International Nuclear Information System (INIS)

    Blanton, M.L.; Gardiner, W.W.; Dirkes, R.L.

    1995-04-01

    Based on the results of this study and literature review, the following conclusions can be made: Sediment grain size and TOC (total organic carbon) influence contaminant fate and transport (in general, sediments with higher TOC content and finer grain-size distribution can have higher contaminant burdens than sediments from a given river section that have less TOC and greater amounts of coarse-grained sediments). Physiochemical sediment characteristics are highly variable among monitoring sites along the Columbia River. Sediment grain characterization and TOC analysis should be included in interpretations of sediment-monitoring data

  2. Equilibrium sampling to determine the thermodynamic potential for bioaccumulation of persistent organic pollutants from sediment.

    Science.gov (United States)

    Jahnke, Annika; MacLeod, Matthew; Wickström, Håkan; Mayer, Philipp

    2014-10-07

    Equilibrium partitioning (EqP) theory is currently the most widely used approach for linking sediment pollution by persistent hydrophobic organic chemicals to bioaccumulation. Most applications of the EqP approach assume (I) a generic relationship between organic carbon-normalized chemical concentrations in sediments and lipid-normalized concentrations in biota and (II) that bioaccumulation does not induce levels exceeding those expected from equilibrium partitioning. Here, we demonstrate that assumption I can be obviated by equilibrating a silicone sampler with chemicals in sediment, measuring chemical concentrations in the silicone, and applying lipid/silicone partition ratios to yield concentrations in lipid at thermodynamic equilibrium with the sediment (CLip⇌Sed). Furthermore, we evaluated the validity of assumption II by comparing CLip⇌Sed of selected persistent, bioaccumulative and toxic pollutants (polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB)) to lipid-normalized concentrations for a range of biota from a Swedish background lake. PCBs in duck mussels, roach, eel, pikeperch, perch and pike were mostly below the equilibrium partitioning level relative to the sediment, i.e., lipid-normalized concentrations were ≤CLip⇌Sed, whereas HCB was near equilibrium between biota and sediment. Equilibrium sampling allows straightforward, sensitive and precise measurement of CLip⇌Sed. We propose CLip⇌Sed as a metric of the thermodynamic potential for bioaccumulation of persistent organic chemicals from sediment useful to prioritize management actions to remediate contaminated sites.

  3. Radiotracer investigations for sediment transport in ports of India

    International Nuclear Information System (INIS)

    Pant, H.J.; Sharma, V.K.; Goswami, Sunil; Singh, Gursharan

    2013-01-01

    The knowledge of mixing and transport of sediments in coastal region is of vital importance for evaluating suitability of dumping site for dredged sediments produced during maintenance of shipping channels, expansion of existing projects and construction of new projects. Gamma-emitting radiotracers are commonly used for investigation of movement of sediments on seabed using Scandium-46 (scandium glass powder) as radiotracer. The radiotracer is injected on seabed at a desired location and its movement followed over a period of time using waterproof NaI(Tl) scintillation detectors. The recorded data is analyzed to obtain transport parameters and utilized for assessing the suitability of the dumping sites and optimization of the dredging operations. About 70 large-scale investigations have been carried out in different ports in India leading to significant economical benefits to the Ports. Present paper discusses various aspects of the radiotracer technique for sediment transport, methodology of data analysis and a specific case study. (author)

  4. Toxicity of sediments and pore water from Brunswick Estuary, Georgia

    Science.gov (United States)

    Winger, Parley V.; Lasier, Peter J.; Geitner, Harvey

    1993-01-01

    A chlor-alkali plant in Brunswick, Georgia, USA, discharged >2 kg mercury/d into a tributary of the Turtle River-Brunswick Estuary from 1966 to 1971. Mercury concentrations in sediments collected in 1989 along the tributary near the chlor-alkali plant ranged from 1 to 27 μg/g (dry weight), with the highest concentrations found in surface (0–8 cm) sediments of subtidal zones in the vicinity of the discharge site. Toxicity screening in 1990 using Microtox® bioassays on pore water extracted on site from sediments collected at six stations distributed along the tributary indicated that pore water was highly toxic near the plant discharge. Ten-day toxicity tests on pore water from subsequent sediment samples collected near the plant discharge confirmed high toxicity to Hyalella azteca, and feeding activity was significantly reduced in whole-sediment tests. In addition to mercury in the sediments, other metals (chromium, lead, and zinc) exceeded 50 μg/g, and polychlorobiphenyl (PCB) concentrations ranged from 67 to 95 μg/g. On a molar basis, acid-volatile sulfide concentrations (20–45 μmol/g) in the sediments exceeded the metal concentrations. Because acid-volatile sulfides bind with cationic metals and form metal sulfides, which are generally not bioavailable, toxicities shown by these sediments were attributed to the high concentrations of PCBs and possibly methylmercury.

  5. Kinetics and reversibility of radiocaesium solid/liquid partitioning in sediments

    International Nuclear Information System (INIS)

    Comans, R.N.J.

    1998-01-01

    The kinetics and reversibility of radiocaesium solid/liquid partitioning in sediments have been reviewed and interpreted in terms of a mechanistic framework. This framework is based on the premise that radiocaesium is almost exclusively and highly-selectively bound to the frayed particle edges of illitic clay minerals in the sediments. Several processes with distinctly different rates can be distinguished in radiocaesium sorption to sediments. 2- and 3-box kinetic models can describe both the overall solid/liquid partitioning in sediments and the reversible (exchangeable) and irreversible (nonexchangeable or 'fixed') fractions of radiocaesium in sediments over time scales relevant for natural aquatic systems. The obtained rate parameters indicate that reversible partitioning of radiocaesium dominates over the first few days following a contamination event, whereas irreversible kinetics becomes important over time scales of weeks to months. The slow process, which reduces the exchangeability of sediment-bound radiocaesium over time, is believed to result from a migration of radiocaesium from exchangeable sites on the frayed edges of illite towards less-exchangeable interlayer sites. Long-term extraction of radiocaesium from historically contaminated sediments has given evidence for a reverse (remobilization) process with a half-life of the order of tens of years. These findings suggest that the long-term exchangeability of radiocaesium in sediments may be higher than the few % which is generally assumed. (orig.)

  6. Ecotoxicological risk assessment linked to infilling quarries with treated dredged seaport sediments.

    Science.gov (United States)

    Perrodin, Yves; Donguy, Gilles; Bazin, Christine; Volatier, Laurence; Durrieu, Claude; Bony, Sylvie; Devaux, Alain; Abdelghafour, Mohammed; Moretto, Robert

    2012-08-01

    The dredged sediments of polluted seaports now raise complex management problems since it is no longer possible to discharge them into the sea. This results in the need to manage them on land, raising other types of technical, economic and environmental problems. Regarding the technical and economic dimensions, traditional waste treatment methods have proved to be poorly adapted, due to very high costs and low absorbable volumes. In this context, filling quarries in coastal areas with treated sediments could represent an interesting alternative for these materials. Nevertheless, for the environmental dimension, it is necessary to demonstrate that this possibility is harmless to inland ecosystems. Consequently, a specific ecotoxicological risk assessment methodology has been formulated and tested on three sediments taken from seaboards of France, in view to providing an operational and usable tool for the prior validation of any operation to fill quarries with treated seaport sediments. This method incorporates the formulation of a global conceptual model of the scenario studied and the definition of protocols for each of its steps: the characterisation of exposures (based on a simulation of sediment deposit), the characterisation of effects (via the study of sediments ecotoxicity), and the final ecotoxicological risk assessment performed as a calculation of a risk quotient. It includes the implementation in parallel of two types of complementary approach: the "substances" approach derived from the European methodology for assessing new substances placed on the market, and the "matrix" approach which is similar to methods developed in France to assess ecological risks in other domains (waste management, polluted site management, …). The application of this dual approach to the three sediments tested led to conclude with reliability that the project to deposit sediments "1" and "2" presented a low risk for the peripheral aquatic ecosystems while sediment "3

  7. Holocene and Late Glacial sedimentation near steep slopes in southern Lake Baikal

    Directory of Open Access Journals (Sweden)

    Michael Sturm

    2015-07-01

    Full Text Available We here present new data on sedimentation at and near the steep north-slopes of southern Lake Baikal. Short sediment cores were taken at 550 m and at 1366 m water depth, within 3600 m offshore Cape Ivanovskii at the station of the Baikal Deep Underwater NEUTRINO Telescope. The sediments within 3600 m off the northern coast of Southern Lake Baikal are dominated by pelagic deposition. Our data reveal surprisingly little influence from terrigenous material from adjacent coastal areas, tributaries and their catchment. At the shallow-water site (at 550 m water depth, 700 m off shore just 27 cm thick homogenous sediments have accumulated during the Holocene on top of Pleistocene deposits resulting in Holocene sedimentation rates of 0.003 cm a-1. The very low rates are caused by long-term persistent winnowing of fine particles caused by week contour currents along the slope. The uppermost sediments are oxidized down to 22 cm. Very low concentrations of Corg, Sibio and Ntot in Pleistocene sediments increase dramatically within the Holocene. The heavy mineral fraction of the shallow-water sediments contains up to 33.6 % olivine and up to 2.4 % spinel. These rare minerals originate from white marbles of the nearby coastal outcrop Belaya Vyemka of the Early Precambrian Sharyzalgaiskaya Series. At the deep-water site (at 1366 m water depth, 3600 m off shore Holocene sedimentation rates are 10-times higher (0.036 cm a-1. Sediment oxidation occurs just within the uppermost 2 cm. Of the two rare type minerals of the Sharyzalgaiskaya Series spinel does not occur at all and olivine is represented by very diminished concentrations. This indicates insignificant influx of terrestrial material from the nearby shore to the deep-water site . Distal turbidites of far-off sources are intercalated to pelagic sediments at the deep-water site. Breakdown events of deltas at the SE- and S-coast of the basin are suggested to be responsible for the formation of the turbidites

  8. Site characterization design and techniques used at the Southern Shipbuilding Corporation site

    International Nuclear Information System (INIS)

    Mueller, J.P.; Geraghty, C.A.; Moore, G.W.; Mullins, J.R.

    1995-01-01

    The Southern Shipbuilding Corporation (SSC) site is an inactive barge/ship manufacturing and repair facility situated on approximately 54 acres in Slidell, St. Tammany Parish, Louisiana. Two unlined surface impoundments (North and South impoundments) are situated on the northwest portion of the site and are surrounded on three sides by Bayou Bonfouca. These impoundments are the sources of carcinogenic polynuclear aromatic hydrocarbon (CPAH) contamination at the site. Inadequate containment has resulted in the release of impoundment wastes into the bayou. To evaluate potential response alternatives for the site, an Engineering Evaluation/Cost Analysis (EE/CA) field investigation was conducted from July through October 1994. A two phase sampling approach was used in combination with innovative and traditional sampling techniques, field screening technologies, and exploitation of the visual characteristics of the waste to determine the extent of waste migration with limited off-site laboratory confirmation. A skid-mounted mobile drilling unit, secured to a specialized sampling platform designed for multiple applications, was used for collection of sediment cores from the bayou as well as tarry sludge cores from the impoundments. Field screening of core samples was accomplished on site using an organic vapor analyzer and a total petroleum hydrocarbon (TPH) field analyzer. Pollutants of concern include metals, cyanide, dioxin, and organic compounds. This paper presents details on the sampling design and characterization techniques used to accomplish the EE/CA field investigation

  9. Effects of dredging operations on sediment quality. Contaminant mobilization in dredged sediments from the Port of Santos, SP, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Ronaldo J.; Santos, Fernando C.; Mozeto, Antonio A. [Lab. de Biogeoquimica Ambiental, Dept. de Quimica, Univ. Federal de Sao Carlos, Sao Paulo, SP (Brazil); Abessa, Denis M.S.; Maranho, Luciane A.; Davanso, Marcela B. [Campus Experimental do Litoral Paulista, UNESP - Univ. Estadual Paulista ' Julio de Mesquita Filho' , Sao Paulo, SP (Brazil); Nascimento, Marcos R.L. do [Lab. de Pocos de Caldas (LAPOC), CNEN-Comissao Nacional de Energia Nuclear, MG (Brazil)

    2009-10-15

    Background, aim, and scope Contaminated sediments are a worldwide problem, and mobilization of contaminants is one of the most critical issues in environmental risk assessment insofar as dredging projects are concerned. The investigation of how toxic compounds are mobilized during dredging operations in the channel of the Port of Santos, Brazil, was conducted in an attempt to assess changes in the bioavailability and toxicity of these contaminants. Materials and methods Bulk sediment samples and their interstitial waters and elutriates were subjected to chemical evaluation and ecotoxicological assessment. Samples were collected from the channel before dredging, from the dredge's hopper, and from the disposal site and its surroundings. Results The results indicate that the bulk sediments from the dredging site are contaminated moderately with As, Pb, and Zn and severely with Hg, and that polycyclic aromatic hydrocarbon (PAH) concentrations are relatively high. Our results also show a 50% increase in PAH concentrations in suspended solids in the water collected from the hopper dredge. This finding is of great concern, since it refers to the dredge overflow water which is pumped back into the ecosystem. Acute toxicity tests on bulk sediment using the amphipod Tiburonella viscana showed no toxicity, while chronic tests with the sea urchin Lytechinus variegatus showed toxicity in the interstitial waters and elutriates. Results are compared with widely used sediment quality guidelines and with a sediment quality assessment scheme based on various lines of evidence. Conclusions The data presented here indicate that the sediments collected in this port show a certain degree of contamination, especially those from the inner part of the channel. The classification established in this study indicated that sediments from the dredged channel are impacted detrimentally and that sea disposal may disperse contaminants. According to this classification, the sediments are

  10. Assessment of the ecotoxicity of urban estuarine sediment using benthic and pelagic copepod bioassays

    Directory of Open Access Journals (Sweden)

    Maria P. Charry

    2018-05-01

    Full Text Available Urban estuarine sediments are sinks to a range of contaminants of anthropogenic origin, and a key challenge is to characterize the risk of these compounds to receiving environments. In this study, the toxicity of urban estuarine sediments was tested using acute and chronic bioassays in the benthic harpacticoid Quinquelaophonte sp., and in the planktonic calanoid Gladioferens pectinatus, two New Zealand copepod species. The sediment samples from the estuary tributary sites significantly impacted reproduction in Quinquelaophonte sp. However, results from one of the estuary sites were not significantly different to those from the tributaries sites, suggesting that chemicals other than trace metals, polycyclic aromatic hydrocarbons and ammonia may be the causative stressors. Sediment elutriate samples had significant effects on reproductive endpoints in G. pectinatus, and on the induction of DNA damage in cells, as shown by the comet assay. The results indicate that sediment contamination at the Ahuriri Estuary has the potential to impact biological processes of benthic and pelagic organisms. The approach used provides a standardized methodology to assess the toxicity of estuarine sediments.

  11. Assessment of the ecotoxicity of urban estuarine sediment using benthic and pelagic copepod bioassays.

    Science.gov (United States)

    Charry, Maria P; Keesing, Vaughan; Costello, Mark; Tremblay, Louis A

    2018-01-01

    Urban estuarine sediments are sinks to a range of contaminants of anthropogenic origin, and a key challenge is to characterize the risk of these compounds to receiving environments. In this study, the toxicity of urban estuarine sediments was tested using acute and chronic bioassays in the benthic harpacticoid Quinquelaophonte sp., and in the planktonic calanoid Gladioferens pectinatus , two New Zealand copepod species. The sediment samples from the estuary tributary sites significantly impacted reproduction in Quinquelaophonte sp. However, results from one of the estuary sites were not significantly different to those from the tributaries sites, suggesting that chemicals other than trace metals, polycyclic aromatic hydrocarbons and ammonia may be the causative stressors. Sediment elutriate samples had significant effects on reproductive endpoints in G. pectinatus , and on the induction of DNA damage in cells, as shown by the comet assay. The results indicate that sediment contamination at the Ahuriri Estuary has the potential to impact biological processes of benthic and pelagic organisms. The approach used provides a standardized methodology to assess the toxicity of estuarine sediments.

  12. Application of remote sensing technology for studying littoral sediment dynamics

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.; Wagle, B.G.

    component image were used for area 'A' and 'B' respectively. The behaviour of sediment laden plumes was examined in detail to understand the distribution and dispersion of suspended sediments. Based on tonal and textural variation, five distinct types...

  13. Sediment Transport Capacity and Channel Processes in a Humid Tropical Montane River - Rio Pacuare, Costa Rica

    Science.gov (United States)

    Lind, P.; McDowell, P. F.

    2017-12-01

    Investigating sediment transport capacity as well as the spatial and temporal variations of sediment flux are critical component of river research, especially for applications in resource management and conservation, hazards assessment and planning, and riverine ecology. The bedload fraction of sediment transported through montane rivers often defines channel and bed form processes. It is understood that humid tropical montane rivers are capable of producing some of the largest quantities of sediment per unit drainage area. Bedload flux reported on a few Southeast Asian humid tropical montane rivers show that bedload constituted 16-75% of the total sediment load - this is notably higher than the generally accepted 10% of a channel's sediment load. However, to date almost all of the research done on sediment transport in humid tropical systems has focused on suspended load. This study presents annual bedload transport rate estimates for six field sites distributed within 45 river kilometers (Rkm) of the montane portion of the Rio Pacuare, located in the Talamanca Mountains of Costa Rica. This research reveals that flows capable of mobilizing the D84 occur on average at least once but often multiple times a year in this river system. The Rio Pacuare has a sufficient supply of sediment to meet its high transport capacity needs. As a result, large active bars composed of imbricated boulders define channel form at moderate and low flows throughout the study area. Differences in the magnitude, as well as the spatial and temporal variations of sediment flux at each field site are discussed in relation to stream power, and annual/inter-annual precipitation patterns. A unique mix of field and remote sensing techniques were applied to address these questions and to overcome some of the challenges of tropical river research. For example, due to the large grain size and high stream energy, grain mobilization and validation of modeled shear stress requirements for transport

  14. An alternative radiometric method for calculating the sedimentation rates: Application to an intertidal region (SW of Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Ligero, R.A., E-mail: rufino.ligero@uca.e [Departamento de Fisica Aplicada, Universidad de Cadiz, 11510 Puerto Real, Cadiz (Spain); Casas-Ruiz, M. [Departamento de Fisica Aplicada, Universidad de Cadiz, 11510 Puerto Real, Cadiz (Spain); Barrera, M. [Departamento de Medio Ambiente, CIEMAT, Madrid 28040 (Spain); Barbero, L. [Departamento de Ciencias de la Tierra, Universidad de Cadiz, 11510 Puerto Real (Spain); Melendez, M.J. [Departamento de Fisica Aplicada, Universidad de Cadiz, 11510 Puerto Real, Cadiz (Spain)

    2010-09-15

    A new method using the inventory determined for the activity of the radionuclide {sup 137}Cs, coming from global radioactive fallout has been utilised to calculate the sedimentation rates. The method has been applied in a wide intertidal region in the Bay of Cadiz Natural Park (SW Spain). The sedimentation rates estimated by the {sup 137}Cs inventory method ranged from 0.26 cm/year to 1.72 cm/year. The average value of the sedimentation rate obtained is 0.59 cm/year, and this rate has been compared with those resulting from the application of the {sup 210}Pb dating technique. A good agreement between the two procedures has been found. From the study carried out, it has been possible for the first time, to draw a map of sedimentation rates for this zone where numerous physico-chemical, oceanographic and ecological studies converge, since it is situated in a region of great environmental interest. This area, which is representative of common environmental coastal scenarios, is particularly sensitive to perturbations related to climate change, and the results of the study will allow to make short and medium term evaluations of this change.

  15. Second workshop of I.A.G./A.I.G. SEDIBUD - Sediment Budgets in Cold Environments: Sediment fluxes and sediment budgets in changing high-latitude and high-altitude cold environments

    Energy Technology Data Exchange (ETDEWEB)

    Beylich, Achim A; Lamoureux, Scott F; Decaulne, Armelle

    2007-07-01

    This Second Workshop of the I.A.G./A.I.G. Working Group SEDIBUD (Sediment Budgets in Cold Environments) builds on four previous ESF SEDIFLUX Science Meetings held in Saudarkrokur (Iceland) in June 2004, Clermont-Ferrand (France) in January 2005, Durham (UK) in December 2005 and Trondheim (Norway) in the end of October/beginning of November 2006. A first kick-off Meeting of the new I.A.G./A.I.G. SEDIBUD Workshop. The theme of this Second I.A.G./A.I.G. SEDIBUD Workshop is Sediment FLuxes and Sediment Budgets in Changing High-Latitude Cold Environments. The Workshop is split between scientific paper and poster presentations, presentation and discussion of SEDIBUD key test sites, discussions within defined work groups and guided field trip to Kaerkevagge. This workshop will address the key aim of SEDIBUD to discuss Source-to-Sink-Fluxes and Sediment Budgets in Changing Cold Environments. Major emphasis will be given to consequences of climate change, scaling issues and source-to-sink correlations. Central issues will be presentation and discussion of the SEDIFLUX Manual (First Edition), the selection of SEDIBUD key test sites, the discussion and development of further ideas to extend the scientific activities within SEDIBUD in a global framework.(auth)

  16. Concentrations of metals in river sediment and wetland vegetations ...

    African Journals Online (AJOL)

    Levels of metals were determined in river sediment, rice and sugarcane juice from Lake Victoria basin where small-scale gold processing activities are carried out to assess levels of contamination. Concentrations of metals in river sediments were generally high in areas that were closest to gold ore processing sites.

  17. Calculating background levels for ecological risk parameters in toxic harbor sediment

    Science.gov (United States)

    Leadon, C.J.; McDonnell, T.R.; Lear, J.; Barclift, D.

    2007-01-01

    Establishing background levels for biological parameters is necessary in assessing the ecological risks from harbor sediment contaminated with toxic chemicals. For chemicals in sediment, the term contaminated is defined as having concentrations above background and significant human health or ecological risk levels. For biological parameters, a site could be considered contaminated if levels of the parameter are either more or less than the background level, depending on the specific parameter. Biological parameters can include tissue chemical concentrations in ecological receptors, bioassay responses, bioaccumulation levels, and benthic community metrics. Chemical parameters can include sediment concentrations of a variety of potentially toxic chemicals. Indirectly, contaminated harbor sediment can impact shellfish, fish, birds, and marine mammals, and human populations. This paper summarizes the methods used to define background levels for chemical and biological parameters from a survey of ecological risk investigations of marine harbor sediment at California Navy bases. Background levels for regional biological indices used to quantify ecological risks for benthic communities are also described. Generally, background stations are positioned in relatively clean areas exhibiting the same physical and general chemical characteristics as nearby areas with contaminated harbor sediment. The number of background stations and the number of sample replicates per background station depend on the statistical design of the sediment ecological risk investigation, developed through the data quality objective (DQO) process. Biological data from the background stations can be compared to data from a contaminated site by using minimum or maximum background levels or comparative statistics. In Navy ecological risk assessments (ERA's), calculated background levels and appropriate ecological risk screening criteria are used to identify sampling stations and sites with contaminated

  18. The application of backpropagation neural network method to estimate the sediment loads

    Directory of Open Access Journals (Sweden)

    Ari Gunawan Taufik

    2017-01-01

    Full Text Available Nearly all formulations of conventional sediment load estimation method were developed based on a review of laboratory data or data field. This approach is generally limited by local so it is only suitable for a particular river typology. From previous studies, the amount of sediment load tends to be non-linear with respect to the hydraulic parameters and parameter that accompanies sediment. The dominant parameter is turbulence, whereas turbulence flow velocity vector direction of x, y and z. They were affected by water bodies in 3D morphology of the cross section of the vertical and horizontal. This study is conducted to address the non-linear nature of the hydraulic parameter data and sediment parameter against sediment load data by applying the artificial neural network (ANN method. The method used is the backpropagation neural network (BPNN schema. This scheme used for projecting the sediment load from the hydraulic parameter data and sediment parameters that used in the conventional estimation of sediment load. The results showed that the BPNN model performs reasonably well on the conventional calculation, indicated by the stability of correlation coefficient (R and the mean square error (MSE.

  19. Bedform Dimensions and Suspended Sediment Observations in a Mixed Sand-Mud Intertidal Environment

    Science.gov (United States)

    Lichtman, I. D.; Amoudry, L.; Peter, T.; Jaco, B.

    2016-02-01

    Small-scale bedforms, such as ripples, can profoundly modify near-bed hydrodynamics, near-bed sediment transport and resuspension, and benthic-pelagic fluxes. Knowledge of their dimensions is important for a number of applications. Fundamentally different processes can occur depending on the dimensions of ripples: for low and long ripples, the bed remains dynamically flat and diffusive processes dominate sediment entrainment; for steep ripples, flow separation occurs above the ripples creating vortices, which are far more efficient at entraining sediment into the water column. Recent laboratory experiments for mixtures of sand and mud have shown that bedform dimensions decrease with increasing sediment mud content. However, these same experiments also showed that mud is selectively taken into suspension when bedforms are created and migrate on the bed, leaving sandy bedforms. This entrainment process, selectively suspending fine sediment, is referred to as winnowing. To improve our understanding of bedform and entrainment dynamics of mixed sediments, in situ observations were made on intertidal flats in the Dee Estuary, United Kingdom. A suite of instruments were deployed collecting co-located measurements of the near-bed hydrodynamics, waves, small-scale bed morphology and suspended sediment. Three sites were occupied consecutively, over a Spring-Neap cycle, collecting data for different bed compositions, tide levels and wind conditions. Bed samples were taken when the flats became exposed at low water and a sediment trap collected suspended load when inundated. This study will combine these measurements to investigate the interactions between small-scale bed morphology, near-bed hydrodynamics and sediment entrainment. We will examine bedform development in the complex hydrodynamic and wave climate of tidal flats, in relation to standard ripple predictors. We will also relate the variability in small-scale bedforms to variation in hydrodynamic and wave conditions

  20. Application of nanoparticle tracking analysis for characterising the fate of engineered nanoparticles in sediment-water systems.

    Science.gov (United States)

    Luo, Ping; Roca, Alejandro; Tiede, Karen; Privett, Katie; Jiang, Jiachao; Pinkstone, John; Ma, Guibin; Veinot, Jonathan; Boxall, Alisatair

    2018-02-01

    Novel applications of nanotechnology may lead to the release of engineered nanoparticles (ENPs), which result in concerns over their potential environmental hazardous impact. It is essential for the research workers to be able to quantitatively characterise ENPs in the environment and subsequently to assist the risk assessment of the ENPs. This study hence explored the application of nanoparticle tracking system (NTA) to quantitatively describe the behaviour of the ENPs in natural sediment-water systems. The NTA allows the measurement of both particle number concentration (PNC) and particle size distribution (PSD) of the ENPs. The developed NTA method was applied to a range of gold and magnetite ENPs with a selection of surface properties. The results showed that the positively-charged ENPs interacted more strongly with the sediment than neutral and negatively-charged ENPs. It was also found that the citrate coated Au ENPs had a higher distribution percentage (53%) than 11-mercaptoundecanoic acid coated Au ENPs (20%) and citrate coated magnetite ENPs (21%). The principles of the electrostatic interactions between hard (and soft) acids and bases (HSAB) are used to explain such behaviours; the hard base coating (i.e. citrate ions) will interact more strongly with hard acid (i.e. magnetite) than soft acid (i.e. gold). The results indicate that NTA is a complementary method to existing approaches to characterise the fate and behaviour of ENPs in natural sediment. Copyright © 2017. Published by Elsevier B.V.

  1. Development and Application of a Cohesive Sediment Transport Model in Coastal Louisiana

    Science.gov (United States)

    Sorourian, S.; Nistor, I.

    2017-12-01

    The Louisiana coast has suffered from rapid land loss due to the combined effects of increasing the rate of eustatic sea level rise, insufficient riverine sediment input and subsidence. The sediment in this region is dominated by cohesive sediments (up to 80% of clay). This study presents a new model for calculating suspended sediment concentration (SSC) of cohesive sediments. Several new concepts are incorporated into the proposed model, which is capable of estimating the spatial and temporal variation in the concentration of cohesive sediment. First, the model incorporates the effect of electrochemical forces between cohesive sediment particles. Second, the wave friction factor is expressed in terms of the median particle size diameter in order to enhance the accuracy of the estimation of bed shear stress. Third, the erosion rate of cohesive sediments is also expressed in time-dependent form. Simulated SSC profiles are compared with field data collected from Vermilion Bay, Louisiana. The results of the proposed model agree well with the experimental data, as soon as steady state condition is achieved. The results of the new numerical models provide a better estimation of the suspended sediment concentration profile compared to the initial model developed by Mehta and Li, 2003. Among the proposed developments, the formulation of a time-dependent erosion rate shows the most accurate results. Coupling of present model with the Finite-Volume, primitive equation Community Ocean Model (FVCOM) would shed light on the fate of fine-grained sediments in order to increase overall retention and restoration of the Louisiana coastal plain.

  2. The preglacial sediment record of Lake Ladoga, Russia - first results from a seismic survey and sediment coring in 2013

    Science.gov (United States)

    Melles, Martin; Krastel, Sebastian; Fedorov, Grigory; Subetto, Dmitry A.; Savelieva, Larisa A.; Andreev, Andrej; Wagner, Bernd

    2014-05-01

    The new German-Russian project PLOT (Paleolimnological Transect) aims at investigating the Late Quaternary climatic and environmental history along a more than 6000 km long longitudinal transect crossing northern Eurasia. Special emphasis is put on the preglacial history. For this purpose shallow and deep seismic surveys shall be carried out on five lakes, which potentially host preglacial sediment records, followed by sediment coring based on the results of the seismic campaigns. The well-studied Lake El'gygytgyn represents the eastern-most location of the transect and acts as reference site. Within the scope of a pilot phase for the PLOT project, funded by the German Federal Ministry of Education and Research, we were able to investigate Lake Ladoga, which is located close to St. Petersburg at the western end of the transect. Lake Ladoga is the largest lake in Europe, covering an area of almost 18.000 km2. The modern sedimentation as well as the late glacial and Holocene history of the lake were already studied in detail over the past decades. The older, preglacial lake history, however, is only rudimentary known from a core transect drilled in the southern lake in the 1930th. The cores of up to about 60 m length were only briefly described and are not existing any more. The results from these cores, known from unpublished reports only, suggest the existence of marine sediments of presumably Eemian age, representing a time when Lake Lagoga was part of a precursor of the Baltic Sea, which had a connection via Ladoga and Onega Lakes to the White Sea and further to the Arctic Ocean. In late August/early September 2013 we carried out a seismic survey on Lake Ladoga using a Mini-GI-Gun and a 32-channel seismic streamer. In total, 1500 km of seismic profiles were measured, covering most parts of the lake. The seismic lines typically show acoustically well stratified Holocene muds overlaying rather transparent postglacial varves. These sediment successions can reach

  3. Modeling chemical gradients in sediments under losing and gaining flow conditions: The GRADIENT code

    Science.gov (United States)

    Boano, Fulvio; De Falco, Natalie; Arnon, Shai

    2018-02-01

    Interfaces between sediments and water bodies often represent biochemical hotspots for nutrient reactions and are characterized by steep concentration gradients of different reactive solutes. Vertical profiles of these concentrations are routinely collected to obtain information on nutrient dynamics, and simple codes have been developed to analyze these profiles and determine the magnitude and distribution of reaction rates within sediments. However, existing publicly available codes do not consider the potential contribution of water flow in the sediments to nutrient transport, and their applications to field sites with significant water-borne nutrient fluxes may lead to large errors in the estimated reaction rates. To fill this gap, the present work presents GRADIENT, a novel algorithm to evaluate distributions of reaction rates from observed concentration profiles. GRADIENT is a Matlab code that extends a previously published framework to include the role of nutrient advection, and provides robust estimates of reaction rates in sediments with significant water flow. This work discusses the theoretical basis of the method and shows its performance by comparing the results to a series of synthetic data and to laboratory experiments. The results clearly show that in systems with losing or gaining fluxes, the inclusion of such fluxes is critical for estimating local and overall reaction rates in sediments.

  4. Wayne Interim Storage Site annual environmental report for calendar year 1991, Wayne, New Jersey. [Wayne Interim Storage Site

    Energy Technology Data Exchange (ETDEWEB)

    None

    1992-09-01

    This document describes the envirormental monitoring program at the Wayne Interim Storage Site (WISS) and surrounding area, implementation of the program, and monitoring results for 1991. Environmental monitoring of WISS and surrounding area began in 1984 when Congress added the site to the US Department of Energy's (DOE) Formerly Utilized Sites Remedial Action Program (FUSRAP). FUSRAP is a DOE program to decontaminate or otherwise control sites where residual radioactive materials remain from the early years of the nation's atomic energy program or from commercial operations causing conditions that Congress has authorized DOE to remedy. WISS is a National Priorities List site. The environmental monitoring program at WISS includes sampling networks for radon and thoron concentrations in air; external gamma radiation exposure; and radium-226, radium-228, thorium-232, and total uranium concentrations in surface water, sediment, and groundwater. Several nonradiological parameters are also measured in groundwater. Monitoring results are compared with applicable Environmental Protection Agency standards, DOE derived concentration guides, dose limits, and other requirements in DOE orders. Environmental standards are established to protect public health and the environment.

  5. Sediment redistribution and grainsize effects on 230Th-normalized mass accumulation rates and focusing factors in the Panama Basin

    Science.gov (United States)

    Loveley, Matthew R.; Marcantonio, Franco; Lyle, Mitchell; Ibrahim, Rami; Hertzberg, Jennifer E.; Schmidt, Matthew W.

    2017-12-01

    Here, we examine how redistribution of differing grain sizes by sediment focusing processes in Panama Basin sediments affects the use of 230Th as a constant-flux proxy. We study representative sediments of Holocene and Last Glacial Maximum (LGM) time slices from four sediment cores from two different localities close to the ridges that bound the Panama Basin. Each locality contains paired sites that are seismically interpreted to have undergone extremes in sediment redistribution, i.e., focused versus winnowed sites. Both Holocene and LGM samples from sites where winnowing has occurred contain significant amounts (up to 50%) of the 230Th within the >63 μm grain size fraction, which makes up 40-70% of the bulk sediment analyzed. For sites where focusing has occurred, Holocene and LGM samples contain the greatest amounts of 230Th (up to 49%) in the finest grain-sized fraction (winnowed sites. Corrections made using a model by Kretschmer et al. (2010) suggest a maximum change of about 30% in 230Th-derived MARs and focusing factors at focused sites, except for our most focused site which requires an approximate 70% correction in one sample. Our 230Th-corrected 232Th flux results suggest that the boundary between hemipelagically- and pelagically-derived sediments falls between 350 and 600 km from the continental margin.

  6. Field application of a multi-frequency acoustic instrument to monitor sediment for silt erosion study in Pelton turbine in Himalayan region, India

    Science.gov (United States)

    Rai, A. K.; Kumar, A.; Hies, T.; Nguyen, H. H.

    2016-11-01

    High sediment load passing through hydropower components erodes the hydraulic components resulting in loss of efficiency, interruptions in power production and downtime for repair/maintenance, especially in Himalayan regions. The size and concentration of sediment play a major role in silt erosion. The traditional process of collecting samples manually to analyse in laboratory cannot suffice the need of monitoring temporal variation in sediment properties. In this study, a multi-frequency acoustic instrument was applied at desilting chamber to monitor sediment size and concentration entering the turbine. The sediment size and concentration entering the turbine were also measured with manual samples collected twice daily. The samples collected manually were analysed in laboratory with a laser diffraction instrument for size and concentration apart from analysis by drying and filtering methods for concentration. A conductivity probe was used to calculate total dissolved solids, which was further used in results from drying method to calculate suspended solid content of the samples. The acoustic instrument was found to provide sediment concentration values similar to drying and filtering methods. However, no good match was found between mean grain size from the acoustic method with the current status of development and laser diffraction method in the first field application presented here. The future versions of the software and significant sensitivity improvements of the ultrasonic transducers are expected to increase the accuracy in the obtained results. As the instrument is able to capture the concentration and in the future most likely more accurate mean grain size of the suspended sediments, its application for monitoring silt erosion in hydropower plant shall be highly useful.

  7. Selected elements and organic chemicals in streambed sediment in the Salem area, Oregon, 1999

    Science.gov (United States)

    Tanner, Dwight Q.

    2002-09-13

    Analysis of streambed sediments in the Salem, Oregon, area showed anomalously large concentrations of some elements and organic chemicals, indicating contamination from anthropogenic and/or geologic sources. The streambed sediment sample from Clark Creek, an urban basin, had large concentrations of polycyclic aromatic hyrdocarbons (PAHs), organochlorines, cadmium, lead, and zinc. The sample from the East Fork of Pringle Creek, which is a mostly urban basin, had the highest concentrations of DDD, DDE, and DDT compounds. Aldrin was detected in streambed sediment at only one site, the East Fork of Pringle Creek. Ten of the 14 sites sampled had exceedances of the sediment quality guidelines of the Canadian Council of Ministers of the Environment (CCME), and 8 sites had exceedances of guidelines from the Puget Sound Dredged Disposal Analysis (PSDDA) Program.

  8. Impacts of exotic mangrove forests and mangrove deforestation on carbon remineralization and ecosystem functioning in marine sediments

    Science.gov (United States)

    Sweetman, A.K.; Middelburg, J.J.; Berle, A.M.; Bernardino, A.F.; Schander, C.; Demopoulos, A.W.J.; Smith, C.R.

    2010-01-01

    To evaluate how mangrove invasion and removal can modify benthic carbon cycling processes and ecosystem functioning, we used stable-isotopically labelled algae as a deliberate tracer to quantify benthic respiration and C-flow through macrofauna and bacteria in sediments collected from (1) an invasive mangrove forest, (2) deforested mangrove sites 2 and 6 years after removal of above-sediment mangrove biomass, and (3) two mangrove-free, control sites in the Hawaiian coastal zone. Sediment oxygen consumption (SOC) rates were significantly greater in the mangrove and mangrove removal site experiments than in controls and were significantly correlated with total benthic (macrofauna and bacteria) biomass and sedimentary mangrove biomass (SMB). Bacteria dominated short-term C-processing of added microalgal-C and benthic biomass in sediments from the invasive mangrove forest habitat. In contrast, macrofauna were the most important agents in the short-term processing of microalgal-C in sediments from the mangrove removal and control sites. Mean faunal abundance and short term C-uptake rates in sediments from both removal sites were significantly higher than in control cores, which collectively suggest that community structure and short-term C-cycling dynamics in habitats where mangroves have been cleared can remain fundamentally different from un-invaded mudflat sediments for at least 6-yrs following above-sediment mangrove removal. In summary, invasion by mangroves can lead to large shifts in benthic ecosystem function, with sediment metabolism, benthic community structure and short-term C-remineralization dynamics being affected for years following invader removal. ?? 2010 Author(s).

  9. Spatially resolved data on sediment transport: 1) field application examining fluorescent soil particle movement from tillage

    Science.gov (United States)

    Quinton, John; Hardy, Robert; Pates, Jacqueline; James, Michael

    2017-04-01

    Understanding where sediment originates from and where it travels to, in what quantities and at which rate is at the heart of many questions surrounding sediment transport. Progress towards unravelling these questions and deepening our understanding has come from a wide range of approaches, including laboratory and field experiments conducted at a variety of scales. In seeking to understand the connectivity of sources and sinks of sediment scientists have spent considerable energy in developing tracing technologies. These have included numerous studies that have relied on the chemical properties of the soil and sediment to establish source-sink connectivity, and the use of 137Ceasium, from radioactive fall-out, to map sediment redistribution. More recently there has been an upsurge in interest in the use of artificially applied soil tracers, including rare earth element oxides and magnetic minerals. However all these tracing methods have a significant drawback: they rely on the collection of samples to assess their concentration. This means that their spatial distribution cannot easily be established in situ and that the environment that is being studied is damaged by the sampling process; nor can data be collected in real time which allows a dynamic understanding of erosion and transport processes to be developed. Here we report on the field application of a fluorescent sand sized tracer at the hillslope scale during a tillage erosion experiment. Here we trialled both intensity based and particle counting methodologies for tracer enumeration. After simulating seven years of tillage on a hillslope we were able to precisely determine the distribution of the fluorescent tracer and also its incorporation and distribution within the soil profile. Single grains of tracer could be found over 35 m from the insertion point. In a second abstract we report on an application that combines novel fluorescent videography techniques with custom image processing to trace the

  10. Assessment of the role of bottomland hardwoods in sediment and erosion control

    Science.gov (United States)

    Molinas, A.; Auble, Gregor T.; Segelquist, C.A.; Ischinger, Lee S.

    1988-01-01

    Drainage and clearing of bottomland hardwoods have long been recognized by the U.S. Environmental Protection Agency (EPA) and the U.S. Fish and Wildlife Service (Service) as important impacts of Federal water projects in the lower Mississippi River Valley. More recently, the water quality impacts of such projects (e.g., increases in sediments, nutrients, and pesticides) have also become of concern. In 1984, in an effort to better define problems concerning wetland losses and water degradation, EPA initiated a cooperative project with the Western Energy and Land Use Team (now the National Ecology Research Center) of the Service. Three phases of the project were identified: 1. To collect existing literature and data; 2. To select, develop, and test the utility of methods to quantify the relationships between land use, cover types, soils, hydrology, and water quality (as represented by sediment); and 3. To apply selected methodologies to several sites within the Yazoo Basin of Mississippi to determine the, potential effectiveness of various management alternatives to reduce sediment yield, increase sediment deposition, and improve water quality. Methods development focused on linking a simulation of water and sediment movement to a computerized geographic information system. We had several objectives for the resulting model. We desired that it should: 1. Estimate the importance of bottomland and hardwoods as a cover type that performs the functions of erosion and sediment control, 2. Simulate effects of proportions of ' various cover types and their specific spatial configurations, 3. Be applicable to moderately large spatial areas with minimal site-specific calibration, 4. Simulate spatial patterns of sediment loss-gain over time, and 5. Represent both sediment detachment and transport. While it was recognized that impacts and management alternatives could be sorted roughly into landscape measures and channel measures, the decision was made to focus study efforts

  11. Quantifying tidally driven benthic oxygen exchange across permeable sediments

    DEFF Research Database (Denmark)

    McGinnis, Daniel F.; Sommer, Stefan; Lorke, Andreas

    2014-01-01

    Continental shelves are predominately (approximate to 70%) covered with permeable, sandy sediments. While identified as critical sites for intense oxygen, carbon, and nutrient turnover, constituent exchange across permeable sediments remains poorly quantified. The central North Sea largely consists...... of permeable sediments and has been identified as increasingly at risk for developing hypoxia. Therefore, we investigate the benthic O-2 exchange across the permeable North Sea sediments using a combination of in situ microprofiles, a benthic chamber, and aquatic eddy correlation. Tidal bottom currents drive...... the variable sediment O-2 penetration depth (from approximate to 3 to 8 mm) and the concurrent turbulence-driven 25-fold variation in the benthic sediment O-2 uptake. The O-2 flux and variability were reproduced using a simple 1-D model linking the benthic turbulence to the sediment pore water exchange...

  12. The Influence of Social Network Sites on the Job Application Process

    DEFF Research Database (Denmark)

    Ben Allouch, Somaya; Kotamraju, Nalini Panchita

    2011-01-01

    The popularity of social network sites has given rise to concerns about the amount and nature of information that people disclose on them. While the media has publicized several high-profile instances of people losing their jobs because they had disclosed inappropriate job-related, empirical......, but when tested experimentally, the results show that recruiters do rely more on information derived from others than on self-reported information. This research confirms the popular suspicion that social network sites influence job applicants’ career opportunities, but also goes further to demonstrate...... research about the use of social network sites by job recruiters is almost non-existing. Social network sites are nowadays tools for recruiters to screen job applicants during the job application procedure. This study examined what specific information on social network sites recruiters use to form...

  13. Biosolids, Soil, Crop, Ground-Water, and Streambed-Sediment Data for A Biosolids-Application Area Near Deer Trail, Colorado, 2001

    National Research Council Canada - National Science Library

    Yager, Tracy J; Smith, David B; Crock, James G

    2004-01-01

    .... Monitoring components were biosolids, soils, crops, ground water, and streambed sediment. The monitoring program addresses concerns from the public about chemical effects from applications of biosolids to farmland in the Deer Trail, Colorado, area...

  14. Stream sediment sampling and analysis. Final report

    International Nuclear Information System (INIS)

    Means, J.L.; Voris, P.V.; Headington, G.L.

    1986-04-01

    The objectives were to sample and analyze sediments from upstream and downstream locations (relative to the Goodyear Atomic plant site) of three streams for selected pollutants. The three streams sampled were the Scioto River, Big Beaver Creek, and Big Run Creek. Sediment samples were analyzed for EPA's 129 priority pollutants (Clean Water Act) as well as isotopic uranium ( 234 U, 235 U, and 238 U) and technetium-99

  15. Biota-sediment accumulation factors for radionuclides and sediment associated biota of the Ottawa River

    Energy Technology Data Exchange (ETDEWEB)

    Rowan, D.; Silke, R.; Carr, J., E-mail: rowand@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2013-12-15

    As Ottawa River contamination is historical and resides in sediment, ecological risk and trophic transfer depend on linkages between sediment and biota. One of the ways in which this linkage is quantified is through the use of the biota sediment accumulation factor (BSAF). In this study, we present the first field estimates of BSAF for a number of radionuclides. The strongest and most consistent BSAFs were those for {sup 137}Cs in deposit feeding taxa, suggesting that sediment concentrations rather than dissolved concentrations drive uptake. For crayfish and unionid bivalves that do not feed on sediment, biota radionuclide concentrations were not related to sediment concentrations, but rather reflected concentrations in water. BSAFs would not be appropriate for these non-deposit feeding biota. BSAFs for {sup 137}Cs were not significantly different among deposit feeding taxa, suggesting similar processes for ingestion, assimilation and elimination. These data also show that the concentration factor approach used for guidance would have led to spurious results in this study for deposit feeding benthic invertebrates. Concentrations of {sup 137}Cs in Hexagenia downstream of the CRL process outfall range by about 2-orders of magnitude, in comparison to relatively uniform water concentrations. The concentration factor approach would have predicted a single value downstream of CRL, underestimating exposure to Hexagenia by almost 2-orders of magnitude at sites close to the CRL process outfall. (author)

  16. Structural practices for controlling sediment transport from erosion

    Science.gov (United States)

    Gabriels, Donald; Verbist, Koen; Van de Linden, Bruno

    2013-04-01

    Erosion on agricultural fields in the hilly regions of Flanders, Belgium has been recognized as an important economical and ecological problem that requires effective control measures. This has led to the implementation of on-site and off-site measures such as reduced tillage and the installation of grass buffers trips, and dams made of vegetative materials. Dams made out of coir (coconut) and wood chips were evaluated on three different levels of complexity. Under laboratory conditions, one meter long dams were submitted to two different discharges and three sediment concentrations under two different slopes, to assess the sediment delivery ratios under variable conditions. At the field scale, discharge and sediment concentrations were monitored under natural rainfall conditions on six 3 m wide plots, of which three were equipped with coir dams, while the other three served as control plots. The same plots were also used for rainfall simulations, which allowed controlling sediment delivery boundary conditions more precisely. Results show a clear advantage of these dams to reduce discharge by minimum 49% under both field and laboratory conditions. Sediment delivery ratios (SDR) were very small under laboratory and field rainfall simulations (4-9% and 2% respectively), while larger SDRs were observed under natural conditions (43%), probably due to the small sediment concentrations (1-5 g l-1) observed and as such a larger influence of boundary effects. Also a clear enrichment of larger sand particles (+167%) could be observed behind the dams, showing a significant selective filtering effect.

  17. Understanding Sediment Sources, Pathways, and Sinks in Regional Sediment Management: Application of Wash Load and Bed-Material Load Concept

    National Research Council Canada - National Science Library

    Biedenham, David S; Hubbard, Lisa C; Thome, Colin R; Watson, Chester C

    2006-01-01

    ... through the fluvial system for sediments derived from various bed, bank, gully, and catchment sources thereby providing a reliable analytical foundation for effective regional sediment management...

  18. Nitrate bioreduction in redox-variable low permeability sediments

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Sen [China University of Geosciences, Wuhan 430074 (China); Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Liu, Yuanyuan [Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Liu, Chongxuan, E-mail: chongxuan.liu@pnnl.gov [China University of Geosciences, Wuhan 430074 (China); Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Shi, Liang; Shang, Jianying [Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Shan, Huimei [China University of Geosciences, Wuhan 430074 (China); Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Zachara, John; Fredrickson, Jim; Kennedy, David; Resch, Charles T.; Thompson, Christopher; Fansler, Sarah [Pacific Northwest National Laboratory, Richland, WA 99354 (United States)

    2016-01-01

    Low permeability zone (LPZ) can play an important role as a sink or secondary source in contaminant transport in groundwater system. This study investigated the rate and end product of nitrate bioreduction in LPZ sediments. The sediments were from the U.S. Department of Energy's Hanford Site, where nitrate is a groundwater contaminant as a by-product of radionuclide waste discharges. The LPZ at the Hanford site consists of two layers with an oxidized layer on top and reduced layer below. The oxidized layer is directly in contact with the overlying contaminated aquifer, while the reduced layer is in contact with an uncontaminated aquifer below. The experimental results showed that nitrate bioreduction rate and end-product differed significantly in the sediments. The bioreduction rate in the oxidized sediment was significantly faster than that in the reduced one. A significant amount of N{sub 2}O was accumulated in the reduced sediment; while in the oxidized sediment, N{sub 2}O was further reduced to N{sub 2}. RT-PCR analysis revealed that nosZ, the gene that codes for N{sub 2}O reductase, was below detection limit in the reduced sediment. Batch experiments and kinetic modeling were performed to provide insights into the role of organic carbon bioavailability, biomass growth, and competition between nitrate and its reducing products for electrons from electron donors. The results revealed that it is important to consider sediment redox conditions and functional genes in understanding and modeling nitrate bioreduction in subsurface sediments. The results also implied that LPZ sediments can be important sink of nitrate and a potential secondary source of N{sub 2}O as a nitrate bioreduction product in groundwater. - Highlights: • Low permeability zones (LPZ) can microbially remove nitrate in groundwater. • The rate and end product of nitrate bioreduction vary within LPZ. • Greenhouse gas N{sub 2}O can be the end product of nitrate bioreduction in LPZ.

  19. Shifting sources and transport paths for the late Quaternary Escanaba Trough sediment fill (northeast Pacific)

    Science.gov (United States)

    Zuffa, G.G.; De Rosa, R.; Normark, W.R.

    1997-01-01

    Escanaba Trough, which forms the southernmost part of the axial valley of the actively spreading Gorda Ridge, is filled with several hundred meters of sediment of presumed late Quaternary age. Surficial sediment samples from gravity cores, deeper samples (as much as 390 m) from Site 35 of the Deep Sea Drilling Program (Leg 5), and the acoustic character of the sediment fill observed on seismic-reflection profiles indicate that much of the sediment fill is of turbidite origin. Gross composition and heavy- mineral analyses of sand samples show that two distinct petrofacies comprise the sediment fill. The lower part of the fill was derived primarily from the Klamath River source of northern California while the younger fill, including the surficial sand beds, are from the Columbia River drainage much farther north. The Escanaba Trough sediment provides an opportunity to evaluate concepts for paleogeographic and paleotectonic reconstructions that are based on facies analysis and compositional and textural data for the volcanic components because both intrabasinal and extrabasinal sources are present as well as coeval (neovolcanic) and non coeval (paleovolcanic) sourcre This study of a modern basin shows, that although the sediment sources could be identified, it was useful to have some knowledge of the sediment pathway(s), the effects of diagenesis, and the possible effects of sediment sorting as a result of long transport distances from the source area for some components. Application of these same techniques to ancient deposits without benefit of the additional parameters will face limitations.

  20. Limited mobility of dioxins near San Jacinto super fund site (waste pit) in the Houston Ship Channel, Texas due to strong sediment sorption.

    Science.gov (United States)

    Louchouarn, Patrick; Seward, Shaya M; Cornelissen, Gerard; Arp, Hans Peter H; Yeager, Kevin M; Brinkmeyer, Robin; Santschi, Peter H

    2018-02-20

    Sediments from a waste pit in Houston Ship Channel (HSC) were characterized using a number of molecular markers of natural organic matter fractions (e.g., pyrogenic carbon residues, PAHs, lignins), in addition to dioxins, in order to test the hypothesis that the dispersal and mobility of dioxins from the waste pit in the San Jacinto River is minimal. Station SG-6, sampled at the site of the submerged waste pit, had the highest dioxin/furan concentrations reported for the Houston Ship Channel/Galveston Bay (HSC/GB) system (10,000-46,000 pg/g), which translated into some of the highest reported World Health Organization Toxic Equivalents (TEQs: 2000-11,000 pg/g) in HSC sediments. Using a multi-tracer approach, this study confirmed our hypothesis that sludges from chlorinated pulps are a very likely source of dioxins/furans to this pit. However, this material also contained large quantities of additional hydrophobic organic contaminants (PAHs) and pyrogenic markers (soot-BC, levoglucosan), pointing to the co-occurrence of petroleum hydrocarbons and combustion byproducts. Comparison of dioxin/furan signatures in the waste pit with those from sediments of the HSC and a control site suggests that the remobilization of contaminated particles did not occur beyond the close vicinity of the pit itself. The dioxins/furans in sediments outside the waste pit within the HSC are rather from other diffuse inputs, entering the sedimentary environment through the air and water, and which are comprised of a mixture of industrial and municipal sources. Fingerprinting of waste pit dioxins indicates that their composition is typical of pulp and paper sources. Measured pore water concentrations were 1 order of magnitude lower than estimated values, calculated from a multiphase sorption model, indicating low mobility of dioxins within the waste pit. This is likely accomplished by co-occurring and strong sorbing pyrogenic and petrogenic residues in the waste pit, which tend to keep

  1. 77 FR 74457 - Foreign-Trade Zone 75-Phoenix, Arizona Application for Expansion (New Magnet Site) Under...

    Science.gov (United States)

    2012-12-14

    ..., Arizona Application for Expansion (New Magnet Site) Under Alternative Site Framework An application has...) adopted by the Board (15 CFR 400.2(c)) to include a new magnet site in Phoenix, Arizona. The application... zone project includes the following magnet sites: Site 1 (338 acres)--within the 550-acre Phoenix Sky...

  2. Assessment of the governance system for the management of the East Sea-Jung dumping site, Korea through analysis of heavy metal concentrations in bottom sediments

    Science.gov (United States)

    Song, Ki-Hoon; Choi, Ki-Young; Kim, Chang-Joon; Kim, Young-Il; Chung, Chang-Soo

    2015-12-01

    As with many countries, the Korea government has made a variety of efforts to meet the precautionary principle under the London Convention and Protocol acceded in 1994 and 2009. However, new strategies for the suitable marine dumping of waste materials have since been developed. In this study, the distribution and contamination of heavy metals including Al, Fe, Mn, Li, Co, Cr, Ni, Cu, Zn, As, Cd, Pb and Hg in bottom sediments were analyzed and compared to various criteria in order to evaluate the effectiveness of the management of the East Sea-Jung (ES-Jung) dumping site by the Korea government. The results indicate that the average metal concentrations were significantly lower than Effects Range Low (ERL) values, and generally similar to or lower than the Threshold Effect Levels (TEL) from the Sediment Quality Guidelinces (SQGs). According to analyses of various metal contamination indexes (Enrichment Factor: EF, Pollution Load Index: PLI and the Index of Geoaccumulation: Igeo), most areas were found to be uncontaminated by heavy metals with the exception of several moderately contaminated stations (ESJ 33, 54, 64 and ESJR 20). Heavy metal concentrations in areas grouped as G1, G2, DMDA, N-Ref and S-Ref which showed similar characteristics between 2007-2013 and 2014, were compared. Unexpectedly, most concentrations in the northern reference area (N-Ref) were much higher than those in the actual dumping areas (G1 and G2), may be due to the influences from nearby cities to the west of the ES-Jung site, rather than from the dumping site itself. Additionally, heavy metal concentrations in the dredged material dumping area (DMDA) were found to be low although they have slightly increased over time and those in the southern reference area (S-Ref) were found to have gradually decreased with year. The concentrations of most metals in the East Sea-Jung dumping site were similar to or less than those in the Earth's crust and approximately the same as those in continental

  3. Effects of clay minerals and organic matter in formulated sediments on the bioavailability of sediment-associated uranium to the freshwater midge, Chironomus dilutus

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Sarah E., E-mail: sarah.crawford@usask.ca [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3 (Canada); Liber, Karsten, E-mail: karsten.liber@usask.ca [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3 (Canada); School of Environment and Sustainability, 117 Science Place, University of Saskatchewan, Saskatoon, SK S7N 5C8 (Canada); Institute of Loess Plateau, 92 Wucheng Road, Shanxi University, Taiyuan, Shanxi 030006 (China)

    2015-11-01

    It is well established that bioavailability influences metal toxicity in aquatic ecosystems. However, the factors and mechanisms that influence uranium (U) bioavailability and toxicity in sediment have not been thoroughly evaluated, despite evidence that suggests different sediment components can influence the sorption and interaction of some metals. Given that dissolved U is generally accepted as being the primary bioavailable fraction of U, it is hypothesized that adsorption and interaction of U with different sediment components will influence the bioavailability of U in sediment. We investigated the effects of key sediment physicochemical properties on the bioavailability of U to a model freshwater benthic invertebrate, Chironomus dilutus. Several 10-day spiked sediment bioaccumulation experiments were performed, exposing C. dilutus larvae to a variety of formulated sediments spiked with different concentrations of U (5, 50 and/or 200 mg U/kg d.w.). Mean accumulation of U in C. dilutus larvae decreased significantly from 1195 to 10 mg U/kg d.w. as kaolin clay content increased from 0% to 60% in sediment spiked with 50 mg U/kg d.w. Similarly, higher organic matter content also resulted in a significant reduction of U bioaccumulation in C. dilutus larvae, indicating a reduction in U bioavailability. Concentrations of U in both the overlying water and sediment pore water displayed a strong positive relationship to U bioaccumulation in C. dilutus larvae (r{sup 2} = 0.77, p < 0.001 and r{sup 2} = 0.57, p < 0.001, respectively) for all experiments, while total U concentrations in the sediment had a poor relationship to U bioaccumulation (r{sup 2} = 0.10, p = 0.028). Results from this research confirm that sediment clay and organic matter content play a significant role in altering U bioavailability, which is important in informing risk assessments of U contaminated sites and in the development of site-specific sediment quality guidelines for U. - Highlights: • We

  4. Spatial distributions and temporal trends in polybrominated diphenyl ethers in Detroit River suspended sediments.

    Science.gov (United States)

    Marvin, Chris; Waltho, Jasmine; Jia, Julia; Burniston, Debbie

    2013-05-01

    Suspended sediments from the Detroit River were collected using sediment traps at sites ranging from western Lake Erie to southern Lake St. Clair to assess spatial distributions and temporal trends of polybrominated diphenyl ethers (PBDEs). The distribution of PBDEs in suspended sediments in the Detroit River appeared influenced by shoreline-based contemporary urban and industrial activities, which stood in contrast to PCBs that were associated with areas of historic industrial activity. Temporal trend data indicate that total PBDE concentrations decreased in the period after 2000 in response to cessation of production of the penta- and octa BDE formulations. Concentrations of total PBDEs ranged from roughly 7 ng g(-1) (4 ng g(-1) BDE 209) in southern Lake St. Clair to several hundred ng g(-1) (60-180 ng g(-1) BDE 209) in the lower reaches of the Detroit River. The widespread occurrence of PBDEs in Detroit River suspended sediments suggests that large urban areas can act as diffuse sources of these chemicals that are used in modern industrial applications and consumer products. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  5. Organochlorine compounds in streambed sediment and in biological tissue from streams and their relations to land use, central Arizona

    Science.gov (United States)

    Gebler, Joseph B.

    2000-01-01

    Streambed-sediment samples from 13 sites and biological-tissue samples from 11 sites in the Gila River Basin in central Arizona were analyzed for 32 organochlorine compounds in streambed sediment and 28 compounds in biological tissue during 1996 as part of the U.S. Geological Survey's National Water-Quality Assessment program. The objectives of the study were to determine the occurrence and distribution of organochlorine compounds and their relation to land use. Sampling sites were categorized on the basis of major land uses in the basin or the source of water in the stream. Because land uses were mixed or had changed over time, some land-use categories were combined. Sites were categorized as forest/rangeland (6), forest/urban (1), urban (4), or agricultural/urban (2). Thirteen organochlorine compounds were detected in streambed-sediment samples, and 10 were detected in tissue samples. The number of compounds found in streambed-sediment samples from individual sites ranged from 0 to 10, and the range for individual tissue samples was 0 to 7. Comparison of the number of detections in streambed-sediment samples to the number of detections in tissue samples from particular sites where both were sampled yielded five instances where more compounds were detected in streambed sediment, six instances where more compounds were detected in tissue, and five instances where the number of detections in streambed sediment and tissue were equal. The frequency of detection of particular compounds for sites where both streambed sediment and tissue were sampled resulted in five compounds being detected more frequently in streambed sediment, five more frequently in tissue, and three compounds that were equally frequent in streambed sediment and in tissue. Few contaminants were detected in samples from the forest/rangeland sites; greater numbers of compounds were detected at the urban sites and at the forest/urban site. The greatest number of compounds and the highest concentrations

  6. A site-specific slurry application technique on grassland and on arable crops.

    Science.gov (United States)

    Schellberg, Jürgen; Lock, Reiner

    2009-01-01

    There is evidence that unequal slurry application on agricultural land contributes to N losses to the environment. Heterogeneity within fields demands adequate response by means of variable rate application. A technique is presented which allows site-specific application of slurry on grassland and arable land based on pre-defined application maps. The system contains a valve controlling flow rate by an on-board PC. During operation, flow rate is measured and scaled against set point values given in the application map together with the geographic position of the site. The systems worked sufficiently precise at a flow rate between 0 and 25 l s(-1) and an offset of actual slurry flow from set point values between 0.33 and 0.67 l s(-1). Long-term experimentation is required to test if site-specific application de facto reduces N surplus within fields and so significantly contributes to the unloading of N in agricultural areas.

  7. Contrasts in Sediment Delivery and Dispersal from River Mouth to Accumulation Zones in High Sediment Load Systems: Fly River, Papua New Guinea and Waipaoa River, New Zealand

    Science.gov (United States)

    Ogston, A. S.; Walsh, J. P.; Hale, R. P.

    2011-12-01

    The relationships between sediment-transport processes, short-term sedimentary deposition, subsequent burial, and long-term accumulation are critical to understanding the morphological development of the continental margin. This study focuses on processes involved in formation and evolution of the clinoform in the Gulf of Papua, Papua New Guinea in which much of the riverine sediment accumulates, and comparison to those processes active off the Waipaoa River, New Zealand that form mid-shelf deposits and export sediment to the slope. In tidally dominated deltas, sediment discharged from the river sources must transit through an estuarine region located within the distributary channels, where particle pathways can undergo significant transformations. Within the distributaries of the Fly River tidally dominated delta, near-bed fluid-mud concentrations were observed at the estuarine turbidity maximum and sediment delivery to the nearshore was controlled by the morphology and gradient of the distributary. El Niño results in anonymously low flow and sediment discharge conditions, which limits transport of sediment from the distributaries to the nearshore zone of temporary storage. Because the sediment stored nearshore feeds the prograding clinoform, this perturbation propagates throughout the dispersal system. In wave-dominated regions, transport mechanisms actively move sediment away from the river source, separating the site of deposition and accumulation from the river mouth. River-flood and storm-wave events each create discrete deposits on the Waipaoa River shelf and data has been collected to determine their form, distribution, and relationship to factors such as flood magnitude or wave energy. In this case, transport pathways appear to be influenced by structurally controlled shelf bathymetry. In both cases, the combined fluvial and marine processes can initiate and maintain gravity-driven density flows, and although their triggers and controls differ vastly

  8. Sediment quality in the north coastal basin of Massachusetts, 2003

    Science.gov (United States)

    Breault, Robert F.; Ashman, Mary S.; Heath, Douglas

    2004-01-01

    The U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, completed a reconnaissance-level study of bottom-sediment quality in selected lakes, rivers, and estuaries in the North Coastal Basin of Massachusetts. Bottom-sediment grab samples were collected from 20 sites in the North River, Lake Quannapowitt, Saugus River, Mill River, Shute Brook, Sea Plane Basin, Pines River, and Bear Creek. The samples were tested for various types of potentially harmful contaminants? including 33 elements, 17 polyaromatic hydrocarbons (PAHs), 22 organochlorine pesticides, and 7 polychlorinated biphenyl (PCB) mixtures (Aroclors)?to benthic organisms (bottom-dwelling) and humans. The results were compared among sampling sites, to background concentrations, and to concen-trations measured in other urban rivers, and sediment-quality guidelines were used to predict toxicity at the sampling sites to benthic organisms and humans. Because there are no standards for human toxicity for aquatic sediment, standards for contaminated upland soil were used. Contaminant concentrations measured in sediment collected from the North Coastal Basin generally were equal to or greater than concentrations in sediment from uncontaminated rivers throughout New England. Contaminants in North Coastal Basin sediment with elevated concentrations (above back-ground levels) included arsenic, chromium, copper, lead, nickel, and zinc, some of the PAHs, dichlorodiphenyltrichloro-ethane (DDT) and its metabolites, and dieldrin. No PCBs were measured above the detection limits. Measured concentrations of arsenic, chromium, and lead were also generally greater than those measured in other urban rivers throughout the conter-minous United States. With one exception (arsenic), local con-centrations measured in sediment samples collected from the North Coastal Basin were lower than concentrations measured in sediment collected from two of three urban rivers draining to Boston

  9. Temporal shifts in reef lagoon sediment composition, Discovery Bay, Jamaica

    Science.gov (United States)

    Perry, Christopher T.; Taylor, Kevin G.; Machent, Philip G.

    2006-03-01

    Discovery Bay, north Jamaica, forms a large (1.5 km wide), deep (up to 56 m) embayment that acts as a sink for reef-derived and lagoonal carbonate sediments. Since the mid-1960s, the bay has also provided a sink for inputs of bauxite sediment that are spilled during loading at a boat terminal constructed within Discovery Bay. Bauxite has accumulated across much of the southern section of the bay with surficial sediments presently composed of up to 35 weight% non-carbonate. Cores recovered from sites on the western side of the bay provide a stratigraphic record of this history of bauxite contamination across water depths from 5 to 25 m. The bauxite-influenced upper sediment horizons are clearly visible in each core from the distinctive red-brown colouration of the sediment. These sediments are composed of approximately 10% non-carbonate (bauxite) and have Fe contents of around 2-3000 μg/g (up to 7000 μg/g). The thickness of this upper bauxite-contaminated sequence increases down transect (approximately 18 cm in the shallowest core, to around 47 cm in the deepest core), and in each core overlies a sequence of 'clean' lagoon carbonates. These typically are poorly sorted carbonate sands with variable amounts of coral rubble. Down-core data on CaCO 3 and Fe content provide a chemical record of decreasing sediment contamination with depth, with the lower 'clean' carbonates composed of only around 2% non-carbonate and coral, mollusc, Amphiroa and Halimeda in the clean lagoon sands, to assemblages dominated by Halimeda and Amphiroa within the surficial sediments. At the deeper sites, no major down-core shifts in sediment constituents occur. These sites thus record a rather complex history of changes in sediment composition and chemistry. Clear shifts in chemistry and stratigraphy occur in all the cores and reflect progressive bauxite contamination in the near-surface horizons. These inputs, however, do not appear to have directly affected carbonate production, since the

  10. The effects of clam fishing on the properties of surface sediments in the lagoon of Venice, Italy

    Directory of Open Access Journals (Sweden)

    R. J. Aspen

    2004-01-01

    Full Text Available Harvesting of clams(Tapes philippinarum has important socio-economic and environmental implications for the Venice lagoon area, Italy. Clam harvesting disrupts the structure of benthic communities but the effects upon sediment stability and surface structure remain unclear. The effect of clam fishing on the sediment properties of the lagoon bed was investigated at two different sites, a heavily fished site (San Angelo and an infrequently fished site (San Giaccomo. Both sites were assessed for immediate impacts of fishing, using indicators of biogenic sediment stabilisation. Samples were taken at three points along three 100 m linear transects at each site prior to and post fishing. Paired samples were also taken parallel to each transect at a distance of 5m, to allow for temporal variation. Sediment stability, measured with a cohesive strength meter (CSM, was significantly higher at the less impacted site (F1,34 = 6.23, p a (chl a, colloidal-S carbohydrate and dry bulk density were observed on the transect after fishing but not adjacent to the fishing path. At the heavily impacted site, clam fishing by trawling had, in general, no significant effect on the biological and physical properties (although chl a did decrease significantly after fishing. The lack of a significant impact from fishing at the impacted site was attributed to the higher frequency of fishing occurring in this area. Hence, frequent fishing of the lagoon prevents establishment of biotic communities, preventing biostabilisation and thus reduces the stability of the surface sediment. Keywords: clam harvesting, erosion threshold, microphytobenthos, sediment, stability

  11. The application of passive sampler (DGT technology for improved understanding of metal behaviour at a marine disposal site

    Directory of Open Access Journals (Sweden)

    Parker R.

    2013-04-01

    Full Text Available Metal behaviour and availability at a contaminated dredge material disposal site within UK waters has been investigated using Diffusive Gradient in Thin films (DGT passive sampling technology. Three stations representing contrasting history and presence of maintenance dredge disposal, including a control station outside the disposal site, have been studied and depth profiles of fluxes of different metals (Fe, Mn, Pb, Cu, Cd, Cr, Ni, Zn to the binding gel (Chelex 100 have been derived. Higher flux rates and shallower mobilisation of metals (Mn and Fe to the binding gel were observed at the disposal stations compared to the control station. Here we describe metal mobilization at different depths, linking the remobilization of Fe2+ and Mn2+ to the sediment (resupply of other heavy metals of interest with a focus on Cd, Ni and Pb and as they are on the Water Framework Directive (WFD list of priority substances and OSPAR list of priority pollutants. Results showed that Cd, Pb and Ni exhibited signs of resupply at the sediment-water interface (SWI. There was a potential increased mobilisation and source to the water column of Pb and Ni at the disposal site stations, but there was no Cd source, despite higher total loadings. This information has the potential to improve our current understanding of metal cycles at disposal sites. This work can be used as an indication of likely metal bioavailability and also assist in determining whether the sites act as sources or sinks of heavy metals. This information could assist disposal site monitoring and dredge material licensing.

  12. Principles and Approaches for Numerical Modelling of Sediment Transport in Sewers

    DEFF Research Database (Denmark)

    Mark, Ole; Appelgren, Cecilia; Larsen, Torben

    1995-01-01

    A study has been carried out with the objectives of describing the effect of sediment deposits on the hydraulic capacity of sewer systems and to investigate the sediment transport in sewer systems. A result of the study is a mathematical model MOUSE ST which describes sediment transport in sewers....... This paper discusses the applicability and the limitations of various modelling approaches and sediment transport formulations in in MOUSE ST. Further, the paper presents a simple application of MOUSE ST to the Rya catchment in Gothenburg, Sweden....

  13. Soil an-d nutrient loss following site preparation burning

    Science.gov (United States)

    E.A. Carter; J.P. Field; K.W. Farrish

    2000-01-01

    Sediment loss and nutrient cpncentrations in runoff were evaluated to determine the effects of site preparation burning on a recently harvested loblolly pine (Pinur taeda L.) site in east Texas. Sediment and nutrient losses prior to treatment were approximately the same from control plots and pretreatment burn plots. Nutrient analysis of runoff samples indicated that...

  14. Compilation, quality control, analysis, and summary of discrete suspended-sediment and ancillary data in the United States, 1901-2010

    Science.gov (United States)

    Lee, Casey J.; Glysson, G. Douglas

    2013-01-01

    Human-induced and natural changes to the transport of sediment and sediment-associated constituents can degrade aquatic ecosystems and limit human uses of streams and rivers. The lack of a dedicated, easily accessible, quality-controlled database of sediment and ancillary data has made it difficult to identify sediment-related water-quality impairments and has limited understanding of how human actions affect suspended-sediment concentrations and transport. The purpose of this report is to describe the creation of a quality-controlled U.S. Geological Survey suspended-sediment database, provide guidance for its use, and summarize characteristics of suspended-sediment data through 2010. The database is provided as an online application at http://cida.usgs.gov/sediment to allow users to view, filter, and retrieve available suspended-sediment and ancillary data. A data recovery, filtration, and quality-control process was performed to expand the availability, representativeness, and utility of existing suspended-sediment data collected by the U.S. Geological Survey in the United States before January 1, 2011. Information on streamflow condition, sediment grain size, and upstream landscape condition were matched to sediment data and sediment-sampling sites to place data in context with factors that may influence sediment transport. Suspended-sediment and selected ancillary data are presented from across the United States with respect to time, streamflow, and landscape condition. Examples of potential uses of this database for identifying sediment-related impairments, assessing trends, and designing new data collection activities are provided. This report and database can support local and national-level decision making, project planning, and data mining activities related to the transport of suspended-sediment and sediment-associated constituents.

  15. Marine chemistry and tracer applications of radiocaesium

    International Nuclear Information System (INIS)

    McKay, W.A.

    1983-03-01

    The general aims of this project were to study the marine chemistry of Windscale-derived radiocaesium and to continue previous research at Glasgow University on its tracer application in Scottish waters and sediments. It was found that a considerable percentage of sediment-associated 137 Cs (approximately 12 to 50%) may be contained by carbonate, oxide and organic coatings which appear to be relatively stable under a wide range of redox conditions. Whilst the partitioning of 137 Cs is related to the concentration of these oxides, organics and, to a much lesser extent, carbonates, their function is predominantly to prevent 137 Cs release from clay mineral exchange sites. 137 Cs activities per unit sediment weight were highest in the clay fraction with its uptake by coarse sediments appearing to be controlled by clay minerals coatings formed in the marine environment and cemented partly by oxides and organics. Though the sites sampled (Clyde Sea Area (C.S.A.) and L. Etive) encompassed a wide range of sediment types, the range of estimated 137 Cs distribution coefficients (K D ) was relatively small (360 to 890). Coatings may thus have more influence on K d s in the coastal marine environment than particle size distributions. Apparent concentration factors (C F s) of X325, X2800 and X1910 were determined for the associated carbonate, oxide and organic coatings, for a site off Greenock. Use of 'dry' sediments appeared to produce considerably overestimated values for the degree of 137 Cs fixation. Thus 'wet' sediments were used in these studies. Over the 1978-1981 period, approximately 35% of Windscale output passed through the C.S.A., diluted 26 times during transit. An estimated 0.3% of this water-borne inventory was removed into the sediments. Windscale to C.S.A. transit and residence times of 4 and 12 months respectively were derived. Monitoring the deeper levels of L. Etive allowed 137 Cs to be used to trace patterns of w

  16. Chronic toxicity of nickel-spiked freshwater sediments: variation in toxicity among eight invertebrate taxa and eight sediments

    Science.gov (United States)

    Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.; Ivey, Chris D.; Kunz, James L.; Kemble, Nile E.; Schlekat, Christian E.; Garman, Emily R.

    2013-01-01

    This study evaluated the chronic toxicity of Ni-spiked freshwater sediments to benthic invertebrates. A 2-step spiking procedure (spiking and sediment dilution) and a 2-stage equilibration period (10 wk anaerobic and 1 wk aerobic) were used to spike 8 freshwater sediments with wide ranges of acid-volatile sulfide (AVS; 0.94–38 µmol/g) and total organic carbon (TOC; 0.42–10%). Chronic sediment toxicity tests were conducted with 8 invertebrates (Hyalella azteca, Gammarus pseudolimnaeus, Chironomus riparius, Chironomus dilutus, Hexagenia sp., Lumbriculus variegatus, Tubifex tubifex, and Lampsilis siliquoidea) in 2 spiked sediments. Nickel toxicity thresholds estimated from species-sensitivity distributions were 97 µg/g and 752 µg/g (total recoverable Ni; dry wt basis) for sediments with low and high concentrations of AVS and TOC, respectively. Sensitive species were tested with 6 additional sediments. The 20% effect concentrations (EC20s) for Hyalella and Gammarus, but not Hexagenia, were consistent with US Environmental Protection Agency benchmarks based on Ni in porewater and in simultaneously extracted metals (SEM) normalized to AVS and TOC. For Hexagenia, sediment EC20s increased at less than an equimolar basis with increased AVS, and toxicity occurred in several sediments with Ni concentrations in SEM less than AVS. The authors hypothesize that circulation of oxygenated water by Hexagenia led to oxidation of AVS in burrows, creating microenvironments with high Ni exposure. Despite these unexpected results, a strong relationship between Hexagenia EC20s and AVS could provide a basis for conservative site-specific sediment quality guidelines for Ni.

  17. The use of bioassays to assess the toxicity of sediment in an acid ...

    African Journals Online (AJOL)

    Exposure of river sediment from 7 sampling sites to these bioassays provided an eco-toxicological estimation of the acute toxicity and chronic toxicity emanating from the contaminated sediments. Physico-chemical analyses revealed higher levels of sediment contamination closer to the mine. The bioassays displayed a ...

  18. Surface complexation modeling for predicting solid phase arsenic concentrations in the sediments of the Mississippi River Valley alluvial aquifer, Arkansas, USA

    Science.gov (United States)

    Sharif, M.S.U.; Davis, R.K.; Steele, K.F.; Kim, B.; Hays, P.D.; Kresse, T.M.; Fazio, J.A.

    2011-01-01

    The potential health impact of As in drinking water supply systems in the Mississippi River Valley alluvial aquifer in the state of Arkansas, USA is significant. In this context it is important to understand the occurrence, distribution and mobilization of As in the Mississippi River Valley alluvial aquifer. Application of surface complexation models (SCMs) to predict the sorption behavior of As and hydrous Fe oxides (HFO) in the laboratory has increased in the last decade. However, the application of SCMs to predict the sorption of As in natural sediments has not often been reported, and such applications are greatly constrained by the lack of site-specific model parameters. Attempts have been made to use SCMs considering a component additivity (CA) approach which accounts for relative abundances of pure phases in natural sediments, followed by the addition of SCM parameters individually for each phase. Although few reliable and internally consistent sorption databases related to HFO exist, the use of SCMs using laboratory-derived sorption databases to predict the mobility of As in natural sediments has increased. This study is an attempt to evaluate the ability of the SCMs using the geochemical code PHREEQC to predict solid phase As in the sediments of the Mississippi River Valley alluvial aquifer in Arkansas. The SCM option of the double-layer model (DLM) was simulated using ferrihydrite and goethite as sorbents quantified from chemical extractions, calculated surface-site densities, published surface properties, and published laboratory-derived sorption constants for the sorbents. The model results are satisfactory for shallow wells (10.6. m below ground surface), where the redox condition is relatively oxic or mildly suboxic. However, for the deep alluvial aquifer (21-36.6. m below ground surface) where the redox condition is suboxic to anoxic, the model results are unsatisfactory. ?? 2011 Elsevier Ltd.

  19. Incorporation of Fine-Grained Sediment Erodibility Measurements into Sediment Transport Modeling, Capitol Lake, Washington

    Science.gov (United States)

    Stevens, Andrew W.; Gelfenbaum, Guy; Elias, Edwin; Jones, Craig

    2008-01-01

    Capitol Lake was created in 1951 with the construction of a concrete dam and control gate that prevented salt-water intrusion into the newly formed lake and regulated flow of the Deschutes River into southern Puget Sound. Physical processes associated with the former tidally dominated estuary were altered, and the dam structure itself likely caused an increase in retention of sediment flowing into the lake from the Deschutes River. Several efforts to manage sediment accumulation in the lake, including dredging and the construction of sediment traps upriver, failed to stop the lake from filling with sediment. The Deschutes Estuary Feasibility Study (DEFS) was carried out to evaluate the possibility of removing the dam and restoring estuarine processes as an alternative ongoing lake management. An important component of DEFS was the creation of a hydrodynamic and sediment transport model of the restored Deschutes Estuary. Results from model simulations indicated that estuarine processes would be restored under each of four restoration alternatives, and that over time, the restored estuary would have morphological features similar to the predam estuary. The model also predicted that after dam-removal, a large portion of the sediment eroded from the lake bottom would be deposited near the Port of Olympia and a marina located in lower Budd Inlet seaward of the present dam. The volume of sediment transported downstream was a critical piece of information that managers needed to estimate the total cost of the proposed restoration project. However, the ability of the model to predict the magnitude of sediment transport in general and, in particular, the volume of sediment deposition in the port and marina was limited by a lack of information on the erodibility of fine-grained sediments in Capitol Lake. Cores at several sites throughout Capitol Lake were collected between October 31 and November 1, 2007. The erodibility of sediments in the cores was later determined in the

  20. Maywood Interim Storage Site environmental report for calendar year 1992, 100 West Hunter Avenue, Maywood, New Jersey. Formerly Utilized Sites Remedial Action Program (FUSRAP)

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    This report describes the environmental surveillance program at the Maywood Interim Storage Site (MISS) and provides the results for 1992. Environmental monitoring of MISS began in 1984, when the site was assigned to DOE by Congress through the Energy and Water Development Appropriations Act and was placed under DOE`s Formerly Utilized Sites Remedial Action Program (FUSRAP). FUSRAP was established to identify and decontaminate or otherwise control sites where residual radioactive materials remain from the early years of the nation`s atomic energy program or from commercial operations causing conditions that Congress has authorized DOE to remedy. MISS is part of a National Priorities List (NPL) site. The environmental surveillance program at MISS includes sampling networks for radon and thoron in air; external gamma radiation exposure; and radium-226, radium-228, thorium-232, and total uranium in surface water, sediment, and groundwater. Additionally, chemical analysis includes metals and organic compounds in surface water and groundwater and metals in sediments. This program assists in fulfilling the DOE objective of measuring and monitoring effluents from DOE activities and calculating hypothetical doses to members of the general public. Monitoring results are compared with applicable Environmental Protection Agency (EPA) and state standards, DOE derived concentration guides (DCGs), dose limits, and other DOE requirements. Environmental standards are established to protect public health and the environment. The radiological data for all media sampled support the conclusion that doses to the public are not distinguishable from natural background radiation.

  1. Rare earth, major and trace element composition of Leg 127 sediments

    Science.gov (United States)

    Murray, R.W.; Buchholtz ten Brink, Marilyn R.; Brumsack, Hans-Juergen; Gerlach, David C.; Russ III, G. Price

    1992-01-01

    The relative effects of paleoceanographic and paleogeographic variations, sediment lithology, and diagenetic processes on the final preserved chemistry of Japan Sea sediments are evaluated by investigating the rare earth element (REE), major element, and trace element concentrations in 59 squeeze-cake whole-round and 27 physical-property sample residues from Sites 794, 795, and 797, cored during ODP Leg 127. The most important variation in sedimentary chemical composition is the increase in SiO2 concentration through the Pliocene diatomaceous sequences, which dilutes most other major and trace element components by various degrees. This biogenic input is largest at Site 794 (Yamato Basin), moderately developed at Site 797 (Yamato Basin), and of only minor importance at Site 795 (Japan Basin), potentially reflecting basinal contrasts in productivity with the Yamato Basin recording greater biogenic input than the Japan Basin and with the easternmost sequence of Site 794 lying beneath the most productive waters. There are few systematic changes in solid-phase chemistry resulting from the opal-A/opal-CT or opal-CT/quartz silica phase transformations. Most major and trace element concentrations are controlled by the aluminosilicate fraction of the sediment, although the effects of diagenetic silica phases and manganese carbonates are of localized importance. REE total abundances (IREE) in the Japan Sea are strongly dependent upon the paleoceanographic position of a given site with respect to terrigenous and biogenic sources. REE concentrations at Site 794 overall correspond well to aluminosilicate chemical indices and are strongly diluted by SiO2 within the upper Miocene-Pliocene diatomaceous sequence. Eu/Eu* values at Site 794 reach a maximum through the diatomaceous interval as well, most likely suggesting an association of Eu/Eu* with the siliceous component, or reflecting slight incorporation of a detrital feldspar phase. XREE at Site 795 also is affiliated strongly

  2. Reactive silica fractions in coastal lagoon sediments from the northern Gulf of Mexico

    Science.gov (United States)

    Krause, Jeffrey W.; Darrow, Elizabeth S.; Pickering, Rebecca A.; Carmichael, Ruth H.; Larson, Ashley M.; Basaldua, Jose L.

    2017-12-01

    Continental-margin sediments account for 50% of the oceanic biogenic silica burial despite covering Gulf of Mexico (nGoM), we measured sediment biogenic silica at sites removed from major freshwater discharge sources using the traditional method and a method that has been modified for deltaic systems to quantify other reactive silica pools, specifically those involved in the process of reverse weathering. The magnitude of authigenically-altered biogenic silica during our study was significant and represented, on average, 33% of the total sediment biogenic silica among core depths and sites. Additionally, there was a significant relationship between the degree to which the biogenic silica pool was authigenically altered and the source of the sediment organic matter, with lower modification in sediments corresponding with higher terrestrial organic matter. We observed no positive correlation between the magnitude of authigenic modification and sediment clay content. Thus, our findings suggest that these processes may occur within a variety of sediment compositions and add to a growing body of evidence suggesting that reverse weathering of silica in coastal systems is a significant pathway in the global silica budget.

  3. Soils Activity Mobility Study: Methodology and Application

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-09-29

    and labor- and data-intensive methods. For the watersheds analyzed in this report using the Level 1 PSIAC method, the risk of erosion is low. The field reconnaissance surveys of these watersheds confirm the conclusion that the sediment yield of undisturbed areas at the NNSS would be low. The climate, geology, soils, ground cover, land use, and runoff potential are similar among these watersheds. There are no well-defined ephemeral channels except at the Smoky and Plutonium Valley sites. Topography seems to have the strongest influence on sediment yields, as sediment yields are higher on the steeper hill slopes. Lack of measured sediment yield data at the NNSS does not allow for a direct evaluation of the yield estimates by the PSIAC method. Level 2 MUSLE estimates in all the analyzed watersheds except Shasta are a small percentage of the estimates from PSIAC because MUSLE is not inclusive of channel erosion. This indicates that channel erosion dominates the total sediment yield in these watersheds. Annual sediment yields for these watersheds are estimated using the CHAN-SEDI and CHAN-SEDII channel sediment transport models. Both transport models give similar results and exceed the estimates obtained from PSIAC and MUSLE. It is recommended that the total watershed sediment yield of watersheds at the NNSS with flow channels be obtained by adding the washload estimate (rill and inter-rill erosion) from MUSLE to that obtained from channel transport models (bed load and suspended sediment). PSIAC will give comparable results if factor scores for channel erosion are revised towards the high erosion level. Application of the Level 3 process-based models to estimate sediment yields at the NNSS cannot be recommended at this time. Increased model complexity alone will not improve the certainty of the sediment yield estimates. Models must be calibrated against measured data before model results are accepted as certain. Because no measurements of sediment yields at the NNSS are

  4. Assessment of sediment contamination in Casco Bay, Maine, USA

    Energy Technology Data Exchange (ETDEWEB)

    Wade, Terry L. [Geochemical and Environmental Research Group, Texas A and M University, 833 Graham Road, College Station, TX 77845 (United States); Sweet, Stephen T. [Geochemical and Environmental Research Group, Texas A and M University, 833 Graham Road, College Station, TX 77845 (United States)], E-mail: sweet@gerg.tamu.edu; Klein, Andrew G. [Geography Department, Texas A and M University, 814B Eller O and M Building, College Station, TX 77843 (United States)

    2008-04-15

    The current status of contaminant concentrations in Casco Bay, decadal trends of these contaminants and changes in their geographical distribution are assessed using sediment samples collected approximately 10 years apart. In general, regulated contaminants appeared to be decreasing in concentration. Total PAH and dioxins/furans concentrations did not significantly change over this period. Total organochlorine pesticides, 4,4-DDE, 4,4-DDD, total DDT, PCB, tributyltin and total butyltin decreased in concentration. Trace element concentrations in sediments decreased at the majority of the sampling sites for chromium, nickel, and selenium while arsenic, cadmium, copper, lead, mercury, silver, and zinc remained relatively constant. None of the contaminants measured has increased by more than a factor of 2. Selected sites located in the Inner Bay, where concentrations are higher and new inputs were more likely, showed increased concentrations of contaminants. Most contaminants were not found at concentrations expected to adversely affect sediment biota based on ERL/ERM guidelines. - Sediment studies indicate decadal decreases for many chemical contaminants in Casco Bay.

  5. Assessment of sediment contamination in Casco Bay, Maine, USA

    International Nuclear Information System (INIS)

    Wade, Terry L.; Sweet, Stephen T.; Klein, Andrew G.

    2008-01-01

    The current status of contaminant concentrations in Casco Bay, decadal trends of these contaminants and changes in their geographical distribution are assessed using sediment samples collected approximately 10 years apart. In general, regulated contaminants appeared to be decreasing in concentration. Total PAH and dioxins/furans concentrations did not significantly change over this period. Total organochlorine pesticides, 4,4-DDE, 4,4-DDD, total DDT, PCB, tributyltin and total butyltin decreased in concentration. Trace element concentrations in sediments decreased at the majority of the sampling sites for chromium, nickel, and selenium while arsenic, cadmium, copper, lead, mercury, silver, and zinc remained relatively constant. None of the contaminants measured has increased by more than a factor of 2. Selected sites located in the Inner Bay, where concentrations are higher and new inputs were more likely, showed increased concentrations of contaminants. Most contaminants were not found at concentrations expected to adversely affect sediment biota based on ERL/ERM guidelines. - Sediment studies indicate decadal decreases for many chemical contaminants in Casco Bay

  6. Influence Of Groundwater Discharge On Arsenic Contamination In Sediments

    Science.gov (United States)

    A field investigation was conducted to evaluate the impact of a discharging arsenic plume on sediment contaminant characteristics at a site adjacent to a landfill in northeastern Massachusetts. Site characterization included assessment of the hydrologic and chemical samples coll...

  7. The effect of sediment thermal conductivity on vertical groundwater flux estimates

    Science.gov (United States)

    Sebok, Eva; Müller, Sascha; Engesgaard, Peter; Duque, Carlos

    2015-04-01

    The interaction between groundwater and surface water is of great importance both from ecological and water management perspective. The exchange fluxes are often estimated based on vertical temperature profiles taken from shallow sediments assuming a homogeneous standard value of sediment thermal conductivity. Here we report on a field investigation in a stream and in a fjord, where vertical profiles of sediment thermal conductivity and temperatures were measured in order to, (i) define the vertical variability in sediment thermal conductivity, (ii) quantify the effect of heterogeneity in sediment thermal conductivity on the estimated vertical groundwater fluxes. The study was carried out at field sites located in Ringkøbing fjord and Holtum stream in Western Denmark. Both locations have soft, sandy sediments with an upper organic layer at the fjord site. First 9 and 12 vertical sediment temperature profiles up to 0.5 m depth below the sediment bed were collected in the fjord and in the stream, respectively. Later sediment cores of 0.05 m diameter were removed at the location of the temperature profiles. Sediment thermal conductivity was measured in the sediment cores at 0.1 m intervals with a Decagon KD2 Pro device. A 1D flow and heat transport model (HydroGeoSphere) was set up and vertical groundwater fluxes were estimated based on the measured vertical sediment temperature profiles by coupling the model with PEST. To determine the effect of heterogeneity in sediment thermal conductivity on estimated vertical groundwater fluxes, the model was run by assigning (i) a homogeneous thermal conductivity for all sediment layers, calculated as the average sediment thermal conductivity of the profile, (ii) measured sediment thermal conductivities to the different model layers. The field survey showed that sediment thermal conductivity over a 0.5 m profile below the sediment bed is not uniform, having the largest variability in the fjord where organic sediments were also

  8. Chemical characteristics of urban stormwater sediments and implications for environmental management, Maricopa County, Arizona

    Science.gov (United States)

    Parker, J.T.C.; Fossum, K.D.; Ingersoll, T.L.

    2000-01-01

    Investigations of the chemical characteristics of urban stormwater sediments in the rapidly growing Phoenix metropolitan area of Maricopa County, Arizona, showed that the inorganic component of these sediments generally reflects geologic background values. Some concentrations of metals were above background values, especially cadmium, copper, lead, and zinc, indicating an anthropogenic contribution of these elements to the sediment chemistry. Concentrations, however, were not at levels that would require soil remediation according to guidelines of the U.S. Environmental Protection Agency. Arsenic concentrations generally were above recommended values for remediation at a few sites, but these concentrations seem to reflect geologic rather than anthropogenic factors. Several organochlorine compounds no longer in use were ubiquitous in the Phoenix area, although concentrations generally were low. Chlordane, DDT and its decay products DDE and DDD, dieldrin, toxaphene, and PCBs were found at almost all sites sampled, although some of the pesticides in which these compounds are found have been banned for almost 30 years. A few sites showed exceptionally high concentrations of organochlorine compounds. On the basis of published guidelines, urban stormwater sediments do not appear to constitute a major regional environmental problem with respect to the chemical characteristics investigated here. At individual sites, high concentrations of organic compounds - chlordane, dieldrin, PCBs, and toxaphene - may require some attention. The possible environmental hazard presented by low-level organochlorine contamination is not addressed in this paper; however, high levels of toxicity in urban sediments are difficult to explain. Sediment toxicity varied significantly with time, which indicates that these tests should be evaluated carefully before they are used for management decisions.Investigations of the chemical characteristics of urban stormwater sediments in the rapidly

  9. Sedimentation patterns in floodplains of the Mekong Delta - Vietnam

    Science.gov (United States)

    Van Manh, Nguyen; Merz, Bruno; Viet Dung, Nguyen; Apel, Heiko

    2013-04-01

    Quantification of floodplain sedimentation during the flood season in the Mekong Delta (MD) plays a very important role in the assessment of flood deposits for a sustainable agro-economic development. Recent studies on floodplain sedimentation in the region are restricted to small pilot sites because of the large extend of the Delta, and the complex channel. This research aims at a quantification of the sediment deposition in floodplains of the whole Mekong Delta, and to access the impacts of the upstream basin development on the sedimentation in the Delta quantitatively. To achieve this, a suspended sediment transport model is developed based on the quasi-2D hydrodynamic model of the whole Mekong Delta developed by Dung et al. (2011). The model is calibrated and validated using observed data derived from several sediment measurement campaigns in channel networks and floodplains. Measured sediment data and hydrodynamic model quantify the spatio-temporal variability of sediment depositions in different spatial units: individual dyke compartments, and the sub-regions Plain of Reeds, Long Xuyen Quadrangle and the area between Tien River and Hau River. It is shown that the distribution of sediment deposition over the delta is highly depended on the flood magnitude, that in turn drives the operation policy of flood control systems in floodplains of the Mekong Delta. Thus, the sedimentation distribution is influenced by the protection level of the dyke systems in place and the distance to the Tien River and Hau River, the main branches of the Mekong in the Delta. This corroborates the main findings derived from data analysis obtained from a small scale test site by Hung et al, (2011, 2012a). Moreover, the results obtained here underlines the importance of the main channels for the sediment transport into the floodplains, and the deposition rate in floodplains is strongly driven by the intake locations and the distance from these to the main channels as well.

  10. Radioactive and radiogenic isotopes in sediments from Cooper Creek, Western Arnhem Land

    Energy Technology Data Exchange (ETDEWEB)

    Frostick, A. [Charles Darwin University, Darwin, NT 0909 (Australia); ERISS, GPO Box 461, Darwin, NT 0801 (Australia)], E-mail: alison.frostick@cdu.edu.au; Bollhoefer, A. [ERISS, GPO Box 461, Darwin, NT 0801 (Australia); Parry, D.; Munksgaard, N. [Charles Darwin University, Darwin, NT 0909 (Australia); Evans, K. [ERISS, GPO Box 461, Darwin, NT 0801 (Australia)

    2008-03-15

    Protection of the environment post-mining is a key objective of rehabilitation, especially where runoff and erosion from rehabilitated mine sites could potentially lead to contamination of the surrounding land and watercourses. As part of an overall assessment of the success of rehabilitation at the former Nabarlek uranium (U) mine, an appraisal of stable lead (Pb) isotopes, radionuclides and trace metals within sediments and soils was conducted to determine the off site impacts from a spatial and temporal perspective. The study found localised areas on and adjacent to the site where soils had elevated levels of trace metals and radionuclides. Lead isotope ratios are highly radiogenic in some samples, indicating the presence of U-rich material. There is some indication that erosion products with more radiogenic Pb isotope ratios have deposited in sediments downstream of the former ore body. However, there is no indication that the radiogenic erosion products found on the mine site at present have significantly contaminated sediments further downstream of Cooper Creek.

  11. Radioactive and radiogenic isotopes in sediments from Cooper Creek, Western Arnhem Land

    International Nuclear Information System (INIS)

    Frostick, A.; Bollhoefer, A.; Parry, D.; Munksgaard, N.; Evans, K.

    2008-01-01

    Protection of the environment post-mining is a key objective of rehabilitation, especially where runoff and erosion from rehabilitated mine sites could potentially lead to contamination of the surrounding land and watercourses. As part of an overall assessment of the success of rehabilitation at the former Nabarlek uranium (U) mine, an appraisal of stable lead (Pb) isotopes, radionuclides and trace metals within sediments and soils was conducted to determine the off site impacts from a spatial and temporal perspective. The study found localised areas on and adjacent to the site where soils had elevated levels of trace metals and radionuclides. Lead isotope ratios are highly radiogenic in some samples, indicating the presence of U-rich material. There is some indication that erosion products with more radiogenic Pb isotope ratios have deposited in sediments downstream of the former ore body. However, there is no indication that the radiogenic erosion products found on the mine site at present have significantly contaminated sediments further downstream of Cooper Creek

  12. Evaluation of an in-situ x-ray fluorescence analyzer for inorganic pollutants in sediments and water columns

    International Nuclear Information System (INIS)

    Wogman, N.A.

    1979-09-01

    The applicability of an energy dispersive x-ray fluorescence spectrometer for measurement of trace elements in sediments and in water columns from Coast Guard vessels has been investigated. This investigation was conducted in both freshwater and saltwater areas and included Puget Sound, Lake Washington, Lake Union, and the ship canal in the State of Washington. The spectrometer system consisted of a solid cryogen-cooled Si(Li) detector and a 109 Cd excitation source. Sediments and water columns were viewed through a 0.2 mm Be window. This study showed the feasibility of measuring trace elements at concentrations ranging from 20 to about 100 ppM. Measurements of this sensitivity with a 100 mCi 109 Cd source are possible for time intervals as short as 5 minutes. This in-situ measurement capability permits the on-site mapping of pollution and avoids the problem of sediment disturbance which is inherent in the collection of grab samples of the sediment surface. Recommendations for an improved analyzer system included a detector assembly which could be towed, or allow continuous sediment surface analysis thereby recording the average composition of a large area

  13. Ascribing soil erosion of hillslope components to river sediment yield.

    Science.gov (United States)

    Nosrati, Kazem

    2017-06-01

    In recent decades, soil erosion has increased in catchments of Iran. It is, therefore, necessary to understand soil erosion processes and sources in order to mitigate this problem. Geomorphic landforms play an important role in influencing water erosion. Therefore, ascribing hillslope components soil erosion to river sediment yield could be useful for soil and sediment management in order to decrease the off-site effects related to downstream sedimentation areas. The main objectives of this study were to apply radionuclide tracers and soil organic carbon to determine relative contributions of hillslope component sediment sources in two land use types (forest and crop field) by using a Bayesian-mixing model, as well as to estimate the uncertainty in sediment fingerprinting in a mountainous catchment of western Iran. In this analysis, 137 Cs, 40 K, 238 U, 226 Ra, 232 Th and soil organic carbon tracers were measured in 32 different sampling sites from four hillslope component sediment sources (summit, shoulder, backslope, and toeslope) in forested and crop fields along with six bed sediment samples at the downstream reach of the catchment. To quantify the sediment source proportions, the Bayesian mixing model was based on (1) primary sediment sources and (2) combined primary and secondary sediment sources. The results of both approaches indicated that erosion from crop field shoulder dominated the sources of river sediments. The estimated contribution of crop field shoulder for all river samples was 63.7% (32.4-79.8%) for primary sediment sources approach, and 67% (15.3%-81.7%) for the combined primary and secondary sources approach. The Bayesian mixing model, based on an optimum set of tracers, estimated that the highest contribution of soil erosion in crop field land use and shoulder-component landforms constituted the most important land-use factor. This technique could, therefore, be a useful tool for soil and sediment control management strategies. Copyright

  14. Applications of Ecological Engineering Remedies for Uranium Processing Sites, USA

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, William [Navarro Research and Engineering

    2016-05-23

    The U.S. Department of Energy (USDOE) is responsible for remediation of environmental contamination and long-term stewardship of sites associated with the legacy of nuclear weapons production during the Cold War in the United States. Protection of human health and the environment will be required for hundreds or even thousands of years at many legacy sites. USDOE continually evaluates and applies advances in science and technology to improve the effectiveness and sustainability of surface and groundwater remedies (USDOE 2011). This paper is a synopsis of ecological engineering applications that USDOE is evaluating to assess the effectiveness of remedies at former uranium processing sites in the southwestern United States. Ecological engineering remedies are predicated on the concept that natural ecological processes at legacy sites, once understood, can be beneficially enhanced or manipulated. Advances in tools for characterizing key processes and for monitoring remedy performance are demonstrating potential. We present test cases for four ecological engineering remedies that may be candidates for international applications.

  15. A methodology for the assessment of rehabilitation success of post mining landscapes-sediment and radionuclide transport at the former Nabarlek uranium mine, Northern Territory, Australia

    International Nuclear Information System (INIS)

    Hancock, G.R.; Grabham, M.K.; Martin, P; Evans, K.G.; Bollhoefer, A.

    2006-01-01

    Protection of the environment post-mining is an important issue, especially where runoff and erosion can lead to undesirable material leaving post-mining landscapes and contaminating surrounding land and watercourses. Methods for assessment of the environmental impact and long-term behaviour of post-mining landforms based on scientific methodology are needed especially where field data are absent or poor. An appraisal of the former Nabarlek uranium mine was conducted to assess the site from a soil erosion perspective as part of an independent evaluation of overall rehabilitation success. Determination of the gross erosion occurring, sediment discharge to Cooper Creek and the resultant sediment associated radionuclide load in Cooper Creek were the primary objectives of the study. These objectives were achieved through the application of several models using parameter values collected from the site. The study found that the area containing the mill tailings repository is extremely stable and meets the guidelines established for long-term storage of uranium mill tailings. Most other areas on the site are stable; however there are some areas with a high sediment loss. Sediment concentration in Cooper Creek, which drains the site, was found to be within the Australian water quality guidelines for fresh water, however sediment concentrations in tributaries were found to exceed recommended levels. Radionuclide determinations on soil samples showed that the highest specific activities (Bq kg -1 ) were present on a small (0.44 ha) area with a relatively high erosion rate. This small area contributed the majority of the estimated flux to Cooper Creek of uranium-series radionuclides sorbed or structurally incorporated to eroded soil particles sourced from the mine site. This study provides a methodology for assessment of the erosional stability of such a landscape and consequent impact on water quality, using extensive field data and readily available and well known models

  16. Analysis of Fluvial Sediment Discharges into Kubanni Reservoir ...

    African Journals Online (AJOL)

    User

    The predominant sandy-clay sediment in the reservoir has an estimated total sediment load ... NIGERIAN JOURNAL OF TECHNOLOGY, VOL. 29 NO 2, JUNE ... the upper limit of application is 1-5gl !1 ... Laursen, Modified Einstein Procedure,.

  17. Power plant siting; an application of the nominal group process technique

    International Nuclear Information System (INIS)

    Voelker, A.H.

    1976-01-01

    The application of interactive group processes to the problem of facility siting is examined by this report. Much of the discussion is abstracted from experience gained in applying the Nominal Group Process Technique, an interactive group technique, to the identification and rating of factors important in siting nuclear power plants. Through this experience, interactive group process techniques are shown to facilitate the incorporation of the many diverse factors which play a role in siting. In direct contrast to mathematical optimization, commonly represented as the ultimate siting technique, the Nominal Group Process Technique described allows the incorporation of social, economic, and environmental factors and the quantification of the relative importance of these factors. The report concludes that the application of interactive group process techniques to planning and resource management will affect the consideration of social, economic, and environmental concerns and ultimately lead to more rational and credible siting decisions

  18. Measuring the role of seagrasses in regulating sediment surface elevation

    KAUST Repository

    Potouroglou, Maria

    2017-09-13

    Seagrass meadows provide numerous ecosystem services and their rapid global loss may reduce human welfare as well as ecological integrity. In common with the other \\'blue carbon\\' habitats (mangroves and tidal marshes) seagrasses are thought to provide coastal defence and encourage sediment stabilisation and surface elevation. A sophisticated understanding of sediment elevation dynamics in mangroves and tidal marshes has been gained by monitoring a wide range of different sites, located in varying hydrogeomorphological conditions over long periods. In contrast, similar evidence for seagrasses is sparse; the present study is a contribution towards filling this gap. Surface elevation change pins were deployed in four locations, Scotland, Kenya, Tanzania and Saudi Arabia, in both seagrass and unvegetated control plots in the low intertidal and shallow subtidal zone. The presence of seagrass had a highly significant, positive impact on surface elevation at all sites. Combined data from the current work and the literature show an average difference of 31 mm per year in elevation rates between vegetated and unvegetated areas, which emphasizes the important contribution of seagrass in facilitating sediment surface elevation and reducing erosion. This paper presents the first multi-site study for sediment surface elevation in seagrasses in different settings and species.

  19. Measuring the role of seagrasses in regulating sediment surface elevation

    Science.gov (United States)

    Potouroglou, Maria; Bull, James C.; Krauss, Ken W.; Kennedy, Hilary A.; Fusi, Marco; Daffonchio, Daniele; Mangora, Mwita M.; Githaiga, Michael N.; Diele, Karen; Huxham, Mark

    2017-01-01

    Seagrass meadows provide numerous ecosystem services and their rapid global loss may reduce human welfare as well as ecological integrity. In common with the other ‘blue carbon’ habitats (mangroves and tidal marshes) seagrasses are thought to provide coastal defence and encourage sediment stabilisation and surface elevation. A sophisticated understanding of sediment elevation dynamics in mangroves and tidal marshes has been gained by monitoring a wide range of different sites, located in varying hydrogeomorphological conditions over long periods. In contrast, similar evidence for seagrasses is sparse; the present study is a contribution towards filling this gap. Surface elevation change pins were deployed in four locations, Scotland, Kenya, Tanzania and Saudi Arabia, in both seagrass and unvegetated control plots in the low intertidal and shallow subtidal zone. The presence of seagrass had a highly significant, positive impact on surface elevation at all sites. Combined data from the current work and the literature show an average difference of 31 mm per year in elevation rates between vegetated and unvegetated areas, which emphasizes the important contribution of seagrass in facilitating sediment surface elevation and reducing erosion. This paper presents the first multi-site study for sediment surface elevation in seagrasses in different settings and species.

  20. Sedimentation rate and {sup 210}Pb sediment dating at Apipucos reservoir, Recife, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, Marcela D.C. de; Silva, Danubia B. da; Cunha, Manuela S. da; Rodrigues, Kelia R.G.; Pedroza, Eryka H.; Melo, Roberto T. de; Oliveira, Aristides; Hazin, Clovis A.; Souza, Vivianne L.B. de, E-mail: rtmelo@cnen.gov.b, E-mail: chazin@cnen.gov.b, E-mail: vlsouza@cnen.gov.b [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2011-07-01

    The Apipucos Reservoir is located in Recife, State of Pernambuco, and, several districts of the metropolitan area use this reservoir to dispose waste and sewage. Dating sediments uses {sup 210}Pb from the atmosphere which is formed as a result of {sup 222}Rn emanation from the soil. Atmospheric lead, carried by rain, is called non-supported {sup 21}'0Pb, to differentiate it from the one contained in the sediment, in balance with the {sup 226}Ra. The model chosen for dating sediments depends on certain conditions: in an environment where the amount of sediment influx can vary, the constant rate of supply model is adopted. On the other hand, in environments where the sedimentation rate is constant and the sediment can be considered to have a constant initial concentration of unsupported {sup 210}Pb and the (CIC) model is applied. A 70-cm long, 5-cm internal-diameter wide core was collected for sediment dating. Each core was sliced, into 5 or 10 cm intervals. Samples were dried at 105 deg C, and about 5 g dry material from each sample was dissolved with acids. The {sup 210}Pb and {sup 226}Ra contents were separated and determined by beta and alpha counting by using a gas-flow proportional counter. Sediment ages were calculated by the two models, and for the second and fourth sampling points, both models could be used. The results showed an increase in sedimentation rate over the last 50 - 60 years. We can conclude that the top sediment layer is dated from 30 years ago. We can also conclude that the CRS is the best applicable model to use in this area. (author)

  1. Pollutants' Release, Redistribution and Remediation of Black Smelly River Sediment Based on Re-Suspension and Deep Aeration of Sediment.

    Science.gov (United States)

    Zhu, Lin; Li, Xun; Zhang, Chen; Duan, Zengqiang

    2017-04-01

    Heavily polluted sediment is becoming an important part of water pollution, and this situation is particularly acute in developing countries. Sediment has gradually changed from being the pollution adsorbent to the release source and has influenced the water environment and public health. In this study, we evaluated the pollutant distribution in sediment in a heavily polluted river and agitated the sediment in a heavily polluted river to re-suspend it and re-release pollutants. We found that the levels of chemical oxygen demand (COD), NH₄⁺-N, total nitrogen (TN), and total phosphorus (TP) in overlying water were significantly increased 60 min after agitation. The distribution of the pollutants in the sediment present high concentrations of pollutants congregated on top of the sediment after re-settling, and their distribution decreased with depth. Before agitation, the pollutants were randomly distributed throughout the sediment. Secondly, deep sediment aeration equipment (a micro-porous air diffuser) was installed during the process of sedimentation to study the remediation of the sediment by continuous aeration. The results revealed that deep sediment aeration after re-suspension significantly promoted the degradation of the pollutants both in overlying water and sediment, which also reduced the thickness of the sediment from 0.9 m to 0.6 m. Therefore, sediment aeration after suspension was efficient, and is a promising method for sediment remediation applications.

  2. Knoxville 10 x 20 NTMS area, North Carolina, South Carolina, and Tennessee: data release. Hydrogeochemical and stream sediment reconnaissance

    International Nuclear Information System (INIS)

    Baucom, E.I.; Ferguson, R.B.

    1979-05-01

    Stream sediment and stream water samples were collected from small streams at 1430 sites or at a nominal density of one site per 14 square kilometers (five square miles) in rural areas. Ground water samples were collected at 791 sites or at a nominal density of one site per 25 square kilometers (ten square miles). Neutron activation analysis (NAA) results are given for uranium and 16 other elements in sediments, and for uranium and 9 other elements in ground water. Key data from ground water sites include (1) water chemistry measurements (pH, conductivity, and alkalinity), (2) well depth, (3) elemental analyses (U, Br, Cl, F, Mg, Mn, Na, and V). Supplementary data include site descriptors (well age, frequency of use of well, etc.) and tabulated analytical data for Al and Dy. Key data from stream sediment sites include (1) water quality measurements (pH, conductivity, and alkalinity), and (2) important elemental analyses (U, Th, Hf, Al, Ce, Fe, Mn, Na, Sc, Ti, and V). Supplementary data from stream sediment sites include sample site descriptors (stream characteristics, vegetation, etc.) and additional elemental analyses

  3. Contaminant characterization of sediment and pore-water in the Clinch River and Poplar Creek

    International Nuclear Information System (INIS)

    Levine, D.A.; Harris, R.A.; Campbell, K.R.; Hargrove, W.W.; Rash, C.D.

    1995-01-01

    Sediment and pore-water samples were collected from 80 locations in the Clinch River and Poplar Creek system to characterize concentrations and spatial distribution of contaminants for use in ecological risk assessment. Sediment cores were collected at each site and the top 15 cm was analyzed to represent the biologically active zone. Sediment for pore-water extraction was collected in large volumes using a Ponar grab sampler. Pore-water was extracted from this sediment using centrifugation, All samples were analyzed for metals (including methyl mercury), organics, and radiological constituents. Additionally, sediment was analyzed for physical properties: particle size distribution, density, and porosity. Sediment and pore-water were also analyzed for total organic carbon and nitrogen and ammonia levels. Sediment and pore-water were also analyzed for total organic carbon and nitrogen and ammonia levels. Sediment and pre-water results indicate that there are several areas where concentrations of a variety of contaminants are high enough to causes ecological effects. These locations in the river are immediately downstream from know sources of Contamination from on-site DOE facilities. East Fork Poplar Creek is a source of several metals, including mercury, cadmium, chromium, and copper. Mitchell Branch is a source of number of metals, uranium isotopes, technetium-99, and several PAHs. There are two clear sources of arsenic and selenium to the system, one in Poplar Creek and one in Melton Hill Reservoir, both related to past disposal of coal-ash. High concentrations in sediments did not always coincide with high concentrations in pore-water for the same sites and contaminants. This appears to be related to particle size of the sediment and total organic carbon

  4. Biosolids, Soil, Crop, Ground-Water, and Streambed-Sediment Data for a Biosolids-Application Area Near Deer Trail, Colorado, 2002-2003

    National Research Council Canada - National Science Library

    Yager, Tracy J; Smith, David B; Crock, James G

    2004-01-01

    .... Monitoring components were biosolids, soils, crops, ground water, and streambed sediments. The monitoring program addresses concerns from the public about chemical effects from applications of biosolids to farmland in the Deer Trail, Colorado, area...

  5. Effects of pollution on the geochemical properties of marine sediments across the fringing reef of Aqaba, Red Sea.

    Science.gov (United States)

    Al-Rousan, Saber; Al-Taani, Ahmed A; Rashdan, Maen

    2016-09-15

    The Gulf of Aqaba is of significant strategic and economic value to all gulf-bordering states, particularly to Jordan, where it provides Jordan with its only marine outlet. The Gulf is subject to a variety of impacts posing imminent ecological risk to its unique marine ecosystem. We attempted to investigate the status of metal pollution in the coastal sediments of the Jordanian Gulf of Aqaba. The distribution of Cd, Cr, Zn, Cu, Pb, Al, Fe, and Mn concentrations were determined in trapped and bottom-surface sediments at three selected sites at different depths. In addition, monthly sedimentation rates at varying water depths were also estimated at each sampling site using sediment traps. The high concentrations of Cd, Cr, Zn were recorded at the Phosphate Loading Birth (PLB) site followed by the Industrial Complex (IC) site indicating their dominant anthropogenic source (i.e., the contribution of industrial activities). However, Fe, Al, and Mn contents were related to inputs from the terrigenous (crustal) origin. Except for Al, Fe and Mn at the PLB site, the concentrations of metals exhibited a decreasing trend with increasing water depth (distance from the shoreline). The PLB site also showed the highest sedimentation rate which decreased with increasing water depth. The Enrichment factors (EFs) showed that Cd was the most enriched element in the sediment (indicating that Cd pollution is widespread), whereas the least enriched metal in sediments was Cu. EF values suggested that the coastal area is impacted by a combination of human and natural sources of metals, where the anthropogenic sources are intense in the PLB site (north of Gulf of Aqaba). The MSS area is potentially the least polluted, consistent with being a marine reserve. The IC sediments have been found to be impacted by human activities but less intensely compared to the PLB area. These results suggested that there are two sources of metals in sediments; the primary source is likely closer to PLB

  6. Agricultural land use doubled sediment yield of western China's rivers

    Science.gov (United States)

    Schmidt, A. H.; Bierman, P. R.; Sosa-Gonzalez, V.; Neilson, T. B.; Rood, D. H.; Martin, J.; Hill, M.

    2017-12-01

    Land use changes, such as deforestation and agriculture, increase soil erosion rates on the scale of hillslopes and small drainage basins; however, the effects of these changes on the sediment load in larger rivers is poorly quantified, with a few studies scattered globally, and only 10 data points in the world's most populous nation, China. At 20 different sites in western China, we compare contemporary (1945-1987) fluvial sediment yield data collected daily over 4 to 26 years (median = 19 years) to long-term measures of erosion (sediment generation) based on new isotopic measurements of in situ 10Be in river sediments. We find that median sediment transport at these sites exceeds background sediment generation rates by a factor of two (from 0.13 to 5.79 times, median 1.85 times) and that contemporary sediment yield is statistically significantly different from long-term sediment yield (p measured unsupported 210Pb and 137Cs in 130 detrital samples from throughout the region. We find that only 4 samples (those from high elevation, low relief watersheds) have detectable 137Cs and 31 samples have detectable unsupported 210Pb. The lack of 137Cs in most samples suggests high rates of erosion in the 1950s-1960s when 137Cs would have been delivered to the landscape. Detectable 210Pb in 25% of the watersheds suggests that in some areas erosion rates have slowed since that time allowing 210Pb to accumulate to measurable levels. Together, these data sets demonstrate that upstream agricultural land use has significantly increased sediment supply to rivers in western China, likely increasing turbidity and decreasing ecosystem services such as fisheries.

  7. Niagara Falls Storage Site annual environmental report for calendar year 1991, Lewiston, New York. [Niagara Falls Storage Site

    Energy Technology Data Exchange (ETDEWEB)

    1992-09-01

    This document describes the environmental monitoring program at the Niagara Falls Storage Site (NFSS) and surrounding area, implementation of the program, and monitoring results for 1991. Environmental monitoring at NFSS began in 1981. The site is owned by the US Department of Energy (DOE) and is assigned to the DOE Formerly Utilized Sites Remedial Action Program (FUSRAP). FUSRAP is a program to decontaminate or otherwise control sites where residual radioactive materials remain from the early years of the nation's atomic energy program or from commercial operations causing conditions that Congress has authorized DOE to remedy. The environmental monitoring program at NFSS includes sampling networks for radon concentrations in air; external gamma radiation exposure; and total uranium and radium-226 concentrations in surface water, sediments, and groundwater. Additionally, several nonradiological parameters including seven metals are routinely measured in groundwater. Monitoring results are compared with applicable Environmental Protection Agency (EPA) standards, DOE derived concentration guides (DCGs), dose limits, and other requirements in DOE orders. Environmental standards are established to protect public health and the environment.

  8. Assessing condition of macroinvertebrate communities and sediment toxicity in the St. Lawrence River at Massena Area-of-Concern

    Science.gov (United States)

    Duffy, Brian T.; Baldigo, Barry P.; Smith, Alexander J.; George, Scott D.; David, Anthony M.

    2016-01-01

    In 1972, the USA and Canada agreed to restore the chemical, physical, and biological integrity of the Great Lakes ecosystem under the first Great Lakes Water Quality Agreement. In subsequent amendments, part of the St. Lawrence River at Massena, New York and segments of three tributaries, were designated as an Area of Concern (AOC) due to the effects of polychlorinated biphenyls (PCBs), lead and copper contamination, and habitat degradation and resulting impairment to several beneficial uses. Because sediments have been largely remediated, the present study was initiated to evaluate the current status of the benthic macroinvertebrate (benthos) beneficial use impairment (BUI). Benthic macroinvertebrate communities and sediment toxicity tests using Chironomus dilutus were used to test the hypotheses that community condition and sediment toxicity at AOC sites were not significantly different from those of adjacent reference sites. Grain size was found to be the main driver of community composition and macroinvertebrate assemblages, and bioassessment metrics did not differ significantly between AOC and reference sites of the same sediment class. Median growth of C. dilutus and its survival in three of the four river systems did not differ significantly in sediments from AOC and reference sites. Comparable macroinvertebrate assemblages and general lack of toxicity across most AOC and reference sites suggest that the quality of sediments should not significantly impair benthic macroinvertebrate communities in most sites in the St. Lawrence River AOC.

  9. Standard operating procedures for collection of soil and sediment samples for the Sediment-bound Contaminant Resiliency and Response (SCoRR) strategy pilot study

    Science.gov (United States)

    Fisher, Shawn C.; Reilly, Timothy J.; Jones, Daniel K.; Benzel, William M.; Griffin, Dale W.; Loftin, Keith A.; Iwanowicz, Luke R.; Cohl, Jonathan A.

    2015-12-17

    An understanding of the effects on human and ecological health brought by major coastal storms or flooding events is typically limited because of a lack of regionally consistent baseline and trends data in locations proximal to potential contaminant sources and mitigation activities, sensitive ecosystems, and recreational facilities where exposures are probable. In an attempt to close this gap, the U.S. Geological Survey (USGS) has implemented the Sediment-bound Contaminant Resiliency and Response (SCoRR) strategy pilot study to collect regional sediment-quality data prior to and in response to future coastal storms. The standard operating procedure (SOP) detailed in this document serves as the sample-collection protocol for the SCoRR strategy by providing step-by-step instructions for site preparation, sample collection and processing, and shipping of soil and surficial sediment (for example, bed sediment, marsh sediment, or beach material). The objectives of the SCoRR strategy pilot study are (1) to create a baseline of soil-, sand-, marsh sediment-, and bed-sediment-quality data from sites located in the coastal counties from Maine to Virginia based on their potential risk of being contaminated in the event of a major coastal storm or flooding (defined as Resiliency mode); and (2) respond to major coastal storms and flooding by reoccupying select baseline sites and sampling within days of the event (defined as Response mode). For both modes, samples are collected in a consistent manner to minimize bias and maximize quality control by ensuring that all sampling personnel across the region collect, document, and process soil and sediment samples following the procedures outlined in this SOP. Samples are analyzed using four USGS-developed screening methods—inorganic geochemistry, organic geochemistry, pathogens, and biological assays—which are also outlined in this SOP. Because the SCoRR strategy employs a multi-metric approach for sample analyses, this

  10. Recent 137Cs deposition in sediments of Admiralty Bay, Antarctica

    International Nuclear Information System (INIS)

    Sanders, Christian J.; Santos, Isaac R.; Patchineelam, Sambasiva R.; Schaefer, Carlos; Silva-Filho, Emmanoel V.

    2010-01-01

    Cesium-137, radium-226 and lead-210 profiles of a 25 cm sediment core give an indication of recent changes in land-ocean interactions at a polar coastal environment (Admiralty Bay, King George Island, Antarctica). The linear sedimentation accumulation rate at the study site calculated from the unsupported 210 Pb profile was 6.7 mm/year from 1965 to 2005. A 3.5-fold increase in 137 Cs concentrations was observed in the top layer of this sediment core. This sharp increase seems to indicate a recent redistribution of fallout radionuclides previously deposited on soil, vegetation and snow. These results imply enhanced land-ocean interactions at this site likely as a result of climate change. Because our results are based on a single core, additional investigations are needed to confirm our observations.

  11. Introduction to the treatment of polluted sediments

    NARCIS (Netherlands)

    Rulkens, W.H.

    2005-01-01

    This paper overviews the large variety of remediation options for polluted sediments that are currently available. These include physico-chemical and biological techniques that can be applied in situ or ex site.

  12. Radionuclide contaminant analysis of small mammels, plants and sediments within Mortandad Canyon, 1994

    International Nuclear Information System (INIS)

    Bennett, K.; Biggs, J.; Fresquez, P.

    1996-01-01

    Small mammals, plants and sediments were sampled at one upstream location (Site 1) and two downstream locations (Site 2 and Site 3) from the National Pollution Discharge Elimination System outfall number-sign 051-051 in Mortandad Canyon, Los Alamos County, New Mexico. The purpose of the sampling was to identify radionuclides potentially present, to quantitatively estimate and compare the amount of radionuclide uptake at specific locations (Site 2 and Site 3) within Mortandad Canyon to an upstream site (Site 1), and to identify the primary mode (inhalation ingestion, or surface contact) of contamination to small mammals. Three composite samples of at least five animals per sample were collected at each site. Pelts and carcasses of each animal were separated and analyzed independently. In addition, three composite samples were also collected for plants and sediments at each site. Samples were analyzed for 241 Am, 90 Sr, 238 Pu, 239 Pu, and total U. With the exception of total U, all mean radionuclide concentrations in small mammal carcasses and sediments were significantly higher at Site 2 than Site 1 or Site 3. No differences were detected in the mean radionuclide concentration of plant samples between sites. However, some radionuclide concentrations found at all three sites were higher than regional background. No differences were found between mean carcass radionuclide concentrations and mean pelt radionuclide concentrations, indicating that the two primary modes of contamination may be equally occurring

  13. Reservoir Sedimentation and Upstream Sediment Sources: Perspectives and Future Research Needs on Streambank and Gully Erosion

    Science.gov (United States)

    Fox, G. A.; Sheshukov, A.; Cruse, R.; Kolar, R. L.; Guertault, L.; Gesch, K. R.; Dutnell, R. C.

    2016-05-01

    The future reliance on water supply and flood control reservoirs across the globe will continue to expand, especially under a variable climate. As the inventory of new potential dam sites is shrinking, construction of additional reservoirs is less likely compared to simultaneous flow and sediment management in existing reservoirs. One aspect of this sediment management is related to the control of upstream sediment sources. However, key research questions remain regarding upstream sediment loading rates. Highlighted in this article are research needs relative to measuring and predicting sediment transport rates and loading due to streambank and gully erosion within a watershed. For example, additional instream sediment transport and reservoir sedimentation rate measurements are needed across a range of watershed conditions, reservoir sizes, and geographical locations. More research is needed to understand the intricate linkage between upland practices and instream response. A need still exists to clarify the benefit of restoration or stabilization of a small reach within a channel system or maturing gully on total watershed sediment load. We need to better understand the intricate interactions between hydrological and erosion processes to improve prediction, location, and timing of streambank erosion and failure and gully formation. Also, improved process-based measurement and prediction techniques are needed that balance data requirements regarding cohesive soil erodibility and stability as compared to simpler topographic indices for gullies or stream classification systems. Such techniques will allow the research community to address the benefit of various conservation and/or stabilization practices at targeted locations within watersheds.

  14. Dewatering of contaminated river sediments

    Science.gov (United States)

    Church, Ronald H.; Smith, Carl W.; Scheiner, Bernard J.

    1994-01-01

    Dewatering of slurries has been successfully accomplished by the proper use of polymers in flocculating the fine particulate matter suspended in mineral processing streams. The U.S. Bureau of Mines (USBM) entered into a cooperative research effort with the U.S. Army Corps of Engineers (Corps) for the purpose of testing and demonstrating the applicability of mining flocculation technology to dredging activities associated with the removal of sediments from navigable waterways. The Corps has the responsibility for maintaining the navigable waterways in the United States. Current technology relies primarily on dredging operations which excavate the material from the bottom of waterways. The Corps is testing new dredging technology which may reduce resuspension of sediments by the dredging operation. Pilot plant dredging equipment was tested by the Corps which generated larger quantities of water when compared to conventional equipment, such as the clam shell. The transportation of this 'excess' water adds to the cost of sediment removal. The process developed by the USBM consists of feed material from the barge being pumped through a 4-in line by a centrifugal pump and exiting through a 4-in PVC delivery system. A 1,000-gal fiberglass tank was used to mix the polymer concentrate. The polymer was pumped through a 1-in line using a variable speed progressive cavity pump and introduced to the 4-in feed line prior to passing through a 6-in by 2-ft static mixer. The polymer/feed slurry travels to the clarifying tank where the flocculated material settled to the bottom and allowed 'clean' water to exit the overflow. A pilot scale flocculation unit was operated on-site at the Corps' 'Confined Disposal Facility' in Buffalo, NY.

  15. Hydrogeochemical modelling of an active system of uranium fixation by organic soils and sediments (Needle's Eye, Scotland)

    International Nuclear Information System (INIS)

    Jamet, P.; Schmitt, J.M.; Ledoux, E.; Hooker, P.J.; Escalier des Orres, P.

    1993-01-01

    Uranium accumulation in organic-rich sediments can be closely modelled by assuming that the dominant effect of the uranium-organic matter interaction is the direct or indirect reduction of uranyl compounds to form U(IV) minerals, especially uraninite-pitchblende. Application of this model to the Needle's Eye (Scotland) site where uranium is actively accumulating in Quaternary sediments demonstrates that uranium accumulation is both effective and rapid in environments involving shallow, organic-rich, reducing horizons. The period of uranium deposit formation at Needle's Eye is estimated to be as short as 5000 years. The transport of uranium to the site of deposition by oxidizing groundwaters and the channelling of these oxidizing uraniferous groundwaters are identified as important factors involved in the rapid accumulation of uranium. The regional hydrogeological model indicates that a fault in the area appears to act as a hydraulic screen for the uraniferous groundwaters. On one side of the fault the Quaternary sediments are well drained whilst on the other the flow of groundwater seeps out creating a major flux just at the bottom of the organic-rich layers. The local hydrogeological model shows that the groundwater flow is vertical in this area. A third significant factor in the development of these uranium accumulations is the presence of a significant nearby source of leachable primary uranium. In the case of the Needle's Eye site this is in the form of some thirty 185 ± 20 Ma, pitchblende-bearing veins. 32 refs., 10 figs., 8 tabs

  16. Shallow water table effects on water, sediment, and pesticide transport in vegetative filter strips - Part 2: model coupling, application, factor importance, and uncertainty

    Science.gov (United States)

    Lauvernet, Claire; Muñoz-Carpena, Rafael

    2018-01-01

    Vegetative filter strips are often used for protecting surface waters from pollution transferred by surface runoff in agricultural watersheds. In Europe, they are often prescribed along the stream banks, where a seasonal shallow water table (WT) could decrease the buffer zone efficiency. In spite of this potentially important effect, there are no systematic experimental or theoretical studies on the effect of this soil boundary condition on the VFS efficiency. In the companion paper (Muñoz-Carpena et al., 2018), we developed a physically based numerical algorithm (SWINGO) that allows the representation of soil infiltration with a shallow water table. Here we present the dynamic coupling of SWINGO with VFSMOD, an overland flow and transport mathematical model to study the WT influence on VFS efficiency in terms of reductions of overland flow, sediment, and pesticide transport. This new version of VFSMOD was applied to two contrasted benchmark field studies in France (sandy-loam soil in a Mediterranean semicontinental climate, and silty clay in a temperate oceanic climate), where limited testing of the model with field data on one of the sites showed promising results. The application showed that for the conditions of the studies, VFS efficiency decreases markedly when the water table is 0 to 1.5 m from the surface. In order to evaluate the relative importance of WT among other input factors controlling VFS efficiency, global sensitivity and uncertainty analysis (GSA) was applied on the benchmark studies. The most important factors found for VFS overland flow reduction were saturated hydraulic conductivity and WT depth, added to sediment characteristics and VFS dimensions for sediment and pesticide reductions. The relative importance of WT varied as a function of soil type (most important at the silty-clay soil) and hydraulic loading (rainfall + incoming runoff) at each site. The presence of WT introduced more complex responses dominated by strong interactions in

  17. Effect of high sedimentation rates on surface sediment dynamics and mangrove growth in the Porong River, Indonesia.

    Science.gov (United States)

    Sidik, Frida; Neil, David; Lovelock, Catherine E

    2016-06-15

    Large quantities of mud from the LUSI (Lumpur Sidoarjo) volcano in northeastern Java have been channeled to the sea causing high rates of sediment delivery to the mouth of the Porong River, which has a cover of natural and planted mangroves. This study investigated how the high rates of sediment delivery affected vertical accretion, surface elevation change and the growth of Avicennia sp., the dominant mangrove species in the region. During our observations in 2010-2011 (4-5years after the initial volcanic eruption), very high rates of sedimentation in the forests at the mouth of the river gave rise to high vertical accretion of over 10cmy(-1). The high sedimentation rates not only resulted in reduced growth of Avicennia sp. mangrove trees at the two study sites at the Porong River mouth, but also gave rise to high soil surface elevation gains. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Waste minimization applications at a remediation site

    International Nuclear Information System (INIS)

    Allmon, L.A.

    1995-01-01

    The Fernald Environmental Management Project (FEMP) owned by the Department of Energy was used for the processing of uranium. In 1989 Fernald suspended production of uranium metals and was placed on the National Priorities List (NPL). The site's mission has changed from one of production to environmental restoration. Many groups necessary for producing a product were deemed irrelevant for remediation work, including Waste Minimization. Waste Minimization does not readily appear to be applicable to remediation work. Environmental remediation is designed to correct adverse impacts to the environment from past operations and generates significant amounts of waste requiring management. The premise of pollution prevention is to avoid waste generation, thus remediation is in direct conflict with this premise. Although greater amounts of waste will be generated during environmental remediation, treatment capacities are not always available and disposal is becoming more difficult and costly. This creates the need for pollution prevention and waste minimization. Applying waste minimization principles at a remediation site is an enormous challenge. If the remediation site is also radiologically contaminated it is even a bigger challenge. Innovative techniques and ideas must be utilized to achieve reductions in the amount of waste that must be managed or dispositioned. At Fernald the waste minimization paradigm was shifted from focusing efforts on source reduction to focusing efforts on recycle/reuse by inverting the EPA waste management hierarchy. A fundamental difference at remediation sites is that source reduction has limited applicability to legacy wastes but can be applied successfully on secondary waste generation. The bulk of measurable waste reduction will be achieved by the recycle/reuse of primary wastes and by segregation and decontamination of secondary wastestreams. Each effort must be measured in terms of being economically and ecologically beneficial

  19. WAG 2 remedial investigation and site investigation site-specific work plan/health and safety checklist for the soil and sediment task

    International Nuclear Information System (INIS)

    Holt, V.L.; Burgoa, B.B.

    1993-12-01

    This document is a site-specific work plan/health and safety checklist (WP/HSC) for a task of the Waste Area Grouping 2 Remedial Investigation and Site Investigation (WAG 2 RI ampersand SI). Title 29 CFR Part 1910.120 requires that a health and safety program plan that includes site- and task-specific information be completed to ensure conformance with health- and safety-related requirements. To meet this requirement, the health and safety program plan for each WAG 2 RI ampersand SI field task must include (1) the general health and safety program plan for all WAG 2 RI ampersand SI field activities and (2) a WP/HSC for that particular field task. These two components, along with all applicable referenced procedures, must be kept together at the work site and distributed to field personnel as required. The general health and safety program plan is the Health and Safety Plan for the Remedial Investigation and Site Investigation of Waste Area Grouping 2 at the Oak Ridge National Laboratory, Oak Ridge, Tennessee (ORNL/ER-169). The WP/HSCs are being issued as supplements to ORNL/ER-169

  20. Radionuclide distributions in sediment cores retrieved from marine radioactive waste dumpsites

    International Nuclear Information System (INIS)

    Bowen, V.T.; Livingston, H.D.

    1981-01-01

    The concentrations, distributions and inventories of 55 Fe, 60 Co, 137 Cs, 134 Cs, 238 Pu, sup(239,240)Pu, 241 Am, 244 Cm and 242 Cm were measured in sediment samples collected in 1975-1976 from some Atlantic and Pacific sites used by the United States of America from 1946-1970 to dump solidified radioactive waste. Criteria used to distinguish waste-contaminated sediments from fallout-contaminated sediments include deviations of nuclide concentrations, inventories, internuclide ratios and depth distributions. The detection of nuclides absent from fallout is a further indicator. The data set used in comparing dumpsite sediment radioactivity with non-dumpsite radioactivity comes from a population of 11 North Atlantic cores in the depth range 2000-4000 m. A further set of 19 cores from the central North Pacific provides an interesting contrast to the data set for the shallower sediments closer to the coasts. The principal conclusion drawn from consideration of a large body of data, especially for 15 sediment cores from the Atlantic dumpsite, is that contamination is extremely localized with respect to the sources from which the waste is believed to originate. The majority of cores from both dumpsites are indistinguishable from populations of cores contaminated only by world-wide fallout. Clearly, contaminated sediments from both dumpsites show evidence of the introduction of waste radioactivity below the sediment surface before subsequent redistribution by in-sediment processes. These findings have significance for the selection and monitoring of sites to be used in connection with the ocean disposal of radioactive waste. (author)

  1. New Brunswick Site annual environmental report for calendar year 1991, New Brunswick, New Jersey

    International Nuclear Information System (INIS)

    1992-09-01

    This document describes the environmental monitoring program at the New Brunswick Site (NBS) and surrounding area, implementation of the program, and monitoring results for 1991. The site, near New Brunswick,, New Jersey, is a 5.6-acre vacant, fenced, and grass-covered area. Environmental monitoring of NBS began in 1981 when the site was part of the US Department of Energy's (DOE) Surplus Facilities Management Program. In 1990 responsibility for NBS was transferred to the Formerly Utilized Sites Remedial Action Program (FUSP.4P). FUSRAP is a DOE program to identify and decontaminate or otherwise control sites where residual radioactive materials remain from the,early years of the nation's atomic energy program or from commercial operations causing conditions that Congress has authorized DOE to remedy. The environmental monitoring program at NBS includes sampling networks for radon and thoron in air; external gamma radiation exposure; and radium-226, radium-228, thorium-228, thorium-230, thorium-232, americium-241, cesium-137, plutonium-239, and total uranium in surface water, sediment, and groundwater. Several nonradiological parameters are also measured in groundwater, surface water, and sediments. Monitoring results are compared with applicable Environmental Protection Agency standards, DOE derived concentration guides, dose limits, and other requirements in DOE orders. Environmental standards are established to protect public health and the environment

  2. Turbidity-controlled suspended sediment sampling for runoff-event load estimation

    Science.gov (United States)

    Jack Lewis

    1996-01-01

    Abstract - For estimating suspended sediment concentration (SSC) in rivers, turbidity is generally a much better predictor than water discharge. Although it is now possible to collect continuous turbidity data even at remote sites, sediment sampling and load estimation are still conventionally based on discharge. With frequent calibration the relation of turbidity to...

  3. Seabed ripple morphology and surficial sediment size at the SAX04 experiments near Fort Walton Beach, Florida, fall 2004

    Science.gov (United States)

    Hanes, Daniel M.; Erikson, Li H.; Lescinski, Jamie M.R.; Harney, Jodi N.; Carter, Carissa L.; Hatcher, Gerry A.; Lacy, Jessica R.; Rubin, David M.

    2007-01-01

    Data presented in this report originates from measurements obtained off the Florida coast (fig. 1) as part of the Sediment Acoustics Experiment (SAX04) and Ripples Department Research Initiative (DRI) (Office of Naval Research (ONR), Critical Benthic Environmental Processes and Modeling, Long Range BAA 04-001, Sept. 10, 2003). The aim of this document is to present methods employed to extract data and the resulting measured ripple characteristics (ripple height, wavelength, and orientation) and seabed grain sizes. Application and analysis of the data with respect to hydro- and morphodynamics will be addressed in subsequent reports. Sediment transport in the coastal region is a complex process involving interactions between flow dynamics, sediments, and bedforms. Sediment type and bed geometry directly influence entrainment of sediments into suspension, and at sites where ripples occur (sand formations on the order of several cm high and less than two meter long wavelengths), the understanding of ripple dynamics is an essential component in improving sediment transport models. To gain a better understanding and ability to predict sediment transport, a field study was undertaken to investigate morphology, orientation, and dynamics of ripples on the seafloor. The data obtained from the field campaign also supports an on-going effort to study the effects of ripples on low grazing acoustic penetration into sandy marine sediments for the detection of objects, such as mines (Jackson and others, 2002).

  4. Annual variation in the net longshore sediment transport rate

    CSIR Research Space (South Africa)

    Schoonees, JS

    2000-05-01

    Full Text Available The annual variation in the net long shore sediment transport rates at three South African and at one North African site is investigated. The net rates at these sites, given in the first table, showed large variations. It was found that measurements...

  5. Evaluating sediment transport in flood-driven ephemeral tributaries using direct and acoustic methods.

    Science.gov (United States)

    Stark, K.

    2017-12-01

    One common source of uncertainty in sediment transport modeling of large semi-arid rivers is sediment influx delivered by ephemeral, flood-driven tributaries. Large variations in sediment delivery are associated with these regimes due to the highly variable nature of flows within them. While there are many sediment transport equations, they are typically developed for perennial streams and can be inaccurate for ephemeral channels. Discrete, manual sampling is labor intensive and requires personnel to be on site during flooding. In addition, flooding within these tributaries typically last on the order of hours, making it difficult to be present during an event. To better understand these regimes, automated systems are needed to continuously sample bedload and suspended load. In preparation for the pending installation of an automated site on the Arroyo de los Piños in New Mexico, manual sediment and flow samples have been collected over the summer monsoon season of 2017, in spite of the logistical challenges. These data include suspended and bedload sediment samples at the basin outlet, and stage and precipitation data from throughout the basin. Data indicate a complex system; flow is generated primarily in areas of exposed bedrock in the center and higher elevations of the watershed. Bedload samples show a large coarse-grained fraction, with 50% >2 mm and 25% >6 mm, which is compatible with acoustic measuring techniques. These data will be used to inform future site operations, which will combine direct sediment measurement from Reid-type slot samplers and non-invasive acoustic measuring methods. Bedload will be indirectly monitored using pipe-style microphones, plate-style geophones, channel hydrophones, and seismometers. These instruments record vibrations and acoustic signals from bedload impacts and movement. Indirect methods for measuring of bedload have never been extensively evaluated in ephemeral channels in the southwest United States. Once calibrated

  6. Trace element, semivolatile organic, and chlorinated organic compound concentrations in bed sediments of selected streams at Fort Gordon, Georgia, February-April 2010

    Science.gov (United States)

    Thomas, Lashun K.; Journey, Celeste A.; Stringfield, Whitney J.; Clark, Jimmy M.; Bradley, Paul M.; Wellborn, John B.; Ratliff, Hagan; Abrahamsen, Thomas A.

    2011-01-01

    A spatial survey of streams was conducted from February to April 2010 to assess the concentrations of major ions, selected trace elements, semivolatile organic compounds, organochlorine pesticides, and polychlorinated biphenyls associated with the bed sediments of surface waters at Fort Gordon military installation near Augusta, Georgia. This investigation expanded a previous study conducted in May 1998 by the U.S. Geological Survey, in cooperation with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, that evaluated the streambed sediment quality of selected surface waters at Fort Gordon. The data presented in this report are intended to help evaluate bed sediment quality in relation to guidelines for the protection of aquatic life, and identify temporal trends in trace elements and semivolatile organic compound concentrations at streambed sites previously sampled. Concentrations of 34 major ions and trace elements and 102 semivolatile organic, organochlorine pesticide, and polychlorinated biphenyl compounds were determined in the fine-grained fraction of bed sediment samples collected from 13 of the original 29 sites in the previous study, and 22 additional sites at Fort Gordon. Three of the sites were considered reference sites as they were presumed to be located away from potential sources of contaminants and were selected to represent surface waters flowing onto the fort, and the remaining 32 nonreference sites were presumed to be located within the contamination area at the fort. Temporal trends in trace elements and semivolatile organic compound concentrations also were evaluated at 13 of the 32 nonreference sites to provide an assessment of the variability in the number of detections and concentrations of constituents in bed sediment associated with potential sources, accumulation, and attenuation processes. Major ion and trace element concentrations in fine-grained bed

  7. Deriving a site characterization program from applicable regulations

    International Nuclear Information System (INIS)

    Voegele, M.D.; Younker, J.L.; Alexander, D.H.

    1988-01-01

    The process of deriving a site characterization program from the applicable regulations was approached by the DOE through the use of two basic organizing principles. One organizing principle is a hierarchical structure of questions about regulatory criteria related to the acquisition of site data. This set of questions is called an issues hierarchy, and it provides a topical organizing framework for developing a site characterization program. The second basic organizing principle used by the DOE and its contractors to develop a site characterization program is called performance allocation. For each issue in the issues hierarchy, a resolution strategy is developed. These strategies involve the identification of elements of the disposal system that are relevant to isolation and containment of waste or to radiological safety. It is then possible to identify performance measures and information needed from the site characterization program. This information, coupled with information about confidence in existing data and the confidence required in the data to be obtained, allows the development of testing strategies for field programs

  8. Impact of methane flow through deformable lake sediments on atmospheric release

    Science.gov (United States)

    Scandella, B.; Juanes, R.

    2010-12-01

    Methane is a potent greenhouse gas that is generated geothermally and biologically in lake and ocean sediments. Free gas bubbles may escape oxidative traps and contribute more to the atmospheric source than dissolved methane, but the details of the methane release depend on the interactions between the multiple fluid phases and the deformable porous medium. We present a model and supporting laboratory experiments of methane release through “breathing” dynamic flow conduits that open in response to drops in the hydrostatic load on lake sediments, which has been validated against a high-resolution record of free gas flux and hydrostatic pressure in Upper Mystic Lake, MA. In contrast to previous linear elastic fracture mechanics analysis of gassy sediments, the evolution of gas transport in a deformable compliant sediment is presented within the framework of multiphase poroplasticity. Experiments address how strongly the mode and rate of gas flow, captured by our model, impacts the size of bubbles released into the water column. A bubble's size in turn determines how efficiently it transports methane to the atmosphere, and integrating this effect will be critical to improving estimates of the atmospheric methane source from lakes. Cross-sectional schematic of lake sediments showing two venting sites: one open at left and one closed at right. The vertical release of gas bubbles (red) at the open venting site creates a local pressure drop, which drives both bubble formation from the methane-rich pore water (higher concentrations shaded darker red) and lateral advection of dissolved methane (purple arrows). Even as bubbles in the open site escape, those at the closed site remain trapped.

  9. Membrane-based, sedimentation-assisted plasma separator for point-of-care applications.

    Science.gov (United States)

    Liu, Changchun; Mauk, Michael; Gross, Robert; Bushman, Frederic D; Edelstein, Paul H; Collman, Ronald G; Bau, Haim H

    2013-11-05

    Often, high-sensitivity, point-of-care (POC) clinical tests, such as HIV viral load, require large volumes of plasma. Although centrifuges are ubiquitously used in clinical laboratories to separate plasma from whole blood, centrifugation is generally inappropriate for on-site testing. Suitable alternatives are not readily available to separate the relatively large volumes of plasma from milliliters of blood that may be needed to meet stringent limit-of-detection specifications for low-abundance target molecules. We report on a simple-to-use, low-cost, pump-free, membrane-based, sedimentation-assisted plasma separator capable of separating a relatively large volume of plasma from undiluted whole blood within minutes. This plasma separator consists of an asymmetric, porous, polysulfone membrane housed in a disposable chamber. The separation process takes advantage of both gravitational sedimentation of blood cells and size exclusion-based filtration. The plasma separator demonstrated a "blood in-plasma out" capability, consistently extracting 275 ± 33.5 μL of plasma from 1.8 mL of undiluted whole blood within less than 7 min. The device was used to separate plasma laden with HIV viruses from HIV virus-spiked whole blood with recovery efficiencies of 95.5% ± 3.5%, 88.0% ± 9.5%, and 81.5% ± 12.1% for viral loads of 35,000, 3500, and 350 copies/mL, respectively. The separation process is self-terminating to prevent excessive hemolysis. The HIV-laden plasma was then injected into our custom-made microfluidic chip for nucleic acid testing and was successfully subjected to reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP), demonstrating that the plasma is sufficiently pure to support high-efficiency nucleic acid amplification.

  10. Dynamics of sediment carbon stocks across intertidal wetland habitats of Moreton Bay, Australia.

    Science.gov (United States)

    Hayes, Matthew A; Jesse, Amber; Hawke, Bruce; Baldock, Jeff; Tabet, Basam; Lockington, David; Lovelock, Catherine E

    2017-10-01

    Coastal wetlands are known for high carbon storage within their sediments, but our understanding of the variation in carbon storage among intertidal habitats, particularly over geomorphological settings and along elevation gradients, is limited. Here, we collected 352 cores from 18 sites across Moreton Bay, Australia. We assessed variation in sediment organic carbon (OC) stocks among different geomorphological settings (wetlands within riverine settings along with those with reduced riverine influence located on tide-dominated sand islands), across elevation gradients, with distance from shore and among habitat and vegetation types. We used mid-infrared (MIR) spectroscopy combined with analytical data and partial least squares regression to quantify the carbon content of ~2500 sediment samples and provide fine-scale spatial coverage of sediment OC stocks to 150 cm depth. We found sites in river deltas had larger OC stocks (175-504 Mg/ha) than those in nonriverine settings (44-271 Mg/ha). Variation in OC stocks among nonriverine sites was high in comparison with riverine and mixed geomorphic settings, with sites closer to riverine outflow from the east and south of Moreton Bay having higher stocks than those located on the sand islands in the northwest of the bay. Sediment OC stocks increased with elevation within nonriverine settings, but not in riverine geomorphic settings. Sediment OC stocks did not differ between mangrove and saltmarsh habitats. OC stocks did, however, differ between dominant species across the research area and within geomorphic settings. At the landscape scale, the coastal wetlands of the South East Queensland catchments (17,792 ha) are comprised of approximately 4,100,000-5,200,000 Mg of sediment OC. Comparatively high variation in OC storage between riverine and nonriverine geomorphic settings indicates that the availability of mineral sediments and terrestrial derived OC may exert a strong influence over OC storage potential across

  11. Sedimentation studies at MUDA catchment area, Kedah, Malaysia

    International Nuclear Information System (INIS)

    Kamarudin Samuding; Juhari Yusuf; Wan Abdul Aziz; Juhari Latiff

    2000-01-01

    A study on the sediment size distribution and determination of sediment density profile in the selected area of Muda dam catchment area, Kedah is presented. The objective of the study was to establish a base line data of the input sedimentation with regards to the effects of development within the catchment in the future. Three main sampling locations were identified namely at Sungai Teliang, Sungai Muda and Muda reservoir. Measurement of sediment thickness was performed by using nuclear gauges i.e. direct transmission and backscattering methods. Results showed that the grain size distribution of sediment ranges from gravel to clay sizes. In the reservoir and downstream of the river, most of the samples studied consisting of fine sediment i.e silt and clay sizes (<63,um). However, sediment distribution in the upstream section of Sungai Teliang mainly consist of fine to coarse sand. Sediment density profiles in the reservoir showed little changes, whereas bed sediment profiles in the river cross-sectional areas exhibit some changes. The results also showed that thickness of bedload sediment were different from one location to another, in which the thickness may achieve up to 0.75 metre in some areas. Based on the sediment distribution profile analysis, the study site could be divided into two parts comprising of dynamic area (region) covering selected locations along the river and deposited sediment in the reservoir. Basic information derived from this study may provide as one of the important inputs for the MADA reservoir management authority in monitoring, supervising y and identifying rate and source of sediment in the catchment area

  12. Clearing the waters: Evaluating the need for site-specific field fluorescence corrections based on turbidity measurements

    Science.gov (United States)

    Saraceno, John F.; Shanley, James B.; Downing, Bryan D.; Pellerin, Brian A.

    2017-01-01

    In situ fluorescent dissolved organic matter (fDOM) measurements have gained increasing popularity as a proxy for dissolved organic carbon (DOC) concentrations in streams. One challenge to accurate fDOM measurements in many streams is light attenuation due to suspended particles. Downing et al. (2012) evaluated the need for corrections to compensate for particle interference on fDOM measurements using a single sediment standard in a laboratory study. The application of those results to a large river improved unfiltered field fDOM accuracy. We tested the same correction equation in a headwater tropical stream and found that it overcompensated fDOM when turbidity exceeded ∼300 formazin nephelometric units (FNU). Therefore, we developed a site-specific, field-based fDOM correction equation through paired in situ fDOM measurements of filtered and unfiltered streamwater. The site-specific correction increased fDOM accuracy up to a turbidity as high as 700 FNU, the maximum observed in this study. The difference in performance between the laboratory-based correction equation of Downing et al. (2012) and our site-specific, field-based correction equation likely arises from differences in particle size distribution between the sediment standard used in the lab (silt) and that observed in our study (fine to medium sand), particularly during high flows. Therefore, a particle interference correction equation based on a single sediment type may not be ideal when field sediment size is significantly different. Given that field fDOM corrections for particle interference under turbid conditions are a critical component in generating accurate DOC estimates, we describe a way to develop site-specific corrections.

  13. Electrokinetic remediation of plutonium-contaminated nuclear site wastes: Results from a pilot-scale on-site trial

    International Nuclear Information System (INIS)

    Agnew, Kieran; Cundy, Andrew B.; Hopkinson, Laurence; Croudace, Ian W.; Warwick, Phillip E.; Purdie, Philip

    2011-01-01

    This paper examines the field-scale application of a novel low-energy electrokinetic technique for the remediation of plutonium-contaminated nuclear site soils, using soil wastes from the Atomic Weapons Establishment (AWE) Aldermaston site, Berkshire, UK as a test medium. Soils and sediments with varying composition, contaminated with Pu through historical site operations, were electrokinetically treated at laboratory-scale with and without various soil pre-conditioning agents. Results from these bench-scale trials were used to inform a larger on-site remediation trial, using an adapted containment pack with battery power supply. 2.4 m 3 (ca. 4 tonnes) of Pu-contaminated soil was treated for 60 days at a power consumption of 33 kW h/m 3 , and then destructively sampled. Radiochemical data indicate mobilisation of Pu in the treated soil, and migration (probably as a negatively charged Pu-citrate complex) towards the anodic compartment of the treatment cell. Soil in the cathodic zone of the treatment unit was remediated to a level below free-release disposal thresholds (1.7 Bq/g, or <0.4 Bq/g above background activities). The data show the potential of this method as a low-cost, on-site tool for remediation of radioactively contaminated soils and wastes which can be operated remotely on working sites, with minimal disruption to site infrastructure or operations.

  14. Distribution and partitioning of heavy metals in estuarine sediment cores and implications for the use of sediment quality standards

    Directory of Open Access Journals (Sweden)

    K. L. Spencer

    2002-01-01

    Full Text Available Total metal concentrations in surface sediments and historically contaminated sediments were determined in sediment cores collected from three estuaries (Thames, Medway and Blackwater in south-east England. The partitioning behaviour of metals in these sediments was also determined using a sequential extraction scheme. These data were then compared with sediment quality values (SQVs to determine the potential ecotoxicological risk to sediment dwelling organisms. When total metal concentrations in surface sediments are examined, no risk to biota in any of the estuaries is indicated. However, when historically contaminated sediments at depth are also considered, risks to biota are apparent and are greatest for the Thames, followed by the Medway and then the Blackwater. This suggests that regulatory authorities should examine vertical metal profiles, particularly in estuaries that are experiencing low sediment accumulation rates where historically contaminated sediments are in the shallow sub-surface zone and where erosion or dredging activities may take place. When metal partitioning characteristics are also considered, the risk to biota is comparable for the Medway and the Blackwater with the potentially bioavailable fraction presenting no ecotoxicological risk. Conversely, over 70% of metals are labile in the Thames Estuary sediments and toxic effects are probable. This suggests that the application of SQVs using total sediment metal concentrations may over- or under-estimate the risk to biota in geochemically dissimilar estuarine sediments. Keywords: sediment quality values, estuarine sediments, metal contamination, partitioning, sequential extraction

  15. Bacterial GDGTs in Holocene sediments and catchment soils of a high Alpine lake: application of the MBT/CBT-paleothermometer

    Directory of Open Access Journals (Sweden)

    H. Niemann

    2012-05-01

    Full Text Available A novel proxy for continental mean annual air temperature (MAAT and soil pH, the MBT/CBT-paleothermometer, is based on the temperature (T and pH-dependent distribution of specific bacterial membrane lipids (branched glycerol dialkyl glycerol tetraethers – GDGTs in soil organic matter. Here, we tested the applicability of the MBT/CBT-paleothermometer to sediments from Lake Cadagno, a high Alpine lake in southern Switzerland with a small catchment of 2.4 km2. We analysed the distribution of bacterial GDGTs in catchment soils and in a radiocarbon-dated sediment core from the centre of the lake, covering the past 11 000 yr. The distribution of bacterial GDGTs in the catchment soils is very similar to that in the lake's surface sediments, indicating a common origin of the lipids. Consequently, their transfer from the soils into the sediment record seems undisturbed, probably without any significant alteration of their distribution through in situ production in the lake itself or early diagenesis of branched GDGTs. The MBT/CBT-inferred MAAT estimates from soils and surface sediments are in good agreement with instrumental values for the Lake Cadagno region (~0.5 °C. Moreover, downcore MBT/CBT-derived MAAT estimates match in timing and magnitude other proxy-based T reconstructions from nearby locations for the last two millennia. Major climate anomalies recorded by the MBT/CBT-paleothermometer are, for instance, the Little Ice Age (~14th to 19th century and the Medieval Warm Period (MWP, ~9th to 14th century. Together, our observations indicate the quantitative applicability of the MBT/CBT-paleothermometer to Lake Cadagno sediments. In addition to the MWP, our lacustrine paleo T record indicates Holocene warm phases at about 3, 5, 7 and 11 kyr before present, which agrees in timing with other records from both the Alps and the sub-polar North-East Atlantic Ocean. The good temporal match of the warm periods determined

  16. The use of modeling and suspended sediment concentration measurements for quantifying net suspended sediment transport through a large tidally dominated inlet

    Science.gov (United States)

    Erikson, Li H.; Wright, Scott A.; Elias, Edwin; Hanes, Daniel M.; Schoellhamer, David H.; Largier, John; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Sediment exchange at large energetic inlets is often difficult to quantify due complex flows, massive amounts of water and sediment exchange, and environmental conditions limiting long-term data collection. In an effort to better quantify such exchange this study investigated the use of suspended sediment concentrations (SSC) measured at an offsite location as a surrogate for sediment exchange at the tidally dominated Golden Gate inlet in San Francisco, CA. A numerical model was calibrated and validated against water and suspended sediment flux measured during a spring–neap tide cycle across the Golden Gate. The model was then run for five months and net exchange was calculated on a tidal time-scale and compared to SSC measurements at the Alcatraz monitoring site located in Central San Francisco Bay ~ 5 km from the Golden Gate. Numerically modeled tide averaged flux across the Golden Gate compared well (r2 = 0.86, p-value

  17. Factors Effecting Adsorption of 137 Cs in Marine Sediment Samples in Marine Sediment Samples from the Upper Gulf of Thailand

    International Nuclear Information System (INIS)

    Saengkul, C.; Sawangwong, P.; Pakkong, P.

    2014-01-01

    Contamination of 137 Cs in sediment is a far more serious problem than in water because sediment is a main transport factor of 137 Cs to the aquatic environmental. Most of 137 Cs in water could be accumulated in sediment which has direct effect to benthos. This study focused on factors effecting the adsorption of 137Cs in marine sediment samples collected from four different estuary sites to assess the transfer direction of 137 Cs from water to sediment that the study method by treat 137 Cs into seawater and mixed with different sediment samples for 4 days. The result indicated that properties of marine sediment (cation exchange capacity (CEC), organic matter, clay content, texture, type of clay mineral and size of soil particle) had effects on 137 Cs adsorption. CEC and clay content correlated positively with the accumulation of 137 Cs in the marine sediment samples. On the other hand, organic matter in sediment correlated negatively with the accumulation of 137 Cs in samples. The study of environmental effects (pH and potassium) found that the 137 Cs adsorption decreased when concentration of potassium increased. The pH effect is still unclear in this study because the differentiation of pH levels (6, 7, 8.3) did not have effects on 137 Cs adsorption in the samples.

  18. Improving the reliability of open-cycle water systems: Application of biofouling surveillance and control techniques to sediment and corrosion fouling at nuclear power plants

    International Nuclear Information System (INIS)

    Johnson, K.I.; Neitzel, D.A.

    1987-03-01

    Biofouling surveillance and control techniques are evaluated for their applicability to sediment and corrosion fouling and suggestions are given to improve their effectiveness. Alternate techniques to better detect and control sedimentation and corrosion are also evaluated. Environmental conditions that allow biofouling, sedimentation, and corrosion to occur are summarized. A correlation between sediment and corrosion is identified and the causes are described. Environmental regulations, especially those in the Clean Water Act of 1977, are reviewed to identify those that may limit or prevent the use of surveillance and control techniques described in this report. Flow velocity is the major design factor that determines whether or not biofouling, sedimentation, and corrosion will occur. Monitoring flow conditions can provide early warning of conditions that will allow fouling to occur. Visual inspection is the most common and most effective technique for identifying the cause and extent of fouling in the open-cycle water system. Most biofouling control techniques in current use are not effective against sediment and corrosion. Frequent, high-velocity flushing of cooling loops may effectively remove sediment and reduce under-sediment corrosion. Alternate biocide treatments such as targeted chlorination or the use of ozone or 2,2-dibromo-3-nitrilo propionamide (DBNPA) may also be effective in reducing under-sediment corrosion

  19. Growth and mortality of coral transplants (Pocillopora damicornis) along a range of sediment influence in Maui, Hawai'i

    Science.gov (United States)

    Piniak, G.A.; Brown, E.K.

    2008-01-01

    Fragments of the lace coral Pocillopora damicornis (Linnaeus, 1758) were transplanted to four sites on the south-central coast of Maui, Hawai'i, to examine coral growth over a range of expected sediment influence. Corals remained in situ for 11 months and were recovered seasonally for growth measurements using the buoyant weight technique. Average sediment trap accumulation rates ranged from 11 to 490 mg cm-2 day-1 and were greater at the wave-exposed reef site than at the protected harbor sites. Coral growth was highest at the donor site and was higher in the summer than in the winter. A stepwise linear regression found significant effects of sediment trap accumulation and light on growth rates, but the partial correlation coefficients suggest that these factors may be only secondary controls on growth. This study did not show a clear link between coral growth and sediment load. This result may be due, in part, to covariation of sediment load with wave exposure and the inability of trap accumulation rates to integrate all sediment effects (e.g., turbidity) that can affect coral growth. ?? 2008 by University of Hawai'i Press. All rights reserved.

  20. Sedimentation in the Three Gorges Dam and the future trend of Changjiang (Yangtze River sediment flux to the sea

    Directory of Open Access Journals (Sweden)

    Guogang Li

    2009-11-01

    Full Text Available The Three Gorges Dam (TGD on the upper Changjiang (Yangtze River, China, disrupts the continuity of Changjiang sediment delivery to downstream and coastal areas. In this study, which was based on 54 years of annual water and sediment data from the mainstream and major tributaries of Changjiang, sediment deposition induced by the TGD in 2003–2008 was quantified. Furthermore, we determined the theoretical trapping efficiency of the cascade reservoir upstream of the TGD. Its impact on Changjiang sediment flux in the coming decades is discussed. Results show that about 172 million tons (Mt of sediment was trapped annually by the TGD in 2003–2008, with an averaged trapping efficiency of 75%. Most of the total sediment deposition, as induced by the TGD (88%, accumulated within the region between the TGD site and Cuntan. However, significant siltation (12% of the total sediment deposition also occurred upstream of Cuntan as a consequence of the upstream extended backwater region of the TGD. Additionally, the Changjiang sediment flux entered a third downward step in 2001, prior to operation of the TGD. This mainly resulted from sediment reduction in the Jinshajiang tributary since the late 1990s. As the cascade reservoir is put into full operation, it could potentially trap 91% of the Jinshajiang sediment discharge and, therefore, the Jinshajiang sediment discharge would most likely further decrease to 14 Mt/yr in the coming decades. Consequently, the Changjiang sediment flux to the sea is expected to continuously decrease to below 90 Mt/yr in the near future, or only 18% of the amount observed in the 1950s. In the presence of low sediment discharge, profound impacts on the morphology of estuary, delta and coastal waters are expected.

  1. Sediment-associated aliphatic and aromatic hydrocarbons in coastal British Columbia, Canada: Concentrations, composition, and associated risks to protected sea otters

    International Nuclear Information System (INIS)

    Harris, Kate A.; Yunker, Mark B.; Dangerfield, Neil; Ross, Peter S.

    2011-01-01

    Sediment-associated hydrocarbons can pose a risk to wildlife that rely on benthic marine food webs. We measured hydrocarbons in sediments from the habitat of protected sea otters in coastal British Columbia, Canada. Alkane concentrations were dominated by higher odd-chain n-alkanes at all sites, indicating terrestrial plant inputs. While remote sites were dominated by petrogenic polycyclic aromatic hydrocarbons (PAHs), small harbour sites within sea otter habitat and sites from an urban reference area reflected weathered petroleum and biomass and fossil fuel combustion. The partitioning of hydrocarbons between sediments and adjacent food webs provides an important exposure route for sea otters, as they consume ∼25% of their body weight per day in benthic invertebrates. Thus, exceedences of PAH sediment quality guidelines designed to protect aquatic biota at 20% of the sites in sea otter habitat suggest that sea otters are vulnerable to hydrocarbon contamination even in the absence of catastrophic oil spills. - Highlights: → Sediment hydrocarbon signatures differed between remote and impacted coastal sites. → A natural background comprised terrestrial plant alkanes and petrogenic PAHs. → Impacted sites reflected a history of petrogenic and pyrogenic hydrocarbon inputs. → Hydrocarbons at some sites exceeded guidelines for the protection of aquatic life. → Protected sea otters may thus be at risk as they rely primarily on benthic prey. - Anthropogenically-derived hydrocarbons in coastal sediments in British Columbia may pose a risk to protected sea otters.

  2. Selected trace-element and organic contaminants in the streambed sediments of the Potomac River Basin, August 1992

    Science.gov (United States)

    Gerhart, James M.; Blomquist, Joel D.

    1995-01-01

    This report describes the occurrence and distribution of five selected contaminants in streambed sediments at 22 stream sites in the Potomac River Basin. Lead, mercury, and total DDT (dichlorodiphenyltrichloroethane) were detected at all sites, and chlordane and total PCB's (polychlorinated biphenyls) were detected at most sites. At six sites, streambed-sediment concentrations of contaminants were detected at levels with the potential to cause frequent adverse effects on aquatic organisms that live in the sediments. Chlordane was detected at these high levels at sampling sites on the Anacostia River, the North Branch Potomac River, Bull Run, and Accotink Creek; mercury was detected at these levels at sites on the South River and the South Fork Shenandoah River; and total PCB's were detected at these levels at the site on the South Fork Shenandoah River. The highest concentrations of all five contaminants generally occurred at sampling sites downstream from areas with industrial plants, urban centers, or orchard and agricultural activity. The occurrence of these contaminants in streambed sediments of the Potomac River Basin is of concern because the contaminants (1) are environmentally persistent, (2) are available for downstream transport during high streamflow periods, and (3) have the potential to cause adverse effects on the health of aquatic organisms and humans through bioaccumulation.

  3. 100 Area Columbia River sediment sampling

    International Nuclear Information System (INIS)

    Weiss, S.G.

    1993-01-01

    Forty-four sediment samples were collected from 28 locations in the Hanford Reach of the Columbia River to assess the presence of metals and man-made radionuclides in the near shore and shoreline settings of the Hanford Site. Three locations were sampled upriver of the Hanford Site plutonium production reactors. Twenty-two locations were sampled near the reactors. Three locations were sampled downstream of the reactors near the Hanford Townsite. Sediment was collected from depths of 0 to 6 in. and between 12 to 24 in. below the surface. Samples containing concentrations of metals exceeding the 95 % upper threshold limit values (DOE-RL 1993b) are considered contaminated. Contamination by arsenic, chromium, copper, lead, and zinc was found. Man-made radionuclides occur in all samples except four collected opposite the Hanford Townsite. Man-made radionuclide concentrations were generally less than 1 pCi/g

  4. 100 Area Columbia River sediment sampling

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, S.G. [Westinghouse Hanford Co., Richland, WA (United States)

    1993-09-08

    Forty-four sediment samples were collected from 28 locations in the Hanford Reach of the Columbia River to assess the presence of metals and man-made radionuclides in the near shore and shoreline settings of the Hanford Site. Three locations were sampled upriver of the Hanford Site plutonium production reactors. Twenty-two locations were sampled near the reactors. Three locations were sampled downstream of the reactors near the Hanford Townsite. Sediment was collected from depths of 0 to 6 in. and between 12 to 24 in. below the surface. Samples containing concentrations of metals exceeding the 95 % upper threshold limit values (DOE-RL 1993b) are considered contaminated. Contamination by arsenic, chromium, copper, lead, and zinc was found. Man-made radionuclides occur in all samples except four collected opposite the Hanford Townsite. Man-made radionuclide concentrations were generally less than 1 pCi/g.

  5. Characterization of sediment transport upstream and downstream from Lake Emory on the Little Tennessee River near Franklin, North Carolina, 2014–15

    Science.gov (United States)

    Huffman, Brad A.; Hazell, William F.; Oblinger, Carolyn J.

    2017-09-06

    Federal, State, and local agencies and organizations have expressed concerns regarding the detrimental effects of excessive sediment transport on aquatic resources and endangered species populations in the upper Little Tennessee River and some of its tributaries. In addition, the storage volume of Lake Emory, which is necessary for flood control and power generation, has been depleted by sediment deposition. To help address these concerns, a 2-year study was conducted in the upper Little Tennessee River Basin to characterize the ambient suspended-sediment concentrations and suspended-sediment loads upstream and downstream from Lake Emory in Franklin, North Carolina. The study was conducted by the U.S. Geological Survey in cooperation with Duke Energy. Suspended-sediment samples were collected periodically, and time series of stage and turbidity data were measured from December 2013 to January 2016 upstream and downstream from Lake Emory. The stage data were used to compute time-series streamflow. Suspended-sediment samples, along with time-series streamflow and turbidity data, were used to develop regression models that were used to estimate time-series suspended-sediment concentrations for the 2014 and 2015 calendar years. These concentrations, along with streamflow data, were used to compute suspended-sediment loads. Selected suspended-sediment samples were collected for analysis of particle-size distribution, with emphasis on high-flow events. Bed-load samples were also collected upstream from Lake Emory.The estimated annual suspended-sediment loads (yields) for the upstream site for the 2014 and 2015 calendar years were 27,000 short tons (92 short tons per square mile) and 63,300 short tons (215 short tons per square mile), respectively. The annual suspended-sediment loads (yields) for the downstream site for 2014 and 2015 were 24,200 short tons (75 short tons per square mile) and 94,300 short tons (292 short tons per square mile), respectively. Overall, the

  6. Argonne National Laboratory-east site environmental report for calendar year 1988

    International Nuclear Information System (INIS)

    Golchert, N.W.; Duffy, T.L.

    1989-04-01

    The results of the environmental monitoring program at Argonne National Laboratory (ANL) for 1988 are presented and discussed. Sample collections were made on the site, at the site boundary, and off the ANL site for comparison purposes. Measurements were made for a variety of radionuclides in air, surface water, ground water, soil, grass, bottom sediment, and milk. Samples were also analyzed for a variety of chemical constituents in surface water, ground water, and ANL effluent water. External penetrating radiation doses were also measured. The potential for radiation exposure to off-site population groups is estimated. The results of the program are interpreted in terms of the origin of the radioactive and chemical substances and are compared with applicable environmental quality standards. A United States Department of Energy dose calculation methodology, is used in this report. 28 refs., 9 figs., 81 tabs

  7. Determining Sediment Sources in the Anacostia River Watershed

    Science.gov (United States)

    Devereux, O. H.; Needelman, B. A.; Prestegaard, K. L.; Gellis, A. C.; Ritchie, J. C.

    2005-12-01

    Suspended sediment is a water-quality problem in the Chesapeake Bay. This project is designed to identify sediment sources in an urban watershed, the Northeast Branch of the Anacostia River (in Washington, D.C. and Maryland - drainage area = 188.5 km2), which delivers sediment directly to the Bay. This watershed spans two physiographic regions - the Piedmont and Coastal Plain. Bank sediment and suspended-sediment deposits were characterized using the following techniques: radionuclide (Cs-137) analysis by gamma ray spectrometry, trace-element analysis by ICP-MS, clay mineralogy by XRD, and particle-size analysis by use of a laser particle-size analyzer. Sampling of bank and suspended sediment was designed to: a) characterize tributary inputs from both Piedmont and Coastal Plain sources, and b) differentiate tributary inputs from bank erosion along the main stem of the Northeast Branch. Thirteen sample sites were chosen that represent tributary source areas of each physiographic region and the main stem where mixing occurs. Surface samples of the banks were compared to overbank deposits from a ten year storm (a proxy for the suspended sediments). Fingerprint components are selected from these data. Cesium-137 concentrations were analyzed for bank and overbank deposits for each physiographic region. No clear differences were seen between the two physiographic regions. Significant differences were observed between upland tributaries and the main stem of the Anacostia River. The average activity of Cs-137 for the tributaries was 5.4 bq/kg and the average for the main stem was 1.1 bq/kg. This suggests that there is significant erosion and storage of sediment in the tributaries. The low activity from Cs-137 in the main stem suggests a lack of storage of sediment along the main stem of the river. For the trace-element data, we focused on elements that showed significant variation among the sites. For the bank sediment, these elements include: Sr, V, Y, Ce, and Nd. For the

  8. Biochemical parameters in Tubifex tubifex as an integral part of complex sediment toxicity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Smutna, M.; Hilscherova, K.; Paskova, V. [Masaryk Univ., Brno (CZ). RECETOX (Research Centre for Environmental Chemistry and Ecotoxicology); Marsalek, B [Czech Academy of Science, Brno (Czech Republic). Centre for Cyanobacteria and their Toxins

    2008-06-15

    Background, aim, and scope Restoration of lakes and reservoirs with extensive cyanobacterial water bloom often requires evaluation of the sediment quality. Next to the chemical analysis of known pollutants, sediment bioassays should be employed to assess toxicity of the present contaminants and to make predictions of associated risk. Brno reservoir in the Czech Republic is a typical example of water bodies with long-term problems concerning cyanobacterial water blooms. Comprehensive assessment of reservoir sediment quality was conducted since successful reservoir restoration might require sediment removal. An important part of this survey focused on an examination of the utility of Tubifex tubifex and its sublethal biochemical markers for the assessment of direct sediment toxicity. Materials and methods This complex study included chemical analysis of contaminants (heavy metals, organic pollutants), ecotoxicity testing of sediment elutriates (tests with Daphnia magna, Pseudomonas putida, Sinapis alba, Scenedesmus subspicatus), and other parameters. We have tested in more detail the applicability of T. tubifex as a test organism for direct evaluation of contact sediment toxicity. Survival tests after 14 days of exposure were complemented by an assessment of parameters serving as biomarkers for sublethal effects [such as total glutathione content (GSH), activities of the enzymes glutathione transferase (GST), glutathione peroxidase (GPx), and glutathione reductase (GR)]. The data matrix was subjected to multivariate analysis to interpret relationships between different parameters and possible differences among locations. Results The multivariate statistical techniques helped to clearly identify the more contaminated upstream sites and separate them from the less contaminated and reference samples. The data document closer relationships of the detected sediment contamination with results of direct sediment exposure in the T. tubifex test regarding mortality but namely

  9. Sediment Transport Over Run-of-River Dams

    Science.gov (United States)

    O'Brien, M.; Magilligan, F. J.; Renshaw, C. E.

    2016-12-01

    Dams have numerous documented effects that can degrade river habitat downstream. One significant effect of large dams is their ability to trap sediment delivered from upstream. This trapping can alter sediment transport and grain size downstream - effects that often motivate dam removal decisions. However, recent indirect observations and modeling studies indicate that small, run-of-river (ROR) dams, which do not impede discharge, may actually leak sediment downstream. However, there are no direct measurements of sediment flux over ROR dams. This study investigates flow and sediment transport over four to six different New England ROR dams over a summer-fall field season. Sediment flux was measured using turbidity meters and tracer (RFID) cobbles. Sediment transport was also monitored through an undammed control site and through a river where two ROR dams were recently removed. These data were used to predict the conditions that contribute to sediment transport and trapping. Year 1 data show that tracer rocks of up to 61 mm were transported over a 3 m ROR dam in peak flows of 84% of bankfull stage. These tracer rocks were transported over and 10 m beyond the dam and continue to move downstream. During the same event, comparable suspended sediment fluxes of up to 81 g/s were recorded both upstream and downstream of the dam at near-synchronous timestamps. These results demonstrate the potential for sediment transport through dammed rivers, even in discharge events that do not exceed bankfull. This research elucidates the effects of ROR dams and the controls on sediment transport and trapping, contributions that may aid in dam management decisions.

  10. 40K in the Black Sea: a proxy to estimate biogenic sedimentation

    International Nuclear Information System (INIS)

    Gulin, S.B.; Gulina, L.V.; Sidorov, I.G.; Proskurnin, V.Yu.; Duka, M.S.; Moseichenko, I.N.; Rodina, E.A.

    2014-01-01

    An approach to estimate the rate of biogenic sedimentation in the Black Sea using the naturally occurring radionuclide 40 K has been considered. It allows assessment of the contribution of suspended matter of biological origin to the overall sediment accumulation in the Black Sea coastal, shelf and deep-water areas. Based upon this method, a relationship between the biogenic fraction of the seabed sediments and the water depth has been established with a view to differentiating the contributions of allochthonous and autochthonous suspended matter to the sedimentation rate. Overall, 40 K can be considered as an easily applicable proxy to assess sedimentation rate of biogenic fraction of particulate matter in marine environments. - Highlights: • 40 K-based approach was developed to assess biogenic sedimentation in the Black Sea. • 40 K-derived relationship between biogenic sedimentation and water depth was traced. • 40 K is an easily applicable proxy to estimate rate of biogenic sedimentation in sea

  11. Modern processes of sediment formation in Lake Towuti, Indonesia, as derived from the composition of lake surface sediments

    Science.gov (United States)

    Hasberg, Ascelina; Melles, Martin; Morlock, Marina; Vogel, Hendrik; Russel, James M.; Bijaksana, Satria

    2016-04-01

    In summer 2015, a drilling operation funded by the International Continental Scientific Drilling Program (ICDP) was conducted at Lake Towuti (2.75°S, 121.5°E), the largest tectonically formed lake (surface area: 561 km²) of the Republic Indonesia. The Towuti Drilling Project (TDP) recovered more than 1000 meters of sediment core from three sites. At all three sites replicate cores down to 133, 154, and 174 m below lake floor have penetrated the entire lake sediment record, which is expected to comprise the past ca. 650.000 years continuously. Lake Towutís sediment record thus can provide unique information for instance concerning the climatic and environmental history in the Indo-Pacific-Warm-Pool (IPWP) and concerning the evolutionary biology in SE Asia. For a better understanding of the palaeoenvironmental proxies to be analyzed on the drill cores, the modern processes of sediment formation in the lake and in its catchment - under known environmental conditions - were investigated on a set of 84 lake sediment surface samples. Sampling was conducted by grab sampler (UWITEC Corp., Austria) in a grid of 1 to 4 km resolution that covers the entire lake. The samples were analyzed for inorganic geochemical composition (XRF powder scans and ICP-MS), magnetic susceptibility (Kappabridge), grain-size distribution (laser scanner), biogenic components (smear-slide analyses), biogenic silica contents (leaching), and carbonate, total organic carbon (TOC), nitrogen (TN), and sulfur (TS) concentrations (elemental analyzer). The sediments close to the lake shores and in front of the major river inlets are characterized by mean grain sizes coarser than average and high magnetic susceptibilities presented by high ratios of Cr, Ni, Co, and Zr. This reflects higher energies due to wave action and fluvial sediment supply, as well as the occurrence of magnetic minerals particularly in the sand and gravel fractions of the sediments. In regions of deeper waters and more distal to

  12. Use of spatially distributed time-integrated sediment sampling networks and distributed fine sediment modelling to inform catchment management.

    Science.gov (United States)

    Perks, M T; Warburton, J; Bracken, L J; Reaney, S M; Emery, S B; Hirst, S

    2017-11-01

    Under the EU Water Framework Directive, suspended sediment is omitted from environmental quality standards and compliance targets. This omission is partly explained by difficulties in assessing the complex dose-response of ecological communities. But equally, it is hindered by a lack of spatially distributed estimates of suspended sediment variability across catchments. In this paper, we demonstrate the inability of traditional, discrete sampling campaigns for assessing exposure to fine sediment. Sampling frequencies based on Environmental Quality Standard protocols, whilst reflecting typical manual sampling constraints, are unable to determine the magnitude of sediment exposure with an acceptable level of precision. Deviations from actual concentrations range between -35 and +20% based on the interquartile range of simulations. As an alternative, we assess the value of low-cost, suspended sediment sampling networks for quantifying suspended sediment transfer (SST). In this study of the 362 km 2 upland Esk catchment we observe that spatial patterns of sediment flux are consistent over the two year monitoring period across a network of 17 monitoring sites. This enables the key contributing sub-catchments of Butter Beck (SST: 1141 t km 2 yr -1 ) and Glaisdale Beck (SST: 841 t km 2 yr -1 ) to be identified. The time-integrated samplers offer a feasible alternative to traditional infrequent and discrete sampling approaches for assessing spatio-temporal changes in contamination. In conjunction with a spatially distributed diffuse pollution model (SCIMAP), time-integrated sediment sampling is an effective means of identifying critical sediment source areas in the catchment, which can better inform sediment management strategies for pollution prevention and control. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Heavy metals in sediments, mussels and oysters from Trinidad and Venezuela

    International Nuclear Information System (INIS)

    Rojas Astudillo, L. de; Chang Yen, I.; Bekele, I.

    2005-01-01

    The Gulf of Paria is bordered by both Trinidad and Venezuela, from which various metallic pollutants and other contaminants can originate. The Gulf is still a significant source of fish, crabs and shellfish for human consumption to both countries, where concerns over the quality of this marine environment have been long expressed but never properly addressed. In addition, the circulatory current patterns in the Gulf ensure that contaminants originating from either country are likely to affect both countries eventually. Heavy metals were determined in oysters (Crassostrea rhizophorae and C. virginica), green mussels (Perna viridis) and sediments from the Gulf of Paria. Samples were obtained at four sites in Trinidad and three sites in Venezuela in the Gulf of Paria, in addition to comparative samples collected from three sites on the north coast of Venezuela. Edible tissues of twelve shellfish from each location were blended and aliquots digested with concentrated nitric acid, for extraction of cadmium, chromium, copper, lead, nickel and zinc. The solutions were analysed by flame atomic absorption spectroscopy. Mercury was extracted with a mixture of nitric, hydrochloric and sulphuric acids and determined by cold vapour atomic absorption. Sediments were oven-dried at 60 0 C, before being similarly extracted. Results showed that mercury in sediments at all sites in Trinidad and Venezuela exceeded NOAA and Canadian sediment quality guidelines, while cadmium, copper, nickel, lead and zinc also exceeded these guidelines at several sites. Heavy metal levels in oysters and green mussels varied widely with location. However, oysters from the Gulf of Paria contained significantly higher mean levels of cadmium, copper, nickel and zinc than those from the north coast of Venezuela, but this difference was not apparent in mussels. Cadmium, mercury and zinc in sediments were significantly correlated with those of mussels, but not of oysters, in which copper and zinc at several

  14. Bioleaching of heavy metal polluted sediment: influence of sediment properties. Pt. 2

    Energy Technology Data Exchange (ETDEWEB)

    Loeser, C. [Technische Universitaet Dresden, Institut fuer Lebensmittel- und Bioverfahrenstechnik, Bergstrasse 120, D-01062 Dresden (Germany); Zehnsdorf, A. [UFZ-Umweltforschungszentrum Leipzig-Halle GmbH, Umwelt- und Biotechnologisches Zentrum, Permoserstrasse 15, D-04318 Leipzig (Germany); Hoffmann, P.; Seidel, H. [UFZ-Umweltforschungszentrum Leipzig-Halle GmbH, Department Bioremediation, Permoserstrasse 15, D-04318 Leipzig (Germany)

    2006-08-15

    A remediation process for heavy metal polluted sediment has previously been developed, in which the heavy metals are removed from the sediment by solid-bed bioleaching using sulfuric acid as a leaching agent arising from added elemental sulfur (S{sup 0}). This process has been engineered with Weisse Elster River sediment (dredged near Leipzig, Germany), as an example. Here, six heavy metal polluted sediments originating from various bodies of water in Germany were subjected to bioleaching to evaluate the applicability of the developed process on sediment of different nature: each sediment was mixed with 2 % S{sup 0}, suspended in water and then leached under identical conditions. The buffer characteristics of each sediment were mainly governed by its carbonate and Ca content, i.e., by its geological background, the redox potential and oxidation state depended on its pre-treatment (e.g., on land disposal), while the pH value was influenced by both. The added S{sup 0} was quickly oxidized by the indigenous microbes even in slightly alkaline sediment. The microbially generated H{sub 2}SO{sub 4} accumulated in the aqueous phase and was in part precipitated as gypsum. Significant acidification and heavy metal solubilization only occurred with sediment poor in buffer substances. With the exception of one sediment, the behavior in bioleaching correlated well with the behavior in titration with H{sub 2}SO{sub 4}. Since the content in carbonate seemed to be the most important factor deciding on the leachability of a sediment, oxic Weisse Elster River sediment was mixed with 2 % S{sup 0} and 0 to 100 g/kg of ground limestone to simulate various buffer capacities, suspended in water and then leached. The lime did not inhibit microbial S{sup 0} oxidation but generated a delay in acidification due to neutralization of formed H{sub 2}SO{sub 4}, where the pH only started to decrease when the lime was completely consumed. The more lime the sediment contained, the longer this lag

  15. Keeping agricultural soil out of rivers: evidence of sediment and nutrient accumulation within field wetlands in the UK.

    Science.gov (United States)

    Ockenden, Mary C; Deasy, Clare; Quinton, John N; Surridge, Ben; Stoate, Chris

    2014-03-15

    Intensification of agriculture has resulted in increased soil degradation and erosion, with associated pollution of surface waters. Small field wetlands, constructed along runoff pathways, offer one option for slowing down and storing runoff in order to allow more time for sedimentation and for nutrients to be taken up by plants or micro-organisms. This paper describes research to provide quantitative evidence for the effectiveness of small field wetlands in the UK landscape. Ten wetlands were built on four farms in Cumbria and Leicestershire, UK. Annual surveys of sediment and nutrient accumulation in 2010, 2011 and 2012 indicated that most sediment was trapped at a sandy site (70 tonnes over 3 years), compared to a silty site (40 tonnes over 3 years) and a clay site (2 tonnes over 3 years). The timing of rainfall was more important than total annual rainfall for sediment accumulation, with most sediment transported in a few intense rainfall events, especially when these coincided with bare soil or poor crop cover. Nutrient concentration within sediments was inversely related to median particle size, but the total mass of nutrients trapped was dependent on the total mass of sediment trapped. Ratios of nutrient elements in the wetland sediments were consistent between sites, despite different catchment characteristics across the individual wetlands. The nutrient value of sediment collected from the wetlands was similar to that of soil in the surrounding fields; dredged sediment was considered to have value as soil replacement but not as fertiliser. Overall, small field wetlands can make a valuable contribution to keeping soil out of rivers. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Argonne National Laboratory Site Environmental report for calendar year 2009.

    Energy Technology Data Exchange (ETDEWEB)

    Golchert, N. W.; Davis, T. M.; Moos, L. P.

    2010-08-04

    This report discusses the status and the accomplishments of the environmental protection program at Argonne National Laboratory for calendar year 2009. The status of Argonne environmental protection activities with respect to compliance with the various laws and regulations is discussed, along with the progress of environmental corrective actions and restoration projects. To evaluate the effects of Argonne operations on the environment, samples of environmental media collected on the site, at the site boundary, and off the Argonne site were analyzed and compared with applicable guidelines and standards. A variety of radionuclides were measured in air, surface water, on-site groundwater, and bottom sediment samples. In addition, chemical constituents in surface water, groundwater, and Argonne effluent water were analyzed. External penetrating radiation doses were measured, and the potential for radiation exposure to off-site population groups was estimated. Results are interpreted in terms of the origin of the radioactive and chemical substances (i.e., natural, Argonne, and other) and are compared with applicable environmental quality standards. A U.S. Department of Energy (DOE) dose calculation methodology, based on International Commission on Radiological Protection recommendations and the U.S. Environmental Protection Agency's (EPA) CAP-88 Version 3 (Clean Air Act Assessment Package-1988) computer code, was used in preparing this report.

  17. Argonne National Laboratory Site Environmental Report for Calendar Year 2013

    Energy Technology Data Exchange (ETDEWEB)

    Davis, T. M. [Argonne National Lab. (ANL), Argonne, IL (United States); Gomez, J. L. [Argonne National Lab. (ANL), Argonne, IL (United States); Moos, L. P. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-09-02

    This report discusses the status and the accomplishments of the environmental protection program at Argonne National Laboratory for calendar year 2013. The status of Argonne environmental protection activities with respect to compliance with the various laws and regulations is discussed, along with environmental management, sustainability efforts, environmental corrective actions, and habitat restoration. To evaluate the effects of Argonne operations on the environment, samples of environmental media collected on the site, at the site boundary, and off the Argonne site were analyzed and compared with applicable guidelines and standards. A variety of radionuclides were measured in air, surface water, on-site groundwater, and bottom sediment samples. In addition, chemical constituents in surface water, groundwater, and Argonne effluent water were analyzed. External penetrating radiation doses were measured, and the potential for radiation exposure to off-site population groups was estimated. Results are interpreted in terms of the origin of the radioactive and chemical substances (i.e., natural, Argonne, and other) and are compared with applicable standards intended to protect human health and the environment. A U.S. Department of Energy (DOE) dose calculation methodology, based on International Commission on Radiological Protection (ICRP) recommendations and the U.S. Environmental Protection Agency’s (EPA) CAP-88 Version 3 computer code, was used in preparing this report.

  18. Argonne National Laboratory site environmental report for calendar year 2007.

    Energy Technology Data Exchange (ETDEWEB)

    Golchert, N. W.; Davis, T. M.; Moos, L. P.; ESH/QA Oversight

    2008-09-09

    This report discusses the status and the accomplishments of the environmental protection program at Argonne National Laboratory for calendar year 2007. The status of Argonne environmental protection activities with respect to compliance with the various laws and regulations is discussed, along with the progress of environmental corrective actions and restoration projects. To evaluate the effects of Argonne operations on the environment, samples of environmental media collected on the site, at the site boundary, and off the Argonne site were analyzed and compared with applicable guidelines and standards. A variety of radionuclides were measured in air, surface water, on-site groundwater, and bottom sediment samples. In addition, chemical constituents in surface water, groundwater, and Argonne effluent water were analyzed. External penetrating radiation doses were measured, and the potential for radiation exposure to off-site population groups was estimated. Results are interpreted in terms of the origin of the radioactive and chemical substances (i.e., natural, fallout, Argonne, and other) and are compared with applicable environmental quality standards. A U.S. Department of Energy dose calculation methodology, based on International Commission on Radiological Protection recommendations and the U.S. Environmental Protection Agency's CAP-88 Version 3 (Clean Air Act Assessment Package-1988) computer code, was used in preparing this report.

  19. Argonne National Laboratory site enviromental report for calendar year 2008.

    Energy Technology Data Exchange (ETDEWEB)

    Golchert, N. W.; Davis, T. M.; Moos, L. P.

    2009-09-02

    This report discusses the status and the accomplishments of the environmental protection program at Argonne National Laboratory for calendar year 2008. The status of Argonne environmental protection activities with respect to compliance with the various laws and regulations is discussed, along with the progress of environmental corrective actions and restoration projects. To evaluate the effects of Argonne operations on the environment, samples of environmental media collected on the site, at the site boundary, and off the Argonne site were analyzed and compared with applicable guidelines and standards. A variety of radionuclides were measured in air, surface water, on-site groundwater, and bottom sediment samples. In addition, chemical constituents in surface water, groundwater, and Argonne effluent water were analyzed. External penetrating radiation doses were measured, and the potential for radiation exposure to off-site population groups was estimated. Results are interpreted in terms of the origin of the radioactive and chemical substances (i.e., natural, fallout, Argonne, and other) and are compared with applicable environmental quality standards. A U.S. Department of Energy dose calculation methodology, based on International Commission on Radiological Protection recommendations and the U.S. Environmental Protection Agency's CAP-88 Version 3 (Clean Air Act Assessment Package-1988) computer code, was used in preparing this report.

  20. Argonne National Laboratory site environmental report for calendar year 2004.

    Energy Technology Data Exchange (ETDEWEB)

    Golchert, N. W.; Kolzow, R. G.

    2005-09-02

    This report discusses the accomplishments of the environmental protection program at Argonne National Laboratory (ANL) for calendar year 2004. The status of ANL environmental protection activities with respect to compliance with the various laws and regulations is discussed, along with the progress of environmental corrective actions and restoration projects. To evaluate the effects of ANL operations on the environment, samples of environmental media collected on the site, at the site boundary, and off the ANL site were analyzed and compared with applicable guidelines and standards. A variety of radionuclides were measured in air, surface water, on-site groundwater, and bottom sediment samples. In addition, chemical constituents in surface water, groundwater, and ANL effluent water were analyzed. External penetrating radiation doses were measured, and the potential for radiation exposure to off-site population groups was estimated. Results are interpreted in terms of the origin of the radioactive and chemical substances (i.e., natural, fallout, ANL, and other) and are compared with applicable environmental quality standards. A U.S. Department of Energy dose calculation methodology, based on International Commission on Radiological Protection recommendations and the U.S. Environmental Protection Agency's CAP-88 (Clean Air Act Assessment Package-1988) computer code, was used in preparing this report.

  1. Argonne National Laboratory site environmental report for calendar year 2006.

    Energy Technology Data Exchange (ETDEWEB)

    Golchert, N. W.; ESH/QA Oversight

    2007-09-13

    This report discusses the status and the accomplishments of the environmental protection program at Argonne National Laboratory for calendar year 2006. The status of Argonne environmental protection activities with respect to compliance with the various laws and regulations is discussed, along with the progress of environmental corrective actions and restoration projects. To evaluate the effects of Argonne operations on the environment, samples of environmental media collected on the site, at the site boundary, and off the Argonne site were analyzed and compared with applicable guidelines and standards. A variety of radionuclides were measured in air, surface water, on-site groundwater, and bottom sediment samples. In addition, chemical constituents in surface water, groundwater, and Argonne effluent water were analyzed. External penetrating radiation doses were measured, and the potential for radiation exposure to off-site population groups was estimated. Results are interpreted in terms of the origin of the radioactive and chemical substances (i.e., natural, fallout, Argonne, and other) and are compared with applicable environmental quality standards. A U.S. Department of Energy dose calculation methodology, based on International Commission on Radiological Protection recommendations and the U.S. Environmental Protection Agency's CAP-88 Version 3 (Clean Air Act Assessment Package-1988) computer code, was used in preparing this report.

  2. Spatial and temporal trends in PCBs in sediment along the lower Rhone River, France

    Energy Technology Data Exchange (ETDEWEB)

    Desmet, Marc, E-mail: marc.desmet@univ-tours.fr [EA 6293 GeHCO Universite Francois-Rabelais de Tours, Parc de Grandmont, 37200 Tours (France); Mourier, Brice, E-mail: brice.mourier@entpe.fr [Universite Lyon 1, UMR 5023 Ecologie des Hydrosystemes Naturels et Anthropises, ENTPE, CNRS, 3, Rue Maurice Audin, 69518 Vaulx-en-Velin (France); Mahler, Barbara J., E-mail: bjmahler@usgs.gov [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Van Metre, Peter C., E-mail: pcvanmet@usgs.gov [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Roux, Gwenaeelle, E-mail: gwenaelle.roux@entpe.fr [Universite Lyon 1, UMR 5023 Ecologie des Hydrosystemes Naturels et Anthropises, ENTPE, CNRS, 3, Rue Maurice Audin, 69518 Vaulx-en-Velin (France); Persat, Henri, E-mail: persat@biomserv.univ-lyon1.fr [Universite de Lyon, UMR 5023 Ecologie des Hydrosystemes Naturels et Anthropises, Universite Lyon 1, ENTPE, CNRS, 5 rue Raphaeel Dubois, 69221 Villeurbanne (France); Lefevre, Irene, E-mail: Irene.Lefevre@lsce.ipsl.fr [UMR 8212, LSCE, Bat. 12, avenue de la Terrasse, F-91198 Gif-sur-Yvette Cedex (France); Peretti, Annie, E-mail: royannie@gmail.com [Irstea, UR MALY, 3 bis Quai Chauveau, CP220, F-69336 Lyon (France); and others

    2012-09-01

    Despite increasingly strict control of polychlorinated biphenyl (PCB) releases in France since the mid-1970s, PCB contamination of fish recently has emerged as a major concern in the lower Rhone River basin. We measured PCB concentrations in Rhone sediment to evaluate the effects of PCB releases from major urban and industrial areas, sediment redistribution by large floods, and regulatory controls on PCB trends from 1970 to present. Profiles of PCBs (the sum of seven indicator PCB congeners) were reconstructed from sediment cores collected from an off-river rural reference site and from three depositional areas along the Rhone upstream and downstream from the city of Lyon, France. Core chronology was determined from radionuclide profiles and flood deposits. PCB concentrations increased progressively in the downstream direction, and reached a maximum concentration in 1991 of 281 {mu}g/kg at the most downstream site. At the rural reference site and at the upstream Rhone site, PCB concentrations peaked in the 1970s (maximum concentration of 13 and 78 {mu}g/kg, respectively) and have decreased exponentially since then. PCB concentrations in the middle and downstream cores were elevated into the early 1990s, decreased very rapidly until 2000, and since then have remained relatively stable. Congener profiles for three time windows (1965-80, 1986-93, and 2000-08) were similar in the three sediment cores from the Rhone and different from those at the rural reference site. The results indicate that permitted discharges from a hazardous-waste treatment facility upstream from Lyon might have contributed to high concentrations into the 1980-90s, but that industrial discharges from the greater Lyon area and tributaries to the Rhone near Lyon have had a greater contribution since the 1990s. There is little indication that PCB concentration in sediments downstream from Lyon will decrease over at least the short term. -- Highlights: Black-Right-Pointing-Pointer We reconstructed

  3. Fluvial sediment in the environment: a national challenge

    Science.gov (United States)

    Larsen, Matthew C.; Gellis, Allen C.; Glysson, G. Douglas; Gray, John R.; Horowitz, Arthur J.

    2010-01-01

    Sediment and sediment-associated constituents can contribute substantially to water-quality impairment. In the past, sediment was viewed mainly as an engineering problem that affected reservoir storage capacity, shipping channel maintenance, and bridge scour, as well as the loss of agricultural soil. Sediment is now recognized as a major cause of aquatic system degradation in many rivers and streams as a result of light attenuation, loss of spawning substrate due to fine-grained sediment infilling, reduction in primary productivity, decreases in biotic diversity, and effects from sediment-associated chemical constituents. Recent advances in sediment measurement, assessment, source-identification, and analytical protocols provide new capabilities to quantify sediment and solid-phase chemical fluxes in aquatic systems. Developing, maintaining, and augmenting current sediment- and water-quality-monitoring networks is essential for determining the health of U.S. waterways and for evaluating the effectiveness of management actions in reducing sediment-related problems. The application of new scientific capabilities that address the adverse effects of sediment and sediment- associated constituents represents a major step in managing the Nation’s water quality. A robust Federal, national-scale eff rt, in collaboration with vested stakeholders, is needed to address these sediment-related water-quality issues across the United States.

  4. Thermal conductivity measurements of Pacific illite sediment

    International Nuclear Information System (INIS)

    Hickox, C.E.; McVey, D.F.; Miller, J.B.; Olson, L.O.; Silva, A.J.

    1986-01-01

    Results are reported for effective thermal conductivity measurements performed in situ and in core samples of illite marine sediment. The measurements were obtained during a recent oceanographic expedition to a study site in the north central region of the Pacific Ocean. This study was undertaken in support of the US Subseabed Disposal Project, the purpose of which is to investigate the scientific feasibility of using the fine grained sediments of the sea floor as a repository for high level nuclear waste. In situ measurements were made and 1.5-meter long hydrostatic piston cores were taken, under remote control, from a platform that was lowered to the sea floor, 5844 m below sea level. The in situ measurement of thermal conductivity was made at a nominal depth of 80 cm below the sediment surface using a specially developed, line source, needle probe. Thermal conductivity measurements in three piston cores and one box core (obtained several kilometers from the study site) were made on shipboard using a miniature needle probe. The in situ thermal conductivity was approximately 0.91 W/m.K. Values determined from the cores were within the range 0.81 to 0.89 W/m.K

  5. Ecotoxicological risk assessment linked to infilling quarries with treated dredged seaport sediments

    Energy Technology Data Exchange (ETDEWEB)

    Perrodin, Yves, E-mail: perrodin@entpe.fr [Universite de Lyon, ENTPE, CNRS, UMR 5023 LEHNA, 2 rue Maurice Audin, 69518 Vaulx-en-Velin (France); Donguy, Gilles [Universite de Lyon, ENTPE, CNRS, UMR 5023 LEHNA, 2 rue Maurice Audin, 69518 Vaulx-en-Velin (France); Bazin, Christine [INSAVALOR, 20 avenue Albert Einstein, 69621 Villeurbanne Cedex (France); Volatier, Laurence; Durrieu, Claude [Universite de Lyon, ENTPE, CNRS, UMR 5023 LEHNA, 2 rue Maurice Audin, 69518 Vaulx-en-Velin (France); Bony, Sylvie; Devaux, Alain [Universite de Lyon, ENTPE, CNRS, UMR 5023 LEHNA, 2 rue Maurice Audin, 69518 Vaulx-en-Velin (France); INRA, USC IGH, UMR LEHNA, 2, rue Maurice Audin, 69518 Vaulx-en-Velin (France); Abdelghafour, Mohammed; Moretto, Robert [INSAVALOR, 20 avenue Albert Einstein, 69621 Villeurbanne Cedex (France)

    2012-08-01

    The dredged sediments of polluted seaports now raise complex management problems since it is no longer possible to discharge them into the sea. This results in the need to manage them on land, raising other types of technical, economic and environmental problems. Regarding the technical and economic dimensions, traditional waste treatment methods have proved to be poorly adapted, due to very high costs and low absorbable volumes. In this context, filling quarries in coastal areas with treated sediments could represent an interesting alternative for these materials. Nevertheless, for the environmental dimension, it is necessary to demonstrate that this possibility is harmless to inland ecosystems. Consequently, a specific ecotoxicological risk assessment methodology has been formulated and tested on three sediments taken from seaboards of France, in view to providing an operational and usable tool for the prior validation of any operation to fill quarries with treated seaport sediments. This method incorporates the formulation of a global conceptual model of the scenario studied and the definition of protocols for each of its steps: the characterisation of exposures (based on a simulation of sediment deposit), the characterisation of effects (via the study of sediments ecotoxicity), and the final ecotoxicological risk assessment performed as a calculation of a risk quotient. It includes the implementation in parallel of two types of complementary approach: the 'substances' approach derived from the European methodology for assessing new substances placed on the market, and the 'matrix' approach which is similar to methods developed in France to assess ecological risks in other domains (waste management, polluted site management, Horizontal-Ellipsis ). The application of this dual approach to the three sediments tested led to conclude with reliability that the project to deposit sediments '1' and '2' presented a low risk for

  6. Ecotoxicological risk assessment linked to infilling quarries with treated dredged seaport sediments

    International Nuclear Information System (INIS)

    Perrodin, Yves; Donguy, Gilles; Bazin, Christine; Volatier, Laurence; Durrieu, Claude; Bony, Sylvie; Devaux, Alain; Abdelghafour, Mohammed; Moretto, Robert

    2012-01-01

    The dredged sediments of polluted seaports now raise complex management problems since it is no longer possible to discharge them into the sea. This results in the need to manage them on land, raising other types of technical, economic and environmental problems. Regarding the technical and economic dimensions, traditional waste treatment methods have proved to be poorly adapted, due to very high costs and low absorbable volumes. In this context, filling quarries in coastal areas with treated sediments could represent an interesting alternative for these materials. Nevertheless, for the environmental dimension, it is necessary to demonstrate that this possibility is harmless to inland ecosystems. Consequently, a specific ecotoxicological risk assessment methodology has been formulated and tested on three sediments taken from seaboards of France, in view to providing an operational and usable tool for the prior validation of any operation to fill quarries with treated seaport sediments. This method incorporates the formulation of a global conceptual model of the scenario studied and the definition of protocols for each of its steps: the characterisation of exposures (based on a simulation of sediment deposit), the characterisation of effects (via the study of sediments ecotoxicity), and the final ecotoxicological risk assessment performed as a calculation of a risk quotient. It includes the implementation in parallel of two types of complementary approach: the “substances” approach derived from the European methodology for assessing new substances placed on the market, and the “matrix” approach which is similar to methods developed in France to assess ecological risks in other domains (waste management, polluted site management, …). The application of this dual approach to the three sediments tested led to conclude with reliability that the project to deposit sediments “1” and “2” presented a low risk for the peripheral aquatic ecosystems while

  7. Sediment Chemistry and Toxicity in Barnegat Bay, New Jersey: Pre- and Post- Hurricane Sandy, 2012-2013.

    Science.gov (United States)

    Romanok, Kristin M.; Szabo, Zoltan; Reilly, Timothy J.; Defne, Zafer; Ganju, Neil K.

    2016-01-01

    Hurricane Sandy made landfall in Barnegat Bay, October, 29, 2012, damaging shorelines and infrastructure. Estuarine sediment chemistry and toxicity were investigated before and after to evaluate potential environmental health impacts and to establish post-event baseline sediment-quality conditions. Trace element concentrations increased throughout Barnegat Bay up to two orders of magnitude, especially north of Barnegat Inlet, consistent with northward redistribution of silt. Loss of organic compounds, clay, and organic carbon is consistent with sediment winnowing and transport through the inlets and sediment transport modeling results. The number of sites exceeding sediment quality guidance levels for trace elements tripled post-Sandy. Sediment toxicity post-Sandy was mostly unaffected relative to pre-Sandy conditions, but at the site with the greatest relative increase for trace elements, survival rate of the test amphipod decreased (indicating degradation). This study would not have been possible without comprehensive baseline data enabling the evaluation of storm-derived changes in sediment quality.

  8. [Distribution Characteristics and Pollution Status Evaluation of Sediments Nutrients in a Drinking Water Reservoir].

    Science.gov (United States)

    Huang, Ting-lin; Liu, Fei; Shi, Jian-chao

    2016-01-15

    The main purpose of this paper is to illustrate the influence of nutrients distribution in sediments on the eutrophication of drinking water reservoir. The sediments of three representative locations were field-sampled and analyzed in laboratory in March 2015. The distribution characteristics of TOC, TN and TP were measured, and the pollution status of sediments was evaluated by the comprehensive pollution index and the manual for sediment quality assessment. The content of TOC in sediments decreased with depth, and there was an increasing trend of the nitrogen content. The TP was enriched in surface sediment, implying the nutrients load in Zhoucun Reservoir was aggravating as the result of human activities. Regression analysis indicated that the content of TOC in sediments was positively correlated with contents of TN and TP in sediments. The TOC/TN values reflected that the vascular land plants, which contain cellulose, were the main source of organic matter in sediments. The comprehensive pollution index analysis result showed that the surface sediments in all three sampling sites were heavily polluted. The contents of TN and TP of surface sediments in three sampling sites were 3273-4870 mg x kg(-1) and 653-2969 mg x kg(-1), and the content of TOC was 45.65-83.00 mg x g(-1). According to the manual for sediment quality assessment, the TN, TP and TOC contents in sediments exceed the standard values for the lowest level of ecotoxicity, so there is a risk of eutrophication in Zhoucun Reservoir.

  9. Thallium dispersal and contamination in surface sediments from South China and its source identification.

    Science.gov (United States)

    Liu, Juan; Wang, Jin; Chen, Yongheng; Shen, Chuan-Chou; Jiang, Xiuyang; Xie, Xiaofan; Chen, Diyun; Lippold, Holger; Wang, Chunlin

    2016-06-01

    Thallium (Tl) is a non-essential element in humans and it is considered to be highly toxic. In this study, the contents, sources, and dispersal of Tl were investigated in surface sediments from a riverine system (the western Pearl River Basin, China), whose catchment has been contaminated by mining and roasting of Tl-bearing pyrite ores. The isotopic composition of Pb and total contents of Tl and other relevant metals (Pb, Zn, Cd, Co, and Ni) were measured in the pyrite ores, mining and roasting wastes, and the river sediments. Widespread contamination of Tl was observed in the sediments across the river, with the highest concentration of Tl (17.3 mg/kg) measured 4 km downstream from the pyrite industrial site. Application of a modified Institute for Reference Materials and Measurement (IRMM) sequential extraction scheme in representative sediments unveiled that 60-90% of Tl and Pb were present in the residual fraction of the sediments. The sediments contained generally lower (206)Pb/(207)Pb and higher (208)Pb/(206)Pb ratios compared with the natural Pb isotope signature (1.2008 and 2.0766 for (206)Pb/(207)Pb and (208)Pb/(206)Pb, respectively). These results suggested that a significant fraction of non-indigenous Pb could be attributed to the mining and roasting activities of pyrite ores, with low (206)Pb/(207)Pb (1.1539) and high (208)Pb/(206)Pb (2.1263). Results also showed that approximately 6-88% of Tl contamination in the sediments originated from the pyrite mining and roasting activities. This study highlights that Pb isotopic compositions could be used for quantitatively fingerprinting the sources of Tl contamination in sediments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Sediment sequence and site formation processes at the Arbreda Cave, NE Iberian Peninsula, and implications on human occupation and climate change during the Last Glacial

    Directory of Open Access Journals (Sweden)

    M. Kehl

    2014-09-01

    Full Text Available The Arbreda Cave provides a detailed archaeological record of the Middle to Upper Palaeolithic and is a key site for studying human occupation and cultural transitions in NE Iberia. Recently, studies of lake archives and archaeological sites presented new evidence on climate changes in NE Iberia correlating with Heinrich events. It, therefore, needs to be determined whether climate signals can be identified in the cave sequence of Arbreda, and if so, whether these signals can be correlated with stratigraphic indicators suggesting the continuity or discontinuity of human occupation. We conducted a high-resolution sedimentological and geochemical study, including micromorphological investigations, to shed light on stratigraphy, processes of sediment accumulation and post-depositional alteration in the cave. Seven major sediment units were distinguished which partly correlate with archaeological levels. The lower part of the sequence including Mousterian levels J and K consists of fluvial deposits truncated by a sharp erosional disconformity between Mousterian levels J and I. Strong enrichment with phosphorus and strontium reflect zoogenic inputs. The transition from Mousterian to Archaic Aurignacian in levels I and H, respectively, is reflected by more gradual changes in colour, grain size and geochemical composition. However, a peak in potentially wind-blown particles (40–125 μm in diameter reflects higher aeolian input, and banded microstructure suggests reworking of sediments at the interface. Both properties correlate with low density of finds suggesting low intensity of human occupation related to a dry spell. More arid conditions than during the Holocene are indicated for the Gravettian to Solutrean levels. These findings are in agreement with previous palaeoclimatic interpretations as based on palaeontological proxies. The detailed multi-proxy analyses of the sequence adds to our understanding on sediment accumulation and alteration in

  11. Interactive 4D Visualization of Sediment Transport Models

    Science.gov (United States)

    Butkiewicz, T.; Englert, C. M.

    2013-12-01

    Coastal sediment transport models simulate the effects that waves, currents, and tides have on near-shore bathymetry and features such as beaches and barrier islands. Understanding these dynamic processes is integral to the study of coastline stability, beach erosion, and environmental contamination. Furthermore, analyzing the results of these simulations is a critical task in the design, placement, and engineering of coastal structures such as seawalls, jetties, support pilings for wind turbines, etc. Despite the importance of these models, there is a lack of available visualization software that allows users to explore and perform analysis on these datasets in an intuitive and effective manner. Existing visualization interfaces for these datasets often present only one variable at a time, using two dimensional plan or cross-sectional views. These visual restrictions limit the ability to observe the contents in the proper overall context, both in spatial and multi-dimensional terms. To improve upon these limitations, we use 3D rendering and particle system based illustration techniques to show water column/flow data across all depths simultaneously. We can also encode multiple variables across different perceptual channels (color, texture, motion, etc.) to enrich surfaces with multi-dimensional information. Interactive tools are provided, which can be used to explore the dataset and find regions-of-interest for further investigation. Our visualization package provides an intuitive 4D (3D, time-varying) visualization of sediment transport model output. In addition, we are also integrating real world observations with the simulated data to support analysis of the impact from major sediment transport events. In particular, we have been focusing on the effects of Superstorm Sandy on the Redbird Artificial Reef Site, offshore of Delaware Bay. Based on our pre- and post-storm high-resolution sonar surveys, there has significant scour and bedform migration around the

  12. Fixation of Cs to marine sediments estimated by a stochastic modelling approach.

    Science.gov (United States)

    Børretzen, Peer; Salbu, Brit

    2002-01-01

    Dumping of nuclear waste in the Kara Sea represents a potential source of radioactive contamination to the Arctic Seas in the future. The mobility of 137Cs ions leached from the waste will depend on the interactions with sediment particles. Whether sediments will act as a continuous permanent sink for released 137Cs, or contaminated sediments will serve as a diffuse source of 137Cs in the future, depends on the interaction kinetics and binding mechanisms involved. The main purpose of this paper is to study the performance of different stochastic models using kinetic information to estimate the time needed for Cs ions to become irreversibly fixed within the sediments. The kinetic information was obtained from 134Cs tracer sorption and desorption (sequential extractions) experiments, conducted over time, using sediments from the Stepovogo Fjord waste dumping site, on the east coast of Novaya Zemlya. Results show that 134Cs ions interact rapidly with the surfaces of the Stepovogo sediment, with an estimated distribution coefficient Kd(eq) of 300 ml/g (or 13m2/g), and the 134Cs ions are increasingly irreversibly fixed to the sediment over time. For the first time, stochastic theory has been utilised for sediment-seawater systems to estimate the mean residence times (MRTs) of Cs ions in operationally defined sediment phases described by compartment models. In the present work, two different stochastic models (i) a Markov process model (MP) being analogous to deterministic compartment models, and (ii) a semi-Markov process model (SMP) which should be physically more relevant for inhomogeneous systems, have been compared. As similar results were obtained using the two models, the less complicated MP model was utilised to predict the time needed for an average Cs ion to become irreversibly fixed in the Stepovogo sediments. According the model, approximately 1100 days of contact time between Cs ions and sediments is needed before 50% of the 134Cs ion becomes fixed in the

  13. Shallow water table effects on water, sediment, and pesticide transport in vegetative filter strips – Part 2: model coupling, application, factor importance, and uncertainty

    Directory of Open Access Journals (Sweden)

    C. Lauvernet

    2018-01-01

    Full Text Available Vegetative filter strips are often used for protecting surface waters from pollution transferred by surface runoff in agricultural watersheds. In Europe, they are often prescribed along the stream banks, where a seasonal shallow water table (WT could decrease the buffer zone efficiency. In spite of this potentially important effect, there are no systematic experimental or theoretical studies on the effect of this soil boundary condition on the VFS efficiency. In the companion paper (Muñoz-Carpena et al., 2018, we developed a physically based numerical algorithm (SWINGO that allows the representation of soil infiltration with a shallow water table. Here we present the dynamic coupling of SWINGO with VFSMOD, an overland flow and transport mathematical model to study the WT influence on VFS efficiency in terms of reductions of overland flow, sediment, and pesticide transport. This new version of VFSMOD was applied to two contrasted benchmark field studies in France (sandy-loam soil in a Mediterranean semicontinental climate, and silty clay in a temperate oceanic climate, where limited testing of the model with field data on one of the sites showed promising results. The application showed that for the conditions of the studies, VFS efficiency decreases markedly when the water table is 0 to 1.5 m from the surface. In order to evaluate the relative importance of WT among other input factors controlling VFS efficiency, global sensitivity and uncertainty analysis (GSA was applied on the benchmark studies. The most important factors found for VFS overland flow reduction were saturated hydraulic conductivity and WT depth, added to sediment characteristics and VFS dimensions for sediment and pesticide reductions. The relative importance of WT varied as a function of soil type (most important at the silty-clay soil and hydraulic loading (rainfall + incoming runoff at each site. The presence of WT introduced more complex responses dominated by strong

  14. Immunotoxicity in plaice exposed to marine sediments in Baie des Anglais on the St. Lawrence Estuary

    Energy Technology Data Exchange (ETDEWEB)

    Lacroix, A. [Univ. of Quebec, Montreal, Quebec (Canada); Nagler, J.; Lee, K.; Lebeuf, M.; Cyr, D. [Fisheries and Oceans Canada, Mont-Joli, Quebec (Canada); Fournier, M. [Univ. of Quebec, Montreal, Quebec (Canada)]|[Fisheries and Oceans Canada, Mont-Joli, Quebec (Canada)

    1995-12-31

    The sediments of Baie des Anglais on the St. Lawrence Estuary have a history of environmental contamination. The purpose of the present study was to determine whether or not the immune system of American Plaice (Hippoglossoides Platessoides) could be affected following in-situ exposure at three different sites in and near Baie des Anglais. These sites vary with their proximity to local industry, Sites 1 and 2 (within the bay) being the closest and Site 3 (outside the bay) the furthest away. Fishes placed in cages at each site for three weeks, displayed head kidney cell immune responses (i.e., phagocytosis) modifications indicating that Site 1 was most immunotoxic and site 3 the least. Sediment chemical analysis show a gradient in contaminant concentrations with the highest levels recorded at Site 1, about 10-fold less at Site 2 and 100-fold less at Site 3. Organics predominated (PAHs, PCBs, PCDFs) with heavy metal concentrations low and representative of background levels for the St. Lawrence Estuary. The results obtained indicate that contaminants present in the sediments are bioavailable to fish and significantly affect their immune system.

  15. Immobilization and Natural Attenuation of Arsenic in Surface and Subsurface Sediments

    Science.gov (United States)

    O'Day, P. A.; Illera, V.; Choi, S.; Vlassopoulos, D.

    2008-12-01

    Understanding of molecular-scale biogeochemical processes that control the mobilization and distribution of As and other oxyanions can be used to develop remediation strategies that take advantage of natural geochemical and hydrologic gradients. Arsenic and other toxic oxyanions can be mobilized at low bulk sediment concentrations (ppm range) and thus, treatment technologies are challenged by low contaminant concentrations, widespread sources, variable pH and Eh conditions, and inaccessibility of subsurface environments. In situ chemical amendments to soils and sediments can be used to decrease the mobility and bioaccessibility of As and oxyanions through sorption to, or precipitation with, stabilizing phases. At a site near San Francisco Bay (CA, USA), treatment of As-contaminated soils with sulfate-cement amendments has effectively immobilized As. Laboratory experiments with field soils and spectroscopic characterizations showed that in high pH cement-type treatments, As is precipitated in ettringite-type phases (Ca-Al sulfates), whereas in low pH ferrous sulfate treatments, As is associated with an iron-arsenate phase (angellelite). The presence of As-associated ettringite-type phases in field sediments amended more than a decade ago indicates long-term stability of these neophases, as long as environmental conditions are relatively constant. At sites of subsurface contamination, monitored natural attenuation (MNA) as a remediation approach for As is gaining interest and acceptance. Successful implementation of MNA requires a mechanistic understanding of As sequestration processes and of the subsurface conditions that may enhance or reduce long-term effectiveness. At a former military site (MA, USA), naturally occurring As was mobilized from sediments as a result of reducing conditions from addition of organic carbon as a biodegradation treatment of chlorinated solvents. Elevated As concentrations were not detected further than about 30 m downgradient of the

  16. Ripening of clayey dredged sediments during temporary upland disposal, A Bioremediation technique.

    NARCIS (Netherlands)

    Vermeulen, J.; Grotenhuis, J.T.C.; Joziasse, J.; Rulkens, W.H.

    2003-01-01

    Background and Goal. In the Netherlands about 40 million m3 of sediment has to be dredged annually for both maintenance and environmental reasons. Temporary upland disposal is the most widely adopted alternative for dredged sediments worldwide. For good management of temporary disposal sites,

  17. Soil and Sediment remediation, mechanisms, technologies and applications

    NARCIS (Netherlands)

    Lens, P.N.L.; Grotenhuis, J.T.C.; Malina, G.; Tabak, H.H.

    2005-01-01

    Technologies for the treatment of soils and sediments in-situ (landfarming, bioscreens, bioventing, nutrient injection, phytoremediation) and ex-situ (landfarming, bio-heap treatment, soil suspension reactor) will be discussed. The microbiological, process technological and socio-economical aspects

  18. Polyphosphates as a source of enhanced P fluxes in marine sediments overlain by anoxic waters: Evidence from 31P NMR

    Directory of Open Access Journals (Sweden)

    Ingall Ellery

    2005-06-01

    Full Text Available Sedimentary phosphorus (P composition was investigated in Effingham Inlet, a fjord located on the west coast of Vancouver Island in Barkley Sound. Solid-state 31P nuclear magnetic resonance (NMR spectroscopy was applied to demineralized sediment samples from sites overlain by oxic and anoxic bottom waters. The two sites were similar in terms of key diagenetic parameters, including the mass accumulation rate, integrated sulfate reduction rate, and bulk sediment organic carbon content. In contrast, P benthic fluxes were much higher at the anoxic site. 31P NMR results show that P esters and phosphonates are the major organic P species present at the surface and at depth in sediments at both sites. Polyphosphates were only found in the surface sediment of the site overlain by oxic waters. The varying stability of polyphosphates in microorganisms under different redox conditions may, in part, explain their distribution as well as differences in P flux between the two sites.

  19. Polycyclic aromatic hydrocarbons in sediments and mussels of Corral Bay, south central Chile.

    Science.gov (United States)

    Palma-Fleming, Hernan; P, Adalberto J Asencio; Gutierrez, Elena

    2004-03-01

    PAHs were measured in sediments and mussels (Mytilus chilensis) from Carboneros and Puerto Claro, located in Corral Bay, Valdivia. According to the ratio of phenanthrene/anthracene and fluoranthene/pyrene concentrations, these sites are medium polluted with PAHs originating mainly from pyrolytic sources. Fluoranthene was the major component measured in mussels (3.1-390 ng g(-1) dry weight) and sediments (6.9-74.1 ng g(-1) dry weight). In general, mussels were mainly exposed to the dissolved fraction of the lower molecular weight PAHs (tri- and tetra-aromatics) while the higher molecular ring systems (penta- and hexa-aromatics) were more bioavailable to sediments. Mussel PAHs content was relatively constant, with the exception of the 1999 summer season (March), when higher concentration values were found in both sites; however, PAHs residues in sediments showed a temporal variation.

  20. Siting guidelines for utility application of wind turbines. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pennell, W.T.

    1983-01-01

    Utility-oriented guidelines are described for identifying viable sites for wind turbines. Topics and procedures are also discussed that are important in carrying out a wind turbine siting program. These topics include: a description of the Department of Energy wind resource atlases; procedures for predicting wind turbine performance at potential sites; methods for analyzing wind turbine economics; procedures for estimating installation and maintenance costs; methods for anlayzing the distribution of wind resources over an area; and instrumentation for documenting wind behavior at potential sites. The procedure described is applicable to small and large utilities. Although the procedure was developed as a site-selection tool, it can also be used by a utility who wishes to estimate the potential for wind turbine penetration into its future generation mix.