WorldWideScience

Sample records for residual contaminant plume

  1. Groundwater contaminant plume ranking

    International Nuclear Information System (INIS)

    1988-08-01

    Containment plumes at Uranium Mill Tailings Remedial Action (UMTRA) Project sites were ranked to assist in Subpart B (i.e., restoration requirements of 40 CFR Part 192) compliance strategies for each site, to prioritize aquifer restoration, and to budget future requests and allocations. The rankings roughly estimate hazards to the environment and human health, and thus assist in determining for which sites cleanup, if appropriate, will provide the greatest benefits for funds available. The rankings are based on the scores that were obtained using the US Department of Energy's (DOE) Modified Hazard Ranking System (MHRS). The MHRS and HRS consider and score three hazard modes for a site: migration, fire and explosion, and direct contact. The migration hazard mode score reflects the potential for harm to humans or the environment from migration of a hazardous substance off a site by groundwater, surface water, and air; it is a composite of separate scores for each of these routes. For ranking the containment plumes at UMTRA Project sites, it was assumed that each site had been remediated in compliance with the EPA standards and that relict contaminant plumes were present. Therefore, only the groundwater route was scored, and the surface water and air routes were not considered. Section 2.0 of this document describes the assumptions and procedures used to score the groundwater route, and Section 3.0 provides the resulting scores for each site. 40 tabs

  2. Microbial populations in contaminant plumes

    Science.gov (United States)

    Haack, Sheridan K.; Bekins, Barbara A.

    Efficient biodegradation of subsurface contaminants requires two elements: (1) microbial populations with the necessary degradative capabilities, and (2) favorable subsurface geochemical and hydrological conditions. Practical constraints on experimental design and interpretation in both the hydrogeological and microbiological sciences have resulted in limited knowledge of the interaction between hydrogeological and microbiological features of subsurface environments. These practical constraints include: (1) inconsistencies between the scales of investigation in the hydrogeological and microbiological sciences, and (2) practical limitations on the ability to accurately define microbial populations in environmental samples. However, advances in application of small-scale sampling methods and interdisciplinary approaches to site investigations are beginning to significantly improve understanding of hydrogeological and microbiological interactions. Likewise, culture-based and molecular analyses of microbial populations in subsurface contaminant plumes have revealed significant adaptation of microbial populations to plume environmental conditions. Results of recent studies suggest that variability in subsurface geochemical and hydrological conditions significantly influences subsurface microbial-community structure. Combined investigations of site conditions and microbial-community structure provide the knowledge needed to understand interactions between subsurface microbial populations, plume geochemistry, and contaminant biodegradation. La biodégradation efficace des polluants souterrains requiert deux éléments: des populations microbiennes possédant les aptitudes nécessaires à la dégradation, et des conditions géochimiques et hydrologiques souterraines favorables. Des contraintes pratiques sur la conception et l'interprétation des expériences à la fois en microbiologie et en hydrogéologie ont conduit à une connaissance limitée des interactions entre les

  3. Modeling contaminant plumes in fractured limestone aquifers

    DEFF Research Database (Denmark)

    Mosthaf, Klaus; Brauns, Bentje; Fjordbøge, Annika Sidelmann

    Determining the fate and transport of contaminant plumes from contaminated sites in limestone aquifers is important because they are a major drinking water resource. This is challenging because they are often heavily fractured and contain chert layers and nodules, resulting in a complex transport...... model. The paper concludes with recommendations on how to identify and employ suitable models to advance the conceptual understanding and as decision support tools for risk assessment and the planning of remedial actions....... behavior. Improved conceptual models are needed for this type of site. Here conceptual models are developed by combining numerical models with field data. Several types of fracture flow and transport models are available for the modeling of contaminant transport in fractured media. These include...... the established approaches of the equivalent porous medium, discrete fracture and dual continuum models. However, these modeling concepts are not well tested for contaminant plume migration in limestone geologies. Our goal was to develop and evaluate approaches for modeling the transport of dissolved contaminant...

  4. Wireless Sensor Network Based Subsurface Contaminant Plume Monitoring

    Science.gov (United States)

    2012-04-16

    Sensor Network (WSN) to monitor contaminant plume movement in naturally heterogeneous subsurface formations to advance the sensor networking based...time to assess the source and predict future plume behavior. This proof-of-concept research aimed at demonstrating the use of an intelligent Wireless

  5. The use of sparge curtains for contaminant plume control

    International Nuclear Information System (INIS)

    Molnaa, B.; Dablow, J.

    1994-01-01

    Contamination by petroleum hydrocarbons and organic solvents represents a major impact to soil and groundwater. Following recent research and development, several technologies have evolved to treat saturated zone adsorbed- and dissolved-phase contaminants in situ. These technologies include bioremediation and air sparging. Funnel and gate approaches have been developed at the Waterloo Center for Groundwater Research to control contaminant plume migration and treat dissolved-phase contaminants before allowing migration downgradient and off site. The process consists of using low hydraulic conductivity cutoff walls to funnel groundwater flow through gates that contain in situ bioreactors. These systems can maintain hydraulic control and treat dissolved-phase contaminants at the downgradient margins of plumes, while minimizing, or in some cases eliminating, the need for groundwater pumping. Sparge curtains can be applied to treat dissolved-phase contaminants and prevent downgradient, off-site migration of contaminated groundwater

  6. Contaminant plumes containment and remediation focus area. Technology summary

    International Nuclear Information System (INIS)

    1995-06-01

    EM has established a new approach to managing environmental technology research and development in critical areas of interest to DOE. The Contaminant Plumes Containment and Remediation (Plumes) Focus Area is one of five areas targeted to implement the new approach, actively involving representatives from basic research, technology implementation, and regulatory communities in setting objectives and evaluating results. This document presents an overview of current EM activities within the Plumes Focus Area to describe to the appropriate organizations the current thrust of the program and developing input for its future direction. The Plumes Focus Area is developing remediation technologies that address environmental problems associated with certain priority contaminants found at DOE sites, including radionuclides, heavy metals, and dense non-aqueous phase liquids (DNAPLs). Technologies for cleaning up contaminants of concern to both DOE and other federal agencies, such as volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs), and other organics and inorganic compounds, will be developed by leveraging resources in cooperation with industry and interagency programs

  7. Contaminant plumes containment and remediation focus area. Technology summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    EM has established a new approach to managing environmental technology research and development in critical areas of interest to DOE. The Contaminant Plumes Containment and Remediation (Plumes) Focus Area is one of five areas targeted to implement the new approach, actively involving representatives from basic research, technology implementation, and regulatory communities in setting objectives and evaluating results. This document presents an overview of current EM activities within the Plumes Focus Area to describe to the appropriate organizations the current thrust of the program and developing input for its future direction. The Plumes Focus Area is developing remediation technologies that address environmental problems associated with certain priority contaminants found at DOE sites, including radionuclides, heavy metals, and dense non-aqueous phase liquids (DNAPLs). Technologies for cleaning up contaminants of concern to both DOE and other federal agencies, such as volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs), and other organics and inorganic compounds, will be developed by leveraging resources in cooperation with industry and interagency programs.

  8. Directional phytoscreening: contaminant gradients in trees for plume delineation.

    Science.gov (United States)

    Limmer, Matt A; Shetty, Mikhil K; Markus, Samantha; Kroeker, Ryan; Parker, Beth L; Martinez, Camilo; Burken, Joel G

    2013-08-20

    Tree sampling methods have been used in phytoscreening applications to delineate contaminated soil and groundwater, augmenting traditional investigative methods that are time-consuming, resource-intensive, invasive, and costly. In the past decade, contaminant concentrations in tree tissues have been shown to reflect the extent and intensity of subsurface contamination. This paper investigates a new phytoscreening tool: directional tree coring, a concept originating from field data that indicated azimuthal concentrations in tree trunks reflected the concentration gradients in the groundwater around the tree. To experimentally test this hypothesis, large diameter trees were subjected to subsurface contaminant concentration gradients in a greenhouse study. These trees were then analyzed for azimuthal concentration gradients in aboveground tree tissues, revealing contaminant centroids located on the side of the tree nearest the most contaminated groundwater. Tree coring at three field sites revealed sufficiently steep contaminant gradients in trees reflected nearby groundwater contaminant gradients. In practice, trees possessing steep contaminant gradients are indicators of steep subsurface contaminant gradients, providing compass-like information about the contaminant gradient, pointing investigators toward higher concentration regions of the plume.

  9. Organic contaminants in thermal plume resident brown trout

    International Nuclear Information System (INIS)

    Romberg, G.P.; Bourne, S.

    1978-01-01

    A pilot study was conducted to identify possible contaminants accumulated by thermal plume-resident fish in Lake Michigan. Brown trout were maintained in tanks receiving intake and discharge (less than or equal to 21 0 C) water from a power plant and were fed a diet of frozen alewife. Fish were sampled over a period of 127 days in order to estimate uptake rates and equilibrium levels for toxic organic and inorganic materials occurring in Lake Michigan fish and water. Experimental fish and natural samples were analyzed to determine the distribution of contaminants in various tissues and the corresponding pollutant levels in similar size brown trout from Lake Michigan. The quantitative analyses for the major organic contaminants are summarized. Without exception, the pyloric caecum of brown trout contained the highest concentration of lipids, PCB's, and chlorinated pesticides. Gill and kidney samples contained lower concentrations of contaminants than the caecum, while liver and muscle values were lowest

  10. Source-term development for a contaminant plume for use by multimedia risk assessment models

    International Nuclear Information System (INIS)

    Whelan, Gene; McDonald, John P.; Taira, Randal Y.; Gnanapragasam, Emmanuel K.; Yu, Charley; Lew, Christine S.; Mills, William B.

    1999-01-01

    Multimedia modelers from the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE) are collaborating to conduct a comprehensive and quantitative benchmarking analysis of four intermedia models: DOE's Multimedia Environmental Pollutant Assessment System (MEPAS), EPA's MMSOILS, EPA's PRESTO, and DOE's RESidual RADioactivity (RESRAD). These models represent typical analytically, semi-analytically, and empirically based tools that are utilized in human risk and endangerment assessments for use at installations containing radioactive and/or hazardous contaminants. Although the benchmarking exercise traditionally emphasizes the application and comparison of these models, the establishment of a Conceptual Site Model (CSM) should be viewed with equal importance. This paper reviews an approach for developing a CSM of an existing, real-world, Sr-90 plume at DOE's Hanford installation in Richland, Washington, for use in a multimedia-based benchmarking exercise bet ween MEPAS, MMSOILS, PRESTO, and RESRAD. In an unconventional move for analytically based modeling, the benchmarking exercise will begin with the plume as the source of contamination. The source and release mechanism are developed and described within the context of performing a preliminary risk assessment utilizing these analytical models. By beginning with the plume as the source term, this paper reviews a typical process and procedure an analyst would follow in developing a CSM for use in a preliminary assessment using this class of analytical tool

  11. Resolving superimposed ground-water contaminant plumes characterized by chromium, nitrate, uranium, and technetium--99

    International Nuclear Information System (INIS)

    Hall, S.H.

    1990-02-01

    Leakage from a liquid waste storage and solar evaporation basin at the Hanford Site in southeastern Washington State has resulted in a ground-water contaminant plume characterized by nitrate, hexavalent chromium, uranium, and technetium-99. The plume is superimposed on a larger, pre-existing plume extending from upgradient sites and having the same suite of contaminants. However, the relative abundance of contaminant species is quite different for each plume source. Thus, characteristic concentration ratios, rather than concentrations of individual species, are used as geochemical tracers, with emphasis on graphical analysis. Accordingly, it has been possible to resolve the boundaries of the smaller plume and to estimate the contribution of each plume to the observed contamination downgradient from the storage basin. 11 refs., 7 figs

  12. Groundwater redox conditions and conductivity in a contaminant plume from geoelectrical investigations

    Directory of Open Access Journals (Sweden)

    V. Naudet

    2004-01-01

    Full Text Available Accurate mapping of the electrical conductivity and of the redox potential of the groundwater is important in delineating the shape of a contaminant plume. A map of redox potential in an aquifer is indicative of biodegradation of organic matter and of concentrations of redox-active components; a map of electrical conductivity provides information on the mineralisation of the groundwater. Both maps can be used to optimise the position of pumping wells for remediation. The self-potential method (SP and electrical resistivity tomography (ERT have been applied to the contaminant plume associated with the Entressen landfill in south-east France. The self-potential depends on groundwater flow (electrokinetic contribution and redox conditions ('electro-redox' contribution. Using the variation of the piezometric head in the aquifer, the electrokinetic contribution is removed from the SP signals. A good linear correlation (R2=0.85 is obtained between the residual SP data and the redox potential values measured in monitoring wells. This relationship is used to draw a redox potential map of the overall contaminated site. The electrical conductivity of the subsoil is obtained from 3D-ERT analysis. A good linear correlation (R2=0.91 is observed between the electrical conductivity of the aquifer determined from the 3D-ERT image and the conductivity of the groundwater measured in boreholes. This indicates that the formation factor is nearly homogeneous in the shallow aquifer at the scale of the ERT. From this correlation, a map of the pore water conductivity of the aquifer is obtained. Keywords: self-potential, redox potential, electrical resistivity tomography, fluid conductivity, contaminant plume

  13. Consolidation of the landfill stabilization and contaminant plumes focus areas

    International Nuclear Information System (INIS)

    Brown, J.P.; Wright, J.; Chamberlain, G.S.

    1996-01-01

    The Assistant Secretary of the Office of Environmental Management (EM) on January 25, 1994, formally established five focus areas to implement A New Approach to Environmental Research and Technology Development at the U. S. Department of Energy (DOE) - Action Plan. The goal of this new approach was to conduct a research and technology development program that is focused on overcoming the major obstacles to cleaning up DOE sites and ensuring that the best talent within the Department and the national science communities is used. Two of the five focus areas established were Landfill Stabilization Focus Area (LSFA) and Contaminant Plumes Containment and Remediation Focus Area (PFA), which were located at the Savannah River Operations Office (SR)

  14. Contaminant plume configuration and movement: an experimental model

    Science.gov (United States)

    Alencoao, A.; Reis, A.; Pereira, M. G.; Liberato, M. L. R.; Caramelo, L.; Amraoui, M.; Amorim, V.

    2009-04-01

    The relevance of Science and Technology in our daily routines makes it compulsory to educate citizens who have both scientific literacy and scientific knowledge. These will allow them to be intervening citizens in a constantly changing society. Thus, physical and natural sciences are included in school curricula, both in primary and secondary education, with the fundamental aim of developing in the students the skills, attitudes and knowledge needed for the understanding of the planet Earth and its real problems. On the other hand, teaching in Geosciences is more and more based on practical methodologies which use didactic material, sustaining teachers' pedagogical practices and facilitating students' learning tasks suggested on the syllabus defined for each school level. Themes related to exploring the different components of the Hydrological Cycle and themes related to natural environment protection and preservation, namely water resources and soil contamination by industrial and urban sewage are examples of subject matters included on the Portuguese syllabus. These topics motivated the conception and construction of experimental models for the study of the propagation of pollutants on a porous medium. The experimental models allow inducing a horizontal flux of water though different kinds of permeable substances (e.g. sand, silt), with contamination spots on its surface. These experimental activities facilitate the student to understand the flow path of contaminating substances on the saturated zone and to observe the contaminant plume configuration and movement. The activities are explored in a teaching and learning process perspective where the student builds its own knowledge through real question- problem based learning which relate Science, Technology and Society. These activities have been developed in the framework of project ‘Water in the Environment' (CV/PVI/0854) of the POCTI Program (Programa Operacional "Ciência, Tecnologia, Inovação") financed

  15. Modelling tools for integrating geological, geophysical and contamination data for characterization of groundwater plumes

    DEFF Research Database (Denmark)

    Balbarini, Nicola

    the contaminant plume in a shallow and a deep plume. These plumes have different chemical characteristics and different migration paths to the stream. This has implications for the risk assessment of the stream and groundwater in the area. The difficulty of determining groundwater flow paths means that it is also...... receptors, including streams. Key risk assessment parameters, such as contaminant mass discharge estimates, and tools are then used to evaluate the risk. The cost of drilling often makes investigations of large and/or deep contaminant plumes unfeasible. For this reason, it is important to develop cost...... organic compounds, including pharmaceutical compounds and chlorinated ethenes. The correlation between DCIP and organic compounds is indirect and depends on the chemical composition of the contaminant plume and the transport processes. Thus, the correlations are site specific and may change between...

  16. Contaminant transport at a waste residue deposit

    DEFF Research Database (Denmark)

    Engesgaard, Peter Knudegaard; Traberg, Rikke

    1996-01-01

    Contaminant transport in an aquifer at an incinerator waste residue deposit in Denmark is simulated. A two-dimensional, geochemical transport code is developed for this purpose and tested by comparison to results from another code, The code is applied to a column experiment and to the field site...

  17. Model Intercomparison Study to Investigate a Dense Contaminant Plume in a Complex Hydrogeologic System

    International Nuclear Information System (INIS)

    Williams, Mark D.; Cole, Charles R.; Foley, Michael G.; Zinina, Galina A.; Zinin, Alexander I.; Vasil'Kova, Nelly A.; Samsonova, Lilia M.

    2001-01-01

    A joint Russian and U.S. model intercomparison study was undertaken for developing more realistic contaminant transport models of the Mayak Site, Southern Urals. The test problems were developed by the Russian Team based on their experience modeling contaminant migration near Lake Karachai. The intercomparison problems were designed to address lake and contaminant plume interactions, as well as river interactions and plume density effects. Different numerical codes were used. Overall there is good agreement between the results of both models. Features shown by both models include (1) the sinking of the plume below the lake, (2) the raising of the water table in the fresh water adjacent to the lake in response to the increased pressure from the dense plume, and (3) the formation of a second sinking plume in an area where evapotranspiration exceeded infiltration, thus increasing the solute concentrations above the source (i.e., lake) values

  18. Characterization of redox conditions in groundwater contaminant plumes

    Science.gov (United States)

    Christensen, Thomas H.; Bjerg, Poul L.; Banwart, Steven A.; Jakobsen, Rasmus; Heron, Gorm; Albrechtsen, Hans-Jørgen

    2000-10-01

    Evaluation of redox conditions in groundwater pollution plumes is often a prerequisite for understanding the behaviour of the pollutants in the plume and for selecting remediation approaches. Measuring of redox conditions in pollution plumes is, however, a fairly recent issue and yet relative few cases have been reported. No standardised or generally accepted approach exists. Slow electrode kinetics and the common lack of internal equilibrium of redox processes in pollution plumes make, with a few exceptions, direct electrochemical measurement and rigorous interpretation of redox potentials dubious, if not erroneous. Several other approaches have been used in addressing redox conditions in pollution plumes: redox-sensitive compounds in groundwater samples, hydrogen concentrations in groundwater, concentrations of volatile fatty acids in groundwater, sediment characteristics and microbial tools, such as MPN counts, PLFA biomarkers and redox bioassays. This paper reviews the principles behind the different approaches, summarizes methods used and evaluates the approaches based on the experience from the reported applications.

  19. Numerical Speadsheet Modeling of Natural Attenuation for Groundwater Contaminant Plumes

    National Research Council Canada - National Science Library

    Twesme, Troy

    1999-01-01

    .... The model was used to evaluate natural attenuation for removal of a trichloroethylene (TCE) plume from a surficial aquifer containing three regions with distinctly different processes for degradation of TCE...

  20. Detection of contaminant plumes released from landfills : Numerical versus analytical solutions

    NARCIS (Netherlands)

    Yenigül, N.B.; Hensbergen, A.T.; Elfeki, A.M.M.; Dekking, F.M.

    2011-01-01

    Contaminant leaks released from landfills are a threat to groundwater quality. The groundwater monitoring systems installed in the vicinity of such facilities are vital. In this study the detection probability of a contaminant plume released from a landfill has been investigated by means of both a

  1. Modeling Emissions and Vertical Plume Transport of Crop Residue Burning Experiments in the Pacific Northwest

    Science.gov (United States)

    Zhou, L.; Baker, K. R.; Napelenok, S. L.; Pouliot, G.; Elleman, R. A.; ONeill, S. M.; Urbanski, S. P.; Wong, D. C.

    2017-12-01

    Crop residue burning has long been a common practice in agriculture with the smoke emissions from the burning linked to negative health impacts. A field study in eastern Washington and northern Idaho in August 2013 consisted of multiple burns of well characterized fuels with nearby surface and aerial measurements including trace species concentrations, plume rise height and boundary layer structure. The chemical transport model CMAQ (Community Multiscale Air Quality Model) was used to assess the fire emissions and subsequent vertical plume transport. The study first compared assumptions made by the 2014 National Emission Inventory approach for crop residue burning with the fuel and emissions information obtained from the field study and then investigated the sensitivity of modeled carbon monoxide (CO) and PM2.5 concentrations to these different emission estimates and plume rise treatment with CMAQ. The study suggests that improvements to the current parameterizations are needed in order for CMAQ to reliably reproduce smoke plumes from burning. In addition, there is enough variability in the smoke emissions, stemming from variable field-specific information such as field size, that attempts to model crop residue burning should use field-specific information whenever possible.

  2. A mise-a'-la-masse method for landfill contaminant plume evaluation

    International Nuclear Information System (INIS)

    Rowley, T.H.; Donaldson, P.R.; Osiensky, J.L.; Welham, J.A.

    1994-01-01

    A mise-a'-la-masse survey was conducted down gradient of the Bannock County Landfill, in Fort Hall Canyon, Idaho in 1993. Data collected during the survey were compared to seismic refraction data also collected at the site. The site at the mouth of Fort Hall Canyon is ideal for use of the mise-a'-la-masse method to characterize a contaminant plume under actual field conditions. A contaminant plume is believed to emanate from the Bannock County Landfill. The plume contains high concentrations of Dense Non-Aqueous Phase Liquids (DNAPLs) plus inorganic groundwater contaminants. These DNAPLs and inorganics have been detected in nearby domestic and municipal water supply wells. The field site is relatively free of cultural interference that would adversely affect electrical-potential fields. 18 refs., 4 figs

  3. Air-Seawater Exchange of Organochlorine Pesticides along the Sediment Plume of a Large Contaminated River.

    Science.gov (United States)

    Lin, Tian; Guo, Zhigang; Li, Yuanyuan; Nizzetto, Luca; Ma, Chuanliang; Chen, Yingjun

    2015-05-05

    Gaseous exchange fluxes of organochlorine pesticides (OCPs) across the air-water interface of the coastal East China Sea were determined in order to assess whether the contaminated plume of the Yangtze River could be an important regional source of OCPs to the atmosphere. Hexachlorocyclohexanes (HCHs), chlordane compounds (CHLs), and dichlorodiphenyltrichloroethanes (DDTs) were the most frequently detected OCPs in air and water. Air-water exchange was mainly characterized by net volatilization for all measured OCPs. The net gaseous exchange flux ranged 10-240 ng/(m2·day) for γ-HCH, 60-370 ng/(m2·day) for trans-CHL, 97-410 ng/(m2·day) for cis-CHL, and ∼0 (e.g., equilibrium) to 490 ng/(m2·day) for p,p'-DDE. We found that the plume of the large contaminated river can serve as a significant regional secondary atmospheric source of legacy contaminants released in the catchment. In particular, the sediment plume represented the relevant source of DDT compounds (especially p,p'-DDE) sustaining net degassing when clean air masses from the open ocean reached the plume area. In contrast, a mass balance showed that, for HCHs, contaminated river discharge (water and sediment) plumes were capable of sustaining volatilization throughout the year. These results demonstrate the inconsistencies in the fate of HCHs and DDTs in this large estuarine system with declining primary sources.

  4. Delineation of contaminant plume for an inorganic contaminated site using electrical resistivity tomography: comparison with direct-push technique.

    Science.gov (United States)

    Liao, Qing; Deng, Yaping; Shi, Xiaoqing; Sun, Yuanyuan; Duan, Weidong; Wu, Jichun

    2018-03-03

    Precise delineation of contaminant plume distribution is essential for effective remediation of contaminated sites. Traditional in situ investigation methods like direct-push (DP) sampling are accurate, but are usually intrusive and costly. Electrical resistivity tomography (ERT) method, as a non-invasive geophysical technique to map spatiotemporal changes in resistivity of the subsurface, is becoming increasingly popular in environmental science. However, the resolution of ERT for delineation of contaminant plumes still remains controversial. In this study, ERT and DP technique were both conducted at a real inorganic contaminated site. The reliability of the ERT method was validated by the direct comparisons of their investigation results that the resistivity acquired by ERT method is in accordance with the total dissolved solid concentration in groundwater and the overall variation of the total iron content in soil obtained by DP technique. After testifying the applicability of ERT method for contaminant identification, the extension of contaminant plume at the study site was revealed by supplementary ERT surveys conducted subsequently in the surrounding area of the contaminant source zone.

  5. Remediating Contaminant Plumes in Groundwater with Shallow Excavations Containing Coarse Reactive Media.

    Science.gov (United States)

    Hudak, Paul F

    2018-02-01

    A groundwater flow and mass transport model tested the capability of shallow excavations filled with coarse, reactive media to remediate a hypothetical unconfined aquifer with a maximum saturated thickness of 5 m. Modeled as contaminant sinks, the rectangular excavations were 10 m downgradient of an initial contaminant plume originating from a source at the top of the aquifer. The initial plume was approximately 259 m long, 23 m wide, and 5 m thick, with a downgradient tip located approximately 100 m upgradient of the site boundary. The smallest trench capable of preventing offsite migration was 11 m long (measured perpendicular to groundwater flow), 4 m wide (measured parallel to groundwater flow), and 3 m deep. Results of this study suggest that shallow trenches filled with coarse filter media that partially penetrate unconfined aquifers may be a viable alternative for remediating contaminated groundwater at some sites.

  6. Groundwater contaminant plume maps and volumes, 100-K and 100-N Areas, Hanford Site, Washington

    Science.gov (United States)

    Johnson, Kenneth H.

    2016-09-27

    This study provides an independent estimate of the areal and volumetric extent of groundwater contaminant plumes which are affected by waste disposal in the 100-K and 100-N Areas (study area) along the Columbia River Corridor of the Hanford Site. The Hanford Natural Resource Trustee Council requested that the U.S. Geological Survey perform this interpolation to assess the accuracy of delineations previously conducted by the U.S. Department of Energy and its contractors, in order to assure that the Natural Resource Damage Assessment could rely on these analyses. This study is based on previously existing chemical (or radionuclide) sampling and analysis data downloaded from publicly available Hanford Site Internet sources, geostatistically selected and interpreted as representative of current (from 2009 through part of 2012) but average conditions for groundwater contamination in the study area. The study is limited in scope to five contaminants—hexavalent chromium, tritium, nitrate, strontium-90, and carbon-14, all detected at concentrations greater than regulatory limits in the past.All recent analytical concentrations (or activities) for each contaminant, adjusted for radioactive decay, non-detections, and co-located wells, were converted to log-normal distributions and these transformed values were averaged for each well location. The log-normally linearized well averages were spatially interpolated on a 50 × 50-meter (m) grid extending across the combined 100-N and 100-K Areas study area but limited to avoid unrepresentative extrapolation, using the minimum curvature geostatistical interpolation method provided by SURFER®data analysis software. Plume extents were interpreted by interpolating the log-normally transformed data, again using SURFER®, along lines of equal contaminant concentration at an appropriate established regulatory concentration . Total areas for each plume were calculated as an indicator of relative environmental damage. These plume

  7. Emplacement of zero-valent metal for remediation of deep contaminant plumes

    International Nuclear Information System (INIS)

    Hubble, D.W.; Gillham, R.W.; Cherry, J.A.

    1997-01-01

    Some groundwater plumes containing chlorinated solvent contaminants are found to be so deep that current in situ remediation technologies cannot be economically applied. Also, source zones are often found to be too deep for removal or inaccessible due to surface features. Plumes emanating from these sources require containment or treatment. Containment technologies are available for shallow sites (< 15 m) and are being developed for greater depths. However, it is important to advance the science of reactive treatment - both for cut off of plumes and to contain and treat source zones. Zero-valent metal technology has been used for remediation of solvent plumes at sites in Canada, the UK and at several industrial and military sites in the USA. To date, all of the plumes treated with zero-valent metal (granular iron) have been at depths less than 15 m. This paper gives preliminary results of research into methods to emplace granular iron at depths in the range of 15 to 60 m. The study included review of available and emerging methods of installing barrier or reactive material and the selection, preliminary design and costing of several methods. The design of a treatment system for a 122 m wide PCE plume that, immediately down gradient from its source, extends from a depth of 24 to 37 m below the ground surface is used as a demonstration site. Both Permeable Reactive Wall and Funnel-and-Gate trademark systems were considered. The emplacement methods selected for preliminary design and costing were slurry wall, driven/vibrated beam, deep soil mixing and hydrofracturing injection. For each of these methods, the iron must be slurried for ease of pumping and placement using biodegradable polymer viscosifiers that leave the iron reactive

  8. Maximum entropy estimation of a Benzene contaminated plume using ecotoxicological assays

    International Nuclear Information System (INIS)

    Wahyudi, Agung; Bartzke, Mariana; Küster, Eberhard; Bogaert, Patrick

    2013-01-01

    Ecotoxicological bioassays, e.g. based on Danio rerio teratogenicity (DarT) or the acute luminescence inhibition with Vibrio fischeri, could potentially lead to significant benefits for detecting on site contaminations on qualitative or semi-quantitative bases. The aim was to use the observed effects of two ecotoxicological assays for estimating the extent of a Benzene groundwater contamination plume. We used a Maximum Entropy (MaxEnt) method to rebuild a bivariate probability table that links the observed toxicity from the bioassays with Benzene concentrations. Compared with direct mapping of the contamination plume as obtained from groundwater samples, the MaxEnt concentration map exhibits on average slightly higher concentrations though the global pattern is close to it. This suggest MaxEnt is a valuable method to build a relationship between quantitative data, e.g. contaminant concentrations, and more qualitative or indirect measurements, in a spatial mapping framework, which is especially useful when clear quantitative relation is not at hand. - Highlights: ► Ecotoxicological shows significant benefits for detecting on site contaminations. ► MaxEnt to rebuild qualitative link on concentration and ecotoxicological assays. ► MaxEnt shows similar pattern when compared with concentrations map of groundwater. ► MaxEnt is a valuable method especially when quantitative relation is not at hand. - A Maximum Entropy method to rebuild qualitative relationships between Benzene groundwater concentrations and their ecotoxicological effect.

  9. Development of irradiation technique on controlling food contamination residue

    International Nuclear Information System (INIS)

    Liu Bin; Xiong Shanbai; Xiong Guangquan; Cheng Wei; Chen Yuxia; Liao Tao; Li Xin; Lin Ruotai

    2010-01-01

    The current state of the researches of irradiation technology on controlling food mycotoxin, pesticide, veterinary drugs and fishery drugs residue was summarized. And the degradation rate, mechanism, products and toxicities of food contamination were expatiated. The free radical from irradiation attack the site of weaker bond, and the less or more toxic substances were produced, which lead to the degradation of the food contamination. The limitations and future application of irradiation technique on controlling food contamination were also analyzed. (authors)

  10. Tracking the origin and dispersion of contaminated sediments transported by rivers draining the Fukushima radioactive contaminant plume

    Directory of Open Access Journals (Sweden)

    H. Lepage

    2015-03-01

    Full Text Available This study was conducted in several catchments draining the main Fukushima Dai-ichi Power Plant contaminant plume in Fukushima prefecture, Japan. We collected soils and sediment drape deposits (n = 128 and investigated the variation in 137Cs enrichment during five sampling campaigns, conducted every six months, which typically occurred after intense erosive events such as typhoons and snowmelt. We show that upstream contaminated soils are eroded during summer typhoons (June–October before being exported during the spring snowmelt (March–April. However, this seasonal cycle of sediment dispersion is further complicated by the occurrence of dam releases that may discharge large amounts of contaminants to the coastal plains during the coming years.

  11. Chemical speciation of radionuclides in contaminant plumes at the Chalk River Nuclear Laboratories

    International Nuclear Information System (INIS)

    Champ, D.R.

    1986-01-01

    Experimental disposals of liquid and glassified wastes directly into the sands of the Perch Lake basin, Ontario, Canada, have resulted in the formation of well-defined subsurface contaminant plumes in the groundwater flow system. Using large volume water sampling techniques we have detected low concentrations of several long-lived radionuclides including isotopes of Pu, Am, Cm, Tc, I, Sr and Cs. The particulate and ionic speciation results from these studies support the conclusions of previous laboratory column studies that transport of radionuclides, particularly Cs and Pu, on particulates and/or colloids could be a significant mobilization mechanism in groundwater flow systems. We also propose, based on a comparison of the plume data with previous detailed studies on 60 Co that complexation reactions with natural as well as synthetic organic ligands can yield mobile anionic species of the actinides and lanthanides. Further detailed studies will be required to support this postulate. (author)

  12. The Biogeochemistry of Contaminant Groundwater Plumes Arising from Waste Disposal Facilities

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Albrechtsen, Hans-Jørgen; Kjeldsen, Peter

    2014-01-01

    Landfills with solid waste are abundant sources of groundwater pollution all over the world. Old uncontrolled municipal landfills are often large, heterogeneous sources with demolition waste, minor fractions of commercial or industrial waste, and organic waste from households. Strongly anaerobic...... leachate with a high content of dissolved organic carbon, salts, and ammonium, as well as specific organic compounds and metals is released from the waste for decades or centuries. Landfill leachate plume hosts a variety of biogeochemical processes, which is the key to understand the significant potential...... and the literature are the following: (1) Local hydrogeological conditions in the landfill area may affect the spreading of the contaminants; (2) investigations of landfill leachate plumes in geologic settings with clayey till deposits and fractured consolidated sediments are lacking; (3) the size of the landfill...

  13. Earthworm tolerance to residual agricultural pesticide contamination

    DEFF Research Database (Denmark)

    Givaudan, Nicolas; Binet, Françoise; Le Bot, Barbara

    2014-01-01

    of soluble glutathione-S-transferases (sGST) and catalase increased with soil pesticide contamination in A. caliginosa. Pesticide stress was reflected in depletion of energy reserves in A. chlorotica. Acute exposure of pre-adapted and naïve A. caliginosa to pesticides (fungicide Opus ®, 0.1 μg active...

  14. Release behavior of triazine residues in stabilised contaminated soils

    International Nuclear Information System (INIS)

    Ying, G.G.; Kookana, R.S.; Mallavarpu, M.

    2005-01-01

    This paper reports the release behavior of two triazines (atrazine and simazine) in stabilised soils from a pesticide-contaminated site in South Australia. The soils were contaminated with a range of pesticides, especially with triazine herbicides. With multiple extractions of each soil sample with deionised water (eight in total), 15% of atrazine and 4% of simazine residues were recovered, resulting in very high concentrations of the two herbicides in leachate. The presence of small fractions of surfactants was found to further enhance the release of the residues. Methanol content up to 10% did not substantially influence the concentration of simazine and atrazine released. The study demonstrated that while the stabilisation of contaminated soil with particulate activated carbon (5%) and cement mix (15%) was effective in locking the residues of some pesticides, it failed to immobilise triazine herbicides residues completely. Given the higher water solubility of these herbicides than other compounds more effective strategies to immobilise their residues is needed. - Stabilisation of contaminated soil with a mix of activated carbon and cement may fail to immobilise some contaminants like triazines

  15. 3-D spectral IP imaging: Non-invasive characterization of contaminant plumes. 1998 annual progress report

    International Nuclear Information System (INIS)

    Lesmes, D.; Morgan, F.D.; Rodi, W.

    1998-01-01

    'The overall objective of this project is to develop the scientific basis for characterizing contaminant plumes in the earth''s subsurface using field measurements of induced polarization (IP) effects. Three specific objectives towards this end are: (1) understanding IP at the laboratory level through measurements of complex resistivity as a function of frequency in rock and soil samples with varying pore geometries, pore fluid conductivities and saturations, and contaminant chemistries and concentrations; (2) developing effective data acquisition techniques for measuring the critical IP responses (time domain or frequency domain) in the field; (3) developing modeling and inversion algorithms that permit the interpretation of field IP data in terms of subsurface geology and contaminant plume properties. The authors laboratory experiments to date are described in Appendices A and B, which consist of two papers submitted to the annual SAGEEP conference (Frye et al., 1998; Sturrock et al., 1998). The experiments involved measurements of complex resistivity vs. frequency on a suite of brine saturated sandstone samples. In one set of experiments, the fluid chemistry (pH, ionic strength, and cation type) was varied. In a second set of experiments, the microgeometry of the rock matrix was varied. The experiments showed that spectral IP responses are sensitive to subtle variations in both the solution chemistry and rock microgeometry. The results demonstrate that spectral IP responses have the potential of being sensitive indicators of in-situ chemistry and microgeometry, the latter of which may be related to the hydraulic properties. Data Acquisition The authors have been looking in some detail at the effects of electromagnetic coupling and how to practically deal with it. In this area, the results to date are summarized in Vandiver (1998). The progress in the development of modeling and inversion algorithms for IP is described in Appendix C, a paper submitted to the

  16. Is the IP response related to geology or contaminants in a leachate plume at the Grindsted Landfill, Denmark?

    DEFF Research Database (Denmark)

    Møller, Ingelise; Maurya, Pradip Kumar; Balbarini, Nicola

    Contaminants in leachate plumes from landfills and other contaminated sites are a threat to the environment. Efficient site characterization methods are needed. The perspectives of the IP method are investigated in combination with geological sampling and chemical analyses of water samples. Along...... a leachate plume from a landfill hosting both household and chemical waste, borehole IP data, geological samples, grain size, and contaminant concentrations in water samples are examined for correlations related to geology and concentrations of contaminants. Results relating the Cole-Cole parameters...... with sediment types and pore water resistivity representing the concentrations of the contaminants show that the formation resistivity primarily is controlled by the contaminant concentrations while the IP parameters primarily are related to the clay content and grain size distribution of sandy sediments...

  17. Is the IP response related to geology or contaminants in a leachate plume at the Grindsted Landfill, Denmark?

    DEFF Research Database (Denmark)

    Møller, Ingelise; Maurya, Pradip Kumar; Balbarini, Nicola

    a leachate plume from a landfill hosting both household and chemical waste, borehole IP data, geological samples, grain size, and contaminant concentrations in water samples are examined for correlations related to geology and concentrations of contaminants. Results relating the Cole-Cole parameters...... with sediment types and pore water resistivity representing the concentrations of the contaminants show that the formation resistivity primarily is controlled by the contaminant concentrations while the IP parameters primarily are related to the clay content and grain size distribution of sandy sediments......Contaminants in leachate plumes from landfills and other contaminated sites are a threat to the environment. Efficient site characterization methods are needed. The perspectives of the IP method are investigated in combination with geological sampling and chemical analyses of water samples. Along...

  18. Is surgical plume developing during routine LEEPs contaminated with high-risk HPV? A pilot series of experiments.

    Science.gov (United States)

    Neumann, Kay; Cavalar, Markus; Rody, Achim; Friemert, Luisa; Beyer, Daniel A

    2018-02-01

    Growing evidence shows a causal role of high-risk humane papillomavirus (HPV) infections in the development of head and neck cancer. A recent case report shows two patients suffering from tonsillar cancer without any risk factors apart from their work as gynecologists doing laser ablations and loop electrosurgical excision procedures (LEEP). The aim of the present investigation is to evaluate whether surgical plume resulting from routine LEEPs of HSIL of the cervix uteri might be contaminated with the DNA of high-risk HPV. The prospective pilot study is done at the Department of Gynecology and Obstetrics of the University of Lübeck, Germany. The primary outcome was defined as HPV subtype in resected cone and in surgical plume resulting from LEEPs of HSIL of the cervix uteri. Plume resulting from LEEPs was analyzed using a Whatman FTA Elute Indicating Card which was placed in the tube of an exhaust suction device used to remove the resulting aerosols. For detection of HPV and analysis of its subtype, the novel EUROArray HPV test was performed. Resected cones of LEEPs were evaluated separately for HPV subtypes. Four samples of surgical plume resulting from routine LEEPs indicated contamination with high-risk HPV and showed the same HPV subtype as identified in the resected cones. Surgical plume resulting from routine LEEPs for HSIL of the cervix uteri has the risk of contamination with high-risk HPV. Further investigations of infectiousness of surgical plume are necessary for evaluation of potential hazards to involved healthcare professionals.

  19. Rapid intrinsic biodegradation of benzene, toluene, and xylenes at the boundary of a gasoline-contaminated plume under natural attenuation

    Energy Technology Data Exchange (ETDEWEB)

    Takahata, Yoh; Hoaki, Toshihiro [Taisei Corp., Yokohama (Japan). Civil Engineering Research Inst.; Kasai, Yuki; Watanabe, Kazuya [Marine Biotechnology Institute, Kamaishi (Japan)

    2006-12-15

    A groundwater plume contaminated with gasoline constituents [mainly benzene, toluene, and xylenes (BTX)] had been treated by pumping and aeration for approximately 10 years, and the treatment strategy was recently changed to monitored natural attenuation (MNA). To gain information on the feasibility of using MNA to control the spread of BTX, chemical and microbiological parameters in groundwater samples obtained inside and outside the contaminated plume were measured over the course of 73 weeks. The depletion of electron acceptors (i.e., dissolved oxygen, nitrate, and sulfate) and increase of soluble iron were observed in the contaminated zone. Laboratory incubation tests revealed that groundwater obtained immediately outside the contaminated zone (the boundary zone) exhibited much higher potential for BTX degradation than those in the contaminated zone and in uncontaminated background zones. The boundary zone was a former contaminated area where BTX were no longer detected. Denaturing gradient gel electrophoresis (DGGE) analysis of polymerase chain reaction (PCR)-amplified bacterial 16S rRNA gene fragments revealed that DGGE profiles for groundwater samples obtained from the contaminated zone were clustered together and distinct from those from uncontaminated zones. In addition, unique bacterial rRNA types were observed in the boundary zone. These results indicate that the boundary zone in the contaminant plumes served as a natural barrier for preventing the BTX contamination from spreading out. (orig.)

  20. Residual contamination and corrosion on electrochemically marked uranium

    International Nuclear Information System (INIS)

    Seals, R.D.; Bullock, J.S.; Bennett, R.K.

    1981-01-01

    Residual contamination and potential corrosion problems on uranium parts resulting from PHB-1 and PHB-1E electroetchants have been investigated using ion microprobe mass analysis (IMMA), scanning electron microscopy (SEM), and light microscopy (LM). The effectiveness of various solvent cleaning sequences and the influence of the use of an abrasive cleaner were evaluated. The marking thicknesses and chlorine distributions were determined

  1. Resistivity and self-potential tomography applied to groundwater remediation and contaminant plumes: Sandbox and field experiments

    Science.gov (United States)

    Mao, D.; Revil, A.; Hort, R. D.; Munakata-Marr, J.; Atekwana, E. A.; Kulessa, B.

    2015-11-01

    Geophysical methods can be used to remotely characterize contaminated sites and monitor in situ enhanced remediation processes. We have conducted one sandbox experiment and one contaminated field investigation to show the robustness of electrical resistivity tomography and self-potential (SP) tomography for these applications. In the sandbox experiment, we injected permanganate in a trichloroethylene (TCE)-contaminated environment under a constant hydraulic gradient. Inverted resistivity tomograms are able to track the evolution of the permanganate plume in agreement with visual observations made on the side of the tank. Self-potential measurements were also performed at the surface of the sandbox using non-polarizing Ag-AgCl electrodes. These data were inverted to obtain the source density distribution with and without the resistivity information. A compact horizontal dipole source located at the front of the plume was obtained from the inversion of these self-potential data. This current dipole may be related to the redox reaction occurring between TCE and permanganate and the strong concentration gradient at the front of the plume. We demonstrate that time-lapse self-potential signals can be used to track the kinetics of an advecting oxidizer plume with acceptable accuracy and, if needed, in real time, but are unable to completely resolve the shape of the plume. In the field investigation, a 3D resistivity tomography is used to characterize an organic contaminant plume (resistive domain) and an overlying zone of solid waste materials (conductive domain). After removing the influence of the streaming potential, the identified source current density had a magnitude of 0.5 A m-2. The strong source current density may be attributed to charge movement between the neighboring zones that encourage abiotic and microbially enhanced reduction and oxidation reactions. In both cases, the self-potential source current density is located in the area of strong resistivity

  2. Hanford tank residual waste - Contaminant source terms and release models

    International Nuclear Information System (INIS)

    Deutsch, William J.; Cantrell, Kirk J.; Krupka, Kenneth M.; Lindberg, Michael L.; Jeffery Serne, R.

    2011-01-01

    Highlights: → Residual waste from five Hanford spent fuel process storage tanks was evaluated. → Gibbsite is a common mineral in tanks with high Al concentrations. → Non-crystalline U-Na-C-O-P ± H phases are common in the U-rich residual. → Iron oxides/hydroxides have been identified in all residual waste samples. → Uranium release is highly dependent on waste and leachant compositions. - Abstract: Residual waste is expected to be left in 177 underground storage tanks after closure at the US Department of Energy's Hanford Site in Washington State, USA. In the long term, the residual wastes may represent a potential source of contamination to the subsurface environment. Residual materials that cannot be completely removed during the tank closure process are being studied to identify and characterize the solid phases and estimate the release of contaminants from these solids to water that might enter the closed tanks in the future. As of the end of 2009, residual waste from five tanks has been evaluated. Residual wastes from adjacent tanks C-202 and C-203 have high U concentrations of 24 and 59 wt.%, respectively, while residual wastes from nearby tanks C-103 and C-106 have low U concentrations of 0.4 and 0.03 wt.%, respectively. Aluminum concentrations are high (8.2-29.1 wt.%) in some tanks (C-103, C-106, and S-112) and relatively low ( 2 -saturated solution, or a CaCO 3 -saturated water. Uranium release concentrations are highly dependent on waste and leachant compositions with dissolved U concentrations one or two orders of magnitude higher in the tests with high U residual wastes, and also higher when leached with the CaCO 3 -saturated solution than with the Ca(OH) 2 -saturated solution. Technetium leachability is not as strongly dependent on the concentration of Tc in the waste, and it appears to be slightly more leachable by the Ca(OH) 2 -saturated solution than by the CaCO 3 -saturated solution. In general, Tc is much less leachable (<10 wt.% of the

  3. Residues and contaminants in tea and tea infusions: a review.

    Science.gov (United States)

    Abd El-Aty, A M; Choi, Jeong-Heui; Rahman, Md Musfiqur; Kim, Sung-Woo; Tosun, Alev; Shim, Jae-Han

    2014-01-01

    Consumers are very aware of contaminants that could pose potential health hazards. Most people drink tea as an infusion (adding hot water); however, in some countries, including India, China and Egypt, tea is drunk as a decoction (tea and water are boiled together). An infusion usually brings the soluble ingredients into solution, whereas a decoction brings all soluble and non-soluble constituents together. Therefore, a cup of tea may contain various kinds of contaminants. This review focuses on green and black tea because they are most commonly consumed. The target was to examine the transfer rate of contaminants - pesticides, environmental pollutants, mycotoxins, microorganisms, toxic heavy metals, radioactive isotopes (radionuclides) and plant growth regulators - from tea to infusion/brewing, factors contributing to the transfer potential and contaminants degradation, and residues in or on the spent leaves. It is concluded that most contaminants leaching into tea infusion are not detected or are detected at a level lower than the regulatory limits. However, the traditional practice of over-boiling tea leaves should be discouraged as there may be a chance for more transfer of contaminants from the tea to the brew.

  4. Residual radioactive contamination at Maralinga and Emu, 1985

    International Nuclear Information System (INIS)

    Lokan, K.H.

    1985-04-01

    An account is provided of residual contamination at Maralinga and Emu, in South Australia, where the United Kingdom Atomic Weapons Research Establishment conducted nuclear weapons development trials between 1953 and 1963. Detailed information is presented about contamination levels at sites on the range where radioactive materials were dispersed. Some of these were associated with trials involving natural uranium or short-lived isotopes which are no longer present. There are four sites where plutonium-239 was dispersed in substantial quantities from minor trials and information is presented about its distribution. Much of this material has been diluted by mixing with local soil, but there is a significant quantity of material present in the form of contaminated fragments, particularly at Taranaki. A considerable quantity of uranium-235 is also present at Taranaki. An assessment is made of the radiological significance of the dispersed plutonium and it is concluded that the material represents a potential long term hazard while it remains in its present form. Residual radioactivity associated with all but one of the seven major trial sites involving nuclear explosions continues to decay in a predictable way and will in the worst case, fall below levels considered safe for continuous occupancy within about fifty years. One site, Tadje, contains significant concentrations of plutonium over a small area and onsidered to be an additional plutonium-contaminated locality. Measurements of beryllium concentrations in soil are presented

  5. Waste and cost reduction using dual wall reverse circulation drilling with multi-level groundwater sampling for contaminant plume delineation

    International Nuclear Information System (INIS)

    Smuin, D.R.

    1995-01-01

    This paper describes the drilling and sampling methods used to delineate a groundwater contaminant plume at the Paducah Gaseous Diffusion Plant (PGDP) during the Groundwater Monitoring IV characterization. The project was unique in that it relied upon dual wall reverse circulation drilling instead of the traditional hollow stem auger method. The Groundwater Monitoring program sought to characterize the boundaries, both vertically and horizontally, of the northeast plume which contains both 99 Tc and trichloroethene. This paper discusses the strengths and weaknesses of the drilling method used by investigators

  6. Stormwater Runoff Plumes in Southern California Detected with Satellite SAR and MODIS Imagery - Areas of Increased Contamination Risk

    Science.gov (United States)

    Trinh, R. C.; Holt, B.; Gierach, M.

    2016-12-01

    Coastal pollution poses both a major health and environmental hazard, not only for beachgoers and coastal communities, but for marine organisms as well. Stormwater runoff is the largest source of pollution in the coastal waters of the Southern California Bight (SCB). The SCB is the final destination of four major urban watersheds and associated rivers, Ballona Creek, the Los Angeles River, the San Gabriel River, and the Santa Ana River, which act as channels for runoff and pollution during and after episodic rainstorms. Previous studies of SCB water quality have made use of both fine resolution Synthetic Aperture Radar (SAR) imagery and wide-swath medium resolution optical "ocean color" imagery from SeaWiFS and MODIS. In this study, we expand on previous SAR efforts, compiling a more extensive collection of multi-sensor SAR data, spanning from 1992 to 2014, analyzing the surface slick component of stormwater plumes. We demonstrate the use of SAR data in early detection of coastal stormwater plumes, relating plume extent to cumulative river discharge, and shoreline fecal bacteria loads. Intensity maps of the primary extent and direction of plumes were created, identifying coastal areas that may be subject to the greatest risk of environmental contamination. Additionally, we illustrate the differences in the detection of SAR surface plumes with the sediment-related discharge plumes derived from MODIS ocean color imagery. Finally, we provide a concept for satellite monitoring of stormwater plumes, combining both optical and radar sensors, to be used to guide the collection of in situ water quality data and enhance the assessment of related beach closures.

  7. Analysis of Food Contaminants, Residues, and Chemical Constituents of Concern

    Science.gov (United States)

    Ismail, Baraem; Reuhs, Bradley L.; Nielsen, S. Suzanne

    The food chain that starts with farmers and ends with consumers can be complex, involving multiple stages of production and distribution (planting, harvesting, breeding, transporting, storing, importing, processing, packaging, distributing to retail markets, and shelf storing) (Fig. 18.1). Various practices can be employed at each stage in the food chain, which may include pesticide treatment, agricultural bioengineering, veterinary drug administration, environmental and storage conditions, processing applications, economic gain practices, use of food additives, choice of packaging material, etc. Each of these practices can play a major role in food quality and safety, due to the possibility of contamination with or introduction (intentionally and nonintentionally) of hazardous substances or constituents. Legislation and regulation to ensure food quality and safety are in place and continue to develop to protect the stakeholders, namely farmers, consumers, and industry. [Refer to reference (1) for information on regulations of food contaminants and residues.

  8. Role of rhizosphere microorganisms in phytoremediation of biphenyl in a contaminated groundwater plume

    International Nuclear Information System (INIS)

    Sun, B.; Ramsay, J.

    2007-01-01

    This presentation discussed a pump and treat technology used in combination with a phytoremediation technology to remediate a biphenyl contaminated groundwater plume. Biphenyl is used in industrial applications as fungicide and heat transfer agent. It is highly toxic, has poor water solubility and sorbs strongly to soils. Costs for the project were estimated at $860,000 over a period of 20 years, while it was estimated that the addition of phytoremediation would cost only $125,000 over a period of 20 years. The phytoremediation containment area was added to the site which was comprised of a pump and treat system and landfill lagoons. In situ biodegradation of biphenyl was evaluated using microorganisms in poplar and willow rhizospheres. Basal salts were used as a culture medium. Methods to enhance biphenyl degradation were also investigated. Aerobic growth on biphenyl at temperatures of 8 degrees C were measured, and microbial populations were identified. The consortium with the highest biphenyl degradation was then analyzed. Major members were identified as Burkholderia xenovorans LB400 and a strain of Burkholderia xenovorans. Nitrate reduction, sulphate reduction, and methanogens were measured. Enrichment of anaerobic biphenyl degraders. Anaerobic biphenyl degradation was measured after 90 days. Details of anaerobic mineralization experiments were also provided. It was concluded that anaerobic biphenyl degradation was enhanced by TEA and fertilizer addition, as well as by poplar root exudate. tabs., figs

  9. Long-term electrical resistivity monitoring of recharge-induced contaminant plume behavior.

    Science.gov (United States)

    Gasperikova, Erika; Hubbard, Susan S; Watson, David B; Baker, Gregory S; Peterson, John E; Kowalsky, Michael B; Smith, Meagan; Brooks, Scott

    2012-11-01

    Geophysical measurements, and electrical resistivity tomography (ERT) data in particular, are sensitive to properties that are related (directly or indirectly) to hydrological processes. The challenge is in extracting information from geophysical data at a relevant scale that can be used to gain insight about subsurface behavior and to parameterize or validate flow and transport models. Here, we consider the use of ERT data for examining the impact of recharge on subsurface contamination at the S-3 ponds of the Oak Ridge Integrated Field Research Challenge (IFRC) site in Tennessee. A large dataset of time-lapse cross-well and surface ERT data, collected at the site over a period of 12 months, is used to study time variations in resistivity due to changes in total dissolved solids (primarily nitrate). The electrical resistivity distributions recovered from cross-well and surface ERT data agrees well, and both of these datasets can be used to interpret spatiotemporal variations in subsurface nitrate concentrations due to rainfall, although the sensitivity of the electrical resistivity response to dilution varies with nitrate concentration. Using the time-lapse surface ERT data interpreted in terms of nitrate concentrations, we find that the subsurface nitrate concentration at this site varies as a function of spatial position, episodic heavy rainstorms (versus seasonal and annual fluctuations), and antecedent rainfall history. These results suggest that the surface ERT monitoring approach is potentially useful for examining subsurface plume responses to recharge over field-relevant scales. Published by Elsevier B.V.

  10. Residual radioactive contamination from decommissioning: Technical basis for translating contamination levels to annual dose

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Peloquin, R.A.

    1990-01-01

    This document describes the generic modeling of the total effective dose equivalent (TEDE) to an individual in a population from a unit concentration of residual radioactive contamination. Radioactive contamination inside buildings and soil contamination are considered. Unit concentration TEDE factors by radionuclide, exposure pathway, and exposure scenario are calculated. Reference radiation exposure scenarios are used to derive unit concentration TEDE factors for about 200 individual radionuclides and parent-daughter mixtures. For buildings, these unit concentration factors list the annual TEDE for volume and surface contamination situations. For soil, annual TEDE factors are presented for unit concentrations of radionuclides in soil during residential use of contaminated land and the TEDE per unit total inventory for potential use of drinking water from a ground-water source. Because of the generic treatment of potentially complex ground-water systems, the annual TEDE factors for drinking water for a given inventory may only indicate when additional site data or modeling sophistication are warranted. Descriptions are provided of the models, exposure pathways, exposure scenarios, parameter values, and assumptions used. An analysis of the potential annual TEDE resulting from reference mixtures of residual radionuclides is provided to demonstrate application of the TEDE factors. 62 refs., 5 figs., 66 tabs

  11. Coupling of Realistic Rate Estimates with Genomics for Assessing Contaminant Attenuation and Long-Term Plume Containment

    International Nuclear Information System (INIS)

    Sorenson, Kent S. Jr.

    2003-01-01

    Natural attenuation of TCE under aerobic conditions at the INEEL Test Area North site was demonstrated largely on the basis of preferential loss of TCE relative to conservative solutes (PCE and H-3) along groundwater flow paths. First order degradation half-lives were calculated from the rate of preferential TCE loss. We are utilizing the same approach at other DOE sites that have aerobic TCE plumes to determine if aerobic natural attenuation of TCE is rapid enough at these sites to be environmentally significant, i.e. if natural attenuation can reduce concentrations to acceptable levels before groundwater reaches potential receptors. The first step in this process was to identify TCE plumes at DOE sites that have the appropriate site conditions and data needed to perform this analysis. The site conditions include the presence of TCE in groundwater at appreciable concentrations in an aerobic aquifer, a co-mingled contaminant that can be used as a conservative tracer (e.g. PCE, H-3, Tc-99), a flow path that represents at least a decade of travel time, and several monitoring wells located along this flow path. Candidate sites were identified through interviews with knowledgeable individuals in the DOE system and by screening the U.S. Dept. of Energy Groundwater Database using the keywords ''TCE'' and ''groundwater''. The initial screening yielded 25 plumes for consideration. These sites had anywhere from one to 37 individual plumes containing TCE. Of the 25 sites, 13 sites were further evaluated because they met the screening criteria or were promising. After contacting DOE personnel from the respective sites, they were divided into three groups: (1) sites that meet all the project criteria, (2) sites that could potentially be used for the project, and (3) DOE sites that did not meet the criteria. The five sites with plumes that met the criteria were: Brookhaven National Laboratory, Lawrence Livermore National Laboratory, Paducah Gaseous Diffusion Plant, Rocky Flats

  12. A stable isotope approach for source apportionment of chlorinated ethene plumes at a complex multi-contamination events urban site

    Science.gov (United States)

    Nijenhuis, Ivonne; Schmidt, Marie; Pellegatti, Eleonora; Paramatti, Enrico; Richnow, Hans Hermann; Gargini, Alessandro

    2013-10-01

    The stable carbon isotope composition of chlorinated aliphatic compounds such as chlorinated methanes, ethanes and ethenes was examined as an intrinsic fingerprint for apportionment of sources. A complex field site located in Ferrara (Italy), with more than 50 years history of use of chlorinated aliphatic compounds, was investigated in order to assess contamination sources. Several contamination plumes were found in a complex alluvial sandy multi-aquifer system close to the river Po; sources are represented by uncontained former industrial and municipal dump sites as well as by spills at industrial areas. The carbon stable isotope signature allowed distinguishing 2 major sources of contaminants. One source of chlorinated aliphatic contaminants was strongly depleted in 13C (-40‰ which is commonly observed in recent production of chlorinated solvents. The degradation processes in the plumes could be traced interpreting the isotope enrichment and depletion of parent and daughter compounds, respectively. We demonstrate that, under specific production conditions, namely when highly chlorinated ethenes are produced as by-product during chloromethanes production, 13C depleted fingerprinting of contaminants can be obtained and this can be used to track sources and address the responsible party of the pollution in urban areas.

  13. Satellite infrared imagery for thermal plume contamination monitoring in coastal ecosystem of Cernavoda NPP

    Science.gov (United States)

    Zoran, M. A.; Zoran, Liviu Florin V.; Dida, Adrian I.

    2017-10-01

    Satellite remote sensing is an important tool for spatio-temporal analysis and surveillance of NPP environment, thermal heat waste of waters being a major concern in many coastal ecosystems involving nuclear power plants. As a test case the adopted methodology was applied for 700x2 MW Cernavoda nuclear power plant (NPP) located in the South-Eastern part of Romania, which discharges warm water affecting coastal ecology. The thermal plume signatures in the NPP hydrological system have been investigated based on TIR (Thermal Infrared) spectral bands of NOAA AVHRR, Landsat TM/ETM+/OLI, and MODIS Terra/Aqua time series satellite data during 1990-2016 period. If NOAA AVHRR data proved the general pattern and extension of the thermal plume signature in Danube river and Black Sea coastal areas, Landsat TM/ETM and MODIS data used for WST (Water Surface Temperature) change detection, mapping and monitoring provided enhanced information about the plume shape, dimension and direction of dispersion in these waters. Thermal discharge from two nuclear reactors cooling is dissipated as waste heat in Danube-Black -Sea Channel and Danube River. From time-series analysis of satellite data during period 1990-2016 was found that during the winter season thermal plume was localized to an area of a few km of NPP, and the mean temperature difference between the plume and non-plume areas was about 1.7 oC. During summer and fall, derived mean temperature difference between the plume and non-plume areas was of about 1.3°C and thermal plume area was extended up to 5- 10 km far along Danube Black Sea Channel.

  14. Modeling crop residue burning experiments to evaluate smoke emissions and plume transport

    Science.gov (United States)

    Crop residue burning is a common land management practice that results in emissions of a variety of pollutants with negative health impacts. Modeling systems are used to estimate air quality impacts of crop residue burning to support retrospective regulatory assessments and also ...

  15. Modeling crop residue burning experiments to evaluate smoke emissions and plume transport

    Science.gov (United States)

    Luxi Zhou; Kirk R. Baker; Sergey L. Napelenok; George Pouliot; Robert Elleman; Susan M. O' Neill; Shawn P. Urbanski; David C. Wong

    2018-01-01

    Crop residue burning is a common land management practice that results in emissions of a variety of pollutants with negative health impacts. Modeling systems are used to estimate air quality impacts of crop residue burning to support retrospective regulatory assessments and also for forecasting purposes. Ground and airborne measurements from a recent field experiment...

  16. Migration of a groundwater contaminant plume by stratabound flow in Waste Area Grouping 1 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Ketelle, R.H.; Lee, R.R.

    1992-08-01

    The discovery of radiologically contaminated groundwater in core hole CH-8 in the western portion of Waste Area Grouping (WAG) 1 at Oak Ridge National Laboratory (ORNL) prompted a detailed investigation to identify the contaminant plume. Utilizing a working hypothesis of stratabound groundwater flow and contaminant transport, investigators analyzed existing subsurface geologic data to predict the contaminant plume discharge location in first Creek and locations of contaminated groundwater seepage into storm drains. The hypothesis states that differential lithologic/fracture conditions lead to the development of preferred flow and transport pathways, of discrete vertical extent, which may not be coincident with the hydraulic gradient. Leakage out of the stratabound pathway is a minor component of the overall plume configuration

  17. Develop Documentation/Prepare Remedial Action Concept Plan for Building 24 Contamination Plume at Picatinny Arsenal

    National Research Council Canada - National Science Library

    1989-01-01

    .... TCE and other solvents were used in degreasing operations at this metal shop. Three dimensional models of ground water flow and solute transport were developed and applied to the TCE plume in the shallow aquifers around building 24...

  18. Distributional patterns of arsenic concentrations in contaminant plumes offer clues to the source of arsenic in groundwater at landfills

    Science.gov (United States)

    Harte, Philip T.

    2015-01-01

    The distributional pattern of dissolved arsenic concentrations from landfill plumes can provide clues to the source of arsenic contamination. Under simple idealized conditions, arsenic concentrations along flow paths in aquifers proximal to a landfill will decrease under anthropogenic sources but potentially increase under in situ sources. This paper presents several conceptual distributional patterns of arsenic in groundwater based on the arsenic source under idealized conditions. An example of advanced subsurface mapping of dissolved arsenic with geophysical surveys, chemical monitoring, and redox fingerprinting is presented for a landfill site in New Hampshire with a complex flow pattern. Tools to assist in the mapping of arsenic in groundwater ultimately provide information on the source of contamination. Once an understanding of the arsenic contamination is achieved, appropriate remedial strategies can then be formulated.

  19. Fate of organic contaminants in the redox zones of a landfill leachate pollution plume (Vejen, Denmark)

    DEFF Research Database (Denmark)

    Lyngkilde, John; Christensen, Thomas Højlund

    1992-01-01

    Samples from 75 sample locations in a landfill leachate pollution plume reveal a significant disappearance of specific organic compounds (SOC's) within the first 100 m of the plume. Only the herbicide Mecoprop® (MCPP) migrates further. Since sorption and dilution cannot account for the decreasing...... concentrations, degradation is considered to be the governing process. Non-volatile organic carbon shows a corresponding fate probably acting as a substrate for the microbial processes. The first 20 m of the plume are methanogenic/sulfidogenic, judged on the chemistry of the groundwater, followed...... by a significant ferrogenic zone exhibiting a substantial capacity to degrade the SOC's. The presence of intermediary products (here an oxidized camphor compound) supports the concept of degradation within the ferrogenic zone. This investigation draws the attention to the significant natural attenuation of organic...

  20. Removal of residual contaminants in petroleum-contaminated soil by Fenton-like oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Lu Mang [School of Material Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen, 333001, Jiangxi Province (China); State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China); Zhang Zhongzhi, E-mail: zzzhang1955@hotmail.com [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China); Qiao Wei; Guan Yueming; Xiao Meng; Peng Chong [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China)

    2010-07-15

    The degradation of bioremediation residues by hydrogen peroxide in petroleum-contaminated soil was investigated at circumneutral pH using a Fenton-like reagent (ferric ion chelated with EDTA). Batch tests were done on 20 g soil suspended in 60 mL aqueous solution containing hydrogen peroxide and Fe{sup 3+}-EDTA complex under constant stirring. A slurry reactor was used to treat the soil based on the optimal reactant conditions. Contaminants were characterized by Fourier transform infrared spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry. The results showed that the optimal treatment condition was: the molar ratio of hydrogen peroxide to iron = 200:1, and pH 7.0. Under the optimum condition, total dichloromethane-extractable organics were reduced from 14,800 to 2300 mg kg{sup -1} soil when the accumulative H{sub 2}O{sub 2} dosage was 2.45 mol kg{sup -1} soil during the reactor treatment. Abundance of viable cells was lower in incubated Fenton-like treated soil than in untreated soil. Oxidation of contaminants produced remarkable compositional and structural modifications. A fused ring compound, identified as C{sub 34}H{sub 38}N{sub 1}, was found to exhibit the greatest resistance to oxidation.

  1. On the significance of contaminant plume-scale and dose-response models in defining hydrogeological characterization needs

    Science.gov (United States)

    de Barros, F.; Rubin, Y.; Maxwell, R.; Bai, H.

    2007-12-01

    Defining rational and effective hydrogeological data acquisition strategies is of crucial importance since financial resources available for such efforts are always limited. Usually such strategies are developed with the goal of reducing uncertainty, but less often they are developed in the context of the impacts of uncertainty. This paper presents an approach for determining site characterization needs based on human health risk factors. The main challenge is in striking a balance between improved definition of hydrogeological, behavioral and physiological parameters. Striking this balance can provide clear guidance on setting priorities for data acquisition and for better estimating adverse health effects in humans. This paper addresses this challenge through theoretical developments and numerical testing. We will report on a wide range of factors that affect the site characterization needs including contaminant plume's dimensions, travel distances and other length scales that characterize the transport problem, as well as health risk models. We introduce a new graphical tool that allows one to investigate the relative impact of hydrogeological and physiological parameters in risk. Results show that the impact of uncertainty reduction in the risk-related parameters decreases with increasing distances from the contaminant source. Also, results indicate that human health risk becomes less sensitive to hydrogeological measurements when dealing with ergodic plumes. This indicates that under ergodic conditions, uncertainty reduction in human health risk may benefit from better understanding of the physiological component as opposed to a detailed hydrogeological characterization

  2. Assessment of attenuation processes in a chlorinated ethene plume by use of stream bed Passive Flux Meters, streambed Point Velocity Probes and contaminant mass balances

    DEFF Research Database (Denmark)

    Rønde, Vinni Kampman; McKnight, Ursula S.; Annable, Michael

    , however studies contradicting this have also been reported. Since dilution commonly reduces contaminant concentrations in streams to below quantification limits, use of mass balances along the pathway from groundwater to stream is unusual. Our study is conducted at the low-land Grindsted stream, Denmark......Chlorinated ethenes (CE) are abundant groundwater contaminants and pose risk to both groundwater and surface water bodies, as plumes can migrate through aquifers to streams. After release to the environment, CE may undergo attenuation. The hyporheic zone is believed to enhance CE attenuation......, which is impacted by a contaminant plume. CE have been observed in the stream water; hence our study site provides an unusual opportunity to study attenuation processes in a CE plume as it migrates through the groundwater at the stream bank, through the stream bed and further to the point of fully mixed...

  3. Pesticide residues and microbial contamination of water resources in the MUDA rice agroecosystem

    International Nuclear Information System (INIS)

    Cheah Uan Boh; Lum Keng Yeang

    2002-01-01

    Studies on the water resources of the Muda rice growing areas revealed evidence of pesticide residues in the agroecosystem. While the cyclodiene endosulfan was found as a ubiquitous contaminant, the occurrence of other organochlorine insecticides was sporadic. The presence of 2,4-D, paraquat and molinate residues was also evident but the occurrence of these herbicides was seasonal. Residue levels of molinate were generally higher than those from the other herbicides. The problem of thiobencarb and carbofuran residues was not encountered. Analyses for microbial contamination revealed that the water resources were unfit for drinking; coliform counts were higher during certain periods of the year than others. (Author)

  4. Quantitative analysis of residual protein contamination of podiatry instruments reprocessed through local and central decontamination units.

    Science.gov (United States)

    Smith, Gordon Wg; Goldie, Frank; Long, Steven; Lappin, David F; Ramage, Gordon; Smith, Andrew J

    2011-01-10

    The cleaning stage of the instrument decontamination process has come under increased scrutiny due to the increasing complexity of surgical instruments and the adverse affects of residual protein contamination on surgical instruments. Instruments used in the podiatry field have a complex surface topography and are exposed to a wide range of biological contamination. Currently, podiatry instruments are reprocessed locally within surgeries while national strategies are favouring a move toward reprocessing in central facilities. The aim of this study was to determine the efficacy of local and central reprocessing on podiatry instruments by measuring residual protein contamination of instruments reprocessed by both methods. The residual protein of 189 instruments reprocessed centrally and 189 instruments reprocessed locally was determined using a fluorescent assay based on the reaction of proteins with o-phthaldialdehyde/sodium 2-mercaptoethanesulfonate. Residual protein was detected on 72% (n = 136) of instruments reprocessed centrally and 90% (n = 170) of instruments reprocessed locally. Significantly less protein (p podiatry instruments when protein contamination is considered, though no significant difference was found in residual protein between local decontamination unit and central decontamination unit processes for Blacks files. Further research is needed to undertake qualitative identification of protein contamination to identify any cross contamination risks and a standard for acceptable residual protein contamination applicable to different instruments and specialities should be considered as a matter of urgency.

  5. Quantitative analysis of residual protein contamination of podiatry instruments reprocessed through local and central decontamination units

    Directory of Open Access Journals (Sweden)

    Ramage Gordon

    2011-01-01

    Full Text Available Abstract Background The cleaning stage of the instrument decontamination process has come under increased scrutiny due to the increasing complexity of surgical instruments and the adverse affects of residual protein contamination on surgical instruments. Instruments used in the podiatry field have a complex surface topography and are exposed to a wide range of biological contamination. Currently, podiatry instruments are reprocessed locally within surgeries while national strategies are favouring a move toward reprocessing in central facilities. The aim of this study was to determine the efficacy of local and central reprocessing on podiatry instruments by measuring residual protein contamination of instruments reprocessed by both methods. Methods The residual protein of 189 instruments reprocessed centrally and 189 instruments reprocessed locally was determined using a fluorescent assay based on the reaction of proteins with o-phthaldialdehyde/sodium 2-mercaptoethanesulfonate. Results Residual protein was detected on 72% (n = 136 of instruments reprocessed centrally and 90% (n = 170 of instruments reprocessed locally. Significantly less protein (p Conclusions Overall, the results show the superiority of central reprocessing for complex podiatry instruments when protein contamination is considered, though no significant difference was found in residual protein between local decontamination unit and central decontamination unit processes for Blacks files. Further research is needed to undertake qualitative identification of protein contamination to identify any cross contamination risks and a standard for acceptable residual protein contamination applicable to different instruments and specialities should be considered as a matter of urgency.

  6. Evolution of radioactive dose rates in fresh sediment deposits along coastal rivers draining Fukushima contamination plume.

    Science.gov (United States)

    Evrard, Olivier; Chartin, Caroline; Onda, Yuichi; Patin, Jeremy; Lepage, Hugo; Lefèvre, Irène; Ayrault, Sophie; Ottlé, Catherine; Bonté, Philippe

    2013-10-29

    Measurement of radioactive dose rates in fine sediment that has recently deposited on channel bed-sand provides a solution to address the lack of continuous river monitoring in Fukushima Prefecture after Fukushima Dai-ichi nuclear power plant (FDNPP) accident. We show that coastal rivers of Eastern Fukushima Prefecture were rapidly supplied with sediment contaminated by radionuclides originating from inland mountain ranges, and that this contaminated material was partly exported by typhoons to the coastal plains as soon as by November 2011. This export was amplified during snowmelt and typhoons in 2012. In 2013, contamination levels measured in sediment found in the upper parts of the catchments were almost systematically lower than the ones measured in nearby soils, whereas their contamination was higher in the coastal plains. We thereby suggest that storage of contaminated sediment in reservoirs and in coastal sections of the river channels now represents the most crucial issue.

  7. Assessing chlorinated ethene degradation in a large scale contaminant plume by dual carbon–chlorine isotope analysis and quantitative PCR

    DEFF Research Database (Denmark)

    Hunkeler, D.; Abe, Y.; Broholm, Mette Martina

    2011-01-01

    The fate of chlorinated ethenes in a large contaminant plume originating from a tetrachloroethene (PCE) source in a sandy aquifer in Denmark was investigated using novel methods including compound-specific carbon and chlorine isotope analysis and quantitative real-time polymerase chain reaction (q...... reduction by pyrite as indicated by the formation of cDCE and stable carbon isotope data. TCE and cDCE showed carbon isotope trends typical for reductive dechlorination with an initial depletion of 13C in the daughter products followed by an enrichment of 13C as degradation proceeded. At 1000 m downgradient......DCE. The significant enrichment of 13C in VC indicates that VC was transformed further, although the mechanismcould not be determined. The transformation of cDCEwas the rate limiting step as no accumulation of VC occurred. In summary, the study demonstrates that carbon–chlorine isotope analysis and qPCR combinedwith...

  8. Coupling of Realistic Rate Estimates with Genomics for Assessing Contaminant Attenuation and Long-Term Plume Containment

    Energy Technology Data Exchange (ETDEWEB)

    Colwell, F. S.; Crawford, R. L.; Sorenson, K.

    2005-09-01

    Acceptance of monitored natural attenuation (MNA) as a preferred treatment technology saves significant site restoration costs for DOE. However, in order to be accepted MNA requires direct evidence of which processes are responsible for the contaminant loss and also the rates of the contaminant loss. Our proposal aims to: 1) provide evidence for one example of MNA, namely the disappearance of the dissolved trichloroethylene (TCE) from the Snake River Plain aquifer (SRPA) at the Idaho National Laboratory’s Test Area North (TAN) site, 2) determine the rates at which aquifer microbes can co-metabolize TCE, and 3) determine whether there are other examples of natural attenuation of chlorinated solvents occurring at DOE sites. To this end, our research has several objectives. First, we have conducted studies to characterize the microbial processes that are likely responsible for the co-metabolic destruction of TCE in the aquifer at TAN (University of Idaho and INL). Second, we are investigating realistic rates of TCE co-metabolism at the low catabolic activities typical of microorganisms existing under aquifer conditions (INL). Using the co-metabolism rate parameters derived in low-growth bioreactors, we will complete the models that predict the time until background levels of TCE are attained in the aquifer at TAN and validate the long-term stewardship of this plume. Coupled with the research on low catabolic activities of co-metabolic microbes we are determining the patterns of functional gene expression by these cells, patterns that may be used to diagnose the co-metabolic activity in the SRPA or other aquifers. Third, we have systematically considered the aquifer contaminants at different locations in plumes at other DOE sites in order to determine whether MNA is a broadly applicable remediation strategy for chlorinated hydrocarbons (North Wind Inc.). Realistic terms for co-metabolism of TCE will provide marked improvements in DOE’s ability to predict and

  9. Evolution of radioactive dose rates in fresh sediment deposits along coastal rivers draining Fukushima contamination plume

    OpenAIRE

    Evrard, Olivier; Chartin, Caroline; Onda, Yuichi; Patin, Jeremy; Lepage, Hugo; Lef?vre, Ir?ne; Ayrault, Sophie; Ottl?, Catherine; Bont?, Philippe

    2013-01-01

    Measurement of radioactive dose rates in fine sediment that has recently deposited on channel bed-sand provides a solution to address the lack of continuous river monitoring in Fukushima Prefecture after Fukushima Dai-ichi nuclear power plant (FDNPP) accident. We show that coastal rivers of Eastern Fukushima Prefecture were rapidly supplied with sediment contaminated by radionuclides originating from inland mountain ranges, and that this contaminated material was partly exported by typhoons t...

  10. Methodology for determining acceptable residual radioactive contamination levels at decommissioned nuclear facilities/sites

    International Nuclear Information System (INIS)

    Watson, E.C.; Kennedy, W.E. Jr.; Hoenes, G.R.; Waite, D.A.

    1979-01-01

    The ultimate disposition of decommissioned nuclear facilities and their surrrounding sites depends upon the degree and type of residual contamination. Examination of existing guidelines and regulations has led to the conclusion that there is a need for a general method to derive residual radioactive contamination levels that are acceptable for public use of any decommissioned nuclear facility or site. This paper describes a methodology for determining acceptable residual radioactive contamination levels based on the concept of limiting the annual dose to members of the public. It is not the purpose of this paper to recommend or even propose dose limits for the exposure of the public to residual radioactive contamination left at decommissioned nuclear facilities or sites. Unrestricted release of facilities and/or land is based on the premise that the potential annual dose to any member of the public using this property from all possible exposure pathways will not exceed appropriate limits as may be defined by Federal regulatory agencies. For decommissioned land areas, consideration should be given to people living directly on previously contaminated areas, growing crops, grazing food animals and using well water. Mixtures of radionuclides in the residual contamination representative of fuel reprocessing plants, light water reactors and their respective sites are presented. These mixtures are then used to demonstrate the methodology. Example acceptable residual radioactive contamination levels, based on an assumed maximum annual dose of one millirem, are calculated for several selected times following shutdown of a facility. It is concluded that the methodology presented in this paper results in defensible acceptable residual contamination levels that are directly relatable to risk assessment with the proviso that an acceptable limit to the maximum annual dose will be established. (author)

  11. Food toxicology. Residues and contaminants: Risks and consumer protection; Lebensmitteltoxikologie. Rueckstaende und Kontaminanten: Risiken und Verbraucherschutz

    Energy Technology Data Exchange (ETDEWEB)

    Nau, H. [Tieraerztliche Hochschule Hannover, ZA Lebensmitteltoxikologie (Germany); Steinberg, P. [Potsdam Univ., Inst. fuer Ernaehrungswissenschaft (Germany); Kietzmann, M. (eds.) [Tieraerztliche Hochschule Hannover, Inst. fuer Pharmakologie, Toxikologie/Pharmazie (Germany)

    2003-07-01

    In a detailed introduction, the basic methods of risk assessment for potentially toxic food constituents are presented as well as the analytical methods applied for measuring even very small concentrations of contaminants. The main classes of substances relevant in foods ar represented, i.e. animal drugs, fungicides and herbicides, natural toxins, contaminants, prions from BSE-infested animals and residues of 'new' proteins and 'new' DNA from genetically modified foods. New legislation in Germany and Europe is presented including the National Residue Monitoring Plant which is to enable annual monitoring of residue concentrations in foods derived from animals. (orig.)

  12. Innovative Use of Cr(VI) Plume Depictions and Pump-and-Treat Capture Analysis to Estimate Risks of Contaminant Discharge to Surface Water at Hanford Reactor Areas

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Chuck W.; Hanson, James P.; Ivarson, Kristine A.; Tonkin, M.

    2015-01-14

    The Hanford Site nuclear reactor operations required large quantities of high-quality cooling water, which was treated with chemicals including sodium dichromate dihydrate for corrosion control. Cooling water leakage, as well as intentional discharge of cooling water to ground during upset conditions, produced extensive groundwater recharge mounds consisting largely of contaminated cooling water and resulted in wide distribution of hexavalent chromium (Cr[VI]) contamination in the unconfined aquifer. The 2013 Cr(VI) groundwater plumes in the 100 Areas cover approximately 6 km2 (1500 acres), primarily in the 100-HR-3 and 100-KR-4 groundwater operable units (OUs). The Columbia River is a groundwater discharge boundary; where the plumes are adjacent to the Columbia River there remains a potential to discharge Cr(VI) to the river at concentrations above water quality criteria. The pump-and-treat systems along the River Corridor are operating with two main goals: 1) protection of the Columbia River, and 2) recovery of contaminant mass. An evaluation of the effectiveness of the pump-and-treat systems was needed to determine if the Columbia River was protected from contamination, and also to determine where additional system modifications may be needed. In response to this need, a technique for assessing the river protection was developed which takes into consideration seasonal migration of the plume and hydraulic performance of the operating well fields. Groundwater contaminant plume maps are generated across the Hanford Site on an annual basis. The assessment technique overlays the annual plume and the capture efficiency maps for the various pump and treat systems. The river protection analysis technique was prepared for use at the Hanford site and is described in detail in M.J. Tonkin, 2013. Interpolated capture frequency maps, based on mapping dynamic water level observed in observation wells and derived water levels in the vicinity of extraction and injection wells

  13. Hanford Site Tank 241-C-108 Residual Waste Contaminant Release Models and Supporting Data

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J.; Krupka, Kenneth M.; Geiszler, Keith N.; Arey, Bruce W.; Schaef, Herbert T.

    2010-06-18

    This report presents the results of laboratory characterization, testing, and analysis for a composite sample (designated 20578) of residual waste collected from single-shell tank C-108 during the waste retrieval process after modified sluicing. These studies were completed to characterize concentration and form of contaminant of interest in the residual waste; assess the leachability of contaminants from the solids; and develop release models for contaminants of interest. Because modified sluicing did not achieve 99% removal of the waste, it is expected that additional retrieval processing will take place. As a result, the sample analyzed here is not expected to represent final retrieval sample.

  14. Coupling of Realistic Rate Estimates with Genomics for Assessing Contaminant Attenuation and Long-Term Plume Containment

    Energy Technology Data Exchange (ETDEWEB)

    Colwell, F. S.; Crawford, R. L.; Sorenson, K.

    2005-06-01

    Dissolved dense nonaqueous-phase liquid plumes are persistent, widespread problems in the DOE complex. At the Idaho National Engineering and Environmental Laboratory, dissolved trichloroethylene (TCE) is disappearing from the Snake River Plain aquifer (SRPA) by natural attenuation, a finding that saves significant site restoration costs. Acceptance of monitored natural attenuation as a preferred treatment technology requires direct evidence of the processes and rates of the degradation. Our proposal aims to provide that evidence for one such site by testing two hypotheses. First, we believe that realistic values for in situ rates of TCE cometabolism can be obtained by sustaining the putative microorganisms at the low catabolic activities consistent with aquifer conditions. Second, the patterns of functional gene expression evident in these communities under starvation conditions while carrying out TCE cometabolism can be used to diagnose the cometabolic activity in the aquifer itself. Using the cometabolism rate parameters derived in low-growth bioreactors, we will complete the models that predict the time until background levels of TCE are attained at this location and validate the long-term stewardship of this plume. Realistic terms for cometabolism of TCE will provide marked improvements in DOE's ability to predict and monitor natural attenuation of chlorinated organics at other sites, increase the acceptability of this solution, and provide significant economic and health benefits through this noninvasive remediation strategy. Finally, this project aims to derive valuable genomic information about the functional attributes of subsurface microbial communities upon which DOE must depend to resolve some of its most difficult contamination issues.

  15. Activated carbon immobilizes residual polychlorinated biphenyls in weathered contaminated soil.

    Science.gov (United States)

    Langlois, Valérie S; Rutter, Allison; Zeeb, Barbara A

    2011-01-01

    Activated carbon (AC) has recently been shown to be effective in sequestering persistent organic pollutants (POPs) from aquatic sediments. Most studies have demonstrated significant reductions of POP concentrations in water and in aquatic organisms; however, limited data exist on the possibility of using AC to immobilize remaining POPs at terrestrial contaminated sites. Under greenhouse conditions, pumpkin ssp cv. Howden) were grown, and red wiggler worms () were exposed to an industrial contaminated soil containing a mixture of polychlorinated biphenyls (PCBs), i.e., Aroclors 1254 and 1260) treated with one of four concentrations of AC (0.2, 0.8, 3.1, and 12.5%) for 2 mo. The addition of AC to contaminated soils virtually eliminated the bioavailability of PCBs to the plant and invertebrate species. There were reductions in PCB concentrations of more than 67% in ssp and 95% in . These data suggest that AC could be included as part of comprehensive site closure strategy at PCB-contaminated sites. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. Modelling of contaminant migration in acidic groundwater plumes at uranium tailings impoundments: ADNEUT3

    International Nuclear Information System (INIS)

    Cherry, J.A.; Morin, K.A.; Dubrovsky, N.M.

    1984-06-01

    This report describes the creation and application of ADNEUT3, the latest addition to the ADNEUT (Acid-Drainage NEUTralization) family of computer programs for simulating acid-drainage transport and neutralization. The creation of ADNEUT3 involved the expansion of ADNEUT1 to allow variable input conditions such as changing input solution with time, variable initial amounts of minerals through the simulated streamtube, variable velocities through the streamtube, and variable solubilities for relevant minerals dependent on aqueous chemical composition. Concepts for simulating acid-drainage neutralization are reviewed and ADNEUT3 is then applied to a field-study site of acidic contaminant migration from the Nordic Main uranium-tailings impoundment near Elliot Lake, Ontario. A sensitivity study is first implemented to calibrate ADNEUT3 to the results of the 1979 to 1983 field studies. Then ADNEUT3 is used to define probable past conditions at the site which are not reliably known. In particular, ADNEUT3 is used to help identify: 1) the approximate year when acidic seepage began leaving the tailings impoundment (1966-1967), 2) the past chemical composition of the seepage (somewhat more acidic for a short period of time), and 3) the location of the source area within the tailings for the acidic seepage (near the impoundment dam, close to the field site). Finally, ADNEUT3 is used to predict future contaminant migration. Results indicate that hundreds of years are required under present conditions for the most acidic water with associated high levels of contaminants to migrate about 100 m from the tailings impoundment. The cause of this slow movement is the significant neutralization capacity of the aquifer. If acid production within the tailings decreases in the future, migration rates of contaminants will also decrease

  17. Radioactive Plumes Monitoring Simulator

    International Nuclear Information System (INIS)

    Kapelushnik, I.; Sheinfeld, M.; Avida, R.; Kadmon, Y.; Ellenbogen, M.; Tirosh, D.

    1999-01-01

    The Airborne Radiation Monitoring System (ARMS) monitors air or ground radioactive contamination. The contamination source can be a radioactive plume or an area contaminated with radionuclides. The system is based on two major parts, an airborne unit carried by a helicopter and a ground station carried by a truck. The system enables real time measurement and analysis of radioactive plumes as well as post flight processing. The Radioactive Plumes Monitoring Simulator purpose is to create a virtual space where the trained operators experience full radiation field conditions, without real radiation hazard. The ARMS is based on a flying platform and hence the simulator allows a significant reduction of flight time costs

  18. Remediation of deltamethrin contaminated cotton fields: residual and adsorption assessment

    Directory of Open Access Journals (Sweden)

    Rafique Uzaira

    2016-01-01

    Full Text Available Pakistan occupies a significant global position in the growing of high quality cotton. The extensive application of pesticides on agricultural products leads to environmental risk due to toxic residues in air, water and soil. This study examined the chemodynamic effect of Deltamethrin on cotton fields. Samples were collected from the cotton fields of D.G. Khan, Pakistan and analyzed for heavy metal speciation patterns. Batch experiments were administered in order to study the adsorption of Deltamethrin in cotton fields. The effect of different factors including pH, adsorbate dose, and adsorbent mass on adsorption were studied. It was observed that in general, adsorption increased with increases in the mass of adsorbate, although the trends were irregular. Residual fractions of deltamethrin in the soil and water of cotton fields were analyzed to assess concentrations of xenobiotics bound to soil particles. Results indicated that such residues are significantly higher in soil samples due to high Koc in comparison to water, indicating the former is an efficient degradation agent. Results from the batch experiment resulted in 95% removal with alkaline pH and an adsorbent-adsorbate ratio of 250:1. These results may be used to environment friendly resource management policies.

  19. Intrinsic Anaerobic Bioremediation of Hydrocarbons in Contaminated Subsurface Plumes and Marine Sediments

    Science.gov (United States)

    Nanny, M. A.; Nanny, M. A.; Suflita, J. M.; Suflita, J. M.; Davidova, I.; Kropp, K.; Caldwell, M.; Philp, R.; Gieg, L.; Rios-Hernandez, L. A.

    2001-05-01

    In recent years, several classes of petroleum hydrocarbons contaminating subsurface and marine environments have been found susceptible to anaerobic biodegradation using novel mechanisms entirely distinct from aerobic metabolic pathways. For example, the anaerobic decay of toluene can be initiated by the addition of the aryl methyl group to the double bond of fumarate, resulting in a benzylsuccinic acid metabolite. Our work has shown that an analogous mechanism also occurs with ethylbenzene and the xylene isomers, yielding 3-phenyl-1,2-butane dicarboxylic acid and methylbenzylsuccinic acid, respectively. Moreover, these metabolites have been detected in contaminated environments. Most recently, we have identified metabolites resulting from the initial attack of H26- or D26-n-dodecane during degradation by a sulfate-reducing bacterial culture. Using GC-MS, these metabolites were identified as fatty acids that result from C-H or C-D addition across the double bond of fumarate to give dodecylsuccinic acids in which all 26 protons or deuteriums of the parent alkane were retained. Further, when this enrichment culture was challenged with hexane or decane, hexylsuccinic acid or decylsuccinic acid were identified as resulting metabolites. Similarly, the study of an ethylcyclopentane-degrading sulfate-reducing enrichment produced a metabolite, which is consistent with the addition of fumarate to the parent substrate. These novel anaerobic addition products are characterized by similar, distinctive mass spectral (MS) features (ions specific to the succinic acid portion of the molecule) that can potentially be used to probe contaminated environments for evidence of intrinsic remediation of hydrocarbons. Indeed, analyses of water extracts from two gas condensate-contaminated sites resulted in the tentative detection of alkyl- and cycloalkylsuccinic acids ranging from C3 to C9, including ethylcyclopentyl-succinic acid. In water extracts collected from an area underlying a

  20. Using ASCEM Modeling and Visualization to Inform Stakeholders of Contaminant Plume Evolution and Remediation Efficacy at F-Basin Savannah River, SC – 15156

    Energy Technology Data Exchange (ETDEWEB)

    Flach, G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wainwright, H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Molins, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Davis, J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Arora, B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faybishenko, B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Krishnan, H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hubbard, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Flach, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Denham, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Eddy-Dilek, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Moulton, D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lipnikov, K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gable, C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Miller, T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Freshley, M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-01-28

    Communication with stakeholders, regulatory agencies, and the public is an essential part of implementing different remediation and monitoring activities, and developing site closure strategies at contaminated sites. Modeling of contaminant plume evolution plays a critical role in estimating the benefit, cost, and risk of particular options. At the same time, effective visualization of monitoring data and modeling results are particularly important for conveying the significance of the results and observations. In this paper, we present the results of the Advanced Simulation Capability for Environmental Management (ASCEM) project, including the discussion of the capabilities of newly developed ASCEM software package, along with its application to the F-Area Seepage Basins located in the U.S. Department of Energy Savannah River Site (SRS). ASCEM software includes state-of-the-art numerical methods for simulating complex flow and reactive transport, as well as various toolsets such as a graphical user interface (GUI), visualization, data management, uncertainty quantification, and parameter estimation. Using this software, we have developed an advanced visualization of tritium plume migration coupled with a data management system, and simulated a three-dimensional model of flow and plume evolution on a high-performance computing platform. We evaluated the effect of engineered flow barriers on a nonreactive tritium plume, through advanced plume visualization and modeling of tritium plume migration. In addition, we developed a geochemical reaction network to describe complex geochemical processes at the site, and evaluated the impact of coupled hydrological and geochemical heterogeneity. These results are expected to support SRS’s monitoring activities and operational decisions.

  1. The Oak Ridge Field Research Center : Advancing Scientific Understanding of the Transportation, Fate, and Remediation of Subsurface Contamination Sources and Plumes

    International Nuclear Information System (INIS)

    David Watson

    2005-01-01

    Historical research, development, and testing of nuclear materials across this country resulted in subsurface contamination that has been identified at over 7,000 discrete sites across the U.S. Department of Energy (DOE) complex. With the end of the Cold War threat, DOE has shifted its emphasis to remediation, decommissioning, and decontamination of the immense volumes of contaminated groundwater, sediments, and structures at its sites. DOE currently is responsible for remediating 1.7 trillion gallons of contaminated groundwater, an amount equal to approximately four times the daily U.S. water consumption, and 40 million cubic meters of contaminated soil, enough to fill approximately 17 professional sports stadiums.* DOE also sponsors research intended to improve or develop remediation technologies, especially for difficult, currently intractable contaminants or conditions. The Oak Ridge FRC is representative of some difficult sites, contaminants, and conditions. Buried wastes in contact with a shallow water table have created huge reservoirs of contamination. Rainfall patterns affect the water table level seasonally and over time. Further, the hydrogeology of the area, with its fractures and karst geology, affects the movement of contaminant plumes. Plumes have migrated long distances and to surface discharge points through ill-defined preferred flowpaths created by the fractures and karst conditions. From the standpoint of technical effectiveness, remediation options are limited, especially for contaminated groundwater. Moreover, current remediation practices for the source areas, such as capping, can affect coupled processes that, in turn, may affect the movement of subsurface contaminants in unknown ways. Research conducted at the FRC or with FRC samples therefore promotes understanding of the processes that influence the transport and fate of subsurface contaminants, the effectiveness and long-term consequences of extant remediation options, and the

  2. Contaminant interferences with SIMS analyses of microparticle impactor residues on LDEF surfaces

    International Nuclear Information System (INIS)

    Simon, C.G.; Batchelor, D.; Griffis, D.P.; Hunter, J.L.; Misra, V.; Ricks, D.A.; Wortman, J.J.

    1992-01-01

    Elemental analyses of impactor residues on high purity surface exposed to the low earth orbit (LEO) environment for 5.8 years on Long Duration Exposure Facility (LDEF) has revealed several probable sources for microparticles at this altitude, including natural micrometeorites and manmade debris ranging from paint pigments to bits of stainless steel. A myriad of contamination interferences were identified and their effects on impactor debris identification mitigated during the course of this study. These interferences included pre-, post-, and in-flight deposited particulate surface contaminants, as well as indigenous heterogeneous material contaminants. Non-flight contaminants traced to human origins, including spittle and skin oils, contributed significant levels of alkali-rich carbonaceous interferences. A ubiquitous layer of in-flight deposited silicaceous contamination varied in thickness with location on LDEF and proximity to active electrical fields. In-flight deposited (low velocity) contaminants included urine droplets and bits of metal film from eroded thermal blankets

  3. Predictive geochemical modeling of contaminant concentrations in laboratory columns and in plumes migrating from uranium mill tailings waste impoundments

    International Nuclear Information System (INIS)

    Peterson, S.R.; Martin, W.J.; Serne, R.J.

    1986-04-01

    A computer-based conceptual chemical model was applied to predict contaminant concentrations in plumes migrating from a uranium mill tailings waste impoundment. The solids chosen for inclusion in the conceptual model were selected based on reviews of the literature, on ion speciation/solubility calculations performed on the column effluent solutions and on mineralogical characterization of the contacted and uncontacted sediments. The mechanism of adsorption included in the conceptual chemical model was chosen based on results from semiselective extraction experiments and from mineralogical characterization procedures performed on the sediments. This conceptual chemical model was further developed and partially validated in laboratory experiments where assorted acidic uranium mill tailings solutions percolated through various sediments. This document contains the results of a partial field and laboratory validation (i.e., test of coherence) of this chemical model. Macro constituents (e.g., Ca, SO 4 , Al, Fe, and Mn) of the tailings solution were predicted closely by considering their concentrations to be controlled by the precipitation/dissolution of solid phases. Trace elements, however, were generally predicted to be undersaturated with respect to plausible solid phase controls. The concentration of several of the trace elements were closely predicted by considering their concentrations to be controlled by adsorption onto the amorphous iron oxyhydroxides that precipitated

  4. Coupling of Realistic Rate Estimates with Genomics for Assessing Contaminant Attenuation and Long-Term Plume Containment

    Energy Technology Data Exchange (ETDEWEB)

    Colwell, F.S.; Crawford, R.L.; Sorenson, K.

    2005-09-01

    Acceptance of monitored natural attenuation (MNA) as a preferred treatment technology saves significant site restoration costs for DOE. However, in order to be accepted MNA requires direct evidence of which processes are responsible for the contaminant loss and also the rates of the contaminant loss. Our proposal aims to: 1) provide evidence for one example of MNA, namely the disappearance of the dissolved trichloroethylene (TCE) from the Snake River Plain aquifer (SRPA) at the Idaho National Laboratory’s Test Area North (TAN) site, 2) determine the rates at which aquifer microbes can co-metabolize TCE, and 3) determine whether there are other examples of natural attenuation of chlorinated solvents occurring at DOE sites. To this end, our research has several objectives. First, we have conducted studies to characterize the microbial processes that are likely responsible for the co-metabolic destruction of TCE in the aquifer at TAN (University of Idaho and INL). Second, we are investigating realistic rates of TCE co-metabolism at the low catabolic activities typical of microorganisms existing under aquifer conditions (INL). Using the co-metabolism rate parameters derived in low-growth bioreactors, we will complete the models that predict the time until background levels of TCE are attained in the aquifer at TAN and validate the long-term stewardship of this plume. Coupled with the research on low catabolic activities of co-metabolic microbes we are determining the patterns of functional gene expression by these cells, patterns that may be used to diagnose the co-metabolic activity in the SRPA or other aquifers.

  5. Plant residues--a low cost, effective bioremediation treatment for petrogenic hydrocarbon-contaminated soil.

    Science.gov (United States)

    Shahsavari, Esmaeil; Adetutu, Eric M; Anderson, Peter A; Ball, Andrew S

    2013-01-15

    Petrogenic hydrocarbons represent the most commonly reported environmental contaminant in industrialised countries. In terms of remediating petrogenic contaminated hydrocarbons, finding sustainable non-invasive technologies represents an important goal. In this study, the effect of 4 types of plant residues on the bioremediation of aliphatic hydrocarbons was investigated in a 90 day greenhouse experiment. The results showed that contaminated soil amended with different plant residues led to statistically significant increases in the utilisation rate of Total Petroleum Hydrocarbon (TPH) relative to control values. The maximum TPH reduction (up to 83% or 6800 mg kg(-1)) occurred in soil mixed with pea straw, compared to a TPH reduction of 57% (4633 mg kg(-1)) in control soil. A positive correlation (0.75) between TPH reduction rate and the population of hydrocarbon-utilising microorganisms was observed; a weaker correlation (0.68) was seen between TPH degradation and bacterial population, confirming that adding plant materials significantly enhanced both hydrocarbonoclastic and general microbial soil activities. Microbial community analysis using Denaturing Gradient Gel Electrophoresis (DGGE) showed that amending the contaminated soil with plant residues (e.g., pea straw) caused changes in the soil microbial structure, as observed using the Shannon diversity index; the diversity index increased in amended treatments, suggesting that microorganisms present on the dead biomass may become important members of the microbial community. In terms of specific hydrocarbonoclastic activity, the number of alkB gene copies in the soil microbial community increased about 300-fold when plant residues were added to contaminated soil. This study has shown that plant residues stimulate TPH degradation in contaminated soil through stimulation and perhaps addition to the pool of hydrocarbon-utilising microorganisms, resulting in a changed microbial structure and increased alkB gene

  6. A hybrid method for the simulation of radionuclide contaminant plumes in heterogeneous, unsaturated formations

    International Nuclear Information System (INIS)

    Aquino, J.; Pereira, T.J.; Souto, H.P. Amaral; Francisco, A.S.

    2009-01-01

    The decision concerning the location of sites for nuclear waste repositories in the subsurface depends upon the long-term containment capabilities of hydrogeological environments. The numerical simulation of the multiphase flow and contaminant transport that take place in this problem is an important tool to help engineers and scientists in selecting appropriate sites. In this paper, we employ a hybrid strategy that combines an Eulerian approximation scheme for the underlying two-phase flow problem with a locally conservative Lagrangian method to approximate the transport of radionuclide. This Lagrangian scheme is computationally efficient and virtually free of numerical diffusion. In order to face unsaturated and heterogeneous problems, four extensions in the Lagrangian scheme are implemented. To show the effectiveness of the improved version we perform a grid refinement study. (author)

  7. Permeable sorptive walls for treatment of hydrophobic organic contaminant plumes in groundwater

    International Nuclear Information System (INIS)

    Grathwohl, P.; Peschik, G.

    1997-01-01

    Highly hydrophobic contaminants are easily adsorbed from aqueous solutions. Since for many of these compounds sorption increases with increasing organic carbon content natural materials such as bituminous shales and coals may be used in permeable sorptive walls. This, however, only applies if sorption is at equilibrium, which may not always be the case in groundwater treatment using a funnel-and-gate system. In contrast to the natural solids, granular activated carbons (GACs) have very high sorption capacities and reasonably fast sorption kinetics. The laboratory results show that application of GACs (e.g. F100) is economically feasible for in situ removal of polycyclic aromatic hydrocarbons (PAH) from groundwater at a former manufactured gas plant site (MGP). For less sorbing compounds (such as benzene, toluene, xylenes) a combination of adsorption and biodegradation is necessary (i.e. sorptive + reactive treatment)

  8. Monitoring pesticides residues and contaminants for some leafy vegetables at the market level

    International Nuclear Information System (INIS)

    Ibrahim, A. B. H.

    2004-03-01

    Pesticide residues and contaminants in selected leafy vegetables, namely (lettuce, garden rocket and salad onion) were monitored at market level in Riyadh City in Saudi Arabia, during the period june to july 2001. Fifteen samples of vegetables from the City vegetable market of Riyadh were collected and subjected to multi-pesticide residue detection and analysis by gas chromatography with mass spectrometer and electron capture detectors (GC/MS,ECD). Results of sample extracts analysis showed that the two vegetables of: garden rocket and salad onion contain pesticide residues and contaminants which have no Maximum Residue Limits (MRL) prescribed by Codex Alimentarius Commission (CAC) collaborate with World Health and Food and Agriculture Organizations (WHO/FAO). Whereas lettuce vegetable was found free of any identified pesticide residues or contaminants. Garden rocket was shown to contain dibutyl phthalate (0.04 ppm)-steryl chloride (0.02 ppm) tridecane (0.06 ppm)-hexadecane (0.07 ppm)-BIS (ethylhexyl) phthalate (0.006 ppm) and pyridinium, 1-hexyl chloride (0.01 ppm). The salad onion was found to contain 9-octadecanamide (0.13 ppm)-tridecane (0.15 ppm) and tetradecane (0.16 ppm). There are no established MRL s for these pesticides and contaminants detected in garden rocket and salad onion, although when impacts on human health were reviewed some of them were found probably hazardous. (Author)

  9. Assessment of attenuation processes in a chlorinated ethene plume by use of stream bed Passive Flux Meters, streambed Point Velocity Probes and contaminant mass balances

    Science.gov (United States)

    Rønde, V.; McKnight, U. S.; Annable, M. D.; Devlin, J. F.; Cremeans, M.; Sonne, A. T.; Bjerg, P. L.

    2017-12-01

    Chlorinated ethenes (CE) are abundant groundwater contaminants and pose risk to both groundwater and surface water bodies, as plumes can migrate through aquifers to streams. After release to the environment, CE may undergo attenuation. The hyporheic zone is believed to enhance CE attenuation, however studies contradicting this have also been reported. Since dilution commonly reduces contaminant concentrations in streams to below quantification limits, use of mass balances along the pathway from groundwater to stream is unusual. Our study is conducted at the low-land Grindsted stream, Denmark, which is impacted by a contaminant plume. CE have been observed in the stream water; hence our study site provides an unusual opportunity to study attenuation processes in a CE plume as it migrates through the groundwater at the stream bank, through the stream bed and further to the point of fully mixed conditions in the stream. The study undertook the determination of redox conditions and CE distribution from bank to stream; streambed contaminant flux estimation using streambed Passive Flux Meters (sPFM); and quantification of streambed water fluxes using temperature profiling and streambed Point Velocity Probes (SBPVP). The advantage of the sPFM is that it directly measures the contaminant flux without the need for water samples, while the advantage of the SBPVP is its ability to measure the vertical seepage velocity without the need for additional geological parameters. Finally, a mass balance assessment along the plume pathway was conducted to account for any losses or accumulations. The results show consistencies in spatial patterns between redox conditions and extent of dechlorination; between contaminant fluxes from sPFM and concentrations from water samples; and between seepage velocities from SBPVP and temperature-based water fluxes. Mass balances and parent-metabolite compound ratios indicate limited degradation between the bank and the point of fully mixed stream

  10. Geotechnical behavior of a tropical residual soil contaminated with gasoline

    Directory of Open Access Journals (Sweden)

    Óscar Echeverri-Ramírez

    2015-01-01

    Full Text Available La infraestructura para transporte de hidrocarburos ha crecido de manera importante debido a la necesidad de abastecer la mayo r cantidad de poblaciones; sin embargo por pro blemas en las redes de sumin istro, se presentan derrames accidentales que contaminan los su elos bajo los cuales se apoyan estas estructuras. Los suelos contaminados , en este caso particular con gasolina, son la motivación del p resente artículo, el cual pretende analizar los cambios que ocurren en un suelo d e origen residual tropical al ser contaminado con éste; mediant e pruebas de laboratorio específicos para caracterizar este tipo de suelos (Clasificación Miniatura Compactado Tropical, Succión, Pinhole Test, Índice de Colapso, Difracción de rayos “X”, Microscopía Electrónica de Barrido, determinación de pH y de ensayos tradicionales (hume dad natural, gravedad específica, granulometría, límites de Atterbe rg, corte directo, etc, tanto con muestras en estado natural c omo contaminadas que permitan percibir las posibles variaciones en las características mecánicas del material.

  11. Blast furnace residues for arsenic removal from mining-contaminated groundwater.

    Science.gov (United States)

    Carrillo-Pedroza, Fco Raúl; Soria-Aguilar, Ma de Jesús; Martínez-Luevanos, Antonia; Narvaez-García, Víctor

    2014-01-01

    In this work, blast furnace (BF) residues were well characterized and then evaluated as an adsorbent material for arsenic removal from a mining-contaminated groundwater. The adsorption process was analysed using the theories of Freundlich and Langmuir. BF residues were found to be an effective sorbent for As (V) ions. The modelling of adsorption isotherms by empirical models shows that arsenate adsorption is fitted by the Langmuir model, suggesting a monolayer adsorption of arsenic onto adsorbents. Arsenate adsorption onto BF residue is explained by the charge density surface affinity and by the formation of Fe (II) and Fe (III) corrosion products onto BF residue particles. The results indicate that BF residues represent an attractive low-cost absorbent option for the removal of arsenic in wastewater treatment.

  12. Surface and borehole electromagnetic imaging of conducting contaminant plumes. 1997 annual progress report

    International Nuclear Information System (INIS)

    Berryman, J.G.

    1997-01-01

    'Electromagnetic induction tomography is a promising new tool for imaging electrical conductivity variations in the earth. The EM source field is produced by induction coil (magnetic dipole) transmitters deployed at the surface or in boreholes. Vertical and horizontal component magnetic field detectors are deployed in other boreholes or on the surface. Sources and receivers are typically deployed in a configuration surrounding the region of interest. The goal of this procedure is to image electrical conductivity variations in the earth, much as x-ray tomography is used to image density variations through cross-sections of the body. Although such EM field techniques have been developed and applied, the algorithms for inverting the magnetic data to produce the desired images of electrical conductivity have not kept pace. One of the main reasons for the lag in the algorithm development has been the fact that the magnetic induction problem is inherently three dimensional: other imaging methods such as x-ray and seismic can make use of two-dimensional approximations that are not too far from reality, but the author does not have this luxury in EM induction tomography. In addition, previous field experiments were conducted at controlled test sites that typically do not have much external noise or extensive surface clutter problems often associated with environmental sites. To use the same field techniques in environments more typical of cleanup sites requires a new set of data processing tools to remove the effects of both noise and clutter. The goal of this project is to join theory and experiment to produce enhanced images of electrically conducting fluids underground, allowing better localization of contaminants and improved planning strategies for the subsequent remediation efforts. After explaining the physical context in more detail, this report will summarize the progress made in the first year of this project: (1) on code development and (2) on field tests of

  13. Radiation protection of radioactively contaminated large areas by phytoremediation and subsequent utilization of the contaminated plant residues (PHYTOREST)

    International Nuclear Information System (INIS)

    Mirgorodsky, Daniel; Ollivier, Delphine; Merten, Dirk; Bergmann, Hans; Buechel, Georg; Willscher, Sabine; Wittig, Juliane; Jablonski, Lukasz; Werner, Peter

    2010-01-01

    Much progress has been achieved over the past 20 years in remediating sites contaminated by heavy metal. However, very large contaminated areas have presented major problems to this day because of remediation costs. Phytoremediation is a new, emerging, sustainable technique of remediating areas with low heavy-metal contamination. One advantage of phytoremediation is the comparatively low cost of the process, which may make it usable also on large areas with low levels of contamination. Besides extracting and immobilizing metals, respectively, phytoremediation among other things also contributes to improving soil quality in terms of physics, chemistry, and ecology. Consequently, phytoremediation offers a great potential for the future. Research into phytoremediation of an area contaminated by heavy metals and radionuclides is carried out on a site in a former uranium mining district in Eastern Thuringia jointly by the Friedrich Schiller University, Jena, and the Technical University of Dresden in a project funded by the German Federal Ministry for Education and Research. The project serves to promote the introduction of soft, biocompatible methods of long-term remediation and to develop conceptual solutions to the subsequent utilization of contaminated plant residues. Optimizing area management is in the focus of phytoremediation studies. (orig.)

  14. Coupling of Realistic Rate Estimates with Genomics for Assessing Contaminant Attenuation and Long-Term Plume Containment - Task 4: Modeling - Final Report

    International Nuclear Information System (INIS)

    Robert C. Starr

    2005-01-01

    Trichloroethene (TCE), a common groundwater contaminant, can be degraded under certain conditions by microorganisms that occur naturally in the subsurface. TCE can be degraded under anaerobic conditions to less chlorinated compounds and ultimately into the non-chlorinated, non-hazardous end product, ethene, via anaerobic reductive dechlorination (ARD). ARD is widely recognized as a TCE degradation mechanism, and occurs in active groundwater remediation and can occur during monitored natural attenuation (MNA). MNA relies on natural processes, such as dispersion and degradation, to reduce contaminant concentrations to acceptable levels without active human intervention other than monitoring. TCE can also be biodegraded under aerobic conditions via cometabolism, in which microbial enzymes produced for other purposes fortuitously also react with TCE. In cometabolism, TCE is oxidized directly to non-hazardous products. Cometabolism as a TCE-degrading process under aerobic conditions is less well known than ARD. Natural attenuation is often discounted as a TCE remedial alternative in aerobic conditions based on the paradigm that TCE is biodegradable only under anaerobic conditions. In contrast to this paradigm, TCE was shown to degrade relative to conservative co-contaminants at an environmentally significant rate in a large (approximately 3 km long) TCE plume in aerobic groundwater at the Idaho National Laboratory (INL), and the degradation mechanism was shown to be cometabolism. MNA was selected as the remedy for most of this plume, resulting in a considerable cost savings relative to conventional remedial methods. To determine if cometabolism might be a viable remedy at other sites with TCE-contaminated aerobic groundwater, TCE plumes at Department of Energy (DOE) facilities were screened to evaluate whether TCE commonly degrades in aerobic groundwater, and if degradation rates are fast enough that natural attenuation could be a viable remedy. One hundred and twenty

  15. Zinc species distribution in EDTA-extract residues of zinc-contaminated soil

    International Nuclear Information System (INIS)

    Chang, S.-H.; Wei, Y.-L.; Wang, H. Paul

    2007-01-01

    Soil sample from a site heavily contaminated with >10 wt.% zinc is sampled and extracted with aqueous solutions of ethylene diamine tetra-acetic acid (EDTA) that is a reagent frequently used to extract heavy metals in soil remediation. Three liquid/soil ratios (5/1, 20/1, and 100/1) were used in the extracting experiment. The molecular environment of the residual Zn in the EDTA-extract residues of zinc-contaminated soil is investigated with XANES technique. The results indicate that EDTA does not show considerable preference of chelating for any particular Zn species during the extraction. Zn species distribution in the sampled soil is found to resemble that in all EDTA-extract residues; Zn(OH) 2 is determined as the major zinc species (60-70%), seconded by organic zinc (21-26%) and zinc oxide (9-14%)

  16. Contaminant Release from Residual Waste in Single Shell Tanks at the Hanford Site, Washington, USA - 9276

    International Nuclear Information System (INIS)

    Cantrell, Kirk J.; Krupka, Kenneth M.; Deutsch, William J.; Lindberg, Michael J.

    2009-01-01

    Determinations of elemental and solid-phase compositions, and contaminant release studies have been applied in an ongoing study of residual tank wastes (i.e., waste remaining after final retrieval operations) from five of 149 underground single-shell storage tanks (241-C-103, 241-C-106, 241-C-202, 241-C-203, and 241-S-112) at the U.S. Department of Energy's Hanford Site in Washington State. This work is being conducted to support performance assessments that will be required to evaluate long-term health and safety risks associated with tank site closure. The results of studies completed to date show significant variability in the compositions, solid phase properties, and contaminant release characteristics from these residual tank wastes. This variability is the result of differences in waste chemistry/composition of wastes produced from several different spent fuel reprocessing schemes, subsequent waste reprocessing to remove certain target constituents, tank farm operations that concentrated wastes and mixed wastes between tanks, and differences in retrieval processes used to remove the wastes from the tanks. Release models were developed based upon results of chemical characterization of the bulk residual waste, solid-phase characterization (see companion paper 9277 by Krupka et al.), leaching and extraction experiments, and geochemical modeling. In most cases empirical release models were required to describe contaminant release from these wastes. Release of contaminants from residual waste was frequently found to be controlled by the solubility of phases that could not be identified and/or for which thermodynamic data and/or dissolution rates have not been measured. For example, significant fractions of Tc-99, I-129, and Cr appear to be coprecipitated at trace concentrations in metal oxide phases that could not be identified unambiguously. In the case of U release from tank 241-C-103 residual waste, geochemical calculations indicated that leachate

  17. Residual viral and bacterial contamination of surfaces after cleaning and disinfection.

    Science.gov (United States)

    Tuladhar, Era; Hazeleger, Wilma C; Koopmans, Marion; Zwietering, Marcel H; Beumer, Rijkelt R; Duizer, Erwin

    2012-11-01

    Environmental surfaces contaminated with pathogens can be sources of indirect transmission, and cleaning and disinfection are common interventions focused on reducing contamination levels. We determined the efficacy of cleaning and disinfection procedures for reducing contamination by noroviruses, rotavirus, poliovirus, parechovirus, adenovirus, influenza virus, Staphylococcus aureus, and Salmonella enterica from artificially contaminated stainless steel surfaces. After a single wipe with water, liquid soap, or 250-ppm free chlorine solution, the numbers of infective viruses and bacteria were reduced by 1 log(10) for poliovirus and close to 4 log(10) for influenza virus. There was no significant difference in residual contamination levels after wiping with water, liquid soap, or 250-ppm chlorine solution. When a single wipe with liquid soap was followed by a second wipe using 250- or 1,000-ppm chlorine, an extra 1- to 3-log(10) reduction was achieved, and except for rotavirus and norovirus genogroup I, no significant additional effect of 1,000 ppm compared to 250 ppm was found. A reduced correlation between reduction in PCR units (PCRU) and reduction in infectious particles suggests that at least part of the reduction achieved in the second step is due to inactivation instead of removal alone. We used data on infectious doses and transfer efficiencies to estimate a target level to which the residual contamination should be reduced and found that a single wipe with liquid soap followed by a wipe with 250-ppm free chlorine solution was sufficient to reduce the residual contamination to below the target level for most of the pathogens tested.

  18. Bioavailability of residual polycyclic aromatic hydrocarbons following enhanced natural attenuation of creosote-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Juhasz, Albert L., E-mail: albert.juhasz@unisa.edu.a [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Smith, Euan [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Waller, Natasha [CSIRO Land and Water, Glen Osmond, SA 5064 (Australia); Stewart, Richard [Remediate, Kent Town, SA 5067 (Australia); Weber, John [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia)

    2010-02-15

    The impact of residual PAHs (2250 +- 71 mug total PAHs g{sup -1}) following enhanced natural attenuation (ENA) of creosote-contaminated soil (7767 +- 1286 mug total PAHs g{sup -1}) was assessed using a variety of ecological assays. Microtox{sup TM} results for aqueous soil extracts indicated that there was no significant difference in EC{sub 50} values for uncontaminated, pre- and post-remediated soil. However, in studies conducted with Eisenia fetida, PAH bioaccumulation was reduced by up to 6.5-fold as a result of ENA. Similarly, Beta vulgaris L. biomass yields were increased 2.1-fold following ENA of creosote-contaminated soil. While earthworm and plant assays indicated that PAH bioavailability was reduced following ENA, the residual PAH fraction still exerted toxicological impacts on both receptors. Results from this study highlight that residual PAHs following ENA (presumably non-bioavailable to bioremediation) may still be bioavailable to important receptor organisms such as earthworms and plants. - Residual PAHs in creosote-contaminated soil following enhanced natural attenuation impacted negatively on ecological receptors.

  19. Bioavailability of residual polycyclic aromatic hydrocarbons following enhanced natural attenuation of creosote-contaminated soil

    International Nuclear Information System (INIS)

    Juhasz, Albert L.; Smith, Euan; Waller, Natasha; Stewart, Richard; Weber, John

    2010-01-01

    The impact of residual PAHs (2250 ± 71 μg total PAHs g -1 ) following enhanced natural attenuation (ENA) of creosote-contaminated soil (7767 ± 1286 μg total PAHs g -1 ) was assessed using a variety of ecological assays. Microtox TM results for aqueous soil extracts indicated that there was no significant difference in EC 50 values for uncontaminated, pre- and post-remediated soil. However, in studies conducted with Eisenia fetida, PAH bioaccumulation was reduced by up to 6.5-fold as a result of ENA. Similarly, Beta vulgaris L. biomass yields were increased 2.1-fold following ENA of creosote-contaminated soil. While earthworm and plant assays indicated that PAH bioavailability was reduced following ENA, the residual PAH fraction still exerted toxicological impacts on both receptors. Results from this study highlight that residual PAHs following ENA (presumably non-bioavailable to bioremediation) may still be bioavailable to important receptor organisms such as earthworms and plants. - Residual PAHs in creosote-contaminated soil following enhanced natural attenuation impacted negatively on ecological receptors.

  20. Stabilization of Rocky Flats combustible residues contaminated with plutonium metal and organic solvents

    International Nuclear Information System (INIS)

    Bowen, S.M.; Cisneros, M.R.; Jacobson, L.L.; Schroeder, N.C.; Ames, R.L.

    1998-01-01

    This report describes tests on a proposed flowsheet designed to stabilize combustible residues that were generated at the Rocky Flats Environmental Technology Site (RFETS) during the machining of plutonium metal. Combustible residues are essentially laboratory trash contaminated with halogenated organic solvents and plutonium metal. The proposed flowsheet, designed by RFETS, follows a glovebox procedure that includes (1) the sorting and shredding of materials, (2) a low temperature thermal desorption of solvents from the combustible materials, (3) an oxidation of plutonium metal with steam, and (4) packaging of the stabilized residues. The role of Los Alamos National Laboratory (LANL) in this study was to determine parameters for the low temperature thermal desorption and steam oxidation steps. Thermal desorption of carbon tetrachloride (CCl 4 ) was examined using a heated air stream on a Rocky Flats combustible residue surrogate contaminated with CCl 4 . Three types of plutonium metal were oxidized with steam in a LANL glovebox to determine the effectiveness of this procedure for residue stabilization. The results from these LANL experiments are used to recommend parameters for the proposed RFETS stabilization flowsheet

  1. Allowable residual contamination levels for decommissioning. Part 2. A summary of example results

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Napier, B.A.

    1985-01-01

    This paper contains a description of the results of a study sponsored by UNC Nuclear Industries to determine Allowable Residual Contamination Levels (ARCL) for decommissioning facilities in the 100 Areas of the Hanford Site. ARCL results are presented both for surface contamination remaining in facilities (in dpm/100 cm 2 ) and for unconfined surface and confined subsurface soil conditions (in pCi/g). Two confined soil conditions are considered: contamination at depths between 1 and 4 m, and contamination at depths greater than or equal to 5 m. A set of worksheets are discussed for modifying the ARCL values to accommodate changes in the radionuclide mixture or concentrations, to consider the impacts of radioactive decay, and to predict instrument responses. Finally, a comparison is made between the unrestricted release ARCL values for the 100 Area facilities and existing decommissioning and land disposal regulations. For surface contamination, the comparison shows good agreement for a selected annual dose limit. For soil contamination, the comparison shows good agreement if reasonable modification factors are applied to account for the differences in modeling soil contamination and licensed low-level waste. 6 references, 1 figures, 4 tables

  2. The behaviour of residual contaminants at a former station site, Antarctica

    International Nuclear Information System (INIS)

    Webster, Jenny; Webster, Kerry; Nelson, Peter; Waterhouse, Emma

    2003-01-01

    Minor contamination by metals, phosphorus, and fuel products were found at a former research station site in Antarctica. - In 1994, New Zealand's only mainland Antarctic base, Vanda Station, was removed from the shores of Lake Vanda, in the McMurdo Dry Valleys region of southern Victoria Land, Antarctica. Residual chemical contamination of the station site has been identified, in the form of discrete fuel spills, locally elevated Pb, Zn, Ag and Cd concentrations in soil and elevated Cu, Ni, Co and phosphate concentrations in suprapermafrost fluids in a gully formerly used for domestic washing water disposal. Pathways for contaminant transfer to Lake Vanda, potential environmental impacts and specific remediation/monitoring options are considered. While some contaminants (particularly Zn) could be selectively leached from flooded soil, during a period of rising lake level, the small area of contaminated soils exposed and low level of contamination suggests that this would not adversely affect either shallow lake water quality or the growth of cyanobacteria. Phosphate-enhanced growth of the latter may, however, be a visible consequence of the minor contamination occurring at this site

  3. Hanford Tank 241-C-106: Residual Waste Contaminant Release Model and Supporting Data

    International Nuclear Information System (INIS)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Schaef, Herbert T.

    2005-01-01

    CH2M HILL is producing risk/performance assessments to support the closure of single-shell tanks at the DOE's Hanford Site. As part of this effort, staff at PNNL were asked to develop release models for contaminants of concern that are present in residual sludge remaining in tank 241-C-106 (C-106) after final retrieval of waste from the tank. This report provides the information developed by PNNL

  4. 3-D spectral Induced Polarization (IP) imaging: Non-invasive characterization of contaminant plumes. Annual progress report, September 15, 1996 - September 14, 1997

    International Nuclear Information System (INIS)

    Frye, K.M.; Lesmes, D.P.; Morgan, F.D.; Rodi, W.; Shi, W.; Sturrock, J.

    1997-01-01

    'The objective of this project is to develop the scientific basis for characterizing contaminant plumes in the earth''s subsurface using field measurements of induced polarization (IP) effects. The first-year accomplishments are (1) laboratory experiments on fluid-saturated sandstones quantifying the dependence of spectral IP responses on solution chemistry and rock micro-geometry; (2) library research on the current understanding of electromagnetic coupling effects on IP data acquired in the field: and (3) development of prototype forward modeling and inversion algorithms for interpreting IP data in terms of 3-D models of complex resistivity.'

  5. Contaminant Leach Testing of Hanford Tank 241-C-104 Residual Waste

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Snyder, Michelle M.V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Guohui [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Buck, Edgar C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-07-01

    Leach testing of Tank C-104 residual waste was completed using batch and column experiments. Tank C-104 residual waste contains exceptionally high concentrations of uranium (i.e., as high as 115 mg/g or 11.5 wt.%). This study was conducted to provide data to develop contaminant release models for Tank C-104 residual waste and Tank C-104 residual waste that has been treated with lime to transform uranium in the waste to a highly insoluble calcium uranate (CaUO4) or similar phase. Three column leaching cases were investigated. In the first case, C-104 residual waste was leached with deionized water. In the second case, crushed grout was added to the column so that deionized water contacted the grout prior to contacting the waste. In the third case, lime was mixed in with the grout. Results of the column experiments demonstrate that addition of lime dramatically reduces the leachability of uranium from Tank C-104 residual waste. Initial indications suggest that CaUO4 or a similar highly insoluble calcium rich uranium phase forms as a result of the lime addition. Additional work is needed to definitively identify the uranium phases that occur in the as received waste and the waste after the lime treatment.

  6. Biogeochemical and isotopic gradients in a BTEX/PAH contaminant plume: Model-based interpretation of a high-resolution field data set

    DEFF Research Database (Denmark)

    Prommer, H.; Anneser, B.; Rolle, Massimo

    2009-01-01

    of toluene, which is the most rapidly degrading compound and the most important reductant at the site. The resulting depth profiles at the observation well show distinct differences between the small isotopic enrichment in the contaminant plume core and the much stronger enrichment of up to 3.3 parts per......A high spatial resolution data set documenting carbon and sulfur isotope fractionation at a tar oil-contaminated, sulfate-reducing field site was analyzed with a reactive transport model. Within a comprehensive numerical model, the study links the distinctive observed isotope depth profiles...... with the degradation of various monoaromatic and polycyclic aromatic hydrocarbon compounds (BTEX/PAHs) under sulfate-reducing conditions. In the numerical model, microbial dynamics were simulated explicitly and isotope fractionation was directly linked to the differential microbial uptake of lighter and heavier carbon...

  7. Thermal plumes and micro-contaminants release from power plants in water bodies. Development of innovative software tools to support plant management and real case applications

    International Nuclear Information System (INIS)

    Guandalini, R.

    2007-01-01

    Environmental issues are a fundamental aspect of energy generation by thermal power plants. Numerical modeling can be used to develop innovative software tools to support plant management and to analyze critical scenarios also considering meteorology forecasts. Compliance with regulatory obligations of thermal/contaminant plumes and prediction of water body physical properties at the intake/discharge location can be performed by real time systems, in order to optimize plant operations and to evaluate the amount of energy that will be generated. A procedure coupling hydrodynamic and water quality modeling for the prediction of possible areas of accumulation of micro-contaminants in a short, medium and long period is also presented. Finally, applications of thermal/pollutant prediction systems and numerical modeling of particular environmental aspects of energy production and transport are shown (e.g. chlorine diffusion from a HVDC marine anode, impact on aquatic ecosystems in coastal regions). (author)

  8. Allowable residual-contamination levels for decommissioning facilities in the 100 areas of the Hanford Site

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Napier, B.A.

    1983-07-01

    This report contains the results of a study sponsored by UNC Nuclear Industries to determine Allowable Residual Contamination Levels (ARCL) for five generic categories of facilities in the 100 Areas of the Hanford Site. The purpose of this study is to provide ARCL data useful to UNC engineers in conducting safety and cost comparisons for decommissioning alternatives. The ARCL results are based on a scenario/exposure-pathway analysis and compliance with an annual dose limit for three specific modes of future use of the land and facilities. These modes of use are restricted, controlled, and unrestricted. The information on ARCL values for restricted and controlled use provided by this report is intended to permit a full consideration of decommissioning alternatives. ARCL results are presented both for surface contamination remaining in facilities (in dpm/100 cm 2 ), and for unconfined surface and confined subsurface soil conditions (in pCi/g). Two confined soil conditions are considered: contamination at depths between 1 and 4 m, and contamination at depths greater than or equal to 5 m. A set of worksheets are presented in an appendix for modifying the ARCL values to accommodate changes in the radionuclide mixture or concentrations, to consider the impacts of radioactive decay, and to predict instrument responses. Finally, a comparison is made between the unrestricted release ARCL values for the 100 Area facilities and existing decommissioning and land disposal regulations. For surface contamination, the comparison shows good agreement. For soil contamination, the comparison shows good agreement if reasonable modification factors are applied to account for the differences in modeling soil contamination and licensed low-level waste

  9. Investigation on reusing water treatment residuals to remedy soil contaminated with multiple metals in Baiyin, China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Changhui; Zhao, Yuanyuan [The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875 (China); Pei, Yuansheng, E-mail: yspei@bnu.edu.cn [The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875 (China)

    2012-10-30

    Highlights: Black-Right-Pointing-Pointer Fe/Al water treatment residuals (FARs) can stabilize As, Pb, Ni, Zn, Cr and Cu. Black-Right-Pointing-Pointer FARs cannot stabilize Ba and Cd. Black-Right-Pointing-Pointer The properties of FARs and soil affect the FARs' ability of stabilizing metals. - Abstract: In this work, the remediation of soils contaminated with multiple metals using ferric and alum water treatment residuals (FARs) in Baiyin, China, was investigated. The results of metals fractionation indicated that after the soil was treated with FARs, arsenic (As), lead (Pb), nickel (Ni), zinc (Zn) and copper (Cu) could be transformed into more stable forms, i.e., As bound in crystalline Fe/Al oxides and other metals in the oxidable and residual forms. However, the forms of chromium (Cr) and cadmium (Cd) were unaffected. Interestingly, due to the effect of FARs, barium (Ba) was predominantly transformed into more mobile forms. The bioaccessibility extraction test demonstrated that the FARs reduced the bioaccessibility of As by 25%, followed by Cu, Cr, Zn, Ni and Pb. The bioaccessibility of Cd and Ba were increased; in particular, there was an increase of 41% for Ba at the end of the test. In conclusion, the FARs can be used to remedy soil contaminated with multiple metals, but comprehensive studies are needed before practical applications of this work.

  10. Investigation on reusing water treatment residuals to remedy soil contaminated with multiple metals in Baiyin, China

    International Nuclear Information System (INIS)

    Wang, Changhui; Zhao, Yuanyuan; Pei, Yuansheng

    2012-01-01

    Highlights: ► Fe/Al water treatment residuals (FARs) can stabilize As, Pb, Ni, Zn, Cr and Cu. ► FARs cannot stabilize Ba and Cd. ► The properties of FARs and soil affect the FARs’ ability of stabilizing metals. - Abstract: In this work, the remediation of soils contaminated with multiple metals using ferric and alum water treatment residuals (FARs) in Baiyin, China, was investigated. The results of metals fractionation indicated that after the soil was treated with FARs, arsenic (As), lead (Pb), nickel (Ni), zinc (Zn) and copper (Cu) could be transformed into more stable forms, i.e., As bound in crystalline Fe/Al oxides and other metals in the oxidable and residual forms. However, the forms of chromium (Cr) and cadmium (Cd) were unaffected. Interestingly, due to the effect of FARs, barium (Ba) was predominantly transformed into more mobile forms. The bioaccessibility extraction test demonstrated that the FARs reduced the bioaccessibility of As by 25%, followed by Cu, Cr, Zn, Ni and Pb. The bioaccessibility of Cd and Ba were increased; in particular, there was an increase of 41% for Ba at the end of the test. In conclusion, the FARs can be used to remedy soil contaminated with multiple metals, but comprehensive studies are needed before practical applications of this work.

  11. Control criteria for residual contamination in materials considered for recycle and reuse

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Hill, R.L.; Aaberg, R.L.

    1993-11-01

    Pacific Northwest Laboratory (PNL) is collecting data and conducting technical analyses to support the US Department of Energy (DOE), Office of Environmental Guidance, Air, Water, and Radiation Division (DOE/EH-232) in determining the feasibility of developing radiological control criteria for recycling or reuse of metals or equipment containing residual radioactive contamination from DOE operations. The criteria, framed as acceptable concentrations for release of materials for recycling or reuse, will be risk-based and will be developed through analysis of radiation exposure scenarios and pathways. The analysis will include evaluation of relevant radionuclides, potential mechanisms of exposure, and non-health-related impacts of residual radioactivity on electronics and film. The analyses will consider 42 key radionuclides that are generated during DOE operations and may be contained in recycled or reused metals or equipment

  12. Hanford Tank 241-C-106: Impact of Cement Reactions on Release of Contaminants from Residual Waste

    International Nuclear Information System (INIS)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Schaef, Herbert T.

    2006-01-01

    The CH2M HILL Hanford Group, Inc. (CH2M HILL) is producing risk/performance assessments to support the closure of single-shell tanks at the U.S. Department of Energy's Hanford Site. As part of this effort, staff at Pacific Northwest National Laboratory were asked to develop release models for contaminants of concern that are present in residual sludge remaining in tank 241-C-106 (C-106) after final retrieval of waste from the tank. Initial work to produce release models was conducted on residual tank sludge using pure water as the leaching agent. The results were reported in an earlier report. The decision has now been made to close the tanks after waste retrieval with a cementitious grout to minimize infiltration and maintain the physical integrity of the tanks. This report describes testing of the residual waste with a leaching solution that simulates the composition of water passing through the grout and contacting the residual waste at the bottom of the tank.

  13. Dual wall reverse circulation drilling with multi-level groundwater sampling for groundwater contaminant plume delineation at Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    International Nuclear Information System (INIS)

    Smuin, D.R.; Morti, E.E.; Zutman, J.L.; Pickering, D.A.

    1995-01-01

    Dual wall reverse circulation (DWRC) drilling was used to drill 48 borings during a groundwater contaminant investigation at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky. This method was selected as an alternative to conventional hollow stem auger drilling for a number of reasons, including the expectation of minimizing waste, increasing the drilling rate, and reducing the potential for cross contamination of aquifers. Groundwater samples were collected from several water-bearing zones during drilling of each borehole. The samples were analyzed for volatile organic compounds using a field gas chromatograph. This approach allowed the investigation to be directed using near-real-time data. Use of downhole geophysical logging, in conjunction with lithologic descriptions of borehole cuttings, resulted in excellent correlation of the geology in the vicinity of the contaminant plume. The total volume of cuttings generated using the DWRC drilling method was less than half of what would have been produced by hollow stem augering; however, the cuttings were recovered in slurry form and had to be dewatered prior to disposal. The drilling rate was very rapid, often approaching 10 ft/min; however, frequent breaks to perform groundwater sampling resulted in an average drilling rate of < 1 ft/min. The time required for groundwater sampling could be shortened by changing the sampling methodology. Analytical results indicated that the drilling method successfully isolated the various water bearing zones and no cross contamination resulted from the investigation

  14. Allowable residual contamination levels: transuranic advanced disposal systems for defense waste

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Napier, B.A.

    1982-01-01

    An evaluation of advanced disposal systems for defense transuranic (TRU) wastes is being conducted using the Allowable Residual Contamination Level (ARCL) method. The ARCL method is based on compliance with a radiation dose rate limit through a site-specific analysis of the potential for radiation exposure to individuals. For defense TRU wastes at the Hanford Site near Richland, Washington, various advanced disposal techniques are being studied to determine their potential for application. This paper presents a discussion of the results of the first stage of the TRU advanced disposal systems project

  15. Residual radioactive contamination of the Maralinga range from nuclear weapons tests conducted in 1956 and 1957

    International Nuclear Information System (INIS)

    Cooper, M.B.; Duggleby, J.C.; Kotler, L.H.; Wise, K.N.

    1978-12-01

    Detailed geographical distributions and concentrations of long-lived radionuclides remaining from the major trials of nuclear weapons conducted at Maralinga in 1956 and 1957 are presented. It is shown that residual contamination due to fission products - mainly strontium-90, caesium-137 and europium-155 - are well below levels that could constitute a health hazard to occupants of the area. In the regions near the ground zeroes however, long-lived neutron activation products in soil - mainly cobalt-60 and europium-152 - are present in sufficient abundance to give rise to gamma-radiation dose-rates up to 2 milliroentgen per hour, which exceed maximum recommended dose-rates for continuous occupancy

  16. Remediation of cadmium contaminated water and soil using vinegar residue biochar.

    Science.gov (United States)

    Li, Yuxin; Pei, Guangpeng; Qiao, Xianliang; Zhu, Yuen; Li, Hua

    2018-06-01

    This study investigated a new biochar produced from vinegar residue that could be used to remediate cadmium (Cd)-contaminated water and soil. Aqueous solution adsorption and soil incubation experiments were performed to investigate whether a biochar prepared at 700 °C from vinegar residue could efficiently adsorb and/or stabilize Cd in water and soil. In the aqueous solution adsorption experiment, the Cd adsorption process was best fitted by the pseudo-second-order kinetic and Freundlich isotherm models. If the optimum parameters were used, i.e., pH 5 or higher, a biochar dosage of 12 g L -1 , a 10 mg L -1 Cd initial concentration, and 15-min equilibrium time, at 25 °C, then Cd removal could reach about 100%. The soil incubation experiment evaluated the biochar effects at four different application rates (1, 2, 5, and 10% w/w) and three Cd contamination rates (0.5, 1, and 2.5 mg kg -1 ) on soil properties and Cd fractionation. Soil pH and organic matter increased after adding biochar, especially at the 10% application rate. At Cd pollution levels of 1.0 or 2.5 mg kg -1 , a 10% biochar application rate was most effective. At 0.5 mg Cd kg -1 soil, a 5% biochar application rate was most efficient at transforming the acid extractable and easily reducible Cd fractions to oxidizable and residual Cd. The results from this study demonstrated that biochar made from vinegar residue could be a new and promising alternative biomass-derived material for Cd remediation in water and soil.

  17. Three-dimensional analysis of future groundwater flow conditions and contaminant plume transport in the Hanford Site unconfined aquifer system: FY 1996 and 1997 status report

    Energy Technology Data Exchange (ETDEWEB)

    Cole, C.R.; Wurstner, S.K.; Williams, M.D.; Thorne, P.D.; Bergeron, M.P.

    1997-12-01

    A three-dimensional numerical model of groundwater flow and transport, based on the Coupled Fluid Energy, and Solute Transport (CFEST) code, was developed for the Hanford Site to support the Hanford Groundwater Project (HGWP), managed by Pacific Northwest National Laboratory. The model was developed to increase the understanding and better forecast the migration of several contaminant plumes being monitored by the HGWP, and to support the Hanford Site Composite Analysis for low-level waste disposal in the 200-Area Plateau. Recent modeling efforts have focused on continued refinement of an initial version of the three-dimensional model developed in 1995 and its application to simulate future transport of selected contaminant plumes in the aquifer system. This version of the model was updated using a more current version of the CFEST code called CFEST96. Prior to conducting simulations of contaminant transport with the three-dimensional model, a previous steady-state, two-dimensional model of the unconfined aquifer system was recalibrated to 1979 water-table conditions with a statistical inverse method implemented in the CFEST-INV computer code. The results of the recalibration were used to refine the three-dimensional conceptual model and to calibrate it with a conceptualization that preserves the two-dimensional hydraulic properties and knowledge of the aquifer`s three-dimensional properties for the same 1979 water-table conditions. The transient behavior of the three-dimensional flow model was also calibrated by adjusting model storage properties (specific yield) until transient water-table predictions approximated observed water-table elevations between 1979 and 1996.

  18. Three-dimensional analysis of future groundwater flow conditions and contaminant plume transport in the Hanford Site unconfined aquifer system: FY 1996 and 1997 status report

    International Nuclear Information System (INIS)

    Cole, C.R.; Wurstner, S.K.; Williams, M.D.; Thorne, P.D.; Bergeron, M.P.

    1997-12-01

    A three-dimensional numerical model of groundwater flow and transport, based on the Coupled Fluid Energy, and Solute Transport (CFEST) code, was developed for the Hanford Site to support the Hanford Groundwater Project (HGWP), managed by Pacific Northwest National Laboratory. The model was developed to increase the understanding and better forecast the migration of several contaminant plumes being monitored by the HGWP, and to support the Hanford Site Composite Analysis for low-level waste disposal in the 200-Area Plateau. Recent modeling efforts have focused on continued refinement of an initial version of the three-dimensional model developed in 1995 and its application to simulate future transport of selected contaminant plumes in the aquifer system. This version of the model was updated using a more current version of the CFEST code called CFEST96. Prior to conducting simulations of contaminant transport with the three-dimensional model, a previous steady-state, two-dimensional model of the unconfined aquifer system was recalibrated to 1979 water-table conditions with a statistical inverse method implemented in the CFEST-INV computer code. The results of the recalibration were used to refine the three-dimensional conceptual model and to calibrate it with a conceptualization that preserves the two-dimensional hydraulic properties and knowledge of the aquifer's three-dimensional properties for the same 1979 water-table conditions. The transient behavior of the three-dimensional flow model was also calibrated by adjusting model storage properties (specific yield) until transient water-table predictions approximated observed water-table elevations between 1979 and 1996

  19. Control levels for residual contamination in materials considered for recycle and reuse

    International Nuclear Information System (INIS)

    Hill, R.L.; Aaberg, R.L.; Baker, D.A.; Kennedy, W.E. Jr.

    1993-09-01

    Pacific Northwest Laboratory (PNL) is collecting data and conducting technical analyses to support joint efforts by the U.S. Department of Energy (DOE), Office of Environmental Guidance, Air, Water and Radiation Division (DOE/EH-232); by the U.S. Environmental Protection Agency (EPA); and by the U.S. Nuclear Regulatory Commission (NRC) to develop radiological control criteria for the recycle and reuse of scrap materials and equipment that contain residual radioactive contamination. The initial radiological control levels are the concentrations in or on materials considered for recycle or reuse that meet the individual (human) or industrial (electronics/film) dose criteria. The analysis identifies relevant radionuclides, potential mechanisms of exposure, and methods to determine possible non-health-related impacts from residual radioactive contamination in materials considered for recycle or reuse. The generic methodology and scenarios described here provide a basic framework for numerically deriving radiological control criteria for recycle or reuse. These will be adequately conservative for most situations

  20. Evaluation of remediation techniques in soils affected by residual contamination with heavy metals and arsenic.

    Science.gov (United States)

    García-Carmona, M; Romero-Freire, A; Sierra Aragón, M; Martínez Garzón, F J; Martín Peinado, F J

    2017-04-15

    Residual soil pollution from the Aznalcóllar mine spill is still a problem in some parts of the affected area, today converted in the Guadiamar Green Corridor. Dispersed spots of polluted soils, identified by the absence of vegetation, are characterized by soil acid pH and high concentrations of As, Pb, Cu and Zn. Ex situ remediation techniques were performed with unrecovered soil samples. Landfarming, Composting and Biopiles techniques were tested in order to immobilize pollutants, to improve soil properties and to promote vegetation recovery. The effectiveness of these techniques was assessed by toxicity bioassays: Lactuca sativa L. root elongation test, Vibrio fischeri bioluminescence reduction test, soil induced respiration test, and Eisenia andrei survival and metal bioaccumulation tests. Landfarming and Composting were not effective techniques, mainly due to the poor improvement of soil properties which maintained high soluble concentrations of Zn and Cu after treatments. Biopile technique, using adjacent recovered soils in the area, was the most effective action in the reduction of soil toxicity; the improvement of soil properties and the reduction in pollutants solubility were key to improve the response of the tested organisms. Therefore, the mixture of recovered soils with polluted soils in the areas affected by residual contamination is considered a more suitable technique to reduce the residual pollution and to promote the complete soil recovery in the Guadiamar Green Corridor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Carbon speciation in ash, residual waste and contaminated soil by thermal and chemical analyses.

    Science.gov (United States)

    Kumpiene, Jurate; Robinson, Ryan; Brännvall, Evelina; Nordmark, Désirée; Bjurström, Henrik; Andreas, Lale; Lagerkvist, Anders; Ecke, Holger

    2011-01-01

    Carbon in waste can occur as inorganic (IC), organic (OC) and elemental carbon (EC) each having distinct chemical properties and possible environmental effects. In this study, carbon speciation was performed using thermogravimetric analysis (TGA), chemical degradation tests and the standard total organic carbon (TOC) measurement procedures in three types of waste materials (bottom ash, residual waste and contaminated soil). Over 50% of the total carbon (TC) in all studied materials (72% in ash and residual waste, and 59% in soil) was biologically non-reactive or EC as determined by thermogravimetric analyses. The speciation of TOC by chemical degradation also showed a presence of a non-degradable C fraction in all materials (60% of TOC in ash, 30% in residual waste and 13% in soil), though in smaller amounts than those determined by TGA. In principle, chemical degradation method can give an indication of the presence of potentially inert C in various waste materials, while TGA is a more precise technique for C speciation, given that waste-specific method adjustments are made. The standard TOC measurement yields exaggerated estimates of organic carbon and may therefore overestimate the potential environmental impacts (e.g. landfill gas generation) of waste materials in a landfill environment. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Allowable Residual Contamination Levels in soil for decommissioning the Shippingport Atomic Power Station site

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Napier, B.A.; Soldat, J.K.

    1983-09-01

    As part of decommissioning the Shippingport Atomic Power Station, a fundamental concern is the determination of Allowable Residual Contamination Levels (ARCL) for radionuclides in the soil at the site. The ARCL method described in this report is based on a scenario/exposure-pathway analysis and compliance with an annual dose limit for unrestricted use of the land after decommissioning. In addition to naturally occurring radionuclides and fallout from weapons testing, soil contamination could potentially come from five other sources. These include operation of the Shippingport Station as a pressurized water reactor, operations of the Shippingport Station as a light-water breeder, operation of the nearby Beaver Valley reactors, releases during decommissioning, and operation of other nearby industries, including the Bruce-Mansfield coal-fired power plants. ARCL values are presented for 29 individual radionculides and a worksheet is provided so that ARCL values can be determined for any mixture of the individual radionuclides for any annual dose limit selected. In addition, a worksheet is provided for calculating present time soil concentration value that will decay to the ARCL values after any selected period of time, such as would occur during a period of restricted access. The ARCL results are presented for both unconfined (surface) and confined (subsurface) soil contamination. The ARCL method and results described in this report provide a flexible means of determining unrestricted-use site release conditions after decommissioning the Shippingport Atomic Power Station

  3. A method for determining allowable residual contamination levels of radionuclide mixtures in soil

    International Nuclear Information System (INIS)

    Napier, B.A.

    1982-05-01

    An important consideration in the disposal of radioactive wastes, and consequently in the preparation of plans for remedial actions at contaminated sites, is the amount of radioactive contamination that may be allowed to remain at any particular waste site. The allowable residual contamination level (ARCL) is dependent on the radiation dose limit imposed, the physical and environmental characteristics of the waste site, and the time at which exposure to the wastes is assumed to occur. The steps in generating an ARCL are generally as follows: (1) develop plausible, credible site-specific exposure scenario; (2) calculate maximum annual radiation doses to an individual for each radionuclide based on the existing physical characteristics of the waste site and the site-specific exposure scenario; (3) calculate the ARCL for the dose limit desired, including all radionuclides present, uncorrected for site cleanup or barrier considerations; and (4) apply any corrections for proposed cleanup activity or addition of barriers to waste migration or uptake to obtain the ARCL applicable to the proposed action. Use of this method allows appropriate application of resources to achieve uniform compliance with a single regulatory standard, i.e., a radiation dose rate limit. Application and modification of the ARCL method requires appropriate models of the environmental transport and fate of radionuclides. Example calculations are given for several specific waste forms and waste site types in order to demonstrate the technique and generate comparisons with other approaches

  4. Residual contamination from Cs-137 in the Sondrio area (Lombardy - Italy)

    International Nuclear Information System (INIS)

    Rimoldi, E.M.; Leonardi, L.; Cavallone, E.; Bignazzi, R.; Galimberti, A.

    2000-01-01

    The authors conducted the investigations on the contamination by Cs-137, resulting from Chernobyl's Accident, in the Sondrio area (Lombardy, Italy). Analyses were performed with NaI (T1) spectrometer. 130 samples collected from superficial earth layer (up to 15 cm) and deep earth layer (from 15 to 30 cm) of woods and meadows, pond's mud, mosses, mushrooms, wild wood fruits, forages, striated muscle from deer, chamois and roe deer, goat's and cow's milk, and running and stagnant water, were studied. Superficial earth samples always showed a higher Cs-137 concentration compared to deep earth samples, their mean activities being 68 Bq/kg (sup. wood) and 18 Bq/kg (sup. meadow). In 1 sample from superficial wood earth in Val Belsivo, the concentration was 1109 Bq/kg. The mud samples had a mean Cs-137 concentration of 96 Bq/kg. Cs-137 was always present in mosses with a mean activity of 234 Bq/kg, whereas in mushrooms contamination was continuous (mean, 63 Bq/kg). Cs-137 was absent in wild wood fruits and in forages except for one sample of bilberry (12 Bq/Kg) and one sample of forage (54 Bq/Kg). In the striated muscle samples from wild animals, chamois always showed high Cs-137 concentration (29 Bq/kg), but was intermediate in roe deer (18 Bq/kg) and lowest in deer (5 Bq/kg). In 4 deer and 4 roe deer, contamination was undetectable. Running and stagnant waters, and cow's milk were not contaminated whereas some Cs-137 activities were detected in goat milk samples (18 Bq/kg). It is concluded that residual contamination from Chernobyl's accident in the investigated areas has by now just become a scientific interest and no longer a sanitary issue, as the contamination levels detected in all the samples are clearly below the maximal admissible levels established by the European Gazettes. However, it is interesting to note that the recycling of Cs-137 is more present in wood, confirming the delicate environmental balance of this ecosystem. The routine radio

  5. Assessment of the potential radiological impact of residual contamination in the Maralinga and Emu areas

    International Nuclear Information System (INIS)

    Haywood, S.M.; Smith, J.

    1990-10-01

    The report presents an assessment of potential doses to future inhabitants of the Maralinga and Emu areas of Southern Australia, where nuclear weapons tests in the 1950s and 1960s resulted in widespread residual radioactive contamination. Annual effective doses of several millisieverts would be expected to result from continual occupancy within contours enclosing areas of several hundred square kilometres. Larger predicted annual effective doses - of the order of 0.5 Sv -would be expected to occur from 100% occupancy in small regions immediately surrounding the test sites, but continual occupancy of such areas is highly unlikely because of their small size. The most significant dose pathways are inhalation of resuspended activity and ingestion of soil by infants. An analysis of the effects of uncertainties in the dose calculation indicated the uncertainty distribution on predicted doses from the inhalation pathway. (author)

  6. Investigation of vitreous and crystalline ceramic materials for immobilization of alpha-contaminated residues

    International Nuclear Information System (INIS)

    Palmer, C.R.; Mellinger, G.B.; Rusin, J.M.

    1981-01-01

    Experimental investigations of two alternatives for immobilizing dispersible solid wastes contaminated with alpha-emitting radionuclides are reviewed. Borosilicate glasses and sintered silicate ceramics are being studied for such wastes, and results so far indicate both may offer attractive alternatives to waste generators. Waste oxide solubilities, de-vitrification behaviour and effects of residual carbon are examined for glasses incorporating incinerator ash and hydrated ferric oxide sludge. Glasses will accommodate these wastes at loadings of 30-60 wt% while maintaining good performance characteristics. A brief comparative evaluation of cold-pressed and sintered ceramics is also described. The effects on process and product properties of the choice of additives, waste loading and sintering temperature were determined. This approach also appears to promise economic waste loadings while achieving relatively durable waste forms. (author)

  7. Allowable residual contamination levels for decommissioning. Part 1. A description of the method

    International Nuclear Information System (INIS)

    Napier, B.A.; Kennedy, W.E. Jr.

    1984-10-01

    This paper contains a description of the methods used in a study sponsored by UNC Nuclear Industries to determine Allowable Residual Contamination Levels (ARCL) for decommissioning facilities in the 100 Areas of the Hanford Site. The ARCL method is based on a scenario/exposure-pathway analysis and compliance with an annual dose limit for three specific modes of future use of the land and facilities. Thes modes of use are restricted, controlled, and unrestricted. The information on ARCL values for restricted and controlled use is intended to permit a full consideration of decommissioning alternatives. The analysis results in site-specific ARCL values that can be used for determining compliance with any annual dose limit selected. This flexibility permits proper consideration of field situations involving the radionuclide mixtures and physical conditions encountered. In addition, this method permits a full determination of as low as reasonably achievable (ALARA) conditions

  8. Leaching and soil/groundwater transport of contaminants from coal combustion residues

    International Nuclear Information System (INIS)

    Hjelmar, O.; Hansen, E.A.; Larsen, F.; Thomassen, H.

    1992-01-01

    In this project the results of accelerated laboratory leaching tests on coal fly ash and flue gas desulfurization (FGD) products from the spray dryer absorption process (SDA) were evaluated by comparison to the results of large scale lysimeter leaching tests on the same residues. The mobility of chromium and molybdenum - two of the kev contaminants of coal combustion residue leachates - in various typical soil types was investigated by batch and column methods in the laboratory. Some of the results were confirmed by field observations at an old coal fly ash disposal site and by a lysimeter attenuation test with coal fly ash leachate on a clayed till. A large number of groundwater transport models and geochemical models were reviewed, and two of the models (Gove-Stollenwerk and CHMTRNS) were modified and adjusted and used to simulate column attenuation tests performed in the laboratory. One of the models (Grove-Stollenwerk) was used to illustrate a recommended method of environmental impact assessment, using lysimeter leaching data and laboratory column attenuation data to describe the emission and migration of Mo from a coal fly ash disposal site

  9. Temporal variations in natural attenuation of chlorinated aliphatic hydrocarbons in eutrophic river sediments impacted by a contaminated groundwater plume

    NARCIS (Netherlands)

    Hamonts, K.; Kuhn, T.; Vos, J.; Maesen, M.; Kalka, H.; Smidt, H.; Springael, D.; Meckenstock, R.U.; Dejonghe, W.

    2012-01-01

    Chlorinated aliphatic hydrocarbons (CAHs) often discharge into rivers as contaminated groundwater base flow. Biotrans formation, sorption and dilution of CAHs in the impacted river sediments have been reported to reduce discharge, but the effect of temporal variations in environmental conditions on

  10. Residual viral and bacterial contamination of surfaces after cleaning and disinfection

    NARCIS (Netherlands)

    Tuladhar, E.; Hazeleger, W.C.; Koopmans, M.; Zwietering, M.H.; Beumer, R.R.; Duizer, E.

    2012-01-01

    Environmental surfaces contaminated with pathogens can be sources of indirect transmission, and cleaning and disinfection are common interventions focused on reducing contamination levels. We determined the efficacy of cleaning and disinfection procedures for reducing contamination by noroviruses,

  11. Pyrolysis of fibre residues with plastic contamination from a paper recycling mill: Energy recoveries

    International Nuclear Information System (INIS)

    Brown, Logan Jeremy; Collard, François-Xavier; Görgens, Johann

    2017-01-01

    Highlights: • Pyrolysis of fibre-plastics residues from paper recycling mill into fuel products. • Product with remarkable energy content up to 42.8 MJ/kg. • Influence of temperature on the product yields and fuel properties. • Effect of plastic composition on product properties. - Abstract: Pyrolysis is a promising technology for the production of marketable energy products from waste mixtures, as it decomposes heterogeneous material into homogenous fuel products. This research assessed the ability of slow pyrolysis to convert three waste streams, composed of fibre residues contaminated with different plastic mixtures, into char and tarry phase products at three different temperatures (300, 425 and 550 °C). The products were characterised in terms of mass yield, higher heating value (HHV) and gross energy conversion (EC). Significant amounts of hydrocarbon plastics in the feed materials increased the calorific values of the char (up to 32.9 MJ/kg) and tarry phase (up to 42.8 MJ/kg) products, comparable to high volatile bituminous A coal and diesel respectively. For all three waste streams converted at 300 °C, the majority of the energy in the feedstock was recovered in the char product (>80%), while deoxygenation of fibre component resulted in char with increased calorific value (up to 31.6 MJ/kg) being produced. Pyrolysis at 425 °C for two of the waste streams containing significant amounts of plastic produced both a valuable char and tarry phase, which resulted in an EC greater than 74%. Full conversion of plastic at 550 °C increased the tarry phase yield but dramatically decreased the char HHV. The influence of temperature on product yield and HHV was discussed based on the pyrolysis mechanisms and in relation to the plastic composition of the waste streams.

  12. Transfer of heavy metals to biota after remediation of contaminated soils with calcareous residues.

    Science.gov (United States)

    Pérez-Sirvent, Carmen; Martínez-Sánchez, Maria Jose; Agudo, Ines; Gonzalez, Eva; Perez-Espinosa, Victor; Belen Martínez, Lucia; Hernández, Carmen; García-Fernandez, Antonio Juan; Bech, Jaime

    2013-04-01

    A study was carried out to evaluate the assimilation of heavy metals by three types of horticultural plants (broccoli, lettuce and leek), different parts of which are destined for human and farm animals consumption (leaves, roots, fruits). Five consecutive crops of each vegetable were obtained in greenhouse. In a second stage, experiments were carried out with rabbits fed with such vegetables. The plants were cultivated in four types of soil. The first one was contaminated by heavy metals (S1), the second was a uncontaminated soil (blank soil) (S2), the third was the material obtained by mixing S1 with residues coming from demolition and construction activities (S3); while the fourth was the result of remediating S1 with lime residues coming from quarries (S4). The total metal content (As, Pb, Cd and Zn) of the soil samples, rizosphere, leached water and vegetable samples, were measured, and both the translocation and bioconcentration factors (TF and BCF, respectively) were calculated. In the second stage, the effect caused in rabbits fed with the vegetables was monitorized using both external observation and the analysis of blood, urine, and the levels of metals in muscles, liver and kidney. The statistical analysis of the results obtained showed that there were no significant differences in the heavy metal levels for the vegetables cultivated in S2, S3 and S4. The results for soil sample S1 did not have a normal distribution since the growing of the vegetables were not homogeneous and also strongly dependent on the type of vegetal. As regards the effect caused in rabbits, significant differences were observed for the animals fed with plants cultivated in S1 compared with the others.

  13. Contamination of food with residues of antibiotics in the sulphonamide class, risk can be avoided

    Directory of Open Access Journals (Sweden)

    Carmen Lidia Chitescu,

    2010-12-01

    Full Text Available Sulfadimethoxine, sulfamethoxazole, sulfaquinoxaline and sulfadiazine are the most common usedsulfonamides in veterinary practice. The recommended withdrawal periods if not observed before slaughteringof the medicated animals, the products may obtain from such animals may be contaminated with residue. Theinterest in having reliable methods able to detect low amounts of sulfonamides in food is very actual. In thisstudy, a multiresidue analysis was performed to simultaneously determine those four sulfonamides in chickenmuscle tissue by the Waters LC.Criteria of validation: specificity, accuracy, precision, limit of detection, limit of quantification, and linearity,according to the European Commission Decision 2002/657/EC, show that the method can detect differentkinds of sulfonamides within one run, without mass spectrometry analyses, or Fluor metric derivatization ofanalyts.The method is accurate, simple, economical in both time and cost, capable of detecting sulfonamidesresidues below the maximum residue limits (MRL and easy to perform to routine samples, in normal conditionof laboratory.The sulfonamides were extracted with acetonitrile and acetone and dichloromethane. N-hexane wasadded for defeating the sample. Separation was carried out on a Zorbax SB- C18 analytical column, using asmobile phase a mixture of 75:25 = di-natrium-hydrogenphosphat solution 6 g/1000 ml (pH = 8.5 : methanol.The detection wavelength was set at: 254 nm Calibration graphs were linear with very good correlationcoefficients in the concentration range from 0.320 to 1.5μg /mL. The limits of quantification (LOQ for thesulfonamides were in the range of 6.6–0.34 μg /kg. The recovery for spiked chicken muscle with 50–150 μg/kg ranged more than 70%. The relative standard deviation (Reds of the sulfonamides for six measurementsat 50 go/kg, 100 μg /kg and 150 μg /kg was less then 15%.The applicability of the method to the analysis of chicken muscle tissue was

  14. Utilization of air pollution control residues for the stabilization/solidification of trace element contaminated soil.

    Science.gov (United States)

    Travar, I; Kihl, A; Kumpiene, J

    2015-12-01

    The aim of this study was to evaluate the stabilization/solidification (S/S) of trace element-contaminated soil using air pollution control residues (APCRs) prior to disposal in landfill sites. Two soil samples (with low and moderate concentrations of organic matter) were stabilized using three APCRs that originated from the incineration of municipal solid waste, bio-fuels and a mixture of coal and crushed olive kernels. Two APCR/soil mixtures were tested: 30% APCR/70% soil and 50% APCR/50% soil. A batch leaching test was used to study immobilization of As and co-occurring metals Cr, Cu, Pb and Zn. Solidification was evaluated by measuring the unconfined compression strength (UCS). Leaching of As was reduced by 39-93% in APCR/soil mixtures and decreased with increased amounts of added APCR. Immobilization of As positively correlated with the amount of Ca in the APCR and negatively with the amount of soil organic matter. According to geochemical modelling, the precipitation of calcium arsenate (Ca3(AsO4)2/4H2O) and incorporation of As in ettringite (Ca6Al2(SO4)3(OH)12 · 26H2O) in soil/APCR mixtures might explain the reduced leaching of As. A negative effect of the treatment was an increased leaching of Cu, Cr and dissolved organic carbon. Solidification of APCR/soil was considerably weakened by soil organic matter.

  15. Recent Advances and Uses of Monolithic Columns for the Analysis of Residues and Contaminants in Food

    Directory of Open Access Journals (Sweden)

    Mónica Díaz-Bao

    2015-02-01

    Full Text Available Monolithic columns are gaining interest as excellent substitutes to conventional particle-packed columns. These columns show higher permeability and lower flow resistance than conventional liquid chromatography columns, providing high-throughput performance, resolution and separation in short run times. Monoliths possess also great potential for the clean-up and preparation of complex mixtures. In situ polymerization inside appropriate supports allows the development of several microextraction formats, such as in-tube solid-phase and pipette tip-based extractions. These techniques using porous monoliths offer several advantages, including miniaturization and on-line coupling with analytical instruments. Additionally, monoliths are ideal support media for imprinting template-specific sites, resulting in the so-called molecularly-imprinted monoliths, with ultra-high selectivity. In this review, time-saving LC columns and preparative applications applied to the analysis of residues and contaminants in food in 2010–2014 are described, focusing on recent improvements in design and with emphasis in automated on-line systems and innovative materials and formats.

  16. [Compositions and residual properties of petroleum hydrocarbon in contaminated soil of the oilfields].

    Science.gov (United States)

    Hu, Di; Li, Chuan; Dong, Qian-Qian; Li, Li-Ming; Li, Guang-He

    2014-01-01

    The aims of this study were to determine the compositions and residual properties of petroleum hydrocarbon in soil, as well as to identify the source and weathering degree of the pollution. A total of 5 producing wells in Gudao and Hekou oil producing region of Shengli oilfields were analyzed. More than 50 individual target compounds including straight-and branched-chain alkanes( n-alkanes, pristine and phytane) and polycyclic aromatic hydrocarbons (PAHs) in soil samples and crude oil were determined by gas chromatography-mass spectrometry (GC-MS). The percentages of chain alkanes and PAHs in total solvent extractable matters(TSEM) of soil samples were both much lower than those in the crude oil samples. The compositions of petroleum hydrocarbon in soil samples differed from those in crude oil, which indicated the n-alkanes with carbon numbers contaminated soils, the relationship between the index and petroleum hydrocarbon compounds was analyzed using principal component analysis (PCA). The results showed that the n-alkanes with carbon numbers > 33 and the PAHs with rings between 3 and 5 were much harder to degrade. PCA of 4 indexes for source identification revealed more than 50% of the soil samples were polluted by crude oil, which needs more attention during remediation.

  17. Contaminant transport in the Snake River Plain Aquifer: Phase 1, Part 1: Simple analytical model of individual plumes

    International Nuclear Information System (INIS)

    Rood, A.S.; Arnett, R.C.; Barraclough, J.T.

    1989-05-01

    A preliminary, semi-quantitative assessment of the migration of INEL effluents in the Snake River Plain Aquifer (SRPA) was performed. This study focused on past tritium, 129 I, and 90 Sr effluents from the Idaho Chemical Processing Plant (ICPP) and Test Reactor Area (TRA) and carbon tetrachloride from the Radioactive Waste Management Complex (RWMC). The disposal ponds at TRA and the ICPP injection well were the primary means of liquid radioactive waste discharge from the ICPP and TRA. Drums containing solidified chlorinated solvents disposed of at the RWMC were the primary source of carbon tetrachloride. Water samples taken from wells located in the SRPA show detectable quantities of the four contaminants. The predicted radionuclide concentrations exceed drinking water limits in limited areas within the INEL boundaries. Without planned remedial action, carbon tetrachloride is predicted to exceed drinking water limits beyond the site boundaries near the middle of the next century. 16 refs., 23 figs., 3 tabs

  18. Contaminant Release from Residual Waste in Closed Single-Shell Tanks and Other Waste Forms Associated with the Tanks

    International Nuclear Information System (INIS)

    Deutsch, William J.

    2008-01-01

    This chapter describes the release of contaminants from the various waste forms that are anticipated to be associated with closure of the single-shell tanks. These waste forms include residual sludge or saltcake that will remain in the tanks after waste retrieval. Other waste forms include engineered glass and cementitious materials as well as contaminated soil impacted by previous tank leaks. This chapter also describes laboratory testing to quantify contaminant release and how the release data are used in performance/risk assessments for the tank waste management units and the onsite waste disposal facilities. The chapter ends with a discussion of the surprises and lessons learned to date from the testing of waste materials and the development of contaminant release models

  19. A tiered analytical protocol for the characterization of heavy oil residues at petroleum-contaminated hazardous waste sites

    International Nuclear Information System (INIS)

    Pollard, S.J.T.; Kenefick, S.L.; Hrudey, S.E.; Fuhr, B.J.; Holloway, L.R.; Rawluk, M.

    1994-01-01

    The analysis of hydrocarbon-contaminated soils from abandoned refinery sites in Alberta, Canada is used to illustrate a tiered analytical approach to the characterization of complex hydrocarbon wastes. Soil extracts isolated from heavy oil- and creosote-contaminated sites were characterized by thin layer chromatography with flame ionization detection (TLC-FID), ultraviolet fluorescence, simulated distillation (GC-SIMDIS) and chemical ionization GC-MS analysis. The combined screening and detailed analytical methods provided information essential to remedial technology selection including the extent of contamination, the class composition of soil extracts, the distillation profile of component classes and the distribution of individual class components within various waste fractions. Residual contamination was characteristic of heavy, degraded oils, consistent with documented site operations and length of hydrocarbon exposure at the soil surface

  20. Effects of rapeseed residue on lead and cadmium availability and uptake by rice plants in heavy metal contaminated paddy soil.

    Science.gov (United States)

    Ok, Yong Sik; Usman, Adel R A; Lee, Sang Soo; Abd El-Azeem, Samy A M; Choi, Bongsu; Hashimoto, Yohey; Yang, Jae E

    2011-10-01

    Rapeseed (Brassica napus L.) has been cultivated for biodiesel production worldwide. Winter rapeseed is commonly grown in the southern part of Korea under a rice-rapeseed double cropping system. In this study, a greenhouse pot experiment was conducted to assess the effects of rapeseed residue applied as a green manure alone or in combinations with mineral N fertilizer on Cd and Pb speciation in the contaminated paddy soil and their availability to rice plant (Oryza sativa L.). The changes in soil chemical and biological properties in response to the addition of rapeseed residue were also evaluated. Specifically, the following four treatments were evaluated: 100% mineral N fertilizer (N100) as a control, 70% mineral N fertilizer+rapeseed residue (N70+R), 30% mineral N fertilizer+rapeseed residue (N30+R) and rapeseed residue alone (R). The electrical conductivity and exchangeable cations of the rice paddy soil subjected to the R treatment or in combinations with mineral N fertilizer treatment, N70+R and N30+R, were higher than those in soils subjected to the N100 treatment. However, the soil pH value with the R treatment (pH 6.3) was lower than that with N100 treatment (pH 6.9). Use of rapeseed residue as a green manure led to an increase in soil organic matter (SOM) and enhanced the microbial populations in the soil. Sequential extraction also revealed that the addition of rapeseed residue decreased the easily accessible fraction of Cd by 5-14% and Pb by 30-39% through the transformation into less accessible fractions, thereby reducing metal availability to the rice plant. Overall, the incorporation of rapeseed residue into the metal contaminated rice paddy soils may sustain SOM, improve the soil chemical and biological properties, and decrease the heavy metal phytoavailability. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Long-term groundwater contamination after source removal—The role of sorbed carbon and nitrogen on the rate of reoxygenation of a treated-wastewater plume on Cape Cod, MA, USA

    Science.gov (United States)

    Smith, Richard L.; Repert, Deborah A.; Barber, Larry B.; LeBlanc, Denis R.

    2013-01-01

    The consequences of groundwater contamination can remain long after a contaminant source has been removed. Documentation of natural aquifer recoveries and empirical tools to predict recovery time frames and associated geochemical changes are generally lacking. This study characterized the long-term natural attenuation of a groundwater contaminant plume in a sand and gravel aquifer on Cape Cod, Massachusetts, after the removal of the treated-wastewater source. Although concentrations of dissolved organic carbon (DOC) and other soluble constituents have decreased substantially in the 15 years since the source was removed, the core of the plume remains anoxic and has sharp redox gradients and elevated concentrations of nitrate and ammonium. Aquifer sediment was collected from near the former disposal site at several points in time and space along a 0.5-km-long transect extending downgradient from the disposal site and analyses of the sediment was correlated with changes in plume composition. Total sediment carbon content was generally low (rates in laboratory incubations, which ranged from 11.6 to 44.7 nmol (g dry wt)− 1 day− 1. Total water extractable organic carbon was groundwater velocity. This suggests that the total sorbed carbon pool is large relative to the rate of oxygen entrainment and will be impacting groundwater geochemistry for many decades. This has implications for long-term oxidation of reduced constituents, such as ammonium, that are being transported downgradient away from the infiltration beds toward surface and coastal discharge zones.

  2. Attenuation of contaminant plumes in homogeneous aquifers: Sensitivity to source function at moderate to large peclet numbers

    International Nuclear Information System (INIS)

    Selander, W.N.; Lane, F.E.; Rowat, J.H.

    1995-05-01

    A groundwater mass transfer calculation is an essential part of the performance assessment for radioactive waste disposal facilities. AECL's IRUS (Intrusion Resistant Underground Structure) facility, which is designed for the near-surface disposal of low-level radioactive waste (LLRW), is to be situated in the sandy overburden at AECL's Chalk River Laboratories. Flow in the sandy aquifers at the proposed IRUS site is relatively homogeneous and advection-dominated (large Peclet numbers). Mass transfer along the mean direction of flow from the IRUS site may be described using the one-dimensional advection-dispersion equation, for which a Green's function representation of downstream radionuclide flux is convenient. This report shows that in advection-dominated aquifers, dispersive attenuation of initial contaminant releases depends principally on two time scales: the source duration and the pulse breakthrough time. Numerical investigation shows further that the maximum downstream flux or concentration depends on these time scales in a simple characteristic way that is minimally sensitive to the shape of the initial source pulse. (author). 11 refs., 2 tabs., 3 figs

  3. Residual risk of bacterial contamination of platelets: six years of experience with sterility testing.

    Science.gov (United States)

    Ramirez-Arcos, Sandra; DiFranco, Caesar; McIntyre, Terri; Goldman, Mindy

    2017-09-01

    Canadian Blood Services screens 100% of platelet concentrates (PCs) for bacterial contamination with the BacT/ALERT system. Quality-control sterility testing of 1% (≥10 units) of outdated PCs is performed monthly. Data from routine screening, quality-control testing, and septic reactions obtained from 2010 to 2016 are presented herein. In total, 601,988 buffy coat PC pools and 186,737 apheresis PCs were routinely screened with aerobic cultures over 6 years. Outdate quality-control testing of 8535 buffy coat and 8498 apheresis PCs was performed using aerobic and anaerobic cultures during the same period. Results were classified as "true-positives" when the same bacterium was isolated in initial and confirmatory cultures or "false-negatives" when bacteria were missed in early screening and were captured during quality-control sterility testing or through investigation of sepsis cases. During routine screening, the true-positive rates between buffy coat (0.94 per 10,000) and apheresis (0.96 per 10,000) PCs were similar (p = 0.9473). Seventy-five bacteria isolated during PC screening included Gram-positive and Gram-negative organisms. Six false-negative septic reactions were reported that implicated coagulase-negative staphylococci (n = 3) and Staphylococcus aureus (n = 3) for approximate rates of 1 per 100,000 transfusion reactions and 1 per 500,000 fatalities. During quality-control testing, the false-negative rates between buffy coat (8 per 10,000) and apheresis (9 per 10,000) PCs were similar (p = 0.7897). All 15 quality-control isolates were Gram-positive bacteria. The current bacterial screening protocol is efficacious for identifying Gram-negative bacteria. However, the high proportion of Gram-positive organisms detected on outdate quality-control testing and septic transfusion events demonstrates a residual safety risk that merits further intervention. © 2017 AABB.

  4. Estimating the Exposure of Coral Reefs and Seagrass Meadows to Land-Sourced Contaminants in River Flood Plumes of the Great Barrier Reef: Validating a Simple Satellite Risk Framework with Environmental Data

    Directory of Open Access Journals (Sweden)

    Caroline Petus

    2016-03-01

    Full Text Available River runoff and associated flood plumes (hereafter river plumes are a major source of land-sourced contaminants to the marine environment, and are a significant threat to coastal and marine ecosystems worldwide. Remote sensing monitoring products have been developed to map the spatial extent, composition and frequency of occurrence of river plumes in the Great Barrier Reef (GBR, Australia. There is, however, a need to incorporate these monitoring products into Risk Assessment Frameworks as management decision tools. A simple Satellite Risk Framework has been recently proposed to generate maps of potential risk to seagrass and coral reef ecosystems in the GBR focusing on the Austral tropical wet season. This framework was based on a “magnitude × likelihood” risk management approach and GBR plume water types mapped from satellite imagery. The GBR plume water types (so called “Primary” for the inshore plume waters, “Secondary” for the midshelf-plume waters and “Tertiary” for the offshore plume waters represent distinct concentrations and combinations of land-sourced and marine contaminants. The current study aimed to test and refine the methods of the Satellite Risk Framework. It compared predicted pollutant concentrations in plume water types (multi-annual average from 2005–2014 to published ecological thresholds, and combined this information with similarly long-term measures of seagrass and coral ecosystem health. The Satellite Risk Framework and newly-introduced multi-annual risk scores were successful in demonstrating where water conditions were, on average, correlated to adverse biological responses. Seagrass meadow abundance (multi-annual change in % cover was negatively correlated to the multi-annual risk score at the site level (R2 = 0.47, p < 0.05. Relationships between multi-annual risk scores and multi-annual changes in proportional macroalgae cover (as an index for coral reef health were more complex (R2 = 0.04, p

  5. Pyrolysis and reutilization of plant residues after phytoremediation of heavy metals contaminated sediments: For heavy metals stabilization and dye adsorption.

    Science.gov (United States)

    Gong, Xiaomin; Huang, Danlian; Liu, Yunguo; Zeng, Guangming; Wang, Rongzhong; Wei, Jingjing; Huang, Chao; Xu, Piao; Wan, Jia; Zhang, Chen

    2018-04-01

    This study aimed to investigate the effect of pyrolysis on the stabilization of heavy metals in plant residues obtained after phytoremediation. Ramie residues, being collected after phytoremediation of metal contaminated sediments, were pyrolyzed at different temperatures (300-700 °C). Results indicated that pyrolysis was effective in the stabilization of Cd, Cr, Zn, Cu, and Pb in ramie residues by converting the acid-soluble fraction of metals into residual form and decreasing the TCLP-leachable metal contents. Meanwhile, the reutilization potential of using the pyrolysis products generated from ramie residues obtained after phytoremediation as sorbents was investigated. Adsorption experiments results revealed that the pyrolysis products presented excellent ability to adsorb methylene blue (MB) with a maximum adsorption capacity of 259.27 mg/g. This study demonstrated that pyrolysis could be used as an efficient alternative method for stabilizing heavy metals in plant residues obtained after phytoremediation, and their pyrolysis products could be reutilized for dye adsorption. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Lead speciation in 0.1N HCl-extracted residue of analog of Pb-contaminated soil

    International Nuclear Information System (INIS)

    Wei Yuling; Yang, Y.-W.; Lee, J.-F.

    2005-01-01

    The heavy metal in-taken by plants from contaminated soils is usually assessed by extraction with 0.1N HCl. This study characterized the chemical form of lead in the solid residue of 0.1N HCl-extracted Pb-contaminated kaolin. The results indicate that most lead in the 0.1N HCl-extracted residue of the Pb(NO 3 ) 2 -contaminated kaolin dried at 105 deg C is mainly in form of PbCl 2 . For other lead-containing kaolin sample heated at 900 deg C, the XAS analysis also shows that majority of the lead compound was converted into PbCl 2 precipitate that remained in the solid residue during the 0.1N HCl extraction. Because PbCl 2 is only slightly soluble in dilute acids or water, it is suggested that using 0.1N HCl liquid as an extracting reagent to represent the heavy metal uptake by plants might actually underestimate the uptake

  7. Flow of microemulsion through soil columns contaminated with asphaltic residue; Fluxo de microemulsoes atraves do solo contaminado com residuos asfalticos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Marcia C.K.; Oliveira, Jose F. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE); Oliveira, Roberto C.G.; Gonzalez, Gazpar [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2004-07-01

    Nowadays, soil contamination with nonaqueous phase liquids (NAPLs) such as petroleum hydrocarbons is a major environmental problem. Significant efforts have been devoted to the development of processes to remediate sites contaminated with NAPLs. Unfortunately, most of the developed processes proved to be inefficient to remove the organic heavy fraction present in the NAPLs. Nevertheless, in our preliminary bench scale tests it was observed that, due to their high solubilization capacity and stability, microemulsions are able to remove organic heavy fractions like asphaltenes and resins, typically present in crude oils. The present work was dimensioned to evaluate, under up-flow condition, the performance of different microemulsions specially designed to remove asphaltenes fractions from soils using a column test set-up. The contaminant residual concentration was quantified by UV spectroscopy and the microemulsion efficiency determined using mass balance. The results showed that the microemulsions tested have a high capacity for removing asphaltenes fractions from contaminated soils. It was also observed that the predominant removal mechanism, solubilization or mobilization, depends essentially on the microemulsion's chemical formulation. Finally it was verified that microemulsion's formulations based on natural solvents compounds are also efficient for removing asphaltic residues. (author)

  8. Spatial distribution of soil contamination by 137Cs and 239,240Pu in the village of Dolon near the Semipalatinsk nuclear test site: new information on traces of the radioactive plume from the 29 August 1949 nuclear test.

    Science.gov (United States)

    Yamamoto, M; Tomita, J; Sakaguchi, A; Imanaka, T; Fukutani, S; Endo, S; Tanaka, K; Hoshi, M; Gusev, B I; Apsalikov, A N

    2008-04-01

    The village of Dolon located about 60 km northeast from the border of the Semipalatinsk Nuclear Test Site in Kazakhstan is one of the most affected inhabited settlements as a result of nuclear tests by the former USSR. Radioactive contamination in Dolon was mainly caused by the first USSR nuclear test on 29 August 1949. As part of the efforts to reconstruct the radiation dose in Dolon, Cs and Pu in soil samples collected from 26 locations in the vicinity of and within the village were measured to determine the width and position of the center-axis of the radioactive plume that passed over the village from the 29 August 1949 nuclear test. Measured soil inventories of Cs and Pu were plotted as a function of the distance from the supposed center-axis of the plume. A clear shape similar to a Gaussian function was observed in their spatial distributions with each maximum around a center-axis. It was suggested that the plume width that contaminated Dolon was at most 10 km and the real center-axis of the radioactive plume passed 0.7-0.9 km north of the supposed centerline. A peak-like shape with the maximum near the center-axis was also observed in the spatial distribution of the Pu/Cs activity ratio, which may reflect the fractionation effect between Pu and Cs during the deposition process. These results support the recently reported results. The data obtained here will provide useful information on the efforts to estimate radiation dose in Dolon as reliably as possible. Health Phys. 94(4):328-337; 2008.

  9. Biogeochemistry of landfill leachate plumes

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Kjeldsen, Peter; Bjerg, Poul Løgstrup

    2001-01-01

    are relatively narrow and do not in terms of width exceed the width of the landfill. The concept of redox zones being present in the plume has been confirmed by the reported composition of the leachate contaminated groundwater at several landfills and constitutes an important framework for understanding...... the behavior of the contaminants in the plume as the leachate migrates away from the landfill. Diverse microbial communities have been identified in leachate plumes and are believed to be responsible for the redox processes. Dissolved organic C in the leachate, although it appears to be only slowly degradable...... to be subject to anaerobic oxidation, but the mechanisms are not yet understood. Heavy metals do not seem to constitute a significant pollution problem at landfills, partly because the heavy metal concentrations in the leachate often are low, and partly because of strong attenuation by sorption...

  10. JUSTIFICATION FOR THE RADIOLOGICAL CRITERIA FOR THE USE OF AREAS WITH RESIDUAL RADIOACTIVE CONTAMINATION BASED ON THE DOSE APPROACH

    Directory of Open Access Journals (Sweden)

    V. Yu. Golikov

    2017-01-01

    Full Text Available The article presents a methodology for assessing the radiological criteria for the use of the territory (a land plot with buildings with residual radioactive contamination from the so-called “green area”, i.e., complete release from radiation control until a number of restrictions are imposed on the use of the territory. In accordance with the further use of the territory, a range of scenarios and pathways for the exposure of the population was considered. A set of models and their parameters, corresponding to the number of the considered pathways of exposure, was defined. Assuming a uniform distribution of a radionuclide with a unit concentration in the source zone, the distribution of effective doses for the population living in the territory with the residual radioactive contamination for different irradiation scenarios was calculated by stochastic modeling, 95% of the quantile of which was attributed to the dose in the representatives of the critical population group. Next, the value of radiological criteria, depending on the implemented scenario, was determined as the ratio of the dose constraint EL = 0,3 mSv/yr and 95% quantile in the distribution of the effective dose from a unit contamination. The numerical values of radiological criteria for the presence of radionuclides in the soil are presented, both for the radiation scenarios that correspond to the permanent residence of the population in the contaminated territory and for recreational use. A further consideration is given to the so-called worker scenario, which corresponds to the limited time spent on the contaminated territory and the simultaneous effects of radionuclides contained both in the soil and in the construction of the buildings. A comparison of the results of the own calculations with the data of other authors was carried out.

  11. Enhanced bioremediation of PAH-contaminated soil by immobilized bacteria with plant residue and biochar as carriers

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Baoliang; Yuan, Miaoxin; Qian, Linbo [Zhejiang Univ., Hangzhou (China). Dept. of Environmental Science; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou (China)

    2012-10-15

    Polycyclic aromatic hydrocarbons (PAHs) are largely accumulated in soils in China. The immobilized-microorganism technique (IMT) is a potential approach for abating soil contamination with PAHs. However, few studies about the application of IMT to contaminated soil remediation were reported. Due to recalcitrance to decomposition, biochar application to soil may enhance soil carbon sequestration, but few studies on the application of biochars to remediation of contaminated soil were reported. In this study, we illustrated enhanced bioremediation of soil having a long history of PAH contamination by IMT using plant residues and biochars as carriers. Two PAH-degrading bacteria, Pseudomonas putida and an unidentified indigenous bacterium, were selected for IMT. The extractability and biodegradation of 15 PAHs in solution and an actual PAH-contaminated soil amended with immobilized-bacteria materials were investigated under different incubation periods. The effects of carriers and the molecular weight of PAHs on bioremediation efficiency were determined to illustrate their different bio-dissipation mechanisms of PAHs in soil. The IMT can considerably enhance the removal of PAHs. Carriers impose different effects on PAH bio-dissipation by amended soil with immobilized-bacteria, which can directly degrade the carrier-associated PAHs. The removal of PAHs from soil depended on PAH molecular weight and carrier types. Enhanced bio-dissipation by IMT was much stronger for 4- and 5-ring PAHs than for 3- and 6-ring ones in soil. Only P400 biochar-immobilized bacteria enhanced bio-dissipation of all PAHs in contaminated soil after a 90-day incubation. Biochar can promote bioremediation of contaminated soil as microbial carriers of IMT. It is vital to select an appropriate biochar as an immobilized carrier to stimulate biodegradation. It is feasible to use adsorption carriers with high sorptive capabilities to concentrate PAHs as well as microorganisms and thereby enhance

  12. Measurement of residual radioactive surface contamination by 2-D laser heated TLD

    International Nuclear Information System (INIS)

    Jones, S.C.

    1997-06-01

    The feasibility of applying and adapting a two-dimensional laser heated thermoluminescence dosimetry system to the problem of surveying for radioactive surface contamination was studied. The system consists of a CO 2 laser-based reader and monolithic arrays of thin dosimeter elements. The arrays consist of 10,201 thermoluminescent phosphor elements of 40 micron thickness, covering a 900 cm 2 area. Array substrates are 125 micron thick polyimide sheets, enabling them to easily conform to regular surface shapes, especially for survey of surfaces that are inaccessible for standard survey instruments. The passive, integrating radiation detectors are sensitive to alpha and beta radiation at contamination levels below release guideline limits. Required contact times with potentially contaminated surfaces are under one hour to achieve detection of transuranic alpha emission at 100 dpm/100 cm 2 . Positional information obtained from array evaluation is useful for locating contamination zones. Unique capabilities of this system for survey of sites, facilities and material include measurement inside pipes and other geometrical configurations that prevent standard surveys, and below-surface measurement of alpha and beta emitters in contaminated soils. These applications imply a reduction of material that must be classified as radioactive waste by virtue of its possibility of contamination, and cost savings in soil sampling at contaminated sites

  13. Contamination Detection and Mitigation Strategies for Unsymmetric Dimethylhydrazine/Nitrogen Tetroxide Non-Combustion Product Residues

    Science.gov (United States)

    Greene, Benjamin; Buchanan, Vanessa D.; Baker, David L.

    2006-01-01

    Dimethylamine and nitrite, which are non-combustion reaction products of unsymmetrical dimethylhydrazine (UDMH) and nitrogen tetroxide (NTO) propellants, can contaminate spacesuits during extra-vehicular activity (EVA) operations. They can react with water in the International Space Station (ISS) airlock to form N-nitrosodimethylamine (NDMA), a carcinogen. Detection methods for assessing nitrite and dimethylamine contamination were investigated. The methods are based on color-forming reactions in which intensity of color is proportional to concentration. A concept color detection kit using a commercially available presumptive field test for methamphetamine coupled with nitrite test strips was developed and used to detect dimethylamine and nitrite. Contamination mitigation strategies were also developed.

  14. Progress on immobilisation of plutonium residues and shredded plutonium contaminated materials in cement

    International Nuclear Information System (INIS)

    Landles, A.J.; Awmack, A.F.; Baxter, W.

    1987-03-01

    Laboratory scale experiments have been carried out to study the feasibility of encapsulating plutonium contaminated materials in cement. A proposed grout of a 3:1 PFA/OPC mixture has been tested and some product evaluation carried out. (author)

  15. Evaluation of residual uranium contamination in the dirt floor of an abandoned metal rolling mill.

    Science.gov (United States)

    Glassford, Eric; Spitz, Henry; Lobaugh, Megan; Spitler, Grant; Succop, Paul; Rice, Carol

    2013-02-01

    A single, large, bulk sample of uranium-contaminated material from the dirt floor of an abandoned metal rolling mill was separated into different types and sizes of aliquots to simulate samples that would be collected during site remediation. The facility rolled approximately 11,000 tons of hot-forged ingots of uranium metal approximately 60 y ago, and it has not been used since that time. Thirty small mass (≈ 0.7 g) and 15 large mass (≈ 70 g) samples were prepared from the heterogeneously contaminated bulk material to determine how measurements of the uranium contamination vary with sample size. Aliquots of bulk material were also resuspended in an exposure chamber to produce six samples of respirable particles that were obtained using a cascade impactor. Samples of removable surface contamination were collected by wiping 100 cm of the interior surfaces of the exposure chamber with 47-mm-diameter fiber filters. Uranium contamination in each of the samples was measured directly using high-resolution gamma ray spectrometry. As expected, results for isotopic uranium (i.e., U and U) measured with the large-mass and small-mass samples are significantly different (p 0.05) from results for the large- or small-mass samples. Large-mass samples are more reliable for characterizing heterogeneously distributed radiological contamination than small-mass samples since they exhibit the least variation compared to the mean. Thus, samples should be sufficiently large in mass to insure that the results are truly representative of the heterogeneously distributed uranium contamination present at the facility. Monitoring exposure of workers and the public as a result of uranium contamination resuspended during site remediation should be evaluated using samples of sufficient size and type to accommodate the heterogeneous distribution of uranium in the bulk material.

  16. Residual endotoxin contaminations in recombinant proteins are sufficient to activate human CD1c+ dendritic cells.

    Directory of Open Access Journals (Sweden)

    Harald Schwarz

    Full Text Available Many commercially available recombinant proteins are produced in Escherichia coli, and most suppliers guarantee contamination levels of less than 1 endotoxin unit (EU. When we analysed commercially available proteins for their endotoxin content, we found contamination levels in the same range as generally stated in the data sheets, but also some that were higher. To analyse whether these low levels of contamination have an effect on immune cells, we stimulated the monocytic cell line THP-1, primary human monocytes, in vitro differentiated human monocyte-derived dendritic cells, and primary human CD1c+ dendritic cells (DCs with very low concentrations of lipopolysaccharide (LPS; ranging from 0.002-2 ng/ml. We show that CD1c+ DCs especially can be activated by minimal amounts of LPS, equivalent to the levels of endotoxin contamination we detected in some commercially available proteins. Notably, the enhanced endotoxin sensitivity of CD1c+ DCs was closely correlated with high CD14 expression levels observed in CD1c+ DCs that had been maintained in cell culture medium for 24 hours. When working with cells that are particularly sensitive to LPS, even low endotoxin contamination may generate erroneous data. We therefore recommend that recombinant proteins be thoroughly screened for endotoxin contamination using the limulus amebocyte lysate test, fluorescence-based assays, or a luciferase based NF-κB reporter assay involving highly LPS-sensitive cells overexpressing TLR4, MD-2 and CD14.

  17. Allowable residual contamination levels of radionuclides in soil from pathway analysis

    International Nuclear Information System (INIS)

    Nyquist, J.E.; Baes, C.F. III

    1987-01-01

    The Remedial Action Program (RAP) at Oak Ridge National Laboratory will include well drilling, facility upgrades, and other waste management operations likely to involve soils contaminated with radionuclides. A preliminary protocol and generalized criteria for handling contaminated soils is needed to coordinate and plan RAP activities, but there exists only limited information on contaminate nature and distribution at ORNL RAP sites. Furthermore, projections of long-term decommissioning and closure options for these sites are preliminary. They have adapted a pathway analysis model, DECOM, to quantify risks to human health from radionuclides in soil and used it to outline preliminary criteria for determining the fate of contaminated soil produced during RAP activities. They assumed that the site could be available for unrestricted use immediately upon decontamination. The pathways considered are consumption of food grown on the contaminated soil, including direct ingestion of soil from poorly washed vegetables, direct radiation from the ground surface, inhalation of resuspended radioactive soil, and drinking water from a well drilled through or near the contaminated soil. We will discuss the assumptions and simplifications implicit in DECOM, the site-specific data required, and the results of initial calculations for the Oak Ridge Reservation

  18. European sites contaminated by residues from the ore extracting and processing industries

    International Nuclear Information System (INIS)

    Vandenhove, H.

    2000-01-01

    Activities linked with the ore extraction and processing industries may lead to enhanced levels of naturally occurring radionuclides (NORs) in products, by-products and waste and at the installations and in the surroundings of the facility. In the framework of the EC-DGXI CARE project (Common Approach for REstoration of contaminated sites) nine important categories of industries were identified and discussions were summarized on the industrial processes and the levels of NORs in parent material, waste and by-products. The most contaminating industries are uranium mining and milling, metal mining and smelting and the phosphate industry. Radionuclide levels in products and/or waste products from the oil and gas extraction industry and of the rare earth, zirconium and ceramics industries may be particularly elevated, but waste streams are limited. The impact on the public from coal mining and power production from coal is commonly considered low. No typical values are available for contaminant levels in materials, buildings and surroundings of radium extraction and luminizing plants, nor for thorium extraction and processing plants. An attempt to give an overview of sites in Europe contaminated with NORs, with emphasis on past practices, was only partly successful since information was often limited or unavailable. The most prominent case of environmental contamination due to mining and processing activities (uranium, metal and coal mining) is in eastern Germany. (author)

  19. Insect Residue Contamination on Wing Leading Edge Surfaces: A Materials Investigation for Mitigation

    Science.gov (United States)

    Lorenzi, Tyler M.; Wohl, Christopher J.; Penner, Ronald K.; Smith, Joseph G.; Siochi, Emilie J.

    2011-01-01

    Flight tests have shown that residue from insect strikes on aircraft wing leading edge surfaces may induce localized transition of laminar to turbulent flow. The highest density of insect populations have been observed between ground level and 153 m during light winds (2.6 -- 5.1 m/s), high humidity, and temperatures from 21 -- 29 C. At a critical residue height, dependent on the airfoil and Reynolds number, boundary layer transition from laminar to turbulent results in increased drag and fuel consumption. Although this represents a minimal increase in fuel burn for conventional transport aircraft, future aircraft designs will rely on maintaining laminar flow across a larger portion of wing surfaces to reduce fuel burn during cruise. Thus, insect residue adhesion mitigation is most critical during takeoff and initial climb to maintain laminar flow in fuel-efficient aircraft configurations. Several exterior treatments investigated to mitigate insect residue buildup (e.g., paper, scrapers, surfactants, flexible surfaces) have shown potential; however, implementation has proven to be impractical. Current research is focused on evaluation of wing leading edge surface coatings that may reduce insect residue adhesion. Initial work under NASA's Environmentally Responsible Aviation Program focused on evaluation of several commercially available products (commercial off-the-shelf, COTS), polymers, and substituted alkoxy silanes that were applied to aluminum (Al) substrates. Surface energies of these coatings were determined from contact angle data and were correlated to residual insect excrescence on coated aluminum substrates using a custom-built "bug gun." Quantification of insect excrescence surface coverage was evaluated by a series of digital photographic image processing techniques.

  20. Laboratory evaluation of particle size, food contamination, and residual efficacy of pyrethrin + methoprene aerosol

    Science.gov (United States)

    A series of tests were conducted to determine residual efficacy of pyrethrin+methoprene aerosol to manage larvae of selected stored product insects. Efficacy was assessed through emergence of morphologically-normal adults and through a quantitative developmental index with values ranging from 1, for...

  1. Characterization of residual radionuclide contamination within and around commercial nuclear power plants

    International Nuclear Information System (INIS)

    Robertson, D.E.; Abel, K.H.; Thomas, C.W.; Lepel, E.A.; Evans, J.C.; Thomas, W.V.; Carrick, L.C.; Leale, M.W.

    1985-07-01

    To provide a statistically valid data base for the residual radionuclide inventories in nuclear power stations, Pacific Northwest Laboratory (PNL) was contracted to conduct an extensive sampling and measurements program at a number of nuclear power plants. This paper summarizes the results of the radionuclide characterization studies conducted at seven nuclear power stations from a decommissioning assessment viewpoint

  2. De-contamination of pesticide residues in food by ionizing radiation

    International Nuclear Information System (INIS)

    Basfar, Ahmed A.; Mohamed, Khaled A.; Al-Saqer, Omar A.

    2012-01-01

    The role of gamma irradiation on removal of pesticides in aqueous solutions or in vegetables and fruits was investigated. Radiation - induced decontamination of pesticides is generally greater in aqueous solutions than in selected vegetables and fruits. Residues of malathion (0.5 ppm in potatoes, 8 ppm in onions and dates), pirimiphos-methyl (1 ppm in onions and grapes) and cypermethrin (0.05 ppm in potatoes and 0.1 ppm in onions) were not reduced to below maximum residue limits (MRLs) for irradiation doses up to 1 kGy. The same trend was observed when irradiation was performed for grapes fortified with malathion (8 ppm) and cypermethrin (2 ppm) for absorbed doses up to 2 kGy. Ionizing radiation reduced the residues of pirimiphos-methyl (0.05 ppm in potatoes at1 kGy, 1 ppm in grapes at 2 kGy and 0.1 ppm in dates at1 kGy), malathion (8 ppm in grapes at 7 kGy) and cypermethrin (2 ppm in grapes at 7 kGy) to below maximum residue limits (MRLs). - Highlights: ► The role of irradiation on removal of pesticides in aqueous solutions or in food products was investigated. ► Radiation-induced removal of pesticides is generally greater in aqueous solutions than in food products. ► Radiation can reduce the pirimiphos-methyl in potatoes, grapes and dates to below MRLs. ► Radiation can reduce the malathion and cypermethrin in grapes to below MRLs. ► Radiation is used for dual objectives of reducing pesticide residues and improving food safety.

  3. Contamination profile of aflatoxin M1 residues in milk supply chain of Sindh, Pakistan

    Directory of Open Access Journals (Sweden)

    Sana Jawaid

    2015-01-01

    Full Text Available Aflatoxin M1 (AFM1 is a potent carcinogen, teratogen and mutagen found in the milk when lactating animals consume feed contaminated with aflatoxin B1 (AFB1. In the present study, the contamination of AFM1 was evaluated in the milk supply chain of the province of Sindh, Pakistan. For the broader profiling of targeted toxin, enzyme-linked immunosorbent assay (ELISA was used for the determination of AFM1 in both branded and non-branded milk samples. The results showed that 96.43% of samples (81 out of 84 were contaminated with AFM1 in the range of 0.01–0.76 μg/L. The average contamination level was 0.38 μg/L. The determined values of AFM1 in the collected milk samples were above the standard limit of the European Commission while 70% of the samples exceeded levels established by United States regulations. According to these results, the estimated daily intake of AFM1 for adults was determined as 3.1 ng/kg of body weight per day.

  4. Influence of washing time on residual contamination of carcasses sprayed with lauric acid-potassium hydroxide.

    Science.gov (United States)

    A series of experiments were conducted to examine reductions in bacterial contamination of broiler carcasses washed for various times in a spray cabinet with a 2% lauric acid (LA)-1% potassium hydroxide (KOH) (w/v) solution. Forty eviscerated carcasses and 5 ceca were obtained from the processing l...

  5. Hanford Tanks 241-C-203 and 241-C-204: Residual Waste Contaminant Release Model and Supporting Data

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Schaef, Herbert T.

    2004-10-28

    This report describes the development of release models for key contaminants that are present in residual sludge remaining after closure of Hanford Tanks 241-C-203 (C-203) and 241-C-204 (C-204). The release models were developed from data generated by laboratory characterization and testing of samples from these two tanks. Key results from this work are (1) future releases from the tanks of the primary contaminants of concern (99Tc and 238U) can be represented by relatively simple solubility relationships between infiltrating water and solid phases containing the contaminants; and (2) high percentages of technetium-99 in the sludges (20 wt% in C-203 and 75 wt% in C-204) are not readily water leachable, and, in fact, are very recalcitrant. This is similar to results found in related studies of sludges from Tank AY-102. These release models are being developed to support the tank closure risk assessments performed by CH2M HILL Hanford Group, Inc., for the U.S. Department of Energy.

  6. Hanford Tanks 241-C-203 and 241 C 204: Residual Waste Contaminant Release Model and Supporting Data

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Schaef, Herbert T.

    2007-05-23

    This report was revised in May 2007 to correct 90Sr values in Chapter 3. The changes were made on page 3.9, paragraph two and Table 3.10; page 3.16, last paragraph on the page; and Tables 3.21 and 3.31. The rest of the text remains unchanged from the original report issued in October 2004. This report describes the development of release models for key contaminants that are present in residual sludge remaining after closure of Hanford Tanks 241-C-203 (C-203) and 241-C-204 (C-204). The release models were developed from data generated by laboratory characterization and testing of samples from these two tanks. Key results from this work are (1) future releases from the tanks of the primary contaminants of concern (99Tc and 238U) can be represented by relatively simple solubility relationships between infiltrating water and solid phases containing the contaminants; and (2) high percentages of technetium-99 in the sludges (20 wt% in C-203 and 75 wt% in C-204) are not readily water leachable, and, in fact, are very recalcitrant. This is similar to results found in related studies of sludges from Tank AY-102. These release models are being developed to support the tank closure risk assessments performed by CH2M HILL Hanford Group, Inc., for the U.S. Department of Energy.

  7. Hanford Tanks 241-C-203 and 241-C-204: Residual Waste Contaminant Release Model and Supporting Data

    International Nuclear Information System (INIS)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Schaef, Herbert T.

    2004-01-01

    This report describes the development of release models for key contaminants that are present in residual sludge remaining after closure of Hanford Tanks 241-C-203 (C-203) and 241-C-204 (C-204). The release models were developed from data generated by laboratory characterization and testing of samples from these two tanks. Key results from this work are (1) future releases from the tanks of the primary contaminants of concern (99Tc and 238U) can be represented by relatively simple solubility relationships between infiltrating water and solid phases containing the contaminants; and (2) high percentages of technetium-99 in the sludges (20 wt% in C-203 and 75 wt% in C-204) are not readily water leachable, and, in fact, are very recalcitrant. This is similar to results found in related studies of sludges from Tank AY-102. These release models are being developed to support the tank closure risk assessments performed by CH2M HILL Hanford Group, Inc., for the U.S. Department of Energy

  8. Stabilization of in-tank residuals and external-tank soil contamination: FY 1997 interim report

    International Nuclear Information System (INIS)

    Becker, D.L.

    1997-01-01

    This interim report evaluates various ways to stabilize decommissioned waste tanks and contaminated soils at the AX Tank Farm as part of a preliminary evaluation of end-state options for the Hanford tanks. Five technical areas were considered: (1) emplacement of smart grouts and/or other materials, (2) injection of chemical-getters into contaminated soils surrounding tanks (soil mixing), (3) emplacement of grout barriers under and around the tanks, (4) the use of engineered barriers over the tanks, and (5) the explicit recognition that natural attenuation processes do occur. Research topics are identified in support of key areas of technical uncertainty, in each of the five technical areas. Detailed cost/benefit analyses of the recommended technologies are not provided in this evaluation, performed by Sandia National Laboratories, Albuquerque, New Mexico

  9. Full scale amendment of a contaminated wood impregnation site with iron water treatment residues

    DEFF Research Database (Denmark)

    Nielsen, Sanne Skov; Kjeldsen, Peter; Jakobsen, Rasmus

    2016-01-01

    amendment a 100 m2 test site and a control site (without amendment) were monitored for 14 months. Also soil analysis of Fe to evaluate the degree of soil and Fe-WTR mixing was done. Stabilization with Fe-WTR had a significant effect on leachable contaminants, reducing pore water As by 93%, Cu by 91% and Cr...... by 95% in the upper samplers. Dosage and mixing of Fe-WTR in the soil proved to be difficult in the deeper part of the field, and pore water concentrations of arsenic was generally higher. Despite water logged conditions no increase in dissolved iron or arsenic was observed in the amended soil. Our...... field scale amendment of contaminated soil was overall successful in decreasing leaching of As, Cr and Cu.With minor improvements in the mixing and delivery strategy, this stabilization method is suggested for use in cases, where leaching of Cu, Cr and As constitutes a risk for groundwater...

  10. Phytostabilization of semiarid soils residually contaminated with trace elements using by-products: Sustainability and risks

    Energy Technology Data Exchange (ETDEWEB)

    Perez-de-Mora, Alfredo, E-mail: perezdemora@gmail.com [Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS), CSIC, PO Box 1052, 41080 Sevilla (Spain); Madejon, Paula; Burgos, Pilar; Cabrera, Francisco [Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS), CSIC, PO Box 1052, 41080 Sevilla (Spain); Lepp, Nicholas W. [35, Victoria Road, Formby, Liverpool L37 7DH (United Kingdom); Madejon, Engracia [Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS), CSIC, PO Box 1052, 41080 Sevilla (Spain)

    2011-10-15

    We investigated the efficiency of various by-products (sugarbeet lime, biosolid compost and leonardite), based on single or repeated applications to field plots, on the establishment of a vegetation cover compatible with a stabilization strategy on a multi-element (As, Cd, Cu, Pb and Zn) contaminated soil 4-6 years after initial amendment applications. Results indicate that the need for re-treatment is amendment- and element-dependent; in some cases, a single application may reduce trace element concentrations in above-ground biomass and enhance the establishment of a healthy vegetation cover. Amendment performance as evaluated by % cover, biomass and number of colonizing taxa differs; however, changes in plant community composition are not necessarily amendment-specific. Although the translocation of trace elements to the plant biotic compartment is greater in re-vegetated areas, overall loss of trace elements due to soil erosion and plant uptake is usually smaller compared to that in bare soil. - Highlights: > By-products enhance vegetation dynamics in contaminated semiarid soils. > Depending on the situation single or repeated incorporations may be required. > The structure of the plant community established is not amendment-dependent. > Phytostabilization reduces overall loss of trace elements in semiarid soils. - Phytostabilization using by-products as amendments is a suitable approach for long-term immobilization of various trace elements in semiarid contaminated soils.

  11. Phytostabilization of semiarid soils residually contaminated with trace elements using by-products: Sustainability and risks

    International Nuclear Information System (INIS)

    Perez-de-Mora, Alfredo; Madejon, Paula; Burgos, Pilar; Cabrera, Francisco; Lepp, Nicholas W.; Madejon, Engracia

    2011-01-01

    We investigated the efficiency of various by-products (sugarbeet lime, biosolid compost and leonardite), based on single or repeated applications to field plots, on the establishment of a vegetation cover compatible with a stabilization strategy on a multi-element (As, Cd, Cu, Pb and Zn) contaminated soil 4-6 years after initial amendment applications. Results indicate that the need for re-treatment is amendment- and element-dependent; in some cases, a single application may reduce trace element concentrations in above-ground biomass and enhance the establishment of a healthy vegetation cover. Amendment performance as evaluated by % cover, biomass and number of colonizing taxa differs; however, changes in plant community composition are not necessarily amendment-specific. Although the translocation of trace elements to the plant biotic compartment is greater in re-vegetated areas, overall loss of trace elements due to soil erosion and plant uptake is usually smaller compared to that in bare soil. - Highlights: → By-products enhance vegetation dynamics in contaminated semiarid soils. → Depending on the situation single or repeated incorporations may be required. → The structure of the plant community established is not amendment-dependent. → Phytostabilization reduces overall loss of trace elements in semiarid soils. - Phytostabilization using by-products as amendments is a suitable approach for long-term immobilization of various trace elements in semiarid contaminated soils.

  12. A survey of the Maralinga atomic weapons testing range for residual plutonium contamination

    International Nuclear Information System (INIS)

    Ellis, W.R.

    1979-06-01

    Residual plutonium levels in soil, flora, fauna and the air of the Maralinga (South Australia) Atomic Weapons Testing Range are presented and discussed. It is shown that only on rare occasions (and possibly never) would the plutonium concentration in air from wind resuspended dust exceed the maximum allowable concentration for continuous exposure of the general public. In the case of artificially resuspended dust, this maximum concentration could be exceeded for short periods, but the accompanying dust level would be such that working conditions would be uncomfortable, if not intolerable. Potential hazards from other possible exposure routes are so low that they are of no consequence

  13. Residual effects of metal contamination on the soil quality: a field survey in central Portugal

    Science.gov (United States)

    Kikuchi, Ryunosuke; Gerardo, Romeu

    2017-04-01

    Agriculture is an important source of income and employment. But depletion and degradation of land challenge to producing safe food and other agricultural products to sustain livelihoods and meet the needs of urban populations. When developing or expanding an agricultural area, it becomes essential to access the soil quality. Even if the present source of contamination is not observed, it is a worth subject to evaluate whether or not any negative effects of the post contamination still last. For this purpose, a field survey (2 ha) was carried: a zinc and lead mining site that was abandoned about 50 years ago was researched at Sanguinheiro (40°18'N and 8°21'W) in Central Portugal. The area is characterized by very steep slopes that are confining with a small stream. The obtained results show that (i) the Pb content in the site (165 mg/kg) is higher than that in the background (67.7 mg/kg); (ii) the Zn content of local vegetation (Eucalyptus globulus) in the post-mining site is 2.1 times that in the control site, and (iii) dead bare ground is observed in some parts of the site. There is a possibility that great amounts of Zn and Pb accumulate in tissues of local vegetation. Although mining activity ended 50 years ago, the contents of Pb and Zn in the sampled soil were comparatively high in the site with about a 75% slope. It is concluded that not only the present contamination but also the post-environmental stress should be assessed to properly develop an agricultural area in terms of securing agricultural products.

  14. Contamination of magnetron sputtered metallic films by oxygen from residual atmosphere in deposition chamber

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Petr; Musil, Jindřich; Fitl, Přemysl; Novotný, Michal; Lančok, Ján; Bulíř, Jiří

    2015-01-01

    Roč. 12, č. 5 (2015), s. 416-421 ISSN 1612-8850 R&D Projects: GA ČR(CZ) GAP108/11/1298; GA ČR(CZ) GAP108/11/1312; GA ČR(CZ) GAP108/11/0958; GA ČR(CZ) GA14-10279S Institutional support: RVO:68378271 Keywords : contamination * low-pressure discharges * magnetron * metallic films * sputtering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.713, year: 2015

  15. Contaminant transport at a waste residue deposit: 1. Inverse flow and non-reactive transport modelling

    DEFF Research Database (Denmark)

    Sonnenborg, Torben Obel; Engesgaard, Peter Knudegaard; Rosbjerg, Dan

    1996-01-01

    An application of an inverse flow and transport model to a contaminated aquifer is presented. The objective of the study is to identify physical and nonreactive flow and transport parameters through an optimization approach. The approach can be classified as a statistical procedure, where a flow...... to steady state versus transient flow conditions and to the amount of hydraulic and solute data used is investigated. The flow parameters, transmissivity and leakage factor, are estimated simultaneously with the transport parameters: source strength, porosity, and longitudinal dispersivity. This paper...

  16. Residual radioactive contamination of the test site at Emu from nuclear weapons tests conducted in 1953

    International Nuclear Information System (INIS)

    Maclagan, D.S.; Cooper, M.B.; Duggleby, J.C.

    1979-08-01

    The detailed distributions and soil concentrations of long-lived radionuclides remaining from nuclear weapons trials conducted at Emu in October 1953, are presented. Significant radiation levels due to long-lived neutron activation products in soil, 60 Co and 152 Eu, occur only in the immediate vicinity of the ground zeros of TOTEM 1 and TOTEM 2. It is shown that the levels of contamination due to fallout products in the soil are well below those which would constitute a health hazard to occupants of the area

  17. Bioremediation of Contaminated Soil with Oils Residuals through Bioaugmentation and Natural Attenuation

    Directory of Open Access Journals (Sweden)

    Maitê Carla Deon

    2012-04-01

    Full Text Available The potential for soil contamination by oil spills is growing, due to heavy industrialization and economic development of countries. Due to this fact, the bioremediation has become an alternative to remediate areas through the use of biological agents. Two microorganisms, isolated from a lipid-rich effluent, were used in the bioaugmentation of soils contaminated with diesel oil, lubricating oil and soybean oil. Natural attenuation tests were conducted as controls. The removal of diesel fuel at the time of 21 d were of 18.5%, 7.30% and 11.38%, respectively, for the bioaugmentation with isolated I1 and I2 and natural attenuation. The removal of lubricating oil were 41.6%, 14.16% and 6.91% respectively for the bioaugmentation with the isolated I1 and I2 and natural attenuation, while for soybean oil removals were of 87 8%, 73.9% and 49.4%. Considering the processes of bioaugmentatiom and natural attenuation, the bioaugmentation with the isolated I1 showed better results, possibly due to the production of compounds capable of reducing the surface tension during the preparation of bioaugmentation.

  18. Allowable residual contamination levels of radionuclides in soil from pathway analysis

    International Nuclear Information System (INIS)

    Nyquist, J.E.; Baes, C.F. III.

    1987-01-01

    The uncertainty regarding radionuclide distributions among Remedial Action Program (RAP) sites and long-term decommissioning and closure options for these sites requires a flexible approach capable of handling different levels of contamination, dose limits, and closure scenarios. We identified a commercially available pathway analysis model, DECOM, which had been used previously in support of remedial activities involving contaminated soil at the Savannah River Plant. The DECOM computer code, which estimates concentrations of radionuclides uniformly distributed in soil that correspond to an annual effective dose equivalent, is written in BASIC and runs on an IBM PC or compatible microcomputer. We obtained the latest version of DECOM and modified it to make it more user friendly and applicable to the Oak Ridge National Laboratory (ORNL) RAP. Some modifications involved changes in default parameters or changes in models based on approaches used by the EPA in regulating remedial actions for hazardous substances. We created a version of DECOM as a LOTUS spreadsheet, using the same models as the BASIC version of DECOM. We discuss the specific modeling approaches taken, the regulatory framework that guided our efforts, the strengths and limitations of each approach, and areas for improvement. We also demonstrate how the LOTUS version of DECOM can be applied to specific problems that may be encountered during ORNL RAP activities. 18 refs., 2 figs., 3 tabs

  19. Assessment of alternatives for long-term management of uranium ore residues and contaminated soils located at DOE's Niagara Falls Storage Site

    International Nuclear Information System (INIS)

    Merry-Libby, P.

    1985-01-01

    About 11,000 m 3 of uranium ore residues and 180,000 m 3 of slightly contaminated soils (wastes) are consolidated within a diked containment area at the Niagara Falls Storage Site located about 30 km north of Buffalo, New York. The residues account for less than 6% of the total volume of contaminated materials but almost 99% of the radioactivity. The average radium-226 concentration in the residues is 67,000 pCi/g. The US Department of Energy is considering several alternatives for long-term management of the wastes and residues, including: improvement of the containment at NFSS, modification of the form of the residues, management of the residues separately from the wastes, management of the wastes and residues at another humid site (Oak Ridge, Tennessee) or an arid site (Hanford, Washington), and dispersal of the wastes in the ocean. Potential radiological risks associated with implementation of any of the alternatives are expected to be smaller than the nonradiological risks of occupational and transportation-related injuries and deaths. Dispersal of the slightly contaminated wastes in the ocean is not expected to result in any significant radiological risk to humans. The residues and wastes will remain hazardous for thousands of years. After controls cease, the radioactive materials will eventually be dispersed in the environment. Loss of the earthen covers over the buried materials is predicted to occur from several hundred to more than two million years, depending primarily on the use of the land surface. Groundwater will eventually be contaminated in all alternatives; however, the groundwater pathway is relatively insignificant with respect to radiological risks to the general population. 2 references, 2 figures, 6 tables

  20. Fast heterogeneous N2O5 uptake and ClNO2 production in power plant and industrial plumes observed in the nocturnal residual layer over the North China Plain

    Science.gov (United States)

    Wang, Zhe; Wang, Weihao; Tham, Yee Jun; Li, Qinyi; Wang, Hao; Wen, Liang; Wang, Xinfeng; Wang, Tao

    2017-10-01

    Dinitrogen pentoxide (N2O5) and nitryl chloride (ClNO2) are key species in nocturnal tropospheric chemistry and have significant effects on particulate nitrate formation and the following day's photochemistry through chlorine radical production and NOx recycling upon photolysis of ClNO2. To better understand the roles of N2O5 and ClNO2 in the high-aerosol-loading environment of northern China, an intensive field study was carried out at a high-altitude site (Mt. Tai, 1465 m a.s.l.) in the North China Plain (NCP) during the summer of 2014. Elevated ClNO2 plumes were frequently observed in the nocturnal residual layer with a maximum mixing ratio of 2.1 ppbv (1 min), whilst N2O5 was typically present at very low levels (coal-fired industry and power plants in the NCP. The heterogeneous N2O5 uptake coefficient (γ) and ClNO2 yield (ϕ) were estimated from steady-state analysis and observed growth rate of ClNO2. The derived γ and ϕ exhibited high variability, with means of 0.061 ± 0.025 and 0.28 ± 0.24, respectively. These values are higher than those derived from previous laboratory and field studies in other regions and cannot be well characterized by model parameterizations. Fast heterogeneous N2O5 reactions dominated the nocturnal NOx loss in the residual layer over this region and contributed to substantial nitrate formation of up to 17 µg m-3. The estimated nocturnal nitrate formation rates ranged from 0.2 to 4.8 µg m-3 h-1 in various plumes, with a mean of 2.2 ± 1.4 µg m-3 h-1. The results demonstrate the significance of heterogeneous N2O5 reactivity and chlorine activation in the NCP, and their unique and universal roles in fine aerosol formation and NOx transformation, and thus their potential impacts on regional haze pollution in northern China.

  1. Citric-acid preacidification enhanced electrokinetic remediation for removal of chromium from chromium-residue-contaminated soil.

    Science.gov (United States)

    Meng, Fansheng; Xue, Hao; Wang, Yeyao; Zheng, Binghui; Wang, Juling

    2018-02-01

    Electrokinetic experiments were conducted on chromium-residue-contaminated soils collected from a chemical plant in China. Acidification-electrokinetic remediation technology was proposed in order to solve the problem of removing inefficient with ordinary electrokinetic. The results showed that electrokinetic remediation removal efficiency of chromium from chromium-contaminated soil was significantly enhanced with acidizing pretreatment. The total chromium [Cr(T)] and hexavalent chromium [Cr(VI)] removal rate of the group acidized by citric acid (0.9 mol/L) for 5 days was increased from 6.23% and 19.01% in the acid-free experiments to 26.97% and 77.66% in the acidification-treated experiments, respectively. In addition, part of chromium with the state of carbonate-combined will be converted into water-soluble state through acidification to improve the removal efficiency. Within the appropriate concentration range, the higher concentration of acid was, the more chromium was released. So the removal efficiency of chromium depended on the acid concentration. The citric acid is also a kind of complexing agent, which produced complexation with Cr that was released by the electrokinetic treatment and then enhanced the removal efficiency. The major speciation of chromium that was removed from soils by acidification-electrokinetics remediation was acid-soluble speciation, revivification speciation and oxidation speciation, which reduced biological availability of chromium.

  2. Measurement methodology of vegetable samples from an area affected by residual contamination due to uranium mining sterile; Metodologia de medida de muestras vegetales procedentes de un terreno afectado por contaminacion residual debida a esteriles de mineria de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, N.; Suarez, J. A.; Yague, L.; Ortiz Gandia, M. I.; Marijuan, M. J.; Garcia, E.; Ortiz, T.; Alvarez, A.

    2013-07-01

    This paper presents the methodology established for radiological characterization of plant material generated during the first stage of the realization of a movement of land in an area of land affected by residual contamination due to the burial of sterile of uranium mining. (Author)

  3. [Effect of aeration on composting of date palm residues contaminated with Fusarium oxysporum f.sp. albedinis].

    Science.gov (United States)

    Chakroune, K; Bouakka, M; Hakkou, A

    2005-01-01

    Composting of date palm (Phoenix dactylifera L.) residues contaminated with Fusarium f.sp oxysporum albedinis, causal agent of the vascular wilt (Bayoud) of the date palm, has been achieved. The effect of the aeration of the piles by manual turning has been studied. The maintenance of an adequate humidity of 60%-70%, necessary to the good progress of the composting process, required the contribution of 11.4 L of water/kg of the dried residues. The evolution of the temperatures in the three piles presents the same phases. A latency phase, followed after 2-3 d of composting by a thermophilic phase, which lasts about 24 d, where the temperature remains elevated between 50 and 70 degrees C. Then a cooling phase that takes about 15 d, during which the temperatures fall to values between 25 and 35 degrees C, near room temperature. Fusarium f.sp oxysporum albedinis is eliminated completely during the thermophilic phase of composting, and increasing frequencies of turning accelerate its disappearance to a certain extent. On the other hand, pH remained steady and relatively basic oscillating between 8.2 and 8.7. Ninety percent (90%) of the the date palm residues are composed exclusively of organic matters. The total nitrogen represents only 0.4%. The contribution of manure decreases the ratio of carbon to nitrogen (C/N) from 115 to 48 in the initial mixture. After 80 d of composting and according to the frequency of return up, there is a reduction of the granulometry of the substratum, the C/N ratio (from 29% to 44%), the organic matter (from 15% to 23%), the total volume (from 25% to 35%), and of the dry weight of the swaths (from 16% to 24%). On the other hand there is an increase in total nitrogen rate (from 20% to 40%) and in the mineral matter (from 23% to 35%).

  4. Geotechnical behavior of a tropical residual soil contaminated with soap solution

    Directory of Open Access Journals (Sweden)

    Yamile Valencia-González

    2015-01-01

    Full Text Available Los suelos tropicales son aquellos que debido a factores como el clima, la humedad y otras condiciones propias del trópico, p oseen características físicas, químicas, mineralógicas y mecánicas diferentes a los su elos de las zonas templadas. Dichas particularidades y la acción contaminante en el medio producida por el hombre, son la motivación del presente artículo, el cual pretende analizar u n suelo de origen residual tropical ubicado en el municipio de Guarne – A ntioquia (Colombia, mediante la realización de ensayos de laboratorio, algunos de los cuales son más adecuados para caracterizar este tipo de suelos (Clasificación Miniatura Compactado Tropical, S ucción, Pinhole Test, Desagregación, Índice de Colapso, Dif racción de rayos “X”, Microscopía Electrónica de Barrido, a muestras tanto en estado natural como contaminadas con una solución jabonosa, para establecer las diferencias entre las características geotécn icas de dicho suelo en ambas condiciones y posterior mente, discutir la influencia que tiene el contaminante en sus propiedades.

  5. Glyphosate contaminated soil remediation by atmospheric pressure dielectric barrier discharge plasma and its residual toxicity evaluation.

    Science.gov (United States)

    Wang, Tiecheng; Ren, Jingyu; Qu, Guangzhou; Liang, Dongli; Hu, Shibin

    2016-12-15

    Glyphosate was one of the most widely used herbicides in the world. Remediation of glyphosate-contaminated soil was conducted using atmospheric pressure dielectric barrier discharge (DBD) plasma. The feasibility of glyphosate degradation in soil was explored, and the soil leachate toxicity after remediation was assessed via a seed germination test. The experimental results showed that approximately 93.9% of glyphosate was degraded within 45min of DBD plasma treatment with an energy yield of 0.47gkWh -1 , and the degradation process fitted the first-order kinetic model. Increasing the discharge voltage and decreasing the organic matter content of the soil were both found to facilitate glyphosate degradation. There existed appropriate soil moisture to realize high glyphosate degradation efficiency. Glyphosate mineralization was confirmed by changes of total organic carbon (TOC), chemical oxygen demand (COD), PO 4 3- and NO 3 - . The degradation intermediates including glycine, aminomethylphosphonic acid, acetic acid, formic acid, PO 4 3- and NO 3 - , CO 2 and CO were observed. A possible pathway for glyphosate degradation in the soil using this system was proposed. Based on the soil leachate toxicity test using wheat seed germination, the soil did not exhibit any hazardous effects following high-efficiency glyphosate degradation. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Mapping Pollution Plumes in Areas Impacted by Hurricane Katrina With Imaging Spectroscopy

    Science.gov (United States)

    Swayze, G. A.; Furlong, E. T.; Livo, K. E.

    2007-12-01

    New Orleans endured flooding on a massive scale subsequent to Hurricane Katrina in August of 2005. Contaminant plumes were noticeable in satellite images of the city in the days following flooding. Many of these plumes were caused by oil, gasoline, and diesel that leaked from inundated vehicles, gas stations, and refineries. News reports also suggested that the flood waters were contaminated with sewage from breached pipes. Effluent plumes such as these pose a potential health hazard to humans and wildlife in the aftermath of hurricanes and potentially from other catastrophic events (e.g., earthquakes, shipping accidents, chemical spills, and terrorist attacks). While the extent of effluent plumes can be gauged with synthetic aperture radar and broad- band visible-infrared images (Rykhus, 2005) (e.g., Radarsat and Landsat ETM+) the composition of the plumes could not be determined. These instruments lack the spectral resolution necessary to do chemical identification. Imaging spectroscopy may help solve this problem. Over 60 flight lines of NASA Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data were collected over New Orleans, the Mississippi Delta, and the Gulf Coast from one to two weeks after Katrina while the contaminated water was being pumped out of flooded areas. These data provide a unique opportunity to test if imaging spectrometer data can be used to identify the chemistry of these flood-related plumes. Many chemicals have unique spectral signatures in the ultraviolet to near-infrared range (0.2 - 2.5 microns) that can be used as fingerprints for their identification. We are particularly interested in detecting thin films of oil, gasoline, diesel, and raw sewage suspended on or in water. If these materials can be successfully differentiated in the lab then we will use spectral-shape matching algorithms to look for their spectral signatures in the AVIRIS data collected over New Orleans and other areas impacted by Katrina. If imaging spectroscopy

  7. Evaluation of a recent product to remove lipids and other matrix co-extractives in the analysis of pesticide residues and environmental contaminants in foods

    Science.gov (United States)

    This study demonstrates the application of a novel lipid removal product to the residue analysis of 65 pesticides and 52 environmental contaminants in kale, pork, salmon, and avocado by fast, low pressure gas chromatography – tandem mass spectrometry (LPGC-MS/MS). Sample preparation involves QuEChE...

  8. Ex situ bioremediation of a soil contaminated by mazut (heavy residual fuel oil)--a field experiment.

    Science.gov (United States)

    Beškoski, Vladimir P; Gojgić-Cvijović, Gordana; Milić, Jelena; Ilić, Mila; Miletić, Srdjan; Solević, Tatjana; Vrvić, Miroslav M

    2011-03-01

    Mazut (heavy residual fuel oil)-polluted soil was exposed to bioremediation in an ex situ field-scale (600 m(3)) study. Re-inoculation was performed periodically with biomasses of microbial consortia isolated from the mazut-contaminated soil. Biostimulation was conducted by adding nutritional elements (N, P and K). The biopile (depth 0.4m) was comprised of mechanically mixed polluted soil with softwood sawdust and crude river sand. Aeration was improved by systematic mixing. The biopile was protected from direct external influences by a polyethylene cover. Part (10 m(3)) of the material prepared for bioremediation was set aside uninoculated, and maintained as an untreated control pile (CP). Biostimulation and re-inoculation with zymogenous microorganisms increased the number of hydrocarbon degraders after 50 d by more than 20 times in the treated soil. During the 5 months, the total petroleum hydrocarbon (TPH) content of the contaminated soil was reduced to 6% of the initial value, from 5.2 to 0.3 g kg(-1) dry matter, while TPH reduced to only 90% of the initial value in the CP. After 150 d there were 96%, 97% and 83% reductions for the aliphatic, aromatic, and nitrogen-sulphur-oxygen and asphaltene fractions, respectively. The isoprenoids, pristane and phytane, were more than 55% biodegraded, which indicated that they are not suitable biomarkers for following bioremediation. According to the available data, this is the first field-scale study of the bioremediation of mazut and mazut sediment-polluted soil, and the efficiency achieved was far above that described in the literature to date for heavy fuel oil. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Allowable residual contamination levels for decommissioning the 115-F and 117-F facilities at the Hanford Site

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Napier, B.A.

    1983-07-01

    This report contains the results of a study sponsored by UNC Nuclear Industries to determine Allowable Residual Contamination Levels (ARCL) for the 115-F and 117-F facilities at the Hanford Site. The purpose of this study is to provide data useful to UNC engineers in conducting safety and cost comparisons for decommissioning alternatives. The ARCL results are based on a scenario/exposure-pathway analysis and compliance with an annual dose limit for three specific modes of future use of the land and facilities. These modes of use are restricted, controlled, and unrestricted. Information on restricted and controlled use is provided to permit a full consideration of decommissioning alternatives. Procedures are presented for modifying the ARCL values to accommodate changes in the radionuclide mixture or concentrations and to determine instrument responses for various mixtures of radionuclides. Finally, a comparison is made between existing decommissioning guidance and the ARCL values calculated for unrestricted release of the 115-F and 117-F facilities. The comparison shows a good agreement

  10. Hanford Tanks 241-C-202 and 241-C-203 Residual Waste Contaminant Release Models and Supporting Data

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Mattigod, Shas V.; Schaef, Herbert T.; Arey, Bruce W.

    2007-09-13

    As directed by Congress, the U. S. Department of Energy (DOE) established the Office of River Protection in 1998 to manage DOE's largest, most complex environmental cleanup project – retrieval of radioactive waste from Hanford tanks for treatment and eventual disposal. Sixty percent by volume of the nation's high-level radioactive waste is stored at Hanford in aging deteriorating tanks. If not cleaned up, this waste is a threat to the Columbia River and the Pacific Northwest. CH2M Hill Hanford Group, Inc., is the Office of River Protection's prime contractor responsible for the storage, retrieval, and disposal of Hanford's tank waste. As part of this effort, CH2M HILL Hanford Group, Inc. contracted with Pacific Northwest National Laboratory (PNNL) to develop release models for key contaminants that are present in residual sludge remaining after closure of Hanford Tanks 241-C-203 (C-203) and 241-C-204 (C-204). The release models were developed from data generated by laboratory characterization and testing of samples from these two tanks. These release models are being developed to support the tank closure risk assessments performed by CH2M HILL Hanford Group, Inc., for DOE.

  11. Review of alternative residual contamination guides for the 324 Building B-Cell Cleanout Project. Phase 1

    International Nuclear Information System (INIS)

    Vargo, G.J.; Durham, J.S.; Brackenbush, L.W.

    1995-09-01

    This report provides a proposed residual contamination guide (RCG) for the 324 Building B-Cell Cleanout Project, Phase 1, at the Hanford Site. The RCG is expressed as a fraction of the amount of highly dispersible radioactive material that would result in offsite doses equal to the Pacific Northwest Laboratory radiological risk guidelines following the worst credible accident scenario for release of the holdup material. The proposed RCG is 10 -1 to 10 -2 of the PNL radiological risk guidelines. As part of the development of the RCG, a number of factors were considered. These include the need to provide an appropriate level of flexibility for other activities within the 324 Building that could contribute to the facility's overall radiological risk, uncertainties inherent in safety analyses, and the possible contribution of other 300 Area facilities to overall radiological risk. Because of these factors and the nature of the cleanout project, the RCG is expressed as a range rather than a point value. This report also provides guidance on determining conformance to the RCG, including inspection and measurement techniques, quality assurance requirements, and consideration of uncertainty

  12. A numerical study of the Magellan Plume

    Science.gov (United States)

    Palma, Elbio D.; Matano, Ricardo P.

    2012-05-01

    In this modeling study we investigate the dynamical mechanisms controlling the spreading of the Magellan Plume, which is a low-salinity tongue that extends along the Patagonian Shelf. Our results indicate that the overall characteristics of the plume (width, depth, spreading rate, etc.) are primarily influenced by tidal forcing, which manifests through tidal mixing and tidal residual currents. Tidal forcing produces a homogenization of the plume's waters and an offshore displacement of its salinity front. The interaction between tidal and wind-forcing reinforces the downstream and upstream buoyancy transports of the plume. The influence of the Malvinas Current on the Magellan Plume is more dominant north of 50°S, where it increases the along-shelf velocities and generates intrusions of saltier waters from the outer shelf, thus causing a reduction of the downstream buoyancy transport. Our experiments also indicate that the northern limit of the Magellan Plume is set by a high salinity discharge from the San Matias Gulf. Sensitivity experiments show that increments of the wind stress cause a decrease of the downstream buoyancy transport and an increase of the upstream buoyancy transport. Variations of the magnitude of the discharge produce substantial modifications in the downstream penetration of the plume and buoyancy transport. The Magellan discharge generates a northeastward current in the middle shelf, a recirculation gyre south of the inlet and a region of weak currents father north.

  13. Airborne Gamma-ray Measurements in the Chernobyl Plume

    DEFF Research Database (Denmark)

    Grasty, R. L.; Hovgaard, Jens; Multala, J.

    1997-01-01

    On 29 April 1986, the Geological Survey of Finland (GSF) survey aircraft with a gamma ray spectrometer flew through a radioactive plume from the Chernobyl nuclear accident. The aircraft became contaminated and the gamma spectrometer measured radioactivity in the plume as well as radioactivity...

  14. Independent Technical Review Of The Focused Feasibility Study And Proposed Plan For Designated Solid Waste Management Units Contributing To The Southwest Groundwater Plume At The Paducah Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Looney, B.; Eddy-Dilek, C.; Amidon, M.; Rossabi, J.; Stewart, L.

    2011-01-01

    The U. S. Department of Energy (DOE) is currently developing a Proposed Plan (PP) for remediation of designated sources of chlorinated solvents that contribute contamination to the Southwest (SW) Groundwater Plume at the Paducah Gaseous Diffusion Plant (PGDP), in Paducah, KY. The principal contaminants in the SW Plume are trichloroethene (TCE) and other volatile organic compounds (VOCs); these industrial solvents were used and disposed in various facilities and locations at PGDP. In the SW plume area, residual TCE sources are primarily in the fine-grained sediments of the Upper Continental Recharge System (UCRS), a partially saturated zone that delivers contaminants downward into the coarse-grained Regional Gravel Aquifer (RGA). The RGA serves as the significant lateral groundwater transport pathway for the plume. In the SW Plume area, the four main contributing TCE source units are: (1) Solid Waste Management Unit (SWMU) 1 / Oil Landfarm; (2) C-720 Building TCE Northeast Spill Site (SWMU 211A); (3) C-720 Building TCE Southeast Spill Site (SWMU 211B); and (4) C-747 Contaminated Burial Yard (SWMU 4). The PP presents the Preferred Alternatives for remediation of VOCs in the UCRS at the Oil Landfarm and the C-720 Building spill sites. The basis for the PP is documented in a Focused Feasibility Study (FFS) (DOE, 2011) and a Site Investigation Report (SI) (DOE, 2007). The SW plume is currently within the boundaries of PGDP (i.e., does not extend off-site). Nonetheless, reasonable mitigation of the multiple contaminant sources contributing to the SW plume is one of the necessary components identified in the PGDP End State Vision (DOE, 2005). Because of the importance of the proposed actions DOE assembled an Independent Technical Review (ITR) team to provide input and assistance in finalizing the PP.

  15. INDEPENDENT TECHNICAL REVIEW OF THE FOCUSED FEASIBILITY STUDY AND PROPOSED PLAN FOR DESIGNATED SOLID WASTE MANAGEMENT UNITS CONTRIBUTING TO THE SOUTHWEST GROUNDWATER PLUME AT THE PADUCAH GASEOUS DIFFUSION PLANT

    Energy Technology Data Exchange (ETDEWEB)

    Looney, B.; Eddy-Dilek, C.; Amidon, M.; Rossabi, J.; Stewart, L.

    2011-05-31

    The U. S. Department of Energy (DOE) is currently developing a Proposed Plan (PP) for remediation of designated sources of chlorinated solvents that contribute contamination to the Southwest (SW) Groundwater Plume at the Paducah Gaseous Diffusion Plant (PGDP), in Paducah, KY. The principal contaminants in the SW Plume are trichloroethene (TCE) and other volatile organic compounds (VOCs); these industrial solvents were used and disposed in various facilities and locations at PGDP. In the SW plume area, residual TCE sources are primarily in the fine-grained sediments of the Upper Continental Recharge System (UCRS), a partially saturated zone that delivers contaminants downward into the coarse-grained Regional Gravel Aquifer (RGA). The RGA serves as the significant lateral groundwater transport pathway for the plume. In the SW Plume area, the four main contributing TCE source units are: (1) Solid Waste Management Unit (SWMU) 1 / Oil Landfarm; (2) C-720 Building TCE Northeast Spill Site (SWMU 211A); (3) C-720 Building TCE Southeast Spill Site (SWMU 211B); and (4) C-747 Contaminated Burial Yard (SWMU 4). The PP presents the Preferred Alternatives for remediation of VOCs in the UCRS at the Oil Landfarm and the C-720 Building spill sites. The basis for the PP is documented in a Focused Feasibility Study (FFS) (DOE, 2011) and a Site Investigation Report (SI) (DOE, 2007). The SW plume is currently within the boundaries of PGDP (i.e., does not extend off-site). Nonetheless, reasonable mitigation of the multiple contaminant sources contributing to the SW plume is one of the necessary components identified in the PGDP End State Vision (DOE, 2005). Because of the importance of the proposed actions DOE assembled an Independent Technical Review (ITR) team to provide input and assistance in finalizing the PP.

  16. Degradability of n-alkanes during ex situ natural bioremediation of soil contaminated by heavy residual fuel oil (mazut

    Directory of Open Access Journals (Sweden)

    Ali Ramadan Mohamed Muftah

    2013-01-01

    Full Text Available It is well known that during biodegradation of oil in natural geological conditions, or oil pollutants in the environment, a degradation of hydrocarbons occurs according to the well defined sequence. For example, the major changes during the degradation process of n-alkanes occur in the second, slight and third, moderate level (on the biodegradation scale from 1 to 10. According to previous research, in the fourth, heavy level, when intensive changes of phenanthrene and its methyl isomers begin, n-alkanes have already been completely removed. In this paper, the ex situ natural bioremediation (unstimulated bioremediation, without addition of biomass, nutrient substances and biosurfactant of soil contaminated with heavy residual fuel oil (mazut was conducted during the period of 6 months. Low abundance of n-alkanes in the fraction of total saturated hydrocarbons in the initial sample (identification was possible only after concentration by urea adduction technique showed that the investigated oil pollutant was at the boundary between the third and the fourth biodegradation level. During the experiment, an intense degradation of phenanthrene and its methyl-, dimethyl-and trimethyl-isomers was not followed by the removal of the remaining n-alkanes. The abundance of n-alkanes remained at the initial low level, even at end of the experiment when the pollutant reached one of the highest biodegradation levels. These results showed that the unstimulated biodegradation of some hydrocarbons, despite of their high biodegradability, do not proceed completely to the end, even at final degradation stages. In the condition of the reduced availability of some hydrocarbons, microorganisms tend to opt for less biodegradable but more accessible hydrocarbons.

  17. Slow pyrolyzed biochars from crop residues for soil metal(loid) immobilization and microbial community abundance in contaminated agricultural soils.

    Science.gov (United States)

    Igalavithana, Avanthi Deshani; Park, Jinje; Ryu, Changkook; Lee, Young Han; Hashimoto, Yohey; Huang, Longbin; Kwon, Eilhann E; Ok, Yong Sik; Lee, Sang Soo

    2017-06-01

    This study evaluated the feasibility of using biochars produced from three types of crop residues for immobilizing Pb and As and their effects on the abundance of microbial community in contaminated lowland paddy (P-soil) and upland (U-soil) agricultural soils. Biochars were produced from umbrella tree [Maesopsis eminii] wood bark [WB], cocopeat [CP], and palm kernel shell [PKS] at 500 °C by slow pyrolysis at a heating rate of 10 °C min -1 . Soils were incubated with 5% (w w -1 ) biochars at 25 °C and 70% water holding capacity for 45 d. The biochar effects on metal immobilization were evaluated by sequential extraction of the treated soil, and the microbial community was determined by microbial fatty acid profiles and dehydrogenase activity. The addition of WB caused the largest decrease in Pb in the exchangeable fraction (P-soil: 77.7%, U-soil: 91.5%), followed by CP (P-soil: 67.1%, U-soil: 81.1%) and PKS (P-soil: 9.1%, U-soil: 20.0%) compared to that by the control. In contrast, the additions of WB and CP increased the exchangeable As in U-soil by 84.6% and 14.8%, respectively. Alkalinity and high phosphorous content of biochars might be attributed to the Pb immobilization and As mobilization, respectively. The silicon content in biochars is also an influencing factor in increasing the As mobility. However, no considerable effects of biochars on the microbial community abundance and dehydrogenase activity were found in both soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Paducah Gaseous Diffusion Plant Northwest Plume interceptor system evaluation

    International Nuclear Information System (INIS)

    Laase, A.D.; Clausen, J.L.

    1998-01-01

    The Paducah Gaseous Diffusion Plant (PGDP) recently installed an interceptor system consisting of four wells, evenly divided between two well fields, to contain the Northwest Plume. As stated in the Northwest Plume Record of Decision (ROD), groundwater will be pumped at a rate to reduce further contamination and initiate control of the northwest contaminant plume. The objective of this evaluation was to determine the optimum (minimal) well field pumping rates required for plume hotspot containment. Plume hotspot, as defined in the Northwest Plume ROD and throughout this report, is that portion of the plume with trichloroethene (TCE) concentrations greater than 1,000 microg/L. An existing 3-dimensional groundwater model was modified and used to perform capture zone analyses of the north and south interceptor system well fields. Model results suggest that the plume hotspot is not contained at the system design pumping rate of 100 gallons per minute (gal/min) per well field. Rather, the modeling determined that north and south well field pumping rates of 400 and 150 gal/min, respectively, are necessary for plume hotspot containment. The difference between the design and optimal pumping rates required for containment can be attributed to the discovery of a highly transmissive zone in the vicinity of the two well fields

  19. Fossil plume head beneath the Arabian lithosphere?

    Science.gov (United States)

    Stein, Mordechai; Hofmann, Albrecht W.

    1992-12-01

    Phanerozoic alkali basalts from Israel, which have erupted over the past 200 Ma, have isotopic compositions similar to PREMA ("prevalent mantle") with narrow ranges of initial ɛ Nd(T) = +3.9-+5.9; 87Sr/ 86Sr(T)= 0.70292-0.70334; 206Pb/ 204Pb(T)= 18.88-19.99; 207Pb/ 204Pb(T)= 15.58-15.70; and 208Pb/ 204Pb(T)= 38.42-39.57. Their Nb/U(43 ± 9) and Ce/Pb(26 ± 6) ratios are identical to those of normal oceanic basalts, demonstrating that the basalts are essentially free of crustal contamination. Overall, the basalts are chemically and isotopically indistinguishable from many ordinary plume basalts, but no plume track can be identified. We propose that these and other, similar, magmas from the Arabian plate originated from a "fossilized" head of a mantle plume, which was unable to penetrate the continental lithosphere and was therefore trapped and stored beneath it. The plume head was emplaced some time between the late Proterozoic crust formation and the initiation of the Phanerozoic magmatic cycles. Basalts from rift environments in other continental localities show similar geochemistry to that of the Arabian basalts and their sources may also represent fossil plume heads trapped below the continents. We suggest that plume heads are, in general, characterized by the PREMA isotopic mantle signature, because the original plume sources (which may have HIMU or EM-type composition) have been diluted by overlying mantle material, which has been entrained by the plume heads during ascent. On the Arabian plate, rifting and thinning of the lithosphere caused partial melting of the stored plume, which led to periodic volcanism. In the late Cenozoic, the lithosphere broke up and the Red Sea opened. N-MORB tholeiites are now erupting in the central trough of the Red Sea, where the lithosphere has moved apart and the fossil plume has been exhausted, whereas E-MORBs are erupting in the northern and southern troughs, still tapping the plume reservoir. Fossil plumes, which are

  20. Radiation protection of radioactively contaminated large areas by phytoremediation and subsequent utilization of the contaminated plant residues (PHYTOREST); Massnahmen zur Strahlenschutzvorsorge radioaktiv belasteter Grossflaechen durch Sanierung mittels Phytoremediation und anschliessende Verwertung der belasteten Pflanzenreststoffe (PHYTOREST)

    Energy Technology Data Exchange (ETDEWEB)

    Mirgorodsky, Daniel; Ollivier, Delphine; Merten, Dirk; Bergmann, Hans; Buechel, Georg [Jena Univ. (Germany). Inst. fuer Geowissenschaften; Willscher, Sabine; Wittig, Juliane; Jablonski, Lukasz; Werner, Peter [Technische Univ. Dresden, Pirna (Germany). Inst. fuer Abfallwirtschaft und Altlasten

    2010-12-15

    Much progress has been achieved over the past 20 years in remediating sites contaminated by heavy metal. However, very large contaminated areas have presented major problems to this day because of remediation costs. Phytoremediation is a new, emerging, sustainable technique of remediating areas with low heavy-metal contamination. One advantage of phytoremediation is the comparatively low cost of the process, which may make it usable also on large areas with low levels of contamination. Besides extracting and immobilizing metals, respectively, phytoremediation among other things also contributes to improving soil quality in terms of physics, chemistry, and ecology. Consequently, phytoremediation offers a great potential for the future. Research into phytoremediation of an area contaminated by heavy metals and radionuclides is carried out on a site in a former uranium mining district in Eastern Thuringia jointly by the Friedrich Schiller University, Jena, and the Technical University of Dresden in a project funded by the German Federal Ministry for Education and Research. The project serves to promote the introduction of soft, biocompatible methods of long-term remediation and to develop conceptual solutions to the subsequent utilization of contaminated plant residues. Optimizing area management is in the focus of phytoremediation studies. (orig.)

  1. Entrainment by turbulent plumes

    Science.gov (United States)

    Parker, David; Burridge, Henry; Partridge, Jamie; Linden, Paul

    2017-11-01

    Plumes are of relevance to nature and real consequence to industry. While the Morton, Taylor & Turner (1956) plume model is able to estimate the mean physical flux parameters, the process of entrainment is only parametrised in a time-averaged sense and a deeper understanding is key to understanding how they evolve. Various flow configurations, resulting in different entrainment values, are considered; we perform simultaneous PIV and plume-edge detection on saline plumes in water resulting from a point source, a line source and a line source where a vertical wall is placed immediately adjacent. Of particular interest is the effect the large scale eddies, forming at the edge of the plume and engulfing ambient fluid, have on the entrainment process. By using velocity statistics in a coordinate system based on the instantaneous scalar edge of the plume the significance of this large scale engulfment is quantified. It is found that significant mass is transported outside the plumes, in particular in regions where large scale structures are absent creating regions of relatively high-momentum ambient fluid. This suggests that the large scale processes, whereby ambient fluid is engulfed into the plume, contribute significantly to the entrainment.

  2. Quantification of pressure sensitive adhesive, residual ink, and other colored process contaminants using dye and color image analysis

    Science.gov (United States)

    Roy R. Rosenberger; Carl J. Houtman

    2000-01-01

    The USPS Image Analysis (IA) protocol recommends the use of hydrophobic dyes to develop contrast between pressure sensitive adhesive (PSA) particles and cellulosic fibers before using a dirt counter to detect all contaminants that have contrast with the handsheet background. Unless the sample contains no contaminants other than those of interest, two measurement steps...

  3. Report of the Scientific Committee of the Spanish Agency for Consumer Affairs, Food Safety and Nutrition (AECOSAN) in relation to the risk of the presence of sulphonamide residues in eggs resulting from cross-contamination in feed production

    OpenAIRE

    Scientific Committee

    2017-01-01

    Sulphonamides can be administered by adding them to feed within the framework of legal use to treat diseases in animals intended for use in the production of foods, except laying hens. Furthermore, in feed production, cross-contaminations can occur from medicated feed that lead to the appearance of residues of these medicines in animal by-products. In particular, on some occasions, sulphonamide residues have been detected in eggs resulting from cross-contamination in feed production. The Scie...

  4. PHYSICOCHEMICAL CHARACTERISTICS, PESTICIDE RESIDUE AND AFLATOXIN CONTAMINATION OF COLD PRESSED PUMPKIN SEED (Cucurbita pepo L. OILS FROM CENTRAL ANATOLIA REGION OF TURKEY

    Directory of Open Access Journals (Sweden)

    FATMA NUR ARSLAN

    2017-06-01

    Full Text Available In this study, physicochemical characteristics, pesticide residues and aflatoxin contaminations of cold pressed pumpkin seed (Cucurbita pepo L. oils cultivated in four different central Anatolia regions of Turkey, were investigated. Lab-scale screw press machine was used to produce cold pressed pumpkin seed oils and the oil contents were found between 42.8%−47.4% for naked seeds. The physicochemical characteristic (refractive index, viscosity, color value, triglyceride profile analysis, peroxide value, iodine value, free fatty acid, saponification number, unsaponified matter, specific extinction values at 232 and 270 nm of cold pressed oils were determined by using different analytical techniques. The results showed that there was a non-significant difference between cold pressed pumpkin seed oils from different regions, in terms of physicochemical characteristics. The contents of pesticide residue and aflatoxin B1, B2, G1 and G2 contamination were determined by using validated UHPLC-MS/MS method. The chlorpyrifos pesticide residue was detected under the limit value declared by official authorities for the quality assessment of edible oils. Aflatoxins weren’t detected in any of studied pumpkin seed oils. Therefore, in food industry the positive effect of screw-pressing application could be useful for preservation of bioactive compounds during edible oil production and also enhancing of their functional properties.

  5. Comparison of two freshwater turtle species as monitors of radionuclide and chemical contamination: DNA damage and residue analysis

    International Nuclear Information System (INIS)

    Meyers-Schoene, L.; Shugart, L.R.; Beauchamp, J.J.; Walton, B.T.

    1993-01-01

    Two species of turtles that occupy different ecological niches were compared for their usefulness as monitors of freshwater ecosystems where both low-level radioactive and nonradioactive contaminants are present. The pond slider (Trachemys scripta) and common snapping turtle (Chelydra serpentina) were analyzed for the presence of 90 Sr, 137 Cs, 60 Co, and Hg, radionuclides and chemicals known to be present at the contaminated site, and single-strand breaks in liver DNA. The integrity of the DNA was examined by the alkaline unwinding assay, a technique that detects strand breaks as a biological marker of possible exposure to genotoxic agents. This measure of DNA damage was significantly increased in both species of turtles at the contaminated site compared with turtles of the same species at a reference site, and shows that contaminant-exposed populations were under more severe genotoxic stress than those at the reference site. The level of strand breaks observed at the contaminated site was high and in the range reported for other aquatic species exposed to deleterious concentrations of genotoxic agents such as chemicals and ionizing radiation. Statistically significantly higher concentrations of radionuclides and Hg were detected in the turtles from the contaminated area. Mercury concentrations were significantly higher in the more carnivorous snapping turtle compared with the slider; however, both species were effective monitors of the contaminants

  6. Solar Coronal Plumes

    Directory of Open Access Journals (Sweden)

    Giannina Poletto

    2015-12-01

    Full Text Available Polar plumes are thin long ray-like structures that project beyond the limb of the Sun polar regions, maintaining their identity over distances of several solar radii. Plumes have been first observed in white-light (WL images of the Sun, but, with the advent of the space era, they have been identified also in X-ray and UV wavelengths (XUV and, possibly, even in in situ data. This review traces the history of plumes, from the time they have been first imaged, to the complex means by which nowadays we attempt to reconstruct their 3-D structure. Spectroscopic techniques allowed us also to infer the physical parameters of plumes and estimate their electron and kinetic temperatures and their densities. However, perhaps the most interesting problem we need to solve is the role they cover in the solar wind origin and acceleration: Does the solar wind emanate from plumes or from the ambient coronal hole wherein they are embedded? Do plumes have a role in solar wind acceleration and mass loading? Answers to these questions are still somewhat ambiguous and theoretical modeling does not provide definite answers either. Recent data, with an unprecedented high spatial and temporal resolution, provide new information on the fine structure of plumes, their temporal evolution and relationship with other transient phenomena that may shed further light on these elusive features.

  7. Persistence of uranium groundwater plumes: Contrasting mechanisms at two DOE sites in the groundwater-river interaction zone

    Science.gov (United States)

    Zachara, John M.; Long, Philip E.; Bargar, John; Davis, James A.; Fox, Patricia; Fredrickson, Jim K.; Freshley, Mark D.; Konopka, Allan E.; Liu, Chongxuan; McKinley, James P.; Rockhold, Mark L.; Williams, Kenneth H.; Yabusaki, Steve B.

    2013-04-01

    residual, contaminant U; the rates of current kinetic processes (both biotic and abiotic) influencing U(VI) solid-liquid distribution; the presence of detrital organic matter and the resulting spatial heterogeneity in microbially-driven redox properties; and the magnitude of groundwater hydrologic dynamics controlled by river-stage fluctuations, geologic structures, and aquifer hydraulic properties. The comparative analysis of these sites provides important guidance to the characterization, understanding, modeling, and remediation of groundwater contaminant plumes influenced by surface water interaction that are common world-wide.

  8. Persistence of uranium groundwater plumes: contrasting mechanisms at two DOE sites in the groundwater-river interaction zone.

    Science.gov (United States)

    Zachara, John M; Long, Philip E; Bargar, John; Davis, James A; Fox, Patricia; Fredrickson, Jim K; Freshley, Mark D; Konopka, Allan E; Liu, Chongxuan; McKinley, James P; Rockhold, Mark L; Williams, Kenneth H; Yabusaki, Steve B

    2013-04-01

    residual, contaminant U; the rates of current kinetic processes (both biotic and abiotic) influencing U(VI) solid-liquid distribution; the presence of detrital organic matter and the resulting spatial heterogeneity in microbially-driven redox properties; and the magnitude of groundwater hydrologic dynamics controlled by river-stage fluctuations, geologic structures, and aquifer hydraulic properties. The comparative analysis of these sites provides important guidance to the characterization, understanding, modeling, and remediation of groundwater contaminant plumes influenced by surface water interaction that are common world-wide. Copyright © 2013. Published by Elsevier B.V.

  9. Properties of plutonium-contaminated particles resulting from British Vixen B trials at Maralinga

    International Nuclear Information System (INIS)

    Burns, P.A.; Cooper, M.B.; Williams, G.A.; Johnston, P.N.

    1990-12-01

    Since 1984 a number of studies have been performed to investigate residual contamination at the former atomic weapons test site at Maralinga in South Australia, and to aid in the rehabilitation of the area. The largest site of plutonium contamination at Maralinga results from twelve Vixen B trials conduced at Taranaki in 1960, 1961 and 1963. Plutonium was dispersed along four major plumes from these trials. Measurements of the ratios of activities of 239 Pu and 240 Pu to 241 Am are presented for the plumes. These are identified with individual trials where possible. Some measurements have also been made of 235 U activities. An examination of meteorological and health physics survey data suggests that the most extensive part of the north-west plume results from a single trial, viz. Vixen B2 round 5 of 1961. It appears that the level of contamination in this plume was augmented by rainout of material, and the extent of the plume was enhanced by the considerable wind speed at the time. Results of proton-induced X-ray emission spectroscopy (PIXE), which provides elemental content and maps of the distribution of elements on the surface of some of the active particles, are presented, together with some other physical characteristics of the particles, in the expectation that these will aid in hazard assessment and with the development of techniques to rehabilitate the Taranaki site at Maralinga. 17 refs., 4 tabs., 1 fig

  10. Chemistry in aircraft plumes

    Energy Technology Data Exchange (ETDEWEB)

    Kraabol, A.G.; Stordal, F.; Knudsen, S. [Norwegian Inst. for Air Research, Kjeller (Norway); Konopka, P. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    An expanding plume model with chemistry has been used to study the chemical conversion of NO{sub x} to reservoir species in aircraft plumes. The heterogeneous conversion of N{sub 2}O{sub 5} to HNO{sub 3}(s) has been investigated when the emissions take place during night-time. The plume from an B747 has been simulated. During a ten-hour calculation the most important reservoir species was HNO{sub 3} for emissions at noon. The heterogeneous reactions had little impact on the chemical loss of NO{sub x} to reservoir species for emissions at night. (author) 4 refs.

  11. Chemistry in aircraft plumes

    Energy Technology Data Exchange (ETDEWEB)

    Kraabol, A G; Stordal, F; Knudsen, S [Norwegian Inst. for Air Research, Kjeller (Norway); Konopka, P [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

    1998-12-31

    An expanding plume model with chemistry has been used to study the chemical conversion of NO{sub x} to reservoir species in aircraft plumes. The heterogeneous conversion of N{sub 2}O{sub 5} to HNO{sub 3}(s) has been investigated when the emissions take place during night-time. The plume from an B747 has been simulated. During a ten-hour calculation the most important reservoir species was HNO{sub 3} for emissions at noon. The heterogeneous reactions had little impact on the chemical loss of NO{sub x} to reservoir species for emissions at night. (author) 4 refs.

  12. Stabilization of in-tank residual wastes and external-tank soil contamination for the tank focus area, Hanford tank initiative: Applications to the AX Tank Farm

    International Nuclear Information System (INIS)

    Balsley, S.D.; Krumhansl, J.L.; Borns, D.J.; McKeen, R.G.

    1998-07-01

    A combined engineering and geochemistry approach is recommended for the stabilization of waste in decommissioned tanks and contaminated soils at the AX Tank Farm, Hanford, WA. A two-part strategy of desiccation and gettering is proposed for treatment of the in-tank residual wastes. Dry portland cement and/or fly ash are suggested as an effective and low-cost desiccant for wicking excess moisture from the upper waste layer. Getters work by either ion exchange or phase precipitation to reduce radionuclide concentrations in solution. The authors recommend the use of specific natural and man-made compounds, appropriately proportioned to the unique inventory of each tank. A filler design consisting of multilayered cementitous grout with interlayered sealant horizons should serve to maintain tank integrity and minimize fluid transport to the residual waste form. External tank soil contamination is best mitigated by placement of grouted skirts under and around each tank, together with installation of a cone-shaped permeable reactive barrier beneath the entire tank farm. Actinide release rates are calculated from four tank closure scenarios ranging from no action to a comprehensive stabilization treatment plan (desiccant/getters/grouting/RCRA cap). Although preliminary, these calculations indicate significant reductions in the potential for actinide transport as compared to the no-treatment option

  13. Cross-Contamination of Residual Emerging Contaminants and Antibiotic Resistant Bacteria in Lettuce Crops and Soil Irrigated with Wastewater Treated by Sunlight/H2O2.

    Science.gov (United States)

    Ferro, Giovanna; Polo-López, María I; Martínez-Piernas, Ana B; Fernández-Ibáñez, Pilar; Agüera, Ana; Rizzo, Luigi

    2015-09-15

    The sunlight/H2O2 process has recently been considered as a sustainable alternative option compared to other solar driven advanced oxidation processes (AOPs) in advanced treatment of municipal wastewater (WW) to be reused for crop irrigation. Accordingly, in this study sunlight/H2O2 was used as disinfection/oxidation treatment for urban WW treatment plant effluent in a compound parabolic collector photoreactor to assess subsequent cross-contamination of lettuce and soil by contaminants of emerging concern (CECs) (determined by QuEChERS extraction and LC-QqLIT-MS/MS analysis) and antibiotic resistant (AR) bacteria after irrigation with treated WW. Three CECs (carbamazepine (CBZ), flumequine (FLU), and thiabendazole (TBZ) at 100 μg L(-1)) and two AR bacterial strains (E. coli and E. faecalis, at 10(5) CFU mL(-1)) were spiked in real WW. A detection limit (DL) of 2 CFU mL(-1) was reached after 120 min of solar exposure for AR E. coli, while AR E. faecalis was more resistant to the disinfection process (240 min to reach DL). CBZ and TBZ were poorly removed after 90 min (12% and 50%, respectively) compared to FLU (94%). Lettuce was irrigated with treated WW for 5 weeks. CBZ and TBZ were accumulated in soil up to 472 ng g(-1) and 256 ng g(-1) and up-taken by lettuce up to 109 and 18 ng g(-1), respectively, when 90 min treated WW was used for irrigation; whereas no bacteria contamination was observed when the bacterial density in treated WW was below the DL. A proper treatment time (>90 min) should be guaranteed in order to avoid the transfer of pathogens from disinfected WW to irrigated crops and soil.

  14. The Food Safety of Livestock Products (Meatball, Corned Beef, Beef Burger and Sausage Studied from Heavy Metal Residues Contamination

    Directory of Open Access Journals (Sweden)

    E Harlia

    2010-01-01

    Full Text Available The aims of animal husbandry improvements are to increase both the quality and the quantity of livestock production and to ensure the safety of the product. It is necessarry for consumers to pay attention to the food safety of livestock product because it is related to human's health. The research was conducted to determine the food safety of livestock product condition by detecting heavy metal residues on several food products from livestock like meatball, corned beef, burger’s beef, and sausages. This research was explored by using survey's method and purposive technique sampling, then the resulted data were descriptively analyzed. The observed variables were heavy metal contents such as Plumbum (Pb and Cadmium (Cd in which being measured by using AAS (Atomic Absorption Spectrophotometri . The result showed that in general, heavy metal residue of Pb from several livestock products (meatball, corned beef, beef burger, and sausages were smaller than Maximum Residue Limit (MRL, while the Cd’s residue was partly over the MRL concentration, therefore further action has to be taken as it affects the human's health. (Animal Production 12(1: 50-54 (2010 Key words : food safety, MRL, heavy metal Pb, Cd.

  15. Subsurface contaminants focus area

    International Nuclear Information System (INIS)

    1996-08-01

    The US Department of Enregy (DOE) Subsurface Contaminants Focus Area is developing technologies to address environmental problems associated with hazardous and radioactive contaminants in soil and groundwater that exist throughout the DOE complex, including radionuclides, heavy metals; and dense non-aqueous phase liquids (DNAPLs). More than 5,700 known DOE groundwater plumes have contaminated over 600 billion gallons of water and 200 million cubic meters of soil. Migration of these plumes threatens local and regional water sources, and in some cases has already adversely impacted off-site rsources. In addition, the Subsurface Contaminants Focus Area is responsible for supplying technologies for the remediation of numerous landfills at DOE facilities. These landfills are estimated to contain over 3 million cubic meters of radioactive and hazardous buried Technology developed within this specialty area will provide efective methods to contain contaminant plumes and new or alternative technologies for development of in situ technologies to minimize waste disposal costs and potential worker exposure by treating plumes in place. While addressing contaminant plumes emanating from DOE landfills, the Subsurface Contaminants Focus Area is also working to develop new or alternative technologies for the in situ stabilization, and nonintrusive characterization of these disposal sites

  16. Subsurface contaminants focus area

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    The US Department of Enregy (DOE) Subsurface Contaminants Focus Area is developing technologies to address environmental problems associated with hazardous and radioactive contaminants in soil and groundwater that exist throughout the DOE complex, including radionuclides, heavy metals; and dense non-aqueous phase liquids (DNAPLs). More than 5,700 known DOE groundwater plumes have contaminated over 600 billion gallons of water and 200 million cubic meters of soil. Migration of these plumes threatens local and regional water sources, and in some cases has already adversely impacted off-site rsources. In addition, the Subsurface Contaminants Focus Area is responsible for supplying technologies for the remediation of numerous landfills at DOE facilities. These landfills are estimated to contain over 3 million cubic meters of radioactive and hazardous buried Technology developed within this specialty area will provide efective methods to contain contaminant plumes and new or alternative technologies for development of in situ technologies to minimize waste disposal costs and potential worker exposure by treating plumes in place. While addressing contaminant plumes emanating from DOE landfills, the Subsurface Contaminants Focus Area is also working to develop new or alternative technologies for the in situ stabilization, and nonintrusive characterization of these disposal sites.

  17. A STUDY OF DISSOLUTION RATE-LIMITED BIOREMEDIATION OF SOILS CONTAMINATED BY RESIDUAL HYDROCARBONS. (R825549C039)

    Science.gov (United States)

    The widespread release of organic chemicals in the environment frequently leads to ground-water contamination with non-aqueous phase liquids (NAPLs) because many of these organic chemicals are barely soluble in water. Understanding the mechanisms of transport and biotic transf...

  18. Stabilization of In-Tank Residual Wastes and External-Tank Soil Contamination for the Hanford Tank Closure Program: Applications to the AX Tank Farm

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, H.L.; Dwyer, B.P.; Ho, C.; Krumhansl, J.L.; McKeen, G.; Molecke, M.A.; Westrich, H.R.; Zhang, P.

    1998-11-01

    Technical support for the Hanford Tank Closure Program focused on evaluation of concepts for immobilization of residual contaminants in the Hanford AX tanks and underlying soils, and identification of cost-effective approaches to improve long-term performance of AX tank farm cIosure systems. Project objectives are to develop materials or engineered systems that would significantly reduce the radionuclide transport to the groundwater from AX tanks containing residual waste. We pursued several studies that, if implemented, would help achieve these goals. They include: (1) tank fill design to reduce water inilltration and potential interaction with residual waste; (2) development of in-tank getter materials that would specifically sorb or sequester radionuclides; (3) evaluation of grout emplacement under and around the tanks to prevent waste leakage during waste retrieval or to minimize water infiltration beneath the tanks; (4) development of getters that will chemically fix specific radionuclides in soils under tanks; and (5) geochemical and hydrologic modeling of waste-water-soil-grout interactions. These studies differ in scope from the reducing grout tank fill employed at the Savannah River Site in that our strategy improves upon tank fill design by providing redundancy in the barriers to radionuclide migration and by modification the hydrogeochemistry external to the tanks.

  19. Organochlorine residues in harp seals, Phoca groenlandica, from the Gulf of St. Lawrence and Hudson Strait: An evaluation of contaminant concentrations and burdens

    Energy Technology Data Exchange (ETDEWEB)

    Beck, G.G.; Smith, T.G. (Dept. of Fisheries and Oceans, Nanaimo, BC (Canada)); Addison, R.F. (Dept. of Fisheries and Oceans, Sidney, BC (Canada))

    1994-01-01

    Organochlorine contaminant concentrations and burdens were evaluated in blubber samples from 50 harp seals (Phoca groenlandica) obtained from the estuary and northern Gulf of St. Lawrence and Hudson Strait, Canada between December 1988 and December 1989. The concentration and burden of polychlorinated biphenyls (PCBs) increased significantly during the winter months for males occupying the St. Lawrence estuary. The potential for rapid accumulation of contaminants in the estuary was also observed among females: nine postpartum females (1 month after weaning) had higher organochlorine levels than prepartum females from the same location. The lowest observed contaminant concentrations and burdens were in seals from Hudson Strait in autumn. In winter specimens, males had DDT and PCB concentrations about 4 and 2 times as great, respectively, as females of similar age distribution and collection date. Congeners with IUPAC Nos. 138 and 153 accounted for more than 50% of total identifiable PCBs, which is consistent with their prevalence in other marine biota. The concentration of PCBs has declined and the percent p,p'-DDE of total DDT has increased between 1982 and the present study. Unlike the beluga whale (Delphinapterus leucas), harp seals occupy the more polluted waters of the estuary only seasonally, and this may account for their lower residue concentrations. 59 refs., 1 fig., 5 tabs.

  20. River plume patterns and dynamics within the Southern California Bight

    Science.gov (United States)

    Warrick, J.A.; DiGiacomo, P.M.; Weisberg, S.B.; Nezlin, N.P.; Mengel, M.; Jones, B.H.; Ohlmann, J.C.; Washburn, L.; Terrill, E.J.; Farnsworth, K.L.

    2007-01-01

    Stormwater river plumes are important vectors of marine contaminants and pathogens in the Southern California Bight. Here we report the results of a multi-institution investigation of the river plumes across eight major river systems of southern California. We use in situ water samples from multi-day cruises in combination with MODIS satellite remote sensing, buoy meteorological observations, drifters, and HF radar current measurements to evaluate the dispersal patterns and dynamics of the freshwater plumes. River discharge was exceptionally episodic, and the majority of storm discharge occurred in a few hours. The combined plume observing techniques revealed that plumes commonly detach from the coast and turn to the left, which is the opposite direction of Coriolis influence. Although initial offshore velocity of the buoyant plumes was ∼50 cm/s and was influenced by river discharge inertia (i.e., the direct momentum of the river flux) and buoyancy, subsequent advection of the plumes was largely observed in an alongshore direction and dominated by local winds. Due to the multiple day upwelling wind conditions that commonly follow discharge events, plumes were observed to flow from their respective river mouths to down-coast waters at rates of 20–40 km/d. Lastly, we note that suspended-sediment concentration and beam-attenuation were poorly correlated with plume salinity across and within the sampled plumes (mean r2=0.12 and 0.25, respectively), while colored dissolved organic matter (CDOM) fluorescence was well correlated (mean r2=0.56), suggesting that CDOM may serve as a good tracer of the discharged freshwater in subsequent remote sensing and monitoring efforts of plumes.

  1. Overcoming the problem of residual microbial contamination in dental suction units left by conventional disinfection using novel single component suction handpieces in combination with automated flood disinfection.

    Science.gov (United States)

    Boyle, M A; O'Donnell, M J; Russell, R J; Galvin, N; Swan, J; Coleman, D C

    2015-10-01

    Decontaminating dental chair unit (DCU) suction systems in a convenient, safe and effective manner is problematic. This study aimed to identify and quantify the extent of the problems using 25 DCUs, methodically eliminate these problems and develop an efficient approach for reliable, effective, automated disinfection. DCU suction system residual contamination by environmental and human-derived bacteria was evaluated by microbiological culture following standard aspiration disinfection with a quaternary ammonium disinfectant or alternatively, a novel flooding approach to disinfection. Disinfection of multicomponent suction handpieces, assembled and disassembled, was also studied. A prototype manual and a novel automated Suction Tube Cleaning System (STCS) were developed and tested, as were novel single component suction handpieces. Standard aspiration disinfection consistently failed to decontaminate DCU suction systems effectively. Semi-confluent bacterial growth (101-500 colony forming units (CFU) per culture plate) was recovered from up to 60% of suction filter housings and from up to 19% of high and 37% of low volume suction hoses. Manual and automated flood disinfection of DCU suction systems reduced this dramatically (ranges for filter cage and high and low volume hoses of 0-22, 0-16 and 0-14CFU/plate, respectively) (P<0.0001). Multicomponent suction handpieces could not be adequately disinfected without prior removal and disassembly. Novel single component handpieces, allowed their effective disinfection in situ using the STCS, which virtually eliminated contamination from the entire suction system. Flood disinfection of DCU suction systems and single component handpieces radically improves disinfection efficacy and considerably reduces potential cross-infection and cross-contamination risks. DCU suction systems become heavily contaminated during use. Conventional disinfection does not adequately control this. Furthermore, multicomponent suction handpieces

  2. Measures for radiation prevention and remediation of islightly radioactive contaminated sites by phytoremediation and subsequent utilization of the loaded plant residues (PHYTOREST). Final report

    International Nuclear Information System (INIS)

    Willscher, Sabine; Werner, Peter; Jablonski, Lukasz; Wittig, Juliane

    2013-01-01

    contaminated geosubstrates now can be carried out within the radiation protection regulations. Hence, the project provides a substantial contribution to the radiation protection of HM/R contaminated soils. Within the research project, ways for the utilization of HM/R- contaminated plant residuals were highlighted; this gives a substantial contribution for minimization of wastes, the winning of sustainable bioenergy and the recycling of materials. Here, different ways of solutions were investigated. The research project was carried out within the scientific funding program ''Closedown and decommissioning of nuclear facilities''. The results of the project will contribute to the development of a biologically benign, sustainable technique for the remediation of large contaminated areas that originate mostly from the legacy of the former U mining. As a general result of this comprehensive research project, a phytostabilization/ phytoextraction of such SM/R contaminated sites is feasible with a protection of ground water, and the plant crop from phytoremediation of the HM/R contaminated field site can be utilized for the winning of bioenergy (gaseous/ liquid products or thermal utilization). The beneficial combination of phytoremediation and subsequent utilization of the biomass can be further developed to an innovative and sustainable remediation technology with national and international application potential.

  3. Io Pele plume

    Science.gov (United States)

    2000-01-01

    Voyager 1 took this narrow-angle camera image on 5 March 1979 from a distance of 450,000 kilometers. At this geometry, the camera looks straight down through a volcanic plume at one of Io's most active volcanos, Pele. The large heart-shaped feature is the region where Pele's plume falls to the surface. At the center of the 'heart' is the small dark fissure that is the source of the eruption. The Voyager Project is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science.

  4. DOE's process and implementation guidance for decommissioning, deactivation, decontamination, and remedial action of property with residual contamination

    International Nuclear Information System (INIS)

    Domotor, S.; Peterson, H. Jr.; Wallo, A. III

    1999-01-01

    This paper presents DOE's requirements, process, and implementation guidance for the control and release of property that may contain residual radioactive material. DOE requires that criteria and protocols for release of property be approved by DOE and that such limits be selected using DOE's As Low as is Reasonably Achievable (ALARA) process. A DOE Implementation Guide discusses how the levels and details (e.g., cleanup volumes, costs of surveys, disposal costs, dose to workers and doses to members of the public, social and economic factors) of candidate release options are to be evaluated using DOE's ALARA process. Supporting tools and models for use within the analysis are also highlighted. (author)

  5. Dilution in Transition Zone between Rising Plumes and Surface Plumes

    DEFF Research Database (Denmark)

    Larsen, Torben

    2004-01-01

    The papers presents some physical experiments with the dilution of sea outfall plumes with emphasize on the transition zone where the relative fast flowing vertical plume turns to a horizontal surface plume following the slow sea surface currents. The experiments show that a considerable dilution...

  6. Biodegradation at Dynamic Plume Fringes: Mixing Versus Reaction Control

    Science.gov (United States)

    Cirpka, O. A.; Eckert, D.; Griebler, C.; Haberer, C.; Kürzinger, P.; Bauer, R.; Mellage, A.

    2014-12-01

    Biodegradation of continuously emitted plumes is known to be most pronounced at the plume fringe, where mixing of contaminated water and ambient groundwater, containing dissolved electron acceptors, stimulates microbial activity. Under steady-state conditions, physical mixing of contaminant and electron acceptor by transverse dispersion was shown to be the major bottleneck for biodegradation, with plume lengths scaling inversely with the bulk transverse dispersivity in quasi two-dimensional settings. Under these conditions, the presence of suitable microbes is essential but the biokinetic parameters do not play an important role. When the location of the plume shifts (caused, e.g., by a fluctuating groundwater table), however, the bacteria are no more situated at the plume fringe and biomass growth, decay, activation and deactivation determine the time lag until the fringe-controlled steady state is approached again. During this time lag, degradation is incomplete. The objective of the presented study was to analyze to which extent flow and transport dynamics diminish effectiveness of fringe-controlled biodegradation and which microbial processes and related biokinetic parameters determine the system response in overall degradation to hydraulic fluctuations. We performed experiments in quasi-two-dimensional flow through microcosms on aerobic toluene degradation by Pseudomonas putida F1. Plume dynamics were simulated by vertical alteration of the toluene plume position and experimental results were analyzed by reactive-transport modeling. We found that, even after disappearance of the toluene plume for two weeks, the majority of microorganisms stayed attached to the sediment and regained their full biodegradation potential within two days after reappearance of the toluene plume. Our results underline that besides microbial growth and maintenance (often subsumed as "biomass decay") microbial dormancy (that is, change into a metabolically inactive state) and

  7. Experiments on Plume Spreading by Engineered Injection and Extraction

    Science.gov (United States)

    Mays, D. C.; Jones, M.; Tigera, R. G.; Neupauer, R.

    2014-12-01

    The notion that groundwater remediation is transport-limited emphasizes the coupling between physical (i.e., hydrodynamic), geochemical, and microbiological processes in the subsurface. Here we leverage this coupling to promote groundwater remediation using the approach of engineered injection and extraction. In this approach, inspired by the literature on chaotic advection, uncontaminated groundwater is injected and extracted through a manifold of wells surrounding the contaminated plume. The potential of this approach lies in its ability to actively manipulate the velocity field near the contaminated plume, generating plume spreading above and beyond that resulting from aquifer heterogeneity. Plume spreading, in turn, promotes mixing and reaction by chemical and biological processes. Simulations have predicted that engineered injection and extraction generates (1) chaotic advection whose characteristics depend on aquifer heterogeneity, and (2) faster rates and increased extent of groundwater remediation. This presentation focuses on a complimentary effort to experimentally demonstrate these predictions experimentally. In preparation for future work using refractive index matched (RIM) porous media, the experiments reported here use a Hele-Shaw apparatus containing silicone oil. Engineered injection and extraction is used to manipulate the geometry of an initially circular plume of black pigment, and photographs record the plume geometry after each step of injection of extraction. Image analysis, using complimentary Eulerian and Lagrangian approaches, reveals the thickness and variability of the dispersion zone surrounding the deformed plume of black pigment. The size, shape, and evolution of this dispersion zone provides insight into the interplay between engineered injection and extraction, which generates plume structure, and dispersion (here Taylor dispersion), which destroys plume structure. These experiments lay the groundwork for application of engineered

  8. Survival, growth, and body residues of hyalella azteca (Saussure) exposed to fipronil contaminated sediments from non-vegetated and vegetated microcosms.

    Science.gov (United States)

    Kröger, Robert; Lizotte, Richard E; Moore, Matthew T

    2009-09-01

    We assessed chronic effects of fipronil and metabolite contaminated sediments from non-vegetated and Thallia dealbata vegetated wetland microcosms on Hyalella azteca during wet and dry exposures. Mean sediment concentrations (ng g(-1)) ranged from 0.72-1.26, 0.01-0.69, 0.07-0.23, and 0.49-7.87 for fipronil, fipronil-sulfide, fipronil-sulfone, and fipronil-desulfinyl, respectively. No significant differences in animal survival or growth were observed between non-vegetated and vegetated microcosms during wet or dry exposures. Mean animal body residue concentrations (ng g(-1)) ranged from 28.4-77.6, 0-30.7, and 8.3-43.8 for fipronil, fipronil-sulfide, and fipronil-sulfone. Fipronil-desulfinyl was not detected in any animal samples.

  9. INDEPENDENT TECHNICAL REVIEW OF THE BUILDING 100 PLUME, FORMER DOE PINELLAS SITE (YOUNG - RAINEY STAR CENTER), LARGO, FLORIDA

    Energy Technology Data Exchange (ETDEWEB)

    Eddy-Dilek, C.; Rossabi, J.; Amidon, M.; Riha, B.; Kaback, D.

    2010-07-30

    and/or bioaugmentation to provide a sustainable remediation system within the flow path of the plume. Additional data will be required to implement this approach and will include: (1) Better delineation of the nature and extent of contamination; (2) Demonstration the plume is currently stable or shrinking; and (3) Demonstration the full reductive dechlorination is occurring. The technical team recommends that DOE use a phased approach to identify residual contamination and to provide rapid installation of remedies. Matrices of characterization and remediation sensors, technologies, and tools were developed by the team in order to match the specific conditions and requirements of the site. The team provides a specific example of remedy that includes the incorporation of a dynamic characterization strategy moving from minimally invasive to more aggressive field techniques, the consideration of multiple complementary remediation approaches based on a spatiotemporally phased approach keyed to the different demands of different parts of the plume, and the integration and sequencing of the characterization and remediation activities.

  10. Residues of legacy organochlorine contaminants in the milk of Alpine and Saanen goats from the central region of Mexico.

    Science.gov (United States)

    Schettino, Beatriz; Gutiérrez, Rey; Ortiz, Rutilio; Vega, Salvador; Urban, Georgina; Ramírez, Acacia

    2013-08-01

    This study investigated a suite of legacy organochlorine contaminants in the milk of two breeds of goats raised in the central region of Mexico, where this agricultural production is of national (Mexican) economic importance. Forty milk samples from Alpine and Saanen goats were assessed. It was found that the concentrations of the majority of organochlorine pesticides in milk samples were lower than those stipulated in Mexican and international regulation. The values in both breeds of goat exceeded the upper permissible limits of Codex Alimentarius for delta hexachloro cyclohexane (HCH) (17.3 of samples of Saanen) and heptachlor plus heptachlor epoxide (50 % and 13 % of samples). It may be concluded that milk from these goat breeds from central Mexico showed some risks of contamination in certain times of the year (dry season). However, under further assessment and use of pesticides the goat's milk will likely be safe for human consumption and for use in products such as cheeses, regional candies and desserts (cajeta). In recent years, goat milk production has increased in the central regions and it is an economic alternative to milk from livestock. It is necessary to continue the monitoring of goat's milk to assess the presence and control of HCHs through best management practices.

  11. On predicting mantle mushroom plumes

    Directory of Open Access Journals (Sweden)

    Ka-Kheng Tan

    2011-04-01

    Top cooling may produce plunging plumes of diameter of 585 km and at least 195 Myr old. The number of cold plumes is estimated to be 569, which has not been observed by seismic tomography or as cold spots. The cold plunging plumes may overwhelm and entrap some of the hot rising plumes from CMB, so that together they may settle in the transition zone.

  12. Turbulent buoyant jets and plumes

    CERN Document Server

    Rodi, Wolfgang

    The Science & Applications of Heat and Mass Transfer: Reports, Reviews, & Computer Programs, Volume 6: Turbulent Buoyant Jets and Plumes focuses on the formation, properties, characteristics, and reactions of turbulent jets and plumes. The selection first offers information on the mechanics of turbulent buoyant jets and plumes and turbulent buoyant jets in shallow fluid layers. Discussions focus on submerged buoyant jets into shallow fluid, horizontal surface or interface jets into shallow layers, fundamental considerations, and turbulent buoyant jets (forced plumes). The manuscript then exami

  13. PLUME and research sotware

    Science.gov (United States)

    Baudin, Veronique; Gomez-Diaz, Teresa

    2013-04-01

    The PLUME open platform (https://www.projet-plume.org) has as first goal to share competences and to value the knowledge of software experts within the French higher education and research communities. The project proposes in its platform the access to more than 380 index cards describing useful and economic software for this community, with open access to everybody. The second goal of PLUME focuses on to improve the visibility of software produced by research laboratories within the higher education and research communities. The "development-ESR" index cards briefly describe the main features of the software, including references to research publications associated to it. The platform counts more than 300 cards describing research software, where 89 cards have an English version. In this talk we describe the theme classification and the taxonomy of the index cards and the evolution with new themes added to the project. We will also focus on the organisation of PLUME as an open project and its interests in the promotion of free/open source software from and for research, contributing to the creation of a community of shared knowledge.

  14. Buoyant plume calculations

    International Nuclear Information System (INIS)

    Penner, J.E.; Haselman, L.C.; Edwards, L.L.

    1985-01-01

    Smoke from raging fires produced in the aftermath of a major nuclear exchange has been predicted to cause large decreases in surface temperatures. However, the extent of the decrease and even the sign of the temperature change, depend on how the smoke is distributed with altitude. We present a model capable of evaluating the initial distribution of lofted smoke above a massive fire. Calculations are shown for a two-dimensional slab version of the model and a full three-dimensional version. The model has been evaluated by simulating smoke heights for the Hamburg firestorm of 1943 and a smaller scale oil fire which occurred in Long Beach in 1958. Our plume heights for these fires are compared to those predicted by the classical Morton-Taylor-Turner theory for weakly buoyant plumes. We consider the effect of the added buoyancy caused by condensation of water-laden ground level air being carried to high altitude with the convection column as well as the effects of background wind on the calculated smoke plume heights for several fire intensities. We find that the rise height of the plume depends on the assumed background atmospheric conditions as well as the fire intensity. Little smoke is injected into the stratosphere unless the fire is unusually intense, or atmospheric conditions are more unstable than we have assumed. For intense fires significant amounts of water vapor are condensed raising the possibility of early scavenging of smoke particles by precipitation. 26 references, 11 figures

  15. Stabilization of in-tank residual wastes and external tank soil contamination for the Hanford tank closure program: application to the AX tank farm

    Energy Technology Data Exchange (ETDEWEB)

    SONNICHSEN, J.C.

    1998-10-12

    Mixed high-level waste is currently stored in underground tanks at the US Department of Energy's (DOE's) Hanford Site. The plan is to retrieve the waste, process the water, and dispose of the waste in a manner that will provide less long-term health risk. The AX Tank Farm has been identified for purposes of demonstration. Not all the waste can be retrieved from the tanks and some waste has leaked from these tanks into the underlying soil. Retrieval of this waste could result in additional leakage. During FY1998, the Sandia National Laboratory was under contract to evaluate concepts for immobilizing the residual waste remaining in tanks and mitigating the migration of contaminants that exist in the soil column. Specifically, the scope of this evaluation included: development of a layered tank fill design for reducing water infiltration; development of in-tank getter technology; mitigation of soil contamination through grouting; sequestering of specific radionuclides in soil; and geochemical and hydrologic modeling of waste-water-soil interactions. A copy of the final report prepared by Sandia National Laboratory is attached.

  16. Dry decontamination technology development for high radioactive contaminant application - Development of residual radiation assessment methodology for high radioactive facility decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Lee, G. J.; Hong, D. S.; Jeong, H. Y. [Korea Advanced Institute of Science and Technology, Taejon (Korea)

    2000-04-01

    Humidity around the concrete structure can make the moisture distribution within the concrete. Moisture content of the structure will change due to the diffusion process with time. Radioactive material on the surface of concrete will eventually diffuse into the porous concrete and contaminates the internal region of the concrete. In this study, we have assumed two different diffusion processes depending on the different moisture content. One is for slow diffusion process near the surface and the other is for fast diffusion process in deep region. We have developed the mathematical diffusion model for the two different diffusion regions and the corresponding analytic solutions for the two regions are obtained. 19 refs., 15 figs., 9 tabs. (Author)

  17. Integration of processes induced air flotation and photo-Fenton for treatment of residual waters contaminated with xylene

    International Nuclear Information System (INIS)

    Silva, Syllos S. da; Chiavone-Filho, Osvaldo; Barros Neto, Eduardo L. de; Nascimento, Claudio A.O.

    2012-01-01

    Highlights: ► We have studied the treatment of wastewater contaminated with hydrocarbons represented by the xylene, using these processes in an integrated mode: induced air flotation and photo-Fenton. ► We have selected xylene as representative contaminant due to properties of toxicity, solubility in water and vapor pressure. ► The manuscript presents a series of accurate experimental data that can be useful for material and energy optimization purposes in the xylene removal aiming the treatment of oil field produced water. - Abstract: Produced water in oil fields is one of the main sources of wastewater generated in the industry. It contains several organic compounds, such as benzene, toluene, ethyl benzene and xylene (BTEX), whose disposal is regulated by law. The aim of this study is to investigate a treatment of produced water integrating two processes, i.e., induced air flotation (IAF) and photo-Fenton. The experiments were conducted in a column flotation and annular lamp reactor for flotation and photodegradation steps, respectively. The first order kinetic constant of IAF for the wastewater studied was determined to be 0.1765 min −1 for the surfactant EO 7. Degradation efficiencies of organic loading were assessed using factorial planning. Statistical data analysis shows that H 2 O 2 concentration is a determining factor in process efficiency. Degradations above 90% were reached in all cases after 90 min of reaction, attaining 100% mineralization in the optimized concentrations of Fenton reagents. Process integration was adequate with 100% organic load removal in 20 min. The results of the integration of the IAF with the photo-Fenton allowed to meet the effluent limits established by Brazilian legislation for disposal.

  18. Integration of processes induced air flotation and photo-Fenton for treatment of residual waters contaminated with xylene

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Syllos S. da [Departamento Engenharia Quimica, NUPEG, Universidade Federal do Rio Grande do Norte, Campus Universitario, Lagoa Nova, Natal 59066-800, RN (Brazil); Chiavone-Filho, Osvaldo, E-mail: osvaldo@eq.ufrn.br [Departamento Engenharia Quimica, NUPEG, Universidade Federal do Rio Grande do Norte, Campus Universitario, Lagoa Nova, Natal 59066-800, RN (Brazil); Barros Neto, Eduardo L. de [Departamento Engenharia Quimica, NUPEG, Universidade Federal do Rio Grande do Norte, Campus Universitario, Lagoa Nova, Natal 59066-800, RN (Brazil); Nascimento, Claudio A.O. [Departamento de Engenharia Quimica, Escola Politecnica, Universidade de Sao Paulo, Cidade Universitaria, Sao Paulo 05508-900, SP (Brazil)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer We have studied the treatment of wastewater contaminated with hydrocarbons represented by the xylene, using these processes in an integrated mode: induced air flotation and photo-Fenton. Black-Right-Pointing-Pointer We have selected xylene as representative contaminant due to properties of toxicity, solubility in water and vapor pressure. Black-Right-Pointing-Pointer The manuscript presents a series of accurate experimental data that can be useful for material and energy optimization purposes in the xylene removal aiming the treatment of oil field produced water. - Abstract: Produced water in oil fields is one of the main sources of wastewater generated in the industry. It contains several organic compounds, such as benzene, toluene, ethyl benzene and xylene (BTEX), whose disposal is regulated by law. The aim of this study is to investigate a treatment of produced water integrating two processes, i.e., induced air flotation (IAF) and photo-Fenton. The experiments were conducted in a column flotation and annular lamp reactor for flotation and photodegradation steps, respectively. The first order kinetic constant of IAF for the wastewater studied was determined to be 0.1765 min{sup -1} for the surfactant EO 7. Degradation efficiencies of organic loading were assessed using factorial planning. Statistical data analysis shows that H{sub 2}O{sub 2} concentration is a determining factor in process efficiency. Degradations above 90% were reached in all cases after 90 min of reaction, attaining 100% mineralization in the optimized concentrations of Fenton reagents. Process integration was adequate with 100% organic load removal in 20 min. The results of the integration of the IAF with the photo-Fenton allowed to meet the effluent limits established by Brazilian legislation for disposal.

  19. Ameliorating Effects of Bacillus subtilis ANSB060 on Growth Performance, Antioxidant Functions, and Aflatoxin Residues in Ducks Fed Diets Contaminated with Aflatoxins

    Directory of Open Access Journals (Sweden)

    Liyuan Zhang

    2016-12-01

    Full Text Available Bacillus subtilis ANSB060 isolated from fish gut is very effective in detoxifying aflatoxins in feed and feed ingredients. The purpose of this research was to investigate the effects of B. subtilis ANSB060 on growth performance, body antioxidant functions, and aflatoxin residues in ducks fed moldy maize naturally contaminated with aflatoxins. A total of 1500 18-d-old male Cherry Valley ducks with similar body weight were randomly assigned to five treatments with six replicates of 50 ducks per repeat. The experiment design consisted of five dietary treatments labeled as C0 (basal diet containing 60% normal maize, M0 (basal diet containing 60% moldy maize contaminated with aflatoxins substituted for normal maize, M500, M1000, and M2000 (M0 +500, 1000 or 2000 g/t aflatoxin biodegradation preparation mainly consisted of B. subtilis ANSB060. The results showed that ducks fed 22.44 ± 2.46 μg/kg of AFB1 (M0 exhibited a decreasing tendency in average daily gain (ADG and total superoxide dismutase (T-SOD activity in serum, and T-SOD and glutathione peroxidase (GSH-Px activities in the liver significantly decreased along with the appearance of AFB1 and AFM1 compared with those in Group C0. The supplementation of B. subtilis ANSB060 into aflatoxin-contaminated diets increased the ADG of ducks (p > 0.05, significantly improved antioxidant enzyme activities, and reduced aflatoxin accumulation in duck liver. In conclusion, Bacillus subtilis ANSB060 in diets showed an ameliorating effect to duck aflatoxicosis and may be a promising feed additive.

  20. Ameliorating Effects of Bacillus subtilis ANSB060 on Growth Performance, Antioxidant Functions, and Aflatoxin Residues in Ducks Fed Diets Contaminated with Aflatoxins.

    Science.gov (United States)

    Zhang, Liyuan; Ma, Qiugang; Ma, Shanshan; Zhang, Jianyun; Jia, Ru; Ji, Cheng; Zhao, Lihong

    2016-12-22

    Bacillus subtilis ANSB060 isolated from fish gut is very effective in detoxifying aflatoxins in feed and feed ingredients. The purpose of this research was to investigate the effects of B. subtilis ANSB060 on growth performance, body antioxidant functions, and aflatoxin residues in ducks fed moldy maize naturally contaminated with aflatoxins. A total of 1500 18-d-old male Cherry Valley ducks with similar body weight were randomly assigned to five treatments with six replicates of 50 ducks per repeat. The experiment design consisted of five dietary treatments labeled as C0 (basal diet containing 60% normal maize), M0 (basal diet containing 60% moldy maize contaminated with aflatoxins substituted for normal maize), M500, M1000, and M2000 (M0 +500, 1000 or 2000 g/t aflatoxin biodegradation preparation mainly consisted of B. subtilis ANSB060). The results showed that ducks fed 22.44 ± 2.46 μg/kg of AFB₁ (M0) exhibited a decreasing tendency in average daily gain (ADG) and total superoxide dismutase (T-SOD) activity in serum, and T-SOD and glutathione peroxidase (GSH-Px) activities in the liver significantly decreased along with the appearance of AFB₁ and AFM₁ compared with those in Group C0. The supplementation of B. subtilis ANSB060 into aflatoxin-contaminated diets increased the ADG of ducks ( p > 0.05), significantly improved antioxidant enzyme activities, and reduced aflatoxin accumulation in duck liver. In conclusion, Bacillus subtilis ANSB060 in diets showed an ameliorating effect to duck aflatoxicosis and may be a promising feed additive.

  1. Studies by nuclear and physico-chemical methods of tissue's metallic contamination located around biomaterials. Toxicity measurements of several biomaterials residual radioactivity

    International Nuclear Information System (INIS)

    Guibert, Geoffroy

    2004-01-01

    Implants used as biomaterials fulfill conditions of functionality, compatibility and occasionally bio-activity. There are four main families of biomaterials: metals and metal alloys, polymers, bio-ceramics and natural materials. Because of corrosion and friction in the human body, implants generate debris. These debris develop different problems: toxicity, inflammatory reactions, prosthetic unsealing by osseous dissolution. Nature, size, morphology and amount of debris are the parameters which have an influence on tissue response. We characterize metallic contamination coming from knee prosthesis into surrounding capsular tissue by depth migration, in vivo behaviours, content, size and nature of debris. The PIXE-RBS and STEM-EDXS methods, that we used, are complementary, especially about characterization scale. Debris contamination distributed in the whole articulation is very heterogeneous. Debris migrate on several thousands μm in tissue. Solid metallic particles, μm, are found in the most polluted samples, for both kinds of alloys TA6V and CrCoMo. In the mean volume analysed by PIXE, the in vivo mass ratios [Ti]/[V] and [Co]/[Cr] confirm the chemical stability of TA6V debris and chemical evolution of CrCoMo debris. Complementary measures of TA6V grains, on a nano-metric scale by STEM-EDXS, show a dissolution of coarse grain (μm) in smaller grains (nm). Locally, TA6V grains of a phase are detected and could indicate a preferential dissolution of β phase (grain boundaries) with dropping of Al and V, both toxic and carcinogenic elements. A thin target protocol development correlates PIXE and histological analysis on the same zone. This protocol allows to locate other pathologies in relationship with weaker metal contamination, μg/g, thanks to the great sensitivity of PIXE method. Harmlessness with respect to the residual radioactivity of several natural or synthetic biomaterials is established, using ultra low background noise γ detection system. (author)

  2. Risk element immobilization/stabilization potential of fungal-transformed dry olive residue and arbuscular mycorrhizal fungi application in contaminated soils.

    Science.gov (United States)

    García-Sánchez, Mercedes; Stejskalová, Tereza; García-Romera, Inmaculada; Száková, Jiřina; Tlustoš, Pavel

    2017-10-01

    The use of biotransformed dry olive residue (DOR) as organic soil amendment has recently been proposed due to its high contents of stabilized organic matter and nutrients. The potential of biotransformed DOR to immobilize risk elements in contaminated soils might qualify DOR as a potential risk element stabilization agent for in situ soil reclamation practices. In this experiment, the mobility of risk elements in response to Penicillium chrysogenum-10-transformed DOR, Funalia floccosa-transformed DOR, Bjerkandera adusta-transformed DOR, and Chondrostereum purpureum-transformed DOR as well as arbuscular mycorrhizal fungi (AMF), Funneliformis mosseae, inoculation was investigated. We evaluated the effect of these treatments on risk element uptake by wheat (Triticum aestivum L.) plants in a pot experiment with Cd, Pb, and Zn contaminated soil. The results showed a significant impact of the combined treatment (biotransformed DOR and AMF inoculation) on wheat plant growth and element mobility. The mobile proportions of elements in the treated soils were related to soil pH; with increasing pH levels, Cd, Cu, Fe, Mn, P, Pb, and Zn mobility decreased significantly (r values between -0.36 and -0.46), while Ca and Mg mobility increased (r = 0.63, and r = 0.51, respectively). The application of biotransformed DOR decreased risk element levels (Cd, Zn), and nutrient concentrations (Ca, Cu, Fe, Mg, Mn) in the aboveground biomass, where the elements were retained in the roots. Thus, biotransformed DOR in combination with AMF resulted in a higher capacity of wheat plants to grow under detrimental conditions, being able to accumulate high amounts of risk elements in the roots. However, risk element reduction was insufficient for safe crop production in the extremely contaminated soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Volcanic Plume Measurements with UAV (Invited)

    Science.gov (United States)

    Shinohara, H.; Kaneko, T.; Ohminato, T.

    2013-12-01

    Volatiles in magmas are the driving force of volcanic eruptions and quantification of volcanic gas flux and composition is important for the volcano monitoring. Recently we developed a portable gas sensor system (Multi-GAS) to quantify the volcanic gas composition by measuring volcanic plumes and obtained volcanic gas compositions of actively degassing volcanoes. As the Multi-GAS measures variation of volcanic gas component concentrations in the pumped air (volcanic plume), we need to bring the apparatus into the volcanic plume. Commonly the observer brings the apparatus to the summit crater by himself but such measurements are not possible under conditions of high risk of volcanic eruption or difficulty to approach the summit due to topography etc. In order to overcome these difficulties, volcanic plume measurements were performed by using manned and unmanned aerial vehicles. The volcanic plume measurements by manned aerial vehicles, however, are also not possible under high risk of eruption. The strict regulation against the modification of the aircraft, such as installing sampling pipes, also causes difficulty due to the high cost. Application of the UAVs for the volcanic plume measurements has a big advantage to avoid these problems. The Multi-GAS consists of IR-CO2 and H2O gas analyzer, SO2-H2O chemical sensors and H2 semiconductor sensor and the total weight ranges 3-6 kg including batteries. The necessary conditions of the UAV for the volcanic plumes measurements with the Multi-GAS are the payloads larger than 3 kg, maximum altitude larger than the plume height and installation of the sampling pipe without contamination of the exhaust gases, as the exhaust gases contain high concentrations of H2, SO2 and CO2. Up to now, three different types of UAVs were applied for the measurements; Kite-plane (Sky Remote) at Miyakejima operated by JMA, Unmanned airplane (Air Photo Service) at Shinomoedake, Kirishima volcano, and Unmanned helicopter (Yamaha) at Sakurajima

  4. Chernobyl plume: commentary about a discharge

    International Nuclear Information System (INIS)

    Anon

    2011-01-01

    The Paris appeal court has dismissed the charges against P. Pellerin who was the head of the SCIRP (service of protection against the ionizing radiations) at the time of the Chernobyl accident. The appeal court confirms that P.Pellerin never said that the Chernobyl plume stopped at the French border but instead he said that the Chernobyl plume entered the French territory but the radioactivity level was so low that it was unnecessary to take sanitary steps. P.Pellerin based his decision on the results of 6500 controls performed by the SCIRP in May and June 1986. Seven other European countries recommended not to take sanitary measures. The increase of thyroid cancers that has happened in all industrialized countries and that affect only adults, can not due to Chernobyl contamination because child's thyroid is far more sensitive than adult's. The increase of thyroid cancer is mainly due to a better detection of the tumors. (A.C.)

  5. Método da eletrorresistividade aplicado no monitoramento temporal da pluma de contaminação em área de disposição de resíduos sólidos urbanos Electrical resistivity method applied in the temporal monitoring of the contamination plume in disposal area of urban solid waste

    Directory of Open Access Journals (Sweden)

    José Ricardo Melges Bortolin

    2010-12-01

    Full Text Available Este trabalho apresenta os resultados do monitoramento temporal da pluma de contaminação do aterro controlado de Rio Claro, São Paulo, por meio do método da eletrorresistividade, que consistiu na comparação dos resultados de várias seções de imageamento elétrico, executados nos mesmo locais, nos anos de 1999 e 2008. Zonas de baixa resistividade, com valores menores ou iguais a 50 Ω.m, foram associadas à contaminação por chorume. Desse modo, foi possível identificar dois sentidos do fluxo da pluma: (1 em direção ao sul, e (2 em direção ao oeste. Nas seções de 2008, a pluma de contaminação apresentou-se mais extensa e profunda do que em 1999. De forma complementar, as sondagens elétricas verticais aferiram a profundidade do nível freático e o sentido do fluxo d'água, subsidiando a interpretação dos imageamentos.This paper shows the results of a periodical monitoring of the contamination plume of a controlled landfill in Rio Claro, São Paulo, Brazil, using electrical resistivity geophysical method. The monitoring consisted on comparing the results of several electrical sections, performed at the same location, in the years of 1999 and 2008. Low resistivity zones, with values lower than or equal to 50 Ω.m, have been associated to contamination by leachate. Thus, it was possible to identify two directions for the contamination flows: (1 toward south, and (2 toward west. In the results of 2008, the contamination plume was more extensive and profound than in 1999. The vertical electrical soundings indicated the water table depth and the water flow directions, helping the interpretation of results of the electrical profiles.

  6. Occurrence of Natural Bacillus thuringiensis Contaminants and Residues of Bacillus thuringiensis-Based Insecticides on Fresh Fruits and Vegetables

    Science.gov (United States)

    Frederiksen, Kristine; Rosenquist, Hanne; Jørgensen, Kirsten; Wilcks, Andrea

    2006-01-01

    A total of 128 Bacillus cereus-like strains isolated from fresh fruits and vegetables for sale in retail shops in Denmark were characterized. Of these strains, 39% (50/128) were classified as Bacillus thuringiensis on the basis of their content of cry genes determined by PCR or crystal proteins visualized by microscopy. Random amplified polymorphic DNA analysis and plasmid profiling indicated that 23 of the 50 B. thuringiensis strains were of the same subtype as B. thuringiensis strains used as commercial bioinsecticides. Fourteen isolates were indistinguishable from B. thuringiensis subsp. kurstaki HD1 present in the products Dipel, Biobit, and Foray, and nine isolates grouped with B. thuringiensis subsp. aizawai present in Turex. The commercial strains were primarily isolated from samples of tomatoes, cucumbers, and peppers. A multiplex PCR method was developed to simultaneously detect all three genes in the enterotoxin hemolysin BL (HBL) and the nonhemolytic enterotoxin (NHE), respectively. This revealed that the frequency of these enterotoxin genes was higher among the strains indistinguishable from the commercial strains than among the other B. thuringiensis and B. cereus-like strains isolated from fruits and vegetables. The same was seen for a third enterotoxin, CytK. In conclusion, the present study strongly indicates that residues of B. thuringiensis-based insecticides can be found on fresh fruits and vegetables and that these are potentially enterotoxigenic. PMID:16672488

  7. EDDS and EDTA-enhanced phytoextraction of metals from artificially contaminated soil and residual effects of chelant compounds

    Energy Technology Data Exchange (ETDEWEB)

    Luo Chunling [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Shen Zhenguo [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Lou Laiqing [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Li Xiangdong [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)]. E-mail: cexdli@polyu.edu.hk

    2006-12-15

    The potential of 18 different plants to be used in the chemically enhanced phytoextraction of Cu, Pb, Zn and Cd was assessed using pot experiments. Chrysanthemum coronarium L. was the species most sensitive to the application of EDTA, and had the highest enhancement of Cu and Pb concentrations in its shoots. Compared with EDTA, EDDS was more effective in enhancing the concentration of Cu in the shoots of Chrysanthemum coronarium L. and Zea mays L. grown on multi-metal contaminated soils. The EDTA-treated soil still had a significant ability to enhance the concentrations of Cu and Pb in the shoots of Zea mays L. six months after the chelant treatment. However, the EDDS-treated soil did not have any effect in enhancing the concentrations of metals in the shoots of Zea mays L. in the second crop test. The results may indicate that EDDS biodegrades more rapidly than EDTA in soil and is better in limiting potential metal leaching. - Chrysanthemum coronarium L. was the most sensitive species to the application of chelants, and EDDS biodegrades much more rapidly than EDTA in soil.

  8. EDDS and EDTA-enhanced phytoextraction of metals from artificially contaminated soil and residual effects of chelant compounds

    International Nuclear Information System (INIS)

    Luo Chunling; Shen Zhenguo; Lou Laiqing; Li Xiangdong

    2006-01-01

    The potential of 18 different plants to be used in the chemically enhanced phytoextraction of Cu, Pb, Zn and Cd was assessed using pot experiments. Chrysanthemum coronarium L. was the species most sensitive to the application of EDTA, and had the highest enhancement of Cu and Pb concentrations in its shoots. Compared with EDTA, EDDS was more effective in enhancing the concentration of Cu in the shoots of Chrysanthemum coronarium L. and Zea mays L. grown on multi-metal contaminated soils. The EDTA-treated soil still had a significant ability to enhance the concentrations of Cu and Pb in the shoots of Zea mays L. six months after the chelant treatment. However, the EDDS-treated soil did not have any effect in enhancing the concentrations of metals in the shoots of Zea mays L. in the second crop test. The results may indicate that EDDS biodegrades more rapidly than EDTA in soil and is better in limiting potential metal leaching. - Chrysanthemum coronarium L. was the most sensitive species to the application of chelants, and EDDS biodegrades much more rapidly than EDTA in soil

  9. Safety analysis of occupational exposure of healthcare workers to residual contaminations of cytotoxic drugs using FMECA security approach.

    Science.gov (United States)

    Le, Laetitia Minh Mai; Reitter, Delphine; He, Sophie; Bonle, Franck Té; Launois, Amélie; Martinez, Diane; Prognon, Patrice; Caudron, Eric

    2017-12-01

    Handling cytotoxic drugs is associated with chemical contamination of workplace surfaces. The potential mutagenic, teratogenic and oncogenic properties of those drugs create a risk of occupational exposure for healthcare workers, from reception of starting materials to the preparation and administration of cytotoxic therapies. The Security Failure Mode Effects and Criticality Analysis (FMECA) was used as a proactive method to assess the risks involved in the chemotherapy compounding process. FMECA was carried out by a multidisciplinary team from 2011 to 2016. Potential failure modes of the process were identified based on the Risk Priority Number (RPN) that prioritizes corrective actions. Twenty-five potential failure modes were identified. Based on RPN results, the corrective actions plan was revised annually to reduce the risk of exposure and improve practices. Since 2011, 16 specific measures were implemented successively. In six years, a cumulative RPN reduction of 626 was observed, with a decrease from 912 to 286 (-69%) despite an increase of cytotoxic compounding activity of around 23.2%. In order to anticipate and prevent occupational exposure, FMECA is a valuable tool to identify, prioritize and eliminate potential failure modes for operators involved in the cytotoxic drug preparation process before the failures occur. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Solid residues

    International Nuclear Information System (INIS)

    Mulder, E.; Duin, P.J. van; Grootenboer, G.J.

    1995-01-01

    A summary is presented of the many investigations that have been done on solid residues of atmospheric fluid bed combustion (AFBC). These residues are bed ash, cyclone ash and bag filter ash. Physical and chemical properties are discussed and then the various uses of residues (in fillers, bricks, gravel, and for recovery of aluminium) are summarised. Toxicological properties of fly ash and stack ash are discussed as are risks of pneumoconiosis for workers handling fly ash, and contamination of water by ashes. On the basis of present information it is concluded that risks to public health from exposure to emissions of coal fly ash from AFBC appear small or negligible as are health risk to workers in the coal fly ash processing industry. 35 refs., 5 figs., 12 tabs

  11. Evaluation of natural attenuation processes for trichloroethylene and technetium-99 in the Northeast and Northwest plumes at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    International Nuclear Information System (INIS)

    Clausen, J.L.; Sturchio, N.C.; Heraty, L.J.; Huang, L.; Abrajano, T.

    1997-01-01

    NA processes such as biodegradation, sorption, dilution dispersion, advection, and possibly sorption and diffusion are occurring in the Northeast and Northwest plumes. However, the overall biological attenuation rate for TCE within the plumes is not sufficiently rapid to utilize as remedial option. The mobility and toxicity of 99 Tc is not being reduced by attenuating processes within the Northwest Plume. The current EPA position is that NA is not a viable remedial approach unless destructive processes are present or processes are active which reduce the toxicity and mobility of a contaminant. Therefore, active remediation of the dissolved phase plumes will be necessary to reduce contaminant concentrations before an NA approach could be justified at PGDP for either plume. Possible treatment methods for the reduction of dissolved phase concentrations within the plumes are pump-and-treat bioaugmentation, biostimulation, or multiple reactive barriers. Another possibility is the use of a regulatory instrument such as an Alternate Concentration Limit (ACL) petition. Biodegradation of TCE is occurring in both plumes and several hypothesis are possible to explain the apparent conflicts with some of the geochemical data. The first hypothesis is active intrinsic bioremediation is negligible or so slow to be nonmeasurable. In this scenario, the D.O., chloride, TCE, and isotopic results are indicative of past microbiological reactions. It is surmised in this scenario, that when the initial TCE release occurred, sufficient energy sources were available for microorganisms to drive aerobic reduction of TCE, but these energy sources were rapidly depleted. The initial degraded TCE has since migrated to downgradient locations. In the second scenario, TCE anaerobic degradation occurs in organic-rich micro-environments within a generally aerobic aquifer. TCE maybe strongly absorbed to organic-rich materials in the aquifer matrix and degraded by local Immunities of microbes, perhaps

  12. Evaluation of natural attenuation processes for trichloroethylene and technetium-99 in the Northeast and Northwest plumes at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    Clausen, J.L.; Sturchio, N.C.; Heraty, L.J.; Huang, L.; Abrajano,T.

    1997-11-25

    NA processes such as biodegradation, sorption, dilution dispersion, advection, and possibly sorption and diffusion are occurring in the Northeast and Northwest plumes. However, the overall biological attenuation rate for TCE within the plumes is not sufficiently rapid to utilize as remedial option. The mobility and toxicity of {sup 99}Tc is not being reduced by attenuating processes within the Northwest Plume. The current EPA position is that NA is not a viable remedial approach unless destructive processes are present or processes are active which reduce the toxicity and mobility of a contaminant. Therefore, active remediation of the dissolved phase plumes will be necessary to reduce contaminant concentrations before an NA approach could be justified at PGDP for either plume. Possible treatment methods for the reduction of dissolved phase concentrations within the plumes are pump-and-treat bioaugmentation, biostimulation, or multiple reactive barriers. Another possibility is the use of a regulatory instrument such as an Alternate Concentration Limit (ACL) petition. Biodegradation of TCE is occurring in both plumes and several hypothesis are possible to explain the apparent conflicts with some of the geochemical data. The first hypothesis is active intrinsic bioremediation is negligible or so slow to be nonmeasurable. In this scenario, the D.O., chloride, TCE, and isotopic results are indicative of past microbiological reactions. It is surmised in this scenario, that when the initial TCE release occurred, sufficient energy sources were available for microorganisms to drive aerobic reduction of TCE, but these energy sources were rapidly depleted. The initial degraded TCE has since migrated to downgradient locations. In the second scenario, TCE anaerobic degradation occurs in organic-rich micro-environments within a generally aerobic aquifer. TCE maybe strongly absorbed to organic-rich materials in the aquifer matrix and degraded by local Immunities of microbes

  13. Selective dissolution followed by EDDS washing of an e-waste contaminated soil: Extraction efficiency, fate of residual metals, and impact on soil environment.

    Science.gov (United States)

    Beiyuan, Jingzi; Tsang, Daniel C W; Valix, Marjorie; Zhang, Weihua; Yang, Xin; Ok, Yong Sik; Li, Xiang-Dong

    2017-01-01

    To enhance extraction of strongly bound metals from oxide minerals and organic matter, this study examined the sequential use of reductants, oxidants, alkaline solvents and organic acids followed by a biodegradable chelating agent (EDDS, [S,S]-ethylene-diamine-disuccinic-acid) in a two-stage soil washing. The soil was contaminated by Cu, Zn, and Pb at an e-waste recycling site in Qingyuan city, China. In addition to extraction efficiency, this study also examined the fate of residual metals (e.g., leachability, bioaccessibility, and distribution) and the soil quality parameters (i.e., cytotoxicity, enzyme activities, and available nutrients). The reductants (dithionite-citrate-bicarbonate and hydroxylamine hydrochloride) effectively extracted metals by mineral dissolution, but elevated the leachability and bioaccessibility of metals due to the transformation from Fe/Mn oxides to labile fractions. Subsequent EDDS washing was found necessary to mitigate the residual risks. In comparison, prior washing by oxidants (persulphate, hypochlorite, and hydrogen peroxide) was marginally useful because of limited amount of soil organic matter. Prior washing by alkaline solvents (sodium hydroxide and sodium bicarbonate) was also ineffective due to metal precipitation. In contrast, prior washing by low-molecular-weight organic acids (citrate and oxalate) improved the extraction efficiency. Compared to hydroxylamine hydrochloride, citrate and oxalate induced lower cytotoxicity (Microtox) and allowed higher enzyme activities (dehydrogenase, acid phosphatase, and urease) and soil nutrients (available nitrogen and phosphorus), which would facilitate reuse of the treated soil. Therefore, while sequential washing proved to enhance extraction efficacy, the selection of chemical agents besides EDDS should also include the consideration of effects on metal leachability/bioaccessibility and soil quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Thermal plumes in ventilated rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    1990-01-01

    The design of a displacement ventilation system involves determination of the flow rate in the thermal plumes. The flow rate in the plumes and the vertical temperature gradient influence each other, and they are influenced by many factors. This paper shows some descriptions of these effects. Free...... above a point heat source cannot be used. This is caused either by the way of generating the plume including a long intermediate region or by the environmental conditions where vertical temperature gradients are present. The flow has a larger angle of spread and the entrainment factor is greather than...... turbulent plumes from different heated bodies are investigated. The measurements have taken place in a full-scale test room where the vertical temperature gradient have been changed. The velocity and the temperature distribution in the plume are measured. Large scale plume axis wandering is taken...

  15. Bioaccessible Porosity: A new approach to assess residual contamination after bioremediation of hydrophobic organic compounds in sub-surface microporous environments

    Science.gov (United States)

    Akbari, A.; Ghoshal, S.

    2016-12-01

    We define a new parameter, "bioaccessible porosity", the fraction of aggregate volume accessible to soil bacteria, towards a priori assessment of hydrocarbon bioremediation end points. Microbial uptake of poorly soluble hydrocarbons occurs through direct uptake or micellar solubilzation/emulsification associated with biosurfactant production, and requires close proximity of bacteria and hydrocarbon phase. In subsurface microporous environments, bioremediation rates are attenuated when residual hydrophobic contamination is entrapped in sterically restrictive environments which is not accessible to soil bacteria. This study presents new approaches for characterization of the microstructure of porous media and as well, the ability of indigenous hydrocarbon degraders to access to a range of pore sizes. Bacterial access to poorly soluble hydrocarbons in soil micro pores were simulated with bioreactors with membranes with different pore sizes containing the hydrocarbon degrading bacteria, Dietzia maris. D. maris is Gram-positive, and nonmotile that we isolated as the major hydrocarbon degrader from a fine-grained, weathered, hydrocarbon-contaminated site soil. Under nutritional stress, planktonic D. maris cells were aggregated and accessed 5 µm but not 3 µm and smaller pores. However, when hexadecane was available at the pore mouth, D. maris colonized the pore mouth, and accessed pores as small as 0.4 µm. This suggests bacterial accessibility to different pore sizes is regulated by nutritional conditions. A combination of X-ray micro-CT scanning, gas adsorption and mercury intrusion porosimetry was used to characterize the range of pore sizes of soil aggregates. In case of the studied contaminated soil, the bioaccessible porosity were determined as 25% , 27% and 29% (assuming 4, 1, 0.4 µm respectively as accessibility criteria), and about 2.7% of aggregate volume was attributed to 0.006-0.4 µm pores. The 2% aggregate volume at an assumed saturation of 10% could

  16. Seismic Imaging of Mantle Plumes

    Science.gov (United States)

    Nataf, Henri-Claude

    The mantle plume hypothesis was proposed thirty years ago by Jason Morgan to explain hotspot volcanoes such as Hawaii. A thermal diapir (or plume) rises from the thermal boundary layer at the base of the mantle and produces a chain of volcanoes as a plate moves on top of it. The idea is very attractive, but direct evidence for actual plumes is weak, and many questions remain unanswered. With the great improvement of seismic imagery in the past ten years, new prospects have arisen. Mantle plumes are expected to be rather narrow, and their detection by seismic techniques requires specific developments as well as dedicated field experiments. Regional travel-time tomography has provided good evidence for plumes in the upper mantle beneath a few hotspots (Yellowstone, Massif Central, Iceland). Beneath Hawaii and Iceland, the plume can be detected in the transition zone because it deflects the seismic discontinuities at 410 and 660 km depths. In the lower mantle, plumes are very difficult to detect, so specific methods have been worked out for this purpose. There are hints of a plume beneath the weak Bowie hotspot, as well as intriguing observations for Hawaii. Beneath Iceland, high-resolution tomography has just revealed a wide and meandering plume-like structure extending from the core-mantle boundary up to the surface. Among the many phenomena that seem to take place in the lowermost mantle (or D''), there are also signs there of the presence of plumes. In this article I review the main results obtained so far from these studies and discuss their implications for plume dynamics. Seismic imaging of mantle plumes is still in its infancy but should soon become a turbulent teenager.

  17. Investigation of Balcony Plume Entrainment

    OpenAIRE

    Liu, F.; Nielsen, Peter V.; Heiselberg, Per; Brohus, Henrik; Li, B. Z.

    2009-01-01

    An investigation on the scenarios of the spill plume and its equation was presented in this paper. The study includes two aspects, i.e., the small-scale experiment and the numerical simulation. Two balcony spill plume models are assessed by comparing with the FDS (Fire Dynamic Simulation) and small scale model experiment results. Besides validating the spill model by experiments, the effect of different fire location on balcony plume is also discussed.The results show that the balcony equatio...

  18. Persistent organochlorine residues in human breast milk from Hanoi and Hochiminh City, Vietnam contamination, accumulation kinetics and risk assessment for infants

    International Nuclear Information System (INIS)

    Minh, Nguyen Hung; Someya, Masayuki; Minh, Tu Binh; Kunisue, Tatsuya; Iwata, Hisato; Watanabe, Mafumi; Tanabe, Shinsuke; Viet, Pham Hung; Tuyen, Bui Cach

    2004-01-01

    Despite the ban on persistent organochlorines (OCs) in most of the developed nations, their usage continued until recently in many Asian developing countries including Vietnam, for agricultural purposes and vector-borne disease eradication programs. In this study, we collected human breast milk samples from the two big cities in Vietnam: Hanoi (n=42) and Hochiminh (n=44) and determined the concentrations of persistent OCs such as PCBs, DDT and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), chlordane compounds (CHLs) and tris-4-chlorophenyl-methane (TCPMe). The contamination pattern of OCs was in the order of DDTs > PCBs > HCHs > CHLs∼HCB∼TCPMe. Compilation of available data indicated that DDT residue levels in human breast milk from Vietnam were among the highest values reported for Asian developing countries as well as developed nations. This result suggests recent usage of DDTs in both north and south Vietnam. Interestingly, in both cities, the p,p'-DDT portion was higher in multiparas than those in primiparas. Considering the fact that the interval between the first and the second child of a mother in Vietnam is usually short, this result probably indicates continuous intake of DDTs in the population. Analysis of infant exposure to DDTs via breast milk suggested that the daily intake rates for number of individuals are close to or above the threshold for adverse effects which may raise concern on children health. - It is suggested that daily intake rates of persistent organochlorines in mothers in Vietnam may result in health risk for nursing children

  19. Comparison of long-term stability of containment systems for residues and wastes contaminated with naturally occurring radionuclides at an arid site and two humid sites

    International Nuclear Information System (INIS)

    Winters, M.; Merry-Libby, P.; Hinchman, R.

    1985-01-01

    The long-term stability of near-surface containment systems designed for the management of radioactive wastes and residues contaminated with naturally occurring radionuclides are compared at the three different sites. The containment designs are: (1) a diked 8.9-m high mound, including a 3.2-m layered cap at a site (humid) near Lewiston, New York, (2) a 6.8-m-high mound, including a similar 3.2-m cap at a site (humid) near Oak Ridge, Tennessee, and (3) 4.8-m deep trenches with 3.0-m backfilled caps at a site (arid) near Hanford, Washington. Geological, hydrological, and biological factors affecting the long-term (1000-year) integrity of the containment systems at each site are examined, including: erosion, flooding, drought, wildfire, slope and cover failure, plant root penetration, burrowing animals, other soil-forming processes, and land-use changes. For the containment designs evaluated, releases of radon-222 at the arid site are predicted to be several orders of magnitude higher than at the two humid sites - upon initial burial and at 1000 years (after severe erosion). Transfer of wastes containing naturally occurring radionuclides from a humid to an arid environment offers little or no advantage relative to long-term stability of the containment system and has a definite disadvantage in terms of gaseous radioactive releases. 26 references, 3 figures, 4 tables

  20. The planet beyond the plume hypothesis

    Science.gov (United States)

    Smith, Alan D.; Lewis, Charles

    1999-12-01

    Acceptance of the theory of plate tectonics was accompanied by the rise of the mantle plume/hotspot concept which has come to dominate geodynamics from its use both as an explanation for the origin of intraplate volcanism and as a reference frame for plate motions. However, even with a large degree of flexibility permitted in plume composition, temperature, size, and depth of origin, adoption of any limited number of hotspots means the plume model cannot account for all occurrences of the type of volcanism it was devised to explain. While scientific protocol would normally demand that an alternative explanation be sought, there have been few challenges to "plume theory" on account of a series of intricate controls set up by the plume model which makes plumes seem to be an essential feature of the Earth. The hotspot frame acts not only as a reference but also controls plate tectonics. Accommodating plumes relegates mantle convection to a weak, sluggish effect such that basal drag appears as a minor, resisting force, with plates having to move themselves by boundary forces and continents having to be rifted by plumes. Correspondingly, the geochemical evolution of the mantle is controlled by the requirement to isolate subducted crust into plume sources which limits potential buffers on the composition of the MORB-source to plume- or lower mantle material. Crustal growth and Precambrian tectonics are controlled by interpretations of greenstone belts as oceanic plateaus generated by plumes. Challenges to any aspect of the plume model are thus liable to be dismissed unless a counter explanation is offered across the geodynamic spectrum influenced by "plume theory". Nonetheless, an alternative synthesis can be made based on longstanding petrological evidence for derivation of intraplate volcanism from volatile-bearing sources (wetspots) in conjunction with concepts dismissed for being incompatible or superfluous to "plume theory". In the alternative Earth, the sources for

  1. The Green Propellant Infusion Mission Thruster Performance Testing for Plume Diagnostics

    Science.gov (United States)

    Deans, Matthew C.; Reed, Brian D.; Arrington, Lynn A.; Williams, George J.; Kojima, Jun J.; Kinzbach, McKenzie I.; McLean, Christopher H.

    2014-01-01

    The Green Propellant Infusion Mission (GPIM) is sponsored by NASA's Space Technology Mission Directorate (STMD) Technology Demonstration Mission (TDM) office. The goal of GPIM is to advance the technology readiness level of a green propulsion system, specifically, one using the monopropellant, AF-M315E, by demonstrating ground handling, spacecraft processing, and on-orbit operations. One of the risks identified for GPIM is potential contamination of sensitive spacecraft surfaces from the effluents in the plumes of AF-M315E thrusters. NASA Glenn Research Center (GRC) is conducting activities to characterize the effects of AF-M315E plume impingement and deposition. GRC has established individual plume models of the 22-N and 1-N thrusters that will be used on the GPIM spacecraft. The model simulations will be correlated with plume measurement data from Laboratory and Engineering Model 22-N, AF-M315E thrusters. The thrusters are currently being tested in a small rocket, altitude facility at NASA GRC. A suite of diagnostics, including Raman spectroscopy, Rayleigh spectroscopy, and Schlieren imaging are being used to acquire plume measurements of AF-M315E thrusters. Plume data will include temperature, velocity, relative density, and species concentration. The plume measurement data will be compared to the corresponding simulations of the plume model. The GRC effort will establish a data set of AF-M315E plume measurements and a plume model that can be used for future AF-M315E applications.

  2. Plume Characterization of a Laboratory Model 22 N GPIM Thruster via High-Frequency Raman Spectroscopy

    Science.gov (United States)

    Williams, George J.; Kojima, Jun J.; Arrington, Lynn A.; Deans, Matthew C.; Reed, Brian D.; Kinzbach, McKenzie I.; McLean, Christopher H.

    2015-01-01

    The Green Propellant Infusion Mission (GPIM) will demonstrate the capability of a green propulsion system, specifically, one using the monopropellant, AF-M315E. One of the risks identified for GPIM is potential contamination of sensitive areas of the spacecraft from the effluents in the plumes of AF-M315E thrusters. Plume characterization of a laboratory-model 22 N thruster via optical diagnostics was conducted at NASA GRC in a space-simulated environment. A high-frequency pulsed laser was coupled with an electron-multiplied ICCD camera to perform Raman spectroscopy in the near-field, low-pressure plume. The Raman data yielded plume constituents and temperatures over a range of thruster chamber pressures and as a function of thruster (catalyst) operating time. Schlieren images of the near-field plume enabled calculation of plume velocities and revealed general plume structure of the otherwise invisible plume. The measured velocities are compared to those predicted by a two-dimensional, kinetic model. Trends in data and numerical results are presented from catalyst mid-life to end-of-life. The results of this investigation were coupled with the Raman and Schlieren data to provide an anchor for plume impingement analysis presented in a companion paper. The results of both analyses will be used to improve understanding of the nature of AF-M315E plumes and their impacts to GPIM and other future missions.

  3. Quantifying Contaminant Mass for the Feasibility Study of the DuPont Chambers Works FUSRAP Site - 13510

    Energy Technology Data Exchange (ETDEWEB)

    Young, Carl; Rahman, Mahmudur; Johnson, Ann; Owe, Stephan [Cabrera Services Inc., 1106 N. Charles St., Ste. 300, Baltimore, MD 21201 (United States)

    2013-07-01

    The U.S. Army Corps of Engineers (USACE) - Philadelphia District is conducting an environmental restoration at the DuPont Chambers Works in Deepwater, New Jersey under the Formerly Utilized Sites Remedial Action Program (FUSRAP). Discrete locations are contaminated with natural uranium, thorium-230 and radium-226. The USACE is proposing a preferred remedial alternative consisting of excavation and offsite disposal to address soil contamination followed by monitored natural attenuation to address residual groundwater contamination. Methods were developed to quantify the error associated with contaminant volume estimates and use mass balance calculations of the uranium plume to estimate the removal efficiency of the proposed alternative. During the remedial investigation, the USACE collected approximately 500 soil samples at various depths. As the first step of contaminant mass estimation, soil analytical data was segmented into several depth intervals. Second, using contouring software, analytical data for each depth interval was contoured to determine lateral extent of contamination. Six different contouring algorithms were used to generate alternative interpretations of the lateral extent of the soil contamination. Finally, geographical information system software was used to produce a three dimensional model in order to present both lateral and vertical extent of the soil contamination and to estimate the volume of impacted soil for each depth interval. The average soil volume from all six contouring methods was used to determine the estimated volume of impacted soil. This method also allowed an estimate of a standard deviation of the waste volume estimate. It was determined that the margin of error for the method was plus or minus 17% of the waste volume, which is within the acceptable construction contingency for cost estimation. USACE collected approximately 190 groundwater samples from 40 monitor wells. It is expected that excavation and disposal of

  4. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    The design of a displacement ventilation system involves determination of the flow rate in the thermal plumes. The flow rate in the plumes and the vertical temperature gradient influence each other, and they are influenced by many factors. This paper shows some descriptions of these effects....

  5. Plume rise from multiple sources

    International Nuclear Information System (INIS)

    Briggs, G.A.

    1975-01-01

    A simple enhancement factor for plume rise from multiple sources is proposed and tested against plume-rise observations. For bent-over buoyant plumes, this results in the recommendation that multiple-source rise be calculated as [(N + S)/(1 + S)]/sup 1/3/ times the single-source rise, Δh 1 , where N is the number of sources and S = 6 (total width of source configuration/N/sup 1/3/ Δh 1 )/sup 3/2/. For calm conditions a crude but simple method is suggested for predicting the height of plume merger and subsequent behavior which is based on the geometry and velocity variations of a single buoyant plume. Finally, it is suggested that large clusters of buoyant sources might occasionally give rise to concentrated vortices either within the source configuration or just downwind of it

  6. Plume rise predictions

    International Nuclear Information System (INIS)

    Briggs, G.A.

    1976-01-01

    Anyone involved with diffusion calculations becomes well aware of the strong dependence of maximum ground concentrations on the effective stack height, h/sub e/. For most conditions chi/sub max/ is approximately proportional to h/sub e/ -2 , as has been recognized at least since 1936 (Bosanquet and Pearson). Making allowance for the gradual decrease in the ratio of vertical to lateral diffusion at increasing heights, the exponent is slightly larger, say chi/sub max/ approximately h/sub e/ - 2 . 3 . In inversion breakup fumigation, the exponent is somewhat smaller; very crudely, chi/sub max/ approximately h/sub e/ -1 . 5 . In any case, for an elevated emission the dependence of chi/sub max/ on h/sub e/ is substantial. It is postulated that a really clever ignorant theoretician can disguise his ignorance with dimensionless constants. For most sources the effective stack height is considerably larger than the actual source height, h/sub s/. For instance, for power plants with no downwash problems, h/sub e/ is more than twice h/sub s/ whenever the wind is less than 10 m/sec, which is most of the time. This is unfortunate for anyone who has to predict ground concentrations, for he is likely to have to calculate the plume rise, Δh. Especially when using h/sub e/ = h/sub s/ + Δh instead of h/sub s/ may reduce chi/sub max/ by a factor of anywhere from 4 to infinity. Factors to be considered in making plume rise predictions are discussed

  7. Tracking stormwater discharge plumes and water quality of the Tijuana River with multispectral aerial imagery

    Science.gov (United States)

    Svejkovsky, Jan; Nezlin, Nikolay P.; Mustain, Neomi M.; Kum, Jamie B.

    2010-04-01

    Spatial-temporal characteristics and environmental factors regulating the behavior of stormwater runoff from the Tijuana River in southern California were analyzed utilizing very high resolution aerial imagery, and time-coincident environmental and bacterial sampling data. Thirty nine multispectral aerial images with 2.1-m spatial resolution were collected after major rainstorms during 2003-2008. Utilizing differences in color reflectance characteristics, the ocean surface was classified into non-plume waters and three components of the runoff plume reflecting differences in age and suspended sediment concentrations. Tijuana River discharge rate was the primary factor regulating the size of the freshest plume component and its shorelong extensions to the north and south. Wave direction was found to affect the shorelong distribution of the shoreline-connected fresh plume components much more strongly than wind direction. Wave-driven sediment resuspension also significantly contributed to the size of the oldest plume component. Surf zone bacterial samples collected near the time of each image acquisition were used to evaluate the contamination characteristics of each plume component. The bacterial contamination of the freshest plume waters was very high (100% of surf zone samples exceeded California standards), but the oldest plume areas were heterogeneous, including both polluted and clean waters. The aerial imagery archive allowed study of river runoff characteristics on a plume component level, not previously done with coarser satellite images. Our findings suggest that high resolution imaging can quickly identify the spatial extents of the most polluted runoff but cannot be relied upon to always identify the entire polluted area. Our results also indicate that wave-driven transport is important in distributing the most contaminated plume areas along the shoreline.

  8. Small rocket exhaust plume data

    Science.gov (United States)

    Chirivella, J. E.; Moynihan, P. I.; Simon, W.

    1972-01-01

    During recent cryodeposit tests with an 0.18-N thruster, the mass flux in the plume back field was measured for the first time for nitrogen, carbon dioxide, and a mixture of nitrogen, hydrogen, and ammonia at various inlet pressures. This mixture simulated gases that would be generated by a hydrazine plenum attitude propulsion system. The measurements furnish a base upon which to build a mathematical model of plume back flow that will be used in predicting the mass distribution in the boundary region of other plumes. The results are analyzed and compared with existing analytical predictions.

  9. Rise of a cold plume

    International Nuclear Information System (INIS)

    Kakuta, Michio

    1977-06-01

    The rise of smoke from the stacks of two research reactors in normal operation was measured by photogrametric method. The temperature of effluent gas is less than 20 0 C higher than that of the ambient air (heat emission of the order 10 4 cal s -1 ), and the efflux velocity divided by the wind speed is between 0.5 and 2.8 in all 16 smoke runs. The field data obtained within downwind distance of 150m are compared with those by plume rise formulas presently available. Considering the shape of bending-over plume, the Briggs' formula for 'jet' gives a reasonable explanation of the observed plume rise. (auth.)

  10. Site characterization and petroleum hydrocarbon plume mapping

    Energy Technology Data Exchange (ETDEWEB)

    Ravishankar, K. [Harding Lawson Associates, Houston, TX (United States)

    1996-12-31

    This paper presents a case study of site characterization and hydrocarbon contamination plume mapping/delineation in a gas processing plant in southern Mexico. The paper describes innovative and cost-effective use of passive (non-intrusive) and active (intrusive) techniques, including the use of compound-specific analytical methods for site characterization. The techniques used, on a demonstrative basis, include geophysical, geochemical, and borehole drilling. Geochemical techniques used to delineate the horizontal extent of hydrocarbon contamination at the site include soil gas surveys. The borehole drilling technique used to assess the vertical extent of contamination and confirm geophysical and geochemical data combines conventional hollow-stem auguring with direct push-probe using Geoprobe. Compound-specific analytical methods, such as hydrocarbon fingerprinting and a modified method for gasoline range organics, demonstrate the inherent merit and need for such analyses to properly characterize a site, while revealing the limitations of noncompound-specific total petroleum hydrocarbon analysis. The results indicate that the techniques used in tandem can properly delineate the nature and extent of contamination at a site; often supplement or complement data, while reducing the risk of errors and omissions during the assessment phase; and provide data constructively to focus site-specific remediation efforts. 7 figs.

  11. Cotton contamination

    CSIR Research Space (South Africa)

    Van der Sluijs, MHJ

    2018-05-01

    Full Text Available This review focusses on physical forms of contaminant including the presence, prevention and/or removal of foreign bodies, stickiness and seed-coat fragments rather than the type and quantity of chemical residues that might be present in cotton...

  12. Plume rise measurements at Turbigo

    Energy Technology Data Exchange (ETDEWEB)

    Anfossi, D

    1982-01-01

    This paper presents analyses of plume measurements obtained during that campaign by the ENEL ground-based Lidar. The five stacks of Turbigo Power Plant have different heights and emission parameters and their plumes usually combine, so a model for multiple sources was used to predict the plume rises. These predictions are compared with the observations. Measurements of sigma/sub v/ and sigma/sub z/ over the first 1000 m are compared with the curves derived from other observations in the Po Valley, using the no-lift balloon technique over the same range of downwind distance. Skewness and kurtosis distributions are shown, both along the vertical and the horizontal directions. In order to show the plume structure in more detail, we present two examples of Lidar-derived cross sections and the corresponding vertically and horizontally integrated concentration profiles.

  13. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter

    Axisymmeric circular buoyant jets are treated both theoretically and experimentally. From a literature study the author concludes that the state of experimental knowledge is less satisfactory. Further three different measuring methods have been established to investigate the thermal plumes from...

  14. Novel plume deflection concept testing

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed effort will explore the feasibility and effectiveness of utilizing an electrically driven thermal shield for use as part of rocket plume deflectors. To...

  15. Smoke plumes: Emissions and effects

    Science.gov (United States)

    Susan O' Neill; Shawn Urbanski; Scott Goodrick; Sim Larkin

    2017-01-01

    Smoke can manifest itself as a towering plume rising against the clear blue sky-or as a vast swath of thick haze, with fingers that settle into valleys overnight. It comes in many forms and colors, from fluffy and white to thick and black. Smoke plumes can rise high into the atmosphere and travel great distances across oceans and continents. Or smoke can remain close...

  16. Volcanic eruption plumes on Io

    International Nuclear Information System (INIS)

    Strom, R.G.; Terrile, R.J.; Masursky, H.; Hansen, C.

    1979-01-01

    The detection of an umbrella-shaped plume extending about 280 km above the bright limb of Io was one of the most important discoveries made during the Voyager 1 encounter with the jovian system. This discovery proves that Io is volcanically active at present, and the number and magnitude of these eruptions indicate that Io is the most volcanically active body so far discovered in the Solar System. Preliminary analyses of these eruptive plumes are presented. (U.K.)

  17. Long-term bioremediation of a subsurface plume in silty soil

    International Nuclear Information System (INIS)

    Mose, D.G.; Mushrush, G.W.

    2000-01-01

    In northern Virginia, a loss from a tank farm has produced two plumes, containing about 200,000 gal of diesel fuel, jet-A fuel, and gasoline. Evidence suggests that the longest part of the contamination plume moved to its present length of 2,500 ft in less than 5 years. Since natural biodegradation would require about 2,500 years to reduce the hydrocarbon contamination to the remediation endpoints, other methods have been considered. Excavation of the plumes would take an estimated 5 years. However, the tank farm is surrounded by commercial buildings and expensive homes, and many of these buildings would have to be removed to reach the plumes. Enhanced natural bioremediation would require about 200 years at a start-up cost of about $1 million dollars and recurring costs of approximately $500,000/year. Infiltration galleries and enhanced subsurface permeability could reduce the remediation time to as little as 20 years

  18. Redox potential distribution of an organic-rich contaminated site obtained by the inversion of self-potential data

    Science.gov (United States)

    Abbas, M.; Jardani, A.; Soueid Ahmed, A.; Revil, A.; Brigaud, L.; Bégassat, Ph.; Dupont, J. P.

    2017-11-01

    Mapping the redox potential of shallow aquifers impacted by hydrocarbon contaminant plumes is important for the characterization and remediation of such contaminated sites. The redox potential of groundwater is indicative of the biodegradation of hydrocarbons and is important in delineating the shapes of contaminant plumes. The self-potential method was used to reconstruct the redox potential of groundwater associated with an organic-rich contaminant plume in northern France. The self-potential technique is a passive technique consisting in recording the electrical potential distribution at the surface of the Earth. A self-potential map is essentially the sum of two contributions, one associated with groundwater flow referred to as the electrokinetic component, and one associated with redox potential anomalies referred to as the electroredox component (thermoelectric and diffusion potentials are generally negligible). A groundwater flow model was first used to remove the electrokinetic component from the observed self-potential data. Then, a residual self-potential map was obtained. The source current density generating the residual self-potential signals is assumed to be associated with the position of the water table, an interface characterized by a change in both the electrical conductivity and the redox potential. The source current density was obtained through an inverse problem by minimizing a cost function including a data misfit contribution and a regularizer. This inversion algorithm allows the determination of the vertical and horizontal components of the source current density taking into account the electrical conductivity distribution of the saturated and non-saturated zones obtained independently by electrical resistivity tomography. The redox potential distribution was finally determined from the inverted residual source current density. A redox map was successfully built and the estimated redox potential values correlated well with in

  19. Characterization of the main Iberian Peninsula and French Atlantic turbid plumes using MODIS satellite data

    OpenAIRE

    Fernandez Novoa, Diego

    2018-01-01

    A river plume can be defined as a water mass with different properties than surrounding ocean water, in terms of salinity, temperature, composition and color, due to the influence of a river discharge. This is because river inputs provide fresh water, nutrients, sediments, organic and inorganic material and/or contaminants, among others, into the ocean, modifying the physical, chemical and biological conditions of the coastal areas under influence. Therefore, plumes play a key role in the aff...

  20. Overview of NASA GRCs Green Propellant Infusion Mission Thruster Testing and Plume Diagnostics

    Science.gov (United States)

    Deans, Matthew C.; Reed, Brian D.; Yim, John T.; Arrington, Lynn A.; Williams, George J.; Kojima, Jun J.; McLean, Christopher H.

    2014-01-01

    The Green Propellant Infusion Mission (GPIM) is sponsored by NASA's Space Technology Mission Directorate (STMD) Technology Demonstration Mission (TDM) office. The goal of GPIM is to advance the technology readiness level of a green propulsion system, specifically, one using the monopropellant, AF-M315E, by demonstrating ground handling, spacecraft processing, and on-orbit operations. One of the risks identified for GPIM is potential contamination of sensitive spacecraft surfaces from the effluents in the plumes of AF-M315E thrusters. NASA Glenn Research Center (GRC) is conducting activities to characterize the effects of AF-M315E plume impingement and deposition. GRC has established individual plume models of the 22-N and 1-N thrusters that will be used on the GPIM spacecraft. The models describe the pressure, temperature, density, Mach number, and species concentration of the AF-M315E thruster exhaust plumes. The models are being used to assess the impingement effects of the AF-M315E thrusters on the GPIM spacecraft. The model simulations will be correlated with plume measurement data from Laboratory and Engineering Model 22-N, AF-M315E thrusters. The thrusters will be tested in a small rocket, altitude facility at NASA GRC. The GRC thruster testing will be conducted at duty cycles representatives of the planned GPIM maneuvers. A suite of laser-based diagnostics, including Raman spectroscopy, Rayleigh spectroscopy, Schlieren imaging, and physical probes will be used to acquire plume measurements of AFM315E thrusters. Plume data will include temperature, velocity, relative density, and species concentration. The plume measurement data will be compared to the corresponding simulations of the plume model. The GRC effort will establish a data set of AF-M315E plume measurements and a plume model that can be used for future AF-M315E applications.

  1. Lidar sounding of volcanic plumes

    Science.gov (United States)

    Fiorani, Luca; Aiuppa, Alessandro; Angelini, Federico; Borelli, Rodolfo; Del Franco, Mario; Murra, Daniele; Pistilli, Marco; Puiu, Adriana; Santoro, Simone

    2013-10-01

    Accurate knowledge of gas composition in volcanic plumes has high scientific and societal value. On the one hand, it gives information on the geophysical processes taking place inside volcanos; on the other hand, it provides alert on possible eruptions. For this reasons, it has been suggested to monitor volcanic plumes by lidar. In particular, one of the aims of the FP7 ERC project BRIDGE is the measurement of CO2 concentration in volcanic gases by differential absorption lidar. This is a very challenging task due to the harsh environment, the narrowness and weakness of the CO2 absorption lines and the difficulty to procure a suitable laser source. This paper, after a review on remote sensing of volcanic plumes, reports on the current progress of the lidar system.

  2. Hot rocket plume experiment - Survey and conceptual design. [of rhenium-iridium bipropellants

    Science.gov (United States)

    Millard, Jerry M.; Luan, Taylor W.; Dowdy, Mack W.

    1992-01-01

    Attention is given to a space-borne engine plume experiment study to fly an experiment which will both verify and quantify the reduced contamination from advanced rhenium-iridium earth-storable bipropellant rockets (hot rockets) and provide a correlation between high-fidelity, in-space measurements and theoretical plume and surface contamination models. The experiment conceptual design is based on survey results from plume and contamination technologists throughout the U.S. With respect to shuttle use, cursory investigations validate Hitchhiker availability and adaptability, adequate remote manipulator system (RMS) articulation and dynamic capability, acceptable RMS attachment capability, adequate power and telemetry capability, and adequate flight altitude and attitude/orbital capability.

  3. Mobile Bay turbidity plume study

    Science.gov (United States)

    Crozier, G. F.

    1976-01-01

    Laboratory and field transmissometer studies on the effect of suspended particulate material upon the appearance of water are reported. Quantitative correlations were developed between remotely sensed image density, optical sea truth data, and actual sediment load. Evaluation of satellite image sea truth data for an offshore plume projects contours of transmissivity for two different tidal phases. Data clearly demonstrate the speed of change and movement of the optical plume for water patterns associated with the mouth of Mobile bay in which relatively clear Gulf of Mexico water enters the bay on the eastern side. Data show that wind stress in excess of 15 knots has a marked impact in producing suspended sediment loads.

  4. Lithosphere erosion atop mantle plumes

    Science.gov (United States)

    Agrusta, R.; Arcay, D.; Tommasi, A.

    2012-12-01

    Mantle plumes are traditionally proposed to play an important role in lithosphere erosion. Seismic images beneath Hawaii and Cape Verde show a lithosphere-asthenosphere-boundary (LAB) up to 50 km shallower than the surroundings. However, numerical models show that unless the plate is stationary the thermo-mechanical erosion of the lithosphere does not exceed 30 km. We use 2D petrological-thermo-mechanical numerical models based on a finite-difference method on a staggered grid and marker in cell method to study the role of partial melting on the plume-lithosphere interaction. A homogeneous peridotite composition with a Newtonian temperature- and pressure-dependent viscosity is used to simulate both the plate and the convective mantle. A constant velocity, ranging from 5 to 12.5 cm/yr, is imposed at the top of the plate. Plumes are created by imposing a thermal anomaly of 150 to 350 K on a 50 km wide domain at the base of the model (700 km depth); the plate right above the thermal anomaly is 40 Myr old. Partial melting is modeled using batch-melting solidus and liquidus in anhydrous conditions. We model the progressive depletion of peridotite and its effect on partial melting by assuming that the melting degree only strictly increases through time. Melt is accumulated until a porosity threshold is reached and the melt in excess is then extracted. The rheology of the partially molten peridotite is determined using viscous constitutive relationship based on a contiguity model, which enables to take into account the effects of grain-scale melt distribution. Above a threshold of 1%, melt is instantaneously extracted. The density varies as a function of partial melting degree and extraction. Besides, we analyze the kinematics of the plume as it impacts a moving plate, the dynamics of time-dependent small-scale convection (SSC) instabilities developing in the low-viscosity layer formed by spreading of hot plume material at the lithosphere base, and the resulting thermal

  5. Rediscovery of an old article reporting that the area around the epicenter in Hiroshima was heavily contaminated with residual radiation, indicating that exposure doses of A-bomb survivors were largely underestimated.

    Science.gov (United States)

    Sutou, Shizuyo

    2017-09-01

    The A-bomb blast released a huge amount of energy: thermal radiation (35%), blast energy (50%), and nuclear radiation (15%). Of the 15%, 5% was initial radiation released within 30 s and 10% was residual radiation, the majority of which was fallout. Exposure doses of hibakusha (A-bomb survivors) were estimated solely on the basis of the initial radiation. The effects of the residual radiation on hibakusha have been considered controversial; some groups assert that the residual radiation was negligible, but others refute that assertion. I recently discovered a six-decade-old article written in Japanese by a medical doctor, Gensaku Obo, from Hiroshima City. This article clearly indicates that the area around the epicenter in Hiroshima was heavily contaminated with residual radiation. It reports that non-hibakusha who entered Hiroshima soon after the blast suffered from severe acute radiation sickness, including burns, external injuries, fever, diarrhea, skin bleeding, sore throat and loss of hair-as if they were real hibakusha. This means that (i) some of those who entered Hiroshima in the early days after the blast could be regarded as indirect hibakusha; (ii) 'in-the-city-control' people in the Life Span Study (LSS) must have been irradiated more or less from residual radiation and could not function properly as the negative control; (iii) exposure doses of hibakusha were largely underestimated; and (iv) cancer risk in the LSS was largely overestimated. Obo's article is very important to understand the health effects of A-bombs so that the essence of it is translated from Japanese to English with the permission of the publisher. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  6. Rediscovery of an old article reporting that the area around the epicenter in Hiroshima was heavily contaminated with residual radiation, indicating that exposure doses of A-bomb survivors were largely underestimated

    International Nuclear Information System (INIS)

    Sutou, Shizuyo

    2017-01-01

    The A-bomb blast released a huge amount of energy: thermal radiation (35%), blast energy (50%), and nuclear radiation (15%). Of the 15%, 5% was initial radiation released within 30 s and 10% was residual radiation, the majority of which was fallout. Exposure doses of hibakusha (A-bomb survivors) were estimated solely on the basis of the initial radiation. The effects of the residual radiation on hibakusha have been considered controversial; some groups assert that the residual radiation was negligible, but others refute that assertion. I recently discovered a six-decade-old article written in Japanese by a medical doctor, Gensaku Obo, from Hiroshima City. This article clearly indicates that the area around the epicenter in Hiroshima was heavily contaminated with residual radiation. It reports that non-hibakusha who entered Hiroshima soon after the blast suffered from severe acute radiation sickness, including burns, external injuries, fever, diarrhea, skin bleeding, sore throat and loss of hair—as if they were real hibakusha. This means that (i) some of those who entered Hiroshima in the early days after the blast could be regarded as indirect hibakusha; (ii) ‘in-the-city-control’ people in the Life Span Study (LSS) must have been irradiated more or less from residual radiation and could not function properly as the negative control; (iii) exposure doses of hibakusha were largely underestimated; and (iv) cancer risk in the LSS was largely overestimated. Obo's article is very important to understand the health effects of A-bombs so that the essence of it is translated from Japanese to English with the permission of the publisher.

  7. Multi-residue analysis of legacy POPs and emerging organic contaminants in Singapore's coastal waters using gas chromatography-triple quadrupole tandem mass spectrometry.

    Science.gov (United States)

    Zhang, Hui; Bayen, Stéphane; Kelly, Barry C

    2015-08-01

    A gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) based method was developed for determination of 86 hydrophobic organic compounds in seawater. Solid-phase extraction (SPE) was employed for sequestration of target analytes in the dissolved phase. Ultrasound assisted extraction (UAE) and florisil chromatography were utilized for determination of concentrations in suspended sediments (particulate phase). The target compounds included multi-class hydrophobic contaminants with a wide range of physical-chemical properties. This list includes several polycyclic and nitro-aromatic musks, brominated and chlorinated flame retardants, methyl triclosan, chlorobenzenes, organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). Spiked MilliQ water and seawater samples were used to evaluate the method performance. Analyte recoveries were generally good, with the exception of some of the more volatile target analytes (chlorobenzenes and bromobenzenes). The method is very sensitive, with method detection limits typically in the low parts per quadrillion (ppq) range. Analysis of 51 field-collected seawater samples (dissolved and particulate-bound phases) from four distinct coastal sites around Singapore showed trace detection of several polychlorinated biphenyl congeners and other legacy POPs, as well as several current-use emerging organic contaminants (EOCs). Polycyclic and nitro-aromatic musks, bromobenzenes, dechlorane plus isomers (syn-DP, anti-DP) and methyl triclosan were frequently detected at appreciable levels (2-20,000pgL(-1)). The observed concentrations of the monitored contaminants in Singapore's marine environment were generally comparable to previously reported levels in other coastal marine systems. To our knowledge, these are the first measurements of these emerging contaminants of concern in Singapore or Southeast Asia. The developed method may prove beneficial for future environmental monitoring of hydrophobic organic contaminants

  8. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, P.; Nielsen, Peter Vilhelm

    The main objective of ventilation is to provide good air quality for the occupants. For this purpose the necessary ventilating air change rate must be determined. Within displacement ventilation the estimation is closely related to the air flow rate in the thermal plumes when an air quality based...

  9. Ship exhaust gas plume cooling

    NARCIS (Netherlands)

    Schleijpen, H.M.A.; Neele, P.P.

    2004-01-01

    The exhaust gas plume is an important and sometimes dominating contributor to the infrared signature of ships. Suppression of the infrared ship signatures has been studied by TNO for the Royal Netherlands Navy over considerable time. This study deals with the suppression effects, which can be

  10. Characterization of redox conditions in pollution plumes

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Bjerg, Poul Løgstrup; Banwart, Steven A.

    2000-01-01

    Evalution of redox conditions in groundwater pollution plumes is often a prerequisite for understanding the behviour of the pollutants in the plume and for selecting remediation approaches. Measuring of redox conditions in pollution plumes is, however, a fairly recent issue and yet relative few...

  11. Chesapeake Bay plume dynamics from LANDSAT

    Science.gov (United States)

    Munday, J. C., Jr.; Fedosh, M. S.

    1981-01-01

    LANDSAT images with enhancement and density slicing show that the Chesapeake Bay plume usually frequents the Virginia coast south of the Bay mouth. Southwestern (compared to northern) winds spread the plume easterly over a large area. Ebb tide images (compared to flood tide images) show a more dispersed plume. Flooding waters produce high turbidity levels over the shallow northern portion of the Bay mouth.

  12. Plume residence and toxic material accumulation

    International Nuclear Information System (INIS)

    Spigarelli, S.A.; Holpuch, R.

    1975-01-01

    Increased growth rates and 137 Cs concentrations in plume resident trout are thought to be the result of increased metabolism, food consumption, and activity caused by exposure to increased water temperature and flow in thermal discharges. These exposure conditions could contribute to increased accumulation of biologically active, toxic substances by primary forage and predator fish species in the Great Lakes. Uptake and retention of various toxic substances by predators depend on concentrations in forage species (trophic transfer), ambient water, and point source effluents (direct uptake). Contaminants of immediate concern in Great Lakes systems (e.g., chlorinated hydrocarbons) accumulate in adipose tissue, and body concentrations have been correlated with total lipid content in fish. In addition to direct toxic effects on fish, many lipophilic contaminants are known to cause severe human health problems when ingested at concentrations commonly found in Lake Michigan salmonids. Although power plants may or may not be the direct source of a toxic substance, the thermal discharge environment may contribute to the accumulation of toxic substances in fish and the transfer of these materials to man

  13. Residues of dioxins (PCDD/Fs) and PCBs in eggs, fat and livers of laying hens following consumption of contaminated feed

    NARCIS (Netherlands)

    Traag, W.A.; Kan, C.A.; Weg, van der G.; Onstenk, C.G.M.; Hoogenboom, L.A.P.

    2006-01-01

    Laying hens were fed with feed from the Belgian dioxin incident diluted ten-fold with non-contaminated feed, resulting in concentrations of 61 ng TEQ kg(-1) PCDD/Fs, 23 ng TEQ kg(-1) non-ortho PCBs, 116 ng TEQ kg(-1) mono-ortho PCBs and 3.2 mg kg(-1) of the seven indicator PCBs. Following exposure

  14. Integrated project: Microbiological and physiological studies on the presence of residual concentrations in mineral-oil-contaminated soils after rehabilitation. Final report. Pt. 2; Mikrobiologische und physiologische Untersuchungen zur Frage der Restkonzentration bei der Sanierung mineraloelkontaminierter Boeden. Abschlussbericht. T. 2

    Energy Technology Data Exchange (ETDEWEB)

    Miethe, D.; Riis, V.; Stimming, M.

    1996-01-04

    It has been known for a long time that microorganisms are able to utilise mineral oils. Today various methods are practised which exploit autochthonous microorganisms` ability to utilise mineral oils. The main problem of microbial decomposition of hydrocarbons is that mineral oil residues remain. The aim of the present research project was therefore to determine the limits of the metabolisability of the substrate and find out why residues remain. Mineral oils and residual fractions differ markedly in their decomposability. Intermediate distillates are easily decomposed to a degree of 95-97% by well-adapted consorts. For high-boiling mineral oils (bp>400 C) the degree of decomposition is approx. 60%. Extracts from contaminated sites range from 40 to 60% in their degree of decomposability. The incomplete microbial decomposition of mineral oils is mainly due to their structure. There remain chemically and thermally extremely, inert hydrocarbons (mainly aliphatic and aromatic fused-ring systems) which are either hardly metabolisable or not at all. An important factor in soils or at other contaminated sites is that some of the substrate is not available because it is bound to the matrix thus increasing the proportion of residue. The next task after examining and presenting the causes of incomplete decomposition is to minimise residual mineral oil concentrations remaining after microbial decomposition. Here the use of special surfactants or of auxiliary substrates could point a way. Project applications to this end have already been submitted to the Federal Ministry for Education and Research. (orig.) [Deutsch] Dass Mikroorganismen in der Lage sind, Mineraloele zu verwerten, ist seit langem bekannt. Verfahren, die das Potential autochthoner Mikroorganismen zur Verwertung von Mineraloelen nutzen sind Praxis. Hauptproblem beim mikrobiellen Abbau der Kohlenwasserstoffe ist das Verbleiben von Mineraloelresten. Das Ziel des Forschungsvorhabens war die Ermittlung der Grenzen

  15. Chemical amendment and phytostabilization of an industrial residue contaminated with Zn and Cd Correção química e fitoestabilização de um resíduo industrial contaminado com Zn e Cd

    Directory of Open Access Journals (Sweden)

    Fabiana Soares dos Santos

    2007-10-01

    Full Text Available Phytostabilisation of a contaminated soil with heavy metals is considered a very appropriate technology to reduce erosion and dispersion of contaminants. A greenhouse study was conducted to evaluate the effects of both chemical amendments (calcium silicate and brewery sludge, and phytoremediation using the grass Brachiaria decumbens, on an industrial residue contaminated with Zn and Cd (industrial residue. Industrial residue samples placed into 30 L containers were amended with 20% brewery sludge, calcium silicate (2%, 3%, and 20% of brewery sludge + calcium silicate (2.5%, 4%, and were compared to the control treatment (non-amended residue. After pH stabilization, B. decumbens plants were grown on all treatments in order to evaluate the ability of the species to tolerate high Zn and Cd concentrations from the residue. Samples were collected twice, at planting and harvesting, for pH determination and simple extractions with water, sodium nitrate, acetic acid and DTPA. Differences in Zn and Cd concentrations in extracts allowed to estimate the concentrations of these elements in the most likely chemical forms they are found in the residue. Alkaline and organic industrial amendments reduced Zn and Cd percentages, both in the soluble and exchangeable fractions, as well as caused the predominance of Zn and Cd in the most stable chemical fractions, such as complexed and precipitated compounds. B. decumbens was tolerant to Zn and Cd from the industrial residue after addition of the amendments.A fitoestabilização de solos contaminados com metais pesados é considerada uma boa alternativa para reduzir a erosão e dispersão de contaminantes no ambiente. Foi conduzido um experimento em casa-de-vegetação com o objetivo de avaliar a contenção química (silicato de cálcio e lodo do biodigestor de uma cervejaria e a fitorremediação pela Brachiaria decumbens, de um resíduo industrial contaminado com Zn e Cd, utilizando vasos de 30 L. Os tratamentos

  16. The effects of Pantoea sp. strain Y4-4 on alfalfa in the remediation of heavy-metal-contaminated soil, and auxiliary impacts of plant residues on the remediation of saline-alkali soils.

    Science.gov (United States)

    Li, Shuhuan; Wang, Jie; Gao, Nanxiong; Liu, Lizhu; Chen, Yahua

    2017-04-01

    The plant-growth-promoting rhizobacterium (PGPR) Y4-4 was isolated from plant rhizosphere soil and identified as Pantoea sp. by 16S rRNA sequence analysis. The effects of strain Y4-4 on alfalfa grown in heavy-metals-contaminated soil was investigated using a pot experiment. In a Cu-rich environment, the shoot dry mass and total dry mass of plants inoculated with strain Y4-4 increased by 22.6% and 21%, and Cu accumulation increased by 15%. In a Pb-Zn-rich environment, the shoot dry mass and total dry mass of plants inoculated with strain Y4-4 increased by 23.4% and 22%, and Zn accumulation increased by 30.3%. In addition, the salt tolerance and biomass of wheat seedlings could be improved by applying strain Y4-4 mixed with plant residue as a result of the Cu-rich plant residues providing copper nutrition to wheat. This study offers an efficient PGPR with strong salt tolerance and a safe strategy for the post-treatment of plant residue.

  17. Turbulent forces within river plumes affect spread

    Science.gov (United States)

    Bhattacharya, Atreyee

    2012-08-01

    When rivers drain into oceans through narrow mouths, hydraulic forces squeeze the river water into buoyant plumes that are clearly visible in satellite images. Worldwide, river plumes not only disperse freshwater, sediments, and nutrients but also spread pollutants and organisms from estuaries into the open ocean. In the United States, the Columbia River—the largest river by volume draining into the Pacific Ocean from North America—generates a plume at its mouth that transports juvenile salmon and other fish into the ocean. Clearly, the behavior and spread of river plumes, such as the Columbia River plume, affect the nation's fishing industry as well as the global economy.

  18. Liquid Booster Module (LBM) plume flowfield model

    Science.gov (United States)

    Smith, S. D.

    1981-01-01

    A complete definition of the LBM plume is important for many Shuttle design criteria. The exhaust plume shape has a significant effect on the vehicle base pressure. The LBM definition is also important to the Shuttle base heating, aerodynamics and the influence of the exhaust plume on the launch stand and environment. For these reasons a knowledge of the LBM plume characteristics is necessary. A definition of the sea level LBM plume as well as at several points along the Shuttle trajectory to LBM, burnout is presented.

  19. Cone penetrometer tests and HydroPunch sampling: A screening technique for plume definition

    International Nuclear Information System (INIS)

    Smolley, M.; Kappmeyer, J.C.

    1991-01-01

    Cone penetrometer tests and HydroPunch sampling were used to define the extent of volatile organic compounds in ground water. The investigation indicated that the combination of the these techniques is effective for obtaining ground water samples for preliminary plume definition. HydroPunch samples can be collected in unconsolidated sediments and the analytical results obtained from these samples are comparable to those obtained from adjacent monitoring wells. This sampling method is a rapid and cost-effective screening technique for characterizing the extent of contaminant plumes in soft sediment environments. Use of this screening technique allowed monitoring wells to be located at the plume boundary, thereby reducing the number of wells installed and the overall cost of the plume definition program

  20. The decision-making process in dealing with populations living in areas contaminated by the uranium mining residues in Eastern Germany

    International Nuclear Information System (INIS)

    Kraus, W.; Ettenhuber, E.

    1998-01-01

    The radiological intervention situation created by uranium mining and milling residues is part of a more general problem: mining and other industrial residues with exposure to enhanced natural radiation. That part of the decision-making that should follow the principles of the radiological protection system is far from being a pre-established process. Problems are discussed that are connected with the justification and optimization of remediation measures, the establishing and meaning of action levels, as well as legal and institutional problems. They are the basis of considering the societal aspects of decision-making. The impact of public concerns on the decisions and their relation to the historic and social heritage and economic situation on the one hand, and experiences with different attempts to influence public attitudes towards radiological risks and decisions to be made on the other hand are dealt with. (author)

  1. Teaching the Mantle Plumes Debate

    Science.gov (United States)

    Foulger, G. R.

    2010-12-01

    There is an ongoing debate regarding whether or not mantle plumes exist. This debate has highlighted a number of issues regarding how Earth science is currently practised, and how this feeds into approaches toward teaching students. The plume model is an hypothesis, not a proven fact. And yet many researchers assume a priori that plumes exist. This assumption feeds into teaching. That the plume model is unproven, and that many practising researchers are skeptical, may be at best only mentioned in passing to students, with most teachers assuming that plumes are proven to exist. There is typically little emphasis, in particular in undergraduate teaching, that the origin of melting anomalies is currently uncertain and that scientists do not know all the answers. Little encouragement is given to students to become involved in the debate and to consider the pros and cons for themselves. Typically teachers take the approach that “an answer” (or even “the answer”) must be taught to students. Such a pedagogic approach misses an excellent opportunity to allow students to participate in an important ongoing debate in Earth sciences. It also misses the opportunity to illustrate to students several critical aspects regarding correct application of the scientific method. The scientific method involves attempting to disprove hypotheses, not to prove them. A priori assumptions should be kept uppermost in mind and reconsidered at all stages. Multiple working hypotheses should be entertained. The predictions of a hypothesis should be tested, and unpredicted observations taken as weakening the original hypothesis. Hypotheses should not be endlessly adapted to fit unexpected observations. The difficulty with pedagogic treatment of the mantle plumes debate highlights a general uncertainty about how to teach issues in Earth science that are not yet resolved with certainty. It also represents a missed opportunity to let students experience how scientific theories evolve, warts

  2. Stabilization of in-tank residual wastes and external-tank soil contamination for the tank focus area, Hanford Tank Initiative: Applications to the AX tank farm

    International Nuclear Information System (INIS)

    Becker, D.L.

    1997-01-01

    This report investigates five technical areas for stabilization of decommissioned waste tanks and contaminated soils at the Hanford Site AX Farm. The investigations are part of a preliminary evacuation of end-state options for closure of the AX Tanks. The five technical areas investigated are: (1) emplacement of cementations grouts and/or other materials; (2) injection of chemicals into contaminated soils surrounding tanks (soil mixing); (3) emplacement of grout barriers under and around the tanks; (4) the explicit recognition that natural attenuation processes do occur; and (5) combined geochemical and hydrological modeling. Research topics are identified in support of key areas of technical uncertainty, in each of the five areas. Detailed cost-benefit analyses of the technologies are not provided. This investigation was conducted by Sandia National Laboratories, Albuquerque, New Mexico, during FY 1997 by tank Focus Area (EM-50) funding

  3. Residues of chlortetracycline, doxycycline and sulfadiazine-trimethoprim in intestinal content and feces of pigs due to cross-contamination of feed.

    Science.gov (United States)

    Peeters, Laura E J; Daeseleire, Els; Devreese, Mathias; Rasschaert, Geertrui; Smet, Annemieke; Dewulf, Jeroen; Heyndrickx, Marc; Imberechts, Hein; Haesebrouck, Freddy; Butaye, Patrick; Croubels, Siska

    2016-09-20

    Cross-contamination of feed with low concentrations of antimicrobials can occur at production, transport and/or farm level. Concerns are rising about possible effects of this contaminated feed on resistance selection in the intestinal microbiota. Therefore, an experiment with pigs was set up, in which intestinal and fecal concentrations of chlortetracycline (CTC), doxycycline (DOX) and sulfadiazine-trimethoprim (SDZ-TRIM) were determined after administration of feed containing a 3 % carry-over level of these antimicrobials. The poor oral bioavailability of tetracyclines resulted in rather high concentrations in cecal and colonic content and feces at steady-state conditions. A mean concentration of 10 mg/kg CTC and 4 mg/kg DOX in the feces was reached, which is higher than concentrations that were shown to cause resistance selection. On the other hand, lower mean levels of SDZ (0.7 mg/kg) and TRIM (< limit of detection of 0.016 mg/kg) were found in the feces, corresponding with the high oral bioavailability of SDZ and TRIM in pigs. The relation between the oral bioavailability and intestinal concentrations of the tested antimicrobials, may be of help in assessing the risks of cross-contaminated feed. However, future research is needed to confirm our results and to evaluate the effects of these detected concentrations on resistance selection in the intestinal microbiota of pigs.

  4. Geochemical evolution of highly alkaline and saline tank waste plumes during seepage through vadose zone sediments

    International Nuclear Information System (INIS)

    Wan, Jiamin; Tokunaga, Tetsu K.; Larsen, Joern T.; Serne, R. JEFFREY

    2004-01-01

    Leakage of highly saline and alkaline radioactive waste from storage tanks into underlying sediments is a serious environmental problem at the Hanford Site in Washington State. This study focuses on geochemical evolution of tank waste plumes resulting from interactions between the waste solution and sediment. A synthetic tank waste solution was infused into unsaturated Hanford sediment columns (0.2, 0.6, and 2 m) maintained at 70C to simulate the field contamination process. Spatially and temporally resolved geochemical profiles of the waste plume were obtained. Thorough OH neutralization (from an initial pH 14 down to 6.3) was observed. Three broad zones of pore solutions were identified to categorize the dominant geochemical reactions: the silicate dissolution zone (pH > 10), pH-neutralized zone (pH 10 to 6.5), and displaced native sediment pore water (pH 6.5 to 8). Elevated concentrations of Si, Fe, and K in plume fluids and their depleted concentrations in plume sediments reflected dissolution of primary minerals within the silicate dissolution zone. The very high Na concentrations in the waste solution resulted in rapid and complete cation exchange, reflected in high concentrations of Ca and Mg at the plume front. The plume-sediment profiles also showed deposition of hydrated solids and carbonates. Fair correspondence was obtained between these results and analyses of field borehole samples from a waste plume at the Hanford Site. Results of this study provide a well-defined framework for understanding waste plumes in the more complex field setting and for understanding geochemical factors controlling transport of contaminant species carried in waste solutions that leaked from single-shell storage tanks in the past

  5. Mantle plumes on Venus revisited

    Science.gov (United States)

    Kiefer, Walter S.

    1992-01-01

    The Equatorial Highlands of Venus consist of a series of quasicircular regions of high topography, rising up to about 5 km above the mean planetary radius. These highlands are strongly correlated with positive geoid anomalies, with a peak amplitude of 120 m at Atla Regio. Shield volcanism is observed at Beta, Eistla, Bell, and Atla Regiones and in the Hathor Mons-Innini Mons-Ushas Mons region of the southern hemisphere. Volcanos have also been mapped in Phoebe Regio and flood volcanism is observed in Ovda and Thetis Regiones. Extensional tectonism is also observed in Ovda and Thetis Regiones. Extensional tectonism is also observed in many of these regions. It is now widely accepted that at least Beta, Atla, Eistla, and Bell Regiones are the surface expressions of hot, rising mantel plumes. Upwelling plumes are consistent with both the volcanism and the extensional tectonism observed in these regions. The geoid anomalies and topography of these four regions show considerable variation. Peak geoid anomalies exceed 90 m at Beta and Atla, but are only 40 m at Eistla and 24 m at Bell. Similarly, the peak topography is greater at Beta and Atla than at Eistla and Bell. Such a range of values is not surprising because terrestrial hotspot swells also have a side range of geoid anomalies and topographic uplifts. Kiefer and Hager used cylindrical axisymmetric, steady-state convection calculations to show that mantle plumes can quantitatively account for both the amplitude and the shape of the long-wavelength geoid and topography at Beta and Atla. In these models, most of the topography of these highlands is due to uplift by the vertical normal stress associated with the rising plume. Additional topography may also be present due to crustal thickening by volcanism and crustal thinning by rifting. Smrekar and Phillips have also considered the geoid and topography of plumes on Venus, but they restricted themselves to considering only the geoid-topography ratio and did not

  6. Origin of VC-only plumes from naturally enhanced dechlorination in a peat-rich hydrogeologic setting

    Science.gov (United States)

    Filippini, Maria; Amorosi, Alessandro; Campo, Bruno; Herrero-Martìn, Sara; Nijenhuis, Ivonne; Parker, Beth L.; Gargini, Alessandro

    2016-09-01

    The occurrence of vinyl chloride (VC) is often a main concern at sites contaminated with chlorinated solvents due to its high degree of toxicity and carcinogenicity. VC occurrence in aquifers is most often related to the degradation of higher chlorinated ethenes or ethanes and it is generally detected in plumes along with parent contaminants. However, specific combination of stratigraphic, hydrogeologic and geochemical conditions can enhance the degradation of parents and lead to the formation of plumes almost entirely composed of VC (i.e. VC-only plumes). This paper investigates the causes of VC-only plumes in the aquifers below the city of Ferrara (northern Italy) by combining multiple lines of evidence. The City of Ferrara is located on an alluvial lowland, built by the River Po, and is made up of alternating unconsolidated sandy aquifer and silt-clay aquitard deposits of fluvial origin. This region has been strongly impacted by prior industrial activities, with the occurrence of chlorinated compounds at several sites. VC-only plumes with uncertain source location were found at two contaminated sites. The source zone of a third plume composed of chloroethenes from PCE to VC was investigated for high resolution depositional facies architecture and contaminant distribution (contaminant concentration and Compound Specific Isotope Analysis - CSIA). The investigation suggested that degradation of PCE and TCE takes place during contaminant migration through peat-rich (swamp) layers related to the Holocene transgression, which locally act as a ;reactor; for stimulating degradation with the accumulation of VC in the strongly reducing environment of the peat. Regional-scale stratigraphic architecture showed the ubiquitous occurrence of swamp layers at distinct stratigraphic levels in the investigated system and their apparent linkage to the in situ creation of the VC-only plumes.

  7. Use of filler limestone and construction and demolition residues for remediating soils contaminated with heavy metals: an assessment by means of plant uptake.

    Science.gov (United States)

    Banegas, Ascension; Martinez-Sanchez, Maria Jose; Agudo, Ines; Perez-Sirvent, Carmen

    2010-05-01

    A greenhouse trial was carried out to evaluate the assimilation of heavy metals by three types of horticultural plants (lettuce, broccoli and alfalfa), different parts of which are destined for human and animal consumption (leaves, roots, fruits). The plants were cultivated in four types of soil, one uncontaminated (T1), one soil collected in the surrounding area of Sierra Minera (T2), the third being remediated with residues coming from demolition and construction activities (T3) and the four remediated with filler limestone (T4). To determine the metal content, soil samples were first ground to a fine powder using an agate ball mill. Fresh vegetable samples were separated into root and aboveground biomass and then lyophilized. The DTPA-extractable content was also determined to calculate the bioavailable amount of metal. Finally, the translocation factor (TF) and bioconcentration factor (BCF) were calculated. Arsenic levels were obtained by using atomic fluorescence spectrometry with an automated continuous flow hydride generation (HG-AFS) spectrometer and Cd, Pb and Zn was determined by electrothermal atomization atomic absorption spectrometry (ETAAS) or flame atomic absorption spectrometry (FAAS). Samples of the leached water were also obtained and analyzed. According to our results, the retention of the studied elements varies with the type of plant and is strongly decreased by the incorporation of filler limestone and/or construction and demolition residues to the soils. This practice represents a suitable way to reduce the risk posed to the biota by the presence of high levels of heavy metal in soil.

  8. Distribuição e biodisponibilidade de crômio em solos contaminados por resíduos de couro Distribution and bioavailability of chromium in contaminated soils by tannery residues

    Directory of Open Access Journals (Sweden)

    Ademir dos Santos

    2009-01-01

    Full Text Available Samples of soil, water and sediment were collected and analyzed in order to evaluate chromium contamination due to deposition of tannery residues onto soils under different management regimes. The results showed that soils used for sugar cane cultivation were not adversely impacted. However, in the case of mango plantations, variable concentrations of chromium were measured in the soil profile, with 22.2% of values being higher than permitted legal limits, and 38.9% being at levels requiring remediation. Concentrations of bioavailable chromium were lower than the detection limit of the method (0.01 mg of chromium kg-1 of soil, indicating that all of the chromium present in the samples was either complexed or in an insoluble form. Chromium concentrations measured in samples of water and sediments were indicative of low mobility of the metal in soils. The main cause of differences found between soil samples obtained from different cultivations was the type of soil management.

  9. Application of Aspergillus niger-treated agrowaste residue and Glomus mosseae for improving growth and nutrition of Trifolium repens in a Cd-contaminated soil.

    Science.gov (United States)

    Medina, A; Vassilev, N; Barea, J M; Azcón, R

    2005-04-06

    The microbial transformation of sugar beet (SB) agrowaste with or without rock-phosphate (RP) has utility for the improvement of plant growth in a Cd (5 microg g-1) artificially contaminated soil, particularly when the soil is co-inoculated with arbuscular mycorrhizal (AM) fungus Glomus mosseae isolated from a Cd-polluted area. Under such Cd-polluted conditions, the limited growth, mineral nutrition, symbiotic developments (nodulation and AM-colonization) and soil enzymatic activities were stimulated using SB or SB+RP as soil amendments and G. mosseae as inoculant. G. mosseae enhanced plant establishment in a higher extent in amended soil; it is probably due to the interactive effect increasing the potential fertility of such compounds and its ability for decreasing Cd transfer from soil to plant. The amount of Cd transferred from soil solution to biomass of AM-colonized plants ranged from 0.09 microg Cd g-1 (in SB+RP-amended soil) to 0.6 microg Cd g-1 (in non-amended soil). Nodule formation was more sensitive to Cd than AM-colonization, and both symbioses were stimulated in amended soils. Not only AM-colonization but also amendments were critical for plant growth and nutrition in Cd-polluted soil. The high effectiveness of AM inoculum increasing nutrients and decreasing Cd in amended soil indicated the positive interaction of these treatments in increasing plant tolerance to Cd contamination.

  10. Significance of treated agrowaste residue and autochthonous inoculates (Arbuscular mycorrhizal fungi and Bacillus cereus) on bacterial community structure and phytoextraction to remediate soils contaminated with heavy metals.

    Science.gov (United States)

    Azcón, Rosario; Medina, Almudena; Roldán, Antonio; Biró, Borbála; Vivas, Astrid

    2009-04-01

    In this study, we analyzed the impact of treatments such as Aspergillus niger-treated sugar beet waste (SB), PO4(3-) fertilization and autochthonous inoculants [arbuscular mycorrhizal (AM) fungi and Bacillus cereus], on the bacterial community structure in a soils contaminated with heavy metals as well as, the effectiveness on plant growth (Trifolium repens). The inoculation with AM fungi in SB amended soil, increased plant growth similarly to PO4(3-) addition, and both treatments matched in P acquisition but bacterial biodiversity estimated by denaturing gradient gel electrophoresis of amplified 16S rDNA sequences, was more stimulated by the presence of the AM fungus than by PO4(3-) fertilization. The SB amendment plus AM inoculation increased the microbial diversity by 233% and also changed (by 215%) the structure of the bacterial community. The microbial inoculants and amendment used favoured plant growth and the phytoextraction process and concomitantly modified bacterial community in the rhizosphere; thus they can be used for remediation. Therefore, the understanding of such microbial ecological aspects is important for phytoremediation and the recovery of contaminated soils.

  11. The determination of pesticide residues and contaminants in fish and rice. Part of a coordinated programme on nuclear detection and analysis

    International Nuclear Information System (INIS)

    Lee, C.; Kim, Y.S.

    1975-03-01

    Neutron activation involving chemical procedures was used in order to present a reliable picture of the backgrounds of toxic elements such as Hg, As, Cd, Br, Cu and others in the biosphere. This report covers the analyses of reference kale samples, rice, fresh-water fish, marine fish, river water, fruits and farm products. Two results of Hg contents which were obtained by two independent methods indicated the difference in matrix effects depending on the type of samples, e.g., the standard reference kale of Bowen and fish showed the same effect while rice was different. Among fresh-water fish, snakeheads contained high Hg contents compared to other species. This could be attributed to their characteristics of feeding on fish. The analytical results of fish and waters of Han River show that the river is heavily contaminated with Hg and Cd of which sources are manifold and increase in number as the stream flows downward. Some species of marine fish which are expected to dwell on the sea beds or sea shores contained relatively high Hg and/or Cd contents compared to other species. Some interpretations of the analytical results were attempted with the object of pointing out the sources of the contamination, but this met some difficulties

  12. A retrospective assessment of gold mining in the Reedy Creek sub-catchment, northeast Victoria, Australia: residual mercury contamination 100 years later

    International Nuclear Information System (INIS)

    Churchill, R.C.; Meathrel, C.E.; Suter, P.J.

    2004-01-01

    The mining of gold can lead to toxic metals such as mercury (Hg) contaminating watercourses as by-products. The Reedy Creek sub-catchment, in northeast Victoria, Australia, was mined for gold in the 1850s. In 1998, samples were taken from six watercourses to measure any remaining toxic metal contamination in sediments and surface waters from two creeks with no previous gold mining (controls) and four that were mined. Although mean concentrations of Hg (measured using an ICP-OES) in sediments were below worldwide background levels, individual sites along Reedy Creek had slightly elevated Hg concentrations. In contrast, the Hg concentrations in the surface waters were above background levels. Temporal fluxes of very high Hg concentrations in the surface waters during periods of first flow and flood events revealed that Hg concentrations in the surface waters may, at certain times of the year, exceed all Australian and New Zealand Environment and Conservation Council (National Water Quality Management Strategy. Australian Water Quality Guidelines for Fresh and Marine Waters, ANZECC, 2000) guidelines for water use and the protection of the aquatic ecosystem

  13. 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...

  14. Ecogenomics of microbial communities in bioremediation of chlorinated contaminated sites

    NARCIS (Netherlands)

    Maphosa, F.; Lieten, S.; Dinkla, I.; Stams, A.J.M.; Fennel, D.E.

    2012-01-01

    Organohalide compounds such as chloroethenes, chloroethanes, and polychlorinated benzenes are among the most significant pollutants in the world. These compounds are often found in contamination plumes with other pollutants such as solvents, pesticides, and petroleum derivatives. Microbial

  15. The determination of pesticide residues and contaminants in vegetables by means of neutron activation analysis. Part of a coordinated programme on nuclear detection and analysis

    International Nuclear Information System (INIS)

    Mongkolphanta, S.

    1977-11-01

    Neutron activation techniques have been applied to study the existence of pesticide residues (As, Br, Hg) and pollutants (Cd, Co, Zn) in local vegetable and fruit samples, polished and unpolished glutinous and non-glutinous milled rice, and fish caught in polluted and unpolluted areas of the Gulf of Thailand. Since the baseline levels of these toxic elements in vegetables, fruits, rice and fish are not known as yet, the results cannot be regarded as conclusive. Furthermore, no significant difference was observed in the concentration of these elements in fish caught in polluted and unpolluted areas. The Gulf of Thailand does not therefore appear to be polluted at present. The substoichiometric isotope dilution technique was successfully applied to mercury determinations, and only to a limited extent to Cd due to shutdown of the TRR-1 reactor

  16. Predicting the distribution of contamination from a chlorinated hydrocarbon release

    Energy Technology Data Exchange (ETDEWEB)

    Lupo, M.J. [K.W. Brown Environmental Services, College Station, TX (United States); Moridis, G.J. [Lawrence Berkeley Laboratory, Berkeley, CA (United States)

    1995-03-01

    The T2VOC model with the T2CG1 conjugate gradient package was used to simulate the motion of a dense chlorinated hydrocarbon plume released from an industrial plant. The release involved thousands of kilograms of trichloroethylene (TCE) and other chemicals that were disposed of onsite over a period of nearly twenty years. After the disposal practice ceased, an elongated plume was discovered. Because much of the plume underlies a developed area, it was of interest to study the migration history of the plume to determine the distribution of the contamination.

  17. Trial of a novel plasma gas disinfection system (Radica) to reduce mattress residual bacterial contamination in the acute hospital setting: a preliminary study.

    Science.gov (United States)

    Shiely, F; Fallon, D; Casey, C; Kerins, D M; Eustace, J A

    2017-02-01

    In routine clinical practice, mattresses are manually cleaned using specialised cleaning and high-level disinfecting fluids. While effective against a wide range of organisms, the success of this approach is dependent on a thorough and complete application and is likely to be susceptible to human error and thus variable. The efficacy of available infection control measures to reduce such mattress contamination is unknown as it is not subject to quality control measures. There is a pressing need to identify more effective methods to prevent cross contamination within the medical environment, given the lack of available treatment strategies. The purpose of this study is to investigate the ability of a new technology, gaseous technology, to reduce colonization levels, compared to standard cleaning, and so attenuate superficial nosocomial infections. We conducted a prospective, single-centre, open-label, non-randomized trial with blinded outcome assessments, comparing the standard cleaning of hospital mattresses with a novel plasma based disinfection system Radica™, followed by a standard post-cleaning culturing protocol (five swabs/mattress). The median (interquartile range) maximal colony count per mattress for the 20 Radica versus 7 routinely cleaned mattresses was 1 (1-2.7) versus Too-Numerous-to-Count (TNTC) (32-TNTC), respectively, p = 0.002. Of the 20 Radica™ treated mattresses, 12 (60 %) had no positive culture result while all of the standard cleaned mattresses had at least two positive cultures. The plasma based Radica disinfection system reduces mattress bacterial colonization levels as compared to routine cleaning. This is a potentially important technology in the health care system to reduce surface colonisation and hence nosocomial infections.

  18. Particle Simulation of Pulsed Plasma Thruster Plumes

    National Research Council Canada - National Science Library

    Boyd, Ian

    2002-01-01

    .... Our modeling had made progress in al aspects of simulating these complex devices including Teflon ablation, plasma formation, electro-magnetic acceleration, plume expansion, and particulate transport...

  19. Are terrestrial plumes from motionless plates analogues to Martian plumes feeding the giant shield volcanoes?

    Science.gov (United States)

    Meyzen, Christine; Massironi, Matteo; Pozzobon, Riccardo; Dal Zilio, Luca

    2014-05-01

    The near "one-plate" planet evolution of Mars has led to the edification of long-lasting giant shied volcanoes. Unlike the Earth, Mars would have been a transient convecting planet, where plate tectonic would have possibly acted only during the first hundreds of million years of its history. On Earth, where plate tectonic is active, most of them are regenerated and recycled through convection. However, the Nubian and Antarctic plates could be considered as poorly mobile surfaces of various thicknesses that are acting as conductive lids on top of Earth's deeper convective system. In these environments, volcanoes do not show any linear age progression at least for the last 30 Ma, but constitute the sites of persistent, focused long-term magmatic activity, rather than a chain of volcanoes as observed in fast-moving plate plume environments. Here, the near stationary absolute plate motion probably exerts a primary control on volcanic processes, and more specifically, on the melting ones. The residual depleted mantle, that is left behind by the melting processes, cannot be swept away from the melting locus. Over time, the thickening of this near-stationary depleted layer progressively forces the termination of melting to higher depths, reducing the melt production rate. Such a process gradually leads both to decreasing efficient melt extraction and increasing mantle lithospheric-melt interactions. The accumulation of this refractory material also causes long-term fluctuations of the volcanic activity, in generating long periods of quiescence. The presence of this residual mantle keel induces over time a lateral flow deflection, which translates into a shift of future melting sites around it. This process gives rise to the horseshoe-like shape of some volcanic islands on slow-moving plates (e.g. Cape Verde, Crozet). Finally, the pronounced topographic swells/bulges observed in this environments may also be supported both by large scale mantle upwelling and their residual

  20. Plume spread and atmospheric stability

    Energy Technology Data Exchange (ETDEWEB)

    Weber, R O [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The horizontal spread of a plume in atmospheric dispersion can be described by the standard deviation of horizontal direction. The widely used Pasquill-Gifford classes of atmospheric stability have assigned typical values of the standard deviation of horizontal wind direction and of the lapse rate. A measured lapse rate can thus be used to estimate the standard deviation of wind direction. It is examined by means of a large dataset of fast wind measurements how good these estimates are. (author) 1 fig., 2 refs.

  1. Lidar measurements of plume statistics

    DEFF Research Database (Denmark)

    Ejsing Jørgensen, Hans; Mikkelsen, T.

    1993-01-01

    of measured crosswind concentration profiles, the following statistics were obtained: 1) Mean profile, 2) Root mean square profile, 3) Fluctuation intensities,and 4)Intermittency factors. Furthermore, some experimentally determined probability density functions (pdf's) of the fluctuations are presented. All...... the measured statistics are referred to a fixed and a 'moving' frame of reference, the latter being defined as a frame of reference from which the (low frequency) plume meander is removed. Finally, the measured statistics are compared with statistics on concentration fluctuations obtained with a simple puff...

  2. Integrated characterization of natural attenuation of a PCE plume after thermal remediation of the source zone - incl. dual isotope and microbial techniques

    DEFF Research Database (Denmark)

    Broholm, Mette Martina

    dechlorination 1-1.5 km downstream the source area, where the plume descends into more reduced groundwater. The objective of the new (2014) study is to evaluate how the source remediation has impacted the plume and in particular the natural attenuation within the plume. A large monitoring campaign including...... down-gradient which co-inside with the reduction in redox conditions. The findings document a significant increase in cDCE degradation without accumulation of VC. This reduces the risk posed by the contaminant plume to the drinking water resource. This project is unique in the integrated...... area, resulted in the release of dissolved organic matter and some geochemical changes. This has had an effect on redox conditions and biodegradation by reductive dechlorination particularly in the near source area. However, also in the further downstream area of the plume redox and contaminant levels...

  3. Characteristics of bubble plumes, bubble-plume bubbles and waves from wind-steepened wave breaking

    NARCIS (Netherlands)

    Leifer, I.; Caulliez, G.; Leeuw, G. de

    2007-01-01

    Observations of breaking waves, associated bubble plumes and bubble-plume size distributions were used to explore the coupled evolution of wave-breaking, wave properties and bubble-plume characteristics. Experiments were made in a large, freshwater, wind-wave channel with mechanical wind-steepened

  4. Simulation of plume rise: Study the effect of stably stratified turbulence layer on the rise of a buoyant plume from a continuous source by observing the plume centroid

    Science.gov (United States)

    Bhimireddy, Sudheer Reddy; Bhaganagar, Kiran

    2016-11-01

    Buoyant plumes are common in atmosphere when there exists a difference in temperature or density between the source and its ambience. In a stratified environment, plume rise happens until the buoyancy variation exists between the plume and ambience. In a calm no wind ambience, this plume rise is purely vertical and the entrainment happens because of the relative motion of the plume with ambience and also ambient turbulence. In this study, a plume centroid is defined as the plume mass center and is calculated from the kinematic equation which relates the rate of change of centroids position to the plume rise velocity. Parameters needed to describe the plume are considered as the plume radius, plumes vertical velocity and local buoyancy of the plume. The plume rise velocity is calculated by the mass, momentum and heat conservation equations in their differential form. Our study focuses on the entrainment velocity, as it depicts the extent of plume growth. This entrainment velocity is made up as sum of fractions of plume's relative velocity and ambient turbulence. From the results, we studied the effect of turbulence on the plume growth by observing the variation in the plume radius at different heights and the centroid height reached before loosing its buoyancy.

  5. Modelling the fate of the Tijuana River discharge plume

    Science.gov (United States)

    van Ormondt, M.; Terrill, E.; Hibler, L. F.; van Dongeren, A. R.

    2010-12-01

    After rainfall events, the Tijuana River discharges excess runoff into the ocean in a highly turbid plume. The runoff waters contain large suspended solids concentrations, as well as high levels of toxic contaminants, bacteria, and hepatitis and enteroviruses. Public health hazards posed by the effluent often result in beach closures for several kilometers northward along the U.S. shoreline. A Delft3D model has been set up to predict the fate of the Tijuana River plume. The model takes into account the effects of tides, wind, waves, salinity, and temperature stratification. Heat exchange with the atmosphere is also included. The model consists of a relatively coarse outer domain and a high-resolution surf zone domain that are coupled with Domain Decomposition. The offshore boundary conditions are obtained from the larger NCOM SoCal model (operated by the US Navy) that spans the entire Southern California Bight. A number of discharge events are investigated, in which model results are validated against a wide range of field measurements in the San Diego Bight. These include HF Radar surface currents, REMUS tracks, drifter deployments, satellite imagery, as well as current and temperature profile measurements at a number of locations. The model is able to reproduce the observed current and temperature patterns reasonably well. Under calm conditions, the model results suggest that the hydrodynamics in the San Diego Bight are largely governed by internal waves. During rainfall events, which are typically accompanied by strong winds and high waves, wind and wave driven currents become dominant. An analysis will be made of what conditions determine the trapping and mixing of the plume inside the surfzone and/or the propagation of the plume through the breakers and onto the coastal shelf. The model is now also running in operational mode. Three day forecasts are made every 24 hours. This study was funded by the Office of Naval Research.

  6. Innovative Strategy For Long Term Monitoring Of Metal And Radionuclide Plumes

    International Nuclear Information System (INIS)

    Eddy-Dilek, Carol; Millings, Margaret R.; Looney, Brian B.; Denham, Miles E.

    2014-01-01

    Many government and private industry sites that were once contaminated with radioactive and chemical wastes cannot be cleaned up enough to permit unrestricted human access. The sites will require long term management, in some cases indefinitely, leaving site owners with the challenge of protecting human health and environmental quality at these 'legacy' sites. Long-term monitoring of groundwater contamination is one of the largest projected costs in the life cycle of environmental management at the Savannah River Site, the larger DOE complex, and many large federal and private sites. There is a need to optimize the performance and manage the cost of long term surveillance and monitoring at their sites. Currently, SRNL is initiating a pilot field test using alternative protocols for long term monitoring of metals and radionuclides. A key component of the approach is that monitoring efforts are focused on measurement of low cost metrics related to hydrologic and chemical conditions that control contaminant migration. The strategy combines careful monitoring of hydrologic boundary conditions with measurement of master variables such as chemical surrogates along with a smaller number of standard well analyses. In plumes contaminated with metals, master variables control the chemistry of the groundwater system, and include redox variables (ORP, DO, chemicals), pH, specific conductivity, biological community (breakdown/decay products), and temperature. Significant changes in these variables will result in conditions whereby the plume may not be stable and therefore can be used to predict possible plume migration. Conversely, concentration measurements for all types of contaminants in groundwater are a lagging indicator plume movement - major changes contaminant concentrations indicate that contamination has migrated. An approach based on measurement of master variables and explicit monitoring of hydrologic boundary conditions combined with traditional metrics should lead

  7. Innovative Strategy For Long Term Monitoring Of Metal And Radionuclide Plumes

    Energy Technology Data Exchange (ETDEWEB)

    Eddy-Dilek, Carol; Millings, Margaret R.; Looney, Brian B.; Denham, Miles E.

    2014-01-08

    Many government and private industry sites that were once contaminated with radioactive and chemical wastes cannot be cleaned up enough to permit unrestricted human access. The sites will require long term management, in some cases indefinitely, leaving site owners with the challenge of protecting human health and environmental quality at these "legacy" sites. Long-term monitoring of groundwater contamination is one of the largest projected costs in the life cycle of environmental management at the Savannah River Site, the larger DOE complex, and many large federal and private sites. There is a need to optimize the performance and manage the cost of long term surveillance and monitoring at their sites. Currently, SRNL is initiating a pilot field test using alternative protocols for long term monitoring of metals and radionuclides. A key component of the approach is that monitoring efforts are focused on measurement of low cost metrics related to hydrologic and chemical conditions that control contaminant migration. The strategy combines careful monitoring of hydrologic boundary conditions with measurement of master variables such as chemical surrogates along with a smaller number of standard well analyses. In plumes contaminated with metals, master variables control the chemistry of the groundwater system, and include redox variables (ORP, DO, chemicals), pH, specific conductivity, biological community (breakdown/decay products), and temperature. Significant changes in these variables will result in conditions whereby the plume may not be stable and therefore can be used to predict possible plume migration. Conversely, concentration measurements for all types of contaminants in groundwater are a lagging indicator plume movement - major changes contaminant concentrations indicate that contamination has migrated. An approach based on measurement of master variables and explicit monitoring of hydrologic boundary conditions combined with traditional metrics should lead

  8. GKSS-workshop: contaminated sludges. Treatment and utilization fine graned residues; GKSS-Workshop: Kontaminierte Schlaemme. Behandlung und Nutzungsmoeglichkeiten feinkoerniger Reststoffe

    Energy Technology Data Exchange (ETDEWEB)

    Alvermann, G.; Luther, G.; Niemeyer, B. [eds.] [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Zentralabteilung Technikum

    2000-07-01

    New regulations, such as the materials recycling act, soil protection act and unsolved problems related to the treatment of contaminated sludges, the utilisation of the gained products demand the development of innovative techniques for industrial, dredged or drilling sludges. The workshop offered a platform for intensive discussions between representatives of industry, research institutions, associations, and authorities. The main aim of the workshop was the presentation of fundamental background of sludge processing and advanced technical solutions. The available proceedings contain 21 lectures held on the workshop with the following ranges of topics of the sludge treatment: legislation, R and D-funding, technological bases, decontamination processes, dewatering and drying processes, recycling and immobilization. (orig.) [German] Neue Gesetze wie das Kreislaufwirtschafts- oder das Bundes-Bodenschutzgesetz und anstehende Probleme bei der Beseitigung belasteter Schlaemme - zum Beispiel Industrie-, Bohr- und Baggergutschlaemme - erfordern die Entwicklung innovativer Techniken zu ihrer Aufbereitung, Reinigung bzw. Verwertung. Der Workshop bot ein Formung zur intensiven Diskussion zwischen Industrie, Forschung, Verbaenden und Behoerden. Ziel war es, unterschiedliche Methoden der Schlammbehandlung zu eroertern, Loesungswege aufzuzeigen und Moeglichkeiten fuer Kooperationen zu erarbeiten. Der vorliegende Band enthaelt Beitraege der Referenten, die sich auf folgende Themenbereiche der Schlammbehandlung konzentrieren: juristische Aspekte, Foerdermoeglichkeiten, Grundlagen, Aufbereitung von Schlaemmen, Entwaesserung und Trocknung von Schlaemmen, Verwertung und Immobilisierung. (orig.)

  9. Characterization of redox conditions in groundwater contaminant plumes

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Bjerg, Poul Løgstrup; Banwarth, Steven A.

    2000-01-01

    tools, such as MPN counts, PLFA biomarkers and redox bioassays. This paper reviews the principles behind the different approaches, summarizes methods used and evaluates the approaches based on the experience from the reported applications. C 2000 Elsevier Science B.V. All rights reserved....

  10. Spatial and temporal migration of a landfill leachate plume in alluvium

    Science.gov (United States)

    Masoner, Jason R.; Cozzarelli, Isabelle M.

    2015-01-01

    Leachate from unlined or leaky landfills can create groundwater contaminant plumes that last decades to centuries. Understanding the dynamics of leachate movement in space and time is essential for monitoring, planning and management, and assessment of risk to groundwater and surface-water resources. Over a 23.4-year period (1986–2010), the spatial extent of the Norman Landfill leachate plume increased at a rate of 7800 m2/year and expanded by 878 %, from an area of 20,800 m2 in 1986 to 203,400 m2 in 2010. A linear plume velocity of 40.2 m/year was calculated that compared favorably to a groundwater-seepage velocity of 55.2 m/year. Plume-scale hydraulic conductivity values representative of actual hydrogeological conditions in the alluvium ranged from 7.0 × 10−5 to 7.5 × 10−4 m/s, with a median of 2.0 × 10−4 m/s. Analyses of field-measured and calculated plume-scale hydraulic conductivity distributions indicate that the upper percentiles of field-measured values should be considered to assess rates of plume-scale migration, spreading, and biodegradation. A pattern of increasing Cl− concentrations during dry periods and decreasing Cl− concentrations during wet periods was observed in groundwater beneath the landfill. The opposite occurred in groundwater downgradient from the landfill; that is, Cl− concentrations in groundwater downgradient from the landfill decreased during dry periods and increased during wet periods. This pattern of changing Cl−concentrations in response to wet and dry periods indicates that the landfill retains or absorbs leachate during dry periods and produces lower concentrated leachate downgradient. During wet periods, the landfill receives more recharge which dilutes leachate in the landfill but increases leachate migration from the landfill and produces a more concentrated contaminant plume. This approach of quantifying plume expansion, migration, and concentration during variable hydrologic

  11. Abundance of Dreissena polymorpha and Dreissena bugensis in a warmwater plume: effects of depth and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, J.S.; Bailey, R.C.; Knapton, R.W. [Simon Fraser University, Burnaby, BC (Canada). Department of Biological Sciences

    1996-08-01

    The abundance of mussel populations in areas affected by waste water discharges is examined. Measurements were made of the variation with depth in the abundance of zebra and of quagga mussels both inside and outside the area affected by the warm water plume from the Ontario Hydro Nanticoke coal-fired generating station on Lake Erie. The pattern of the residual variation relative to the warm water plume was then examined. The study allows a partial decoupling of depth and temperature effects. The results are discussed. 27 refs., 2 figs., 2 tabs.

  12. Dilution and volatilization of groundwater contaminant discharges in streams

    DEFF Research Database (Denmark)

    Aisopou, Angeliki; Bjerg, Poul Løgstrup; Sonne, Anne Thobo

    2015-01-01

    measurement. The solution was successfully applied to published field data obtained in a large and a small Danish stream and provided valuable information on the risk posed by the groundwater contaminant plumes. The results provided by the dilution and volatilization model are very different to those obtained......An analytical solution to describe dilution and volatilization of a continuous groundwater contaminant plume into streams is developed for risk assessment. The location of groundwater plume discharge into the stream (discharge through the side versus bottom of the stream) and different...

  13. Proceedings of plumes, plates and mineralisation symposium: an introduction

    CSIR Research Space (South Africa)

    Hatton, CJ

    1997-12-01

    Full Text Available of plume-theory. Mechanisms of magma formation are identified and plume positions and distances to their surface expression considered. Mantle plumes are considered as a heat and fluid source for the Witwatersrand gold deposits....

  14. Alternativas de utilização de resíduos sólidos alcalinos na disposição de resíduos contaminados: estudo de caso no estado do Rio de Janeiro, Brasil Alkaline residues alternatives for use in the landfill of a contaminated solid residues: case study from Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Wilma de Carvalho Pereira

    2008-06-01

    Full Text Available Este trabalho tem como objetivo o estudo dos elementos potencialmente contaminantes presentes nos rejeitos industriais que são dispostos no meio ambiente e, por processo de lixiviação, carreados para os corpos hídricos. Dois tipos de resíduos foram estudados. Um deles, proveniente da indústria de produção de aço (escória da aciaria, de características alcalina. Este rejeito é considerado relativamente estável pelos padrões vigentes devido às suas características (CdThe goal of this work is to study the potentially contaminating trace elements present in industrial waste that is discharged into the environment though lixiviation process to water resources. Two types of waste were studied. The first one, a refuse slag from steel industry, an alkaline residue. Even though this waste is considered relatively stable within the established standards set by current legislation due to its characteristics (Cd<0.5 mg/Kg, Pb<10 mg/Kg, Co<5 mg/Kg, Cu=61 mg/Kg, Ni<1.5 mg/Kg, Zn=75 mg/Kg, there is so far no feasible alternative for its total reutilization. The other one a residue from the electroplating industry (Class I: ABNT, 1987, closed down in 1998.

  15. Io with Loki Plume on Bright Limb

    Science.gov (United States)

    1990-01-01

    Voyager 1 image of Io showing active plume of Loki on limb. Heart-shaped feature southeast of Loki consists of fallout deposits from active plume Pele. The images that make up this mosaic were taken from an average distance of approximately 490,000 kilometers (340,000 miles).

  16. The Alberta smoke plume observation study

    Directory of Open Access Journals (Sweden)

    K. Anderson

    2018-02-01

    Full Text Available A field project was conducted to observe and measure smoke plumes from wildland fires in Alberta. This study used handheld inclinometer measurements and photos taken at lookout towers in the province. Observations of 222 plumes were collected from 21 lookout towers over a 6-year period from 2010 to 2015. Observers reported the equilibrium and maximum plume heights based on the plumes' final levelling heights and the maximum lofting heights, respectively. Observations were tabulated at the end of each year and matched to reported fires. Fire sizes at assessment times and forest fuel types were reported by the province. Fire weather conditions were obtained from the Canadian Wildland Fire Information System (CWFIS. Assessed fire sizes were adjusted to the appropriate size at plume observation time using elliptical fire-growth projections. Though a logical method to collect plume observations in principle, many unanticipated issues were uncovered as the project developed. Instrument limitations and environmental conditions presented challenges to the investigators, whereas human error and the subjectivity of observations affected data quality. Despite these problems, the data set showed that responses to fire behaviour conditions were consistent with the physical processes leading to plume rise. The Alberta smoke plume observation study data can be found on the Canadian Wildland Fire Information System datamart (Natural Resources Canada, 2018 at http://cwfis.cfs.nrcan.gc.ca/datamart.

  17. The Alberta smoke plume observation study

    Science.gov (United States)

    Anderson, Kerry; Pankratz, Al; Mooney, Curtis; Fleetham, Kelly

    2018-02-01

    A field project was conducted to observe and measure smoke plumes from wildland fires in Alberta. This study used handheld inclinometer measurements and photos taken at lookout towers in the province. Observations of 222 plumes were collected from 21 lookout towers over a 6-year period from 2010 to 2015. Observers reported the equilibrium and maximum plume heights based on the plumes' final levelling heights and the maximum lofting heights, respectively. Observations were tabulated at the end of each year and matched to reported fires. Fire sizes at assessment times and forest fuel types were reported by the province. Fire weather conditions were obtained from the Canadian Wildland Fire Information System (CWFIS). Assessed fire sizes were adjusted to the appropriate size at plume observation time using elliptical fire-growth projections. Though a logical method to collect plume observations in principle, many unanticipated issues were uncovered as the project developed. Instrument limitations and environmental conditions presented challenges to the investigators, whereas human error and the subjectivity of observations affected data quality. Despite these problems, the data set showed that responses to fire behaviour conditions were consistent with the physical processes leading to plume rise. The Alberta smoke plume observation study data can be found on the Canadian Wildland Fire Information System datamart (Natural Resources Canada, 2018) at http://cwfis.cfs.nrcan.gc.ca/datamart.

  18. Radionuclide inventories for the F- and H-area seepage basin groundwater plumes

    Energy Technology Data Exchange (ETDEWEB)

    Hiergesell, Robert A [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Kubilius, Walter P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-05-01

    Within the General Separations Areas (GSA) at the Savannah River Site (SRS), significant inventories of radionuclides exist within two major groundwater contamination plumes that are emanating from the F- and H-Area seepage basins. These radionuclides are moving slowly with groundwater migration, albeit more slowly due to interaction with the soil and aquifer matrix material. The purpose of this investigation is to quantify the activity of radionuclides associated with the pore water component of the groundwater plumes. The scope of this effort included evaluation of all groundwater sample analyses obtained from the wells that have been established by the Environmental Compliance & Area Completion Projects (EC&ACP) Department at SRS to monitor groundwater contamination emanating from the F- and H-Area Seepage Basins. Using this data, generalized groundwater plume maps for the radionuclides that occur in elevated concentrations (Am-241, Cm-243/244, Cs-137, I-129, Ni-63, Ra-226/228, Sr-90, Tc-99, U-233/234, U-235 and U-238) were generated and utilized to calculate both the volume of contaminated groundwater and the representative concentration of each radionuclide associated with different plume concentration zones.

  19. Dig-face monitoring during excavation of a radioactive plume at Mound Laboratory, Ohio

    International Nuclear Information System (INIS)

    Josten, N.E.; Gehrke, R.J.; Carpenter, M.V.

    1995-12-01

    A dig-face monitoring system consists of onsite hardware for collecting information on changing chemical, radiological, and physical conditions in the subsurface soil during the hazardous site excavation. A prototype dig-face system was take to Mount Laboratory for a first trial. Mound Area 7 was the site of historical disposals of 232 Th, 227 Ac, and assorted debris. The system was used to monitor a deep excavation aimed at removing 227 Ac-contaminated soils. Radiological, geophysical, and topographic sensors were used to scan across the excavation dig-face at four successive depths as soil was removed. A 3-D image of the contamination plumes was developed; the radiation sensor data indicated that only a small portion of the excavated soil volume was contaminated. The spatial information produced by the dig-face system was used to direct the excavation activities into the area containing the 227 Ac and to evaluate options for handling the separate 232 Th plume

  20. Measurements on cooling tower plumes. Pt. 3

    International Nuclear Information System (INIS)

    Fortak, H.

    1975-11-01

    In this paper an extended field experiment is described in which cooling tower plumes were investigated by means of three-dimensional in situ measurements. The goal of this program was to obtain input data for numerical models of cooling tower plumes. Data for testing or developing assumptions for sub-grid parametrizations were of special interest. Utilizing modern systems for high-resolution aerology and small aircraft, four measuring campaigns were conducted: two campaigns (1974) at the cooling towers of the RWE power station at Neurath and also two (1975) at the single cooling tower of the RWE power station at Meppen. Because of the broad spectrum of weather situations, it can be assumed that the results are representative with regard to the interrelationship between the structure of cooling tower plumes and the large-scale meteorological situation. A large number of flights with a powered glider ASK 16 (more than 100 flight hours) crossing the plumes on orthogonal tracks was performed. All flights showed that the plume could be identified up to large downwind distances by discontinuous jumps of temperature and vapour pressure. Therefore a definite geometry of the plume could always be defined. In all cross sections a vertical circulation could be observed. At the plumes boundaries, which could be defined by the mentioned jumps of temperature and vapour pressure, a maximum of downward vertical motion was observed in most cases. Entrainment along the boundary of a cross section seems to be very small, except at the lower part of the plume. There, the mass entrainment is maximum and is responsible for plume rise as well as for enlargement of the cross section. The visible part of the plume (cloud) was only a small fraction of the whole plume. The discontinuities of temperature and vapour pressure show that the plume fills the space below the visible plume down to the ground. However, all effects decrease rapidly towards the ground. It turned out that high

  1. Follow the plume: the habitability of Enceladus.

    Science.gov (United States)

    McKay, Christopher P; Anbar, Ariel D; Porco, Carolyn; Tsou, Peter

    2014-04-01

    The astrobiological exploration of other worlds in our Solar System is moving from initial exploration to more focused astrobiology missions. In this context, we present the case that the plume of Enceladus currently represents the best astrobiology target in the Solar System. Analysis of the plume by the Cassini mission indicates that the steady plume derives from a subsurface liquid water reservoir that contains organic carbon, biologically available nitrogen, redox energy sources, and inorganic salts. Furthermore, samples from the plume jetting out into space are accessible to a low-cost flyby mission. No other world has such well-studied indications of habitable conditions. Thus, the science goals that would motivate an Enceladus mission are more advanced than for any other Solar System body. The goals of such a mission must go beyond further geophysical characterization, extending to the search for biomolecular evidence of life in the organic-rich plume. This will require improved in situ investigations and a sample return.

  2. Galileo observations of volcanic plumes on Io

    Science.gov (United States)

    Geissler, P.E.; McMillan, M.T.

    2008-01-01

    Io's volcanic plumes erupt in a dazzling variety of sizes, shapes, colors and opacities. In general, the plumes fall into two classes, representing distinct source gas temperatures. Most of the Galileo imaging observations were of the smaller, more numerous Prometheus-type plumes that are produced when hot flows of silicate lava impinge on volatile surface ices of SO2. Few detections were made of the giant, Pele-type plumes that vent high temperature, sulfur-rich gases from the interior of Io; this was partly because of the insensitivity of Galileo's camera to ultraviolet wavelengths. Both gas and dust spout from plumes of each class. Favorably located gas plumes were detected during eclipse, when Io was in Jupiter's shadow. Dense dust columns were imaged in daylight above several Prometheus-type eruptions, reaching heights typically less than 100 km. Comparisons between eclipse observations, sunlit images, and the record of surface changes show that these optically thick dust columns are much smaller in stature than the corresponding gas plumes but are adequate to produce the observed surface deposits. Mie scattering calculations suggest that these conspicuous dust plumes are made up of coarse grained “ash” particles with radii on the order of 100 nm, and total masses on the order of 106 kg per plume. Long exposure images of Thor in sunlight show a faint outer envelope apparently populated by particles small enough to be carried along with the gas flow, perhaps formed by condensation of sulfurous “snowflakes” as suggested by the plasma instrumentation aboard Galileo as it flew through Thor's plume [Frank, L.A., Paterson, W.R., 2002. J. Geophys. Res. (Space Phys.) 107, doi:10.1029/2002JA009240. 31-1]. If so, the total mass of these fine, nearly invisible particles may be comparable to the mass of the gas, and could account for much of Io's rapid resurfacing.

  3. Delta Chromium-53/52 isotopic composition of native and contaminated groundwater, Mojave Desert, USA

    Science.gov (United States)

    Izbicki, John A.; Bullen, Thomas D.; Martin, Peter; Schroth, Brian

    2012-01-01

    Chromium(VI) concentrations in groundwater sampled from three contaminant plumes in aquifers in the Mojave Desert near Hinkley, Topock and El Mirage, California, USA, were as high as 2600, 5800 and 330 μg/L, respectively. δ53/52Cr compositions from more than 50 samples collected within these plumes ranged from near 0‰ to almost 4‰ near the plume margins. Assuming only reductive fractionation of Cr(VI) to Cr(III) within the plume, apparent fractionation factors for δ53/52Cr isotopes ranged from εapp = 0.3 to 0.4 within the Hinkley and Topock plumes, respectively, and only the El Mirage plume had a fractionation factor similar to the laboratory derived value of ε = 3.5. One possible explanation for the difference between field and laboratory fractionation factors at the Hinkley and Topock sites is localized reductive fractionation of Cr(VI) to Cr(III), with subsequent advective mixing of native and contaminated water near the plume margin. Chromium(VI) concentrations and δ53/52Cr isotopic compositions did not uniquely define the source of Cr near the plume margin, or the extent of reductive fractionation within the plume. However, Cr(VI) and δ53/52Cr data contribute to understanding of the interaction between reductive and mixing processes that occur within and near the margins of Cr contamination plumes. Reductive fractionation of Cr(VI) predominates in plumes having higher εapp, these plumes may be suitable for monitored natural attenuation. In contrast, advective mixing predominates in plumes having lower εapp, the highly dispersed margins of these plumes may be difficult to define and manage.

  4. Undisturbed dust as a metric of long-term indoor insecticide exposure: Residential DDT contamination from indoor residual spraying and its association with serum levels in the VHEMBE cohort.

    Science.gov (United States)

    Gaspar, Fraser W; Chevrier, Jonathan; Bornman, Riana; Crause, Madelein; Obida, Muvhulawa; Barr, Dana Boyd; Bradman, Asa; Bouwman, Henk; Eskenazi, Brenda

    2015-12-01

    Although approximately 123 million people may be exposed to high levels of insecticides through the use of indoor residual spraying (IRS) for malaria control, few studies exist on indoor insecticide contamination due to IRS and its relationship with human exposure. In the present study, we developed a sampling method to collect undisturbed dust from 50 homes in Limpopo, South Africa, a region where dichlorodiphenyltrichloroethane (DDT) has been used in IRS programs to prevent malaria for ~70years. We quantified DDT and its degradation products, dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyldichloroethane (DDD) in dust samples to determine dust loading levels and compared these levels to paired serum concentrations of p,p'-DDT and p,p'-DDE in women residents. p,p'-DDT and p,p'-DDE had the highest detection frequencies in both dust (58% and 34% detection, respectively) and serum samples (98% and 100% detection, respectively). Significantly higher detection frequencies for o,p'-DDT, p,p'-DDE, and p,p'-DDD were observed in dust samples collected in buildings that had been previously sprayed for malaria control. We also observed a significant, positive association between dust loading and serum concentrations of p,p'-DDT and p,p'-DDE (Spearman's rho=0.68 and 0.54, respectively). Despite the low detection frequency in dust, our results indicate that undisturbed dust may be a good metric to quantify long-term home exposure to DDT-related compounds and that contamination of the home environment may be an important determinant/source of DDT and DDE exposure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Residual stresses

    International Nuclear Information System (INIS)

    Sahotra, I.M.

    2006-01-01

    The principal effect of unloading a material strained into the plastic range is to create a permanent set (plastic deformation), which if restricted somehow, gives rise to a system of self-balancing within the same member or reaction balanced by other members of the structure., known as residual stresses. These stresses stay there as locked-in stresses, in the body or a part of it in the absence of any external loading. Residual stresses are induced during hot-rolling and welding differential cooling, cold-forming and extruding: cold straightening and spot heating, fabrication and forced fitting of components constraining the structure to a particular geometry. The areas which cool more quickly develop residual compressive stresses, while the slower cooling areas develop residual tensile stresses, and a self-balancing or reaction balanced system of residual stresses is formed. The phenomenon of residual stresses is the most challenging in its application in surface modification techniques determining endurance mechanism against fracture and fatigue failures. This paper discusses the mechanism of residual stresses, that how the residual stresses are fanned and what their behavior is under the action of external forces. Such as in the case of a circular bar under limit torque, rectangular beam under limt moment, reclaiming of shafts welds and peening etc. (author)

  6. Io's Active Eruption Plumes: Insights from HST

    Science.gov (United States)

    Jessup, K. L.; Spencer, J. R.

    2011-10-01

    Taking advantage of the available data, we recently [10] completed a detailed analysis of the spectral signature of Io's Pele-type Tvashtar plume as imaged by the HST Wide Field and Planetary Camera 2 (HST/WFPC2) via absorption during Jupiter transit and via reflected sunlight in 2007, as well as HST/WFPC2 observations of the 1997 eruption of Io's Prometheus-type Pillan plume (Fig. 1). These observations were obtained in the 0.24-0.42 μm range, where the plumes gas absorption and aerosol scattering properties are most conspicuous. By completing a detailed analysis of these observations, several key aspects of the reflectance and the absorption properties of the two plumes have been revealed. Additionally, by considering the analysis of the HST imaging data in light of previously published spectral analysis of Io's Prometheus and Pele-type plumes several trends in the plume properties have been determined, allowing us to define the relative significance of each plume on the rate of re-surfacing occurring on Io and providing the measurements needed to better assess the role the volcanoes play in the stability of Io's tenuous atmosphere.

  7. Simplified scheme or radioactive plume calculations

    International Nuclear Information System (INIS)

    Gibson, T.A.; Montan, D.N.

    1976-01-01

    A simplified mathematical scheme to estimate external whole-body γ radiation exposure rates from gaseous radioactive plumes was developed for the Rio Blanco Gas Field Nuclear Stimulation Experiment. The method enables one to calculate swiftly, in the field, downwind exposure rates knowing the meteorological conditions and γ radiation exposure rates measured by detectors positioned near the plume source. The method is straightforward and easy to use under field conditions without the help of mini-computers. It is applicable to a wide range of radioactive plume situations. It should be noted that the Rio Blanco experiment was detonated on May 17, 1973, and no seep or release of radioactive material occurred

  8. Contamination analysis unit

    International Nuclear Information System (INIS)

    Gregg, H.R.; Meltzer, M.P.

    1996-01-01

    The portable Contamination Analysis Unit (CAU) measures trace quantities of surface contamination in real time. The detector head of the portable contamination analysis unit has an opening with an O-ring seal, one or more vacuum valves and a small mass spectrometer. With the valve closed, the mass spectrometer is evacuated with one or more pumps. The O-ring seal is placed against a surface to be tested and the vacuum valve is opened. Data is collected from the mass spectrometer and a portable computer provides contamination analysis. The CAU can be used to decontaminate and decommission hazardous and radioactive surfaces by measuring residual hazardous surface contamination, such as tritium and trace organics. It provides surface contamination data for research and development applications as well as real-time process control feedback for industrial cleaning operations and can be used to determine the readiness of a surface to accept bonding or coatings. 1 fig

  9. Residual stresses

    International Nuclear Information System (INIS)

    Macherauch, E.

    1978-01-01

    Residual stresses are stresses which exist in a material without the influence of external powers and moments. They come into existence when the volume of a material constantly changes its form as a consequence of mechanical, thermal, and/or chemical processes and is hindered by neighbouring volumes. Bodies with residual stress are in mechanical balance. These residual stresses can be manifested by means of all mechanical interventions disturbing this balance. Acoustical, optical, radiological, and magnetical methods involving material changes caused by residual stress can also serve for determining residual stress. Residual stresses have an ambivalent character. In technical practice, they are feared and liked at the same time. They cause trouble because they can be the cause for unexpected behaviour of construction elements. They are feared since they can cause failure, in the worst case with catastrophical consequences. They are appreciated, on the other hand, because, in many cases, they can contribute to improvements of the material behaviour under certain circumstances. But they are especially liked for their giving convenient and (this is most important) mostly uncontrollable explanations. For only in very few cases we have enough knowledge and possibilities for the objective evaluation of residual stresses. (orig.) [de

  10. Tritium plume dynamics in the shallow unsaturated zone in an arid environment

    Science.gov (United States)

    Maples, S.R.; Andraski, Brian J.; Stonestrom, David A.; Cooper, C.A.; Pohll, G.; Michel, R.L.

    2014-01-01

    The spatiotemporal variability of a tritium plume in the shallow unsaturated zone and the mechanisms controlling its transport were evaluated during a 10-yr study. Plume movement was minimal and its mass declined by 68%. Upward-directed diffusive-vapor tritium fluxes and radioactive decay accounted for most of the observed plume-mass declines.Effective isolation of tritium (3H) and other contaminants at waste-burial facilities requires improved understanding of transport processes and pathways. Previous studies documented an anomalously widespread (i.e., theoretically unexpected) distribution of 3H (>400 m from burial trenches) in a dry, sub-root-zone gravelly layer (1–2-m depth) adjacent to a low-level radioactive waste (LLRW) burial facility in the Amargosa Desert, Nevada, that closed in 1992. The objectives of this study were to: (i) characterize long-term, spatiotemporal variability of 3H plumes; and (ii) quantify the processes controlling 3H behavior in the sub-root-zone gravelly layer beneath native vegetation adjacent to the facility. Geostatistical methods, spatial moment analyses, and mass flux calculations were applied to a spatiotemporally comprehensive, 10-yr data set (2001–2011). Results showed minimal bulk-plume advancement during the study period and limited Fickian spreading of mass. Observed spreading rates were generally consistent with theoretical vapor-phase dispersion. The plume mass diminished more rapidly than would be expected from radioactive decay alone, indicating net efflux from the plume. Estimates of upward 3H efflux via diffusive-vapor movement were >10× greater than by dispersive-vapor or total-liquid movement. Total vertical fluxes were >20× greater than lateral diffusive-vapor fluxes, highlighting the importance of upward migration toward the land surface. Mass-balance calculations showed that radioactive decay and upward diffusive-vapor fluxes contributed the majority of plume loss. Results indicate that plume losses

  11. Identifying key controls on the behavior of an acidic-U(VI) plume in the Savannah River Site using reactive transport modeling.

    Science.gov (United States)

    Bea, Sergio A; Wainwright, Haruko; Spycher, Nicolas; Faybishenko, Boris; Hubbard, Susan S; Denham, Miles E

    2013-08-01

    and Al concentrations at multiple locations. Mineral dissolution and precipitation combined with adsorption reactions on goethite and kaolinite (the main minerals present with quartz) could buffer pH at the site for long periods of time. UQ analysis using the Morris one-at-a-time (OAT) method indicates that the model/parameter is most sensitive to the pH of the waste solution, discharge rates, and the reactive surface area available for adsorption. However, as a key finding, UQ analysis also indicates that this model (and parameters) sensitivity evolves in space and time, and its understanding could be crucial to assess the temporal efficiency of a remediation strategy in contaminated sites. Results also indicate that residual U(VI) and H(+) adsorbed in the vadose zone, as well as aquifer permeability, could have a significant impact on the acidic plume long-term mobility. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    Ventilation systems with vertical displacement flow have been used in industrial areas with extensive heat loads for many years. Hot and contaminant air is carried directly from the occupied zone towards the ceiling by hot processes and other activities which create a natural convection flow....

  13. DSMC Simulations of Io's Pele Plume

    Science.gov (United States)

    McDoniel, William; Goldstein, D.; Varghese, P.; Trafton, L.

    2012-10-01

    Io’s Pele plume rises over 300km in altitude and leaves a deposition ring 1200km across on the surface of the moon. Material emerges from an irregularly-shaped vent, and this geometry gives rise to complex 3D flow features. The Direct Simulation Monte Carlo method is used to model the gas flow in the rarefied plume, demonstrating how the geometry of the source region is responsible for the asymmetric structure of the deposition ring and illustrating the importance of very small-scale vent geometry in explaining large observed features of interest. Simulations of small particles in the plume and comparisons to the black “butterfly wings” seen at Pele are used to constrain particle sizes and entrainment mechanisms. Preliminary results for the effects of plasma energy and momentum transfer to the plume will also be presented.

  14. Discovery, interception, and treatment of a groundwater plume: Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Lee, R.; Ketelle, D.

    1996-01-01

    A radiological groundwater plume was discovered to be discharging into a surface stream and portions of the storm drain network at Oak Ridge National Laboratory (ORNL). A CERCLA removal action was initiated to address the discharges. The plume was found to be migrating 65 degrees oblique to the overall hydraulic gradient and was identified only after historic data were analyzed and field tests were performed under the working hypothesis of stratabound flow and transport. A detailed geologic and hydrologic analysis was performed that accurately predicted the 3-dimensional plume configuration from a single point datum where significantly elevated contaminant levels were found in a bedrock core hole. Subsequent sampling found that direct discharges of contamination existed in the stream only in the location of the predicted stratum. The affected storm drain outfall discharges were suspected to be the major contributors to 90 Sr surface water risk from ORNL. Thus, the selected removal action focused on eliminating the known seepage to the storm drain network. Intercept system operations reduced the total surface water 90 Sr flux by about 90%. Ongoing investigations seek to identify the source of the plume with the hope that the intercept system may eventually be deactivated. However, the efficiency of the system exceeded expectations and demonstrated that a good understanding of the hydrodynamics is a prerequisite to success. The relatively trouble free operation of the system also indicates that simple technologies can serve as effective measures to address immediate problems

  15. Fire analog: a comparison between fire plumes and energy center cooling tower plumes

    Energy Technology Data Exchange (ETDEWEB)

    Orgill, M.M.

    1977-10-01

    Thermal plumes or convection columns associated with large fires are compared to thermal plumes from cooling towers and proposed energy centers to evaluate the fire analog concept. Energy release rates of mass fires are generally larger than for single or small groups of cooling towers but are comparable to proposed large energy centers. However, significant physical differences exist between cooling tower plumes and fire plumes. Cooling tower plumes are generally dominated by ambient wind, stability and turbulence conditions. Fire plumes, depending on burning rates and other factors, can transform into convective columns which may cause the fire behavior to become more violent. This transformation can cause strong inflow winds and updrafts, turbulence and concentrated vortices. Intense convective columns may interact with ambient winds to create significant downwind effects such as wakes and Karman vortex streets. These characteristics have not been observed with cooling tower plumes to date. The differences in physical characteristics between cooling tower and fire plumes makes the fire analog concept very questionable even though the approximate energy requirements appear to be satisfied in case of large energy centers. Additional research is suggested in studying the upper-level plume characteristics of small experimental fires so this information can be correlated with similar data from cooling towers. Numerical simulation of fires and proposed multiple cooling tower systems could also provide comparative data.

  16. Diagnostics of laser ablated plasma plumes

    DEFF Research Database (Denmark)

    Amoruso, S.; Toftmann, B.; Schou, Jørgen

    2004-01-01

    The effect of an ambient gas on the expansion dynamics of laser ablated plasmas has been studied for two systems by exploiting different diagnostic techniques. First, the dynamics of a MgB2 laser produced plasma plume in an Ar atmosphere has been investigated by space-and time-resolved optical...... of the laser ablated plasma plume propagation in a background gas. (C) 2003 Elsevier B.V All rights reserved....

  17. Experimental investigation of bubble plume structure instability

    Energy Technology Data Exchange (ETDEWEB)

    Marco Simiano; Robert Zboray; Francois de Cachard [Thermal-Hydraulics Laboratory, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Djamel Lakehal; George Yadigaroglu [Institute of Energy Technology, Swiss Federal Institute of Technology, ETH-Zentrum/CLT, 8092 Zurich (Switzerland)

    2005-07-01

    Full text of publication follows: The hydrodynamic properties of a 3D bubble plume in a large water pool are investigated experimentally. Bubble plumes are present in various industrial processes, including chemical plants, stirred reactors, and nuclear power plants, e.g. in BWR suppression pools. In these applications, the main issue is to predict the currents induced by the bubbles in the liquid phase, and to determine the consequent mixing. Bubble plumes, especially large and unconfined ones, present strong 3D effects and a superposition of different characteristic length scales. Thus, they represent relevant test cases for assessment and verification of 3D models in thermal-hydraulic codes. Bubble plumes are often unsteady, with fluctuations in size and shape of the bubble swarm, and global movements of the plume. In this case, local time-averaged data are not sufficient to characterize the flow. Additional information regarding changes in plume shape and position is required. The effect of scale on the 3D flow structure and stability being complex, there was a need to conduct studies in a fairly large facility, closer to industrial applications. Air bubble plumes, up to 30 cm in base diameter and 2 m in height were extensively studied in a 2 m diameter water pool. Homogeneously sized bubbles were obtained using a particular injector. The main hydrodynamic parameters. i.e., gas and liquid velocities, void fraction, bubble shape and size, plume shape and position, were determined experimentally. Photographic and image processing techniques were used to characterize the bubble shape, and double-tip optical probes to measure bubble size and void fraction. Electromagnetic probes measured the recirculation velocity in the pool. Simultaneous two-phase flow particle image velocimetry (STPFPIV) in a vertical plane containing the vessel axis provided instantaneous velocity fields for both phases and therefore the relative velocity field. Video recording using two CCD

  18. Costs of groundwater contamination

    International Nuclear Information System (INIS)

    O'Neil, W.B.; Raucher, R.S.

    1990-01-01

    Two factors determine the cost of groundwater contamination: (1) the ways in which water was being used or was expected to be used in the future and (2) the physical characteristics of the setting that constrain the responses available to regain lost uses or to prevent related damages to human health and the environment. Most contamination incidents can be managed at a low enough cost that uses will not be foreclosed. It is important to take into account the following when considering costs: (1) natural cleansing through recharge and dilution can take many years; (2) it is difficult and costly to identify the exact area and expected path of a contamination plume; and (3) treatment or replacement of contaminated water often may represent the cost-effective strategy for managing the event. The costs of contamination include adverse health effects, containment and remediation, treatment and replacement costs. In comparing the costs and benefits of prevention programs with those of remediation, replacement or treatment, it is essential to adjust the cost/benefit numbers by the probability of their actual occurrence. Better forecasts of water demand are needed to predict more accurately the scarcity of new supply and the associated cost of replacement. This research should include estimates of the price elasticity of water demand and the possible effect on demand of more rational cost-based pricing structures. Research and development of techniques for in situ remediation should be encouraged

  19. Measurements at cooling tower plumes. Part 3. Three-dimensional measurements at cooling tower plumes

    International Nuclear Information System (INIS)

    Fortak, H.

    An extended field experiment is described in which cooling tower plumes were studied by means of three-dimensional in situ measurements. The goal was to obtain input data for numerical models of cooling tower plumes. Of special interest were data for testing or developing assumptions for sub-grid parametrizations. Utilizing modern systems for high-resolution aerology and small aircraft, four measuring campaigns were conducted: two campaigns (1974) at the cooling towers of the RWE power station Neurath and also two (1975) at the single cooling tower of the RWE power station Meppen. Because of the broad spectrum of weather situations it can be assumed that the results are representative with regard to the interrelationship between structure of cooling tower plume and large-scale meteorological situation. A large number of flights with a powered glider crossing the plumes on orthogonal tracks was performed. All flights showed that the plume could be identified up to large downwind distances by discontinuous jumps of temperature and vapor pressure. Therefore, a definite geometry of the plume could always be defined. In all cross sections a vertical circulation could be observed. At the boundary, which could be defined by the mentioned jumps of temperature and vapor pressure, a maximum of downward vertical motion could be observed in most cases. Entrainment along the boundary of a cross section seems to be very small, except at the lower part of the plume. There, the mass entrainment is maximum and is responsible for plume rise as well as for enlargement of the cross section. The visible part of the plume (cloud) was only a small fraction of the whole plume. High-resolution aerology is necessary in order to explain the structure and behavior of such plumes. This is especially the case in investigations regarding the dynamic break-through of temperature inversions. Such cases were observed frequently under various meteorological conditions and are described

  20. Contaminated Sites by Residues from Romanian Industry

    International Nuclear Information System (INIS)

    Aurelian, F.; Georgescu, D.; Vacariu, V.; Popescu, M.

    2001-01-01

    Full text: In Romania, the mining industries of ferrous ore, non-ferrous ore, bauxite, coal, chemical fertilisers, the extraction of natural gas and oil, etc. have a considerable weight in economy. The study lets us know that in these industries, in different by-products and waste from the process, some radionuclides come out. The preliminary data, which are determined in these industries, are compared with those data, which are published by the countries from EU. There were determined uranium, radium and thorium from ore and sterile (ferrous, non-ferrous, bauxite, talc, clay, asbestos, barytine, salt, coal and bituminous schist). Also, there have been determined the radium and the uranium content of waters from non-uraniferous mining sites. The level of radioactive noxa has been informative determined in each mine. The level of the concentrations requires a systematic research and an assessment of the risk and the impact against the environment, the workers, and the public. (author)

  1. Nuclear thermal rocket plume interactions with spacecraft. Final report

    International Nuclear Information System (INIS)

    Mauk, B.H.; Gatsonis, N.A.; Buzby, J.; Yin, X.

    1997-01-01

    This is the first study that has treated the Nuclear Thermal Rocket (NTR) effluent problem in its entirety, beginning with the reactor core, through the nozzle flow, to the plume backflow. The summary of major accomplishments is given below: (1) Determined the NTR effluents that include neutral, ionized and radioactive species, under typical NTR chamber conditions. Applied an NTR chamber chemistry model that includes conditions and used nozzle geometries and chamber conditions typical of NTR configurations. (2) Performed NTR nozzle flow simulations using a Navier-Stokes solver. We assumed frozen chemistry at the chamber conditions and used nozzle geometries and chamber conditions typical of NTR configurations. (3) Performed plume simulations using a Direct Simulation Monte Carlo (DSMC) code with chemistry. In order to account for radioactive trace species that may be important for contamination purposes we developed a multi-weighted DSMC methodology. The domain in our simulations included large regions downstream and upstream of the exit. Inputs were taken from the Navier-Stokes solutions

  2. Optimized Field Sampling and Monitoring of Airborne Hazardous Transport Plumes; A Geostatistical Simulation Approach

    International Nuclear Information System (INIS)

    Chen, DI-WEN

    2001-01-01

    Airborne hazardous plumes inadvertently released during nuclear/chemical/biological incidents are mostly of unknown composition and concentration until measurements are taken of post-accident ground concentrations from plume-ground deposition of constituents. Unfortunately, measurements often are days post-incident and rely on hazardous manned air-vehicle measurements. Before this happens, computational plume migration models are the only source of information on the plume characteristics, constituents, concentrations, directions of travel, ground deposition, etc. A mobile ''lighter than air'' (LTA) system is being developed at Oak Ridge National Laboratory that will be part of the first response in emergency conditions. These interactive and remote unmanned air vehicles will carry light-weight detectors and weather instrumentation to measure the conditions during and after plume release. This requires a cooperative computationally organized, GPS-controlled set of LTA's that self-coordinate around the objectives in an emergency situation in restricted time frames. A critical step before an optimum and cost-effective field sampling and monitoring program proceeds is the collection of data that provides statistically significant information, collected in a reliable and expeditious manner. Efficient aerial arrangements of the detectors taking the data (for active airborne release conditions) are necessary for plume identification, computational 3-dimensional reconstruction, and source distribution functions. This report describes the application of stochastic or geostatistical simulations to delineate the plume for guiding subsequent sampling and monitoring designs. A case study is presented of building digital plume images, based on existing ''hard'' experimental data and ''soft'' preliminary transport modeling results of Prairie Grass Trials Site. Markov Bayes Simulation, a coupled Bayesian/geostatistical methodology, quantitatively combines soft information

  3. A stakeholder involvement approach to evaluate and enhance technology acceptance: U.S. Department of Energy Office of Technology Development's Plume Focus Area

    International Nuclear Information System (INIS)

    McCabe, G.H.; Stein, S.L.; Serie, P.J.

    1995-01-01

    The US Department of Energy (DOE) faces a major challenge in cleaning up its contaminated sites throughout the United States. One major area of concern is the plumes in soil and ground water which are contaminated with a myriad of different pollutants. DOE recently organized its plume-related problems into the Plume Focus Area. The mission of the Plume Focus Area is to enhance the deployment of innovative technologies for containing and cleaning up contaminant plumes in ground water and soil at all DOE sites. Environmental cleanup priorities for soil and ground water plumes are being defined and technology users have the challenge of matching current and innovative technologies to those priorities. By involving a range of stakeholders in the selection, demonstration, and evaluation of new technologies, the deployment of these technologies can be enhanced. If new plume cleanup technologies are to be deployable, they must improve on today's baseline technologies. The Sites' Coordination Team (SCT) of the Plume Focus Area develops and supports the implementation of methods for stakeholder involvement throughout the multiple steps that define focus area activities. Site-specific teams are being formed to carry out the strategy at each site, and the teams will work through Site Technology Coordination Groups (STCGs) at each location. The SCT is responsible for identifying the site-specific stakeholder involvement teams, training the team members, preparing needed national-level guidance and strategies, helping the teams tailor a strategy for their particular site that meets the overall needs of the focus area, and facilitating inter-site coordination. The results will be used to develop national technology acceptance reports on the innovative technologies being funded and evaluated under the Plume Focus Area

  4. Hubble Captures Volcanic Eruption Plume From Io

    Science.gov (United States)

    1997-01-01

    The Hubble Space Telescope has snapped a picture of a 400-km-high (250-mile-high) plume of gas and dust from a volcanic eruption on Io, Jupiter's large innermost moon.Io was passing in front of Jupiter when this image was taken by the Wide Field and Planetary Camera 2 in July 1996. The plume appears as an orange patch just off the edge of Io in the eight o'clock position, against the blue background of Jupiter's clouds. Io's volcanic eruptions blasts material hundreds of kilometers into space in giant plumes of gas and dust. In this image, material must have been blown out of the volcano at more than 2,000 mph to form a plume of this size, which is the largest yet seen on Io.Until now, these plumes have only been seen by spacecraft near Jupiter, and their detection from the Earth-orbiting Hubble Space Telescope opens up new opportunities for long-term studies of these remarkable phenomena.The plume seen here is from Pele, one of Io's most powerful volcanos. Pele's eruptions have been seen before. In March 1979, the Voyager 1 spacecraft recorded a 300-km-high eruption cloud from Pele. But the volcano was inactive when the Voyager 2 spacecraft flew by Jupiter in July 1979. This Hubble observation is the first glimpse of a Pele eruption plume since the Voyager expeditions.Io's volcanic plumes are much taller than those produced by terrestrial volcanos because of a combination of factors. The moon's thin atmosphere offers no resistance to the expanding volcanic gases; its weak gravity (one-sixth that of Earth) allows material to climb higher before falling; and its biggest volcanos are more powerful than most of Earth's volcanos.This image is a contrast-enhanced composite of an ultraviolet image (2600 Angstrom wavelength), shown in blue, and a violet image (4100 Angstrom wavelength), shown in orange. The orange color probably occurs because of the absorption and/or scattering of ultraviolet light in the plume. This light from Jupiter passes through the plume and is

  5. Long-term natural attenuation of carbon and nitrogen within a groundwater plume after removal of the treated wastewater source.

    Science.gov (United States)

    Repert, Deborah A; Barber, Larry B; Hess, Kathryn M; Keefe, Steffanie H; Kent, Douglas B; LeBlanc, Denis R; Smith, Richard L

    2006-02-15

    Disposal of treated wastewater for more than 60 years onto infiltration beds on Cape Cod, Massachusetts produced a groundwater contaminant plume greater than 6 km long in a surficial sand and gravel aquifer. In December 1995 the wastewater disposal ceased. A long-term, continuous study was conducted to characterize the post-cessation attenuation of the plume from the source to 0.6 km downgradient. Concentrations and total pools of mobile constituents, such as boron and nitrate, steadily decreased within 1-4 years along the transect. Dissolved organic carbon loads also decreased, but to a lesser extent, particularly downgradient of the infiltration beds. After 4 years, concentrations and pools of carbon and nitrogen in groundwater were relatively constant with time and distance, but substantially elevated above background. The contaminant plume core remained anoxic for the entire 10-year study period; temporal patterns of integrated oxygen deficit decreased slowly at all sites. In 2004, substantial amounts of total dissolved carbon (7 mol C m(-2)) and fixed (dissolved plus sorbed) inorganic nitrogen (0.5 mol N m(-2)) were still present in a 28-m vertical interval at the disposal site. Sorbed constituents have contributed substantially to the dissolved carbon and nitrogen pools and are responsible for the long-term persistence of the contaminant plume. Natural aquifer restoration at the discharge location will take at least several decades, even though groundwater flow rates and the potential for contaminant flushing are relatively high.

  6. Pele Plume Deposit on Io

    Science.gov (United States)

    1997-01-01

    The varied effects of Ionian volcanism can be seen in this false color infrared composite image of Io's trailing hemisphere. Low resolution color data from Galileo's first orbit (June, 1996) have been combined with a higher resolution clear filter picture taken on the third orbit (November, 1996) of the spacecraft around Jupiter.A diffuse ring of bright red material encircles Pele, the site of an ongoing, high velocity volcanic eruption. Pele's plume is nearly invisible, except in back-lit photographs, but its deposits indicate energetic ejection of sulfurous materials out to distances more than 600 kilometers from the central vent. Another bright red deposit lies adjacent to Marduk, also a currently active ediface. High temperature hot spots have been detected at both these locations, due to the eruption of molten material in lava flows or lava lakes. Bright red deposits on Io darken and disappear within years or decades of deposition, so the presence of bright red materials marks the sites of recent volcanism.This composite was created from data obtained by the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft. The region imaged is centered on 15 degrees South, 224 degrees West, and is almost 2400 kilometers across. The finest details that can be discerned in this picture are about 3 kilometers across. North is towards the top of the picture and the sun illuminates the surface from the west.The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  7. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for organic contaminants. 141.61 Section 141.61 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER... Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.61 Maximum contaminant...

  8. A method to attenuate U(VI) mobility in acidic waste plumes using humic acids

    Energy Technology Data Exchange (ETDEWEB)

    Wan, J.; Dong, W.; Tokunaga, T.K.

    2011-02-01

    Acidic uranium (U) contaminated plumes have resulted from acid-extraction of plutonium during the Cold War and from U mining and milling operations. A sustainable method for in-situ immobilization of U under acidic conditions is not yet available. Here, we propose to use humic acids (HAs) for in-situ U immobilization in acidic waste plumes. Our laboratory batch experiments show that HA can adsorb onto aquifer sediments rapidly, strongly and practically irreversibly. Adding HA greatly enhanced U adsorption capacity to sediments at pH below 5.0. Our column experiments using historically contaminated sediments from the Savannah River Site under slow flow rates (120 and 12 m/y) show that desorption of U and HA were non-detectable over 100 pore-volumes of leaching with simulated acidic groundwaters. Upon HA-treatment, 99% of the contaminant [U] was immobilized at pH < 4.5, compared to 5% and 58% immobilized in the control columns at pH 3.5 and 4.5, respectively. These results demonstrated that HA-treatment is a promising in-situ remediation method for acidic U waste plumes. As a remediation reagent, HAs are resistant to biodegradation, cost effective, nontoxic, and easily introducible to the subsurface.

  9. The 2016 Case for Mantle Plumes and a Plume-Fed Asthenosphere (Augustus Love Medal Lecture)

    Science.gov (United States)

    Morgan, Jason P.

    2016-04-01

    The process of science always returns to weighing evidence and arguments for and against a given hypothesis. As hypotheses can only be falsified, never universally proved, doubt and skepticism remain essential elements of the scientific method. In the past decade, even the hypothesis that mantle plumes exist as upwelling currents in the convecting mantle has been subject to intense scrutiny; from geochemists and geochronologists concerned that idealized plume models could not fit many details of their observations, and from seismologists concerned that mantle plumes can sometimes not be 'seen' in their increasingly high-resolution tomographic images of the mantle. In the place of mantle plumes, various locally specific and largely non-predictive hypotheses have been proposed to explain the origins of non-plate boundary volcanism at Hawaii, Samoa, etc. In my opinion, this debate has now passed from what was initially an extremely useful restorative from simply 'believing' in the idealized conventional mantle plume/hotspot scenario to becoming an active impediment to our community's ability to better understand the dynamics of the solid Earth. Having no working hypothesis at all is usually worse for making progress than having an imperfect and incomplete but partially correct one. There continues to be strong arguments and strong emerging evidence for deep mantle plumes. Furthermore, deep thermal plumes should exist in a mantle that is heated at its base, and the existence of Earth's (convective) geodynamo clearly indicates that heat flows from the core to heat the mantle's base. Here I review recent seismic evidence by French, Romanowicz, and coworkers that I feel lends strong new observational support for the existence of deep mantle plumes. I also review recent evidence consistent with the idea that secular core cooling replenishes half the mantle's heat loss through its top surface, e.g. that the present-day mantle is strongly bottom heated. Causes for

  10. Plutonium-contaminated fragments at the Taranaki site at Maralinga

    International Nuclear Information System (INIS)

    Burns, P.A.; Cooper, M.B.; Duggleby, J.C.; Mika, J.F.; Williams, G.A.

    1986-07-01

    A detailed assessment is presented of the distribution of plutonium-contaminated fragments and sub-millimetre particles in the vicinity of the Taranaki site at the former U.K. Atomic Weapons Test Range at Maralinga in South Australia. The area which is contaminated with fragments has been divided into three general regions with the designations 'heavily contaminated', 'moderately contaminated' and 'plumes'. The average surface density, activity and estimated total number of fragments are presented for each region. Average surface densities of all fragments with americium-241 activities greater than 2 kBq are estimated to be 33, 7 and 2 m -2 for the 'heavily contaminated', 'moderately contaminated' and 'plumes' regions respectively. The total number of such fragments is estimated to be in excess of three million which accounts for a total plutonium activity of approximately 0.8 TBq. The implications of these results for a rehabilitation program are discussed

  11. Simulating Irregular Source Geometries for Ionian Plumes

    Science.gov (United States)

    McDoniel, W. J.; Goldstein, D. B.; Varghese, P. L.; Trafton, L. M.; Buchta, D. A.; Freund, J.; Kieffer, S. W.

    2011-05-01

    Volcanic plumes on Io respresent a complex rarefied flow into a near-vacuum in the presence of gravity. A 3D Direct Simulation Monte Carlo (DSMC) method is used to investigate the gas dynamics of such plumes, with a focus on the effects of source geometry on far-field deposition patterns. A rectangular slit and a semicircular half annulus are simulated to illustrate general principles, especially the effects of vent curvature on deposition ring structure. Then two possible models for the giant plume Pele are presented. One is a curved line source corresponding to an IR image of a particularly hot region in the volcano's caldera and the other is a large area source corresponding to the entire caldera. The former is seen to produce the features seen in observations of Pele's ring, but with an error in orientation. The latter corrects the error in orientation, but loses some structure. A hybrid simulation of 3D slit flow is also discussed.

  12. Simulating Irregular Source Geometries for Ionian Plumes

    International Nuclear Information System (INIS)

    McDoniel, W. J.; Goldstein, D. B.; Varghese, P. L.; Trafton, L. M.; Buchta, D. A.; Freund, J.; Kieffer, S. W.

    2011-01-01

    Volcanic plumes on Io respresent a complex rarefied flow into a near-vacuum in the presence of gravity. A 3D Direct Simulation Monte Carlo (DSMC) method is used to investigate the gas dynamics of such plumes, with a focus on the effects of source geometry on far-field deposition patterns. A rectangular slit and a semicircular half annulus are simulated to illustrate general principles, especially the effects of vent curvature on deposition ring structure. Then two possible models for the giant plume Pele are presented. One is a curved line source corresponding to an IR image of a particularly hot region in the volcano's caldera and the other is a large area source corresponding to the entire caldera. The former is seen to produce the features seen in observations of Pele's ring, but with an error in orientation. The latter corrects the error in orientation, but loses some structure. A hybrid simulation of 3D slit flow is also discussed.

  13. Atmospheric contamination

    International Nuclear Information System (INIS)

    Gruetter, Juerg

    1997-01-01

    It is about the levels of contamination in center America, the population's perception on the problem, effects of the atmospheric contamination, effects in the environment, causes of the atmospheric contamination, possibilities to reduce the atmospheric contamination and list of Roeco Swisscontac in atmospheric contamination

  14. Kinetic electron model for plasma thruster plumes

    Science.gov (United States)

    Merino, Mario; Mauriño, Javier; Ahedo, Eduardo

    2018-03-01

    A paraxial model of an unmagnetized, collisionless plasma plume expanding into vacuum is presented. Electrons are treated kinetically, relying on the adiabatic invariance of their radial action integral for the integration of Vlasov's equation, whereas ions are treated as a cold species. The quasi-2D plasma density, self-consistent electric potential, and electron pressure, temperature, and heat fluxes are analyzed. In particular, the model yields the collisionless cooling of electrons, which differs from the Boltzmann relation and the simple polytropic laws usually employed in fluid and hybrid PIC/fluid plume codes.

  15. Measurements at cooling tower plumes. Pt. 1

    International Nuclear Information System (INIS)

    Gassmann, F.; Haschke, D.; Solfrian, W.

    1976-04-01

    Referring to the present status of knowledge model conceptions, assumptions and approaches are summarized, which can lead to mathematical models for the simulation of dry or wet cooling tower plumes. By developing a one-dimensional plume model (FOG) the most important problems are considered in detail. It is shown that for the calibration of the necessary parameters as well as for the development of models full scale measurements are of decisive importance. After a discussion of different possibilities of measurement the organisation of a campaign of measurement is described. (orig.) [de

  16. A buoyant plume adjacent to a headland-Observations of the Elwha River plume

    Science.gov (United States)

    Warrick, J.A.; Stevens, A.W.

    2011-01-01

    Small rivers commonly discharge into coastal settings with topographic complexities - such as headlands and islands - but these settings are underrepresented in river plume studies compared to more simplified, straight coasts. The Elwha River provides a unique opportunity to study the effects of coastal topography on a buoyant plume, because it discharges into the Strait of Juan de Fuca on the western side of its deltaic headland. Here we show that this headland induces flow separation and transient eddies in the tidally dominated currents (O(100. cm/s)), consistent with other headlands in oscillatory flow. These flow conditions are observed to strongly influence the buoyant river plume, as predicted by the "small-scale" or "narrow" dynamical classification using Garvine's (1995) system. Because of the transient eddies and the location of the river mouth on the headland, flow immediately offshore of the river mouth is directed eastward twice as frequently as it is westward. This results in a buoyant plume that is much more frequently "bent over" toward the east than the west. During bent over plume conditions, the plume was attached to the eastern shoreline while having a distinct, cuspate front along its westernmost boundary. The location of the front was found to be related to the magnitude and direction of local flow during the preceding O(1. h), and increases in alongshore flow resulted in deeper freshwater mixing, stronger baroclinic anomalies, and stronger hugging of the coast. During bent over plume conditions, we observed significant convergence of river plume water toward the frontal boundary within 1. km of the river mouth. These results show how coastal topography can strongly influence buoyant plume behavior, and they should assist with understanding of initial coastal sediment dispersal pathways from the Elwha River during a pending dam removal project. ?? 2010.

  17. Biodegradation: Updating the Concepts of Control for Microbial Cleanup in Contaminated Aquifers

    DEFF Research Database (Denmark)

    Meckenstock, Rainer U.; Elsner, Martin; Griebler, Christian

    2015-01-01

    Biodegradation is one of the most favored and sustainable means of removing organic pollutants from contaminated aquifers but the major steering factors are still surprisingly poorly understood. Growing evidence questions some of the established concepts for control of biodegradation. Here, we...... on the controls of biodegradation in contaminant plumes. These include the plume fringe concept, transport limitations, and transient conditions as currently underestimated processes affecting biodegradation....

  18. Residual basins

    International Nuclear Information System (INIS)

    D'Elboux, C.V.; Paiva, I.B.

    1980-01-01

    Exploration for uranium carried out over a major portion of the Rio Grande do Sul Shield has revealed a number of small residual basins developed along glacially eroded channels of pre-Permian age. Mineralization of uranium occurs in two distinct sedimentary units. The lower unit consists of rhythmites overlain by a sequence of black shales, siltstones and coal seams, while the upper one is dominated by sandstones of probable fluvial origin. (Author) [pt

  19. Chemical barriers for controlling groundwater contamination

    International Nuclear Information System (INIS)

    Morrison, S.J.; Spangler, R.R.

    1993-01-01

    Chemical barriers are being explored as a low-cost means of controlling groundwater contamination. The barrier can intercept a contaminant plume and prevent migration by transferring contaminants from the groundwater to immobile solids. A chemical barrier can be emplaced in a landfill liner or in an aquifer cutoff wall or can be injected into a contaminant plume. Chemical barriers can be classified as either precipitation barriers or sorption barriers depending upon the dominant mode of contaminant extraction. In a precipitation barrier, contaminants are bound in the structures of newly formed phases; whereas, in a sorption barrier, contaminants attach to the surfaces of preexisting solids by adsorption or some other surface mechanism. Sorption of contaminants is pH dependent. A precipitation barrier can control the pH of the system, but alkaline groundwater may dominate the pH in a sorption barrier. A comparison is made of the characteristics of precipitation and sorption barriers. Experimental data on the extraction of uranium and molybdenum from simulated groundwater are used to demonstrate these concepts. 10 refs., 9 figs., 1 tab

  20. Scaling for turbulent viscosity of buoyant plumes in stratified fluids: PIV measurement with implications for submarine hydrothermal plume turbulence

    Science.gov (United States)

    Zhang, Wei; He, Zhiguo; Jiang, Houshuo

    2017-11-01

    Time-resolved particle image velocimetry (PIV) has been used to measure instantaneous two-dimensional velocity vector fields of laboratory-generated turbulent buoyant plumes in linearly stratified saltwater over extended periods of time. From PIV-measured time-series flow data, characteristics of plume mean flow and turbulence have been quantified. To be specific, maximum plume penetration scaling and entrainment coefficient determined from the mean flow agree well with the theory based on the entrainment hypothesis for buoyant plumes in stratified fluids. Besides the well-known persistent entrainment along the plume stem (i.e., the 'plume-stem' entrainment), the mean plume velocity field shows persistent entrainment along the outer edge of the plume cap (i.e., the 'plume-cap' entrainment), thereby confirming predictions from previous numerical simulation studies. To our knowledge, the present PIV investigation provides the first measured flow field data in the plume cap region. As to measured plume turbulence, both the turbulent kinetic energy field and the turbulence dissipation rate field attain their maximum close to the source, while the turbulent viscosity field reaches its maximum within the plume cap region; the results also show that maximum turbulent viscosity scales as νt,max = 0.030(B/N)1/2, where B is source buoyancy flux and N is ambient buoyancy frequency. These PIV data combined with previously published numerical simulation results have implications for understanding the roles of hydrothermal plume turbulence, i.e. plume turbulence within the cap region causes the 'plume-cap' entrainment that plays an equally important role as the 'plume-stem' entrainment in supplying the final volume flux at the plume spreading level.

  1. Updated Magmatic Flux Rate Estimates for the Hawaii Plume

    Science.gov (United States)

    Wessel, P.

    2013-12-01

    Several studies have estimated the magmatic flux rate along the Hawaiian-Emperor Chain using a variety of methods and arriving at different results. These flux rate estimates have weaknesses because of incomplete data sets and different modeling assumptions, especially for the youngest portion of the chain (little or no quantification of error estimates for the inferred melt flux, making an assessment problematic. Here we re-evaluate the melt flux for the Hawaii plume with the latest gridded data sets (SRTM30+ and FAA 21.1) using several methods, including the optimal robust separator (ORS) and directional median filtering techniques (DiM). We also compute realistic confidence limits on the results. In particular, the DiM technique was specifically developed to aid in the estimation of surface loads that are superimposed on wider bathymetric swells and it provides error estimates on the optimal residuals. Confidence bounds are assigned separately for the estimated surface load (obtained from the ORS regional/residual separation techniques) and the inferred subsurface volume (from gravity-constrained isostasy and plate flexure optimizations). These new and robust estimates will allow us to assess which secondary features in the resulting melt flux curve are significant and should be incorporated when correlating melt flux variations with other geophysical and geochemical observations.

  2. The evolution of photochemical smog in a power plant plume

    Science.gov (United States)

    Luria, Menachem; Valente, Ralph J.; Tanner, Roger L.; Gillani, Noor V.; Imhoff, Robert E.; Mueller, Stephen F.; Olszyna, Kenneth J.; Meagher, James F. Present address: Aeronomy Laboratory, NOAA, 325 Broadway, Boulder CO 80303, USA.)

    The evolution of photochemical smog in a plant plume was investigated with the aid of an instrumented helicopter. Air samples were taken in the plume of the Cumberland Power Plant, located in central Tennessee, during the afternoon of 16 July 1995 as part of the Southern Oxidants Study - Nashville Middle Tennessee Ozone Study. Twelve cross-wind air sampling traverses were made at six distance groups from 35 to 116 km from the source. During the sampling period the winds were from the west-northwest and the plume drifted towards the city of Nashville TN. Ten of the traverses were made upwind of the city, where the power plant plume was isolated, and two traverses downwind of the city when the plumes were possibly mixed. The results revealed that even six hours after the release, excess ozone production was limited to the edges of the plume. Only when the plume was sufficiently dispersed, but still upwind of Nashville, was excess ozone (up to 109 ppbv, 50-60 ppbv above background levels) produced in the center of the plume. The concentrations image of the plume and a Lagrangian particle model suggests that portions of the power plant plume mixed with the urban plume. The mixed urban power plant plume began to regenerate O 3 that peaked at 120 ppbv at a short distance (15-25 km) downwind of Nashville. Ozone productivity (the ratio of excess O 3 to NO y and NO z) in the isolated plume was significantly lower compared with that found in the city plume. The production of nitrate, a chain termination product, was significantly higher in the power plant plume compared to the mixed plume, indicating shorter chain length of the photochemical smog chain reaction mechanism.

  3. The evolution of photochemical smog in a power plant plume

    International Nuclear Information System (INIS)

    Luria, M.; The Hebrew University, Jerusalem; Valente, R.J.; Tanner, R.L.; Imhoff, R.E.; Mueller, S.F.; Olszyna, K.J.; Meagher, J.F.; Gillani, N.V.; University of Alabama, Huntsville, AL

    1999-01-01

    The evolution of photochemical smog in a plant plume was investigated with the aid of an instrumented helicopter. Air samples were taken in the plume of the Cumberland Power Plant, located in central Tennessee, during the afternoon of 16 July 1995 as part of the Southern Oxidants Study - Nashville Middle Tennessee Ozone Study. Twelve cross-wind air sampling traverses were made at six distance groups from 35 to 116 km from the source. During the sampling period the winds were from the west-northwest and the plume drifted towards the city of Nashville TN. Ten of the traverses were made upwind of the city, where the power plant plume was isolated, and two traverses downwind of the city when the plumes were possibly mixed. The results revealed that even six hours after the release, excess ozone production was limited to the edges of the plume. Only when the plume was sufficiently dispersed, but still upwind of Nashville, was excess ozone (up to 109 ppbv, 50-60 ppbv above background levels) produced in the center of the plume. The concentrations image of the plume and a Lagrangian particle model suggests that portions of the power plant plume mixed with the urban plume. The mixed urban power plant plume began to regenerate O 3 that peaked at 120 ppbv at a short distance (15-25 km) downwind of Nashville. Ozone productivity (the ratio of excess O 3 to NO y and NO z ) in the isolated plume was significantly lower compared with that found in the city plume. The production of nitrate, a chain termination product, was significantly higher in the power plant plume compared to the mixed plume, indicating shorter chain length of the photochemical smog chain reaction mechanism. (author)

  4. Smoke plume behavior - what the data say

    Science.gov (United States)

    Gary L. Achtemeier; Luke Naeher

    2005-01-01

    a comprehensive smoke project, now ongoing for four years, is designed in part to investigate plume behavior from southern prescribed burns with respect to atmospheric stability and to document ground-level smoke concentrations with PM2.5 data from a network of samplers specially constructed for the project. Project management goals are to find ways to increase the...

  5. Dispersion of Chernobyl radioactive plume over Europe

    International Nuclear Information System (INIS)

    Albergel, A.

    1988-01-01

    A long-range pollutant transport and removal model, is used to analyse the Chernobyl radioactive plume dispersion over the Europe Continent. Model predictions are compared to field measurements of Cs-137 activity in the air from April 26th, to May 5th 1986 [fr

  6. Reed Watkins: A Passion for Plume Moths

    Science.gov (United States)

    Reed Watkins has curated the nationl Pterophordiae or plume moth collection at the National Museum of Natural History, Smithsonian Institution, for the past 13 years. He has decreased the number of specimens of unsorted and unidentified material and has expanded the collection from 3 to 6 cabinets....

  7. Ablation plume dynamics in a background gas

    DEFF Research Database (Denmark)

    Amoruso, Salvatore; Schou, Jørgen; Lunney, James G.

    2010-01-01

    The expansion of a plume in a background gas of pressure comparable to that used in pulsed laser deposition (PLD) has been analyzed in terms of the model of Predtechensky and Mayorov (PM). This approach gives a relatively clear and simple description of the essential hydrodynamics during the expa......The expansion of a plume in a background gas of pressure comparable to that used in pulsed laser deposition (PLD) has been analyzed in terms of the model of Predtechensky and Mayorov (PM). This approach gives a relatively clear and simple description of the essential hydrodynamics during...... the expansion. The model also leads to an insightful treatment of the stopping behavior in dimensionless units for plumes and background gases of different atomic/molecular masses. The energetics of the plume dynamics can also be treated with this model. Experimental time-of-flight data of silver ions in a neon...... background gas show a fair agreement with predictions from the PM-model. Finally we discuss the validity of the model, if the work done by the pressure of the background gas is neglected....

  8. Environmental dredging residual generation and management.

    Science.gov (United States)

    Patmont, Clay; LaRosa, Paul; Narayanan, Raghav; Forrest, Casey

    2018-05-01

    The presence and magnitude of sediment contamination remaining in a completed dredge area can often dictate the success of an environmental dredging project. The need to better understand and manage this remaining contamination, referred to as "postdredging residuals," has increasingly been recognized by practitioners and investigators. Based on recent dredging projects with robust characterization programs, it is now understood that the residual contamination layer in the postdredging sediment comprises a mixture of contaminated sediments that originate from throughout the dredge cut. This mixture of contaminated sediments initially exhibits fluid mud properties that can contribute to sediment transport and contamination risk outside of the dredge area. This article reviews robust dredging residual evaluations recently performed in the United States and Canada, including the Hudson River, Lower Fox River, Ashtabula River, and Esquimalt Harbour, along with other projects. These data better inform the understanding of residuals generation, leading to improved models of dredging residual formation to inform remedy evaluation, selection, design, and implementation. Data from these projects confirm that the magnitude of dredging residuals is largely determined by site conditions, primarily in situ sediment fluidity or liquidity as measured by dry bulk density. While the generation of dredging residuals cannot be avoided, residuals can be successfully and efficiently managed through careful development and implementation of site-specific management plans. Integr Environ Assess Manag 2018;14:335-343. © 2018 The Authors. Integrated Environmental Assessment and Management Published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC). © 2018 The Authors. Integrated Environmental Assessment and Management Published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

  9. In-situ treatment of a mixed hydrocarbon plume through a permeable reactive barrier and enhanced bio-remediation

    International Nuclear Information System (INIS)

    Aglietto, I.; Bretti, L.L.

    2005-01-01

    Groundwater is frequently polluted with mixtures of contaminants that are amenable to different types of remediation. One example is the combination of petroleum hydrocarbons (mostly BTEX) and chlorinated solvents (chlorinated ethenes and propanes), as it occurs in the groundwater beneath the industrial site that is the objective of the present case study. The site is located in Italy near a main river (Arno), which is supposed to be the final recipient of the contamination and where a possible exposure might take place. The aim of the treatment is the plume containment within the site boundaries in order to avoid further migration of the contaminants towards the river. The design of the remediation system was based on an extensive site characterization that included - but was not limited to - the following information: geological and geochemical, microbiological and hydrological data, together with analytical data (i.e. contaminant concentrations). Pilot tests were also implemented in order to collect the necessary parameters for the full-scale treatment design and calibration. The site was contaminated by a mixed plume of more than 30 different contaminants, ranging from BTEX, to MTBE, to PAH, to chlorinated solvents. The concentration peaks were in the order of 1-100 mg/l for each contaminant. Petroleum hydrocarbons are quickly degradable through oxidative mechanisms (especially aerobic biodegradation), whereas fully-chlorinated compounds are only degradable via reductive pathways. A mixed plume of both types of contaminants therefore requires a combined approach with the application of different treatment technologies. The remediation strategy elaborated combines a permeable reactive barrier (PRB) in a funnel and gate configuration for the down-gradient plume containment, with the enhanced bio-remediation of the contaminants for the control of the plume boundaries and for the abatement of the concentration peaks. Pilot tests were carried out in order to assess

  10. Geoelectrical mapping and groundwater contamination

    Science.gov (United States)

    Blum, Rainer

    Specific electrical resistivity of near-surface materials is mainly controlled by the groundwater content and thus reacts extremely sensitive to any change in the ion content. Geoelectric mapping is a well-established, simple, and inexpensive technique for observing areal distributions of apparent specific electrical resistivities. These are a composite result of the true resistivities in the underground, and with some additional information the mapping of apparent resistivities can help to delineate low-resistivity groundwater contaminations, typically observed downstream from sanitary landfills and other waste sites. The presence of other good conductors close to the surface, mainly clays, is a serious noise source and has to be sorted out by supporting observations of conductivities in wells and geoelectric depth soundings. The method may be used to monitor the extent of groundwater contamination at a specific time as well as the change of a contamination plume with time, by carrying out repeated measurements. Examples for both are presented.

  11. Evaluation of plume potential and plume abatement of evaporative cooling towers in a subtropical region

    International Nuclear Information System (INIS)

    Xu Xinhua; Wang Shengwei; Ma Zhenjun

    2008-01-01

    Hong Kong is a typical subtropical region with frequently high humidity in late spring and summer seasons. Plume from evaporative cooling towers, which service air-conditioning systems of civil buildings, has aroused public concerns since 2000 when the fresh water evaporative cooling towers were allowed to be used for high energy efficiency and environmental issues. This paper presents the evaluation of the plume potential and its effect on the sizing of the plume abatement system in a large commercial office building in Hong Kong for practical application. This evaluation was conducted based on a dynamic simulation platform using the typical meteorological year of Hong Kong since the occurrence of the plume heavily depends on the state conditions of the exhaust air from cooling towers and the ambient air, while the state condition of the exhaust air is determined by the total building cooling load and the control strategies of cooling towers employed mainly for improving energy efficiency. The results show that the control strategies have a significant effect on the plume potential and further affect the system design and sizing of the plume abatement system

  12. Subsurface Contamination Focus Area technical requirements. Volume 1: Requirements summary

    International Nuclear Information System (INIS)

    Nickelson, D.; Nonte, J.; Richardson, J.

    1996-10-01

    This document summarizes functions and requirements for remediation of source term and plume sites identified by the Subsurface Contamination Focus Area. Included are detailed requirements and supporting information for source term and plume containment, stabilization, retrieval, and selective retrieval remedial activities. This information will be useful both to the decision-makers within the Subsurface Contamination Focus Area (SCFA) and to the technology providers who are developing and demonstrating technologies and systems. Requirements are often expressed as graphs or charts, which reflect the site-specific nature of the functions that must be performed. Many of the tradeoff studies associated with cost savings are identified in the text

  13. Plume-induced stress in pulsed-laser deposited CeO2 films

    International Nuclear Information System (INIS)

    Norton, D.P.; Park, C.; Budai, J.D.; Pennycook, S.J.; Prouteau, C.

    1999-01-01

    Residual compressive stress due to plume-induced energetic particle bombardment in CeO 2 films deposited by pulsed-laser deposition is reported. For laser ablation film growth in low pressures, stresses as high as 2 GPa were observed as determined by substrate curvature and four-circle x-ray diffraction. The amount of stress in the films could be manipulated by controlling the kinetic energies of the ablated species in the plume through gas-phase collisions with an inert background gas. The film stress decreased to near zero for argon background pressures greater than 50 mTorr. At these higher background pressures, the formation of nanoparticles in the deposited film was observed. copyright 1999 American Institute of Physics

  14. An Approach Using Gas Monitoring to Find the Residual TCE Location in the Unsaturated Zone of Woosan Industrial Complex (WIC), Korea

    Science.gov (United States)

    Koh, Y.; Lee, S.; Yang, J.; Lee, K.

    2012-12-01

    An area accommodating various industrial facilities has fairly high probability of groundwater contamination with multiple chlorinated solvents such as trichloroethene (TCE), carbon tetrachloride (CT), and chloroform (CF). Source tracing of chlorinated solvents in the unsaturated zone is an essential procedure for the management and remediation of contaminated area. From the previous study on seasonal variations in hydrological stresses and spatial variations in geologic conditions on a TCE plume, the existence of residual DNAPLs at or above the water table has proved. Since TCE is one of the frequently detected VOCs (Volatile Organic Compounds) in groundwater, residual TCE can be detected by gas monitoring. Therefore, monitoring of temporal and spatial variations in the gas phase TCE contaminant at an industrial complex in Wonju, Korea, were used to find the residual TCE locations. As pilot tests, TCE gas samples collected in the unsaturated zone at 4 different wells were analyzed using SPME (Solid Phase MicroExtraction) fiber and Gas Chromatography (GC). The results indicated that detecting TCE in gas phase was successful from these wells and TCE analysis on gas samples, collected from the unsaturated zone, will be useful for source area characterization. However, some values were too high to doubt the accuracy of the current method, which needs a preliminary lab test with known concentrations. The modified experiment setups using packer at different depths are in process to find residual TCE locations in the unsaturated zone. Meanwhile, several PVD (polyethylene-membrane Passive Vapor Diffusion) samplers were placed under water table to detect VOCs by equilibrium between air in the vial and VOCs in pore water.

  15. The value of DCIP geophysical surveys for contaminated site investigations

    DEFF Research Database (Denmark)

    Balbarini, Nicola; Rønde, Vinni Kampman; Maurya, Pradip Kumar

    an old factory site by combining traditional geological, hydrological, and contaminant concentration data with DCIP surveys. The plume consisted of xenobiotic organic compounds and inorganics. The study assesses benefits and limitations of DCIP geophysics for contaminated site investigations. A 3D......Geophysical methods are increasingly being used in contaminant hydrogeology to map lithology, hydraulic properties, and contaminant plumes with a high ionic strength. Advances in the Direct Current resistivity and Induced Polarization (DCIP) method allow the collection of high resolution three...... water and below the streambed. Surface DCIP surveys supported the characterization of the spatial variability in geology, hydraulic conductivity and contaminant concentration. Though DCIP data interpretation required additional borehole data, the DCIP survey reduced the number of boreholes required...

  16. A mass balance approach to investigate arsenic cycling in a petroleum plume.

    Science.gov (United States)

    Ziegler, Brady A; Schreiber, Madeline E; Cozzarelli, Isabelle M; Crystal Ng, G-H

    2017-12-01

    Natural attenuation of organic contaminants in groundwater can give rise to a series of complex biogeochemical reactions that release secondary contaminants to groundwater. In a crude oil contaminated aquifer, biodegradation of petroleum hydrocarbons is coupled with the reduction of ferric iron (Fe(III)) hydroxides in aquifer sediments. As a result, naturally occurring arsenic (As) adsorbed to Fe(III) hydroxides in the aquifer sediment is mobilized from sediment into groundwater. However, Fe(III) in sediment of other zones of the aquifer has the capacity to attenuate dissolved As via resorption. In order to better evaluate how long-term biodegradation coupled with Fe-reduction and As mobilization can redistribute As mass in contaminated aquifer, we quantified mass partitioning of Fe and As in the aquifer based on field observation data. Results show that Fe and As are spatially correlated in both groundwater and aquifer sediments. Mass partitioning calculations demonstrate that 99.9% of Fe and 99.5% of As are associated with aquifer sediment. The sediments act as both sources and sinks for As, depending on the redox conditions in the aquifer. Calculations reveal that at least 78% of the original As in sediment near the oil has been mobilized into groundwater over the 35-year lifespan of the plume. However, the calculations also show that only a small percentage of As (∼0.5%) remains in groundwater, due to resorption onto sediment. At the leading edge of the plume, where groundwater is suboxic, sediments sequester Fe and As, causing As to accumulate to concentrations 5.6 times greater than background concentrations. Current As sinks can serve as future sources of As as the plume evolves over time. The mass balance approach used in this study can be applied to As cycling in other aquifers where groundwater As results from biodegradation of an organic carbon point source coupled with Fe reduction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Plume collimation for laser ablation electrospray ionization mass spectrometry

    Science.gov (United States)

    Vertes, Akos; Stolee, Jessica A.

    2014-09-09

    In various embodiments, a device may generally comprise a capillary having a first end and a second end; a laser to emit energy at a sample in the capillary to ablate the sample and generate an ablation plume in the capillary; an electrospray apparatus to generate an electrospray plume to intercept the ablation plume to produce ions; and a mass spectrometer having an ion transfer inlet to capture the ions. The ablation plume may comprise a collimated ablation plume. The device may comprise a flow cytometer. Methods of making and using the same are also described.

  18. Plume meander and dispersion in a stable boundary layer

    Science.gov (United States)

    Hiscox, April L.; Miller, David R.; Nappo, Carmen J.

    2010-11-01

    Continuous lidar measurements of elevated plume dispersion and corresponding micrometeorology data are analyzed to establish the relationship between plume behavior and nocturnal boundary layer dynamics. Contrasting nights of data from the JORNADA field campaign in the New Mexico desert are analyzed. The aerosol lidar measurements were used to separate the plume diffusion (plume spread) from plume meander (displacement). Mutiresolution decomposition was used to separate the turbulence scale (90 s). Durations of turbulent kinetic energy stationarity and the wind steadiness were used to characterize the local scale and submesoscale turbulence. Plume meander, driven by submesoscale wind motions, was responsible for most of the total horizontal plume dispersion in weak and variable winds and strong stability. This proportion was reduced in high winds (i.e., >4 m s-1), weakly stable conditions but remained the dominant dispersion mechanism. The remainder of the plume dispersion in all cases was accounted for by internal spread of the plume, which is a small eddy diffusion process driven by turbulence. Turbulence stationarity and the wind steadiness are demonstrated to be closely related to plume diffusion and plume meander, respectively.

  19. Are splash plumes the origin of minor hotspots?

    Science.gov (United States)

    Davies, J. H.; Bunge, H.-P.

    2006-05-01

    It has been claimed that focused hot cylindrical upwelling plumes cause many of the surface volcanic hotspots on Earth. It has also been argued that they must originate from thermal boundary layers. In this paper, we present spherical simulations of mantle circulation at close to Earth-like vigor with significant internal heating. These show, in addition to thermal boundary layer plumes, a new class of plumes that are not rooted in thermal boundary layers. These plumes develop as instabilities from the edge of bowls of hot mantle, which are produced by cold downwelling material deforming hot sheets of mantle. The resulting bowl and plume structure can look a bit like the “splash” of a water droplet. These splash plumes might provide an explanation for some hotspots that are not underlain by thermal boundary layer sourced plumes and not initiated by large igneous provinces. We suggest that in Earth's mantle, lithospheric instabilities or small pieces of subducting slab could play the role of the model downwelling material in initiating splash plumes. Splash plumes would have implications for interpreting ocean-island basalt geochemistry, plume fixity, excess plume temperature, and estimating core heat flux. Improved seismic imaging will ultimately test this hypothesis.

  20. Analysis of Aquifer Response, Groundwater Flow, and PlumeEvolution at Site OU 1, Former Fort Ord, California

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Preston D.; Oldenburg, Curtis M.; Su, Grace W.

    2005-02-24

    This report presents a continuation from Oldenburg et al. (2002) of analysis of the hydrogeology, In-Situ Permeable Flow Sensor (ISPFS) results, aquifer response, and changes in the trichloroethylene (TCE) groundwater plume at Operational Unit 1 (OU 1) adjacent to the former Fritzsche Army Airfield at the former Fort Ord Army Base, located on Monterey Bay in northern Monterey County. Fuels and solvents were burned on a portion of OU 1 called the Fire Drill Area (FDA) during airport fire suppression training between 1962 and 1985. This activity resulted in soil and groundwater contamination in the unconfined A-aquifer. In the late 1980's, soil excavation and bioremediation were successful in remediating soil contamination at the site. Shortly thereafter, a groundwater pump, treat, and recharge system commenced operation. This system has been largely successful at remediating groundwater contamination at the head of the groundwater plume. However, a trichloroethylene (TCE) groundwater plume extends approximately 3000 ft (900 m) to the northwest away from the FDA. In the analyses presented here, we augment our prior work (Oldenburg et al., 2002) with new information including treatment-system totalizer data, recent water-level and chemistry data, and data collected from new wells to discern trends in contaminant migration and groundwater flow that may be useful for ongoing remediation efforts. Some conclusions from the prior study have been modified based on these new analyses, and these are pointed out clearly in this report.

  1. Residue management at Rocky Flats

    International Nuclear Information System (INIS)

    Olencz, J.

    1995-01-01

    Past plutonium production and manufacturing operations conducted at the Rocky Flats Environmental Technology Site (RFETS) produced a variety of plutonium-contaminated by-product materials. Residues are a category of these materials and were categorized as open-quotes materials in-processclose quotes to be recovered due to their inherent plutonium concentrations. In 1989 all RFETS plutonium production and manufacturing operations were curtailed. This report describes the management of plutonium bearing liquid and solid wastes

  2. Characterization of DNAPL Source Zone Architecture and Prediction of Associated Plume Response: Progress and Perspectives

    Science.gov (United States)

    Abriola, L. M.; Pennell, K. D.; Ramsburg, C. A.; Miller, E. L.; Christ, J.; Capiro, N. L.; Mendoza-Sanchez, I.; Boroumand, A.; Ervin, R. E.; Walker, D. I.; Zhang, H.

    2012-12-01

    It is now widely recognized that the distribution of contaminant mass will control both the evolution of aqueous phase plumes and the effectiveness of many source zone remediation technologies at sites contaminated by dense nonaqueous phase liquids (DNAPLs). Advances in the management of sites containing DNAPL source zones, however, are currently hampered by the difficulty associated with characterizing subsurface DNAPL 'architecture'. This presentation provides an overview of recent research, integrating experimental and mathematical modeling studies, designed to improve our ability to characterize DNAPL distributions and predict associated plume response. Here emphasis is placed on estimation of the most information-rich DNAPL architecture metrics, through a combination of localized in situ tests and more readily available plume transect concentration observations. Estimated metrics will then serve as inputs to an upscaled screening model for prediction of long term plume response. Machine learning techniques were developed and refined to identify a variety of source zone metrics and associated confidence intervals through the processing of down gradient concentration data. Estimated metrics include the volumes and volume percentages of DNAPL in pools and ganglia, as well as their ratio (pool fraction). Multiphase flow and transport simulations provided training data for model development and assessment that are representative of field-scale DNAPL source zones and their evolving plumes. Here, a variety of release and site heterogeneity (sequential Gaussian permeability) conditions were investigated. Push-pull tracer tests were also explored as a means to provide localized in situ observations to refine these metric estimates. Here, two-dimensional aquifer cell experiments and mathematical modeling were used to quantify upscaled interphase mass transfer rates and the interplay between injection and extraction rates, local source zone architecture, and tracer

  3. Role of back diffusion and biodegradation reactions in sustaining an MTBE/TBA plume in alluvial media.

    Science.gov (United States)

    Rasa, Ehsan; Chapman, Steven W; Bekins, Barbara A; Fogg, Graham E; Scow, Kate M; Mackay, Douglas M

    2011-11-01

    A methyl tert-butyl ether (MTBE) / tert-butyl alcohol (TBA) plume originating from a gasoline spill in late 1994 at Vandenberg Air Force Base (VAFB) persisted for over 15 years within 200 feet of the original spill source. The plume persisted until 2010 despite excavation of the tanks and piping within months after the spill and excavations of additional contaminated sediments from the source area in 2007 and 2008. The probable history of MTBE concentrations along the plume centerline at its source was estimated using a wide variety of available information, including published details about the original spill, excavations and monitoring by VAFB consultants, and our own research data. Two-dimensional reactive transport simulations of MTBE along the plume centerline were conducted for a 20-year period following the spill. These analyses suggest that MTBE diffused from the thin anaerobic aquifer into the adjacent anaerobic silts and transformed to TBA in both aquifer and silt layers. The model reproduces the observation that after 2004 TBA was the dominant solute, diffusing back out of the silts into the aquifer and sustaining plume concentrations much longer than would have been the case in the absence of such diffusive exchange. Simulations also suggest that aerobic degradation of MTBE or TBA at the water table in the overlying silt layer significantly affected concentrations of MTBE and TBA by limiting the chemical mass available for back diffusion to the aquifer. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Residual nilpotence and residual solubility of groups

    International Nuclear Information System (INIS)

    Mikhailov, R V

    2005-01-01

    The properties of the residual nilpotence and the residual solubility of groups are studied. The main objects under investigation are the class of residually nilpotent groups such that each central extension of these groups is also residually nilpotent and the class of residually soluble groups such that each Abelian extension of these groups is residually soluble. Various examples of groups not belonging to these classes are constructed by homological methods and methods of the theory of modules over group rings. Several applications of the theory under consideration are presented and problems concerning the residual nilpotence of one-relator groups are considered.

  5. 40 CFR 141.62 - Maximum contaminant levels for inorganic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for inorganic contaminants. 141.62 Section 141.62 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.62 Maximum...

  6. 40 CFR 141.63 - Maximum contaminant levels (MCLs) for microbiological contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels (MCLs) for microbiological contaminants. 141.63 Section 141.63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.63 Maximum...

  7. Actinide recovery from pyrochemical residues

    International Nuclear Information System (INIS)

    Avens, L.R.; Clifton, D.G.; Vigil, A.R.

    1984-01-01

    A new process for recovery of plutonium and americium from pyrochemical waste has been demonstrated. It is based on chloride solution anion exchange at low acidity, which eliminates corrosive HCl fumes. Developmental experiments of the process flowsheet concentrated on molten salt extraction (MSE) residues and gave >95% plutonium and >90% americium recovery. The recovered plutonium contained 6 = from high chloride-low acid solution. Americium and other metals are washed from the ion exchange column with 1N HNO 3 -4.8M NaCl. The plutonium is recovered, after elution, via hydroxide precipitation, while the americium is recovered via NaHCO 3 precipitation. All filtrates from the process are discardable as low-level contaminated waste. Production-scale experiments are now in progress for MSE residues. Flow sheets for actinide recovery from electrorefining and direct oxide reduction residues are presented and discussed

  8. Actinide recovery from pyrochemical residues

    International Nuclear Information System (INIS)

    Avens, L.R.; Clifton, D.G.; Vigil, A.R.

    1985-05-01

    We demonstrated a new process for recovering plutonium and americium from pyrochemical waste. The method is based on chloride solution anion exchange at low acidity, or acidity that eliminates corrosive HCl fumes. Developmental experiments of the process flow chart concentrated on molten salt extraction (MSE) residues and gave >95% plutonium and >90% americium recovery. The recovered plutonium contained 6 2- from high-chloride low-acid solution. Americium and other metals are washed from the ion exchange column with lN HNO 3 -4.8M NaCl. After elution, plutonium is recovered by hydroxide precipitation, and americium is recovered by NaHCO 3 precipitation. All filtrates from the process can be discardable as low-level contaminated waste. Production-scale experiments are in progress for MSE residues. Flow charts for actinide recovery from electro-refining and direct oxide reduction residues are presented and discussed

  9. River Plumes in Sunglint, Sarawak, Borneo

    Science.gov (United States)

    1991-01-01

    The sunglint pattern along the coast of Sarawak (3.0N, 111.5E) delineates the boundry of fresh water river plumes as they flow into the South China Sea. The fresh water lens (boundry between fresh and sea water) overides the saline and more dense sea water and oils, both natural and man made, collect along the convergence zones and dampen wave action. As a result, the smoother sea surface appears bright in the sunglint pattern.

  10. Turbulent structure of thermal plume. Velocity field

    International Nuclear Information System (INIS)

    Guillou, B.; Brahimi, M.; Doan-kim-son

    1986-01-01

    An experimental investigation and a numerical study of the dynamics of a turbulent plume rising from a strongly heated source are described. This type of flow is met in thermal effluents (air, vapor) from, e.g., cooling towers of thermal power plants. The mean and fluctuating values of the vertical component of the velocity were determined using a Laser-Doppler anemometer. The measurements allow us to distinguish three regions in the plume-a developing region near the source, an intermediate region, and a self-preserving region. The characteristics of each zone have been determined. In the self-preserving zone, especially, the turbulence level on the axis and the entrainment coefficient are almost twice of the values observed in jets. The numerical model proposed takes into account an important phenomenon, the intermittency, observed in the plume. This model, established with the self-preserving hypothesis, brings out analytical laws. These laws and the predicted velocity profile are in agreement with the experimental evolutions [fr

  11. Numerical model simulation of atmospheric coolant plumes

    International Nuclear Information System (INIS)

    Gaillard, P.

    1980-01-01

    The effect of humid atmospheric coolants on the atmosphere is simulated by means of a three-dimensional numerical model. The atmosphere is defined by its natural vertical profiles of horizontal velocity, temperature, pressure and relative humidity. Effluent discharge is characterised by its vertical velocity and the temperature of air satured with water vapour. The subject of investigation is the area in the vicinity of the point of discharge, with due allowance for the wake effect of the tower and buildings and, where application, wind veer with altitude. The model equations express the conservation relationships for mometum, energy, total mass and water mass, for an incompressible fluid behaving in accordance with the Boussinesq assumptions. Condensation is represented by a simple thermodynamic model, and turbulent fluxes are simulated by introduction of turbulent viscosity and diffusivity data based on in-situ and experimental water model measurements. The three-dimensional problem expressed in terms of the primitive variables (u, v, w, p) is governed by an elliptic equation system which is solved numerically by application of an explicit time-marching algorithm in order to predict the steady-flow velocity distribution, temperature, water vapour concentration and the liquid-water concentration defining the visible plume. Windstill conditions are simulated by a program processing the elliptic equations in an axisymmetrical revolution coordinate system. The calculated visible plumes are compared with plumes observed on site with a view to validate the models [fr

  12. Thermal turbulent convection: thermal plumes and fluctuations

    International Nuclear Information System (INIS)

    Gibert, M.

    2007-10-01

    In this study we investigate the phenomenon of thermal turbulent convection in new and unprecedented ways. The first system we studied experimentally is an infinite vertical channel, where a constant vertical mean gradient of temperature exists. Inside this channel the average mass flux is null. The results obtained from our measurements reveal that the flow is mainly inertial; indeed the dissipative coefficients (here the viscosity) play a role only to define a coherence length L. This length is the distance over which the thermal plumes can be considered as 'free falling' objects. The horizontal transport, of heat and momentum, is entirely due to fluctuations. The associated 'mixing length' is small compared to the channel width. In the other hand, the vertical heat transport is due to coherent structures: the heat plumes. Those objects were also investigated in a Lagrangian study of the flow in the bulk of a Rayleigh-Benard cell. The probe, which has the same density as the fluid used in this experiment, is a sphere of 2 cm in diameter with embarked thermometers and radio-emitter. The heat plumes transport it, which allows a statistical study of such objects. (author)

  13. Monitoring and forecasting Etna volcanic plumes

    Directory of Open Access Journals (Sweden)

    S. Scollo

    2009-09-01

    Full Text Available In this paper we describe the results of a project ongoing at the Istituto Nazionale di Geofisica e Vulcanologia (INGV. The objective is to develop and implement a system for monitoring and forecasting volcanic plumes of Etna. Monitoring is based at present by multispectral infrared measurements from the Spin Enhanced Visible and Infrared Imager on board the Meteosat Second Generation geosynchronous satellite, visual and thermal cameras, and three radar disdrometers able to detect ash dispersal and fallout. Forecasting is performed by using automatic procedures for: i downloading weather forecast data from meteorological mesoscale models; ii running models of tephra dispersal, iii plotting hazard maps of volcanic ash dispersal and deposition for certain scenarios and, iv publishing the results on a web-site dedicated to the Italian Civil Protection. Simulations are based on eruptive scenarios obtained by analysing field data collected after the end of recent Etna eruptions. Forecasting is, hence, supported by plume observations carried out by the monitoring system. The system was tested on some explosive events occurred during 2006 and 2007 successfully. The potentiality use of monitoring and forecasting Etna volcanic plumes, in a way to prevent threats to aviation from volcanic ash, is finally discussed.

  14. Next-generation marine instruments to join plume debate

    Science.gov (United States)

    Simons, F. J.; Nolet, G.; Babcock, J.

    2003-12-01

    Whether hot spot volcanism is the consequence of plate tectonics or has a deep origin in a mantle plume is debated. G.~Foulger (Geol.~Soc.~London Lett.~Online, accessed 9/3/2003), writes that carefully truncated cross sections, with color scales cranked up, give noisy images the illusion of strong anomalies traversing the mantle. Don Anderson, the big daddy of non-plume hypotheses (R.~Kent, Geol.~Soc.~London Lett.~Online, accessed 9/3/2003) has written that the resolution of regional tomography experiments must be improved in order to successfully determine whether (...) the deep mantle is the controlling factor in the formation of proposed hot spots (Keller et al., GRL 27 (24), 2000). In particular for Iceland, at issue is the inherently limited aperture of any land-based seismometer array on the island: (...) the resolution of such images could be increased (...) by using ocean bottom seismometers (...) (ibidem). These problems are not unique to the plume debate. Coverage, resolution and robustness of models of the wave speed distribution in the interior of the Earth obtained by seismic tomographic inversions are limited by the areal distribution of seismic stations. Two thirds of Earth's surface are virtually inaccessible to passive-source seismometry, save indeed for expensive ocean-bottom seismometers or moored hydrophones. Elsewhere at this meeting, Montelli et al. describe how an improved theoretical treatment of the generation and survival of travel-time anomalies and sophisticated parameterization techniques yield unprecedented resolution of the seismic expression of a variety of ``plumes'' coming from all depths within the mantle. On the other hand, the improved resolution required to settling the debate on the depth to the seismic origin of various hot spots will also result from the collection of previously inaccessable data. Here, we show our progress in the development of an independent hydro-acoustical recording device mounted on SOLO floats. Our

  15. Evolution of a chemically reacting plume in a ventilated room

    Science.gov (United States)

    Conroy, D. T.; Smith, Stefan G. Llewellyn; Caulfield, C. P.

    2005-08-01

    The dynamics of a second-order chemical reaction in an enclosed space driven by the mixing produced by a turbulent buoyant plume are studied theoretically, numerically and experimentally. An isolated turbulent buoyant plume source is located in an enclosure with a single external opening. Both the source and the opening are located at the bottom of the enclosure. The enclosure is filled with a fluid of a given density with a fixed initial concentration of a chemical. The source supplies a constant volume flux of fluid of different density containing a different chemical of known and constant concentration. These two chemicals undergo a second-order non-reversible reaction, leading to the creation of a third product chemical. For simplicity, we restrict attention to the situation where the reaction process does not affect the density of the fluids involved. Because of the natural constraint of volume conservation, fluid from the enclosure is continually vented. We study the evolution of the various chemical species as they are advected by the developing ventilated filling box process within the room that is driven by the plume dynamics. In particular, we study both the mean and vertical distributions of the chemical species as a function of time within the room. We compare the results of analogue laboratory experiments with theoretical predictions derived from reduced numerical models, and find excellent agreement. Important parameters for the behaviour of the system are associated with the source volume flux and specific momentum flux relative to the source specific buoyancy flux, the ratio of the initial concentrations of the reacting chemical input in the plume and the reacting chemical in the enclosed space, the reaction rate of the chemicals and the aspect ratio of the room. Although the behaviour of the system depends on all these parameters in a non-trivial way, in general the concentration within the room of the chemical input at the isolated source passes

  16. The Prototype Plume Busters Software: A New Tool for Exploring Issues Related to Environmental Policy in Undergraduate-level Earth and Environmental Science Courses

    Science.gov (United States)

    Macfarlane, P. A.

    2006-12-01

    Students seldom have an opportunity to explore the issues related to the environmental impact of contamination on water resources. With NSF support we have developed the prototype Plume Busters, in which students take on the role of an environmental consultant. The software consists of an interactive, Java application and accompanying HTML linked pages. Following a pipeline spill, the environmental consultant is hired by the pipeline owner to locate the resulting plume created by the spill and remediate the contaminated aquifer at minimum monetary and time cost. The contamination must be removed from the aquifer before it reaches the river and eventually a downstream public water supply. The application simulates movement of a plume from a pipeline break through a shallow alluvial aquifer towards the river upstream from a municipal water supply intake. To locate the plume, the student places observation wells on a gridded map of the study area and the simulation returns the contaminant concentrations at those locations on the appropriate sample dates. Once the plume is located, the student is able to site pumping and injection wells on the map for aquifer remediation using a simple pump-and-treat technique. The simulation then computes the movement of particles to the pumping wells and returns the cumulative mass removed by the production remediation well. Plume Busters also provides teachers with a means to initiate student exploration of a wide range of environmental issues, including (1) source-water assessment and ground-water and wellhead protection zones, (2) the impact of human activities and technology on the hydrosphere and the biosphere, (3) the role of technology in the resolution of environmental issues (4) legal, social, political, and economic implications of environmental issues, and (5) risk assessment resulting from human activities.

  17. Recovery of transuranics from process residues

    International Nuclear Information System (INIS)

    Gray, J.H.; Gray, L.W.

    1987-01-01

    Process residues are generated at both the Rocky Flats Plant (RFP) and the Savannah River Plant (SRP) during aqueous chemical and pyrochemical operations. Frequently, process operations will result in either impure products or produce residues sufficiently contaminated with transuranics to be nondiscardable as waste. Purification and recovery flowsheets for process residues have been developed to generate solutions compatible with subsequent Purex operations and either solid or liquid waste suitable for disposal. The ''scrub alloy'' and the ''anode heel alloy'' are examples of materials generated at RFP which have been processed at SRP using the developed recovery flowsheets. Examples of process residues being generated at SRP for which flowsheets are under development include LECO crucibles and alpha-contaminated hydraulic oil

  18. Sustainable System for Residual Hazards Management

    International Nuclear Information System (INIS)

    Kevin M. Kostelnik; James H. Clarke; Jerry L. Harbour

    2004-01-01

    Hazardous, radioactive and other toxic substances have routinely been generated and subsequently disposed of in the shallow subsurface throughout the world. Many of today's waste management techniques do not eliminate the problem, but rather only concentrate or contain the hazardous contaminants. Residual hazards result from the presence of hazardous and/or contaminated material that remains on-site following active operations or the completion of remedial actions. Residual hazards pose continued risk to humans and the environment and represent a significant and chronic problem that require continuous long-term management (i.e. >1000 years). To protect human health and safeguard the natural environment, a sustainable system is required for the proper management of residual hazards. A sustainable system for the management of residual hazards will require the integration of engineered, institutional and land-use controls to isolate residual contaminants and thus minimize the associated hazards. Engineered controls are physical modifications to the natural setting and ecosystem, including the site, facility, and/or the residual materials themselves, in order to reduce or eliminate the potential for exposure to contaminants of concern (COCs). Institutional controls are processes, instruments, and mechanisms designed to influence human behavior and activity. System failure can involve hazardous material escaping from the confinement because of system degradation (i.e., chronic or acute degradation) or by external intrusion of the biosphere into the contaminated material because of the loss of institutional control. An ongoing analysis of contemporary and historic sites suggests that the significance of the loss of institutional controls is a critical pathway because decisions made during the operations/remedial action phase, as well as decisions made throughout the residual hazards management period, are key to the long-term success of the prescribed system. In fact

  19. Hydrogeologic analysis of remedial alternatives for the solar ponds plume, RFETS

    International Nuclear Information System (INIS)

    McLane, C.F. III; Whidden, J.A.; Hopkins, J.K.

    1998-01-01

    The focus of this paper is to develop a conceptual model and a hydrogeologic analysis plan for remedial alternatives being considered for the remediation of a ground water contaminant plume consisting of chiefly nitrate and uranium. The initial step in this process was to determine the adequacy of the existing data from the vast database of site information. Upon concluding that the existing database was sufficient to allow for the development of a conceptual model and then constructing the conceptual model, a hydrogeologic analysis plan was developed to evaluate several alternatives for plume remediation. The plan will be implemented using a combination of analytical and simple numerical ground water flow and contaminant transport models. This allows each portion of the study to be addressed using the appropriate tool, without having to develop a large three-dimensional numerical ground water flow and transport model, thereby reducing project costs. The analysis plan will consist of a preliminary phase of screening analyses for each of the remedial alternative scenarios, and a second phase of more comprehensive and in-depth analyses on a selected subset of remedial alternative scenarios. One of the alternatives which will be analyzed is phytoremediation (remediation of soil and ground water via uptake of chemicals by plants) because of the potential for relatively low capital and operation and maintenance costs, passive nature, and potential to provide long-term protection of the surface water. The results of these hydrogeological analyses will be factored into the selection of the preferred remedial alternative, or combination of alternatives, for the contaminant plume

  20. A generic model of contaminant migration from uranium tailings impoundments

    International Nuclear Information System (INIS)

    Shepherd, T.A.; Brown, S.E.

    1982-01-01

    This paper presents an analytical hydrogeochemical model based upon acid consumption-neutralization front movement. The development of contaminant plumes is discussed and distinct zones within these plumes are identified and characterized. The most important process influencing the rate and extent of contaminant migration at acid-leach uranium tailings impoundments is the neutralization of seepage water by soils along ground water flow paths. The chemical characteristics of the ground water is determined in order to identify and characterize zones within migrating plumes of tailings-derived water. It is concluded that the characterization of specific zones is useful in the interpretation of existing conditions, in the evaluation of future migration, and in the determination of appropriate models for the specific situation

  1. Predicted and observed cooling tower plume rise and visible plume length at the John E. Amos power plant

    Energy Technology Data Exchange (ETDEWEB)

    Hanna, S R

    1976-01-01

    A one-dimensional numerical cloud growth model and several empirical models for plume rise and cloud growth are compared with twenty-seven sets of observations of cooling tower plumes from the 2900 MW John E. Amos power plant in West Virginia. The three natural draft cooling towers are 200 m apart. In a cross wind, the plumes begin to merge at a distance of about 500 m downwind. In calm conditions, with reduced entrainment, the plumes often do not merge until heights of 1000 m. The average plume rise, 750 m, is predicted well by the models, but day-to-day variations are simulated with a correlation coefficient of about 0.5. Model predictions of visible plume length agree, on the average, with observations for visible plumes of short to moderate length (less than about 1 km). The prediction of longer plumes is hampered by our lack of knowledge of plume spreading after the plumes level off. Cloud water concentrations predicted by the numerical model agree with those measured in natural cumulus clouds (about 0.1 to 1 g kg/sup -1/).

  2. Waste Management Plan for the Drilling Within the Chromium Plume West of 100-D/DR Reactors

    International Nuclear Information System (INIS)

    R.E. Peterson

    1997-01-01

    This waste management plan provides guidance for managing drilling spoils generated during the installation of groundwater wells in the 100-D/DR Area, which is part of the 100-HR-3 Operable Unit. The wells are being installed to meet two objectives: (1) better define the nature and extent of a previously identified chromium plume in the area, and (2) act as groundwater extraction wells if the contamination warrants

  3. Lindane residues in fish inhabiting Nigerian rivers

    International Nuclear Information System (INIS)

    Okereke, G.U.; Dje, Y.

    1997-01-01

    Analysis for residues of lindane in fish collected from various rivers close to rice agroecosystems showed that the concentrations of lindane ranged from none detectable to 3.4 mg kg -1 . Fish from rivers where strict regulations prohibits its use had no detectable lindane residues while appreciable amounts of lindane were found in fish were such restriction was not enforced with the variation attributed to the extent of use of lindane in the area of contamination. The investigation confirms that the use of lindane in rice production in Nigeria can cause the contamination of fish in nearby rivers. (author). 16 refs, 2 tab

  4. Using tree core samples to monitor natural attenuation and plume distribution after a PCE spill

    DEFF Research Database (Denmark)

    Larsen, Morten; Burken, J.; Machackova, J.

    2008-01-01

    The potential of using tree core samples to detect and monitor natural attenuation of perchloroethene (PCE) in groundwater was investigated at a PCE-contaminated site. In the area of the known plume with PCE concentrations between 0.004 and >40 mg/L, cores were collected from tree trunks at a hei...... at a height of about 1 m above ground surface. Tree sampling of the site was completed in under six hours. Chlorinated ethenes were analyzed by headspace GC/MS. PCE (0.001 to 7 mg/kg) and natural attenuation products, TCE (...

  5. Plume Migration of Different Carbon Dioxide Phases During Geological Storage in Deep Saline Aquifers

    Directory of Open Access Journals (Sweden)

    Chien-Hao Shen

    2015-01-01

    Full Text Available This study estimates the plume migration of mobile supercritical phase (flowing, aqueous phase (dissolved, and ionic phase CO2 (bicarbonate, and evaluates the spatial distribution of immobile supercritical phase (residual and mineral phase CO2 (carbonates when CO2 was sequestered. This utilized a simulation, in an anticline structure of a deep saline aquifer in the Tiechenshan (TCS field, Taiwan. All of the trapping mechanisms and different CO2 phases were studied using the fully coupled geochemical equation-of-state GEM compositional simulator. The mobile supercritical phase CO2 moved upward and then accumulated in the up-dip of the structure because of buoyancy. A large amount of immobile supercritical phase CO2 was formed at the rear of the moving plume where the imbibition process prevailed. Both the aqueous and ionic phase CO2 finally accumulated in the down-dip of the structure because of convection. The plume volume of aqueous phase CO2 was larger than that of the supercritical phase CO2, because the convection process increased vertical sweep efficiency. The up-dip of the structure was not the major location for mineralization, which is different from mobile supercritical phase CO2 accumulation.

  6. Life Cycle of Mantle Plumes: A perspective from the Galapagos Plume (Invited)

    Science.gov (United States)

    Gazel, E.; Herzberg, C. T.

    2009-12-01

    Hotspots are localized sources of heat and magmatism considered as modern-day evidence of mantle plumes. Some hotspots are related to massive magmatic production that generated Large Igneous Provinces (LIPS), an initial-peak phase of plume activity with a mantle source hotter and more magmatically productive than present-day hotspots. Geological mapping and geochronological studies have shown much lower eruption rates for OIB compared to lavas from Large Igneous Provinces LIPS such as oceanic plateaus and continental flood provinces. Our study is the first quantitative petrological comparison of mantle source temperatures and extent of melting for OIB and LIP sources. The wide range of primary magma compositions and inferred mantle potential temperatures for each LIP and OIB occurrence suggest that this rocks originated form a hotspot, a spatially localized source of heat and magmatism restricted in time. Extensive outcrops of basalt, picrite, and sometimes komatiite with circa 65-95 Ma ages occupy portions of the pacific shore of Central and South America included in the Caribbean Large Igneous Province (CLIP). There is general consensus of a Pacific-origin of CLIP and most studies suggest that it was produced by melting in the Galapagos mantle plume. The Galapagos connection is consistent with isotopic and geochemical similarities with lavas from the present-day Galapagos hotspot. A Galapagos link for rocks in South American oceanic complexes (eg. the island of Gorgona) is more controversial and requires future work. The MgO and FeO contents of lavas from the Galapagos related lavas and their primary magmas have decreased since the Cretaceous. From petrological modeling we infer that these changes reflect a cooling of the Galapagos mantle plume from a potential temperature of 1560-1620 C in the Cretaceous to 1500 C at the present time. These temperatures are higher than 1350 C for ambient mantle associated with oceanic ridges, and provide support for the mantle

  7. [Perceived risks of food contaminants].

    Science.gov (United States)

    Koch, Severine; Lohmann, Mark; Epp, Astrid; Böl, Gaby-Fleur

    2017-07-01

    Food contaminants can pose a serious health threat. In order to carry out adequate risk communication measures, the subjective risk perception of the public must be taken into account. In this context, the breadth of the topic and insufficient terminological delimitations from residues and food additives make an elaborate explanation of the topic to consumers indispensable. A representative population survey used language adequate for lay people and a clear definition of contaminants to measure risk perceptions with regard to food contaminants among the general public. The study aimed to assess public awareness of contaminants and the perceived health risks associated with them. In addition, people's current knowledge and need for additional information, their attitudes towards contaminants, views on stakeholder accountability, as well as compliance with precautionary measures, such as avoiding certain foods to reduce health risks originating from contaminants, were assessed. A representative sample of 1001 respondents was surveyed about food contaminants via computer-assisted telephone interviewing. The majority of respondents rated contaminants as a serious health threat, though few of them spontaneously mentioned examples of undesirable substances in foods that fit the scientific or legal definition of contaminants. Mercury and dioxin were the most well-known contaminants. Only a minority of respondents was familiar with pyrrolizidine alkaloids. The present findings highlight areas that require additional attention and provide implications for risk communication geared to specific target groups.

  8. Helping Students make the transition from novice learner of ground-water concepts to expert using the Plume Busters software

    Science.gov (United States)

    Macfarlane, P.A.; Bohling, G.; Thompson, K.W.; Townsend, M.

    2006-01-01

    Environmental and earth science students are novice learners and lack the experience needed to rise to the level of expert. To address this problem we have developed the prototype Plume Busters?? software as a capstone educational experience, in which students take on the role of an environmental consultant. Following a pipeline spill, the environmental consultant is hired by the pipeline owner to locate the resulting plume created by spill and remediate the contaminated aquifer at minimum monetary and time cost. The contamination must be removed from the aquifer before it reaches the river and eventually a downstream public water supply. The software consists of an interactive Java application and accompanying HTML linked pages. The application simulates movement of a plume from a pipeline break throug h a shallow alluvial aquifer towards the river. The accompanying web pages establish the simulated contamination scenario and provide students with background material on ground-water flow and transport principles. To make the role-play more realistic, the student must consider cost and time when making decisions about siting observation wells and wells for the pump-and-treat remediation system.

  9. SRNL EMERGENCY RESPONSE CAPABILITY FOR ATMOSPHERIC CONTAMINANT RELEASES

    International Nuclear Information System (INIS)

    Koffman, L; Chuck Hunter, C; Robert Buckley, R; Robert Addis, R

    2006-01-01

    Emergency response to an atmospheric release of chemical or radiological contamination is enhanced when plume predictions, field measurements, and real-time weather information are integrated into a geospatial framework. The Weather Information and Display (WIND) System at Savannah River National Laboratory (SRNL) utilizes such an integrated framework. The rapid availability of predictions from a suite of atmospheric transport models within this geospatial framework has proven to be of great value to decision makers during an emergency involving an atmospheric contaminant release

  10. BACTERIA USED TO PRECIPITATE MERCURY IN CONTAMINATED GROUNDWATER OF PAVLODAR, KAZAKHSTAN

    Science.gov (United States)

    Abstract for poster presentation: A number of regions in Kazakhstan are contaminated with soluble mercury originating from industrial sources. A chlor-alkali plant that operated from 1970-1990 caused contamination of ground water near a northern suburb of Pavlodar city. The plume...

  11. An integral model of plume rise from high explosive detonations

    International Nuclear Information System (INIS)

    Boughton, B.A.; De Laurentis, J.M.

    1987-01-01

    A numerical model has been developed which provides a complete description of the time evolution of both the physical and thermodynamic properties of the cloud formed when a high explosive is detonated. This simulation employs the integral technique. The model equations are derived by integrating the three-dimensional conservation equations of mass, momentum and energy over the plume cross section. Assumptions are made regarding (a) plume symmetry; (b) the shape of profiles of velocity, temperature, etc. across the plume; and (c) the methodology for simulating entrainment and the effects of the crossflow induced pressure drag force on the plume. With these assumptions, the integral equations can be reduced to a set of ordinary differential equations on the plume centerline variables. Only the macroscopic plume characteristics, e.g., plume radius, centerline height, temperature and density, are predicted; details of the plume intrastructure are ignored. The model explicitly takes into account existing meteorology and has been expanded to consider the alterations in plume behavior which occur when aqueous foam is used as a dispersal mitigating material. The simulation was tested by comparison with field measurements of cloud top height and diameter. Predictions were within 25% of field observations over a wide range of explosive yield and atmospheric stability

  12. Studies of the environmental impact of evaporative cooling tower plumes

    International Nuclear Information System (INIS)

    Thomson, D.W.

    1978-01-01

    This ongoing research program of the environmental impact of natural-draft evaporative cooling tower plumes consists principally of a comprehensive series of airborne measurements of a variety of the physical characteristics of the plumes and, to a lesser extent, of preliminary studies of remote sodar plume probing techniques and the development of simplified dynamical numerical models suitable for use in conducting field measurement programs. The PSU Doppler sodar was used at the Keystone Power Plant in southwestern Pennsylvania for an extended series of remote measurements of the characteristics of plume turbulent temperature and velocity fluctuations and results are discussed

  13. Cooling tower plume - model and experiment

    Science.gov (United States)

    Cizek, Jan; Gemperle, Jiri; Strob, Miroslav; Nozicka, Jiri

    The paper discusses the description of the simple model of the, so-called, steam plume, which in many cases forms during the operation of the evaporative cooling systems of the power plants, or large technological units. The model is based on semi-empirical equations that describe the behaviour of a mixture of two gases in case of the free jet stream. In the conclusion of the paper, a simple experiment is presented through which the results of the designed model shall be validated in the subsequent period.

  14. Cooling tower plume - model and experiment

    Directory of Open Access Journals (Sweden)

    Cizek Jan

    2017-01-01

    Full Text Available The paper discusses the description of the simple model of the, so-called, steam plume, which in many cases forms during the operation of the evaporative cooling systems of the power plants, or large technological units. The model is based on semi-empirical equations that describe the behaviour of a mixture of two gases in case of the free jet stream. In the conclusion of the paper, a simple experiment is presented through which the results of the designed model shall be validated in the subsequent period.

  15. Anaerobic biodegradation of dissolved ethanol in a pilot-scale sand aquifer: Variability in plume (redox) biogeochemistry

    Science.gov (United States)

    McLeod, Heather C.; Roy, James W.; Slater, Gregory F.; Smith, James E.

    2018-01-01

    The use of ethanol in alternative fuels has led to contamination of groundwater with high concentrations of this easily biodegradable organic compound. Previous laboratory and field studies have shown vigorous biodegradation of ethanol plumes, with prevalence of reducing conditions and methanogenesis. The objective of this study was to further our understanding of the dynamic biogeochemistry processes, especially dissolved gas production, that may occur in developing and aging plume cores at sites with ethanol or other organic contamination of groundwater. The experiment performed involved highly-detailed spatial and temporal monitoring of ethanol biodegradation in a 2-dimensional (175 cm high × 525 cm long) sand aquifer tank for 330 days, with a vertical shift in plume position and increased nutrient inputs occurring at Day 100. Rapid onset of fermentation, denitrification, sulphate-reduction and iron(III)-reduction occurred following dissolved ethanol addition, with the eventual widespread development of methanogenesis. The detailed observations also demonstrate a redox zonation that supports the plume fringe concept, secondary reactions resulting from a changing/moving plume, and time lags for the various biodegradation processes. Additional highlights include: i) the highest dissolved H2 concentrations yet reported for groundwater, possibly linked to vigorous fermentation in the absence of common terminal electron-acceptors (i.e., dissolved oxygen, nitrate, and sulphate, and iron(III)-minerals) and methanogenesis; ii) evidence of phosphorus nutrient limitation, which stalled ethanol biodegradation and perhaps delayed the onset of methanogenesis; and iii) the occurrence of dissimilatory nitrate reduction to ammonium, which has not been reported for ethanol biodegradation to date.

  16. Chlorinated pesticide residues in sediments from the Arabian Sea along the Central West coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; SenGupta, R.

    Environmental contamination by persistent chlorinated pesticides has evoked major concern due to the presence of their residues in the environment. The quantitative distribution of chlorinated pesticides residues in the marine sediments from...

  17. Residues in food derived from animals

    International Nuclear Information System (INIS)

    Grossklaus, D.

    1989-01-01

    The first chapter presents a survey of fundamentals and methods of the detection and analysis of residues in food derived from animals, also referring to the resulting health hazards to man, and to the relevant legal provisions. The subsequent chapters have been written by experts of the Federal Health Office, each dealing with particular types of residues such as those of veterinary drugs, additives to animal feeds, pesticide residues, and with environmental pollutants and the contamination of animal products with radionuclides. (MG) With 35 figs., 61 tabs [de

  18. Rebound of a coal tar creosote plume following partial source zone treatment with permanganate.

    Science.gov (United States)

    Thomson, N R; Fraser, M J; Lamarche, C; Barker, J F; Forsey, S P

    2008-11-14

    The long-term management of dissolved plumes originating from a coal tar creosote source is a technical challenge. For some sites stabilization of the source may be the best practical solution to decrease the contaminant mass loading to the plume and associated off-site migration. At the bench-scale, the deposition of manganese oxides, a permanganate reaction byproduct, has been shown to cause pore plugging and the formation of a manganese oxide layer adjacent to the non-aqueous phase liquid creosote which reduces post-treatment mass transfer and hence mass loading from the source. The objective of this study was to investigate the potential of partial permanganate treatment to reduce the ability of a coal tar creosote source zone to generate a multi-component plume at the pilot-scale over both the short-term (weeks to months) and the long-term (years) at a site where there is >10 years of comprehensive synoptic plume baseline data available. A series of preliminary bench-scale experiments were conducted to support this pilot-scale investigation. The results from the bench-scale experiments indicated that if sufficient mass removal of the reactive compounds is achieved then the effective solubility, aqueous concentration and rate of mass removal of the more abundant non-reactive coal tar creosote compounds such as biphenyl and dibenzofuran can be increased. Manganese oxide formation and deposition caused an order-of-magnitude decrease in hydraulic conductivity. Approximately 125 kg of permanganate were delivered into the pilot-scale source zone over 35 days, and based on mass balance estimates 35% reduction for all monitored compounds except for biphenyl, dibenzofuran and fluoranthene 150 days after treatment, which is consistent with the bench-scale experimental results. Pre- and post-treatment soil core data indicated a highly variable and random spatial distribution of mass within the source zone and provided no insight into the mass removed of any of the

  19. Process related contaminations causing climatic reliability issues

    DEFF Research Database (Denmark)

    Jellesen, Morten Stendahl; Dutta, Mondira; Verdingovas, Vadimas

    2012-01-01

    contaminants during the wave and re-flow soldering process; however variation in temperature on the PCBA surface during soldering can result in considerable amounts of active residues being left locally. Typical no-clean flux systems used today consist of weak organic acids (WOA) and active residues left...

  20. Birth, life, and death of a solar coronal plume

    Energy Technology Data Exchange (ETDEWEB)

    Pucci, Stefano; Romoli, Marco [Department of Physics and Astronomy, University of Firenze, Largo Enrico Fermi 5, I-50125 Firenze (Italy); Poletto, Giannina [INAF-Arcetri Astrophysical Observatory, Largo Enrico Fermi 5, I-50125 Firenze (Italy); Sterling, Alphonse C., E-mail: stpucci@arcetri.astro.it [Space Science Office, NASA/MSFC, Huntsville, AL 35812 (United States)

    2014-10-01

    We analyze a solar polar-coronal-hole (CH) plume over its entire ≈40 hr lifetime, using high-resolution Solar Dynamic Observatory Atmospheric Imaging Assembly (AIA) data. We examine (1) the plume's relationship to a bright point (BP) that persists at its base, (2) plume outflows and their possible contribution to the solar wind mass supply, and (3) the physical properties of the plume. We find that the plume started ≈2 hr after the BP first appeared and became undetectable ≈1 hr after the BP disappeared. We detected radially moving radiance variations from both the plume and from interplume regions, corresponding to apparent outflow speeds ranging over ≈(30-300) km s{sup –1} with outflow velocities being higher in the 'cooler' AIA 171 Å channel than in the 'hotter' 193 Å and 211 Å channels, which is inconsistent with wave motions; therefore, we conclude that the observed radiance variations represent material outflows. If they persist into the heliosphere and plumes cover ≈10% of a typical CH area, these flows could account for ≈50% of the solar wind mass. From a differential emission measure analysis of the AIA images, we find that the average electron temperature of the plume remained approximately constant over its lifetime, at T {sub e} ≈ 8.5 × 10{sup 5} K. Its density, however, decreased with the age of the plume, being about a factor of three lower when the plume faded compared to when it was born. We conclude that the plume died due to a density reduction rather than to a temperature decrease.

  1. Deep structure of the Tristan-Gough plume revealed by geoid anomalies

    Science.gov (United States)

    Maia, M.; Flamme, J.; Cadio, C.; Lalancette, M. F.; Metivier, L.; Pajot-Métivier, G.; Diament, M.

    2017-12-01

    The origin of the hotspot Tristan da Cunha located at the southwestern end of Walvis Ridge in the Atlantic Ocean is still a controversial topic. We especially question on the nature of the involved geodynamical processes and on their origin depth. The latest results based on local seismic and magnetic data (Schlömer et al., 2016; Baba et al., 2016; Geissler et al., 2016) suggest the existence of a plume coming from the mid-mantle in the southwest of the archipelago. Here we give a regional view of mantle dynamics patterns in the area by using the high-quality satellite geoid data. To extract the mantle signature, we estimate the crustal and lithospheric signals of the ocean basin and South American and African continents, which contribute to mid- and long-wavelengths in the total geoid. We pay particular attention to the modeling of continental margins and their effects on the residual geoid signal. In addition, we explore a large density values set derived from petrological and geochemical studies in the calculation of the lithospheric geoid model. After subtracting the lithospheric signature to the EGM2008 geoid, we apply a multi-scale analysis, which unfolds the different components of the geoid residual signal. The analysis underlines a set of positive anomalies at 200-400 km in the study area, notably in north and west of Tristan de Cunha, and a positive anomaly at 700-1100 km scale in the southwest of the archipelago. These patterns do not change by using different lithospheric geoid models, which allow us to evaluate the reliability of the residual geoid anomalies. These results indicate the existence of small-scale density anomalies in the upper mantle and a larger scale density anomaly in the mid-mantle. Our study suggests that a large dome toped by plume clusters could be a good candidate to explain the volcanism of Tristan da Cunha.Schlömer et al., 2016 Hunting for the Tristan mantle plume..., EPSL, http://dx.doi.org/10.1016/j.epsl.2016.12.028Baba et

  2. Performance of monitoring networks estimated from a Gaussian plume model

    International Nuclear Information System (INIS)

    Seebregts, A.J.; Hienen, J.F.A.

    1990-10-01

    In support of the ECN study on monitoring strategies after nuclear accidents, the present report describes the analysis of the performance of a monitoring network in a square grid. This network is used to estimate the distribution of the deposition pattern after a release of radioactivity into the atmosphere. The analysis is based upon a single release, a constant wind direction and an atmospheric dispersion according to a simplified Gaussian plume model. A technique is introduced to estimate the parameters in this Gaussian model based upon measurements at specific monitoring locations and linear regression, although this model is intrinsically non-linear. With these estimated parameters and the Gaussian model the distribution of the contamination due to deposition can be estimated. To investigate the relation between the network and the accuracy of the estimates for the deposition, deposition data have been generated by the Gaussian model, including a measurement error by a Monte Carlo simulation and this procedure has been repeated for several grid sizes, dispersion conditions, number of measurements per location, and errors per single measurement. The present technique has also been applied for the mesh sizes of two networks in the Netherlands, viz. the Landelijk Meetnet Radioaciviteit (National Measurement Network on Radioactivity, mesh size approx. 35 km) and the proposed Landelijk Meetnet Nucleaire Incidenten (National Measurement Network on Nuclear Incidents, mesh size approx. 15 km). The results show accuracies of 11 and 7 percent, respectively, if monitoring locations are used more than 10 km away from the postulated accident site. These figures are based upon 3 measurements per location and a dispersion during neutral weather with a wind velocity of 4 m/s. For stable weather conditions and low wind velocities, i.e. a small plume, the calculated accuracies are at least a factor 1.5 worse.The present type of analysis makes a cost-benefit approach to the

  3. SRS reactor stack plume marking tests

    International Nuclear Information System (INIS)

    Petry, S.F.

    1992-03-01

    Tests performed in 105-K in 1987 and 1988 demonstrated that the stack plume can successfully be made visible (i.e., marked) by introducing smoke into the stack breech. The ultimate objective of these tests is to provide a means during an emergency evacuation so that an evacuee can readily identify the stack plume and evacuate in the opposite direction, thus minimizing the potential of severe radiation exposure. The EPA has also requested DOE to arrange for more tests to settle a technical question involving the correct calculation of stack downwash. New test canisters were received in 1988 designed to produce more smoke per unit time; however, these canisters have not been evaluated, because normal ventilation conditions have not been reestablished in K Area. Meanwhile, both the authorization and procedure to conduct the tests have expired. The tests can be performed during normal reactor operation. It is recommended that appropriate authorization and procedure approval be obtained to resume testing after K Area restart

  4. Channelization of plumes beneath ice shelves

    KAUST Repository

    Dallaston, M.  C.; Hewitt, I. J.; Wells, A. J.

    2015-01-01

    © 2015 Cambridge University Press. We study a simplified model of ice-ocean interaction beneath a floating ice shelf, and investigate the possibility for channels to form in the ice shelf base due to spatial variations in conditions at the grounding line. The model combines an extensional thin-film description of viscous ice flow in the shelf, with melting at its base driven by a turbulent ocean plume. Small transverse perturbations to the one-dimensional steady state are considered, driven either by ice thickness or subglacial discharge variations across the grounding line. Either forcing leads to the growth of channels downstream, with melting driven by locally enhanced ocean velocities, and thus heat transfer. Narrow channels are smoothed out due to turbulent mixing in the ocean plume, leading to a preferred wavelength for channel growth. In the absence of perturbations at the grounding line, linear stability analysis suggests that the one-dimensional state is stable to initial perturbations, chiefly due to the background ice advection.

  5. Channelization of plumes beneath ice shelves

    KAUST Repository

    Dallaston, M. C.

    2015-11-11

    © 2015 Cambridge University Press. We study a simplified model of ice-ocean interaction beneath a floating ice shelf, and investigate the possibility for channels to form in the ice shelf base due to spatial variations in conditions at the grounding line. The model combines an extensional thin-film description of viscous ice flow in the shelf, with melting at its base driven by a turbulent ocean plume. Small transverse perturbations to the one-dimensional steady state are considered, driven either by ice thickness or subglacial discharge variations across the grounding line. Either forcing leads to the growth of channels downstream, with melting driven by locally enhanced ocean velocities, and thus heat transfer. Narrow channels are smoothed out due to turbulent mixing in the ocean plume, leading to a preferred wavelength for channel growth. In the absence of perturbations at the grounding line, linear stability analysis suggests that the one-dimensional state is stable to initial perturbations, chiefly due to the background ice advection.

  6. Method of removing contaminants from plastic resins

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2008-11-18

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  7. Method for removing contaminants from plastic resin

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2008-12-30

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  8. Bioconversion of sago residue into value added products

    African Journals Online (AJOL)

    USER

    2010-04-05

    Apr 5, 2010 ... In Sarawak, East Malaysia, agro-residues from sago starch processing industries are ... conversion to animal food or fuel ethanol (Species. Profiles for Pacific Island ..... serious contamination of the rivers. Based on study by.

  9. Impacts of stormwater runoff in the Southern California Bight: Relationships among plume constituents

    Science.gov (United States)

    Reifel, K.M.; Johnson, S.C.; DiGiacomo, P.M.; Mengel, M.J.; Nezlin, N.P.; Warrick, J.A.; Jones, B.H.

    2009-01-01

    The effects from two winter rain storms on the coastal ocean of the Southern California Bight were examined as part of the Bight '03 program during February 2004 and February-March 2005. The impacts of stormwater from fecal indicator bacteria, water column toxicity, and nutrients were evaluated for five major river discharges: the Santa Clara River, Ballona Creek, the San Pedro Shelf (including the Los Angeles, San Gabriel, and Santa Ana Rivers), the San Diego River, and the Tijuana River. Exceedances of bacterial standards were observed in most of the systems. However, the areas of impact were generally spatially limited, and contaminant concentrations decreased below California Ocean Plan standards typically within 2-3 days. The largest bacterial concentrations occurred in the Tijuana River system where exceedances of fecal indicator bacteria were noted well away from the river mouth. Maximum nitrate concentrations (~40 ??M) occurred in the San Pedro Shelf region near the mouth of the Los Angeles River. Based on the results of general linear models, individual sources of stormwater differ in both nutrient concentrations and the concentration and composition of fecal indicator bacteria. While nutrients appeared to decrease in plume waters due to simple mixing and dilution, the concentration of fecal indicator bacteria in plumes depends on more than loading and dilution rates. The relationships between contaminants (nutrients and fecal indicator bacteria) and plume indicators (salinity and total suspended solids) were not strong indicating the presence of other potentially important sources and/or sinks of both nutrients and fecal indicator bacteria. California Ocean Plan standards were often exceeded in waters containing greater than 10% stormwater (variables can be used as proxies to provide at least a qualitative, if not quantitative, evaluation of the distribution of the dissolved, as well as the particulate, components of stormwater plumes. In this context

  10. Experimental Study Abour How the Thermal Plume Affects the Air Quality a Person Breathes

    DEFF Research Database (Denmark)

    Olmedo, Inés; Nielsen, Peter V.; Ruiz de Adana, Manuel

    2011-01-01

    of this research is to increase the knowledge of how the thermal plume generated by a person affects the PME and therefore the concentration of contaminants in the inhalation area. An experimental study in a displacement ventilation room was carried out. Experiments were developed in a full scale test chamber 4.......10 m (length), 3.2 m (width), 2.7 m (height). The incoming air is distributed through a wall-mounted displacement diffuser. A breathing thermal manikin exhaling through the mouth and inhaling through the nose was used. A tracer gas, N2O, was used to simulate the gaseous substances, which might...... be considered as biological contaminants, exhaled by the manikin. The manikin was operated in three different heat fluxes with a value of: 0W, 94 W and 120 W. During the experiments six concentration probes were situated in the room. Three concentration tubes were fixed on the surface of the manikin at three...

  11. Plume Splitting in a Two-layer Stratified Ambient Fluid

    Science.gov (United States)

    Ma, Yongxing; Flynn, Morris; Sutherland, Bruce

    2017-11-01

    A line-source plume descending into a two-layer stratified ambient fluid in a finite sized tank is studied experimentally. Although the total volume of ambient fluid is fixed, lower- and upper-layer fluids are respectively removed and added at a constant rate mimicking marine outfall through diffusers and natural and hybrid ventilated buildings. The influence of the plume on the ambient depends on the value of λ, defined as the ratio of the plume buoyancy to the buoyancy loss of the plume as it crosses the ambient interface. Similar to classical filling-box experiments, the plume can always reach the bottom of the tank if λ > 1 . By contrast, if λ < 1 , an intermediate layer eventually forms as a result of plume splitting. Eventually all of the plume fluid spreads within the intermediate layer. The starting time, tv, and the ending time, tt, of the transition process measured from experiments correlate with the value of λ. A three-layer ambient fluid is observed after transition, and the mean value of the measured densities of the intermediate layer fluid is well predicted using plume theory. Acknowledgments: Funding for this study was provided by NSERC.

  12. Morphology of the Zambezi River plume in the Sofala Bank ...

    African Journals Online (AJOL)

    In this paper, hydrographic data collected in the vicinity of the Zambezi River plume between 2004-2007 is discussed alongside historical data to infer the plume morphology. The sampling plan called for 73 CTD stations that were interspersed with sampling of shrimp recruitment. Satellite-derived wind speed and river ...

  13. Ocean outfall plume characterization using an Autonomous Underwater Vehicle.

    Science.gov (United States)

    Rogowski, Peter; Terrill, Eric; Otero, Mark; Hazard, Lisa; Middleton, William

    2013-01-01

    A monitoring mission to map and characterize the Point Loma Ocean Outfall (PLOO) wastewater plume using an Autonomous Underwater Vehicle (AUV) was performed on 3 March 2011. The mobility of an AUV provides a significant advantage in surveying discharge plumes over traditional cast-based methods, and when combined with optical and oceanographic sensors, provides a capability for both detecting plumes and assessing their mixing in the near and far-fields. Unique to this study is the measurement of Colored Dissolved Organic Matter (CDOM) in the discharge plume and its application for quantitative estimates of the plume's dilution. AUV mission planning methodologies for discharge plume sampling, plume characterization using onboard optical sensors, and comparison of observational data to model results are presented. The results suggest that even under variable oceanic conditions, properly planned missions for AUVs equipped with an optical CDOM sensor in addition to traditional oceanographic sensors, can accurately characterize and track ocean outfall plumes at higher resolutions than cast-based techniques.

  14. The mantle-plume model, its feasibility and consequences

    NARCIS (Netherlands)

    Calsteren, van P.W.C.

    1981-01-01

    High beat-flow foci on the Earth have been named ‘hot-spots’ and are commonly correlated with ‘mantle-plumes’ in the deep. A mantle plume may be described as a portion of mantle material with a higher heat content than its surroundings. The intrusion of a mantle-plume is inferred to be similar to

  15. Multiphase CFD modeling of nearfield fate of sediment plumes

    DEFF Research Database (Denmark)

    Saremi, Sina; Hjelmager Jensen, Jacob

    2014-01-01

    Disposal of dredged material and the overflow discharge during the dredging activities is a matter of concern due to the potential risks imposed by the plumes on surrounding marine environment. This gives rise to accurately prediction of the fate of the sediment plumes released in ambient waters...

  16. A study of space shuttle plumes in the lower thermosphere

    Science.gov (United States)

    Meier, R. R.; Stevens, Michael H.; Plane, John M. C.; Emmert, J. T.; Crowley, G.; Azeem, I.; Paxton, L. J.; Christensen, A. B.

    2011-12-01

    During the space shuttle main engine burn, some 350 t of water vapor are deposited at between 100 and 115 km. Subsequent photodissociation of water produces large plumes of atomic hydrogen that can expand rapidly and extend for thousands of kilometers. From 2002 to 2007, the Global Ultraviolet Imager (GUVI) on NASA's Thermosphere Ionosphere, Mesosphere, Energetics and Dynamics (TIMED) satellite imaged many of these hydrogen plumes at Lyman α (121.567 nm) while viewing in the nadir. The images reveal rapid plume expansion and occasional very fast transport to both north and south polar regions. Some plumes persist for up to 6 d. Near-simultaneous direct detections of water vapor were made with the Sounding of the Atmosphere with Broadband Emission Radiometry (SABER) instrument, also on TIMED. We compare the spreading of the hydrogen plume with a two-dimensional model that includes photodissociation as well as both vertical and horizontal diffusion. Molecular diffusion appears to be sufficient to account for the horizontal expansion, although wind shears and turbulent mixing may also contribute. We compare the bulk motion of the observed plumes with wind climatologies derived from satellite observations. The plumes can move much faster than predictions of wind climatologies. But dynamical processes not contained in wind climatologies, such as the quasi-two-day wave, can account for at least some of the high speed observations. The plume phenomena raise a number of important questions about lower thermospheric and mesospheric processes, ranging from dynamics and chemistry to polar mesospheric cloud formation and climatology.

  17. Chlorinated pesticide residues in marine sediments

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; SenGupta, R.

    of pesticide in contaminated river water into the Bay of Bengal. Con centration ranges of all these pesticide residues detected were, aldrine: 0.02-0.53, gamma BHC: 0.01-0.21, dieldrine: 0.05-0.51, and total DDT: 0.02-0.78, all in mu g g sup(-1) (wet wt)....

  18. Measures for radiation prevention and remediation of islightly radioactive contaminated sites by phytoremediation and subsequent utilization of the loaded plant residues (PHYTOREST). Final report; Massnahmen zur Strahlenschutzvorsorge radioaktiv belasteter Grossflaechen durch Sanierung mittels Phytoremediation und anschliessende Verwertung der belasteten Pflanzenreststoffe (PHYTOREST). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Willscher, Sabine; Werner, Peter [TU Dresden, Pirna (Germany). Inst. fuer Abfallwirtschaft und Altlasten; Jablonski, Lukasz; Wittig, Juliane

    2013-12-30

    contaminated geosubstrates now can be carried out within the radiation protection regulations. Hence, the project provides a substantial contribution to the radiation protection of HM/R contaminated soils. Within the research project, ways for the utilization of HM/R- contaminated plant residuals were highlighted; this gives a substantial contribution for minimization of wastes, the winning of sustainable bioenergy and the recycling of materials. Here, different ways of solutions were investigated. The research project was carried out within the scientific funding program ''Closedown and decommissioning of nuclear facilities''. The results of the project will contribute to the development of a biologically benign, sustainable technique for the remediation of large contaminated areas that originate mostly from the legacy of the former U mining. As a general result of this comprehensive research project, a phytostabilization/ phytoextraction of such SM/R contaminated sites is feasible with a protection of ground water, and the plant crop from phytoremediation of the HM/R contaminated field site can be utilized for the winning of bioenergy (gaseous/ liquid products or thermal utilization). The beneficial combination of phytoremediation and subsequent utilization of the biomass can be further developed to an innovative and sustainable remediation technology with national and international application potential.

  19. The role of alluvial aquifer sediments in attenuating a dissolved arsenic plume.

    Science.gov (United States)

    Ziegler, Brady A; Schreiber, Madeline E; Cozzarelli, Isabelle M

    2017-09-01

    In a crude-oil-contaminated sandy aquifer at the Bemidji site in northern Minnesota, biodegradation of petroleum hydrocarbons has resulted in release of naturally occurring As to groundwater under Fe-reducing conditions. This study used chemical extractions of aquifer sediments collected in 1993 and 2011-2014 to evaluate the relationship between Fe and As in different redox zones (oxic, methanogenic, Fe-reducing, anoxic-suboxic transition) of the contaminated aquifer over a twenty-year period. Results show that 1) the aquifer has the capacity to naturally attenuate the plume of dissolved As, primarily through sorption; 2) Fe and As are linearly correlated in sediment across all redox zones, and a regression analysis between Fe and As reasonably predicted As concentrations in sediment from 1993 using only Fe concentrations; 3) an As-rich "iron curtain," associated with the anoxic-suboxic transition zone, migrated 30m downgradient between 1993 and 2013 as a result of the hydrocarbon plume evolution; and 4) silt lenses in the aquifer preferentially sequester dissolved As, though As is remobilized into groundwater from sediment after reducing conditions are established. Using results of this study coupled with historical data, we develop a conceptual model which summarizes the natural attenuation of As and Fe over time and space that can be applied to other sites that experience As mobilization due to an influx of bioavailable organic matter. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. The role of alluvial aquifer sediments in attenuating a dissolved arsenic plume

    Science.gov (United States)

    Ziegler, Brady A.; Schreiber, Madeline E.; Cozzarelli, Isabelle M.

    2017-01-01

    In a crude-oil-contaminated sandy aquifer at the Bemidji site in northern Minnesota, biodegradation of petroleum hydrocarbons has resulted in release of naturally occurring As to groundwater under Fe-reducing conditions. This study used chemical extractions of aquifer sediments collected in 1993 and 2011–2014 to evaluate the relationship between Fe and As in different redox zones (oxic, methanogenic, Fe-reducing, anoxic-suboxic transition) of the contaminated aquifer over a twenty-year period. Results show that 1) the aquifer has the capacity to naturally attenuate the plume of dissolved As, primarily through sorption; 2) Fe and As are linearly correlated in sediment across all redox zones, and a regression analysis between Fe and As reasonably predicted As concentrations in sediment from 1993 using only Fe concentrations; 3) an As-rich “iron curtain,” associated with the anoxic-suboxic transition zone, migrated 30 m downgradient between 1993 and 2013 as a result of the hydrocarbon plume evolution; and 4) silt lenses in the aquifer preferentially sequester dissolved As, though As is remobilized into groundwater from sediment after reducing conditions are established. Using results of this study coupled with historical data, we develop a conceptual model which summarizes the natural attenuation of As and Fe over time and space that can be applied to other sites that experience As mobilization due to an influx of bioavailable organic matter.

  1. Hybrid cooling tower Neckarwestheim 2 cooling function, emission, plume dispersion

    International Nuclear Information System (INIS)

    Braeuning, G.; Ernst, G.; Maeule, R.; Necker, P.

    1990-01-01

    The fan-assisted hybrid cooling tower of the 1300 MW power plant Gemeinschafts-Kernkraftwerk Neckarwestheim 2 was designed and constructed based on results from theoretical and experimental studies and experiences from a smaller prototype. The wet part acts in counterflow. The dry part is arranged above the wet part. Each part contains 44 fans. Special attention was payed to the ducts which mix the dry into the wet plume. The cooling function and state, mass flow and contents of the emission were measured. The dispersion of the plume in the atmosphere was observed. The central results are presented in this paper. The cooling function corresponds to the predictions. The content of drifted cooling water in the plume is extremely low. The high velocity of the plume in the exit causes an undisturbed flow into the atmosphere. The hybrid operation reduces visible plumes strongly, especially in warmer and drier ambient air

  2. Análise da contaminação parasitária em compostos orgânicos produzidos com biossólidos de esgoto doméstico e resíduos agropecuários Analysis of parasitological contamination in organic composts with sewage sludge and agricultural residues

    Directory of Open Access Journals (Sweden)

    Eduardo Robson Duarte

    2008-08-01

    Full Text Available Este estudo avaliou a contaminação por ovos de helmintos, cistos e oocistos de protozoários em compostos orgânicos utilizando lodo de esgoto doméstico e resíduos agropecuários. Foram realizadas análises parasitológicas em amostras de 25 diferentes compostos orgânicos, antes e após tratamento térmico a 60°C durante 12 horas. Os resultados demonstraram elevada contaminação parasitária em todos os compostos analisados antes do tratamento e a não redução dessa contaminação após o tratamento térmico. A identificação das larvas obtidas em coproculturas antes e após o tratamento térmico dos compostos indicou que os gêneros mais freqüentemente observados foram Cooperia e Trichostrongylus, que são nematóides gastrintestinais de ruminantes. Estes resultados demonstram que ovos de helmintos podem permanecer viáveis mesmo após o processo de compostagem e o tratamento térmico. Os compostos produzidos com lodo de esgoto doméstico e resíduo agropecuários, utilizando esses processos de tratamentos, podem constituir riscos de contaminação para humanos e animais.This research aimed at evaluating the cysts, oocysts and eggs contamination before and after thermal treatment of 60°C for 12 hours, in 25 different organic composts produced with biosolids from domestic waste-water treatment and animal and agricultural residues. The results showed high parasitological contamination for all organic composts before the treatment and these contaminations were not reduced after thermic treatment. The larva identification in coprocultures before and after thermic treatment showed Cooperia spp. and Trichostrongylus spp. were the most prevalent nematodes. These results demonstrated that helmintus’ eggs can remain viable even after the composing and thermic treatment. The obtained composition with sewage sludge and agricultural residues through these treatment processes can establish contamination risks for humans and animals.

  3. Light contamination

    International Nuclear Information System (INIS)

    Cepeda Pena, William Enrique

    1998-01-01

    The article tries on the wrong use of the artificial light, of the main problems of the light contamination, dispersion of the light, noxious effects of the light contamination, ecological effects, effects on the man's biological rhythm, economic effects and effects about the civic and vial security, among other topics

  4. Sinking, merging and stationary plumes in a coupled chemotaxis-fluid model: a high-resolution numerical approach

    KAUST Repository

    Chertock, A.; Fellner, K.; Kurganov, A.; Lorz, A.; Markowich, P. A.

    2012-01-01

    examples, which illustrate (i) the formation of sinking plumes, (ii) the possible merging of neighbouring plumes and (iii) the convergence towards numerically stable stationary plumes. The examples with stable stationary plumes show how the surface

  5. Vadose Zone Contaminant Fate and Transport Analysis for the 216-B-26 Trench

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Andy L.; Gee, Glendon W.; Zhang, Z. F.; Keller, Jason M.

    2004-10-14

    contaminant inventory and water content depth distributions of any complexity. However, the results are somewhat conservative in that the model does not take credit for stratification and its dimensionality effects. Transient analysis shows transport to be controlled by small-scale stratification that resulted in laterally movement of contaminants and their failure to reach the ground water. Multiple discharges quickly merged into a single plume that migrated beyond the domain boundaries. However, it appears that this very feature that was effective in mitigating deep transport of the contaminants for almost 50 years now functions to confound expected barrier effects. Simulations suggest that a barrier provides no additional protection above the no-action alternative. Although continuous layers are assumed, in reality, there may be discontinuities that could lead to vertical movement. Episodic recharge events could also be conducive to downward movement. As more data becomes available, the conceptual model will be revised. Based on the analyses, capping appears to be no better than the no-action alternative. Projected 99Tc concentrations reaching the groundwater suggest that alternate source control actions may be necessary to reach soil screening levels. The benefits of active remediation are therefore readily apparent. Because none of the alternatives reduce soil concentrations, they effect no active reduction in the groundwater concentrations therefore the residual risk will remain high.

  6. Evapotranspiration And Geochemical Controls On Groundwater Plumes At Arid Sites: Toward Innovative Alternate End-States For Uranium Processing And Tailings Facilities

    International Nuclear Information System (INIS)

    Looney, Brian B.; Denham, Miles E.; Eddy-Dilek, Carol A.; Millings, Margaret R.; Kautsky, Mark

    2014-01-01

    Management of legacy tailings/waste and groundwater contamination are ongoing at the former uranium milling site in Tuba City AZ. The tailings have been consolidated and effectively isolated using an engineered cover system. For the existing groundwater plume, a system of recovery wells extracts contaminated groundwater for treatment using an advanced distillation process. The ten years of pump and treat (P and T) operations have had minimal impact on the contaminant plume - primarily due to geochemical and hydrological limits. A flow net analysis demonstrates that groundwater contamination beneath the former processing site flows in the uppermost portion of the aquifer and exits the groundwater as the plume transits into and beneath a lower terrace in the landscape. The evaluation indicates that contaminated water will not reach Moenkopi Wash, a locally important stream. Instead, shallow groundwater in arid settings such as Tuba City is transferred into the vadose zone and atmosphere via evaporation, transpiration and diffuse seepage. The dissolved constituents are projected to precipitate and accumulate as minerals such as calcite and gypsum in the deep vadose zone (near the capillary fringe), around the roots of phreatophyte plants, and near seeps. The natural hydrologic and geochemical controls common in arid environments such as Tuba City work together to limit the size of the groundwater plume, to naturally attenuate and detoxify groundwater contaminants, and to reduce risks to humans, livestock and the environment. The technical evaluation supports an alternative beneficial reuse (''brownfield'') scenario for Tuba City. This alternative approach would have low risks, similar to the current P and T scenario, but would eliminate the energy and expense associated with the active treatment and convert the former uranium processing site into a resource for future employment of local citizens and ongoing benefit to the Native American Nations

  7. Evapotranspiration And Geochemical Controls On Groundwater Plumes At Arid Sites: Toward Innovative Alternate End-States For Uranium Processing And Tailings Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Looney, Brian B.; Denham, Miles E.; Eddy-Dilek, Carol A.; Millings, Margaret R.; Kautsky, Mark

    2014-01-08

    Management of legacy tailings/waste and groundwater contamination are ongoing at the former uranium milling site in Tuba City AZ. The tailings have been consolidated and effectively isolated using an engineered cover system. For the existing groundwater plume, a system of recovery wells extracts contaminated groundwater for treatment using an advanced distillation process. The ten years of pump and treat (P&T) operations have had minimal impact on the contaminant plume – primarily due to geochemical and hydrological limits. A flow net analysis demonstrates that groundwater contamination beneath the former processing site flows in the uppermost portion of the aquifer and exits the groundwater as the plume transits into and beneath a lower terrace in the landscape. The evaluation indicates that contaminated water will not reach Moenkopi Wash, a locally important stream. Instead, shallow groundwater in arid settings such as Tuba City is transferred into the vadose zone and atmosphere via evaporation, transpiration and diffuse seepage. The dissolved constituents are projected to precipitate and accumulate as minerals such as calcite and gypsum in the deep vadose zone (near the capillary fringe), around the roots of phreatophyte plants, and near seeps. The natural hydrologic and geochemical controls common in arid environments such as Tuba City work together to limit the size of the groundwater plume, to naturally attenuate and detoxify groundwater contaminants, and to reduce risks to humans, livestock and the environment. The technical evaluation supports an alternative beneficial reuse (“brownfield”) scenario for Tuba City. This alternative approach would have low risks, similar to the current P&T scenario, but would eliminate the energy and expense associated with the active treatment and convert the former uranium processing site into a resource for future employment of local citizens and ongoing benefit to the Native American Nations.

  8. Towards LES Models of Jets and Plumes

    Science.gov (United States)

    Webb, A. T.; Mansour, N. N.

    2000-01-01

    As pointed out by Rodi standard integral solutions for jets and plumes developed for discharge into infinite, quiescent ambient are difficult to extend to complex situations, particularly in the presence of boundaries such as the sea floor or ocean surface. In such cases the assumption of similarity breaks down and it is impossible to find a suitable entrainment coefficient. The models are also incapable of describing any but the most slowly varying unsteady motions. There is therefore a need for full time-dependent modeling of the flow field for which there are three main approaches: (1) Reynolds averaged numerical simulation (RANS), (2) large eddy simulation (LES), and (3) direct numerical simulation (DNS). Rodi applied RANS modeling to both jets and plumes with considerable success, the test being a match with experimental data for time-averaged velocity and temperature profiles as well as turbulent kinetic energy and rms axial turbulent velocity fluctuations. This model still relies on empirical constants, some eleven in the case of the buoyant jet, and so would not be applicable to a partly laminar plume, may have limited use in the presence of boundaries, and would also be unsuitable if one is after details of the unsteady component of the flow (the turbulent eddies). At the other end of the scale DNS modeling includes all motions down to the viscous scales. Boersma et al. have built such a model for the non-buoyant case which also compares well with measured data for mean and turbulent velocity components. The model demonstrates its versatility by application to a laminar flow case. As its name implies, DNS directly models the Navier-Stokes equations without recourse to subgrid modeling so for flows with a broad spectrum of motions (high Re) the cost can be prohibitive - the number of required grid points scaling with Re(exp 9/4) and the number of time steps with Re(exp 3/4). The middle road is provided by LES whereby the Navier-Stokes equations are formally

  9. Modelling thermal plume impacts - Kalpakkam approach

    International Nuclear Information System (INIS)

    Rao, T.S.; Anup Kumar, B.; Narasimhan, S.V.

    2002-01-01

    A good understanding of temperature patterns in the receiving waters is essential to know the heat dissipation from thermal plumes originating from coastal power plants. The seasonal temperature profiles of the Kalpakkam coast near Madras Atomic Power Station (MAPS) thermal out fall site are determined and analysed. It is observed that the seasonal current reversal in the near shore zone is one of the major mechanisms for the transport of effluents away from the point of mixing. To further refine our understanding of the mixing and dilution processes, it is necessary to numerically simulate the coastal ocean processes by parameterising the key factors concerned. In this paper, we outline the experimental approach to achieve this objective. (author)

  10. Fine particles in the Soufriere eruption plume

    Science.gov (United States)

    Woods, D. C.; Chuan, R. L.

    1982-01-01

    The size distributions of fine particles measured at tropospheric altitudes in the periphery of the eruption plume formed during the April 17, 1979 eruption of Soufriere Volcano and in the low-level effluents on May 15, 1979 were found to be bimodal, having peak concentrations at geometric mean diameters of 1.1 and 0.23 micrometers. Scanning electron microscopy and energy-dispersive X-ray analysis of the samples revealed an abundance of aluminum and silicon and traces of sodium, magnesium, chlorine, potassium, calcium, and iron in the large-particle mode. The submicrometer-sized particles were covered with liquid containing sulfur, assumed to be in the form of liquid sulfuric acid.

  11. Infrared Imagery of Solid Rocket Exhaust Plumes

    Science.gov (United States)

    Moran, Robert P.; Houston, Janice D.

    2011-01-01

    The Ares I Scale Model Acoustic Test program consisted of a series of 18 solid rocket motor static firings, simulating the liftoff conditions of the Ares I five-segment Reusable Solid Rocket Motor Vehicle. Primary test objectives included acquiring acoustic and pressure data which will be used to validate analytical models for the prediction of Ares 1 liftoff acoustics and ignition overpressure environments. The test article consisted of a 5% scale Ares I vehicle and launch tower mounted on the Mobile Launch Pad. The testing also incorporated several Water Sound Suppression Systems. Infrared imagery was employed during the solid rocket testing to support the validation or improvement of analytical models, and identify corollaries between rocket plume size or shape and the accompanying measured level of noise suppression obtained by water sound suppression systems.

  12. Is the 'Fast Halo' around Hawaii as imaged in the PLUME experiment direct evidence for buoyant plume-fed asthenosphere?

    Science.gov (United States)

    Morgan, J. P.; Shi, C.; Hasenclever, J.

    2010-12-01

    An intriguing spatial pattern of variations in shear-wave arrival times has been mapped in the PLUME ocean bottom experiment (Wolfe et al., 2009) around Hawaii. The pattern consists of a halo of fast travel times surrounding a disk of slow arrivals from waves traveling up though the plume. We think it is directly sensing the pattern of dynamic uplift of the base of a buoyant asthenosphere - the buoyancy of the plume conduit lifting a 'rim' of the cooler, denser mantle that the plume rises through. The PLUME analysis inverted for lateral shear velocity variations beneath the lithosphere, after removing the assumed 1-D model velocity structure IASP91. They found that a slow plume-conduit extends to at least 1200 km below the Hawaiian hotspot. In this inversion the slow plume conduit is — quite surprisingly - surrounded by a fast wavespeed halo. A fast halo is impossible to explain as a thermal halo around the plume; this should lead to a slow wavespeed halo, not a fast one. Plume-related shearwave anisotropy also cannot simply explain this pattern — simple vertical strain around the plume conduit would result in an anisotropic slow shear-wavespeed halo, not a fast one. (Note the PLUME experiment’s uniform ‘fast-halo’ structure from 50-400km is likely to have strong vertical streaking in the seismic image; Pacific Plate-driven shear across a low-viscosity asthenosphere would be expected to disrupt and distort any cold sheet of vertical downwelling structure between 50-400km depths so that it would no longer be vertical as it is in the 2009 PLUME image with its extremely poor vertical depth control.) If the asthenosphere is plume-fed, hence more buoyant than underlying mantle, then there can be a simple explanation for this pattern. The anomaly would be due to faster traveltimes resulting from dynamic relief at the asthenosphere-mesosphere interface; uplift of the denser mesosphere by the buoyancy of the rising plume increases the distance a wave travels

  13. Detecting Volcanic Ash Plumes with GNSS Signals

    Science.gov (United States)

    Rainville, N.; Larson, K. M.; Palo, S. E.; Mattia, M.; Rossi, M.; Coltelli, M.; Roesler, C.; Fee, D.

    2016-12-01

    Global Navigation Satellite Systems (GNSS) receivers are commonly placed near volcanic sites to measure ground deformation. In addition to the carrier phase data used to measure ground position, these receivers also record Signal to Noise ratio (SNR) data. Larson (2013) showed that attenuations in SNR data strongly correlate with ash emissions at a series of eruptions of Redoubt Volcano. This finding has been confirmed at eruptions for Tongariro, Mt Etna, Mt Shindake, and Sakurajima. In each of these detections, very expensive geodetic quality GNSS receivers were used. If low-cost GNSS instruments could be used instead, a networked array could be deployed and optimized for plume detection and tomography. The outputs of this sensor array could then be used by both local volcanic observatories and Volcano Ash Advisory Centers. Here we will describe progress in developing such an array. The sensors we are working with are intended for navigation use, and thus lack the supporting power and communications equipment necessary for a networked system. Reliably providing those features is major challenge for the overall sensor design. We have built prototypes of our Volcano Ash Plume Receiver (VAPR), with solar panels, lithium-ion batteries and onboard data storage for preliminary testing. We will present results of our field tests of both receivers and antennas. A second critical need for our array is a reliable detection algorithm. We have tested our algorithm on data from recent eruptions and have incorporated the noise characteristics of the low-cost GNSS receiver. We have also developed a simulation capability so that the receivers can be deployed to optimize vent crossing GNSS signals.

  14. Statistical analysis of ground-water contamination at the alert apron and northern landfill areas of Wurtsmith AFB, Michigan. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, P.; Naber, S.; Verducci, J.

    1988-07-01

    Two plumes of contamination are analyzed to determine their extent, composition, and movement. The large number of ground-water monitoring wells sampled over the past eight years at Wurtsmith AFB allow this analysis to be performed directly from empirical data, with minimal assumptions about solute transport mechanisms. Conclusions are drawn about the likely sources of contamination in the two plumes, the adequacy of the data for making risk assessments, and the likely consequences of alternative programs of remediation.

  15. Interpreting residues of petroleum hydrocarbons in wildlife tissues

    International Nuclear Information System (INIS)

    Hall, R.J.; Coon, N.C.

    1988-08-01

    This report is the first publication in the field of environmental-contaminant effects on wildlife to tell the reader how to interpret the results of analytical chemical results. Specifically, the publication describes how to interpret residues of petroleum hydrocarbons in wildlife tissues. Pollutant oil residues in avian species are emphasized

  16. Quantification of Plume-Soil Interaction and Excavation Due to the Sky Crane Descent Stage

    Science.gov (United States)

    Vizcaino, Jeffrey; Mehta, Manish

    2015-01-01

    The quantification of the particulate erosion that occurs as a result of a rocket exhaust plume impinging on soil during extraterrestrial landings is critical for future robotic and human lander mission design. The aerodynamic environment that results from the reflected plumes results in dust lifting, site alteration and saltation, all of which create a potentially erosive and contaminant heavy environment for the lander vehicle and any surrounding structures. The Mars Science Lab (MSL), weighing nearly one metric ton, required higher levels of thrust from its retro propulsive systems and an entirely new descent system to minimize these effects. In this work we seek to quantify plume soil interaction and its resultant soil erosion caused by the MSL's Sky Crane descent stage engines by performing three dimensional digital terrain and elevation mapping of the Curiosity rover's landing site. Analysis of plume soil interaction altitude and time was performed by detailed examination of the Mars Descent Imager (MARDI) still frames and reconstructed inertial measurement unit (IMU) sensor data. Results show initial plume soil interaction from the Sky Crane's eight engines began at ground elevations greater than 60 meters and more than 25 seconds before the rovers' touchdown event. During this time, viscous shear erosion (VSE) was dominant typically resulting in dusting of the surface with flow propagating nearly parallel to the surface. As the vehicle descended and decreased to four powered engines plume-plume and plume soil interaction increased the overall erosion rate at the surface. Visibility was greatly reduced at a height of roughly 20 meters above the surface and fell to zero ground visibility shortly after. The deployment phase of the Sky Crane descent stage hovering at nearly six meters above the surface showed the greatest amount of erosion with several large particles of soil being kicked up, recirculated, and impacting the bottom of the rover chassis. Image

  17. Dispersion, deposition and resuspension of atmospheric contaminants

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    The following topics are discussed: dry deposition, oil shale fugitive air emissions, particle resuspension and translocation, theoretical studies and applications, and processing of emissions by clouds and precipitation. The concentration of contaminant species in air is governed by the rate of input from sources, the rate of dilution or dispersion as a result of air turbulence, and the rate of removal to the surface by wet and dry deposition processes. Once on the surface, contaminants also may be resuspended, depending on meteorological and surface conditions. An understanding of these processes is necessary for accurate prediction of exposures of hazardous or harmful contaminants to humans, animals, and crops. In the field, plume dispersion and plume depletion by dry deposition were studied by the use of tracers. Dry deposition was investigated for particles of both respiration and inhalation interest. Complementary dry deposition studies of particles to rock canopies were conducted under controlled conditions in a wind tunnel. Because of increasing concern about hazardous, organic gases in the atmosphere some limited investigations of the dry deposition of nitrobenzene to a lichen mat were conducted in a stirred chamber. Resuspension was also studied using tracers and contaminated surfaces and in the wind tunnel. The objective of the resuspension studies was to develop and verify models for predicting the airborne concentrations of contaminants over areas with surface contamination, develop resuspension rate predictors for downwind transport, and develop predictors for resuspension input to the food chain. These models will be of particular relevance to the evaluation of deposition and resuspension of both radionuclides and chemical contaminants

  18. Geophysical Signitures From Hydrocarbon Contaminated Aquifers

    Science.gov (United States)

    Abbas, M.; Jardani, A.

    2015-12-01

    The task of delineating the contamination plumes as well as studying their impact on the soil and groundwater biogeochemical properties is needed to support the remediation efforts and plans. Geophysical methods including electrical resistivity tomography (ERT), induced polarization (IP), ground penetrating radar (GPR), and self-potential (SP) have been previously used to characterize contaminant plumes and investigate their impact on soil and groundwater properties (Atekwana et al., 2002, 2004; Benson et al., 1997; Campbell et al., 1996; Cassidy et al., 2001; Revil et al., 2003; Werkema et al., 2000). Our objective was to: estimate the hydrocarbon contamination extent in a contaminated site in northern France, and to adverse the effects of the oil spill on the groundwater properties. We aim to find a good combination of non-intrusive and low cost methods which we can use to follow the bio-remediation process, which is planned to proceed next year. We used four geophysical methods including electrical resistivity tomography, IP, GPR, and SP. The geophysical data was compared to geochemical ones obtained from 30 boreholes installed in the site during the geophysical surveys. Our results have shown: low electrical resistivity values; high chargeability values; negative SP anomalies; and attenuated GPR reflections coincident with groundwater contamination. Laboratory and field geochemical measurements have demonstrated increased groundwater electrical conductivity and increased microbial activity associated with hydrocarbon contamination of groundwater. Our study results support the conductive model suggested by studies such as Sauck (2000) and Atekwana et al., (2004), who suggest that biological alterations of hydrocarbon contamination can substantially modify the chemical and physical properties of the subsurface, producing a dramatic shift in the geo-electrical signature from resistive to conductive. The next stage of the research will include time lapse borehole

  19. Cone penetrometer testing (CPT) for groundwater contamination

    International Nuclear Information System (INIS)

    Jordan, J.E.; Van Pelt, R.S.

    1993-01-01

    Over the past decade, researchers at the Savannah River Site (SRS) and elsewhere have greatly advanced the knowledge of waste site characterization technologies. As a result, many of the techniques used in the past to investigate waste sites have been replaced by newer technologies, designed to provide greater protection for human health and the environment, greater access to suspected zones of contamination, and more accurate information of subsurface conditions. Determining the most environmentally sound method of assessing a waste unit is a major component of the SRS environmental restoration program. In an effort to understand the distribution and migration of contaminants in the groundwater system, the cone penetrometer investigation of the A/M-Area Southern Sector was implemented. The program incorporated a phased approach toward characterization by first using the CPT to delineate the plume boundary, followed by installing groundwater monitoring wells. The study provided the additional hydrogeologic information necessary to better understand the nature and extent of the contaminant plume (Fig. 1) and the hydrogeologic system in the Southem Sector. This data is essential for the optimal layout of the planned groundwater monitoring well network and recovery system to remediate the aquifers in the area. A number of other test locations were selected in the area during this study for lithologic calibration of the tool and to collect confirmation water samples from the aquifer. Cone penetrometer testing and hydrocone sampling, were performed at 17 sites (Fig. 2). The hydrocone, a tool modification to the CPT, was used to collect four groundwater samples from confined aquifers. These samples were analyzed by SRS laboratories. Elevated levels of chlorinated compounds were detected from these samples and have aided in further delineating the southern sector contaminant plume

  20. Microbiology, Redox and Contaminat Fate in the Grindsted Landfill Leachate Plume - A Summary of 25 Years of work

    Science.gov (United States)

    Christensen, T. H.

    2001-05-01

    The contamination by leachate of the upper aquifer at the Grindsted Landfill (Denmark) stretches about 300 m downgradient from the landfill. The plume has been described with respect to water chemistry, sediment chemistry, pollutant distribution, microbial counts, PLFA and redox rates determined by unamended bioassays. This presentation summaries the findings and discusses unanswered questions. The landfill was active from 1930 to the mid 1970 and has no engineered leachate collection system. Leachate from municipal as well as from industrial waste has entered the aquifer for more than thirty years. The redox conditions change from strongly anaerobic (methanogenic, sulfate reducing, iron reducing) close to the landfill over manganese reduction and denitrification to aerobic conditions in the outskirts of the plume The redox conditions were determined from groundwater sample composition, hydrogen concentrations and sediment chemistry. The plume showed strong attenuation of aromatic compounds within the first 100 m downgradient of the landfill. Degradation experiments (batch, in-situ testers, long term field injection experiments) could not fully document degradation of all the compounds. MPN-measurements of methanogens, sulfate-reducers, iron-reducers, manganese-reducers and denitrifiers showed abundance of all groups with a slight trend with the redox conditions. PLFA measurements did not provide much insight into the microbial populations of the plume, but confirmed some previous observations. Bioassays gave estimates of the rates of the various redox processes, but showed for some samples more simultaneous redox processes. More than 25 years of work has been put into the Grindsted Landfill leachate plume. References Bjerg, P.L., Rugge, K., Cortsen, J., Nielsen, P.H. & Christensen, T.H. (1999): Degradation of aromatic and chlorinated aliphatic hydrocarbons in the anaerobic part of the Grindsted Landfill leachate plume: In situ microcosm and laboratory batch

  1. NW Iberia Shelf Dynamics. Study of the Douro River Plume.

    Directory of Open Access Journals (Sweden)

    Isabel Iglesias

    2014-06-01

    Full Text Available River plumes are one of the most important mechanisms that transport the terrestrial materials to the coast and the ocean. Some examples of those materials are pollutants, essential nutrients, which enhance the phytoplankton productivity or sediments, which settle on the seabed producing modifications on the bathymetry affecting the navigation channels. The mixing between the riverine and the oceanic waters can induce instabilities, which might generate bulges, filaments, and buoyant currents over the continental shelf. Offshore, the buoyant riverine water could form a front with the oceanic waters often related with the occurrence of current-jets, eddies and strong mixing. The study and modelling of the river plumes is a key factor for the complete understanding of sediment transport mechanisms and patterns, and of coastal physics and dynamic processes. On this study the Douro River plume will be simulated. The Douro River is located on the north-west Iberian coast and its daily averaged freshwater discharge can range values from 0 to 13000 m3/s. This variability impacts the formation of the river plumes and its dispersion along the continental shelf. This study builds on the long-term objective of generate a Douro River plume forecasting system as part of the RAIA and RAIA.co projects. Satellite imagery was analyzed showing that the river Douro is one of the main sources of suspended particles, dissolved material and chlorophyll in the NW Iberian Shelf. The Regional Oceanic Modeling System (ROMS model was selected to reproduce scenarios of plume generation, retention and dispersion. Whit this model, three types of simulations were performed: (i schematic winds simulations with prescribed river flow, wind speed and direction; (ii multi-year climatological simulation, with river flow and temperature change for each month; (iii extreme case simulation, based on the Entre-os-Rios accident situation. The schematic wind case-studies suggest that the

  2. Satellite Remote Sensing Detection of Coastal Pollution in Southern California: Stormwater Runoff and Wastewater Plumes

    Science.gov (United States)

    Trinh, R. C.; Holt, B.; Gierach, M.

    2016-02-01

    Coastal pollution poses a major health and environmental hazard, not only for beach goers and coastal communities but for marine organisms as well. Stormwater runoff is the largest source of environmental pollution in coastal waters of the Southern California Bight (SCB) and is of great concern in increasingly urbanized areas. Buoyant wastewater plumes also pose a marine environmental risk. In this study we provide a comprehensive overview of satellite remote sensing capabilities in detecting buoyant coastal pollutants in the form of stormwater runoff and wastewater effluent. The SCB is the final destination of four major urban rivers that act as channels for runoff and pollution during and after rainstorms. We analyzed and compared sea surface roughness data from various Synthetic Aperture Radar (SAR) instruments to ocean color data from the Moderate Imaging System (MODIS) sensor on board the Aqua satellite and correlated the results with existing environmental data in order to create a climatology of naturally occurring stormwater plumes in coastal waters after rain events, from 1992 to 2014 from four major rivers in the area. Heat maps of the primary extent of stormwater plumes were constructed to specify areas that may be subject to the greatest risk of coastal contamination. In conjunction with our efforts to monitor coastal pollution and validate the abilities of satellite remote sensing, a recent Fall 2015 wastewater diversion from the City of Los Angeles Hyperion Treatment Plant (HTP) provided the opportunity to apply these remote sensing methodologies of plume detection to wastewater. During maintenance of their 5-mile long outfall pipe, wastewate