WorldWideScience

Sample records for surface contamination zone

  1. TECHNICAL BASIS FOR EVALUATING SURFACE BARRIERS TO PROTECT GROUNDWATER FROM DEEP VADOSE ZONE CONTAMINATION

    International Nuclear Information System (INIS)

    Fayer, J.M.; Freedman, V.L.; Ward, A.L.; Chronister, G.B.

    2010-01-01

    The U.S. DOE and its predecessors released nearly 2 trillion liters (450 billion gallons) of contaminated liquid into the vadose zone at the Hanford Site. Some of the contaminants currently reside in the deeper parts of the vadose zone where they are much less accessible to characterization, monitoring, and typical remediation activities. The DOE Richland Operations Office (DOE-RL) prepared a treatability test plan in 2008 to examine remediation options for addressing contaminants in the deep vadose zone; one of the technologies identified was surface barriers (also known as engineered barriers, covers, and caps). In the typical configuration, the contaminants are located relatively close to the surface, generally within 15 m, and thus they are close to the base of the surface barrier. The proximity of the surface barrier under these conditions yielded few concerns about the effectiveness of the barrier at depth, particularly for cases in which the contaminants were in a lined facility. At Hanford, however, some unlined sites have contaminants located well below depths of 15 m. The issue raised about these sites is the degree of effectiveness of a surface barrier in isolating contaminants in the deep vadose zone. Previous studies by Hanford Site and PNNL researchers suggest that surface barriers have the potential to provide a significant degree of isolation of deep vadose zone contaminants. The studies show that the actual degree of isolation is site-specific and depends on many factors, including recharge rates, barrier size, depth of contaminants, geohydrologic properties ofthe sediments, and the geochemical interactions between the contaminants and the sediments. After the DOE-RL treatability test plan was published, Pacific Northwest National Laboratory was contracted to review the information available to support surface barrier evaluation for the deep vadose zone, identify gaps in the information and outcomes necessary to fill the data gaps, and outline

  2. Heavy metal contamination in surface sediments of Yangtze River intertidal zone: An assessment from different indexes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Weiguo [State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062 (China); Feng Huan, E-mail: fengh@mail.montclair.ed [Department of Earth and Environmental Studies, Montclair State University, 1 Normal Avenue, Montclair, NJ 07043 (United States); Chang Jinna; Qu Jianguo; Xie Hongxia; Yu Lizhong [State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062 (China)

    2009-05-15

    Surface sediments (0-5 cm) from 59 stations within the Yangtze River intertidal zone (YRIZ) were sampled for metal contamination analysis in April and August 2005. The concentrations ranged (in mg kg{sup -1} dry weight): Al, 40,803-97,213; Fe, 20,538-49,627; Cd, 0.12-0.75; Cr, 36.9-173; Cu, 6.87-49.7; Mn, 413-1,112; Ni, 17.6-48.0; Pb, 18.3-44.1; and Zn, 47.6-154; respectively. Among the 59 sampling stations, enrichment factors (EF) indicate enrichment of Cd (52 stations), Cr (54 stations), Cu (5 stations), Ni (26 stations), Pb (5 stations) and Zn (5 stations). Geoaccumulation indexes (I{sub geo}) also suggest individual metal contamination in localized areas. This study indicates that Cd, Cr and Ni enrichment in the YRIZ sediment is widespread whereas Cu, Mn, Pb and Zn enrichment is localized or nonexistent. Factor and cluster analyses indicate that Cd is associated with total organic carbon whereas Cu, Cr, Ni, Pb and Zn have a close association with Mn. - Surface sediment metal enrichment is evidenced for Cd, Cr and Ni in the Yangtze River intertidal zone.

  3. Surface tritium contamination studies

    International Nuclear Information System (INIS)

    Sienkiewicz, C.J.

    1986-01-01

    Glovebox wipe surveys were conducted to correlate surface tritium contamination with atmospheric tritium levels. Surface contamination was examined as a function of tritium concentration and limited to the HT/T 2 form. The previously predicted relationship between atmospheric HTO concentration and cleanup times was examined in order to predict a model for atmospheric detritiation of stainless steel enclosures. 2 figures, 2 tables

  4. Assessment of hyporheic zone, flood-plain, soil-gas, soil, and surface-water contamination at the Old Incinerator Area, Fort Gordon, Georgia, 2009-2010

    Science.gov (United States)

    Guimaraes, Wladmir B.; Falls, W. Fred; Caldwell, Andral W.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2011-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, Georgia, assessed the hyporheic zone, flood plain, soil gas, soil, and surface-water for contaminants at the Old Incinerator Area at Fort Gordon, from October 2009 to September 2010. The assessment included the detection of organic contaminants in the hyporheic zone, flood plain, soil gas, and surface water. In addition, the organic contaminant assessment included the analysis of explosives and chemical agents in selected areas. Inorganic contaminants were assessed in soil and surface-water samples. The assessment was conducted to provide environmental contamination data to the U.S. Army at Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. Total petroleum hydrocarbons were detected above the method detection level in all 13 samplers deployed in the hyporheic zone and flood plain of an unnamed tributary to Spirit Creek. The combined concentrations of benzene, toluene, ethylbenzene, and total xylene were detected at 3 of the 13 samplers. Other organic compounds detected in one sampler included octane and trichloroethylene. In the passive soil-gas survey, 28 of the 60 samplers detected total petroleum hydrocarbons above the method detection level. Additionally, 11 of the 60 samplers detected the combined masses of benzene, toluene, ethylbenzene, and total xylene above the method detection level. Other compounds detected above the method detection level in the passive soil-gas survey included octane, trimethylbenzene, perchlorethylene, and chloroform. Subsequent to the passive soil-gas survey, six areas determined to have relatively high contaminant mass were selected, and soil-gas samplers were deployed, collected, and analyzed for explosives and chemical agents. No explosives or chemical agents were detected above

  5. Geochemical and isotopic evidences from groundwater and surface water for understanding of natural contamination in chronic kidney disease of unknown etiology (CKDu) endemic zones in Sri Lanka.

    Science.gov (United States)

    Edirisinghe, E A N V; Manthrithilake, H; Pitawala, H M T G A; Dharmagunawardhane, H A; Wijayawardane, R L

    2017-09-26

    Chronic kidney disease of unknown etiology (CKDu) is the main health issue in the dry zone of Sri Lanka. Despite many studies carried out, causative factors have not been identified yet clearly. According to the multidisciplinary researches carried out so far, potable water is considered as the main causative factor for CKDu. Hence, the present study was carried out with combined isotopic and chemical methods to understand possible relationships between groundwater; the main drinking water source, and CKDu in four endemic areas in the dry zone. Different water sources were evaluated isotopically ( 2 H, 3 H and 18 O) and chemically from 2013 to 2015. Results revealed that prevalence of CKDu is significantly low with the groundwater replenished by surface water inputs. It is significantly high with the groundwater stagnated as well as groundwater recharged from regional flow paths. Thus, the origin, recharge mechanism and flow pattern of groundwater, as well as geological conditions which would be responsible for natural contamination of groundwater appear as the main causative factors for CKDu. Therefore, detailed investigations should be made in order to identify the element(s) in groundwater contributing to CKDu. The study recommends providing drinking water to the affected zones using water sources associated with surface waters.

  6. Contaminant mass estimation of powder contaminated surfaces

    Science.gov (United States)

    Gibbs, Timothy J.; Messinger, David W.

    2017-05-01

    How can we determine the physical characteristics of a mixture of multiple materials within a single pixel? Intimate mixing occurs when different materials within the region encompassed by a pixel interact with each other prior to reaching the sensor. For powder contaminated surfaces, nonlinear mixing is unavoidable. The Nonconventional Exploitation Factors Data System (NEFDS) Contamination Model can make longwave hyperspectral mixture signatures, but only for a small subset of their spectral library. In addition, the model uses percent coverage as its only physical property input despite it not being informative to the contaminants physical properties. Through a complex parameter inversion, the NEFDS contamination model can be used to derive various physical properties. These physical characteristics were estimated by using empirically measured data of varying contaminant amounts using a Designs and Prototypes Fourier transform infrared spectrometer. Once estimated parameters are found, the mixture spectra was recreated and compared to the measured data. The estimated areal coverage density is used to derive a total deposited mass on the surface based on the area of contaminated surface. This is compared to the known amount deposited that was measured during the experimental campaign. This paper presents some results of those measurements and model estimates.

  7. Instruments Sniff Organic Surface Contaminants

    Science.gov (United States)

    Adler-Golden, Steven; Matthew, Michael W.

    1995-01-01

    Portable instruments detecting both nonvolatile and volatile organic surface contaminants in real time developed. Instruments easy to use: operate under ordinary ambient atmospheric conditions, without need to use messy liquid solvents or install and remove witness plates, and without need to cut specimens from surfaces to be inspected. Principle of detection involves sweeping pure, activated gas across surface spot inspected, then monitoring light emitted at wavelengths characteristic of excited molecules formed by chemical reactions between activated gas and contaminants. Gas activated by dc discharge, radio-frequency induction, microwave radiation, laser beam, hot filaments, or any other suitable means that excites some of gas molecules.

  8. Derived limits for surface contamination

    CERN Document Server

    Wrixon, A D; Linsley, G S; White, D F

    1979-01-01

    Derived limits (DLs) for surface contamination were first established for use in the nuclear energy industry where a wide variety of radionuclides is encountered. They were later used in factories, hospitals, and universities, where the radionuclides used are normally fewer in number, either known or readily identifiable, and often of low toxicity. In these situations the current limits are frequently over-restrictive. This report describes a reassessment of the values in the light of more recent information on the possible pathways of exposure and the dose equivalent limits given in ICRP Publication 26. The reassessment is prompted also by the introduction of SI units. The results of the reassessment are used to produce a classification of DLs for all radionuclides for active and inactive area surfaces and for skin.

  9. Transport and degradation of contaminants in the vadose zone

    NARCIS (Netherlands)

    Schotanus, D.

    2013-01-01

    Leaching of contaminants from the vadose zone to the groundwater depends on the soil properties and the infiltration rate. In this thesis, organic degradable contaminants were studied, such as de-icing chemicals (consisting of propylene glycol, PG) and pesticides. Heterogeneous soil properties

  10. Assessment of Hyporheic Zone, Flood-Plain, Soil-Gas, Soil, and Surface-Water Contamination at the McCoys Creek Chemical Training Area, Fort Gordon, Georgia, 2009-2010

    Science.gov (United States)

    Guimaraes, Wladmir B.; Falls, W. Fred; Caldwell, Andral W.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2011-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, Georgia, assessed the hyporheic zone, flood plain, soil gas, soil, and surface water for contaminants at the McCoys Creek Chemical Training Area (MCTA) at Fort Gordon, from October 2009 to September 2010. The assessment included the detection of organic contaminants in the hyporheic zone, flood plain, soil gas, and surface water. In addition, the organic contaminant assessment included the analysis of organic compounds classified as explosives and chemical agents in selected areas. Inorganic contaminants were assessed in soil and surface-water samples. The assessment was conducted to provide environmental contamination data to the U.S. Army at Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. Ten passive samplers were deployed in the hyporheic zone and flood plain, and total petroleum hydrocarbons (TPH) and octane were detected above the method detection level in every sampler. Other organic compounds detected above the method detection level in the hyporheic zone and flood-plain samplers were trichloroethylene, and cis- and trans- 1, 2-dichloroethylene. One trip blank detected TPH below the method detection level but above the nondetection level. The concentrations of TPH in the samplers were many times greater than the concentrations detected in the blank; therefore, all other TPH concentrations detected are considered to represent environmental conditions. Seventy-one soil-gas samplers were deployed in a grid pattern across the MCTA. Three trip blanks and three method blanks were used and not deployed, and TPH was detected above the method detection level in two trip blanks and one method blank. Detection of TPH was observed at all 71 samplers, but because TPH was detected in the trip and method blanks, TPH was

  11. Evaluation of Unfixed Tritium Surface Contamination

    International Nuclear Information System (INIS)

    Postolache, C.; Matei, Lidia

    2005-01-01

    Surface unfixed radioactive contamination represents the amount of surface total radioactive contamination which can be eliminated by pure mechanical processes. This unfixed contamination represents the main risk factor for contamination of the personnel which operates in tritium laboratories. Unfixed contamination was determined using sampling smears type FPCSN-PSE-AA. Those FPCSN-PSE-AA smears are disks of expanded polystyrene which contain acrylic acid fragments superficially grafted. Sampling factor was determinated by contaminated surface wiping with moisten smears in 50 μL butylic alcohol and activity measuring at liquid scintillation measuring device. Sampling factor was determined by the ratio between measured activity and initially real conventional activity. The sampling factor was determined for Tritium Laboratory existent surfaces: stainless steel, aluminum, glass, ceramics, linoleum, washable coats, epoxy resins type ALOREX LP-52.The sampling factors and the reproducibility were determined in function of surface nature

  12. Techniques for removing contaminated concrete surfaces

    International Nuclear Information System (INIS)

    Halter, J.M.; Sullivan, R.G.

    1981-01-01

    This discussion compares various techniques that have been used to clean concrete surfaces by removing the surface. Three techniques which have been investigated by the Pacific Northwest Laboratory for removing surfaces are also described: the water cannon, the concrete spaller, and high-pressure water jet. The equipment was developed with the assumption that removal of the top 1/8 to 1/4 in. of surface would remove most of the contamination. If the contamination has gone into cracks or deep voids in the surface, the removal processes can be repeated until the surface is acceptable

  13. Characterization of the vadose zone above a shallow aquifer contaminated with gas condensate hydrocarbons

    International Nuclear Information System (INIS)

    Sublette, K.; Duncan, K.; Thoma, G.; Todd, T.

    2002-01-01

    A gas production site in the Denver Basin near Ft. Lupton, Colorado has leaked gas condensate hydrocarbons from an underground concrete tank used to store produced water. The leak has contaminated a shallow aquifer. Although the source of pollution has been removed, a plume of hydrocarbon contamination still remains for nearly 46 m from the original source. An extensive monitoring program was conducted in 1993 of the groundwater and saturated sediments. The objective was to determine if intrinsic aerobic or anaerobic bioremediation of hydrocarbons occurred at the site at a rate that would support remediation. Geochemical indicators of hydrogen biodegradation by microorganisms in the saturated zone included oxygen depletion, increased alkalinity, sulfate depletion, methane production and Fe2+ production associated with hydrogen contamination. The presence of sulfate-reducing bacteria and methanogens was also much higher in the contaminated sediments. Degraded hydrocarbon metabolites were found in contaminated groundwater. An extensive characterization of the vadose zone was conducted in which the vadose zone was sample in increments of 15 cm from the surface to the water table at contaminated and non contaminated sites. The samples were tested for individual C3+ hydrocarbons, methane, CO2, total organic carbon, total inorganic carbon, and total petroleum hydrocarbons. The vadose zone consisted of an active and aerobic bioreactor fueled by condensate hydrocarbons transported into the unsaturated zone by evaporation of hydrocarbons at the water table. It was concluded that the unsaturated zone makes an important contribution to the natural attenuation of gas condensate hydrocarbons in the area. 17 refs., 2 tabs., 28 figs

  14. Evaluating Transport and Attenuation of Inorganic Contaminants in the Vadose Zone for Aqueous Waste Disposal Sites

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tartakovsky, Guzel D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-01

    An approach was developed for evaluating vadose zone transport and attenuation of aqueous wastes containing inorganic (non-volatile) contaminants that were disposed of at the land surface (i.e., directly to the ground in cribs, trenches, tile fields, etc.) and their effect on the underlying groundwater. The approach provides a structured method for estimating transport of contaminants through the vadose zone and the resulting temporal profile of groundwater contaminant concentrations. The intent of the approach is also to provide a means for presenting and explaining the results of the transport analysis in the context of the site-specific waste disposal conditions and site properties, including heterogeneities and other complexities. The document includes considerations related to identifying appropriate monitoring to verify the estimated contaminant transport and associated predictions of groundwater contaminant concentrations. While primarily intended for evaluating contaminant transport under natural attenuation conditions, the approach can also be applied to identify types of, and targets for, mitigation approaches in the vadose zone that would reduce the temporal profile of contaminant concentrations in groundwater, if needed.

  15. Calibration of alpha surface contamination monitor

    International Nuclear Information System (INIS)

    Freitas, I.S.M. de; Goncalez, O.L.

    1990-01-01

    In this work, the results, as well as the methodology, of the calibration of an alpha surface contamination monitor are presented. The calibration factors are obtained by least-squares fitting with effective variance. (author)

  16. ModBack - simplified contaminant source zone delineation using backtracking

    Science.gov (United States)

    Thielsch, K.; Herold, M.; Ptak, T.

    2012-12-01

    Contaminated groundwater poses a serious threat to drinking water resources all over the world. Even though contaminated water might be detected in observation wells, a proper clean up is often only successful if the source of the contamination is detected and subsequently removed, contained or remediated. The high costs of groundwater remediation could be possibly significantly reduced if, from the outset, a focus is placed on source zone detection. ModBack combines several existing modelling tools in one easy to use GIS-based interface helping to delineate potential contaminant source zones in the subsurface. The software is written in Visual Basic 3.5 and uses the ArcObjects library to implement all required GIS applications. It can run without modification on any Microsoft Windows based PC with sufficient RAM and at least Microsoft .NET Framework 3.5. Using ModBack requires additional installation of the following software: Processing Modflow Pro 7.0, ModPath, CSTREAM (Bayer-Raich et al., 2003), Golden Software Surfer and Microsoft Excel. The graphical user interface of ModBack is separated into four blocks of procedures dealing with: data input, groundwater modelling, backtracking and analyses. Geographical data input includes all georeferenced information pertaining to the study site. Information on subsurface contamination is gathered either by conventional sampling of monitoring wells or by conducting integral pumping tests at control planes with a specific sampling scheme. Hydraulic data from these pumping tests together with all other available information are then used to set up a groundwater flow model of the study site, which provides the flow field for transport simulations within the subsequent contamination backtracking procedures, starting from the defined control planes. The backtracking results are then analysed within ModBack. The potential areas of contamination source presence or absence are determined based on the procedure used by Jarsjö et

  17. Monitoring of surface and airborne contamination

    Energy Technology Data Exchange (ETDEWEB)

    Pradeep Kumar, K.S. [Bhabha Atomic Research Centre, Bombay (India)

    1997-06-01

    Indian nuclear energy programme aims at total safety in all activities involved in the entire fuel cycle for the occupational workers, members of the public and the environment as a whole. Routine radiation monitoring with clearly laid out procedures are followed for ensuring the safety of workers and public. Radiation monitoring carried out for the nuclear installations comprises of process monitoring, monitoring of effluent releases and also of the radiation protection monitoring of the individuals, work place and environment. Regulations like banning of smoking and consumption of food and drink etc. reduces the risk of direct ingestion even if inadvertent spread of contamination takes place. Though limit of transportable surface contamination is prescribed, the health physicists always follow a ``clean on swipe`` philosophy which compensates any error in the measurement of surface contamination. In this paper, the following items are contained: Necessity of contamination monitoring, accuracy required in the calibration of surface contamination monitors, methodology for contamination monitoring, air monitoring, guidelines for unrestricted release of scrap materials, and problems in contamination monitoring. (G.K.)

  18. Development of radioactive surface contamination monitor

    International Nuclear Information System (INIS)

    Hashimoto, Tadao; Hasegawa, Toru; Fukumoto, Keisuke; Ooki, Yasushi

    2008-01-01

    In the radiation facilities such as nuclear power plants, surface contamination of the people accessing or articles conveyed in and out of the radiation controlled areas is detected and monitored by installing contamination monitors at the boundary of controlled areas and uncontrolled areas against the expansion of the radioactive materials to out of the facilities. It is required for the surface contamination of articles to be tightened of control criteria as 'Guidelines for discrimination ways of nonradioactive waste (not classified as radioactive waste) generated from nuclear power plants' (hereinafter referred to as 'the Guideline') was established by the Nuclear and Industrial Safety Agency of the Ministry of Economy, Trade and Industry in August, 2005. It predicts that the control criteria of monitors other than article monitors are also tightened in the future. Fuji electric has been fabricating and delivering surface contamination detecting monitors. Now we are developing the new contamination monitor corresponding to the tightening of the control criteria. 'Large article transfer monitor', 'Clothing monitor' and 'Body surface contamination monitor' are introduced in this article. (author)

  19. Uranium Concentration of Contaminated Zone due to the Cover Depth for Self-Disposal

    International Nuclear Information System (INIS)

    Koo, Dae Seo; Sung, Hyun Hee; Kim, Gye Nam; Kim, Seung Soo; Kim, Il Gook; Han, Gyu Seong; Choi, Jong Won

    2016-01-01

    To acquire radiation dose under self disposal from them, the study on decontamination of some uranium contaminated soil and concrete wastes was performed using electrokinetic-electrodialytic. In this study, we evaluated radiation dose due to cover depth on contaminated zone such as uranium contaminated soil and concrete wastes under radiation dose limit using RESRAD Version 6.5. At first, the calculation of the radiation dose on the contaminated zone are carried out. The second, the uranium concentration of contaminated zone due to the cover depth are also analyzed. The uranium contaminated soil and concrete wastes under radiation dose limit by decontaminating them have application to self-disposal of contaminated zone. The area of contaminated zone is 1,500 m 2 . The thickness of contaminated zone is 2 m. The length parallel to aquifer flow is 43.702m. The age of the residents on contaminated zone is 15 years old. The period of evaluation on the contaminated zone is from regulation exemption of uranium contaminated soil and concrete wastes till 1,000 years. The calculation of the radiation dose on contaminated zone are carried out. The uranium concentration of contaminated zone due to the cover depth was also analyzed. as the cover depth increases, the uranium concentration has an increasing trend. As the cover depth increases, radiation dose of a person has a decreasing trend. As the cover depth increases, the radiation dose of residents has also a decreasing trend.

  20. Radionuclide contaminated micromycetes in the soil the thirty kilometer zone

    International Nuclear Information System (INIS)

    Zhdanova, N.N.; Vasilevskaya, A.I.; Redchits, T.I.; Gavrilov, V.I.; Lashko, T.N.; Luchkov, P.N.; Shcherbachenko, A.M.; AN Ukrainskoj SSR, Kiev

    1992-01-01

    From 1986 year the ecological monitoring of the soil microscopic fungi exist under conditions of the radioactive contamination in the thirty kilometer zone of the Chernobyl' NPP is conducted. As mycological isotope soil analysis the limiting factor in the ecological situation need consider the radionuclide contamination of the soils. It is shown, that the amount of fungus germs decreased by 200 times in 1986 year and increased sharp to 1989-90 years. During the first years after the accident, in the most contaminated soils dark-pigmented fungi predominated. It is due to a deep reorganization of the soil micromycete associations. Correlations is revealed in the interrelations among various species of fungi, isolated from the soils, differed in the radioactivity. Among 12 species of fungi (from 6 genuses of micromycetes) isotope accumulation is noted. There are Sr-90 and Cs-137, most widespread in the soil after the accident. 18 refs.; 8 figs

  1. Summary of Vadose -- Zone Conceptual Models for Flow and Contaminant Transport and 1999 - 2003 Progress on Resolving Deficiencies in Understanding the Vadose Zone at the INEEL

    Energy Technology Data Exchange (ETDEWEB)

    Robert C. Starr; Dana L. Dettmers; Brennon R. Orr; Thomas R. Wood

    2003-12-01

    The thick vadose zone that underlies the Idaho National Engineering and Environmental Laboratory has been recognized both as an avenue through which contaminants disposed at or near the ground surface can migrate to groundwater in the underlying Eastern Snake River Plain aquifer, and as a barrier to the movement of contaminants into the aquifer. Flow and contaminant transport in the vadose zone at the INEEL is complicated by the highly heterogeneous nature of the geologic framework and by the variations in the behavior of different contaminants in the subsurface. The state of knowledge concerning flow and contaminant transport in the vadose zone at and near the INEEL IN 1999 was summarized in Deficiencies in Vadose Zone Understanding at the Idaho National Engineering and Environmental Laboratory (Wood et al., 2000). These authors identified deficiencies in knowledge of flow and contaminant transport processes in the vadose zone, and provided recommendations for additional work that should be conducted to address these deficiencies. In the period since (Wood et al., 2000) was prepared, research has been published that, to some degree, address these deficiencies. This document provides a bibliography of reports, journal articles, and conference proceedings published 1999 through mid-2003 that are relevant to the vadose zone at or near the INEEL and provides a brief description of each work. Publications that address specific deficiencies or recommendations are identified, and pertinent information from selected publications is presented.

  2. Occurrence of Surface Water Contaminations: An Overview

    Science.gov (United States)

    Shahabudin, M. M.; Musa, S.

    2018-04-01

    Water is a part of our life and needed by all organisms. As time goes by, the needs by human increased transforming water quality into bad conditions. Surface water contaminated in various ways which is pointed sources and non-pointed sources. Pointed sources means the source are distinguished from the source such from drains or factory but the non-pointed always occurred in mixed of elements of pollutants. This paper is reviewing the occurrence of the contaminations with effects that occurred around us. Pollutant factors from natural or anthropology factors such nutrients, pathogens, and chemical elements contributed to contaminations. Most of the effects from contaminated surface water contributed to the public health effects also to the environments.

  3. Quantification of surface contamination: principles and applications

    International Nuclear Information System (INIS)

    Vo-Dinh, T.

    1982-01-01

    The applications discussed in this paper underscore the usefulness and versatility of molecular luminescence spectroscopy as an efficient surface detection technique. The technique can be used not only as a qualitative characterization method, but also as a quantitative analytical tool to detect trace contaminants on surfaces. Recent advances in instrumentation and methodology have expanded the applicability of surface luminescence into many new problem areas. Trace organics are emphasized here

  4. Modelling of contamination of surface atmosphere for deflation of Cesium-137 on contaminated territories

    International Nuclear Information System (INIS)

    Bogdanov, A.P.; Zhmura, G.M.

    1994-01-01

    Presence of Cesium 137 in near land air is caused at the contaminated territories by 'local' dusting and transport of the dust from the zone of strong contamination. For large distance is it caused by resuspension of radioactive dust from the surface in the given region. In accordance with the models of dusting round square sources based on Gauss statistical model of dissemination of admixtures in the atmosphere, the contaminated areas of european part of the former of USSR with the density of contamination over 1 Ci/km 2 with Cesium 137 were represented by 30 round square sources covering the main spots of contamination. The results of calculation of contamination of the atmosphere for several cities of Belarus, Russia and Ukraine, where there are the permanent points of observation for the content of radionuclides in the air, have shown that the proposed model of dusting sources describes the contamination of near land air with Cesium 137 reasonably well. 7 refs., 3 tabs

  5. A Coupled Groundwater-Surface Water Modeling Framework for Simulating Transition Zone Processes.

    Science.gov (United States)

    Mugunthan, Pradeep; Russell, Kevin T; Gong, Binglei; Riley, Michael J; Chin, Arthur; McDonald, Blair G; Eastcott, Linda J

    2017-05-01

    There is an identified need for fully representing groundwater-surface water transition zone (i.e., the sediment zone that connects groundwater and surface water) processes in modeling fate and transport of contaminants to assist with management of contaminated sediments. Most existing groundwater and surface water fate and transport models are not dynamically linked and do not consider transition zone processes such as bioturbation and deposition and erosion of sediments. An interface module is developed herein to holistically simulate the fate and transport by coupling two commonly used models, Environmental Fluid Dynamics Code (EFDC) and SEAWAT, to simulate surface water and groundwater hydrodynamics, while providing an enhanced representation of the processes in the transition zone. Transition zone and surface water contaminant processes were represented through an enhanced version of the EFDC model, AQFATE. AQFATE also includes SEDZLJ, a state-of-the-science surface water sediment transport model. The modeling framework was tested on a published test problem and applied to evaluate field-scale two- and three-dimensional contaminant transport. The model accurately simulated concentrations of salinity from a published test case. For the field-scale applications, the model showed excellent mass balance closure for the transition zone and provided accurate simulations of all transition zone processes represented in the modeling framework. The model predictions for the two-dimensional field case were consistent with site-specific observations of contaminant migration. This modeling framework represents advancement in the simulation of transition zone processes and can help inform risk assessment at sites where contaminant sources from upland areas have the potential to impact sediments and surface water. © 2016, National Ground Water Association.

  6. Movement of contaminants in the unsaturated zone of the ...

    African Journals Online (AJOL)

    Subsurface conditions consisted nominally of a 1 m thick layer of silty sand with denser gravel at the bottom of it, underlain by a stiff sandy clay (residual granite), with the natural water table more than 15 m below ground surface. In summary, it can be deduced that movement in the unsaturated zone of bacterial indicators, ...

  7. Modeling Groundwater-Surface Water Interaction and Contaminant Transport of Chlorinated Solvent Contaminated Site

    Science.gov (United States)

    Yimer Ebrahim, Girma; Jonoski, Andreja; van Griensven, Ann; Dujardin, Juliette; Baetelaan, Okke; Bronders, Jan

    2010-05-01

    Chlorinated-solvent form one of the largest groups of environmental chemicals. Their use and misuse in industry have lead to a large entry of these chemicals into the environment, resulting in widespread dissemination and oftentimes environmental contamination. Chlorinated solvent contamination of groundwater resources has been widely reported. For instance, there has been much interest in the assessment of these contaminant levels and their evolutions with time in the groundwater body below the Vilvoorde-Machelen industrial area (Belgium). The long industrial history of the area has lead to complex patterns of pollution from multiple sources and the site has been polluted to the extent that individual plumes are not definable any more. Understanding of groundwater/surface water interaction is a critical component for determining the fate of contaminant both in streams and ground water due to the fact that groundwater and surface water are in continuous dynamic interaction in the hydrologic cycle. The interaction has practical consequences in the quantity and quality of water in either system in the sense that depletion and/or contamination of one of the system will eventually affect the other one. The transition zone between a stream and its adjacent aquifer referred to as the hyporheic zone plays a critical role in governing contaminant exchange and transformation during water exchange between the two water bodies. The hyporheic zone of Zenne River ( the main receptor ) is further complicated due to the fact that the river banks are artificially trained with sheet piles along its reach extending some 12 m below the surface. This study demonstrates the use of MODFLOW, a widely used modular three-dimensional block-centred finite difference, saturated flow model for simulating the flow and direction of movement of groundwater through aquifer and stream-aquifer interaction and the use of transport model RT3D, a three-dimensional multi-species reactive transport model

  8. Vulnerability of ground water to contamination, Edwards Aquifer recharge zone, Bexar County, Texas, 1998

    Science.gov (United States)

    Clark, Allan K.

    2000-01-01

    The Edwards aquifer, one of the most productive carbonate-rock aquifers in the Nation, is composed of the Kainer and Person Formations of the Edwards Group plus the overlying Georgetown Formation. Most recharge to the Edwards aquifer results from the percolation of streamflow loss and the infiltration of precipitation through porous parts of the recharge zone. Residential and commercial development is increasing, particularly in Bexar County in south-central Texas, atop the densely fractured and steeply faulted recharge zone. The increasing development has increased the vulnerability of ground water to contamination by spillage or leakage of waste materials, particularly fluids associated with urban runoff and (or) septic-tank leachate. This report describes a method of assessing the vulnerability of ground water to contamination in the Edwards aquifer recharge zone. The method is based on ratings of five natural features of the area: (1) hydraulic properties of outcropping hydrogeologic units; (2) presence or absence of faults; (3) presence or absence of caves and (or) sinkholes; (4) slope of land surface; and (5) permeability of soil. The sum of the ratings for the five natural features was used to develop a map showing the recharge zone's vulnerability to ground-water contamination.

  9. IMPACT ASSESSMENT OF EXISTING VADOSE ZONE CONTAMINATION AT THE HANFORD SITE SX TANK FARM

    International Nuclear Information System (INIS)

    KHALEEL R

    2007-01-01

    The USDOE has initiated an impact assessment of existing vadose zone contamination at the Hanford Site SX tank farm in southeastern Washington State. The assessment followed the Resource Conservation and Recovery Act (RCRA) Corrective Action process to address the impacts of past tank waste releases to the vadose zone at the single-shell tank farm. Numerical models were developed that consider the extent of contamination presently within the vadose zone and predict contaminant movement through the vadose zone to groundwater. The transport of representative mobile (technetium-99) and immobile (cesium-137) constituents was evaluated in modeling. The model considered the accelerated movement of moisture around and beneath single-shell tanks that is attributed to bare, gravel surfaces resulting from the construction of the underground storage tanks. Infiltration, possibly nearing 100 mm yr -1 , is further amplified in the tank farm because of the umbrella effect created by percolating moisture being diverted by the impermeable, sloping surface of the large, 24-m-diameter, buried tank domes. For both the base case (no-action alternative) simulation and a simulation that considered placement of an interim surface barrier to minimize infiltration, predicted, groundwater concentrations for technetium-99 at the SX tank farm boundary were exceedingly high, on the order of 10 6 pCi L -1 . The predicted concentrations are, however, somewhat conservative because of our use of two-dimensional modeling for a three-dimensional problem. A series of simulations were performed, using recharge rates of 50, 30, and 10 mm yr -1 , and compared to the basecase(100 mm yr -1 ) results. As expected, lowering meteoric recharge delayed peak arrival times and reduced peak concentrations at the tank farm boundary

  10. Impact Assessment of Existing Vadose Zone Contamination at the Hanford Site SX Tank Farm

    International Nuclear Information System (INIS)

    Khaleel, Raziuddin; White, Mark D.; Oostrom, Martinus; Wood, Marcus I.; Mann, Frederick M.; Kristofzski, John G.

    2007-01-01

    The USDOE has initiated an impact assessment of existing vadose zone contamination at the Hanford Site SX tank farm in southeastern Washington State. The assessment followed the Resource Conservation and Recovery Act (RCRA) Corrective Action process to address the impacts of past tank waste releases to the vadose zone at the single-shell tank farm. Numerical models were developed that consider the extent of contamination presently within the vadose zone and predict contaminant movement through the vadose zone to groundwater. The transport of representative mobile (technetium-99) and immobile (cesium-137) constituents was evaluated in modeling. The model considered the accelerated movement of moisture around and beneath single-shell tanks that is attributed to bare, gravel surfaces resulting from the construction of the underground storage tanks. Infiltration, possibly nearing 100 mm yr -1 , is further amplified in the tank farm because of the umbrella effect created by percolating moisture being diverted by the impermeable, sloping surface of the large, 24-m-diameter, buried tank domes. For both the base case (no-action alternative) simulation and a simulation that considered placement of an interim surface barrier to minimize infiltration, predicted groundwater concentrations for technetium-99 at the SX tank farm boundary were exceedingly high, on the order of 106 pCi L-1. The predicted concentrations are, however, somewhat conservative because of our use of two-dimensional modeling for a three-dimensional problem. A series of simulations were performed, using recharge rates of 50, 30, and 10 mm yr -1 , and compared to the base case (100 mm yr -1 ) results. As expected, lowering meteoric recharge delayed peak arrival times and reduced peak concentrations at the tank farm boundary.

  11. Description of measurement techniques for surface contaminations

    International Nuclear Information System (INIS)

    Bourrez, E.

    2001-01-01

    The needs of evaluation of the surface contamination are numerous in the processes of production and management of radioactive waste. The market of radiation protection materials proposes a lot of devices answering to the almost all these needs. These device have however their conditions and particular limits for use. To realize correct measurements it is use the device, the technique and the methods adapted to the need, by taking into account the optimization of economical aspect. (N.C.)

  12. Hard-surface contamination detection exercise

    Energy Technology Data Exchange (ETDEWEB)

    Kawa, S.

    1991-12-31

    The purpose of this thesis is to create a practical exercise which demonstrates the techniques used by Health Physicists to detect surface contamination, including both instrumentation and smear survey techniques. By understanding the basic principles of the most commonly found instruments the intent is that a new Health Physics graduate can correctly choose, and apply an instrument to their detection situation. The exercise is also intended to acquaint students with the very basic principles of smear techniques. Smear surveys are probably the most universally applied technique in this industry, however, very little literature exists on the subject. The techniques are usually taught, on-the-job and by demonstration. By their seeing and participating in this presentation, it is intended that Health Physics students can accelerate their first few weeks at their new careers, and enable them to recognize common mistakes. Health Physicists are expected to have knowledge of the basic practices of their profession. This exercise will allow Health Physics students to become familiar with the use of hand-held detection devices and the technique of smear surveys. Adequate measurement and recording of surface contamination information is necessary to: meet licensing requirements; protect the health and safety of the workers; maintain accurate records in the case of litigation or dose reconstruction; and maintain high levels of professional competency. This exercise will assist students in obtaining the skills necessary to adequately measure and record levels of surface contamination. 41 refs., 14 figs., 2 tabs.

  13. System for removing contaminated surface layers

    International Nuclear Information System (INIS)

    Yoshikawa, Kozo.

    1987-04-01

    The object of the present invention is to offer a new type of useful decontamination system, with which the contaminated surface layers can be removed effectively by injection of such solid microparticles. Liquid carbon dioxide is passed from a liquid carbon dioxide tank via the carbon dioxide supply line into the system for injecting solid carbon dioxide particles. Part of the liquid carbon dioxide introduced into the system is converted to solid carbon dioxide particles by the temperature drop resulting from adiabatic expansion in the carbon dioxide expansion space of the injection system. The solid carbon dioxide particles reach the injection nozzle, which is connected through the expansion space. The carbon dioxide microparticles are further cooled and accelerated by nitrogen gas injected from the nitrogen gas nozzle at the tip of the nitrogen gas supply line, which is connected to a liquid nitrogen tank. The cooled and accelerated solid carbon dioxide microparticles are injected from the injection nozzle for the solid carbon dioxide and directed against the contaminated surface to be cleaned, and, as a result, the surface contamination is removed

  14. 10 CFR Appendix D to Part 835 - Surface Contamination Values

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Surface Contamination Values D Appendix D to Part 835...—Surface Contamination Values The data presented in appendix D are to be used in identifying the need for posting of contamination and high contamination areas in accordance with § 835.603(e) and (f) and...

  15. Contamination detector for inner surface of container

    International Nuclear Information System (INIS)

    Watanabe, Tadao.

    1995-01-01

    The present invention concerns a device for detecting contamination of radioactive materials on the inner surface of a vessel upon reutilizing the vessel for containing solidified radioactive wastes and transporting them. Namely, the detecting device has following functions. (1) A radiation detector detects the radioactive materials on the inner surface of the vessel. (2) A plurality of proximity switches measure the distance from the radiation detector to the wall surface of the vessel and are actuated if the distance is decreased to a predetermined value, (3) A vessel inner surface position calculation mechanism calculates the position of the inner surface of the vessel based on the information from a direction indicator and a height indicator. (4) A frontal limit detector detects the limit for allowing the radiation detector to proceed. (5) A vessel inner shape judging mechanism for judging the shape of the inner side of the vessel based on the signals from the proximity switches in a state where the frontal limit detector is operated and a vessel inner surface position signal outputted from the vessel inner surface position calculation mechanism. As a result, the shape of the inner side of the vessel can accurately be recognized, thereby improving accuracy of radiation measurement. (I.S.)

  16. TWRS vadose zone contamination issue expert panel report

    Energy Technology Data Exchange (ETDEWEB)

    Shafer, D.S.

    1997-05-01

    When members were first canvassed for participation in the Vadose Zone Expert Panel the stated purpose for convening the Panel was to review a controversial draft report, the SX Tank Farm Report. This report was produced by a DOE Grand Junction Project Office (GJPO) contractor, RUST Geotech, now MACTEC-ERS, for the DOE Richland Office (DOERL). Three meetings were planned for June, July and August, 1995 to review the draft report and to complete a Panel report by mid-September. The Expert Panel has found its efforts confounded by various non-technical issues. The Expert Panel has chosen to address some of the non-technical issues in this Preface rather than to dilute the technical discussion that follows in the body of this independent expert panel status report (Panel Report). Rather than performing a straightforward manuscript review, the Panel was asked to resolve conflicting interpretations of gamma-ray logging measurements performed in vadose zone boreholes (drywells) surrounding the high-level radioactive wastes of the SX tank farm. There are numerous and complex technical issues that must be evaluated before the vertical and radial extent of contaminant migration at the SX tank farm can be accurately assessed. When the Panel first met in early June, 1996, it quickly became apparent that the scientific and technical issues were obscured by policy and institutional affairs which have polarized discussion among various segments of the Hanford organization. This situation reflects the kinds of institutional problems described separately in reports by the National Research Council of the National Academy of Sciences (NAS/NRC), The Hanford Tanks Environmental Impacts and Policy Choices and BmTiers to Science: Technical Management of the Department of Energy Environmental Remediation Program. The Vadose Zone Characterization Program, appears to be caught between conflicting pressures and organizational mandates, some imposed from outside DOE-RL and some self

  17. Cleanup Verification Package for the 118-H-6:2, 105-H Reactor Ancillary Support Areas, Below-Grade Structures, and Underlying Soils; the 118-H-6:3, 105-H Reactor Fuel Storage Basin and Underlying Soils; The 118-H-6:3 Fuel Storage Basin Deep Zone Side Slope Soils; the 100-H-9, 100-H-10, and 100-H-13 French Drains; the 100-H-11 and 100-H-12 Expansion Box French Drains; and the 100-H-14 and 100-H-31 Surface Contamination Zones

    Energy Technology Data Exchange (ETDEWEB)

    M. J. Appel

    2006-06-29

    This cleanup verification package documents completion of removal actions for the 105-H Reactor Ancillary Support Areas, Below-Grade Structures, and Underlying Soils (subsite 118-H-6:2); 105-H Reactor Fuel Storage Basin and Underlying Soils (118-H-6:3); and Fuel Storage Basin Deep Zone Side Slope Soils. This CVP also documents remedial actions for the following seven additional waste sties: French Drain C (100-H-9), French Drain D (100-H-10), Expansion Box French Drain E (100-H-11), Expansion Box French Drain F (100-H-12), French Drain G (100-H-13), Surface Contamination Zone H (100-H-14), and the Polychlorinated Biphenyl Surface Contamination Zone (100-H-31).

  18. Cleanup Verification Package for the 118-H-6:2, 105-H Reactor Ancillary Support Areas, Below-Grade Structures, and Underlying Soils; the 118-H-6:3, 105-H Reactor Fuel Storage Basin and Underlying Soils; the 118-H-6:6 Fuel Storage Basin Deep Zone Side Slope Soils; the 100-H-9, 100-H-10, and 100-H-13 French Drains; the 100-H-11 and 100-H-12 Expansion Box French Drains; and the 100-H-14 and 100-H-31 Surface Contamination Zones

    International Nuclear Information System (INIS)

    Appel, M.J.

    2006-01-01

    This cleanup verification package documents completion of removal actions for the 105-H Reactor Ancillary Support Areas, Below-Grade Structures, and Underlying Soils (subsite 118-H-6:2); 105-H Reactor Fuel Storage Basin and Underlying Soils (118-H-6:3); and Fuel Storage Basin Deep Zone Side Slope Soils. This CVP also documents remedial actions for the following seven additional waste sties: French Drain C (100-H-9), French Drain D (100-H-10), Expansion Box French Drain E (100-H-11), Expansion Box French Drain F (100-H-12), French Drain G (100-H-13), Surface Contamination Zone H (100-H-14), and the Polychlorinated Biphenyl Surface Contamination Zone (100-H-31)

  19. Characterization and Potential Remediation Approaches for Vadose Zone Contamination at Hanford 241-SX Tank Farm-13235

    International Nuclear Information System (INIS)

    Eberlein, Susan J.; Sydnor, Harold A.; Parker, Danny L.; Glaser, Danney R.

    2013-01-01

    Unplanned releases of radioactive and hazardous wastes have occurred at the 241-SX Tank Farm on the U.S. Department of Energy Hanford Site in southeast Washington State. Interim and long-term mitigation efforts are currently under evaluation for 241-SX Tank Farm. Two contiguous interim surface barriers have been designed for deployment at 241-SX Tank Farm to reduce future moisture infiltration; however, construction of the surface barriers has been deferred to allow testing of alternative technologies for soil moisture reduction and possibly contaminant source term reduction. Previous tests performed by other organizations at the Hanford Site have demonstrated that: vadose zone desiccation using large diameter (greater than 4 inch) boreholes is feasible; under certain circumstances, mobile contaminants may be removed in addition to water vapor; and small diameter (approximately 2 inch) boreholes (such as those placed by the direct push hydraulic hammer) can be used to perform vapor extractions. Evaluation of the previous work combined with laboratory test results have led to the design of a field proof-of-principle test to remove water and possibly mobile contaminants at greater depths, using small boreholes placed with the direct push unit

  20. RADIATION ACCESS ZONE AND VENTILATION CONFINEMENT ZONE CRITERIA FOR THE MGR SURFACE FACILITIES

    International Nuclear Information System (INIS)

    D. A. Padula

    2000-01-01

    The objectives of this technical report are to: (1) Establish the criteria for Radiation Access Zone (RAZ) designation. (2) Establish the criteria for the Ventilation Confinement Zone (VCZ) designation. The scope will be to formulate the RAZ and VCZ zoning designation for the Monitored Geologic Repository (MGR) surface facilities and to apply the zoning designations to the current Waste Handling Building (WHB), Waste Treatment Building (WTB), and Carrier Preparation Building (CPB) configurations

  1. Analysis of surface contaminants on beryllium and aluminum windows

    International Nuclear Information System (INIS)

    Gmur, N.F.

    1987-06-01

    An effort has been made to document the types of contamination which form on beryllium window surfaces due to interaction with a synchrotron radiation beam. Beryllium windows contaminated in a variety of ways (exposure to water and air) exhibited surface powders, gels, crystals and liquid droplets. These contaminants were analyzed by electron diffraction, electron energy loss spectroscopy, energy dispersive x-ray spectroscopy and wet chemical methods. Materials found on window surfaces include beryllium oxide, amorphous carbon, cuprous oxide, metallic copper and nitric acid. Aluminum window surface contaminants were also examined

  2. Geochemical Characterization of Chromate Contamination in the 100 Area Vadose Zone at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P. Evan; Qafoku, Nikolla; McKinley, James P.; Fruchter, Jonathan S.; Ainsworth, Calvin C.; Liu, Chongxuan; Ilton, Eugene S.; Phillips, J. L.

    2008-07-16

    of contaminant Cr travels fast through the sediments and appears as Cr(VI) in the effluents. The significance of this for groundwater concentrations would, however, depend on the mass flux of recharge to the water table. adsorption of Cr(VI) to sediments from spiked Cr(VI) solution is low; calculated retardation coefficients are close to one. Calcium polysulfide solutions readily reduced Cr(VI) to Cr(III) in column experiments. However a significant amount of the Cr(VI) was mobilized ahead of the polysulfide solution front. This has significant implications for in-situ reductive remediation techniques. The experiments suggest that it would be difficult to design a remedial measure using infiltration of liquid phase reductants without increasing transport of Cr(VI) toward the water table. The microscopic characterization results are consistent with the column studies. Cr(VI) is found as ubiquitous coatings on sediment grain surfaces. Small, higher concentration, chromium sites are associated with secondary clay mineral inclusions, with occasional barium chromate minerals, and reduced to Cr(III) in association with iron oxides that are most likely magnetite primary minerals. Within the restricted access domains of sediment matrix, ferrous iron could also diffuse from in situ, high-surface-area minerals to cause the reductive immobilization of chromate. This process may be favored at microscale geochemical zones where ferrous iron could be supplied. Once nucleated, micrometer-scale precipitates are favored as growing locales for further accumulation, causing the formation of discrete zones of Cr(III).

  3. Developments in surface contamination and cleaning fundamentals and applied aspects

    CERN Document Server

    Kohli, Rajiv

    2015-01-01

    Developments in Surface Contamination and Cleaning, Vol. 1: Fundamentals and Applied Aspects, Second Edition, provides an excellent source of information on alternative cleaning techniques and methods for characterization of surface contamination and validation. Each volume in this series contains a particular topical focus, covering the key techniques and recent developments in the area. This volume forms the heart of the series, covering the fundamentals and application aspects, characterization of surface contaminants, and methods for removal of surface contamination. In addition, new cleaning techniques effective at smaller scales are considered and employed for removal where conventional cleaning techniques fail, along with new cleaning techniques for molecular contaminants. The Volume is edited by the leading experts in small particle surface contamination and cleaning, providing an invaluable reference for researchers and engineers in R&D, manufacturing, quality control, and procurement specific...

  4. Influences of Flow Transients and Porous Medium Heterogeneity on Colloid-Associated Contaminant Transport in the Vadose Zone

    International Nuclear Information System (INIS)

    James Saiers

    2006-01-01

    Radionuclides, metals, and dense non-aqueous phase liquids have contaminated about six billion cubic meters of soil at Department of Energy (DOE) sites. The subsurface transport of many of these contaminants is facilitated by colloids (i.e., microscopic, waterborne particles). The first step in the transport of contaminants from their sources to off-site surface water and groundwater is migration through the vadose zone. Developing our understanding of the migration of colloids and colloid-associated contaminants through the vadose zone is critical to assessing and controlling the release of contaminants from DOE sites. In this study, we examined the mobilization, transport, and filtration (retention) of mineral colloids and colloid-associated radionuclides within unsaturated porous media. This investigation involved laboratory column experiments designed to identify properties that affect colloid mobilization and retention and pore-scale visualization experiments designed to elucidate mechanisms that govern these colloid-mass transfer processes. The experiments on colloid mobilization and retention were supplemented with experiments on radionuclide transport through porous media and on radionuclide adsorption to mineral colloids. Observations from all of these experiments--the column and visualization experiments with colloids and the experiments with radionuclides--were used to guide the development of mathematical models appropriate for describing colloids and colloid-facilitated radionuclide transport through the vadose zone

  5. Improvement of a device for monitoring the contamination of surfaces

    International Nuclear Information System (INIS)

    Barbier, Albert.

    1981-01-01

    The purpose of this invention is to make it possible to monitor the contamination of surfaces by a light weight portable device and enabling the alpha, beta and gamma radiation contamination to be detected. The detection probe which is connected by a single lead to the box is adapted, in each particular case, to the radiation mode emitted by the contaminated surfaces and the box is provided with a special leak-proof socket for connecting the probe and includes means for assessing the counting rate of the radiation given off, depending on the mode of the radiations emitted by the contaminated surfaces and the intensity of the count rate [fr

  6. Evaluation of deep vadose zone contaminant flux into groundwater: Approach and case study

    Science.gov (United States)

    Oostrom, M.; Truex, M. J.; Last, G. V.; Strickland, C. E.; Tartakovsky, G. D.

    2016-06-01

    For sites with a contaminant source located in the vadose zone, the nature and extent of groundwater contaminant plumes are a function of the contaminant flux from the vadose zone to groundwater. Especially for thick vadose zones, transport may be relatively slow making it difficult to directly measure contaminant flux. An integrated assessment approach, supported by site characterization and monitoring data, is presented to explain current vadose zone contaminant distributions and to estimate future contaminant flux to groundwater in support of remediation decisions. The U.S. Department of Energy Hanford Site (WA, USA) SX Tank Farm was used as a case study because of a large existing contaminant inventory in its deep vadose zone, the presence of a limited-extent groundwater plume, and the relatively large amount of available data for the site. A predictive quantitative analysis was applied to refine a baseline conceptual model through the completion of a series of targeted simulations. The analysis revealed that site recharge is the most important flux-controlling process for future contaminant flux. Tank leak characteristics and subsurface heterogeneities appear to have a limited effect on long-term contaminant flux into groundwater. The occurrence of the current technetium-99 groundwater plume was explained by taking into account a considerable historical water-line leak adjacent to one of the tanks. The analysis further indicates that the vast majority of technetium-99 is expected to migrate into the groundwater during the next century. The approach provides a template for use in evaluating contaminant flux to groundwater using existing site data and has elements that are relevant to other disposal sites with a thick vadose zone.

  7. Assessment of the feasibility of anaerobic composting for treatment of perchlorate - contaminated soils in a war zone

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Amin

    2015-01-01

    Full Text Available Aims: The objectives of this study were to determine the perchlorate concentrations in surface soils and assess feasibility of anaerobic bioremediation in full-scale for perchlorate-contaminated soils in a war zone. Materials and Methods: Fifteen samples of surface soil were collected using a composite sampling method in the study area. The soil samples, after extraction and preparation, were analyzed by ion chromatography. Anaerobic composting technique (soil excavation, mixing with manure, transfer into treatment cell and cover with a 6-mil high-density polyethylene liner considered to cleanup perchlorate-contaminated soil in a war zone. Results: The concentration of perchlorate in the soil surface samples ranged from 3 to 107.9 mg/kg, which is more than State advisory levels for residential and protection of domestic groundwater use pathway. This study indicates that technologies, skills, experience, raw materials (manure, lands, and machinery needed for implementation of full-scale composting, are available in the study area. Conclusions: Based on the results, anaerobic composting technique could be considered as a feasible, viable and cost-effective alternative for perchlorate bioremediation in the study area. According to the available of techniques and skills, successful experiences of anaerobic composting in other countries, and potential of study area, The application of anaerobic composting is technically feasible and can be use for perchlorate contaminated soil cleanup in a zone war.

  8. Surface Contamination by FTIR-PAS

    Science.gov (United States)

    Davis, Dennis M.; Hoffland, Lynn D.

    1985-12-01

    Fourier Transform Infrared Photoacoustic Spectroscopy (FTIR-PAS) is used to study the contamination of alkyd painted panels by liquids and solids. These alkyd painted panels are stainless steel panels coated with primer and an alkyd resin based paint which the Army uses for its vehicles. Portions of these panels were contaminated by dimethyl methyl phosphonate, tri-(2-ethylhexyl) phosphate, and triphenyl phosphate. The panels were then studied using FTIR-PAS, and the spectra identified.

  9. A study on unsaturated zone characterization and feasibility of soil vapor extraction at a DNAPL-contaminated site in Korea

    Science.gov (United States)

    Lee, Man Na Mi; Yeo, In Wook

    2013-04-01

    Groundwater contamination by Dense Non-Aqueous Phase Liquids (DNAPLs), such as trichloroethylene (TCE), have been found in many industrial complexes, which is one of the most pressing problems in contaminant hydrology. As DNAPL is denser than water, it migrates downward through the overlying sediments and water table, and there, it forms a long term source of contamination due to its low solubility in water. DNAPL research site, located in Wonju, Republic of Korea, is contaminated with TCE (trichloroethylene), which was used as solvent from 1988 to 1997, and contaminated top soil dug out up to 3 m deep in 2004 to 2005. However, a high concentration (15 mg/L) of TCE in groundwater exceeding drinking water standard (0.03 mg/L in Korea) is still detected in the source zone area. Recent studies showed that the rise in water table led to an increase in TCE concentration, indicating that TCE sources existed in unsaturated zone above/around the water table. Therefore, the purpose of this study aims to characterize unsaturated zone in terms of air permeability and flow connectivity between the boreholes penetrating unsaturated zone, which will consequently be used for the design of pilot scale soil vapor extraction (SVE) system. Five boreholes with three multi-level screens at the depth of 3.0 to 4.5 m, 5.5 to 7.0, and 8.0 to 12.0 m were installed at the source zone for field tests. Pneumatic tests were performed to determine the air permeability. The average air permeability was measured to be 2.18×10-6 cm2. Pressure-drawdown curve well matched leaky aquifer type, indicating that air leaks through the ground surface. Air flow tests were also carried out to investigate air flow connectivity between multi-level wells. When injecting air through the upper level of the well, vertical air flow toward the surface mainly took place with horizontal flow limited. On the other hand, when injecting air to the lower part, the horizontal air flow was well made through unsaturated

  10. Surface Wave Focusing and Acoustic Communications in the Surf Zone

    National Research Council Canada - National Science Library

    Preisig, James

    2004-01-01

    The forward scattering of acoustic signals off of shoaling surface gravity waves in the surf zone results in a time-varying channel impulse response that is characterized by intense, rapidly fluctuating arrivals...

  11. Mulching as a countermeasure for crop contamination within the 30 km zone of Chernobyl Nuclear Power Plant

    International Nuclear Information System (INIS)

    Yera, T.S.; Vallejo, R.; Tent, J.; Rauret, G.; Omelyanenko, N.; Ivanov, Y.

    1999-01-01

    The effect of mulch soil cover on crop contamination by 137 Cs was studied within the 30 km zone of Chernobyl Nuclear Power Plant. Experiments were performed with oats (Avena sativa) over a three year period. In 1992 soil surface was covered by a plastic net. In 1993 two straw mulch treatments were applied at a dose rate of 200 g m -2 using 137 Cs contaminated and clean straw, respectively. A similar mulch treatment was applied in 1994, and two mulch doses of clean straw were tested. Protection of the soil with a plastic net significantly increased crop yield and reduced crop contamination. When clean straw was used as a mulch layer, a significant decrease of about 30--40% in 137 Cs activity concentration was observed. Mulching with 137 Cs contaminated straw did not reduce crop contamination, probably due to an increase in soil available 137 Cs released from the contaminated mulch. Mulching has been shown to be an effective treatment both for reducing 137 Cs plant contamination and improving crop yield. Therefore, it can be considered as a potential countermeasure in a post-accident situation

  12. Movement of contaminants in the unsaturated zone of the ...

    African Journals Online (AJOL)

    2School of Civil, Environmental and Mining Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia. 3Palmer Development Group, P.O. Box 46830, Glosderry, Cape Town 7702, South Africa. ABSTRACT. This study measured the movement of contaminants in the ...

  13. Deciphering heavy metal contamination zones in soils of a granitic ...

    Indian Academy of Sciences (India)

    may enter the food chain or leach down to ground- water and contaminate drinking water resources. (Jeevan ... international airport that has been expanding at a fast pace and now has the distinction of being one of the ...... Abrahams P W 2002 Soils: Their implications to human health; The Science of the Total Environ.

  14. Deciphering heavy metal contamination zones in soils of a granitic ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 121; Issue 4 ... The spatial variation maps deciphering different zones of heavy metal concentration in the soil were generated in a GIS (geographic information system) based environment ... Department of Geology, Osmania University, Hyderabad 500 007, India.

  15. An evaluation of vapor extraction of vadose zone contamination

    International Nuclear Information System (INIS)

    Crotwell, A.T.; Waehner, M.J.; MacInnis, J.M.; Travis, C.C.; Lyon, B.F.

    1992-05-01

    An in-depth analysis of vapor extraction for remediation of soils contaminated with volatile organic compounds (VOCS) was conducted at 13 sites. The effectiveness of vapor extraction systems (VES) was evaluated on the basis of soil concentrations of VOCs and soil-gas concentrations of VOC's. The range of effectiveness was found to be 64%--99% effective in removing organic contaminants from soil. At nine of the 13 sites studied in this report, vapor extraction was found to be effective in reducing VOC cooncentrations by at least 90%. At the remaining four sites studied, vapor extraction was found to reduce VOC concentrations by less than 90%. Vapor extraction is ongoing at two of these sites. At a third, the ineffectiveness of the vapor extraction is attributed to the presence of ''hot spots'' of contamination. At the fourth site, where performance was found to be relatively poor, the presence of geological tar deposits at the site is thought to be a major factor in the ineffectiveness

  16. 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...

  17. Modeling of laser damage initiated by surface contamination

    International Nuclear Information System (INIS)

    Feit, M.D.; Rubenchik, A.M.; Faux, D.R.; Riddle, R.A.; Shapiro, A.; Eder, D.C.; Penetrante, B.M.; Milam, D.; Genin, F.Y.; Kozlowski, M.R.

    1996-11-01

    The authors are engaged in a comprehensive effort to understand and model the initiation and growth of laser damage initiated by surface contaminants. This includes, for example, the initial absorption by the contaminant, heating and plasma generation, pressure and thermal loading of the transparent substrate, and subsequent shockwave propagation, 'splashing' of molten material and possible spallation, optical propagation and scattering, and treatment of material fracture. The integration use of large radiation hydrodynamics codes, optical propagation codes and material strength codes enables a comprehensive view of the damage process The following picture of surface contaminant initiated laser damage is emerging from our simulations

  18. Distribution of metals and extent of contamination in sediments from the south-eastern Baltic Sea (Lithuanian zone

    Directory of Open Access Journals (Sweden)

    Nijolė Remeikaitė-Nikienė

    2018-04-01

    Full Text Available Summary: The distribution of metals (Pb, Cu, Cd, Ni, Cr, Zn in surface sediments and the potential pollution sources in the south-eastern part (SE of the Baltic Sea (Lithuanian zone were investigated in relation to the environmental characteristics (amount of fine-grained particles, TOC content in sediments, origin of sedimentary organic matter, salinity, water depth in 2011–2014. The higher metal concentrations were measured in sediments of the Curonian Lagoon and in the open waters. An approach using various environmental indices (enrichment factor EF, geoaccumulation index Igeo and contamination factor CF was used to quantitatively assess a contamination degree. The principal component analysis (PCA was applied in order to further scrutinize pollution from metal sources. The values of the contamination indices showed no/very low sediment contamination with Ni and Cr, minor–moderate contamination with Cu, Zn and Pb and moderate–considerable pollution with Cd. The strong relationships among metals suggested their similar distribution pattern and a combination of natural and anthropogenic sources. The higher metal concentrations coincided with an increasing amount of fine-grained fraction and organic carbon. In the territorial waters, the distribution of elements was related to the water depth. In addition, the binding of metals with insoluble iron sulphides might explain their high concentrations at the most remote and deepest stations. Keywords: Metals, Enrichment factor, Geoaccumulation index, Contamination factor, The Baltic Sea, The Curonian Lagoon

  19. Potential effects of groundwater and surface water contamination in an urban area, Qus City, Upper Egypt

    Science.gov (United States)

    Abdalla, Fathy; Khalil, Ramadan

    2018-05-01

    The potential effects of anthropogenic activities, in particular, unsafe sewage disposal practices, on shallow groundwater in an unconfined aquifer and on surface water were evaluated within an urban area by the use of hydrogeological, hydrochemical, and bacteriological analyses. Physicochemical and bacteriological data was obtained from forty-five sampling points based on33 groundwater samples from variable depths and 12 surface water samples. The pollution sources are related to raw sewage and wastewater discharges, agricultural runoff, and wastewater from the nearby Paper Factory. Out of the 33 groundwater samples studied, 17 had significant concentrations of NO3-, Cl- and SO42-, and high bacteria counts. Most of the water samples from the wells contained high Fe, Mn, Pb, Zn, Cd, and Cr. The majority of surface water samples presented high NO3- concentrations and high bacteria counts. A scatter plot of HCO3- versus Ca indicates that 58% of the surface water samples fall within the extreme contamination zone, while the others are within the mixing zone; whereas 94% of groundwater samples showed evidence of mixing between groundwater and wastewater. The bacteriological assessment showed that all measured surface and groundwater samples contained Escherichia coli and total coliform bacteria. A risk map delineated four classes of contamination, namely, those sampling points with high (39.3%), moderate (36.3%), low (13.3%), and very low (11.1%) levels of contamination. Most of the highest pollution points were in the middle part of the urban area, which suffers from unmanaged sewage and industrial effluents. Overall, the results demonstrate that surface and groundwater in Qus City are at high risk of contamination by wastewater since the water table is shallow and there is a lack of a formal sanitation network infrastructure. The product risk map is a useful tool for prioritizing zones that require immediate mitigation and monitoring.

  20. Application of geospatial modelling technique in delineation of fluoride contamination zones within Dwarka Basin, Birbhum, India

    OpenAIRE

    Thapa, Raju; Gupta, Srimanta; Reddy, D.V.

    2016-01-01

    Dwarka River Basin is one of the fluoride affected river basin in Birbhum, West Bengal. In the present research work, various controlling factors for fluoride contamination in groundwater i.e., geology, aquifer type, groundwater table, soil, rainfall, geomorphology, drainage density, land use land cover, lineament and fault density, slope and elevation were considered to delineate the potential fluoride contamination zones within Dwarka River Basin in Birbhum. Assigning weights and ranks to v...

  1. Some aspects of radioactive contamination and decontamination of the Chernobyl' NPP accident zone territory

    International Nuclear Information System (INIS)

    Samojlenko, Yu.N.; Nad''yarnykh, G.V.; Teplitskij, A.L.; Shilin, S.A.

    1989-01-01

    Data are presented on the radioactive contamination of the 30-km zone, on the radionuclide (RN) distribution in soils and on the RN migration in grounds. During 1986-1988 were tested over 20 techniques for territory decontamination and were found out the most optimal ones. The first stage of decontamination was removal of an upper contaminated soil layer. The second stage was prolonged chemical fixation of dusting decontaminated soil areas. 3 tabs

  2. Optimization of fodder rations for intensive development of cattle-breeding in an radioactive contaminated zone

    International Nuclear Information System (INIS)

    Stolyarov, G.V.

    1999-01-01

    It has been calculated some variants of the optimal structure of milk cow herd's fodder rations in a radioactive contaminated zone in dependence of the contamination density. Rations were balanced in primary nutritive including digestible protein. It has been determined their costs and specific radioactivity of cesium-137. These fodder rations can be recommended to the farms of the Gomel Region suffered from the Chernobyl nuclear power station explosion

  3. Contaminant Flux Reduction Barriers for Managing Difficult to Treat Source Zones in Unconsolidated Media

    Science.gov (United States)

    2017-06-20

    ER-201328) Contaminant Flux Reduction Barriers for Managing Difficult-to-Treat Source Zones in Unconsolidated Media June 2017 This document has...the time for reviewing instructions, searching existing data sources , gathering and maintaining the data needed, and completing and reviewing this...Treat Source Zones in Unconsolidated Media 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER ER-201328 Poonam R

  4. Contaminant Flux Reduction Barriers for Managing Difficult-to-Treat Source Zones in Unconsolidated Media

    Science.gov (United States)

    2017-06-20

    FINAL REPORT Contaminant Flux Reduction Barriers for Managing Difficult-to- Treat Source Zones in Unconsolidated Media ESTCP Project ER-201328...instructions, searching existing data sources , gathering and maintaining the data needed, and completing and reviewing this collection of information. Send...Treat Source Zones in Unconsolidated Media 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER ER-201328 Poonam R

  5. LASER CLEANING OF CONTAMINATED PAINTED SURFACES

    Energy Technology Data Exchange (ETDEWEB)

    Ames A. Grisanti; Charlene R. Crocker; Robert R. Jensen

    1999-11-19

    Several techniques are available or under development for surface decontamination in nuclear facilities. Each technique has its merits; however, none of them is universally the best choice for all surface decontamination applications. Because of the multitude of factors which influence the environmental and economic aspects of selecting a surface decontamination technique, it is difficult to select the best method in a given situation; an objective basis for comparing techniques is needed. The objective of this project was to develop a software tool for use by personnel selecting a surface decontamination technique. The software incorporates performance data for available surface decontamination techniques. The beta release version of the Surface Decontamination Assistant Software has been completed and has undergone testing at the Energy and Environmental Research Center. Minor modifications to the software were completed, and a final release version of the software is ready to be issued.

  6. Chaotic-Dynamical Conceptual Model to Describe Fluid Flow and Contaminant Transport in a Fractured Vadose Zone

    International Nuclear Information System (INIS)

    Faybishenko, Boris; Doughty, Christine; Geller, Jil T.

    1999-01-01

    DOE faces the remediation of numerous contaminated sites, such as those at Hanford, INEEL, LLNL, and LBNL, where organic and/or radioactive wastes were intentionally or accidentally released to the vadose zone from surface spills, underground tanks, cribs, shallow ponds, and deep wells. Migration of these contaminants through the vadose zone has led to the contamination of (or threatens to contaminate) underlying groundwater. A key issue in choosing a corrective action plan to clean up contaminated sites is the determination of the location, total mass, mobility and travel time to receptors for contaminants moving in the vadose zone. These problems are difficult to solve in a technically defensible and accurate manner because contaminants travel downward intermittently, through narrow pathways, driven by variations in environmental conditions. These preferential flow pathways can be difficult to find and predict. The primary objective of this project is to determine if and when dynamical chaos theory can be used to investigate infiltration of fluid and contaminant transport in heterogeneous soils and fractured rocks. The objective of this project is being achieved through the following activities: Development of multi scale conceptual models and mathematical and numerical algorithms for flow and transport, which incorporate both (a) the spatial variability of heterogeneous porous and fractured media and (b) the temporal dynamics of flow and transport; Development of appropriate experimental field and laboratory techniques needed to detect diagnostic parameters for chaotic behavior of flow; Evaluation of chaotic behavior of flow in laboratory and field experiments using methods from non-linear dynamics; Evaluation of the impact these dynamics may have on contaminant transport through heterogeneous fractured rocks and soils and remediation efforts. This approach is based on the consideration of multi scale spatial heterogeneity and flow phenomena that are affected by

  7. Automatic Measurement of Low Level Contamination on Concrete Surfaces

    International Nuclear Information System (INIS)

    Tachibana, M.; Itoh, H.; Shimada, T.; Yanagihara, S.

    2002-01-01

    Automatic measurement of radioactivity is necessary for considering cost effectiveness in final radiological survey of building structures in decommissioning nuclear facilities. The RAPID (radiation measuring pilot device for surface contamination) was developed to be applied to automatic measurement of low level contamination on concrete surfaces. The RAPID has a capability to measure contamination with detection limit of 0.14 Bq/cm2 for 60Co in 30 seconds of measurement time and its efficiency is evaluated to be 5 m2/h in a normal measurement option. It was confirmed that low level contamination on concrete surfaces could be surveyed by the RAPID efficiently compared with direct measurement by workers through its actual application

  8. Effect of radioactive contamination of hydrobionts within the thirty-kilometer zone of Chernobylsk NPP

    International Nuclear Information System (INIS)

    Ryabov, I.N.

    1992-01-01

    A study was made of hydrobionts, particularly fishes, living within the thirty-kilometer control zone of Chernobyl NPP and northern part of the Kiev basin, after the disaster. Out of 31 fish species living in the NPP cooling pond some were idendified which were mostly affected by radioactive contamination. They were predators belonging, with respect to reproduction and development, to a lithophilous group

  9. The forming of the complexes of soil mezofauna in the zone of radioactive contamination

    International Nuclear Information System (INIS)

    Maksimova, S.L.

    2002-01-01

    We carried out the pedobiological research in the different biogeocenoses in the zone of radioactive contamination. Based on the obtained data we can conclude a direct correlation between the viability of the soil invertebrates and the background gamma-radiation intensity. All the facts indicate that soil animal complexes in biogeocenoses exposed to radiation for a long time impact clearly noticeable suppression

  10. Transport of contaminants by Arctic sea ice and surface ocean currents

    International Nuclear Information System (INIS)

    Pfirman, S.

    1995-01-01

    Sea ice and ocean currents transport contaminants in the Arctic from source areas on the shelves, to biologically active regions often more than a thousand kilometers away. Coastal regions along the Siberian margin are polluted by discharges of agricultural, industrial and military wastes in river runoff, from atmospheric deposition and ocean dumping. The Kara Sea is of particular concern because of deliberate dumping of radioactive waste, as well as the large input of polluted river water. Contaminants are incorporated in ice during suspension freezing on the shelves, and by atmospheric deposition during drift. Ice releases its contaminant load through brine drainage, surface runoff of snow and meltwater, and when the floe disintegrates. The marginal ice zone, a region of intense biological activity, may also be the site of major contaminant release. Potentially contaminated ice from the Kara Sea is likely to influence the marginal ice zones of the Barents and Greenland seas. From studies conducted to date it appears that sea ice from the Kara Sea does not typically enter the Beaufort Gyre, and thus is unlikely to affect the northern Canadian and Alaskan margins

  11. ARPEGES, a method to assess the risk of surface waters contamination by pesticides at the national scale

    OpenAIRE

    Malavaud, C.; Bougon, N.; Carluer, N.; Le Henaff, G.; Piffady, J.; Tormos, T.; Gouy, V.

    2014-01-01

    Arpeges is an innovating and coherent method to assess the potential surface water’s contamination by pesticides at the national scale. In France, it was implemented at Water Framework Directive water bodies’ scale. The objectives are to identify of vulnerable zones and to determinate the main risk factors implied in pollution transfer according to the considered zones. Actually, this method allows a better understanding and a ranking of pollution’s causes considering three ...

  12. Interfacial Reduction-Oxidation Mechanisms Governing Fate and Transport of Contaminants in the Vadose Zone

    Energy Technology Data Exchange (ETDEWEB)

    Principal Investigator: Baolin Deng, University of Missouri, Columbia, MO; Co-Principal Investigator: Silvia Sabine Jurisson, University of Missouri, Columbia, MO; Co-Principal Investigator: Edward C. Thornton, Pacific Northwest National Laboratory Richland, WA; Co-Principal Investigator: Jeff Terry, Illinois Institute of Technology, Chicago, IL

    2008-05-12

    There are many soil contamination sites at the Department of Energy (DOE) installations that contain radionuclides and toxic metals such as uranium (U), technetium (Tc), and chromium (Cr). Since these contaminants are the main 'risk drivers' at the Hanford site (WA) and some of them also pose significant risk at other DOE facilities (e.g., Oak Ridge Reservation - TN; Rocky Flats - CO), development of technologies for cost effective site remediation is needed. Current assessment indicates that complete removal of these contaminants for ex-situ disposal is infeasible, thus in-situ stabilization through reduction to insoluble species is considered one of the most important approaches for site remediation. In Situ Gaseous Reduction (ISGR) is a technology developed by Pacific Northwest National Laboratory (PNNL) for vadose zone soil remediation. The ISGR approach uses hydrogen sulfide (H{sub 2}S) for reductive immobilization of contaminants that show substantially lower mobility in their reduced forms (e.g., Tc, U, and Cr). The technology can be applied in two ways: (i) to immobilize or stabilize pre-existing contaminants in the vadose zone soils by direct H{sub 2}S treatment, or (ii) to create a permeable reactive barrier (PRB) that prevents the migration of contaminants. Direct treatment involves reduction of the contaminants by H{sub 2}S to less mobile species. Formation of a PRB is accomplished through reduction of ferric iron species in the vadose zone soils by H{sub 2}S to iron sulfides (e.g., FeS), which provides a means for capturing the contaminants entering the treated zone. Potential future releases may occur during tank closure activities. Thus, the placement of a permeable reactive barrier by ISGR treatment can be part of the leak mitigation program. Deployment of these ISGR approaches, however, requires a better understanding of the immobilization kinetics and mechanisms, and a better assessment of the long-term effectiveness of treatment. The

  13. Analysis of surface contaminants on beryllium windows

    International Nuclear Information System (INIS)

    Gmur, N.F.

    1986-12-01

    It is known that various crystalline and liquid compounds form on the downstream surfaces of beryllium windows exposed to air. It is also known that the integrity of such windows may be compromised resulting in leaks through the window. The purpose of this report is to document the occurrences described as they pertain to the NSLS and to analyze, where possible, the various substances formed

  14. Release of Streptomyces albus propagules from contaminated surfaces

    International Nuclear Information System (INIS)

    Gorny, R.L.; Mainelis, Gediminas; Grinshpun, Sergey A.; Willeke, Klaus; Dutkiewicz, Jacek; Reponen, Tiina

    2003-01-01

    The release of Streptomyces albus propagules from contaminated agar an ceiling tile surfaces was studied under controlled environmental condition in a newly developed aerosolization chamber. The experiments revealed tha both spores and cell fragments can be simultaneously released from the colonized surface by relatively gentle air currents of 0.3 m s -1 . A 100x increase of the air velocity can result in a 50-fold increase in the number of released propagules. The aerosolization rate depends strongly on the typ and roughness of the contaminated surface. Up to 90% of available actinomycete propagules can become airborne during the first 10 min of th release process. Application of vibration to the surface did not reveal an influence on the aerosolization process of S. albus propagules under th tested conditions. This study has shown that propagules in the fine particle size range can be released in large amounts from contaminated surfaces Measurement of the number of S. albus fragments in the vicinity of contaminated area, as an alternative to conventional air or surface sampling appears to be a promising approach for quantitative exposure assessment

  15. Removal of lead contaminated dusts from hard surfaces.

    Science.gov (United States)

    Lewis, Roger D; Condoor, Sridhar; Batek, Joe; Ong, Kee Hean; Backer, Denis; Sterling, David; Siria, Jeff; Chen, John J; Ashley, Peter

    2006-01-15

    Government guidelines have widely recommended trisodium phosphate (TSP) or "lead-specific" cleaning detergents for removal of lead-contaminated dust (LCD) from hard surfaces, such as floors and window areas. The purpose of this study was to determine if low-phosphate, non-lead-specific cleaners could be used to efficiently remove LCD from 3 types of surfaces (vinyl flooring, wood, and wallpaper). Laboratory methods were developed and validated for simulating the doping, embedding, and sponge cleaning of the 3 surface types with 4 categories of cleaners: lead-specific detergents, nonionic cleaners, anionic cleaners, and trisodium phosphate (TSP). Vinyl flooring and wood were worn using artificial means. Materials were ashed, followed by ultrasound extraction, and anodic stripping voltammetry (ASV). One-way analysis of variance approach was used to evaluate the surface and detergent effects. Surface type was found to be a significant factor in removal of lead (p < 0.001). Vinyl flooring cleaned better than wallpaper by over 14% and wood cleaned better than wallpaper by 13%. There was no difference between the cleaning action of vinyl flooring and wood. No evidence was found to support the use of TSP or lead-specific detergents over all-purpose cleaning detergents for removal of lead-contaminated dusts. No-phosphate, non-lead-specific detergents are effective in sponge cleaning of lead-contaminated hard surfaces and childhood lead prevention programs should consider recommending all-purpose household detergents for removal of lead-contaminated dust after appropriate vacuuming.

  16. Unsaturated zone leaching models for assessing risk to groundwater of contaminated sites

    DEFF Research Database (Denmark)

    Troldborg, Mads; Binning, Philip John; Nielsen, Signe

    2009-01-01

    Risk assessments of sites contaminated with organic contaminants are typically conducted using models that ignore gas phase transport in the unsaturated zone. Here a general approach to developing analytical solutions to multiphase transport is presented. The approach is based on a combined gas......, lateral gas diffusion, sorption and degradation; a simple one-dimensional screening model, and two one-dimensional radial gas diffusion models for use in simulating volatile organic contaminant diffusion in unsaturated soils with an impermeable cover. The models show that both degradation and diffusion...... are important mechanisms for attenuation of contaminant concentrations at the water table. Finally, model results are compared with field data to illustrate the applicability of the solutions in risk assessment....

  17. Evaluating Contaminant Flux from the Vadose Zone to the Groundwater in the Hanford Central Plateau. SX Tank Farms Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Last, George V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tartakovsky, Guzel D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-01

    At the DOE Hanford Site, contaminants were discharged to the subsurface through engineered waste sites in the Hanford Central Plateau. Additional waste was released through waste storage tank leaks. Much of the contaminant inventory is still present within the unsaturated vadose zone sediments. The nature and extent of future groundwater contaminant plumes and the growth or decline of current groundwater plumes beneath the Hanford Central Plateau are a function of the contaminant flux from the vadose zone to the groundwater. In general, contaminant transport is slow through the vadose zone and it is difficult to directly measure contaminant flux in the vadose zone. Predictive analysis, supported by site characterization and monitoring data, was applied using a structured, systems-based approach to estimate the future contaminant flux to groundwater in support of remediation decisions for the vadose zone and groundwater (Truex and Carroll 2013). The SX Tank Farm was used as a case study because of the existing contaminant inventory in the vadose zone, observations of elevated moisture content in portions of the vadose zone, presence of a limited-extent groundwater plume, and the relatively large amount and wide variety of data available for the site. Although the SX Tank Farm case study is most representative of conditions at tank farm sites, the study has elements that are also relevant to other types of disposal sites in the Hanford Central Plateau.

  18. Hydrodynamic Characterization of a Surface Storage Zone in a Natural Stream

    Science.gov (United States)

    Sandoval Ulloa, J. C.; Escauriaza, C. R.; Mignot, E.; Mao, L.

    2015-12-01

    Flow developed in surface storage zones in rivers is very important for many physical and biogeochemical processes. These regions are characterized by low velocities compared to the flow in the main channel and long residence times that favor the deposition of contaminants, nutrient uptake and interactions with reactive sediments. The dynamics of the turbulent flows in these zones is very complex, typically characterized by a shear layer that induces a recirculating area, with multiple large-scale coherent structures of different temporal and spatial scales. In this work we present the methodology and analysis of measurements in a natural surface storage zone. We report detailed information of a field campaign carried out in the Lluta River, located in northern Chile in the high altitude Andean environment known as the Altiplano (~4,000 masl). The area of study has great interest for the river ecosystem, since the water has high concentration levels of arsenic and other metals. The Lluta River is also a water source for many agricultural communities and urban centers located in the lower parts of the watershed. Field information obtained was: detailed topography, 3D velocity components in several points, and sediment arsenic concentration in the main channel and in the recirculating region of the natural surface storage zone. Topography was obtained through DGPS and digital image processing. The 3D velocity field was measured with an acoustic Doppler velocimeter (ADV) and surface velocity data was obtained through the LSPIV technique. Arsenic concentration was obtained by sediment sampling analysis. With this data we analyze the flow topology and characteristics features of the velocity, which constitute the controlling mechanisms of contaminant transport in the field. In addition, we contrast with preliminary results of a three-dimensional (3D) numerical simulation, to determine the influence of different parameters on the transport and mixing processes in natural

  19. Monitoring of tritium-contaminated surfaces, including skin

    International Nuclear Information System (INIS)

    Surette, R.A.; Wood, M.J.

    1994-05-01

    We have examined various commercially available tritium surface contamination monitors along with different swipe media and techniques for direct and indirect (swipe) monitoring of contaminated surfaces, including skin. None of the methods or instruments evaluated were more sensitive than the swipe and liquid scintillation counting (LSC) method. Swipe measurements with open-window proportional counters were, in general, less than half as sensitive as LSC, but have the advantages of having the results available almost immediately, and no sample preparation is required. The Nuclear Measurement Corporation's PC-55 is the most suitable instrument we tested for the analysis of routine swipe measurement. The PC-55 was about one third as sensitive as LSC when used with Ontario Hydro filter paper swipe media. Surface contamination measurement results can be obtained within minutes using the PC-55, compared to hours using LSC. The selection of swipe media for use with proportional counter-based instruments is critical. A medium that is electrically insulating can develop an electrostatic charge on its surface; this may alter the field gradient in the detector and may adversely influence the results. Although the PC-55 is sufficiently sensitive and very convenient, operational experience with the instrument is needed before recommending that it replace current LSC methods. The PC-55's susceptibility to internal tritium contamination may limit its practical usefulness. Because of the complexity of using live animals to evaluate direct and indirect methods for assessing skin contamination, pig skin was investigated as a possible substitute. We concluded that, for the first few hours post-exposure, pig skin mimics the kinetics of animal skin that has contacted a tritium-contaminated surface. (author). 30 refs., 1 tab., 7 figs

  20. GWSCREEN: A semi-analytical model for assessment of the groundwater pathway from surface or buried contamination: Theory and user's manual

    International Nuclear Information System (INIS)

    Rood, A.S.

    1992-03-01

    GWSCREEN was developed for assessment of the groundwater pathway from leaching of radioactive and non radioactive substances from surface or buried sources. The code was designed for implementation in the Track 1 and Track 2 assessment of Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) sites identified as low probability hazard at the Idaho National Engineering Laboratory (DOE, 1991). The code calculates the limiting soil concentration such that regulatory contaminant levels in groundwater are not exceeded. The code uses a mass conservation approach to model three processes: Contaminant release from a source volume, contaminant transport in the unsaturated zone, and contaminant transport in the saturated zone. The source model considers the sorptive properties and solubility of the contaminant. Transport in the unsaturated zone is described by a plug flow model. Transport in the saturated zone is calculated with a semi-analytical solution to the advection dispersion equation for transient mass flux input

  1. Investigation of zones with increased ground surface gamma radiation

    International Nuclear Information System (INIS)

    Butkus, D.V.; Morkunas, G.S.; Styro, B.I.

    1989-01-01

    Measurements of the increased gamma radiation zones of soils were conducted in the South-Western part of the Litvinian. The shores of lakes in the north-eastern part of the Suduva high land were investigated. the maximum values of the gamma radiation dose rates were distributed along the lake shores at a distance of 1 m from the water surface, while farther than 1.5 m from it the dose rate was close to the natural value. The increased gamma radiation intensity zones on the ground surface were found only at the northern (Lake Reketija) or the western shore (other lakes under investigation). The highest values of the gamma radiation dose 200-600 μR/h (0.5-1.5 nGy/s) were observed in the comparatively small areas (up to several square metres). The gamma radiation intensity of soil surface increased strongly moving towards the point where the maximum intensity was obsered. 10 figs

  2. Worker exposures from recycling surface contaminated radioactive scrap metal

    Energy Technology Data Exchange (ETDEWEB)

    Kluk, A. [Dept. of Energy, Germantown, MD (United States); Phillips, J.W.; Culp, J. [Analytical Services, Inc., Columbia, MD (United States)

    1996-12-31

    Current DOE policy permits release from DOE control of real property with residual levels of surficial radioactive contamination if the contamination is below approved guidelines. If the material contains contamination that is evenly distributed throughout its volume (referred to as volumetric contamination), then Departmental approval for release must be obtained in advance. Several DOE sites presently recycle surface contaminated metal, although the quantities are small relative to the quantities of metal processed by typical mini-mills, hence the potential radiation exposures to mill workers from processing DOE metals and the public from the processed metal are at present also a very small fraction of their potential value. The exposures calculated in this analysis are based on 100% of the scrap metal being processed at the maximum contamination levels and are therefore assumed to be maximum values and not likely to occur in actual practice. This paper examines the relationship between the surface contamination limits established under DOE Order 5400.5, {open_quotes}Radiation Protection of the Public and the Environment,{close_quotes} and radiation exposures to workers involved in the scrap metal recycling process. The analysis is limited to surficial contamination at or below the guideline levels established in DOE Order 5400.5 at the time of release. Workers involved in the melting and subsequent fabrication of products are not considered radiation workers (no requirements for monitoring) and must be considered members of the public. The majority of the exposures calculated in this analysis range from tenths of a millirem per year (mrem/yr) to less than 5 mrem/yr. The incremental risk of cancer associated with these exposures ranges from 10{sup -8} cancers per year to 10{sup -6} cancers per year.

  3. Worker exposures from recycling surface contaminated radioactive scrap metal

    International Nuclear Information System (INIS)

    Kluk, A.; Phillips, J.W.; Culp, J.

    1996-01-01

    Current DOE policy permits release from DOE control of real property with residual levels of surficial radioactive contamination if the contamination is below approved guidelines. If the material contains contamination that is evenly distributed throughout its volume (referred to as volumetric contamination), then Departmental approval for release must be obtained in advance. Several DOE sites presently recycle surface contaminated metal, although the quantities are small relative to the quantities of metal processed by typical mini-mills, hence the potential radiation exposures to mill workers from processing DOE metals and the public from the processed metal are at present also a very small fraction of their potential value. The exposures calculated in this analysis are based on 100% of the scrap metal being processed at the maximum contamination levels and are therefore assumed to be maximum values and not likely to occur in actual practice. This paper examines the relationship between the surface contamination limits established under DOE Order 5400.5, open-quotes Radiation Protection of the Public and the Environment,close quotes and radiation exposures to workers involved in the scrap metal recycling process. The analysis is limited to surficial contamination at or below the guideline levels established in DOE Order 5400.5 at the time of release. Workers involved in the melting and subsequent fabrication of products are not considered radiation workers (no requirements for monitoring) and must be considered members of the public. The majority of the exposures calculated in this analysis range from tenths of a millirem per year (mrem/yr) to less than 5 mrem/yr. The incremental risk of cancer associated with these exposures ranges from 10 -8 cancers per year to 10 -6 cancers per year

  4. Lead mobilisation in the hyporheic zone and river bank sediments of a contaminated stream. Contribution to diffuse pollution

    Energy Technology Data Exchange (ETDEWEB)

    Palumbo-Roe, Barbara; Wragg, Joanna; Banks, Vanessa J. [British Geological Survey, Keyworth Nottingham (United Kingdom)

    2012-12-15

    Purpose: Past metal mining has left a legacy of highly contaminated sediments representing a significant diffuse source of contamination to water bodies in the UK and worldwide. This paper presents the results of an integrated approach used to define the role of sediments in contributing to the dissolved lead (Pb) loading to surface water in a mining-impacted catchment. Materials and methods: The Rookhope Burn catchment, northern England, UK is affected by historical mining and processing of lead ore. Quantitative geochemical loading determinations, measurements of interstitial water chemistry from the stream hyporheic zone and inundation tests of bank sediments were carried out. Results and discussion: High concentrations of Pb in the sediments from the catchment, identified from the British Geological Survey Geochemical Baseline Survey of the Environment (GBASE) data, demonstrate both the impact of mineralisation and widespread historical mining. The results from stream water show that the stream Pb load increased in the lower part of the catchment, without any apparent or significant contribution of point sources of Pb to the stream. Relative to surface water, the interstitial water of the hyporheic zone contained high concentrations of dissolved Pb in the lower reaches of the Rookhope Burn catchment, downstream of a former mine washing plant. Concentrations of 56 {mu}g l{sup -1} of dissolved Pb in the interstitial water of the hyporheic zone may be a major cause of the deterioration of fish habitats in the stream and be regarded as a serious risk to the target of good ecological status as defined in the European Water Framework Directive. Inundation tests provide an indication that bank sediments have the potential to contribute dissolved Pb to surface water. Conclusions: The determination of Pb in the interstitial water and in the inundation water, taken with water Pb mass balance and sediment Pb distribution maps at the catchment scale, implicate the

  5. Application of geospatial modelling technique in delineation of fluoride contamination zones within Dwarka Basin, Birbhum, India

    Directory of Open Access Journals (Sweden)

    Raju Thapa

    2017-09-01

    Full Text Available Dwarka River Basin is one of the fluoride affected river basin in Birbhum, West Bengal. In the present research work, various controlling factors for fluoride contamination in groundwater i.e., geology, aquifer type, groundwater table, soil, rainfall, geomorphology, drainage density, land use land cover, lineament and fault density, slope and elevation were considered to delineate the potential fluoride contamination zones within Dwarka River Basin in Birbhum. Assigning weights and ranks to various inputs factor class and their sub-class respectively was carried out on the basis of knowledge driven method. Weighted overlay analysis was carried out to generate the final potential fluoride contamination zones which are classified into two broad classes i.e., ‘high’ and ‘low’, and it is observed that major portion of the study area falls under low fluoride contamination category encompassing 88.61% of the total area which accounts for 759.48 km2 and high fluoride contaminated region accounts for 11.40% of the total study area encompassing an area of about 97.67 km2. Majority of high fluoride areas fall along the flood plain of Dwarka River Basin. Finally, for validation 197 reported points within Dwarka having fluoride in underground water are overlaid and an overall accuracy of 92.15% is observed. An accuracy of 83.21% and 84.24% is obtained for success and prediction rate curve respectively.

  6. Explosive Contamination from Substrate Surfaces: Differences and Similarities in Contamination Techniques using RDX and C-4

    Energy Technology Data Exchange (ETDEWEB)

    C.J. Miller; T.S. Yoder

    2010-06-01

    The amount of time that an explosive is present on the surface of a material is dependent upon the original amount of explosive on the surface, temperature, humidity, rain, etc. This laboratory study focused on looking at similarities and differences in three different surface contamination techniques that are used when performance testing explosive trace detection equipment in an attempt to determine how effective the techniques are at replicating actual field samples. The three techniques used were dry transfer deposition of solutions using the Transportation Security Laboratory (TSL) patented dry transfer techniques (US patent 6470730), direct deposition of explosive standards, and fingerprinting of actual explosives. Explosives were deposited on the surface of one of five substrates using one of the three different deposition techniques. The process was repeated for each surface type using each contamination technique. The surface types used were: 50% cotton/50% polyester as found in T-shirts, 100% cotton with a smooth surface such as that found in a cotton dress shirt, 100% cotton on a rough surface such as that found on canvas or denim, suede leather such as might be found on jackets, purses, or shoes, and metal obtained from a car hood at a junk yard. The samples were not pre-cleaned prior to testing and contained sizing agents, and in the case of the metal, oil and dirt. The substrates were photographed using a Zeiss Discover V12 stereoscope with Axiocam ICc1 3 megapixel digital camera to determine the difference in the crystalline structure and surface contamination in an attempt to determine differences and similarities associated with current contamination techniques.

  7. Assessment of arsenic surface contamination in a museum anthropology department.

    Science.gov (United States)

    Gribovich, Andrey; Lacey, Steven; Franke, John; Hinkamp, David

    2013-02-01

    To assess potential arsenic (As) contamination of work surfaces to improve upon the control strategy at an anthropology department in a large natural history museum. Work practices were observed and control strategy reviewed to inform an occupational hygiene assessment strategy utilizing surface wipe sampling. A total of 35 sampling targets were identified, focusing on surfaces that receive high touch traffic, including workstations, artifact transport carts, and elevator buttons. Arsenic sampling and analysis were performed using reference method Occupational Safety and Health Administration ID-125G. Four of the sampling areas returned detectable levels of As, ranging from 0.052 to 0.350 μg/100 cm. Workplace observations and wipe sampling data enabled the development of recommendations to help to further reduce potential occupational exposure to As. Continuous reduction of surface contamination is prudent for known human carcinogens.

  8. Purification the surface of detail from biological contaminations

    International Nuclear Information System (INIS)

    Gabdrakhmanov, Az T; Israphilov, I H; Galiakbarov, A T; Gabdrakhmanov, Al T

    2017-01-01

    More than 70% of biodegradation occur due to the corrosion processes. A biological corrosion causes the greatest damage to the oil and gas-production industry, the Navy and pipelines, constructions of water supply, means of communication. This paper proposes an effective method of purification various surfaces from biological contaminations by using of cold plasma. (paper)

  9. Geochemical Characterization of Chromate Contamination in the 100 Area Vadose Zone at the Hanford Site - Part 2

    Energy Technology Data Exchange (ETDEWEB)

    Qafoku, Nikolla; Dresel, P. Evan; McKinley, James P.; Ilton, Eugene S.; Um, Wooyong; Resch, Charles T.; Kukkadapu, Ravi K.; Petersen, Scott W.

    2011-01-04

    At the Hanford Site, chromate was used throughout the 100 Areas (100-B, 100-C, 100-D/DR, 100-F, 100-H, and 100 K) as a corrosion inhibitor in reactor cooling water. Chromate was delivered in rail cars, tanker trucks, barrels, and local pipelines as dichromate granular solid or stock solution. In many occasions, chromate was inevitably discharged to surface or near-surface ground through spills during handling, pipeline leaks, or during disposal to cribs. The composition of the liquids that were discharged is not known and it is quite possible that Cr(VI) fate and transport in the contaminated sediments would be a function of the chemical composition of the waste fluids. The major objectives of this investigation which was limited in scope by the financial resources available, were to 1) determine the leaching characteristics of hexavalent chromium [Cr(VI)] from contaminated sediments collected from 100-D Area spill sites; 2) elucidate possible Cr(VI) mineral and/or chemical associations that may be responsible for Cr(VI) retention in the Hanford Site 100 Areas through the use of macroscopic leaching studies, and microscale characterization of contaminated sediments; and 3) provide information to construct a conceptual model of Cr(VI) geochemistry in the Hanford 100 Area vadose zone that can be used for developing options for environmental remediation. The information gathered from this research effort will help to further improve our understanding of Cr(VI) behavior in the vadose zone and will also help in accelerating the 100 Area Columbia River Corridor cleanup by providing valuable information to develop remedial action based on a fundamental understanding of Cr(VI) vadose zone geochemistry. A series of column experiments were conducted with contaminated sediments to study Cr(VI) desorption patterns. Column experiments used the field size fraction of the sediment samples and a simulated Hanford Site groundwater solution. Periodic stop flow events were applied to

  10. Using Contaminant Transport Modeling to Determine Historical Discharges at the Surface

    Science.gov (United States)

    Fogwell, T. W.

    2013-12-01

    When it is determined that a contaminated site needs to be remediated, the issue of who is going to pay for that remediation is an immediate concern. This means that there needs to be a determination of who the responsible parties are for the existing contamination. Seldom is it the case that records have been made and kept of the surface contaminant discharges. In many cases it is possible to determine the relative amount of contaminant discharge at the surface of the various responsible parties by employing a careful analysis of the history of contaminant transport through the surface, through the vadose zone, and within the saturated zone. The process begins with the development of a dynamic conceptual site model that takes into account the important features of the transport of the contaminants through the vadose zone and in the groundwater. The parameters for this model can be derived from flow data available for the site. The resulting contaminant transport model is a composite of the vadose zone transport model, together with the saturated zone (groundwater) flow model. Any calibration of the model should be carefully employed in order to avoid using information about the conclusions of the relative discharge amounts of the responsible parties in determining the calibrated parameters. Determination of the leading edge of the plume is an important first step. It is associated with the first discharges from the surface of the site. If there were several discharging parties at the same time, then it is important to establish a chemical or isotopic signature of the chemicals that were discharged. The time duration of the first discharger needs to be determined as accurately as possible in order to establish the appropriate characterization of the leading portion of the resulting plume in the groundwater. The information about the first discharger and the resulting part of the plume associated with this discharger serves as a basis for the determination of the

  11. Remediation of Deep Vadose Zone Radionuclide and Metal Contamination: Status and Issues

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P. Evan; Truex, Michael J.; Cantrell, Keri

    2008-12-30

    This report documents the results of a PNNL literature review to report on the state of maturity of deep vadose zone remediation technologies for metal contaminants including some radionuclides. Its recommendations feed into decisionmakers need for scientific information and cost-effective in situ remediation technlogies needed under DOE's Environmental Management initiative Enhanced Remediation Methods: Scientific & Technical Basis for In Stu Treatment Systems for Metals and Radionuclides.

  12. A geometric approach to joint inversion with applications to contaminant source zone characterization

    International Nuclear Information System (INIS)

    Aghasi, Alireza; Mendoza-Sanchez, Itza; Miller, Eric L; Ramsburg, C Andrew; Abriola, Linda M

    2013-01-01

    This paper presents a new joint inversion approach to shape-based inverse problems. Given two sets of data from distinct physical models, the main objective is to obtain a unified characterization of inclusions within the spatial domain of the physical properties to be reconstructed. Although our proposed method generally applies to many types of inverse problems, the main motivation here is to characterize subsurface contaminant source zones by processing down-gradient hydrological data and cross-gradient electrical resistance tomography observations. Inspired by Newton's method for multi-objective optimization, we present an iterative inversion scheme in which descent steps are chosen to simultaneously reduce both data-model misfit terms. Such an approach, however, requires solving a non-smooth convex problem at every iteration, which is computationally expensive for a pixel-based inversion over the whole domain. Instead, we employ a parametric level set technique that substantially reduces the number of underlying parameters, making the inversion computationally tractable. The performance of the technique is examined and discussed through the reconstruction of source zone architectures that are representative of dense non-aqueous phase liquid (DNAPL) contaminant release in a statistically homogenous sandy aquifer. In these examples, the geometric configuration of the DNAPL mass is considered along with additional information about its spatial variability within the contaminated zone, such as the identification of low and high saturation regions. Comparison of the reconstructions with the true DNAPL architectures highlights the superior performance of the model-based technique and joint inversion scheme. (paper)

  13. Enzyme-enabled responsive surfaces for anti-contamination materials.

    Science.gov (United States)

    Wu, Songtao; Buthe, Andreas; Jia, Hongfei; Zhang, Minjuan; Ishii, Masahiko; Wang, Ping

    2013-06-01

    Many real-life stains have origins from biological matters including proteins, lipids, and carbohydrates that act as gluing agents binding along with other particulates or microbes to exposed surfaces of automobiles, furniture, and fabrics. Mimicking naturally occurring self-defensive processes, we demonstrate in this work that a solid surface carrying partially exposed enzyme granules protected the surface in situ from contamination by biological stains and fingerprints. Attributed to the activities of enzymes which can be made compatible with a wide range of materials, such anti-contamination and self-cleaning functionalities are highly selective and efficient toward sticky chemicals. This observation promises a new mechanism in developing smart materials with desired anti-microbial, self-reporting, self-cleaning, or self-healing functions. Copyright © 2013 Wiley Periodicals, Inc.

  14. Experiment on Physical Desalinisation of Uranium-contaminated Gravel Surface

    International Nuclear Information System (INIS)

    Park, Uk-Ryang; Kim, Gye-Nam; Kim, Seung-Soo; Han, Gyu-Seong; Moon, Jai-Kwon

    2014-01-01

    As a result, the method to wash uranium-contaminated gravels could not get satisfactory desalinization rate. During the long oxidization process it was judged that uranium penetrated inside the gravels, so we tried to increase the desalinization rate by fragmentizing them into pieces and then washing them. The desalinization rate after fragmentizing the gravels into pieces and washing them brought a satisfactory result.. However, we could obtain desired concentration for gravels with high uranium concentration by fragmentizing them and breaking them further into even smaller pieces. Likewise, desalinization using soil washing process is complicated and has to go through multiple washing steps, resulting in too much of waste fluid generated accordingly. The increase of waste fluid generated leads to the increase in by-products of the final disposal process later on, bringing a not good economic result. Furthermore, taking into account that the desalinization rate is 65% during soil washing process, it is expected that gravel washing will show a similar desalinization result; it is considered uneasy to have a perfect desalinization only by soil washing. The grinding method is actually used in the primary desalinization process in order to desalinize radioactivity-contaminated concrete. This method does desalinization by grinding the radioactivity-contaminated area of the concrete surface with desalinization equipment, which enables a near-to-perfect desalinization for relatively thinly contaminated surface. Likewise, this research verified the degree of desalinization by applying the grinding method and comparing it to the fragmentizing-washing method, and attempted to find a method to desalinize uranium-contaminated gravels more effectively. In order to desalinize uranium-contaminated gravels more effectively and compare to the existing washing-desalinization method, we conducted a desalinization experiment with grinding method that grinds gravel surface. As a

  15. Influence of Clastic Dikes on Vertical Migration of Contaminants in the Vadose Zone at Hanford

    International Nuclear Information System (INIS)

    Murray, Christopher J.; Ward, Anderson L.; Wilson, John L.

    2003-01-01

    The purpose of this study was to examine the hypothesis that clastic dikes could form a preferential flow path through the vadose zone to the water table at the Hanford Site. Clastic dikes are subvertical structures that form within sedimentary sequences after deposition, and cut across the original sedimentary layers. They are common throughout the Hanford Site, often occurring in organized polygonal networks. In the initial phase of the project, we analyzed the large-scale geometry of the clastic dikes and developed an algorithm for simulating their spatial distribution. This result will be useful in providing maps of the potential distribution of clastic dikes in areas where they are not exposed at the surface (e.g., where covered by windblown sand or by construction of facilities like tank farms at the surface). In addition to the study of the large scale distribution of the dikes, a major focus of the project was on field, laboratory, and modeling studies of the hydrogeologic al properties of the clastic dikes and the effect that they have on transport of water through the vadose zone. These studies were performed at two field locations at the Hanford Site. We performed an extensive series of field and laboratory measurements of a large number of samples from the clastic dikes, linked with infrared (IR) and visual imagery of the clastic dikes and surrounding matrix. We developed a series of correlations from the sample data that allowed us to estimate the unsaturated hydraulic conductivity of the dike and matrix at an extremely high resolution (approximately 1 mm). The resulting grids, each of which measured several meters on a side and included nearly 4 grid nodes, were used to study the distribution of moisture between the clastic dike and surrounding matrix, as well as the relative velocities that moisture would have through the clastic dike and matrix for a number of different recharge scenarios. Results show the development of complex flow networks that

  16. 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,

  17. Reactor surface contamination stabilization. Innovative technology summary report

    International Nuclear Information System (INIS)

    1998-11-01

    Contaminated surfaces, such as the face of a nuclear reactor, need to be stabilized (fixed) to avoid airborne contamination during decontamination and decommissioning activities, and to prepare for interim safe storage. The traditional (baseline) method of fixing the contamination has been to spray a coating on the surfaces, but ensuring complete coverage over complex shapes, such as nozzles and hoses, is difficult. The Hanford Site C Reactor Technology Demonstration Group demonstrated innovative technologies to assess stabilization properties of various coatings and to achieve complete coverage of complex surfaces on the reactor face. This demonstration was conducted in two phases: the first phase consisted of a series of laboratory assessments of various stabilization coatings on metal coupons. For the second phase, coatings that passed the laboratory tests were applied to the front face of the C Reactor and evaluated. The baseline coating (Rust-Oleum No. 769) and one of the innovative technologies did not completely cover nozzle assemblies on the reactor face, the most critical of the second-phase evaluation criteria. However, one of the innovative coating systems, consisting of a base layer of foam covered by an outer layer of a polymeric film, was successful. The baseline technology would cost approximately 33% as much as the innovative technology cost of $64,000 to stabilize an entire reactor face (196 m 2 or 2116 ft 2 ) with 2,004 nozzle assemblies, but the baseline system failed to provide complete surface coverage

  18. A biogeochemical transport model to simulate the attenuation of chlorinated hydrocarbon contaminant fluxes across the groundwater-surface water interface

    DEFF Research Database (Denmark)

    Malaguerra, Flavio; Binning, Philip John; Albrechtsen, Hans-Jørgen

    2009-01-01

    Chlorinated hydrocarbons originating from point sources are amongst the most prevalent contaminants of ground water and surface water resources. Riparian zones may play an important role in the attenuation of contaminant concentrations when contaminant plumes flow from groundwater to surface water...... because of the occurrence of redox gradients, strongly reductive conditions and high biological activity. In order to meet the expectations of the EU Water Framework Directive, an evaluation of the impact of such plumes on surface water is needed. The aim of this work is to develop a groundwater transport...... number of geochemical processes, allows the simulation of soil geochemical transformations when microbial by-products are released to surface water, and the consideration of non-linear feedbacks on bacterial growth and pollutant transformations. Sensitivity analysis is performed through Monte Carlo...

  19. A new type of 3H surface-contamination monitor.

    Science.gov (United States)

    Aoyama, T; Watanabe, T

    1985-06-01

    A new type of 3H surface-contamination monitor has been developed which uses a windowless air proportional counter as the detector. The monitor offers several advantages. First, a high detection efficiency is obtained for 3H beta rays due to the windowless construction of the detector, permitting a minimum detection level of less than 10(-4) muCi cm-2 for surface contamination by 3H. Second, since no special gases other than room air are used as the counter gas, gas cylinders are not required thereby permitting increased convenience and lower costs. Finally, the detector is insensitive to external light due to the height discrimination of proportional counter pulses, which allows the monitor to be used in brightly illuminated places.

  20. Removable coating for contamination protection of concrete surface

    International Nuclear Information System (INIS)

    Brambilla, G.; Beaulardi, L.

    1985-01-01

    In order to research protective coatings for concrete surfaces, assuring an effective protection against contamination and that it be easily removed before dismantling the structures, commercial stripping paints have been characterized for their conventional and nuclear properties: water and chemicals, abrasion, impact, tensile stress resistance, stripping capacity, decontaminability. The protective power of the coatings against contamination has been checked by recording the surface activity before and after stripping the paint film: the activity filtered through the coating was, in any case, very low (< 1% of the deposited activity). Indications from large scale application of a stripping paint in NUCLEO (Rome) establishments and technical evaluation of the possible utilization of removable coatings in the CAORSO Nuclear Power Station, are also reported

  1. Hanford Site surface soil radioactive contamination control plan, March 1993

    International Nuclear Information System (INIS)

    Mix, P.D.; Winship, R.A.

    1993-04-01

    The Decommissioning and Resource Conservation and Recovery Act Closure Program is responsible to the US Department of Energy Richland Field Office, for the safe and cost-effective surveillance, maintenance, and decommissioning of surplus facilities and Resource Conservation and Recovery Act of 1976 closures at the Hanford Site. This program also manages the Radiation Area Remedial Action that includes the surveillance, maintenance, decontamination, and/or interim stabilization of inactive burial grounds, cribs, ponds, trenches, and unplanned release sites. This plan addresses only the Radiation Area Remedial Action activity requirements for managing and controlling the contaminated surface soil areas associated with these inactive sites until they are remediated as part of the Hanford Site environmental restoration process. All officially numbered Radiation Area Remedial Action and non-Radiation Area Remedial Action contaminated surface soil areas are listed in this document so that a complete list of the sites requiring remediation is contained in one document

  2. Calibration and verification of surface contamination meters --- Procedures and techniques

    International Nuclear Information System (INIS)

    Schuler, C; Butterweck, G.; Wernli, C.; Bochud, F.; Valley, J.-F.

    2007-03-01

    A standardised measurement procedure for surface contamination meters (SCM) is presented. The procedure aims at rendering surface contamination measurements to be simply and safely interpretable. Essential for the approach is the introduction and common use of the radionuclide specific quantity 'guideline value' specified in the Swiss Radiation Protection Ordinance as unit for the measurement of surface activity. The according radionuclide specific 'guideline value count rate' can be summarized as verification reference value for a group of radionuclides ('basis guideline value count rate'). The concept can be generalized for SCM of the same type or for SCM of different types using he same principle of detection. A SCM multi source calibration technique is applied for the determination of the instrument efficiency. Four different electron radiation energy regions, four different photon radiation energy regions and an alpha radiation energy region are represented by a set of calibration sources built according to ISO standard 8769-2. A guideline value count rate representing the activity per unit area of a surface contamination of one guideline value can be calculated for any radionuclide using instrument efficiency, radionuclide decay data, contamination source efficiency, guideline value averaging area (100 cm 2 ), and radionuclide specific guideline value. n this way, instrument responses for the evaluation of surface contaminations are obtained for radionuclides without available calibration sources as well as for short-Iived radionuclides, for which the continuous replacement of certified calibration sources can lead to unreasonable costs. SCM verification is based on surface emission rates of reference sources with an active area of 100 cm 2 . The verification for a given list of radionuclides is based on the radionuclide specific quantity guideline value count rate. Guideline value count rates for groups of radionuclides can be represented within the maximum

  3. Hard-surface contamination detection exercise. [Smears:a3

    Energy Technology Data Exchange (ETDEWEB)

    Kawa, S.

    1991-01-01

    The purpose of this thesis is to create a practical exercise which demonstrates the techniques used by Health Physicists to detect surface contamination, including both instrumentation and smear survey techniques. By understanding the basic principles of the most commonly found instruments the intent is that a new Health Physics graduate can correctly choose, and apply an instrument to their detection situation. The exercise is also intended to acquaint students with the very basic principles of smear techniques. Smear surveys are probably the most universally applied technique in this industry, however, very little literature exists on the subject. The techniques are usually taught, on-the-job and by demonstration. By their seeing and participating in this presentation, it is intended that Health Physics students can accelerate their first few weeks at their new careers, and enable them to recognize common mistakes. Health Physicists are expected to have knowledge of the basic practices of their profession. This exercise will allow Health Physics students to become familiar with the use of hand-held detection devices and the technique of smear surveys. Adequate measurement and recording of surface contamination information is necessary to: meet licensing requirements; protect the health and safety of the workers; maintain accurate records in the case of litigation or dose reconstruction; and maintain high levels of professional competency. This exercise will assist students in obtaining the skills necessary to adequately measure and record levels of surface contamination. 41 refs., 14 figs., 2 tabs.

  4. Removal of Microbial Contamination from Surface by Plasma

    Science.gov (United States)

    Feng, Xinxin; Liu, Hongxia; Shen, Zhenxing; Wang, Taobo

    2018-01-01

    Microbial contamination is closely associated with human and environmental health, they can be tested on food surfaces, medical devices, packing material and so on. In this paper the removal of the microbial contamination from surface using plasma treatment is investigated. The Escherichia coli (E. coli) has been chosen as a bio-indicator enabling to evaluate the effect of plasma assisted microbial inactivation. Oxygen gas was as the working gas. The plasma RF power, plasma exposition time, gas flow and the concentration of organic pollutant were varied in order to see the effect of the plasma treatment on the Gram-negative germ removal. After the treatment, the microbial abatement was evaluated by the standard plate count method. This proved a positive effect of the plasma treatment on Gram-negative germ removal. The kinetics and mathematical model of removal were studied after plasma treatment, and then the removing course of E. coli was analyzed. This work is meaningful for deepening our understanding of the fundamental scientific principles regarding microbial contamination from surface by plasma.

  5. Aquatic ecosystems within the Chernobyl NPP exclusion zone: radioactive contamination, doses and effects

    International Nuclear Information System (INIS)

    Gudkov, D.I.; Kuzmenko, M.I.; Krot, Y.G.; Kipnis, L.S.; Mardarevich, M.G.; Ponomaryov, A.V.; Derevets, V.V.; Nazarov, A.B.

    2003-01-01

    For past 17 years after accident the character of radioactive contamination of water objects within the Chernobyl NPP exclusion zone has undergone essential changes. First of all it connected with realisation on a wide area of deactivation works, and also with transformation of radioactive substances in water-soil systems. Besides, during 1991-95 the complex of hydraulic engineering structures as protection dams, interfering washing away of radioactive substances from soils of the left-bank catchment basin and changed a hydrological regime of these territories during a high water, was constructed. The levels of radionuclide contamination of water objects within the Chernobyl NPP exclusion zone was rather stabilised. Due to high water change rate the river bottom sediments have undergone decontamination processes (especially during floods and periods of high water) and over the years have ceased to play the essential role as a secondary source of water contamination. On the other hand, the closed reservoirs have considerably higher levels of radioactive contamination caused by limited water change and by relatively high concentration of radionuclides deposited in the bottom sediments. Therefore, for the majority of standing reservoirs the level of radionuclide content is determined mainly by the rates of mobile radionuclide forms exchange between bottom sediment and water, as well as by the external washout from the catchment basin. In this paper will be considered: (1) the latest data on radionuclide content (Sr-90, Cs-137, Pu-238, Pu-239+240 and Am-241) and dynamics in water, seston, bottom sediments and hydrobionts of different trophic levels and ecological groups; (2) the peculiarities of formation of vegetative communities from lakes within embankment territory of Pripyat River flood-lands and its impact on radionuclide redistribution in aquatic ecosystems; (3) the major hydrochemical factors, which determine the behaviour of radionuclides in the aquatic

  6. Width of surface rupture zone for thrust earthquakes: implications for earthquake fault zoning

    Directory of Open Access Journals (Sweden)

    P. Boncio

    2018-01-01

    Full Text Available The criteria for zoning the surface fault rupture hazard (SFRH along thrust faults are defined by analysing the characteristics of the areas of coseismic surface faulting in thrust earthquakes. Normal and strike–slip faults have been deeply studied by other authors concerning the SFRH, while thrust faults have not been studied with comparable attention. Surface faulting data were compiled for 11 well-studied historic thrust earthquakes occurred globally (5.4 ≤ M ≤ 7.9. Several different types of coseismic fault scarps characterize the analysed earthquakes, depending on the topography, fault geometry and near-surface materials (simple and hanging wall collapse scarps, pressure ridges, fold scarps and thrust or pressure ridges with bending-moment or flexural-slip fault ruptures due to large-scale folding. For all the earthquakes, the distance of distributed ruptures from the principal fault rupture (r and the width of the rupture zone (WRZ were compiled directly from the literature or measured systematically in GIS-georeferenced published maps. Overall, surface ruptures can occur up to large distances from the main fault ( ∼ 2150 m on the footwall and  ∼  3100 m on the hanging wall. Most of the ruptures occur on the hanging wall, preferentially in the vicinity of the principal fault trace ( >   ∼  50 % at distances  <   ∼  250 m. The widest WRZ are recorded where sympathetic slip (Sy on distant faults occurs, and/or where bending-moment (B-M or flexural-slip (F-S fault ruptures, associated with large-scale folds (hundreds of metres to kilometres in wavelength, are present. A positive relation between the earthquake magnitude and the total WRZ is evident, while a clear correlation between the vertical displacement on the principal fault and the total WRZ is not found. The distribution of surface ruptures is fitted with probability density functions, in order to define a criterion to

  7. Dynamics of formation of the Exclusion Zone near hydrophilic surfaces

    Science.gov (United States)

    De Ninno, Antonella

    2017-01-01

    EZ water is unable to host solutes, what provides the root of the name Exclusion Zone, and its formation law points towards a diffusive process. These peculiarities have attracted the interest of scientists because it challenges all the theories which have tried to describe the structure of liquid water. The mixture of H-bond stable and H-bond distorted structures envisaged by very recent experimental findings, cannot account for the long-lived hexagonal configuration observed near the Nafion surface. A theoretical account for the phenomenology of H-bond is provided which looks able to explain many among the most striking feature of this water.

  8. Explosive Contamination from Substrate Surfaces: Differences and Similarities in Contamination Techniques Using RDX and C-4

    Science.gov (United States)

    Miller, C. J.; Yoder, T. S.

    2010-06-01

    Explosive trace detection equipment has been deployed to airports for more than a decade. During this time, the need for standardized procedures and calibrated trace amounts for ensuring that the systems are operating properly and detecting the correct explosive has been apparent but a standard representative of a fingerprint has been elusive. Standards are also necessary to evaluate instrumentation in the laboratories during development and prior to deployment to determine sample throughput, probability of detection, false positive/negative rates, ease of use by operator, mechanical and/or software problems that may be encountered, and other pertinent parameters that would result in the equipment being unusable during field operations. Since many laboratories do not have access to nor are allowed to handle explosives, the equipment is tested using techniques aimed at simulating the actual explosives fingerprint. This laboratory study focused on examining the similarities and differences in three different surface contamination techniques that are used to performance test explosive trace detection equipment in an attempt to determine how effective the techniques are at replicating actual field samples and to offer scenarios where each contamination technique is applicable. The three techniques used were dry transfer deposition of standard solutions using the Transportation Security Laboratory’s (TSL) patented dry transfer techniques (US patent 6470730), direct deposition of explosive standards onto substrates, and fingerprinting of actual explosives onto substrates. RDX was deposited on the surface of one of five substrates using one of the three different deposition techniques. The process was repeated for each substrate type using each contamination technique. The substrate types used were: 50% cotton/50% polyester as found in T-shirts, 100% cotton with a smooth surface such as that found in a cotton dress shirt, 100% cotton on a rough surface such as that

  9. Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone.

    Science.gov (United States)

    Bonzom, Jean-Marc; Hättenschwiler, Stephan; Lecomte-Pradines, Catherine; Chauvet, Eric; Gaschak, Sergey; Beaugelin-Seiller, Karine; Della-Vedova, Claire; Dubourg, Nicolas; Maksimenko, Andrey; Garnier-Laplace, Jacqueline; Adam-Guillermin, Christelle

    2016-08-15

    The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely unknown. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the functioning of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black alder at (i) eleven distant forest sites differing in ambient radiation levels (0.22-15μGyh(-1)) and (ii) along a short distance gradient of radioactive contamination (1.2-29μGyh(-1)) within a single forest in the Chernobyl exclusion zone. In addition to measuring ambient external dose rates, we estimated the average total dose rates (ATDRs) absorbed by decomposers for an accurate estimate of dose-induced ecological consequences of radioactive pollution. Taking into account potential confounding factors (soil pH, moisture, texture, and organic carbon content), the results from the eleven distant forest sites, and from the single forest, showed increased litter mass loss with increasing ATDRs from 0.3 to 150μGyh(-1). This unexpected result may be due to (i) overcompensation of decomposer organisms exposed to radionuclides leading to a higher decomposer abundance (hormetic effect), and/or (ii) from preferred feeding by decomposers on the uncontaminated leaf litter used for our experiment compared to locally produced, contaminated leaf litter. Our data indicate that radio-contamination of forest ecosystems over more than two decades does not necessarily have detrimental effects on organic matter decay. However, further studies are needed to unravel the underlying mechanisms of the results reported here, in order to draw firmer conclusions on how radio-contamination affects decomposition and associated ecosystem processes. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Radiological effects on populations of Oligochaeta in the Chernobyl contaminated zone

    Energy Technology Data Exchange (ETDEWEB)

    Tsytsugina, V.G.; Polikarpov, G.G. E-mail: ggp@iur.sebastopol.ua

    2003-07-01

    A detailed investigation of 3 populations of Oligochaete species (Dero obtusa, Nais pseudobtusa and Nais pardalis) has been carried out in contaminated lake of the close-in Chernobyl zone and in a control lake. Hydrochemical indices and concentrations of heavy metals, chloro-organi compounds and {sup 90}Sr in bottom sediments have been measured. Absorbed doses were calculated on the basis of the results of radiochemical analysis an assessed directly with thermoluminescent dosimeters (TLD). Stimulation of paratomous division (asexual reproduction) was found in one species of worm (D. obtusa), and activation of sexual reproduction in the two other specie studied. An increase in the amount of cytogenetic damage in the somatic cells of worms from the contaminated lake was found and an attempt was made to assess the relative contributions of radiation and chemical exposure on the basis of analyses of inter-cellular aberration distributions and the types of chromosome aberrations observed in the cells.

  11. A comprehensive analysis of contaminant transport in the vadose zone beneath tank SX-109

    International Nuclear Information System (INIS)

    Ward, A.L.; Gee, G.W.; White, M.D.

    1997-02-01

    The Vadose Zone Characterization Project is currently investigating the subsurface distribution of gamma-emitting radionuclides in S and SX Waste Management Area (WMA-S-SX) located in the 200 West Area of the US Department of Energy's Hanford Site in southeastern Washington State. Spectral-gamma logging of boreholes has detected elevated 137 Cs concentrations as deep as 38 m, a depth considered excessive based on the assumed geochemistry of 137 Cs in Hanford sediments. Routine groundwater sampling under the Resource Conservation and Recovery Act (RCRA) have also detected elevated levels of site-specific contaminants downgradient of WMA-S-SX. The objective of this report is to explore the processes controlling the migration of 137 Cs, 99 Tc, and NO 3 through the vadose zone of WMA-S-SX, particularly beneath tank SX-109

  12. Electronic Noses for Composites Surface Contamination Detection in Aerospace Industry.

    Science.gov (United States)

    Vito, Saverio De; Miglietta, Maria Lucia; Massera, Ettore; Fattoruso, Grazia; Formisano, Fabrizio; Polichetti, Tiziana; Salvato, Maria; Alfano, Brigida; Esposito, Elena; Francia, Girolamo Di

    2017-04-02

    The full exploitation of Composite Fiber Reinforced Polymers (CFRP) in so-called green aircrafts design is still limited by the lack of adequate quality assurance procedures for checking the adhesive bonding assembly, especially in load-critical primary structures. In this respect, contamination of the CFRP panel surface is of significant concern since it may severely affect the bonding and the mechanical properties of the joint. During the last years, the authors have developed and tested an electronic nose as a non-destructive tool for pre-bonding surface inspection for contaminants detection, identification and quantification. Several sensors and sampling architectures have been screened in view of the high Technology Readiness Level (TRL) scenarios requirements. Ad-hoc pattern recognition systems have also been devised to ensure a fast and reliable assessment of the contamination status, by combining real time classifiers and the implementation of a suitable rejection option. Results show that e-noses could be used as first line low cost Non Destructive Test (NDT) tool in aerospace CFRP assembly and maintenance scenarios.

  13. Characterization of sea surface chemical contamination after shipping accidents.

    Science.gov (United States)

    Guitart, Carlos; Frickers, Patricia; Horrillo-Caraballo, Jose; Law, Robin J; Readman, James W

    2008-04-01

    A contamination survey was conducted after the beaching of the stricken cargo ship MSC Napoli in Lyme Bay on the south coast of Devon (UK). A grid of 22 coastal and offshore stations was sampled to investigate the extent of spilled oil and to screen for chemical contamination, as well as to evaluate the behavior of the oil at the air-sea interface. Samples were collected from the sea surface microlayer (SML) and from subsurface waters (SSW) at each station. The fuel oil spilled (IFO 380) was also analyzed. The determination of oil-related hydrocarbons (aliphatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), terpanes, and steranes) and the screening for other harmful chemicals on the inventory of the MSC Napoli in the seawater samples, was performed by PTV-GC/ MS using large volume injection (LVI) techniques. Screening did not reveal the presence of any harmful chemicals other than petroleum-related compounds. Results afforded investigation of oil sources and spatial distributions of total PAH concentrations and enrichments in the sea surface microlayer (SML). Rather than a single source, oil fingerprinting analyses of the samples revealed a mixture of three types of oil: heavy fuel oil, lubricating oil, and a lighter oil (probably diesel oil). Enrichment factors (EF) in the SML (EF = C(SML)/C(SSW)) were calculated and, in the vicinity of the ship, approached 2000, declining with distance away from the wreck. These factors represent approximately a 1000-fold enrichment over typical coastal total PAH enrichments in the SML and reflected a clear petrogenic origin of the contamination (as demonstrated, for example, by a Fl/Pgamma ratio water column diffusion) of the oil-related hydrocarbons in the sea surface were investigated. Essentially, near the wreck, the SML was highly enriched in oil forming a visible sheen, both disrupting the normal air-seawater exchange processes and generating a downward diffusion flux of contaminants from the SML to the SSW. This

  14. Current levels and trends of radioactive contamination of aquatic ecosystem components in the Chernobyl exclusion zone

    Energy Technology Data Exchange (ETDEWEB)

    Gudkov, Dmitri I.; Kaglyan, Alexander Ye.; Ganzha, Kristina D.; Klenus, Vasiliy G. [Institute of Hydrobiology, Geroyev Stalingrada Ave. 12, UA-04210 Kiev (Ukraine); Kireev, Sergey I.; Nazarov, Alexander B. [Chernobyl Specialized Enterprise, Radyanska Str. 70, UA-07270 Chernobyl (Ukraine)

    2014-07-01

    The current radiation level and its composition in aquatic ecosystems within the Chernobyl exclusion zone (ChEZ) are conditioned, above all things, by the amount of radioactive matters released as aerosols on a water surface and adjacent territories during the period of the active phase of the accident from destroyed of the Chernobyl NPP in 1986, and also by intensity and duration of the second processes of radionuclides washout from the catchment areas and hydrodynamic processes of their transport outside of water bodies. During last 10-15 years in the soils of the ChEZ the tendency of increase of yield of the mobile bioavailable forms of radionuclides, which released into hydrological systems with surface and ground waters or localized in the closed water systems, where quickly involving in the biotic cycle is marked. On the example of lakes of the Krasnensky flood plain of the Pripyat River, which is one of the most contaminated by radionuclides territory of the ChEZ, was determined that the basic amount of radionuclides in lake ecosystem is deposited in the bottom sediments: {sup 90}Sr - 89-95%, {sup 137}Cs - 99%, transuranium elements (TUE) {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am - almost 100% of the total radionuclide amount in ecosystem. The increased migration activity of {sup 90}Sr determines its more high quantity in water (4-10%) on comparison with {sup 137}Cs (0.5-0.6%) and TUE (0.03-0.04%) and, opposite, less - in seston (0.15-0.16%) on comparison with {sup 137}Cs (0.25-0.30%). The value of {sup 90}Sr in biotic component amounts 0.25-0.61%, {sup 137}Cs - 0.14-0.47% and TUE - 0.07-0.16% of the total quantity in ecosystem. The gradual decline of radionuclide specific activity is a dominant tendency in the dynamics of {sup 137}Cs and {sup 90}Sr in water and aquatic biota of the majority of reservoirs and water flow in the ChEZ. The exception is water bodies, located on the dammed territories of the Krasnensky flood plain, where at the proceeding

  15. Averaging of diffusing contaminant concentrations in atmosphere surface layer

    International Nuclear Information System (INIS)

    Ivanov, E.A.; Ramzina, T.V.

    1985-01-01

    Calculations permitting to average concentration fields of diffusing radioactive contaminant coming from the NPP exhaust stack in the atmospheric surface layer are given. Formulae of contaminant concentration field calculation are presented; it depends on the average wind direction value (THETA) for time(T) and stability of this direction (σsub(tgTHETA) or σsub(THETA)). Probability of wind direction deviation from the average value for time T is satisfactory described by the Gauss law. With instability increase in the atmosphere σ increases, when wind velocity increasing the values of σ decreases for all types of temperature gradients. Nonuniformity of σ value dependence on averaging time T is underlined, that requires accurate choice of σsub(tgTHETA) and σsub(THETA) parameters in calculations

  16. Experimental study on source efficiencies for estimating surface contamination level

    International Nuclear Information System (INIS)

    Ichiji, Takeshi; Ogino, Haruyuki

    2008-01-01

    Source efficiency was measured experimentally for various materials, such as metals, nonmetals, flooring materials, sheet materials and other materials, contaminated by alpha and beta emitter radioactive nuclides. Five nuclides, 147 Pm, 60 Co, 137 Cs, 204 Tl and 90 Sr- 90 Y, were used as the beta emitters, and one nuclide 241 Am was used as the alpha emitter. The test samples were prepared by placing drops of the radioactive standardized solutions uniformly on the various materials using an automatic quantitative dispenser system from Musashi Engineering, Inc. After placing drops of the radioactive standardized solutions, the test materials were allowed to dry for more than 12 hours in a draft chamber with a hood. The radioactivity of each test material was about 30 Bq. Beta rays or alpha rays from the test materials were measured with a 2-pi gas flow proportional counter from Aloka Co., Ltd. The source efficiencies of the metals, nonmetals and sheet materials were higher than 0.5 in the case of contamination by the 137 Cs, 204 Tl and 90 Sr- 90 Y radioactive standardized solutions, higher than 0.4 in the case of contamination by the 60 Co radioactive standardized solution, and higher than 0.25 in the case of contamination by the alpha emitter the 241 Am radioactive standardized solution. These values were higher than those given in Japanese Industrial Standards (JIS) documents. In contrast, the source efficiencies of some permeable materials were lower than those given in JIS documents, because source efficiency varies depending on whether the materials or radioactive sources are wet or dry. This study provides basic data on source efficiency, which is useful for estimating the surface contamination level of materials. (author)

  17. An integrated model for assessing the risk of TCE groundwater contamination to human receptors and surface water ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Funder, S.G.; Rasmussen, J.J.

    2010-01-01

    The practical implementation of the European Water Framework Directive has resulted in an increased focus on the hyporheic zone. In this paper, an integrated model was developed for evaluating the impact of point sources in groundwater on human health and surface water ecosystems...... will not be depleted for many decades, however measured and predicted TCE concentrations in surface water were found to be below human health risk management targets. Volatilization rapidly attenuates TCE concentrations in surface water. Thus, only a 300 m stream reach fails to meet surface water quality criteria....... An ecological risk assessment found that the TCE contamination did not impact the stream ecosystem. Uncertainty assessment revealed hydraulic conductivity to be the most important site-specific parameter. These results indicate that contaminant plumes with μgL-1 concentrations of TCE entering surface water...

  18. Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone

    Energy Technology Data Exchange (ETDEWEB)

    Bonzom, Jean-Marc, E-mail: jean-marc.bonzom@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS, Cadarache, Bât. 183, BP 3, 13115 St Paul-lez-Durance (France); Hättenschwiler, Stephan [Centre d' Ecologie Fonctionnelle et Evolutive (CEFE UMR 5175, CNRS–Université de Montpellier–Université Paul-Valéry Montpellier–EPHE), 1919 Route de Mende, F-34293 Montpellier (France); Lecomte-Pradines, Catherine [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS, Cadarache, Bât. 183, BP 3, 13115 St Paul-lez-Durance (France); Chauvet, Eric [EcoLab, Université de Toulouse, CNRS, UPS, INPT, 118 Route de Narbonne, 31062 Toulouse cedex (France); Gaschak, Sergey [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); Beaugelin-Seiller, Karine; Della-Vedova, Claire; Dubourg, Nicolas [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS, Cadarache, Bât. 183, BP 3, 13115 St Paul-lez-Durance (France); Maksimenko, Andrey [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); and others

    2016-08-15

    The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely unknown. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the functioning of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black alder at (i) eleven distant forest sites differing in ambient radiation levels (0.22–15 μGy h{sup −1}) and (ii) along a short distance gradient of radioactive contamination (1.2–29 μGy h{sup −1}) within a single forest in the Chernobyl exclusion zone. In addition to measuring ambient external dose rates, we estimated the average total dose rates (ATDRs) absorbed by decomposers for an accurate estimate of dose-induced ecological consequences of radioactive pollution. Taking into account potential confounding factors (soil pH, moisture, texture, and organic carbon content), the results from the eleven distant forest sites, and from the single forest, showed increased litter mass loss with increasing ATDRs from 0.3 to 150 μGy h{sup −1}. This unexpected result may be due to (i) overcompensation of decomposer organisms exposed to radionuclides leading to a higher decomposer abundance (hormetic effect), and/or (ii) from preferred feeding by decomposers on the uncontaminated leaf litter used for our experiment compared to locally produced, contaminated leaf litter. Our data indicate that radio-contamination of forest ecosystems over more than two decades does not necessarily have detrimental effects on organic matter decay. However, further studies are needed to unravel the underlying mechanisms of the results reported here, in order to draw firmer conclusions on how radio-contamination affects decomposition and associated ecosystem processes. - Highlights: • The effects of radioactivity on

  19. Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone

    International Nuclear Information System (INIS)

    Bonzom, Jean-Marc; Hättenschwiler, Stephan; Lecomte-Pradines, Catherine; Chauvet, Eric; Gaschak, Sergey; Beaugelin-Seiller, Karine; Della-Vedova, Claire; Dubourg, Nicolas; Maksimenko, Andrey

    2016-01-01

    The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely unknown. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the functioning of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black alder at (i) eleven distant forest sites differing in ambient radiation levels (0.22–15 μGy h −1 ) and (ii) along a short distance gradient of radioactive contamination (1.2–29 μGy h −1 ) within a single forest in the Chernobyl exclusion zone. In addition to measuring ambient external dose rates, we estimated the average total dose rates (ATDRs) absorbed by decomposers for an accurate estimate of dose-induced ecological consequences of radioactive pollution. Taking into account potential confounding factors (soil pH, moisture, texture, and organic carbon content), the results from the eleven distant forest sites, and from the single forest, showed increased litter mass loss with increasing ATDRs from 0.3 to 150 μGy h −1 . This unexpected result may be due to (i) overcompensation of decomposer organisms exposed to radionuclides leading to a higher decomposer abundance (hormetic effect), and/or (ii) from preferred feeding by decomposers on the uncontaminated leaf litter used for our experiment compared to locally produced, contaminated leaf litter. Our data indicate that radio-contamination of forest ecosystems over more than two decades does not necessarily have detrimental effects on organic matter decay. However, further studies are needed to unravel the underlying mechanisms of the results reported here, in order to draw firmer conclusions on how radio-contamination affects decomposition and associated ecosystem processes. - Highlights: • The effects of radioactivity on ecosystem processes

  20. The effect of subsurface military detonations on vadose zone hydraulic conductivity, contaminant transport and aquifer recharge.

    Science.gov (United States)

    Lewis, Jeffrey; Burman, Jan; Edlund, Christina; Simonsson, Louise; Berglind, Rune; Leffler, Per; Qvarfort, Ulf; Thiboutot, Sonia; Ampleman, Guy; Meuken, Denise; Duvalois, Willem; Martel, Richard; Sjöström, Jan

    2013-03-01

    Live fire military training involves the detonation of explosive warheads on training ranges. The purpose of this experiment is to evaluate the hydrogeological changes to the vadose zone caused by military training with high explosive ammunition. In particular, this study investigates artillery ammunition which penetrates underground prior to exploding, either by design or by defective fuze mechanisms. A 105 mm artillery round was detonated 2.6 m underground, and hydraulic conductivity measurements were taken before and after the explosion. A total of 114 hydraulic conductivity measurements were obtained within a radius of 3m from the detonation point, at four different depths and at three different time periods separated by 18months. This data was used to produce a three dimensional numerical model of the soil affected by the exploding artillery round. This model was then used to investigate potential changes to aquifer recharge and contaminant transport caused by the detonating round. The results indicate that an exploding artillery round can strongly affect the hydraulic conductivity in the vadose zone, increasing it locally by over an order of magnitude. These variations, however, appear to cause relatively small changes to both local groundwater recharge and contaminant transport. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Modeling breathing-zone concentrations of airborne contaminants generated during compressed air spray painting.

    Science.gov (United States)

    Flynn, M R; Gatano, B L; McKernan, J L; Dunn, K H; Blazicko, B A; Carlton, G N

    1999-01-01

    This paper presents a mathematical model to predict breathing-zone concentrations of airborne contaminants generated during compressed air spray painting in cross-flow ventilated booths. The model focuses on characterizing the generation and transport of overspray mist. It extends previous work on conventional spray guns to include exposures generated by HVLP guns. Dimensional analysis and scale model wind-tunnel studies are employed using non-volatile oils, instead of paint, to produce empirical equations for estimating exposure to total mass. Results indicate that a dimensionless breathing zone concentration is a nonlinear function of the ratio of momentum flux of air from the spray gun to the momentum flux of air passing through the projected area of the worker's body. The orientation of the spraying operation within the booth is also very significant. The exposure model requires an estimate of the contaminant generation rate, which is approximated by a simple impactor model. The results represent an initial step in the construction of more realistic models capable of predicting exposure as a mathematical function of the governing parameters.

  2. Secondary contamination of 30-km zone of the Chernobyl atomic electric plant and adjacent territory due to radionuclides carried by ascending wind

    International Nuclear Information System (INIS)

    Garger, E.K.; Gavrilov, V.P.

    1992-01-01

    The territory contaminated with radionuclides as a result of the accident at the Chernobyl atomic electric plant is a surface source of radioactive aerosols carried into the atmosphere by ascending winds. In this connection, a number of problems arise whose solution is important for assessment of the radiation conditions in the atmosphere near the Earth's surface: (1) calculation of the volume concentration of radionuclides and their fallout on the contaminated and neighboring territory and on this basis determine the potentially dangerous contaminated regions; (2) assessment of the secondary contamination of deactivated territories due to ascending winds and transfer of radionuclides; and (3) determination of the size of the protective (buffer) zones around or near populated areas to ensure low volume concentrations of radionuclides during strong winds. In order to calculate the transfer of radionuclides from a surface source, it is necessary to know its dust intensity, which is the vertical turbulent flux of the radionuclides in the atmosphere layer near the ground Q (Ci · m -2 sec -1 ). A quantity frequently used in practice is Q referred to the contamination density of the surface layer c (Ci/m 2 ) and called the wind ascent intensity α = Q/c. As a rule, the radionuclide wind ascent intensity for a plane source with a nonuniform surface and contamination density may depend on the physical characteristics of the surface as well as on those of the radionuclides and also on the space coordinates x, y and on time. In the present study, the wind ascent intensity was determined by gradient measurements of the mean radionuclide concentration, the wind velocity and air temperature; the conditions during the measurements were assumed to correspond to the case of a plane homogeneous, stationary source of a nondepositing admixture

  3. Use of stable carbon isotope analysis to assess natural attenuation of organic contaminants in the unsaturated zone

    International Nuclear Information System (INIS)

    Bouchard, D.; Hunkeler, D.; Aravena, R.; Kjeldsen, P.; Gaganis, P.; Hohener, P.

    2005-01-01

    Introduction Natural attenuation is an attractive remediation strategy when dealing with petroleum-hydrocarbon contaminated sites because of its cost efficiency. The unsaturated zone can play an important role in regulating the contaminant transfer between soil and groundwater. On one hand, contaminants from the soil zone may be degraded in the unsaturated zone thus preventing groundwater contamination. On the other hand, contaminants diffusing from the subsurface towards the atmosphere may be eliminated before reaching potential targets. Biodegradation is usually the main process leading to contaminant destruction and is usually considered to be the only process to influence 13 C/ 12 C ratio of organic contaminants in the saturated zone. Therefore, carbon and hydrogen isotope analysis has been used as a tool to demonstrate biodegradation (Griebler et al. 2004, Steinbach et al. 2004). Carbon and hydrogen isotope fractionation occurs during biodegradation as a consequence of the slightly faster cleavage of chemical bonds between light isotopes of an element compared to heavy isotopes. The difference in degradation rates leads to an enrichment of the heavy isotopes in the residual contaminant pool compared to the initial value. Most of the field studies focused on the saturated zone (Meckenstock et al. 2004) compare to only few studies on the unsaturated zone (Kirtland et al. 2005, Stehmeier et al. 1999). The aim of this study was to evaluate whether compound-specific stable isotope analysis can be used to demonstrate biodegradation of petroleum hydrocarbons in the unsaturated zone. The study included a field experiment and mathematical simulations. At the field site, a defined mixture of hydrocarbons was buried in a sandy unsaturated zone and the evolution of concentration and isotope ratios of various hydrocarbons was followed using a dense network of sampling points. The study was complemented with two mathematical simulations performed to gain insight into the

  4. Metal contamination of agricultural soils in the copper mining areas of Singhbhum shear zone in India

    Science.gov (United States)

    Giri, Soma; Singh, Abhay Kumar; Mahato, Mukesh Kumar

    2017-06-01

    The study was intended to investigate the heavy metal contamination in the agricultural soils of the copper mining areas in Singhbhum shear zone, India. The total concentrations of the metals were determined by inductively coupled plasma-mass spectrometer (ICPMS). Pollution levels were assessed by calculating enrichment factor (EF), geo-accumulation index (I_geo), contamination factors (CF), pollution load index ( PLI), Nemerow index and ecological risk index (RI). The metal concentrations in the soil samples exceeded the average shale values for almost all the metals. Principal component analysis resulted in extraction of three factors explaining 82.6% of the data variability and indicated anthropogenic contribution of Cu, Ni, Co, Cr, Mn and Pb. The EF and I_geo values indicated very high contamination with respect to Cu followed by As and Zn in the agricultural soils. The values of PLI, RI and Nemerow index, which considered the overall effect of all the studied metals on the soils, revealed that 50% of the locations were highly polluted with respect to metals. The pollution levels varied with the proximity to the copper mining and processing units. Consequently, the results advocate the necessity of periodic monitoring of the agricultural soils of the area and development of proper management strategies to reduce the metal pollution.

  5. An integrated model for assessing the risk of TCE groundwater contamination to human receptors and surface water ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Funder, S.G.; Rasmussen, J.J.

    2010-01-01

    The practical implementation of the European Water Framework Directive has resulted in an increased focus on the hyporheic zone. In this paper, an integrated model was developed for evaluating the impact of point sources in groundwater on human health and surface water ecosystems....... An ecological risk assessment found that the TCE contamination did not impact the stream ecosystem. Uncertainty assessment revealed hydraulic conductivity to be the most important site-specific parameter. These results indicate that contaminant plumes with μgL-1 concentrations of TCE entering surface water....... This was accomplished by coupling the system dynamics-based decision support system CARO-PLUS to the aquatic ecosystem model AQUATOX using an analytical volatilization model for the stream. The model was applied to a case study where a TCE contaminated groundwater plume is discharging to a stream. The TCE source...

  6. Bacteria contamination of touch surfaces in Polish hospital wards

    Directory of Open Access Journals (Sweden)

    Anna Różańska

    2017-08-01

    Full Text Available Background: The objective of the study has been to evaluate the pathogenic bacteria contamination of touch surfaces in hospital wards. Material and Methods: Samples were taken from frequently touched surfaces in the hospital environment in 13 units of various types. Culturing was carried out on solid blood agar and in growth broth (tryptic soy broth – TSB. Species identification was performed using the analytical profile index (API biochemical testing and confirmed with matrix assisted laser desorption ionization time-flight mass spectrometry (MALDI-TOF-MS system. Results: The total of 161 samples were taken for the study. Fifty-two of them, after 24 h of culture on a solid medium, demonstrated bacterial growth and further 60 samples had growth after prior multiplication in TSB. Overall, 69.6% of samples exhibited growth of 19 bacterial species. Pathogenic species – representing indicator organisms of efficiency of hospital cleaning – was demonstrated by 21.4% of samples. Among them Acinetobacter spp., Enterocococci spp. and Staphylococcus aureus were identified. Coagulase-negative staphylococci (CNS were predominant. The proportion of various groups of bacteria significantly varied in respective hospitals, and in various types of wards. Disturbing observation is a large proportion of resistance of isolated CNS strains as a potential reservoir of resistance genes. Conclusions: The results show that touch surfaces in hospital units are contaminated by both potentially pathogenic and pathogenic bacterial species. In connection with the reported, also in Poland, frequent omission or incorrect execution of hand hygiene by hospital staff, and probably patients, touch surfaces still constitute important reservoir of pathogenic bacteria. Improving hand hygiene compliance of health-care workers with recommendations is necessary for increasing biological safety of hospital environment. Med Pr 2017;68(3:459–467

  7. Quantifying the spatial variability in critical zone architecture through surface mapping and near-surface geophysics

    Science.gov (United States)

    DiBiase, R.; Del Vecchio, J.; Mount, G.; Hayes, J. L.; Comas, X.; Guo, L.; Lin, H.; Zarif, F.; Forsythe, B.; Brantley, S. L.

    2016-12-01

    The composition and structure of Earth's surface and shallow subsurface control the flux of water, solutes, and sediment from hillslopes into rivers. Additionally, bedrock weathering profiles and the stratigraphy of soil and colluvium preserve a record of past surface processes. However, landscapes often exhibit heterogeneity in critical zone architecture that is difficult to capture with remote sensing and costly to characterize through direct measurement in soil pits or drill cores. Here we present results from a multifaceted approach to quantifying spatial variability in critical zone architecture using airborne lidar topography, surface mapping, and a suite of geophysical surveys. We focus on Garner Run, a first order sandstone catchment in the Susquehanna Shale Hills Critical Zone Observatory situated in the valley and ridge province of central Pennsylvania, 80 km southwest of the last glacial maximum ice limit. Results from lidar topographic analysis and detailed mapping of surface cover (e.g., soil versus boulder-mantled) reveal a pattern of relict periglacial landforms and deposits that vary depending on slope position and aspect. Additionally, a drill core taken from an unchanneled valley at the head of Garner Run indicates at least 9 meters of alternating sand- and boulder-rich colluvial fill sourced from adjacent hillslopes, indicating the potential preservation of multiple cycles of periglacial climate conditions. Through the use of shallow geophysical techniques, including cross-valley transects of seismic refraction, multiple frequency ground-penetrating radar (GPR), and electrical resistivity tomography (ERT), we image spatial patterns in subsurface architecture at a range of scales (10-1,000 m), and high spatial resolution (cm). Notably, despite challenging environmental conditions, there is agreement among diverse subsurface methods in highlighting aspect-dependent controls on weathering zone thickness that furthermore can be directly connected to

  8. Imbalance in Groundwater-Surface Water Interactions and its Relationship to the Coastal Zone Hazards

    Science.gov (United States)

    Kontar, Y. A.; Ozorovich, Y. R.; Salokhiddinov, A. T.

    2011-12-01

    to their intensive pollution by industrial wastes and by drainage waters from irrigated fields, the Syr Darya and Amu Darya rivers can no longer be considered as a source of safe and sustainable water supply. In such a situation, a number of scientists consider that the population's water supply must be achieved through a more comprehensive use of fresh and even subsaline groundwater resources from the coastal aquifers. The 2004 tsunami in the Indian Ocean caused imbalance in groundwater-surface water interactions and a disaster affecting thousands of kilometers of coastal zone in SE Asia. Many coastal wetlands were affected in the short term by the large inflow of salt seawater and littoral sediment deposited during the tsunami, and in the longer-term by changes in their hydrogeology caused by changes to coastlines and damage to sea-defenses. Many water quality and associated problems were generated by the tsunami. The tsunami has created imbalance in groundwater-surface water interactions and an accelerating process of salt-water intrusion and fresh-water contaminations in affected regions that now require drastic remediation measures.

  9. T Tank Farm Interim Surface Barrier Demonstration--Vadose Zone Monitoring Plan

    International Nuclear Information System (INIS)

    Zhang, Z. F.; Keller, Jason M.; Strickland, Christopher E.

    2007-01-01

    The Hanford Site has 149 underground single-shell tanks that store hazardous radioactive waste. Many of these tanks and their associated infrastructure (e.g., pipelines, diversion boxes) have leaked. Some of the leaked waste has entered the groundwater. The largest known leak occurred from the T-106 Tank in 1973. Many of the contaminants from that leak still reside within the vadose zone beneath the T Tank Farm. CH2M Hill Hanford Group, Inc. seeks to minimize movement of this residual contaminant plume by placing an interim barrier on the surface. Such a barrier is expected to prevent infiltrating water from reaching the plume and moving it further. A plan has been prepared to monitor and determine the effectiveness of the interim surface barrier. Soil water content and water pressure will be monitored using off-the-shelf equipment that can be installed by the hydraulic hammer technique. In fiscal year 2006, two instrument nests were installed. Each instrument nest contains a neutron probe access tube, a capacitance probe, four heat-dissipation units, and a drain gauge to measure soil water flux. A meteorological station has been installed outside of the fence. In fiscal year 2007, two additional instrument nests are planned to be installed beneath the proposed barrier.

  10. T Tank Farm Interim Surface Barrier Demonstration--Vadose Zone Monitoring Plan

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z. F.; Keller, Jason M.; Strickland, Christopher E.

    2007-04-01

    The Hanford Site has 149 underground single-shell tanks that store hazardous radioactive waste. Many of these tanks and their associated infrastructure (e.g., pipelines, diversion boxes) have leaked. Some of the leaked waste has entered the groundwater. The largest known leak occurred from the T-106 Tank in 1973. Many of the contaminants from that leak still reside within the vadose zone beneath the T Tank Farm. CH2M Hill Hanford Group, Inc. seeks to minimize movement of this residual contaminant plume by placing an interim barrier on the surface. Such a barrier is expected to prevent infiltrating water from reaching the plume and moving it further. A plan has been prepared to monitor and determine the effectiveness of the interim surface barrier. Soil water content and water pressure will be monitored using off-the-shelf equipment that can be installed by the hydraulic hammer technique. In fiscal year 2006, two instrument nests were installed. Each instrument nest contains a neutron probe access tube, a capacitance probe, four heat-dissipation units, and a drain gauge to measure soil water flux. A meteorological station has been installed outside of the fence. In fiscal year 2007, two additional instrument nests are planned to be installed beneath the proposed barrier.

  11. Drainage-water travel times as a key factor for surface water contamination

    NARCIS (Netherlands)

    Groenendijk, P.; Eertwegh, van den G.A.P.H.

    2004-01-01

    The importance of the unsaturated zone as an inextricable part of the hydrologic cycle has long been recognized. The root zone and the unsaturated sub-surface domain are chemically and biologically the most active zones. The interrelationships between soil, subsoil and surface waters make it

  12. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    OpenAIRE

    Furuse, Adilson Yoshio; Cunha, Leonardo Fernandes da; Benetti, Ana Raquel; Mondelli, José

    2007-01-01

    The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1) rinsing with water and drying; (G2) application of an adhesive system; (G3) rinsing and drying, abrasion wit...

  13. T-TY Tank Farm Interim Surface Barrier Demonstration—Vadose Zone Monitoring Plan

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z. F.; Strickland, Christopher E.; Field, Jim G.; Parker, Danny L.

    2010-09-27

    The Hanford Site has 149 underground single-shell tanks that store hazardous radioactive waste. Many of these tanks and their associated infrastructure (e.g., pipelines, diversion boxes) have leaked. Some of the leaked waste has entered the groundwater. The largest known leak occurred from the T-106 Tank of the 241-T Tank Farm in 1973. Five tanks are assumed to have leaked in the TY Farm. Many of the contaminants from those leaks still reside within the vadose zone within the T and TY Tank Farms. The Department of Energy’s Office of River Protection seeks to minimize the movement of these contaminant plumes by placing interim barriers on the ground surface. Such barriers are expected to prevent infiltrating water from reaching the plumes and moving them further. The soil water regime is monitored to determine the effectiveness of the interim surface barriers. Soil-water content and water pressure are monitored using off-the-shelf equipment that can be installed by the hydraulic hammer technique. Four instrument nests were installed in the T Farm in fiscal year (FY) 2006 and FY2007; two nests were installed in the TY Farm in FY2010. Each instrument nest contains a neutron probe access tube, a capacitance probe, and four heat-dissipation units. A meteorological station has been installed at the north side of the fence of the T Farm. This document summarizes the monitoring methods, the instrument calibration and installation, and the vadose zone monitoring plan for interim barriers in T farm and TY Farm.

  14. T-TY Tank Farm Interim Surface Barrier Demonstration - Vadose Zone Monitoring Plan

    International Nuclear Information System (INIS)

    Zhang, Z.F.; Strickland, Christopher E.; Field, Jim G.; Parker, Danny L.

    2010-01-01

    The Hanford Site has 149 underground single-shell tanks that store hazardous radioactive waste. Many of these tanks and their associated infrastructure (e.g., pipelines, diversion boxes) have leaked. Some of the leaked waste has entered the groundwater. The largest known leak occurred from the T-106 Tank of the 241-T Tank Farm in 1973. Five tanks are assumed to have leaked in the TY Farm. Many of the contaminants from those leaks still reside within the vadose zone within the T and TY Tank Farms. The Department of Energy's Office of River Protection seeks to minimize the movement of these contaminant plumes by placing interim barriers on the ground surface. Such barriers are expected to prevent infiltrating water from reaching the plumes and moving them further. The soil water regime is monitored to determine the effectiveness of the interim surface barriers. Soil-water content and water pressure are monitored using off-the-shelf equipment that can be installed by the hydraulic hammer technique. Four instrument nests were installed in the T Farm in fiscal year (FY) 2006 and FY2007; two nests were installed in the TY Farm in FY2010. Each instrument nest contains a neutron probe access tube, a capacitance probe, and four heat-dissipation units. A meteorological station has been installed at the north side of the fence of the T Farm. This document summarizes the monitoring methods, the instrument calibration and installation, and the vadose zone monitoring plan for interim barriers in T farm and TY Farm.

  15. Effect of Surface Contaminants Remained on the Blasted Surface on Epoxy Coating Performance and Corrosion Resistance

    International Nuclear Information System (INIS)

    Baek, Kwang Ki; Park, Chung Seo; Kim, Ki Hong; Chung, Mong Kyu; Park, Jin Hwan

    2006-01-01

    One of the critical issues in the coating specification is the allowable limit of surface contaminant(s) - such as soluble salt(s), grit dust, and rust - after grit blasting. Yet, there is no universally accepted data supporting the relationship between the long-term coating performance and the amount of various surface contaminants allowed after grit blasting. In this study, it was attempted to prepare epoxy coatings applied on grit-blasted steel substrate dosed with controlled amount of surface contaminants - such as soluble salt(s), grit dust, and rust. Then, coating samples were subjected to 4,200 hours of cyclic test(NORSOK M-501), which were then evaluated in terms of resistance to rust creepage, blistering, chalking, rusting, cracking and adhesion strength. Additional investigations on the possible damage at the paint/steel interface were carried out using an Electrochemical Impedance Spectroscopy(EIS) and observations of under-film-corrosion. Test results suggested that the current industrial specifications were well matched with the allowable degree of rust, whereas the allowable amount of soluble salt and grit dust after grit blasting showed a certain deviation from the specifications currently employed for fabrication of marine vessels and offshore facilities

  16. Features of emotional sphere of the teachers working in a zone of radiation contamination

    International Nuclear Information System (INIS)

    Zajtsev, V.A.; Evdokimova, O.M.; Kopteva, S.I.; Rozhina, L.N.; Slepkova, V.I.

    1995-01-01

    Availability of negative changes in the development of emotional sphere of teenagers has allowed to assume, that the teachers, working with the surveyed schoolboys, have similar problems. For check of this hypothesis were investigated both the emotional world of the base schools teachers and understanding by the teachers of a pedagogic of the contents of the schoolboys emotional experiences. The features of emotional sphere of the teachers working in conditions of increased radiation, are displayed in a high level of a situational and personal alarm worrying, decrease of activity of a mood, deterioration of a general condition, strengthening of asthenia emotions. The found out changes are displayed stronger at those teachers, which live on territory with a higher level of radiation contamination. A necessity of rendering of a psychological aid for the teachers working at an a zone of the Chernobyl NPP accident is shown

  17. Surface modification by preparation of buffer zone in glow-discharge plasma

    International Nuclear Information System (INIS)

    Cho, D.L.

    1986-01-01

    Reactive species, energetic particles, and uv radiation in the plasma created by a glow discharge strongly interact with solid surfaces under the influence of the plasma. As a result of the strong interaction, various physical and chemical reactions, unique and advantageous for the surface modification of solid materials, occur on the solid surfaces. The surface modification is carried out through formation of a thin buffering layer on the solid surface. The preparation of a buffer zone on solid surfaces for surface modification is described. Two kinds of a buffer zone are prepared by plasma polymerization, or simultaneous sputter deposition of electrode material with plasma polymerization: a transitional buffer zone and a graded buffer zone. Important factors for preparation of the buffer zone (pre-conditioning of a substrate surface, thin-film deposition, post-treatment of the film, magnetron discharge, energy input, geometry of a substrate and a plasma) are discussed

  18. Fracture zones constrained by neutral surfaces in a fault-related fold: Insights from the Kelasu tectonic zone, Kuqa Depression

    Science.gov (United States)

    Sun, Shuai; Hou, Guiting; Zheng, Chunfang

    2017-11-01

    Stress variation associated with folding is one of the controlling factors in the development of tectonic fractures, however, little attention has been paid to the influence of neutral surfaces during folding on fracture distribution in a fault-related fold. In this study, we take the Cretaceous Bashijiqike Formation in the Kuqa Depression as an example and analyze the distribution of tectonic fractures in fault-related folds by core observation and logging data analysis. Three fracture zones are identified in a fault-related fold: a tensile zone, a transition zone and a compressive zone, which may be constrained by two neutral surfaces of fold. Well correlation reveals that the tensile zone and the transition zone reach the maximum thickness at the fold hinge and get thinner in the fold limbs. A 2D viscoelastic stress field model of a fault-related fold was constructed to further investigate the mechanism of fracturing. Statistical and numerical analysis reveal that the tensile zone and the transition zone become thicker with decreasing interlimb angle. Stress variation associated with folding is the first level of control over the general pattern of fracture distribution while faulting is a secondary control over the development of local fractures in a fault-related fold.

  19. A consideration on internal dose evaluation and intervention based on a surface contamination concept

    International Nuclear Information System (INIS)

    Yasuda, H.

    1997-01-01

    Long-term radiation doses received by the inhabitants after the Chernobyl accident have been evaluated according to the surface contamination levels on the ground surface. The health effects have also been discussed by comparison between the surface-contaminated area and the uncontaminated control area. Selected protective measures were carried out in accordance with the contamination level of surface soil. These have been based on the 'surface contamination concept' which assumes that the radiation risk to inhabitants is proportional to the level of ground-surface contamination. The observations collected in regions around Chernobyl, however, show that the internal radiation doses to the inhabitants poorly correlate with the surface contamination level. This fact poses a question on the suitability of dose evaluations and interventions based on this concept

  20. Chaotic-dynamical conceptual model to describe fluid flow and contaminant transport in a fractured vadose zone. 1998 annual progress report

    International Nuclear Information System (INIS)

    Doughty, C.; Dragila, M.I.; Faybishenko, B.; Podgorney, R.K.; Stoops, T.M.; Wheatcraft, S.W.; Wood, T.R.

    1998-01-01

    'DOE faces the remediation of numerous contaminated sites, such as those at Hanford, INEEL, LLNL, and LBNL, where organic and/or radioactive wastes were intentionally or accidentally released to the vadose zone from surface spills, underground tanks, cribs, shallow ponds, and deep wells. Migration of these contaminants through the vadose zone has lead to the contamination of or threatens to contaminate underlying groundwater. A key issue in choosing a corrective action plan to clean up contaminated sites is to determine the location, total mass, mobility and travel time to receptors for contaminants moving in the vadose zone. These problems are difficult to solve in a technically defensible and accurate manner because contaminants travel downward intermittently through narrow pathways driven by variations in environmental conditions. These preferential pathways can be difficult to find and predict. The primary objective of this project is to determine if and when dynamical chaos theory can be used to investigate infiltration of fluid and contaminant transport in heterogeneous soils and fractured rocks. The objective of this project is being achieved through the following Activities (1) Evaluation of chaotic behavior of flow in laboratory and field experiments using methods from non-linear dynamics; (2) Evaluation of the impact these dynamics may have on contaminant transport through heterogeneous fractured rocks and soils, and how it can be used to guide remediation efforts; (3) Development of a conceptual model and mathematical and numerical algorithms for flow and transport, which incorporate both: (a) the spatial variability of heterogeneous porous and fractured media, and (b) the description of the temporal dynamics of flow and transport, which may be chaotic; and (4) Development of appropriate experimental field and laboratory techniques needed to detect diagnostic parameters for chaotic behavior of flow. This approach is based on the assumption that spatial

  1. Using artificial sweeteners to identify contamination sources and infiltration zones in a coupled river-aquifer system

    Science.gov (United States)

    Bichler, Andrea; Muellegger, Christian; Hofmann, Thilo

    2014-05-01

    In shallow or unconfined aquifers the infiltration of contaminated river water might be a major threat to groundwater quality. Thus, the identification of possible contamination sources in coupled surface- and groundwater systems is of paramount importance to ensure water quality. Micropollutants like artificial sweeteners are promising markers for domestic waste water in natural water bodies. Compounds, such as artificial sweeteners, might enter the aquatic environment via discharge of waste water treatment plants, leaky sewer systems or septic tanks and are ubiquitously found in waste water receiving waters. The hereby presented field study aims at the (1) identification of contamination sources and (2) delineation of infiltration zones in a connected river-aquifer system. River bank filtrate in the groundwater body was assessed qualitatively and quantitatively using a combined approach of hydrochemical analysis and artificial sweeteners (acesulfame ACE) as waste water markers. The investigated aquifer lies within a mesoscale alpine head water catchment and is used for drinking water production. It is hypothesized that a large proportion of the groundwater flux originates from bank filtrate of a nearby losing stream. Water sampling campaigns in March and July 2012 confirmed the occurrence of artificial sweeteners at the investigated site. The municipal waste water treatment plant was identified as point-source for ACE in the river network. In the aquifer ACE was present in more than 80% of the monitoring wells. In addition, water samples were classified according to their hydrochemical composition, identifying two predominant types of water in the aquifer: (1) groundwater influenced by bank filtrate and (2) groundwater originating from local recharge. In combination with ACE concentrations a third type of water could be discriminated: (3) groundwater influence by bank filtrate but infiltrated prior to the waste water treatment plant. Moreover, the presence of ACE

  2. Spatial datasets of radionuclide contamination in the Ukrainian Chernobyl Exclusion Zone

    Science.gov (United States)

    Kashparov, Valery; Levchuk, Sviatoslav; Zhurba, Marina; Protsak, Valentyn; Khomutinin, Yuri; Beresford, Nicholas A.; Chaplow, Jacqueline S.

    2018-02-01

    The dataset Spatial datasets of radionuclide contamination in the Ukrainian Chernobyl Exclusion Zone was developed to enable data collected between May 1986 (immediately after Chernobyl) and 2014 by the Ukrainian Institute of Agricultural Radiology (UIAR) after the Chernobyl accident to be made publicly available. The dataset includes results from comprehensive soil sampling across the Chernobyl Exclusion Zone (CEZ). Analyses include radiocaesium (134Cs and 134Cs) 90Sr, 154Eu and soil property data; plutonium isotope activity concentrations in soil (including distribution in the soil profile); analyses of hot (or fuel) particles from the CEZ (data from Poland and across Europe are also included); and results of monitoring in the Ivankov district, a region adjacent to the exclusion zone. The purpose of this paper is to describe the available data and methodology used to obtain them. The data will be valuable to those conducting studies within the CEZ in a number of ways, for instance (i) for helping to perform robust exposure estimates to wildlife, (ii) for predicting comparative activity concentrations of different key radionuclides, (iii) for providing a baseline against which future surveys in the CEZ can be compared, (iv) as a source of information on the behaviour of fuel particles (FPs), (v) for performing retrospective dose assessments and (vi) for assessing natural background dose rates in the CEZ. The CEZ has been proposed as a radioecological observatory (i.e. a radioactively contaminated site that will provide a focus for long-term, radioecological collaborative international research). Key to the future success of this concept is open access to data for the CEZ. The data presented here are a first step in this process. The data and supporting documentation are freely available from the Environmental Information Data Centre (EIDC) under the terms and conditions of the Open Government Licence: https://doi.org/10.5285/782ec845-2135-4698-8881-b38823e533bf

  3. Spatial datasets of radionuclide contamination in the Ukrainian Chernobyl Exclusion Zone

    Directory of Open Access Journals (Sweden)

    V. Kashparov

    2018-02-01

    Full Text Available The dataset Spatial datasets of radionuclide contamination in the Ukrainian Chernobyl Exclusion Zone was developed to enable data collected between May 1986 (immediately after Chernobyl and 2014 by the Ukrainian Institute of Agricultural Radiology (UIAR after the Chernobyl accident to be made publicly available. The dataset includes results from comprehensive soil sampling across the Chernobyl Exclusion Zone (CEZ. Analyses include radiocaesium (134Cs and 134Cs 90Sr, 154Eu and soil property data; plutonium isotope activity concentrations in soil (including distribution in the soil profile; analyses of hot (or fuel particles from the CEZ (data from Poland and across Europe are also included; and results of monitoring in the Ivankov district, a region adjacent to the exclusion zone. The purpose of this paper is to describe the available data and methodology used to obtain them. The data will be valuable to those conducting studies within the CEZ in a number of ways, for instance (i for helping to perform robust exposure estimates to wildlife, (ii for predicting comparative activity concentrations of different key radionuclides, (iii for providing a baseline against which future surveys in the CEZ can be compared, (iv as a source of information on the behaviour of fuel particles (FPs, (v for performing retrospective dose assessments and (vi for assessing natural background dose rates in the CEZ. The CEZ has been proposed as a radioecological observatory (i.e. a radioactively contaminated site that will provide a focus for long-term, radioecological collaborative international research. Key to the future success of this concept is open access to data for the CEZ. The data presented here are a first step in this process. The data and supporting documentation are freely available from the Environmental Information Data Centre (EIDC under the terms and conditions of the Open Government Licence: https://doi.org/10.5285/782ec845-2135-4698-8881-b

  4. A convenient method for estimating the contaminated zone of a subsurface aquifer resulting from radioactive waste disposal into ground

    International Nuclear Information System (INIS)

    Fukui, Masami; Katsurayama, Kousuke; Uchida, Shigeo.

    1981-01-01

    Studies were conducted to estimate the contamination spread resulting from the radioactive waste disposal into a subsurface aquifer. A general equation, expressing the contaminated zone as a function of radioactive decay, the physical and chemical parameters of soil is presented. A distribution coefficient was also formulated which can be used to judge the suitability of a site for waste disposal. Moreover, a method for predicting contaminant concentration in groundwater at a site boundary is suggested for a heterogeneous media where the subsurface aquifer has different values of porosity, density, flow velocity, distribution coefficient and so on. A general equation was also developed to predict the distribution of radionuclides resulting from the disposal of a solid waste material. The distributions of contamination was evaluated for 90 Sr and 239 Pu which obey a linear adsorption model and a first order kinetics respectively. These equations appear to have practical utility for easily estimating groundwater contamination. (author)

  5. Arsenic transport between surface and groundwater in a moderately reducing zone: Geochemical approach

    Science.gov (United States)

    Khaska, Mahmoud; Le Gal La Salle, Corinne; Verdoux, Patrick

    2015-04-01

    Arsenic contamination represents a major risk to human health as one of the most prominent environmental causes of cancer mortality. Mining activities, particularly those involving arsenic rich ores have an impact on the environment and on human health that may persist for many decades after mine closure. The relationships between As released from alluvial aquifer in the vicinity of the sulfide-rich mine dumps was demonstrated with geochemical and isotopic tracers (major and traces elements, 87Sr/86Sr, 18O, 2H). Strontium isotopes were used to trace the transport of As downstream from a As rich tailing dam. Increasing As and Fe concentrations in surface water are explained by As release associated with alluvial groundwater discharge to the stream. This process occurs in a moderately reduced section of the stream downgradient from the sulfide-rich tailing dam. High As, total Fe and low Eh in groundwater confirm the discharge of alluvial groundwater and explain its impact on surface water. Transport of As between surface and groundwater can be described as follows: 1- Subsurface moderately reducing conditions prevail in groundwater downgradient from the tailing dams. This suggests a flux of reduced water from sulfide-rich tailing dams which is characterized by its high As and Fe content resulting from the reduction of Fe-sulfides. 2- Upon mixing with surface water, oxidizing conditions prevails and precipitate as Fe hydroxide on the stream bed. As and Sr subsequently adsorbed on the Fe -oxyhydroxide surface. This process contributes to the immobilization of As in surface water. Remaining dissolved As in surface water can be re-introduced in alluvial groundwater downstream of the reducing zone.

  6. DEEP VADOSE ZONE CONTAMINATION DUE TO RELEASES FROM HANFORD SITE TANKS

    International Nuclear Information System (INIS)

    JARAYSI MN

    2008-01-01

    CH2M HILL Hanford Group, Inc. (the Hanford Tank Farm Operations contractor) and the Department of Energy's Office of River Protection have just completed the first phase of the Hanford Single-Shell Tank RCRA Corrective Action Program. The focus of this first phase was to characterize the nature and extent of past Hanford single-shell tank releases and to characterize the resulting fate and transport of the released contaminants. Most of these plumes are below 20 meters, with some reaching groundwater (at 60 to 120 meters below ground surface [bgs])

  7. Surface Contamination Monitor and Survey Information Management System

    International Nuclear Information System (INIS)

    1998-02-01

    Shonka Research Associates, Inc.'s (SRA) Surface Contamination Monitor and Survey Information management System (SCM/SIMS) is designed to perform alpha and beta radiation surveys of floors and surfaces and document the measured data. The SRA-SCM/SIMS technology can be applied to routine operational surveys, characterization surveys, and free release and site closure surveys. Any large nuclear site can make use of this technology. This report describes a demonstration of the SRA-SCM/SIMS technology. This demonstration is part of the chicago Pile-5 (CP-5) Large-Scale Demonstration Project (LSDP) sponsored by the US Department of Energy (DOE), Office of Science and Technology (ST), Deactivation and Decommissioning Focus Area (DDFA). The objective of the LSDP is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East's (ANL) CP-5 Research Reactor Facility. The purpose of the LSDP is to demonstrate that by using innovative and improved deactivation and decommissioning (D and D) technologies from various sources, significant benefits can be achieved when compared to baseline D and D technologies

  8. Surface Contamination Monitor and Survey Information Management System

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    Shonka Research Associates, Inc.`s (SRA) Surface Contamination Monitor and Survey Information management System (SCM/SIMS) is designed to perform alpha and beta radiation surveys of floors and surfaces and document the measured data. The SRA-SCM/SIMS technology can be applied to routine operational surveys, characterization surveys, and free release and site closure surveys. Any large nuclear site can make use of this technology. This report describes a demonstration of the SRA-SCM/SIMS technology. This demonstration is part of the chicago Pile-5 (CP-5) Large-Scale Demonstration Project (LSDP) sponsored by the US Department of Energy (DOE), Office of Science and Technology (ST), Deactivation and Decommissioning Focus Area (DDFA). The objective of the LSDP is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East`s (ANL) CP-5 Research Reactor Facility. The purpose of the LSDP is to demonstrate that by using innovative and improved deactivation and decommissioning (D and D) technologies from various sources, significant benefits can be achieved when compared to baseline D and D technologies.

  9. Uptake of americium-241 by plants from contaminated Chernobyl exclusive zone test site soils

    International Nuclear Information System (INIS)

    Rashydov, N.M.

    2002-01-01

    Americium-241 was found to accumulate in soils and biological objects of the environment. Its concentration has increased many times after the Chernobyl disaster and can be expected to increase about 40 times in the future. This research concentrated on the contaminated exclusive Chernobyl zone polluted by trace radionuclides, their behavior and accumulation by various plant species. Special attention is devoted to the bioavailability of 241 Am to the plants Galium rivale, G. tinctorium, G. aparine, G. intermedium, Berteroa incana, Artemisia absinthium, A. vulgaris, Centaurea borysthenica, C. arenaria, Cirsium arvense, Succissa pratensis, Solidago virgaurea, Linaria vulgaris, Lepidium ruderale, Stenactis annua, Veronica maxima, Verbascum lychnitis, Euphorbia cyparissias, Genista tinctoria, Erigeron canadensis, Oenothera biennis, Betula pendula and Quercus robur, which were collected from the Chernobyl, Kopachi, and Yanov districts. The plant samples of Oenothera biennis, Betula pendula and Quercus robur were collected from the Yanov district, where the soil contamination by 241 Am and 137 Cs was at the level of 660 and 27 MBq/m 2 , respectively. Gamma spectroscopy and radiochemical methods were used to estimate the activity concentration of 137 Cs, 90 Sr, 238 Pu, 239+240 Pu, 241 Am. The radionuclides were measured in the dry green mass of the plant samples and in the dry soils. The contamination of the Oenothera biennis, Betula pendula and Quercus robur samples by 137 Cs was (5.8±1,5)x10 6 , (7.4±1.1)x10 5 , and (2.6±0.2)x10 6 Bq/kg dry mass, respectively, and contamination by 241 Am was 47±5, 45±3 and 3.2±0.2 Bq/kg, respectively. The soil-to-plant transfer ratio for 137 Cs ranged lay within the interval of 0.2 to 0.03 Bq/kg : Bq/m 2 , the the transfer ratio for 241 Am did not exceed 7x10 -5 Bq/kg : Bq/m 2 . The coefficient of the relative contents of the 241 Am/ 239+240 Pu radionuclides in the various plant samples varied from 3.2 to 8.3, while for soil from

  10. Increased hand washing reduces influenza virus surface contamination in Bangkok households, 2009-2010.

    Science.gov (United States)

    Levy, Jens W; Suntarattiwong, Piyarat; Simmerman, James M; Jarman, Richard G; Johnson, Kara; Olsen, Sonja J; Chotpitayasunondh, Tawee

    2014-01-01

    Within a hand-washing clinical trial, we evaluated factors associated with fomite contamination in households with an influenza-infected child. Influenza virus RNA contamination was higher in households with low absolute humidity and in control households, suggesting that hand washing reduces surface contamination. © 2013 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  11. Increased hand washing reduces influenza virus surface contamination in Bangkok households, 2009–2010

    Science.gov (United States)

    Levy, Jens W; Suntarattiwong, Piyarat; Simmerman, James M; Jarman, Richard G; Johnson, Kara; Olsen, Sonja J; Chotpitayasunondh, Tawee

    2014-01-01

    Within a hand-washing clinical trial, we evaluated factors associated with fomite contamination in households with an influenza-infected child. Influenza virus RNA contamination was higher in households with low absolute humidity and in control households, suggesting that hand washing reduces surface contamination. PMID:24373290

  12. Surface Intermediate Zone of Submerged Turbulent Buoyant Jet in Current

    DEFF Research Database (Denmark)

    Chen, H. B.; Larsen, Torben

    1995-01-01

    This paper deals with the intermediate zone between the jet and plume stages of a submerged buoyant discharge from sea outfall in current. The stability criteria, plume width and height after the intermediate zone and the dilution within the intermediate region have been studied theoretically...

  13. Salinization and arsenic contamination of surface water in southwest Bangladesh.

    Science.gov (United States)

    Ayers, John C; George, Gregory; Fry, David; Benneyworth, Laura; Wilson, Carol; Auerbach, Leslie; Roy, Kushal; Karim, Md Rezaul; Akter, Farjana; Goodbred, Steven

    2017-09-11

    To identify the causes of salinization and arsenic contamination of surface water on an embanked island (i.e., polder) in the tidal delta plain of SW Bangladesh we collected and analyzed water samples in the dry (May) and wet (October) seasons in 2012-2013. Samples were collected from rice paddies (wet season), saltwater ponds used for brine shrimp aquaculture (dry season), freshwater ponds and tidal channels (both wet and dry season), and rainwater collectors. Continuous measurements of salinity from March 2012 to February 2013 show that tidal channel water increases from ~0.15 ppt in the wet season up to ~20 ppt in the dry season. On the polder, surface water exceeds the World Health Organization drinking water guideline of 10 μg As/L in 78% of shrimp ponds and 27% of rice paddies, raising concerns that produced shrimp and rice could have unsafe levels of As. Drinking water sources also often have unsafe As levels, with 83% of tubewell and 43% of freshwater pond samples having >10 μg As/L. Water compositions and field observations are consistent with shrimp pond water being sourced from tidal channels during the dry season, rather than the locally saline groundwater from tubewells. Irrigation water for rice paddies is also obtained from the tidal channels, but during the wet season when surface waters are fresh. Salts become concentrated in irrigation water through evaporation, with average salinity increasing from 0.43 ppt in the tidal channel source to 0.91 ppt in the rice paddies. Our observations suggest that the practice of seasonally alternating rice and shrimp farming in a field has a negligible effect on rice paddy water salinity. Also, shrimp ponds do not significantly affect the salinity of adjacent surface water bodies or subjacent groundwater because impermeable shallow surface deposits of silt and clay mostly isolate surface water bodies from each other and from the shallow groundwater aquifer. Bivariate plots of conservative element

  14. Engineering hyporheic zones for the attenuation of urban pesticides and other stormwater trace organic contaminants

    Science.gov (United States)

    Portmann, A. C.; Halpin, B. N.; Herzog, S.; Higgins, C.; McCray, J. E.

    2017-12-01

    The hyporheic zone (HZ) is a natural bioreactor that can provide in-stream attenuation of various nonpoint source contaminants. Main contributions of nonpoint source pollution are coming from urban stormwater and agricultural runoff, which both adversely impact aquatic life. Stormwater pollutants of concern commonly include nutrients, metals, pathogens, and trace organic contaminants (TOrCs). Despite substantial water quality challenges, current stormwater management typically focuses on water quantity issues rather than pollutant removal. Furthermore, current HZ restoration best management practices do not explicitly control HZ residence times, and generally only induce localized effects. To increase hyporheic exchange and therefore improving water quality, we introduced engineered streambeds featuring modifications to subsurface hydraulic conductivity (K) and reactivity - termed Biohydrochemical Enhancements for Streamwater Treatment (BEST). BEST modifications comprise subsurface modules that employ 1) low-permeability sediments to drive hyporheic exchange and control subsurface residence times, and 2) permeable reactive geomedia to change reaction rates within the HZ. Here we present performance data collected in constructed stream experiments, comparing an all-sand control condition with a stream containing BEST modules and a mixture of 70/30 sand/woodchips (v/v). We evaluated the attenuation of a suite of TOrCs in the BEST versus the control system for two different streambed media: a coarse sand with K = 0.48 cm/s and a fine sand with K = 0.16 cm/s. The range of TOrCs investigated comprises urban pesticides and other stormwater relevant TOrCs. Benefits of applying BEST include increased exchange between streamwater and HZ water, leading to diverse redox conditions that are beneficial for aquatic organisms and will facilitate in-stream pollutant transformation. Future work will focus on tailoring the BEST design for specific pollutants, thereby controlling HZ

  15. Long-term consequences of radioactive surface contamination in agriculture

    International Nuclear Information System (INIS)

    Haak, E.

    1983-01-01

    Based on agricultural statistics of crop and animal produce for 1981, and on transfer coefficients, as obtained from long-term Swedish field experiments and the literature, the transfer of 137-Cs and 90-Sr within the chain: Soil crop - food, and the chain: soil - crop - animal - food was estimated for an average km 2 of farming land in nine different countries, with the assumption that 1 TBq had been deposited at a single event and remained near the surface of grass fields and/or had been incorporated into the plough layer of arable soils prior to reuse after a nuclear accident. Calculations are given in detail, and the results are discussed as regards the situation of unchanged farming and soil management practices. The transfer of the two nuclides from soil to different vectors within the two chains was shown to vary among the countries, due to differences in soil, use of pasture and an arable land, as well as current plant and animal produce. The transfer of nuclides from fodder to food is effectively reduced by the animal link and more so for strontium than for cesium. The contamination recirculates back to the soil. The effect of corrective measures to reduce nuclide transfer from soil to food, by changed fertilizer and soil management practices as well as changes from current farming systems to pig or beef cattle

  16. Literature review of cask exterior surface contamination with application to a nuclear repository

    International Nuclear Information System (INIS)

    Adams, K.G.

    1990-04-01

    The characteristics of transportation cask surface contamination and the ''weeping'' phenomenon are reviewed. In addition, literature that pertains to the possible impact of surface contamination on repository operations is reviewed. This report consists of commentary on and rather extensive excerpts from the published literature on cask surface contamination that may have a bearing on repository risk assessment. In addition, estimates are made of the quantity of contamination that might be present on a cask. These estimates are used to calculate the direct exposure rates to personnel located at several distances from the cask. 15 refs., 15 tabs

  17. Influence of Alkaline Co-Contaminants on Technetium Mobility in Vadose Zone Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Szecsody, James E.; Jansik, Danielle P.; McKinley, James P.; Hess, Nancy J.

    2014-09-01

    Pertechnetate was slowly reduced in a natural, untreated arid sediment under anaerobic conditions (0.02 nmol g-1 h-1), which could occur in low permeability zones in the field, most of which was quickly oxidized. A small portion of the surface Tc may be incorporated into slowly dissolving surface phases, so was not readily oxidized/remobilized into pore water. In contrast, pertechnetate reduction in an anaerobic sediment containing adsorbed ferrous iron as the reductant was rapid (15 to 600 nmol g-1 h-1), and nearly all (96 - 98%) was rapidly oxidized/remobilized (2.6 to 6.8 nmol g-1 h-1) within hours. Tc reduction in an anaerobic sediment containing 0.5 to 10 mM sulfide showed a relatively slow reduction rate (0.01 to 0.03 nmol g-1 h-1) that was similar to observations in the natural sediment. Pertechnetate infiltration into sediment with a highly alkaline water resulted in rapid reduction (0.07 to 0.2 nmol g-1 h-1) from ferrous iron released during biotite or magnetite dissolution. Oxidation of NaOH-treated sediments resulted in slow Tc oxidation (~0.05 nmol g-1 h-1) of a small fraction of the surface Tc (13% to 23%). The Tc remaining on the surface was TcIV (by XANES), and autoradiography and elemental maps of Tc (by electron microprobe) showed Tc was present associated with specific minerals, rather than being evenly distributed on the surface. Dissolution of quartz, montmorillonite, muscovite, and kaolinite also occurred in the alkaline water, resulting in significant aqueous silica and aluminum. Over time, aluminosilicates cancrinite, zeolite and sodalite were precipitating. These precipitates may be coating surface Tc(IV) phases, limiting reoxidation.

  18. Steam stripping of the unsaturated zone of contaminated sub-soils: the effect of diffusion/dispersion in the start-up phase

    NARCIS (Netherlands)

    Brouwers, Jos; Gilding, B.H.

    2006-01-01

    The unsteady process of steam stripping of the unsaturated zone of soils contaminated with volatile organic compounds (VOCs) is addressed. A model is presented. It accounts for the effects of water and contaminants remaining in vapour phase, as well as diffusion and dispersion of contaminants in

  19. Stochastic estimation and simulation of heterogeneities important for transport of contaminants in the unsaturated zone

    Energy Technology Data Exchange (ETDEWEB)

    Kitteroed, Nils-Otto

    1997-12-31

    The background for this thesis was the increasing risk of contamination of water resources and the requirement of groundwater protection. Specifically, the thesis implements procedures to estimate and simulate observed heterogeneities in the unsaturated zone and evaluates what impact the heterogeneities may have on the water flow. The broad goal was to establish a reference model with high spatial resolution within a small area and to condition the model using spatially frequent field observations, and the Moreppen site at Oslo`s new major airport was used for this purpose. An approach is presented for the use of ground penetrating radar in which indicator kriging is used to estimate continuous stratigraphical architecture. Kriging is also used to obtain 3D images of soil moisture. A simulation algorithm based on the Karhunen-Loeve expansion is evaluated and a modification of the Karhunen-Loeve simulation is suggested that makes it possible to increase the size of the simulation lattice. This is obtained by kriging interpolation of the eigenfunctions. 250 refs., 40 figs., 7 tabs.

  20. Assessment of Surface Water Contamination from Coalbed Methane Fracturing-Derived Volatile Contaminants in Sullivan County, Indiana, USA.

    Science.gov (United States)

    Meszaros, Nicholas; Subedi, Bikram; Stamets, Tristan; Shifa, Naima

    2017-09-01

    There is a growing concern over the contamination of surface water and the associated environmental and public health consequences from the recent proliferation of hydraulic fracturing in the USA. Petroleum hydrocarbon-derived contaminants of concern [benzene, toluene, ethylbenzene, and xylenes (BTEX)] and various dissolved cations and anions were spatially determined in surface waters around 15 coalbed methane fracking wells in Sullivan County, IN, USA. At least one BTEX compound was detected in 69% of sampling sites (n = 13) and 23% of sampling sites were found to be contaminated with all of the BTEX compounds. Toluene was the most common BTEX compound detected across all sampling sites, both upstream and downstream from coalbed methane fracking wells. The average concentration of toluene at a reservoir and its outlet nearby the fracking wells was ~2× higher than other downstream sites. However, one of the upstream sites was found to be contaminated with BTEX at similar concentrations as in a reservoir site nearby the fracking well. Calcium (~60 ppm) and sulfates (~175 ppm) were the dominant cations and anions, respectively, in surface water around the fracking sites. This study represents the first report of BTEX contamination in surface water from coalbed methane hydraulic fracturing wells.

  1. Coastal Zone Hazards Related to Groundwater-Surface Water Interactions and Groundwater Flooding

    Science.gov (United States)

    Kontar, Y. A.; Ozorovich, Y. R.; Salokhiddinov, A. T.

    2009-12-01

    as a source of safe and sustainable water supply. In such a situation, a number of scientists consider that the population's water supply must be achieved through a more comprehensive use of fresh and even subsaline groundwater resources from the coastal aquifers. The 2004 tsunami in the Indian Ocean caused a disaster affecting thousands of kilometers of coastal zone in SE Asia. Many coastal wetlands were affected in the short term by the large inflow of salt seawater and littoral sediment deposited during the tsunami, and in the longer-term by changes in their hydrogeology caused by changes to coastlines and damage to sea-defenses. Many water quality and associated problems were generated by the tsunami. The tsunami has created an accelerating process of salt-water intrusion and fresh-water contaminations in affected regions that now require drastic remediation measures. We report here some efforts and results in studying the processes of groundwater-surface water interactions and groundwater flooding creating hazards in the coastal zones.

  2. Materials SIG quantification and characterization of surface contaminants

    Science.gov (United States)

    Crutcher, E. Russ

    1992-01-01

    When LDEF entered orbit its cleanliness was approximately a MIL-STD-1246B Level 2000C. Its burden of contaminants included particles from every part of its history including a relatively small contribution from the shuttle bay itself. Although this satellite was far from what is normally considered clean in the aerospace industry, contaminating events in orbit and from processing after recovery were easily detected. The molecular contaminants carried into orbit were dwarfed by the heavy deposition of UV polymerized films from outgassing urethane paints and silicone based materials. Impacts by relatively small objects in orbit could create particulate contaminants that easily dominated the particle counts within a centimeter of the impact site. During the recovery activities LDEF was 'sprayed' with a liquid high in organics and water soluble salts. With reentry turbulence, vibration, and gravitational loading particulate contaminants were redistributed about LDEF and the shuttle bay.

  3. GWSCREEN: A semi-analytical model for assessment of the groundwater pathway from surface or buried contamination: Version 2.0 theory and user's manual

    International Nuclear Information System (INIS)

    Rood, A.S.

    1993-06-01

    GWSCREEN was developed for assessment of the groundwater pathway from leaching of radioactive and non radioactive substances from surface or buried sources. The code was designed for implementation in the Track I and Track II assessment of CERCLA (Comprehensive Environmental Response, Compensation and Liability Act) sites identified as low probability hazard at the Idaho National Engineering Laboratory (DOE, 1992). The code calculates the limiting soil concentration such that, after leaching and transport to the aquifer, regulatory contaminant levels in groundwater are not exceeded. The code uses a mass conservation approach to model three processes: contaminant release from a source volume, contaminant transport in the unsaturated zone, and contaminant transport in the saturated zone. The source model considers the sorptive properties and solubility of the contaminant. Transport in the unsaturated zone is described by a plug flow model. Transport in the saturated zone is calculated with a semi-analytical solution to the advection dispersion equation in groundwater. In Version 2.0, GWSCREEN has incorporated an additional source model to calculate the impacts to groundwater resulting from the release to percolation ponds. In addition, transport of radioactive progeny has also been incorporated. GWSCREEN has shown comparable results when compared against other codes using similar algorithms and techniques. This code was designed for assessment and screening of the groundwater pathway when field data is limited. It was not intended to be a predictive tool

  4. GWSCREEN: A semi-analytical model for assessment of the groundwater pathway from surface or buried contamination: Version 2.0 theory and user`s manual

    Energy Technology Data Exchange (ETDEWEB)

    Rood, A.S.

    1993-06-01

    GWSCREEN was developed for assessment of the groundwater pathway from leaching of radioactive and non radioactive substances from surface or buried sources. The code was designed for implementation in the Track I and Track II assessment of CERCLA (Comprehensive Environmental Response, Compensation and Liability Act) sites identified as low probability hazard at the Idaho National Engineering Laboratory (DOE, 1992). The code calculates the limiting soil concentration such that, after leaching and transport to the aquifer, regulatory contaminant levels in groundwater are not exceeded. The code uses a mass conservation approach to model three processes: contaminant release from a source volume, contaminant transport in the unsaturated zone, and contaminant transport in the saturated zone. The source model considers the sorptive properties and solubility of the contaminant. Transport in the unsaturated zone is described by a plug flow model. Transport in the saturated zone is calculated with a semi-analytical solution to the advection dispersion equation in groundwater. In Version 2.0, GWSCREEN has incorporated an additional source model to calculate the impacts to groundwater resulting from the release to percolation ponds. In addition, transport of radioactive progeny has also been incorporated. GWSCREEN has shown comparable results when compared against other codes using similar algorithms and techniques. This code was designed for assessment and screening of the groundwater pathway when field data is limited. It was not intended to be a predictive tool.

  5. Radioactive contamination of some rubber or plastic surfaces by fission products. Decontamination tests

    International Nuclear Information System (INIS)

    Mestre, E.; Sautiez, N.

    1957-10-01

    With the objective of notably addressing the contamination and decontamination of gloves and floor covering, this report first presents some characteristics of contaminating radioactive materials (nature, physical and chemical condition), of contaminated surfaces (surface condition, surface nature), and of decontamination processes (physical, chemical or mechanical action). It describes the operational modality implemented to test decontamination processes on various glove or flooring materials: sample preparation, counting, decontamination, reproducibility of decontamination tests, results in terms of activity reduction. It more precisely describes the tested samples: short gloves, gloves from glove boxes, floor and wall coverings. Results are presented and discussed in terms of sample susceptibility to contamination, and of decontamination, but also for re-contamination tests after a Nab-based decontamination (susceptibility to contamination, decontamination gain)

  6. Assessment of surface contamination level in an operating uranium ore processing facility of Jaduguda, India

    International Nuclear Information System (INIS)

    Meena, J.S.; Patnaik, R.L.; Jha, V.N.; Sahoo, S.K.; Ravi, P.M.; Tripathi, R.M.

    2014-01-01

    Radiological concern of the occupational workers and the area is given priority over other safety issue in confirmation with the stipulated guideline of national regulatory agency (AERB/FEFCF/SG-2, 2007). The key concern from the radiological hazard evaluation point of view is air activity, external gamma level and surface contamination. Present investigations was carried out to ascertain the surface contamination level of uranium ore processing facility at Jaduguda, Jharkhand. For a low grade uranium ore processing industry surface contamination is a major concern in product precipitation and recovery section. In view of this, the ore processing plant can broadly be classified into three areas i.e. ion exchange area, precipitation and product recovery section and other areas. The monitoring results incorporate the level of surface contamination of the plant during the last five years. The geometric mean activity of surface contamination level was 31.1, 34.5 and 9.8 Bq dm -2 in ion exchange, product precipitation and recovery and other areas with GSD of 2, 2.5 and 1.9. In most of the cases the surface contamination level was well within the recommended limit of 100 Bq dm -2 for M class uranium compound. Occasional cases of surface contamination levels exceeding the recommended limit were addressed and areas were decontaminated. Based on the study, modification in the design feature of the surface of the finished product section was also suggested so that the decontamination procedure can be more effectively implemented

  7. Mathematical modelling of surface water-groundwater flow and salinity interactions in the coastal zone

    Science.gov (United States)

    Spanoudaki, Katerina; Kampanis, Nikolaos A.

    2014-05-01

    surface water-groundwater model IRENE (Spanoudaki et al., 2009; Spanoudaki, 2010) has been modified in order to simulate surface water-groundwater flow and salinity interactions in the coastal zone. IRENE, in its original form, couples the 3D, non-steady state Navier-Stokes equations, after Reynolds averaging and with the assumption of hydrostatic pressure distribution, to the equations describing 3D saturated groundwater flow of constant density. A semi-implicit finite difference scheme is used to solve the surface water flow equations, while a fully implicit finite difference scheme is used for the groundwater equations. Pollution interactions are simulated by coupling the advection-diffusion equation describing the fate and transport of contaminants introduced in a 3D turbulent flow field to the partial differential equation describing the fate and transport of contaminants in 3D transient groundwater flow systems. The model has been further developed to include the effects of density variations on surface water and groundwater flow, while the already built-in solute transport capabilities are used to simulate salinity interactions. Initial results show that IRENE can accurately predict surface water-groundwater flow and salinity interactions in coastal areas. Important research issues that can be investigated using IRENE include: (a) sea level rise and tidal effects on aquifer salinisation and the configuration of the saltwater wedge, (b) the effects of surface water-groundwater interaction on salinity increase of coastal wetlands and (c) the estimation of the location and magnitude of groundwater discharge to coasts. Acknowledgement The work presented in this paper has been funded by the Greek State Scholarships Foundation (IKY), Fellowships of Excellence for Postdoctoral Studies (Siemens Program), 'A simulation-optimization model for assessing the best practices for the protection of surface water and groundwater in the coastal zone', (2013 - 2015). References

  8. The distance that contaminated aquatic subsidies extend into lake riparian zones

    Science.gov (United States)

    Consumption of emergent aquatic insects by terrestrial invertebrates is a poorly resolved, but potentially important, mechanism of contaminant flux across ecosystem borders leading to contaminant exposure in terrestrial invertevores. We characterized the spatial extent and magnit...

  9. Surface soil contamination standards for Rockwell Hanford Operations

    International Nuclear Information System (INIS)

    Boothe, G.F.

    1981-01-01

    The 200 Areas of the Hanford site contain soils contaminated with levels of radioactivity ranging from fallout concentrations to levels requiring radiological controls. Some contamination is more or less uniformly distributed, and some occurs as discrete specks or spots of activity. Because of the acute need for standards, the Rockwell Environmental Protection (EP) Group proceeded to develop standards; these were approved by Rockwell in October 1979. It must be emphasized that these standards are only applicable to the 200 Areas of the Hanford site or other areas under Rockwell's jurisdiction. It is assumed that access to these areas will always be restricted and that land-use restrictions will be maintained. Contamination limits for areas used by the general public would normally be lower than the limits derived in this case. It appears that the Rockwell standards divided by a factor of 5 to 10 may be reasonable contamination guidelines for the general environment

  10. Stochastic Radiative Transfer Model for Contaminated Rough Surfaces: A Framework for Detection System Design

    Science.gov (United States)

    2013-11-01

    Contaminated surfaces Detection Rough surface BRDF Reflectance Fill factor CFAR Data fusion (Continued on next page.) 16...surfaces, detection, rough surface, BRDF, reflectance, fill factor, distributed binary integration, CFAR , data fusion, distributed sensor system, double...detection, tem)detect(sys)( 1 PP systemmiss  , for a given constraint of constant false alarm ( CFAR ) system-false-alarm probability, )( systemfalseP

  11. Radioecological conditions in the towns, where the status of radioactive contamination zones will change

    International Nuclear Information System (INIS)

    Ageeva, T.N.; Shapsheeva, T.P.; Zajtsev, A.A.; Makarevich, I.A.

    2015-01-01

    The article presents data of changes in the density of soil contamination in settlements where in 2015 change of the status of contaminated areas is possible. Article contains analysis of monitoring of radioactive contamination of food from private farms, the results of radio ecological inspection conducted in 2013-2014. (authors)

  12. Vapor Intrusion Estimation Tool for Unsaturated Zone Contaminant Sources. User’s Guide

    Science.gov (United States)

    2016-08-30

    CONCENTRATIONS Average gravimetric moisture content in vadose zone b (mass of water per mass of dry porous medium) wt% ω 1 – 9 1, 5, 9 Vadose zone...performance relative to the impact of a vadose zone source on groundwater concentrations . The tool described here is focused on vapor-phase...simulations predicting the vapor concentration distribution from a vadose zone source. A large number of simulations were conducted to develop a data set

  13. T Tank Farm Interim Surface Barrier Demonstration -- Vadose Zone Monitoring FY07 Report

    International Nuclear Information System (INIS)

    Zhang, Z. F.; Strickland, Christopher E.; Keller, Jason M.; Wittreich, Curtis D.; Sydnor, Harold A.

    2008-01-01

    CH2M HILL Hanford Group, Inc. is currently in the process of constructing a temporary surface barrier over a portion of the T Tank Farm as part of the T farm Interim Surface Barrier Demonstration Project. The surface barrier is designed to prevent the infiltration of precipitation into the contaminated soil zone created by the Tank T-106 leak and minimize movement of the contamination. As part of the demonstration effort, vadose zone moisture monitoring is being performed to assess the effectiveness of the barrier at reducing soil moisture. A solar-powered and remotely-controlled system was installed to continuously monitor soil water conditions in four instrument nests (i.e., A, B, C, and D) and the site meteorological condition. Each instrument nest was composed of a capacitance probe with multiple sensors, multiple heat-dissipation units, a neutron probe access tube and a datalogger. Nests A and B also contained a drain gauge each. The principle variables monitored for this purpose are soil-water content, soil-water pressure, and soil-water flux. In addition to these, soil temperature, precipitation, and air temperature are measured. Data from each of the dataloggers were transmitted remotely to the receiving computer. The neutron probe access tube was used to perform quarterly manual measurements of soil-water content using a neutron probe. This monitoring system was used to assess the soil water conditions in the soil outside and within the footprint of the surface barrier to be emplaced in the Hanford T Tank Farm. Data to date is baseline under the condition without the interim surface barrier in place. All the instruments except the two drain gauges were functional in FY07. The capacitance-probe measurements showed that the soil-moisture content at relatively shallow depths (e.g., 0.6 and 0.9 m) was increasing since October 2006 and reached the highest in early January 2007 followed by a slight decrease. Soil-moisture contents at the depths of 1.3 m and

  14. Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff.

    Science.gov (United States)

    Anderson, Brian S; Phillips, Bryn M; Voorhees, Jennifer P; Cahn, Michael

    2017-05-15

    Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may be treated with simple systems designed to promote sorption of contaminants to vegetation and soils and promote infiltration. Two example systems are described: a bioswale treatment system for urban stormwater treatment, and a vegetated drainage ditch for treating agriculture irrigation runoff. Both have similar attributes that reduce contaminant loading in runoff: vegetation that results in sorption of the contaminants to the soil and plant surfaces, and water infiltration. These systems may also include the integration of granulated activated carbon as a polishing step to remove residual contaminants. Implementation of these systems in agriculture and urban watersheds requires system monitoring to verify treatment efficacy. This includes chemical monitoring for specific contaminants responsible for toxicity. The current paper emphasizes monitoring of current use pesticides since these are responsible for surface water toxicity to aquatic invertebrates.

  15. 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

  16. Application of the Vapor-phase Multi-stage CMD Test to Characterize Contaminant Mass Discharge Associated with Volatile Organic Contaminant Sources in the Vadose Zone

    Science.gov (United States)

    Brusseau, M. L.; Mainhagu, J.; Morrison, C. N.; Carroll, K. C.

    2014-12-01

    Vapor-phase multi-stage contaminant mass discharge (CMD) tests were conducted at two field sites to measure mass discharge associated with contaminant sources located in the vadose zone. A CMD of 32 g/d was obtained for a site at which soil vapor extraction (SVE) has been in operation for approximately 6 years. The behavior exhibited for the vapor extractions conducted at this site suggests that there is unlikely to be a significant mass of non-vapor-phase contaminant (e.g., DNAPL, sorbed phase) present in the advective domains, and that most remaining mass is likely located in poorly accessible domains. Given the conditions for this site, this remaining mass is hypothesized to be associated with the low-permeability (and higher water saturation) region in the vicinity of the saturated zone and capillary fringe. This is supported by the results of a sediment-coring effort conducted prior to the CMD test. A CMD of 270 g/d was obtained for a site for which there were no prior SVE operations. The behavior exhibited for the vapor extractions conducted at this site suggest that non-vapor-phase contaminant mass (e.g., DNAPL) may be present in the advective domains. This is consistent with the results of prior characterization activities conducted at the site. Hence, the asymptotic conditions observed for this site most likely derive from a combination of rate-limited mass transfer from DNAPL (and sorbed) phases present in the advective domain as well as mass residing in lower-permeability ("non-advective") regions. The CMD values obtained from the tests were used in conjunction with a recently developed vapor-discharge tool to evaluate the impact of the measured CMDs on groundwater quality.

  17. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments.

    Science.gov (United States)

    Furuse, Adilson Yoshio; da Cunha, Leonardo Fernandes; Benetti, Ana Raquel; Mondelli, José

    2007-12-01

    The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1) rinsing with water and drying; (G2) application of an adhesive system; (G3) rinsing and drying, abrasion with finishing disks, etching and application of adhesive system; (G4) rinsing and drying, etching, application of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin-resin interfaces with saliva significantly reduced shear strength, especially after prolonged storage (presin increments.

  18. Bioremediation of hydrocarbon contaminated surface water, groundwater, and soils

    International Nuclear Information System (INIS)

    Piotrowski, M.R.

    1991-01-01

    Bioremediation is currently receiving considerable attention as a remediation option for sites contaminated with hazardous organic compounds. There is an enormous amount of interest in bioremediation, and numerous journals now publish research articles concerning some aspect of the remediation approach. A review of the literature indicates that two basic forms of bioremediation are currently being practiced: the microbiological approach and the microbial ecology approach. Each form has its advocates and detractors, and the microbiological approach is generally advocated by most of the firms that practice bioremediation. In this paper, the merits and disadvantages of these forms are reviewed and a conceptual approach is presented for assessing which form may be most useful for a particular contaminant situation. I conclude that the microbial ecology form of bioremediation may be the most useful for the majority of contaminant situations, and I will present two case histories in support of this hypothesis

  19. Laboratory Studies on Surface Sampling of Bacillus anthracis Contamination: Summary, Gaps, and Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F.; Amidan, Brett G.; Hu, Rebecca

    2011-11-28

    This report summarizes previous laboratory studies to characterize the performance of methods for collecting, storing/transporting, processing, and analyzing samples from surfaces contaminated by Bacillus anthracis or related surrogates. The focus is on plate culture and count estimates of surface contamination for swab, wipe, and vacuum samples of porous and nonporous surfaces. Summaries of the previous studies and their results were assessed to identify gaps in information needed as inputs to calculate key parameters critical to risk management in biothreat incidents. One key parameter is the number of samples needed to make characterization or clearance decisions with specified statistical confidence. Other key parameters include the ability to calculate, following contamination incidents, the (1) estimates of Bacillus anthracis contamination, as well as the bias and uncertainties in the estimates, and (2) confidence in characterization and clearance decisions for contaminated or decontaminated buildings. Gaps in knowledge and understanding identified during the summary of the studies are discussed and recommendations are given for future studies.

  20. Exploring Surface Analysis Techniques for the Detection of Molecular Contaminants on Spacecraft

    Science.gov (United States)

    Rutherford, Gugu N.; Seasly, Elaine; Thornblom, Mark; Baughman, James

    2016-01-01

    Molecular contamination is a known area of concern for spacecraft. To mitigate this risk, projects involving space flight hardware set requirements in a contamination control plan that establishes an allocation budget for the exposure of non-volatile residues (NVR) onto critical surfaces. The purpose of this work will focus on non-contact surface analysis and in situ monitoring to mitigate molecular contamination on space flight hardware. By using Scanning Electron Microscopy and Energy Dispersive Spectroscopy (SEM-EDS) with Raman Spectroscopy, an unlikely contaminant was identified on space flight hardware. Using traditional and surface analysis methods provided the broader view of the contamination sources allowing for best fit solutions to prevent any future exposure.

  1. 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

    The BC Cribs and Trenches, part of the 200 TW 1 OU waste sites, received about 30 Mgal of scavenged tank waste, with possibly the largest inventory of 99Tc ever disposed to the soil at Hanford and site remediation is being accelerated. The purpose of this work was to develop a conceptual model for contaminant fate and transport at the 216-B-26 Trench site to support identification and development and evaluation of remediation alternatives. Large concentrations of 99Tc high above the water table implicated stratigraphy in the control of the downward migration. The current conceptual model accounts for small-scale stratigraphy; site-specific changes soil properties; tilted layers; and lateral spreading. It assumes the layers are spatially continuous causing water and solutes to move laterally across the boundary if conditions permit. Water influx at the surface is assumed to be steady. Model parameters were generated with pedotransfer functions; these were coupled high resolution neutron moisture logs that provided information on the underlying heterogeneity on a scale of 3 inches. Two approaches were used to evaluate the impact of remedial options on transport. In the first, a 1-D convolution solution to the convective-dispersive equation was used, assuming steady flow. This model was used to predict future movement of the existing plume using the mean and depth dependent moisture content. In the second approach, the STOMP model was used to first predict the current plume distribution followed by its future migration. Redistribution of the 99Tc plume was simulated for the no-action alternative and on-site capping. Hypothetical caps limiting recharge to 1.0, 0.5, and 0.1 mm yr-1 were considered and assumed not to degrade in the long term. Results show that arrival time of the MCLs, the peak arrival time, and the arrival time of the center of mass increased with decreasing recharge rate. The 1-D convolution model is easy to apply and can easily accommodate initial

  2. Transformation of primary contaminant in the environment of 30-km planned NPP zone

    International Nuclear Information System (INIS)

    Pavlovich, E.L.; Zhigunova, L.N.; Makovskaya, N.A.

    2011-01-01

    As a result of work fulfillment ambient nitrogen-bearing level of primary contaminant and oncogenic N-nitrosodimethy-lamine as well as human biologic fluid were measured. It was registered, that there are primary contaminants which do not exceed maximum allowable concentration in external entities. However, concentration of secondary contaminant of N-nitrosodimethylamine in atmospheric air exceeds in up to 3 times agreed value of maximum allowable concentration. (authors).

  3. Soil contamination of plant surfaces from grazing and rainfall interactions

    International Nuclear Information System (INIS)

    Hinton, T.G.; Stoll, J.M.; Tobler, L.

    1995-01-01

    Contaminants often attach to soil particles, and their subsequent environmental transport is largely determined by processes that govern soil movement. We examined the influence of grazing intensity on soil contamination of pastures. Four different grazing densities of sheep were tested against an ungrazed control plot. Scandium concentrations were determined by neutron activation analysis and was used as a tracer of soil adhesion on vegetation. Soil loadings ( g soil kg -1 dry plant) increased 60% when grazing intensity was increased by a factor of four (p 0.003). Rain and wind removed soil from vegetation in the ungrazed control plots, but when grazing sheep were present, an increase in rain from 0.3 to 9.7 mm caused a 130% increase in soil contamination. Multiple regression was used to develop an equation that predicts soil loadings as a function of grazing density, rainfall and wind speed (p = 0.0001, r 2 = 0.78). The model predicts that if grazing management were to be used as a tool to reduce contaminant intake from inadvertent consumption of resuspended soil by grazing animals, grazing densities would have to be reduced 2.5 times to reduce soil loadings by 50%. (author)

  4. Metal Hydride assited contamination on Ru/Si surfaces

    NARCIS (Netherlands)

    Pachecka, Malgorzata; Lee, Christopher James; Sturm, Jacobus Marinus; Bijkerk, Frederik

    2013-01-01

    In extreme ultraviolet lithography (EUVL) residual tin, in the form of particles, ions, and atoms, can be deposited on nearby EUV optics. During the EUV pulse, a reactive hydrogen plasma is formed, which may be able to react with metal contaminants, creating volatile and unstable metal hydrides that

  5. Microbial contamination of contact surfaces at eating houses in ...

    African Journals Online (AJOL)

    A study of five highly patronized eating houses in a university community was conducted to assess the microbiological quality of some food contact and ... The predominant bacterial contaminants were isolated, characterized and identified as E. coli, S. aureus, Pseudomonas aeruginosa, Proteus spp., Salmonella spp. and ...

  6. Effects of radionuclide contamination on forest trees in the exclusion zone around the Fukushima Daiichi Nuclear Power Plant

    International Nuclear Information System (INIS)

    Watanabe, Yoshito; Kubota, Yoshihisa; Fuma, Shoichi; Yoshida, Satoshi; Ichikawa, San'ei; Kubota, Masahide; Takano, Toshiyuki; Mizoguchi, Masahiko

    2013-01-01

    A preliminary survey was performed for forest areas within the exclusion zone around the Fukushima Daiichi Nuclear Power Plant, for radionuclide contamination levels and radiation effects on trees during the first year after the March 2011 accident. Even in the most contaminated forest, approximately 3 km west of the power plant, no externally visible symptoms of radiation damage—including yellowing, malformation, and early withering of leaves—were observed in trees, indicating that massive radiation damage did not occur in the surrounding forests after the accident. Radiosensitive coniferous plants were, however, heavily contaminated by the deposition of radionuclides in reproductive organs such as cones, which could cause the exposure of developing seeds. The level of radionuclides in the cones of Japanese cedar trees changed, depending on the contamination level of the forest, which was approximately given by an ambient dose rate. The dose rate of internal exposure in the cones of the most contaminated forest, which was calculated to include exposure from the radionuclides deposited in the organs, was found to be within the criteria dose rate of 4-40 μGy/h selected for pine trees by the ICRP in Publication 108. This raises the necessity of performing more detailed analyses of the cytogenetic and reproductive damage to forest trees in the area. (author)

  7. Unravelling Diurnal Asymmetry of Surface Temperature in Different Climate Zones.

    Science.gov (United States)

    Vinnarasi, R; Dhanya, C T; Chakravorty, Aniket; AghaKouchak, Amir

    2017-08-04

    Understanding the evolution of Diurnal Temperature Range (DTR), which has contradicting global and regional trends, is crucial because it influences environmental and human health. Here, we analyse the regional evolution of DTR trend over different climatic zones in India using a non-stationary approach known as the Multidimensional Ensemble Empirical Mode Decomposition (MEEMD) method, to explore the generalized influence of regional climate on DTR, if any. We report a 0.36 °C increase in overall mean of DTR till 1980, however, the rate has declined since then. Further, arid deserts and warm-temperate grasslands exhibit negative DTR trends, while the west coast and sub-tropical forest in the north-east show positive trends. This transition predominantly begins with a 0.5 °C increase from the west coast and spreads with an increase of 0.25 °C per decade. These changes are more pronounced during winter and post-monsoon, especially in the arid desert and warm-temperate grasslands, the DTR decreased up to 2 °C, where the rate of increase in minimum temperature is higher than the maximum temperature. We conclude that both maximum and minimum temperature increase in response to the global climate change, however, their rates of increase are highly local and depend on the underlying climatic zone.

  8. National Enforcement Initiative: Preventing Animal Waste from Contaminating Surface and Ground Water

    Science.gov (United States)

    This page describes EPA's goal in preventing animal waste from contaminating surface and ground Water. It is an EPA National Enforcement Initiative. Both enforcement cases, and a map of enforcement actions are provided.

  9. Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects.

    LENUS (Irish Health Repository)

    Mohamed, Seif

    2010-05-01

    This study was designed to evaluate the effect of surface contamination on osseointegration of dental implants surrounded by a circumferential bone defect and to compare osseointegration around Osseotite with that around Nanotite implants.

  10. Characterization of silicon surface states at clean and copper contaminated condition via transient capacitance measurement

    Science.gov (United States)

    Song, Lihui; Xie, Meng; Yu, Xuegong; Yang, Deren

    2017-10-01

    Silicon surface is one of the dominant recombination sites for silicon solar cells. Generally, the recombination ability of silicon surface is characterized in terms of surface recombination velocity. However, silicon surface actually contain a series of donor and acceptor levels across the silicon band gap, and therefore the surface recombination velocity is too general to provide detailed information of the silicon surface states. In this paper, we used the measured transient capacitance data to extract the detailed information (like defect energy levels, defect densities, and capture cross sections) of the silicon surface states. Furthermore, the influence of copper contamination on silicon surface states was examined, and it was found that copper contamination can change the localized energy levels of "clean" silicon surface states to the band-like energy levels, meanwhile the defect densities and capture cross sections were both enlarged.

  11. 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

    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...

  12. Chemical analysis of outgassing contaminants on spacecraft surfaces

    Science.gov (United States)

    Mcnutt, R. C.

    1973-01-01

    Methods for analyzing and characterizing outgassing contaminants from such materials as RTV 501 potting compound and S 13 G paint are presented. Fractional distillation of a gross distillate from RTV 501 rubber was carried out and the distilled fractions examined as to their ultraviolet and infrared spectra by gas liquid chromatography. A sensitive technique for structural analysis and molecular identification was found to consist of a gas chromatography-mass spectroscopy system, which was determined to be economically unfeasible at present.

  13. Characteristics of the surface source of radioactive atmospheric aerosols in the 30km Chernobyl zone

    International Nuclear Information System (INIS)

    Garger, E.; Gurgula, B.; Kashpur, V.; Kostezh, A.

    1993-01-01

    Territory contaminated by radionuclides around Chernobyl Nuclear Power Plant is the surface source of radioactive atmospheric aerosols due to the natural wind resuspension and ''technogenic'' activity. The present work is devoted to characterizing this source. Measurements of the spacial distribution of soil contamination, atmospheric dry deposition, volume concentration of radioactive aerosols and their variability in space and time, distribution of the radioactivity according to the size of aerosol particles, and size distribution of ''hot'' particles in the surface layer of the atmosphere were taken and the power of the surface source of the radioactivity aerosol was estimated. (author)

  14. Combined Contamination and Space Environmental Effects on Solar Cells and Thermal Control Surfaces

    Science.gov (United States)

    Dever, Joyce A.; Bruckner, Eric J.; Scheiman, David A.; Stidham, Curtis R.

    1994-01-01

    For spacecraft in low Earth orbit (LEO), contamination can occur from thruster fuel, sputter contamination products and from products of silicone degradation. This paper describes laboratory testing in which solar cell materials and thermal control surfaces were exposed to simulated spacecraft environmental effects including contamination, atomic oxygen, ultraviolet radiation and thermal cycling. The objective of these experiments was to determine how the interaction of the natural LEO environmental effects with contaminated spacecraft surfaces impacts the performance of these materials. Optical properties of samples were measured and solar cell performance data was obtained. In general, exposure to contamination by thruster fuel resulted in degradation of solar absorptance for fused silica and various thermal control surfaces and degradation of solar cell performance. Fused silica samples which were subsequently exposed to an atomic oxygen/vacuum ultraviolet radiation environment showed reversal of this degradation. These results imply that solar cells and thermal control surfaces which are susceptible to thruster fuel contamination and which also receive atomic oxygen exposure may not undergo significant performance degradation. Materials which were exposed to only vacuum ultraviolet radiation subsequent to contamination showed slight additional degradation in solar absorptance.

  15. Methods for the calculation of derived working limits for surface contamination by low-toxicity radionuclides

    International Nuclear Information System (INIS)

    Gibson, J.A.B.; Wrixon, A.D.

    1979-01-01

    Surface contamination is often measured as an indication of the general spread of radioactive contamination in a particular place. Derived working limits, (DWLs) for surface contamination provide figures against which to assess the significance of measurements. Derived working limits for surface contamination were first established for use in the nuclear energy industry. They were designed to cope with a wide range of unspecified radionuclides and were therefore based on the assumption that the contamination was due to the presence of the most hazardous radionuclides, e.g. 90 Sr, 210 Pb, 226 Ra and 239 Pu. While this assumption may still be appropriate when the radionuclide mixture is unknown, there are now many specialized uses of particular low-toxicity radionuclides in universities, hospitals and general industry. If it is known that only a particular radionuclide is present, the general DWL can be replaced by a more specific value. The methods for calculating DWLs for some of the more commonly employed low-toxicity radionuclides are described. The exposure pathways considered are (a) external radiation of the skin and inhalation of airborne material from contaminated surfaces in active areas; (b) external irradiation of the skin and ingestion from contaminated skin. Some consideration is given to the effect of the revised dose equivalent limits in the most recent recommendations of ICRP. (author)

  16. Body Surface Contamination Levels of Residents under Different Evacuation Scenarios after the Fukushima Daiichi Nuclear Power Plant Accident.

    Science.gov (United States)

    Ohba, Takashi; Hasegawa, Arifumi; Kohayagawa, Yoshitaka; Kondo, Hisayoshi; Suzuki, Gen

    2017-09-01

    Body surface contamination levels should be correlated with inhaled actual thyroid doses during evacuation following the Fukushima Daiichi nuclear power plant (FDNPP) accident. Evacuees and residents were screened for body surface contamination using a Geiger-Mueller survey meter. The authors obtained 7,539 individual screening data sheets as well as gamma-spectrometry data from measurements made on clothing of two subjects by using a germanium spectrometer. Body surface contamination levels were analyzed in four residential groups during two different periods: 12-14 and 15-17 March 2011. Contamination levels during 12-14 March in the Tomioka/Okuma/Futaba/Naraha group were very low, indicating that residents evacuated before the radioactive plume reached their towns on 12 March. In contrast, levels in the Namie and Minamisoma groups were higher than those in the other groups in both periods, indicating that these residents were exposed to plumes twice on 12 and 15-16 March. The plume on 12 March was enriched with short-lived radionuclides: averaged proportions of radioactivity (relative to I) from Te, I, and Cs measured in clothing from two subjects were 2.3, 1.1, and 0.1, respectively, after correction for physical decay by 12:00 on 12 March. These proportions are similar to those (relative to I) from Te and Cs in dust sampled by a high-volume air sampler in the zone 20 km from the FDNPP on 12 March: 1.9 and 0.1, respectively. These data indicate that the relative contribution to inhaled thyroid dose of short-lived radionuclides in radioactive plumes released on 12 March could be as much as 37.5% in 1-y-old children.

  17. EM Task 12 - Laser cleaning of Contaminated Painted Surfaces

    International Nuclear Information System (INIS)

    Ames A. Grisanti; Charlene R. Crocker; Robert J. Jensen

    1998-01-01

    Several techniques are available or under development for surface decontamination in nuclear facilities. Each technique has its merits; however, none of them is universally the best choice for all surface decontamination applications. Because of the multitude of factors which influence the environmental and economic aspects of selecting a surface decontamination technique, it is difficult to select the best method in a given situation; an objective basis for comparing techniques is needed. The objective of this project is to develop a software tool for use by personnel selecting a surface decontamination technique. The software will incorporate performance data for available surface decontamination techniques. The beta release of the Surface Decontamination Assistant Software has been completed and has undergone testing at the Energy and Environmental Research Center (EERC). Minor modifications to the software will be completed before the end of November 1998, and a final release of the software will be issued

  18. EM Task 12 - Laser cleaning of contaminated painted surfaces

    International Nuclear Information System (INIS)

    Grisanti, Ames A.; Crocker, Charlene R.; Jensen, Robert R.

    1999-01-01

    Several techniques are available or under development for surface decontamination in nuclear facilities. Each technique has its merits; however, none of them is universally the best choice for all surface decontamination applications. Because of the multitude of factors which influence the environmental and economic aspects of selecting a surface decontamination technique, it is difficult to select the best method in a given situation; an objective basis for comparing techniques is needed. The objective of this project was to develop a software tool for use by personnel selecting a surface decontamination technique. The software incorporates performance data for available surface decontamination techniques. The beta release version of the Surface Decontamination Assistant Software has been completed and has undergone testing at the Energy and Environmental Research Center. Minor modifications to the software were completed, and a final release version of the software is ready to be issued

  19. Pollution from organic contaminants in Greek marine areas, receiving anthropogenic pressures from intense activities in the coastal zone

    Science.gov (United States)

    Hatzianestis, Ioannis

    2014-05-01

    Polycyclic aromatic hydrocarbons (PAHs) are widespread pollutants in marine sediments, receiving the pressures from various anthropogenic activities in the coastal zone. Due to their mutagenic and carcinogenic behaviour, PAHs are classified as priority contaminants to be monitored in environmental quality control schemes. The purpose of this study was to determine the levels of PAHs in coastal areas of Greece directly influenced from the operation of major industrial units in the coastal zone, investigate their sources and evaluate their potential toxicity by comparison against effect - based sediment quality guidelines. Thirty two surface sediment samples were collected from three areas of the Hellenic coastline: a) Antikyra bay in Korinthiakos gulf, influenced from the operation of an alumina and aluminium production plant b) Larymna bay in Noth Evoikos gulf, influenced from the operation of a nickel production plant and c) Aliveri bay in South Evoikos Gulf, influenced from a cement production plant. In all the areas studied, aquaculture and fishing activities have been also developed in the coastal zone. PAH concentrations were determined by GC-MS, after soxhlet extraction and fractionation by silica column chromatography. PAH sources and origin were investigated by applying several isomeric ratio diagnostic criteria. The mean quotient Effect- Range Median (m-ERM) was used to evaluate the potential of adverse effects posed to benthic organisms. Three m-ERM-q values were used to differentiate the probability of observing toxicity and classify sites into four categories: sediments with m-ERM1.5 have the highest probability (76%) of toxicity. Extremely high PAH concentrations more than 100,000 ng/g were found in the close vicinity of the alumina production plant in Antikyra bay. High levels of PAHs up to 22,000 ng/g were also found in Aliveri bay, whereas lowest values, but still indicating significant pollution, were measured close to the nickel production plant

  20. Study of surface potential contamination in radioisotope and radiopharmaceutical production facilities and alternative solutions

    International Nuclear Information System (INIS)

    Suhaedi Muhammad; Rimin Sumantri; Farida Tusafariah; Djarwanti Rahayu Pipin Soedjarwo

    2013-01-01

    Radioisotope and radiopharmaceutical production facilities that exist in their operations around the world in the form of radiological impacts of radiation exposure, contamination of surface and air contamination. Given the number of existing open source in radioisotope and radiopharmaceutical production facility, then the possibility of surface contamination in the work area is quite high. For that to protect the safety and health of both workers, the public and the environment, then the licensee must conduct an inventory of some of the potential that could result in contamination of surfaces in radioisotope and radiopharmaceutical production facilities. Several potential to cause surface contamination in radioisotope and radiopharmaceutical production facilities consist of loss of resources, the VAC system disorders, impaired production facilities, limited resources and lack of work discipline and radioactive waste handling activities. From the study of some potential, there are several alternative solutions that can be implemented by the licensee to address the contamination of the surface so as not to cause adverse radiological impacts for both radiation workers, the public or the environment. (author)

  1. Study on Microbial Deposition and Contamination onto Six Surfaces Commonly Used in Chemical and Microbiological Laboratories

    Directory of Open Access Journals (Sweden)

    Elena Tamburini

    2015-07-01

    Full Text Available The worktops in both chemical and microbiological laboratories are the surfaces most vulnerable to damage and exposure to contamination by indoor pollutants. The rate at which particles are deposited on indoor surfaces is an important parameter to determine human exposure to airborne biological particles. In contrast to what has been established for inorganic pollutants, no limit has been set by law for microbial contamination in indoor air. To our knowledge, a comparative study on the effect of surfaces on the deposition of microbes has not been carried out. An evaluation of the microbial contamination of worktop materials could be of crucial importance, both for safety reasons and for the reliability of tests and experiments that need to be carried out in non-contaminated environments. The aim of this study was to evaluate the overall microbial contamination (fungi, mesophilic and psychrophilic bacteria, staphylococci on six widely used worktop materials in laboratories (glass, stainless steel, fine porcelain stoneware, post-forming laminate, high-performing laminate and enamel steel and to correlate it with the characteristics of the surfaces. After cleaning, the kinetics of microbial re-contamination were also evaluated for all surfaces.

  2. Laser surface pretreatment of 100Cr6 bearing steel – Hardening effects and white etching zones

    Energy Technology Data Exchange (ETDEWEB)

    Buling, Anna, E-mail: a.buling@hs-osnabrueck.de [Faculty of Engineering and Computer Science, University of Applied Sciences, 49009 Osnabrück (Germany); Sändker, Hendrik; Stollenwerk, Jochen [Fraunhofer Institute for Laser Technology ILT, Steinbachstrasse 15, 52074 Aachen (Germany); Krupp, Ulrich; Hamann-Steinmeier, Angela [Faculty of Engineering and Computer Science, University of Applied Sciences, 49009 Osnabrück (Germany)

    2016-08-15

    Highlights: • Laser surface pretreatment of the bearing steel 100Cr6 is performed. • Microstructural changes of the surface are examined by light microscopy and SEM. • Topographical changes are observed using white light interferometry. • Micro-hardness testing show the existence of very hard white etching zones (WEZ). • WEZ are attributed to near-surface reaustenitization and rapid quenching. • Dark etching zones (DEZ) are found at the laser path edges after laser pretreatment. - Abstract: In order to achieve a surface pretreatment of the bearing steel 100Cr6 (1–1.5 wt.% Cr) a laser-based process was used. The obtained modification may result in an optimization of the adhesive properties of the surface with respect to an anticorrosion polymer coating on the basis of PEEK (poly-ether-ether-ketone), which is applied on the steel surface by a laser melting technique. This work deals with the influence of the laser-based pretreatment regarding the surface microstructure and the micro-hardness of the steel, which has been examined by scanning electron microscopy (SEM), light microscopy and automated micro-hardness testing. The most suitable parameter set for the laser-based pretreatment leads to the formation of very hard white etching zones (WEZ) with a thickness of 23 μm, whereas this pretreatment also induces topographical changes. The occurrence of the white etching zones is attributed to near-surface re-austenitization and rapid quenching. Moreover, dark etching zones (DEZ) with a thickness of 32 μm are found at the laser path edges as well as underneath the white etching zones (WEZ). In these areas, the hardness is decreased due to the formation of oxides as a consequence of re-tempering.

  3. Biogeochemical Factors Influencing the Transport and Fate of Colloids and Colloid-Associated Contaminants in the Vadose Zone

    Science.gov (United States)

    Bradford, S. A.

    2016-12-01

    The vadose zone exhibits large spatial and temporal variability in many physical, chemical, and biological factors that strongly influence the transport and fate of colloids (e.g., microbes, nanoparticles, clays, and dissolved organic matter) and colloid-associated contaminants (e.g., heavy metals, radionuclides, pesticides, and antibiotics). This presentation highlights our research activities to better understand and predict the influence of specific biogeochemical processes on colloid and colloid-facilitated transport. Results demonstrate the sensitivity of colloid transport, retention, release, and clogging to transients in solution chemistry (e.g., ionic strength, pH, cation and anion type, and surfactants), water velocity and saturation, and preferential flow. Mathematical modeling at interface-, pore-, and continuum-scales is shown to be a critical tool to quantify the relative importance and coupling of these biogeochemical factors on colloid and contaminant transport and fate, which otherwise might be experimentally intractable. Existing gaps in knowledge and model limitations are identified.

  4. Nitrogen cycling across the Peruvian oxygen minimum zone surface sediments

    Science.gov (United States)

    Sommer, S.; Bohlen, L.; Dale, A. W.; Wallmann, K.; Noffke, A.; Hensen, C.; Mosch, T.; Pfannkuche, O.

    2012-04-01

    Oxygen minimum zones (OMZ) are key regions for pelagic and benthic nitrogen turnover. During Meteor cruise M77 (Oct. - Dec. 2008) benthic nitrogen cycling along a latitudinal depth transect (85 to 1000 m) across the Peruvian OMZ at 11°S was studied involving in situ flux measurements, pore water geochemistry as well as diagenetic modeling. Along this transect bottom water oxygen levels were minor importance on the shelf and upper slope but was the dominant N sink at 1000 m. Mass balance calculations as well as modeling indicate that dissimilatory nitrate reduction to ammonium (DNRA) by sulfur bacteria and ammmonification were the main source pathways for ammonium to the bottom water, yielding release rates of up to 4.6 mmol m-2 d-1. DNRA retains DIN within the ecosystem and counteracts the removal of DIN via denitrification and/or anammox. This finding is in contrast to the current opinion that slope sediments in general represent major sinks for DIN.

  5. Microbial contaminants on some fish contact surfaces in Sokoto ...

    African Journals Online (AJOL)

    Sokoto central market and two privately owned fish cold room and distribution outlets were visited between August and September, 2005 to collect surface swabs. The sampled surfaces included a concrete table and two basins from the market, weighing pans, floor and walls of cold rooms from the two distribution outlets.

  6. Mapping the environmental risk potential on surface water of pesticide contamination in the Prosecco's vineyard terraced landscape

    Science.gov (United States)

    Pizarro, Patricia; Ferrarese, Francesco; Loddo, Donato; Eugenio Pappalardo, Salvatore; Varotto, Mauro

    2016-04-01

    Detection and Ranging (LiDAR) have been used to map vineyards and to evaluate slope and drainage systems. All the data and statistics analyses have been performed in GIS environment. The areas of surface water located within a buffer zone of 20 linear meters from vineyard perimeter were considered at risk of pesticide contamination, according to European guidelines and on-site experimental results about the pesticide drift effect. Preliminary results show that 26 ha of the total vineyards within the river basin can potentially affect surface water bodies, highlighting that 19,410 m of perimeter is within 20 m from water courses. Moreover, vineyard classification based on proximity analysis indicates that 6.8 ha are at very high potential risk (10 m).

  7. Contamination of Teflon surfaces by PCBs in the atmosphere

    Science.gov (United States)

    Murphy, Thomas J.; Sweet, Clyde W.

    Collection of a valid precipitation sample involves careful attention to all aspects of the sampling and analysis process. Difficulties in obtaining low field blanks were experienced for a collector used in a project to determine precipitation inputs to Green Bay of Lake Michigan. The cause of high field blanks was found to be PCBs scavenged from the atmosphere and adsorbed on the Teflon™ surface of the sampler. These PCBs were extracted from the collector surface by the methanol used as a rinse solvent. The amounts of PCBs on the surface were found to be a factor of 20-50 higher than the amounts in a typical precipitation sample. After rinsing the Teflon surface several times with methanol, additional PCBs could be obtained by rinsing the surface with hexane or dichloromethane.

  8. Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone

    OpenAIRE

    Bonzom , Jean-Marc; Hättenschwiler , Stephan; Lecomte-Pradines , Catherine; Chauvet , Eric; Gaschak , Sergey; Beaugelin-Seiller , Karine; Della-Vedova , Claire; Dubourg , Nicolas; Maksimenko , Andrey; Garnier-Laplace , Jacqueline; Adam-Guillermin , Christelle

    2016-01-01

    International audience; The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely un- known. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the function- ing of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black a...

  9. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    Directory of Open Access Journals (Sweden)

    Adilson Yoshio Furuse

    2007-12-01

    Full Text Available The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1 rinsing with water and drying; (G2 application of an adhesive system; (G3 rinsing and drying, abrasion with finishing disks, etching and application of adhesive system; (G4 rinsing and drying, etching, application of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin-resin interfaces with saliva significantly reduced shear strength, especially after prolonged storage (p<0.05. Similar values to the original bond strength were obtained after abrasion and application of adhesive (G3 or etching and application of silane and adhesive (G4. If contamination occurs, a surface treatment is required to guarantee an adequate interaction between the resin increments.

  10. Development of an automatic smear sampler and a polymer film for surface radioactive contamination assay

    International Nuclear Information System (INIS)

    Seo, B.-K.; Lee, K.-W.; Woo, Z.-H.; Jeong, K.-S.; Oh, W.-Z.; Han, M.-J.

    2004-01-01

    Measurement of the surface contamination by an indirect method is subject to the various kinds of error according to the sampling person and needs much time and effort in the sampling and assay. In this research, an automatic smear sampler is developed. It improved efficiency for assay work of surface contamination level achieved periodically in a radiation controlled area. Using an automatic smear sampler developed, it is confirmed that radioactive contaminated materials are uniformly transferred to smear paper more than any sampling method by an operator. Also, Solid scintillation proximity membranes were prepared for measuring the amount of radioactive contamination in laboratories contaminated by the low energy beta-ray emitter, such as 3 H and 14 C. Polysulfone scintillation proximity membranes were prepared by impregnating Cerium Activated Yttrium Silicate (CAYS), an inorganic fluor, in a membrane structure. The inorganic fluor-impregnated membranes were applied to detect the radioactive surface contamination. The preparation of membranes was divided into two processes. A supporting polymer film was made of casting solutions consisting of polysulfone and solvent, their cast film being solidified by vacuum evaporation. CAYS-dispersed polymer solutions were cast over the first, solidified polymer films and coagulated either by evaporating solvent in the solution with non-solvent in a coagulation bath. The prepared membranes had two distinguished, but tightly attached, double layers : one is the supporting layer of dense polymer film and the other results revealed that the prepared membranes were efficient to monitor radioactive contamination with reliable counting ability. For enhancement of pick-up and measurement efficiency, the membrane was prepared with the condition of different membrane solidification. The scintillation produced by interaction with radiation and CAYS was measured with photomultiplier tube. The test results showed that the prepared

  11. Geohydrology and susceptibility of major aquifers to surface contamination in Alabama, area 7

    Science.gov (United States)

    Mooty, W.S.

    1987-01-01

    The geohydrology and susceptibility of the seven major aquifers to surface contamination in Area 7 - Bibb, Dallas, Hale, Perry, and Wilcox Counties, are described. Aquifers in the northern part of the study area are in Paleozoic limestones and dolomite formations. Deposits in the central part of the study area are predominately of Cretaceous age and contain the Coker, Gordo, and Eutaw aquifers. Although the southern part of the study area has many deposits of Tertiary age, the Ripley Formation of Cretaceous age is the major aquifer. Contamination of any of the major aquifers is improbable because the majority of the recharge area for the primary aquifers is woodland, pasture, or farmland. Downdip from their outcrops, the major aquifers in the study area are protected from land surface contamination by relatively impermeable layers of clay and chalk. The aquifers that are highly susceptible to contamination are the ones in the limestone and dolomite formations in northern Bibb County. Sinkholes exist in the recharge area of these formations and could provide a direct link for contaminates from the land surface to the water table. An area northeast of the Selma well field is also highly susceptible to contamination. The Eutaw Formation in this area is overlain by alluvial deposits that could increase recharge to the aquifer by slowing the runoff rate of surface water. (USGS)

  12. Survival of foodborne pathogens on stainless steel surfaces and cross-contamination to foods

    NARCIS (Netherlands)

    Kusumaningrum, H.D.; Riboldi, G.; Hazeleger, W.C.; Beumer, R.R.

    2003-01-01

    The retention of bacteria on food contact surfaces increases the risk of cross-contamination of these microorganisms to food. The risk has been considered to be lowered when the surfaces are dry, partly because bacterial growth and survival would be reduced. However, some non-spore-forming bacteria

  13. Quantifying potential sources of surface water contamination with Campylobacter jejuni and Campylobacter coli

    NARCIS (Netherlands)

    Mughini-Gras, Lapo; Penny, Christian; Ragimbeau, Catherine; Schets, Franciska M.; Blaak, Hetty; Duim, Birgitta; Wagenaar, Jaap A.; Boer, de Albert; Cauchie, Henry-Michel; Mossong, Joel; Pelt, Van Wilfrid

    2016-01-01

    Campylobacter is the most common causative agent of human bacterial gastroenteritis and is frequently found in surface water, where it indicates recent contamination with animal faeces, sewage effluent, and agricultural run-off. The contribution of different animal reservoirs to surface water

  14. Fixation of soil surface contamination using natural polysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Sackschewsky, M.R.

    1993-09-01

    Natural polysaccharides were evaluated as alternatives to commercially available dust-control agents for application in buried-waste and contaminated-soil remediation situations. Materials were identified and evaluated with specific criteria in mind: the materials must be environmentally benign and must not introduce any additional hazardous materials; they must be effective for at least 2 or 3 days, but they do not necessarily have to be effective for more than 2 to 3 weeks; they should be relatively resistant to light traffic; they must not interfere with subsequent soil treatment techniques, especially soil washing; and they must be relatively inexpensive. Two products, a pregelled potato starch and a mixture of carbohydrates derived from sugar beets, were selected for evaluation. Testing included small- and large-scale field demonstrations, laboratory physical property analyses, and wind-tunnel evaluations.

  15. Fixation of soil surface contamination using natural polysaccharides

    International Nuclear Information System (INIS)

    Sackschewsky, M.R.

    1993-09-01

    Natural polysaccharides were evaluated as alternatives to commercially available dust-control agents for application in buried-waste and contaminated-soil remediation situations. Materials were identified and evaluated with specific criteria in mind: the materials must be environmentally benign and must not introduce any additional hazardous materials; they must be effective for at least 2 or 3 days, but they do not necessarily have to be effective for more than 2 to 3 weeks; they should be relatively resistant to light traffic; they must not interfere with subsequent soil treatment techniques, especially soil washing; and they must be relatively inexpensive. Two products, a pregelled potato starch and a mixture of carbohydrates derived from sugar beets, were selected for evaluation. Testing included small- and large-scale field demonstrations, laboratory physical property analyses, and wind-tunnel evaluations

  16. Surface hydrophobicity of slippery zones in the pitchers of two Nepenthes species and a hybrid

    Science.gov (United States)

    Wang, Lixin; Zhou, Qiang

    2016-01-01

    To investigate the hydrophobicity of slippery zones, static contact angle measurement and microstructure observation of slippery surfaces from two Nepenthes species and a hybrid were conducted. Marginally different static contact angles were observed, as the smallest (133.83°) and greatest (143.63°) values were recorded for the N. alata and N. miranda respectively, and the median value (140.40°) was presented for the N. khasiana. The slippery zones under investigation exhibited rather similar surface morphologies, but different structural dimensions. These findings probably suggest that the geometrical dimensions of surface architecture exert primary effects on differences in the hydrophobicity of the slippery zone. Based on the Wenzel and Cassie-Baxter equations, models were proposed to analyze the manner in which geometrical dimensions affect the hydrophobicity of the slippery surfaces. The results of our analysis demonstrated that the different structural dimensions of lunate cells and wax platelets make the slippery zones present different real area of the rough surface and thereby generate somewhat distinguishable hydrophobicity. The results support a supplementary interpretation of surface hydrophobicity in plant leaves, and provide a theoretical foundation for developing bioinspired materials with hydrophobic properties and self-cleaning abilities.

  17. Étude de la contamination de surface des carcasses de bovins dans ...

    African Journals Online (AJOL)

    SARAH

    30 juin 2017 ... la flore bactérienne pendant le refroidissement, le stockage et la distribution. Les zones d'abattage sont l'un des principaux points critiques dans l'hygiène de la viande. L'abattage est la principale phase de contamination. Ainsi, 80 à 90 % de la microflore trouvés dans la viande provenant d'abattoirs (Jouve ...

  18. Influence the technogenic disaster at radionuclide contaminated Chernobyl zone on transgeneration changes of plants

    International Nuclear Information System (INIS)

    Rashydov, N.

    2017-01-01

    Some of the territories have naturally increased level of radiation as areas of native radioecological anomalies, but others were polluted as a result of nuclear weapon testing, nuclear waste leakage, and nuclear power plants disasters, such as Chernobyl nuclear power plant (CNPP) and Fukushima. Eventually, the large areas have been strong contaminated with radioactivity isotopes for long term. Despite more than thirty years aftermath the explosion of the CNPP accident, the problems coming from the high radionuclide contamination of the environment and the effects of chronic radiation on living organisms still remain relevant. Because the recent tragedy at the Fukushima Nuclear Power Plant in Japan is chillingly reminiscent of the world's worst nuclear disaster at Chernobyl, Ukraine in 1986. Our research addressing the effects of chronic ionizing radiation on plants, the ongoing success of plants adaptation and transgeneration changes in radio-contaminated Chernobyl area was revealed. The focus our investigation is on a role of the small dose chronic radiation due to plant biodiversity processes because it is a common adverse environmental toxicology factor. In order to characterize proteomes of plants adapting to biodiversity at radio-contaminated Chernobyl area we established non-radioactive and radio-contaminated experimental fields.

  19. The Development of a Sub-Surface Monitoring System for Organic Contamination in Soils and Groundwater

    Directory of Open Access Journals (Sweden)

    Sharon L. Huntley

    2002-01-01

    Full Text Available A major problem when dealing with environmental contamination is the early detection and subsequent surveillance of the contamination. This paper describes the potential of sub-surface sensor technology for the early detection of organic contaminants in contaminated soils, sediments, and landfill sites. Rugged, low-power hydrocarbon sensors have been developed, along with a data-logging system, for the early detection of phase hydrocarbons in soil. Through laboratory-based evaluation, the ability of this system to monitor organic contamination in water-based systems is being evaluated. When used in conjunction with specific immunoassays, this can provide a sensitive and low-cost solution for long-term monitoring and analysis, applicable to a wide range of field applications.

  20. Two-pulse rapid remote surface contamination measurement.

    Energy Technology Data Exchange (ETDEWEB)

    Headrick, Jeffrey M.; Kulp, Thomas J.; Bisson, Scott E.; Reichardt, Thomas A.; Farrow, Roger L.

    2010-11-01

    This project demonstrated the feasibility of a 'pump-probe' optical detection method for standoff sensing of chemicals on surfaces. Such a measurement uses two optical pulses - one to remove the analyte (or a fragment of it) from the surface and the second to sense the removed material. As a particular example, this project targeted photofragmentation laser-induced fluorescence (PF-LIF) to detect of surface deposits of low-volatility chemical warfare agents (LVAs). Feasibility was demonstrated for four agent surrogates on eight realistic surfaces. Its sensitivity was established for measurements on concrete and aluminum. Extrapolations were made to demonstrate relevance to the needs of outside users. Several aspects of the surface PF-LIF physical mechanism were investigated and compared to that of vapor-phase measurements. The use of PF-LIF as a rapid screening tool to 'cue' more specific sensors was recommended. Its sensitivity was compared to that of Raman spectroscopy, which is both a potential 'confirmer' of PF-LIF 'hits' and is also a competing screening technology.

  1. Modeling of Transmittance Degradation Caused by Optical Surface Contamination by Atomic Oxygen Reaction with Adsorbed Silicones

    Science.gov (United States)

    Snyder, Aaron; Banks, Bruce; Miller, Sharon; Stueber, Thomas; Sechkar, Edward

    2001-01-01

    A numerical procedure is presented to calculate transmittance degradation caused by contaminant films on spacecraft surfaces produced through the interaction of orbital atomic oxygen (AO) with volatile silicones and hydrocarbons from spacecraft components. In the model, contaminant accretion is dependent on the adsorption of species, depletion reactions due to gas-surface collisions, desorption, and surface reactions between AO and silicone producing SiO(x), (where x is near 2). A detailed description of the procedure used to calculate the constituents of the contaminant layer is presented, including the equations that govern the evolution of fractional coverage by specie type. As an illustrative example of film growth, calculation results using a prototype code that calculates the evolution of surface coverage by specie type is presented and discussed. An example of the transmittance degradation caused by surface interaction of AO with deposited contaminant is presented for the case of exponentially decaying contaminant flux. These examples are performed using hypothetical values for the process parameters.

  2. Temporal–spatial variation and partitioning prediction of antibiotics in surface water and sediments from the intertidal zones of the Yellow River Delta, China

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Shengnan [State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875 (China); Liu, Xinhui, E-mail: xhliu@bnu.edu.cn [State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875 (China); Cheng, Dengmiao [Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture, Beijing 100081 (China); Liu, Guannan [MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, CAGS, Beijing 100037 (China); Liang, Baocui; Cui, Baoshan; Bai, Junhong [State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875 (China)

    2016-11-01

    As special zones, the intertidal zones of the Yellow River Delta (YRD) are highly variable along with time and space. Fluvial–marine and land–ocean interactions which frequently occur in these areas have a great impact on the fate of pollutants. Antibiotics, which contribute to antibiotic-resistant genes (ARGs), are widely detected in wastewater, natural water, soil, sediments, and even drinking water. Therefore, it is meaningful to investigate the occurrence and fate of antibiotics in these special zones. In this study, eight antibiotics belonging to tetracyclines (TCs), fluoroquinolones (FQs), and macrolides (MLs) were detected in the surface water and sediments from the intertidal zones of YRD during two seasons. Two models were established to predict the partitioning coefficients of norfloxacin (NOR) and erythromycin (ETM) using physicochemical properties of sediments, respectively. The total concentrations of these antibiotics were 82.94–230.96 ng·L{sup −} {sup 1} and 40.97–207.44 ng·g{sup −} {sup 1}, respectively, in the surface water and sediments. Seasonal variation was mainly influenced by the frequency of antibiotics use and environment factors. The regions with river supply exhibited the highest concentrations of antibiotics in surface water and sediments. Meanwhile, particle-size fractions, cation exchange capability (CEC), and metal ions content played dominant roles in the partitioning behaviors of NOR and ETM between the surface water and sediments. Both models established in this study featured accuracy and feasibility, which provided the methods for predicting the partitioning coefficients of emerging contaminants similar in structures to NOR and ETM in the intertidal zones. - Highlights: • The intertidal zones of YRD were polluted by antibiotics to some extent. • The river supply was a major pathway for the antibiotic pollution of the intertidal zones of YRD. • The partitioning coefficients of NOR and ETM can be predicted using

  3. Temporal–spatial variation and partitioning prediction of antibiotics in surface water and sediments from the intertidal zones of the Yellow River Delta, China

    International Nuclear Information System (INIS)

    Zhao, Shengnan; Liu, Xinhui; Cheng, Dengmiao; Liu, Guannan; Liang, Baocui; Cui, Baoshan; Bai, Junhong

    2016-01-01

    As special zones, the intertidal zones of the Yellow River Delta (YRD) are highly variable along with time and space. Fluvial–marine and land–ocean interactions which frequently occur in these areas have a great impact on the fate of pollutants. Antibiotics, which contribute to antibiotic-resistant genes (ARGs), are widely detected in wastewater, natural water, soil, sediments, and even drinking water. Therefore, it is meaningful to investigate the occurrence and fate of antibiotics in these special zones. In this study, eight antibiotics belonging to tetracyclines (TCs), fluoroquinolones (FQs), and macrolides (MLs) were detected in the surface water and sediments from the intertidal zones of YRD during two seasons. Two models were established to predict the partitioning coefficients of norfloxacin (NOR) and erythromycin (ETM) using physicochemical properties of sediments, respectively. The total concentrations of these antibiotics were 82.94–230.96 ng·L − 1 and 40.97–207.44 ng·g − 1 , respectively, in the surface water and sediments. Seasonal variation was mainly influenced by the frequency of antibiotics use and environment factors. The regions with river supply exhibited the highest concentrations of antibiotics in surface water and sediments. Meanwhile, particle-size fractions, cation exchange capability (CEC), and metal ions content played dominant roles in the partitioning behaviors of NOR and ETM between the surface water and sediments. Both models established in this study featured accuracy and feasibility, which provided the methods for predicting the partitioning coefficients of emerging contaminants similar in structures to NOR and ETM in the intertidal zones. - Highlights: • The intertidal zones of YRD were polluted by antibiotics to some extent. • The river supply was a major pathway for the antibiotic pollution of the intertidal zones of YRD. • The partitioning coefficients of NOR and ETM can be predicted using the physicochemical

  4. Application Of The SPV-based Surface Lifetime Technique To In-Line Monitoring Of Surface Cu Contamination

    Science.gov (United States)

    D'Amico, John; Savtchouk, Alexandre; Wilson, Matthew; Kim, Chul Hong; Yoo, Hyung Won; Lee, Chang Hwan; Kim, Tae Kyoung; Son, Sang Hoon

    2009-09-01

    Implementation of Cu interconnects into Silicon Integrated Circuits (IC's) has been instrumental in the continuing improvement of IC device performance. Copper as a well known Gate Oxide Integrity (GOI) killer [1, 2] requires extensive protocols to minimize the possibility of cross contamination. Despite such protocols the risk for cross contamination exists, and consequently there is the need for in-line Cu cross-contamination detection metrology. Preferably the metrology will be non-destructive, fast, and capable of mapping on product wafers. Up to now the most common approaches for monitoring Cu contamination in IC fabrication lines either measure Cu in the bulk Si, which is not applicable to Cu cross-contamination monitoring because Back-End-of-the-Line thermal budgets restrict the ability to diffuse the surface Cu into the bulk Si; or the techniques are not optimal for in-line monitoring due to their destructive, time-consuming, or costly nature. In this work we demonstrate for the first time the application of the ac-Surface Photo Voltage (ac-SPV) surface lifetime approach [3] to in-line, full wafer coverage mapping of low level (metrology system. Furthermore, because the metrology is non-contact (utilizing edge-grip handling) and non-destructive, it is directly applicable to measurement of production wafers. In-line fab data acquired using this metrology is presented and compared to data from Inductively Coupled Plasma Mass Spectroscopy (ICP-MS).

  5. 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

    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...

  6. evaluation of metal contaminants of surface water sources in an ...

    African Journals Online (AJOL)

    SAMSUNG

    This study evaluated the potential health risks associated with domestic use of surface water from an active Pb-Zn mine pit, compared to a ... about the health and environmental risks associated with high levels of metal ... S. O. Ngele, Department of Industrial Chemistry, Ebonyi State University Abakaliki, Nigeria. E. J. Itumoh ...

  7. Surface sterilization method for reducing microbial contamination of ...

    African Journals Online (AJOL)

    An effective disinfection method for strawberry (Fragaria x ananassa Duch.) cv. Senga Sengana micropropagation using runner tips and nodal segments as explants was developed. The explants were surface sterilized with different sterilants for different durations. The present studies on the effect of different regimes of ...

  8. Investigation of Polyaniline and a Functionalised Derivative as Antimicrobial Additives to Create Contamination Resistant Surfaces

    Directory of Open Access Journals (Sweden)

    Julia Robertson

    2018-03-01

    Full Text Available Antimicrobial surfaces can be applied to break transmission pathways in hospitals. Polyaniline (PANI and poly(3-aminobenzoic acid (P3ABA are novel antimicrobial agents with potential as non-leaching additives to provide contamination resistant surfaces. The activity of PANI and P3ABA were investigated in suspension and as part of absorbent and non-absorbent surfaces. The effect of inoculum size and the presence of organic matter on surface activity was determined. PANI and P3ABA both demonstrated bactericidal activity against Escherichia coli and Staphylococcus aureus in suspension and as part of an absorbent surface. Only P3ABA showed antimicrobial activity in non-absorbent films. The results that are presented in this work support the use of P3ABA to create contamination resistant surfaces.

  9. Surface contamination of hazardous drug pharmacy storage bins and pharmacy distributor shipping containers.

    Science.gov (United States)

    Redic, Kimberly A; Fang, Kayleen; Christen, Catherine; Chaffee, Bruce W

    2018-03-01

    Purpose This study was conducted to determine whether there is contamination on exterior drug packaging using shipping totes from the distributor and carousel storage bins as surrogate markers of external packaging contamination. Methods A two-part study was conducted to measure the presence of 5-fluorouracil, ifosfamide, cyclophosphamide, docetaxel and paclitaxel using surrogate markers for external drug packaging. In Part I, 10 drug distributor shipping totes designated for transport of hazardous drugs provided a snapshot view of contamination from regular use and transit in and out of the pharmacy. An additional two totes designated for transport of non-hazardous drugs served as controls. In Part II, old carousel storage bins (i.e. those in use pre-study) were wiped for snapshot view of hazardous drug contamination on storage bins. New carousel storage bins were then put into use for storage of the five tested drugs and used for routine storage and inventory maintenance activities. Carousel bins were wiped at time intervals 0, 8, 16 and 52 weeks to measure surface contamination. Results Two of the 10 hazardous shipping totes were contaminated. Three of the five-old carousel bins were contaminated with cyclophosphamide. One of the old carousel bins was also contaminated with ifosfamide. There were no detectable levels of hazardous drugs on any of the new storage bins at time 0, 8 or 16 weeks. However, at the Week 52, there was a detectable level of 5-FU present in the 5-FU carousel bin. Conclusions Contamination of the surrogate markers suggests that external packaging for hazardous drugs is contaminated, either during the manufacturing process or during routine chain of custody activities. These results demonstrate that occupational exposure may occur due to contamination from shipping totes and storage bins, and that handling practices including use of personal protective equipment is warranted.

  10. Assessment of vadose zone radionuclide contamination around Single Shell Tank 241-C-103

    International Nuclear Information System (INIS)

    Kos, S.E.

    1995-12-01

    Five drywells surrounding single shell tank 241-C-103 were logged with the high-purity germanium logging system to investigate possible leakage of radioactive contamination from the tank. The investigation included integration of the drywell survey results with several other data sources. There is no conclusive evidence showing indications that the 241-C-103 tank has leaked

  11. Distribution of contaminants in the occupied zone of a room with personalized and displacement ventilation

    DEFF Research Database (Denmark)

    Cermak, Radim; Melikov, Arsen Krikor; Forejt, L.

    2004-01-01

    A distribution of contaminants from floor covering, exhaled air and human bioeffluents was examined in a mock-up of a typical two-person office by means of tracer-gases. The distribution was studied with two types of air terminal device for personalized ventilation combined with displacement...

  12. Historical and cultural legacy in the Chernobyl contaminated zone: the recommendations for its preservation

    International Nuclear Information System (INIS)

    Filistovich, M.M.

    1995-01-01

    The Chernobyl accident has an effect not only on economics and environment of Belarus. Impact on historical and cultural inheritance of the republic have done. The descriptions of the main archaeological and architectural monuments on the contaminated territory are given. The recommendations for preservation of the historical and cultural inheritance are given for local authorities and state bodies of culture and education

  13. Laboratory Development of Polyphosphate Remediation Technology for In Situ Treatment of Uranium Contamination in the Vadose Zone and Capillary Fringe

    International Nuclear Information System (INIS)

    Wellman, Dawn M.; Pierce, Eric M.; Bovaird, Chase C.; Griswold, Kimberly M.; Gunderson, Katie M.; Webb, Samuel M.; Bargar, John R.

    2009-01-01

    A laboratory testing program has been conducted to optimize polyphosphate remediation technology for implementation through a field-scale technology infiltration demonstration to stabilize soluble, uranium-bearing source phases in the vadose zone and capillary fringe. Source treatment in the deep vadose zone will accelerate the natural attenuation of uranium to more thermodynamically stable uranium-phosphate minerals, enhancing the performance of the proposed polyphosphate remediation within the 300 Area aquifer. The objective of this investigation was to develop polyphosphate remediation technology to treat uranium contamination contained within the deep vadose zone and capillary fringe. This chapter presents the results of an investigation that evaluated the rate and extent of reaction between polyphosphate and the uranium mineral phases present within the 300 Area, and autunite formation as a function of polyphosphate formulation and concentration. This information is critical for identifying the optimum implementation approach and controlling the flux of uranium to the underlying aquifer during remediation. Results from this investigation may be used to design a full-scale remediation of uranium at the 300 Area of the Hanford Site.

  14. Removing device and method for radiation-contaminated concrete surface layer

    International Nuclear Information System (INIS)

    Ida, Kiyoshi.

    1996-01-01

    When a radiation-contaminated concrete surface layer is crushed, peeled or melted, and the products generated by the procedures are captured by sucking, the activity of the products is measured. It is judged whether the result is higher than a predetermined level or not, and when the activity is lowered to a predetermined level or less, the portion to be crushed, peeled or melted is moved and the radiation-contaminated concrete surface layer is thus successively removed. In the device of the present invention, microwave energy, millimeter wave energy, or AC arc plasma is used as an energy irradiation means. With such procedures, the contaminated concrete surface layer can be removed efficiently with neither more nor less. (T.M.)

  15. Integrated modelling for assessing the risk of groundwater contaminants to human health and surface water ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Rasmussen, Jes; Funder, Simon G.

    2010-01-01

    of contamination. In particular, adaptive management tools designed to work with sparse data sets from preliminary site assessments are needed which can explicitly link contaminant point sources with groundwater, surface water and ecological impacts. Here, a novel integrated modelling approach was employed...... volatilisation model for the stream. The model is tested on a Danish case study involving a 750 m long TCE groundwater plume discharging into a stream. The initial modelling results indicate that TCE contaminant plumes with μgL-1 concentrations entering surface water systems do not pose a significant risk...... for evaluating the impact of a TCE groundwater plume, located in an area with protected drinking water interests, to human health and surface water ecosystems. This is accomplished by coupling the system dynamicsbased decision support system CARO-Plus to the aquatic ecosystem model AQUATOX via an analytical...

  16. Effects of surface contamination and cleaning with hypochlorite wipes on the antibacterial activity of copper-alloyed antibacterial stainless steel.

    Science.gov (United States)

    Kawakami, Hiroshi; Hayashi, Takatsuna; Nishikubo, Hideyuki; Morikawa, Akifumi; Suzuki, Satoshi; Sato, Yoshihiro; Kikuchi, Yasushi

    2014-01-01

    Effects of surface contamination and cleaning with hypochlorite wipes on the antibacterial activity of copper-alloyed stainless steel were studied. The antibacterial activity of copper alloyed stainless steel decreased with the increase in the amount of surface contaminant, and the bacterial counts from specimens contaminated with a contaminant, e.g. 1.6 × 10(-2) μg/mm(2) of bovine serum albumin, were not significantly different from those from ordinary stainless steel specimens. The once contaminated surface could regain its antibacterial activity when it was sufficiently wiped clean with sterile wipes loaded with sodium hypochlorite solution.

  17. Development of the automatic measuring system to survey the surface contamination on equipments

    International Nuclear Information System (INIS)

    Ishizuka, Akira; Matsumura, Hidekatsu; Nawa, Takao; Yamaguchi, Seiji; Yamada, Tadashi.

    1980-01-01

    The inspection of surface contamination carried out when things are taken out of the control areas in nuclear power stations requires considerable labor and time because it is carried out manually. In order to make the inspection of surface contamination more efficiently and to standardize it, the development of an automatic inspection apparatus was carried out. This apparatus inspects the surface contamination due to radio isotopes which do not emit α-ray, and the objects to be measured are the large things with definite forms, such as boards and pipes for scaffolding. The method of measuring β-ray with a gas flow counter was adopted for the apparatus in view of the good detection sensitivity, relatively simple shielding against background, and easy conversion to surface contamination density. The measuring system was composed of the gas flow counters and a rate meter. The outline of the apparatus made for trial is explained. As the result of the performance test, the lowest detection sensitivity was 1.29 x 10 -5 μCi/cm 2 at the moving speed of an object of 1 cm/sec. The detection sensitivity is improved by the flattening of the sensitivity distribution. The evaluation of the error, the reduction of measuring time and the prevention of contamination were also made. (Kako, I.)

  18. Phytoremediation potential of weeds in heavy metal contaminated soils of the Bassa Industrial Zone of Douala, Cameroon.

    Science.gov (United States)

    Lum, A Fontem; Ngwa, E S A; Chikoye, D; Suh, C E

    2014-01-01

    Phytoremediation is a promising option for reclaiming soils contaminated with toxic metals, using plants with high potentials for extraction, stabilization and hyperaccumulation. This study was conducted in Cameroon, at the Bassa Industrial Zone of Douala in 2011, to assess the total content of 19 heavy metals and 5 other elements in soils and phytoremediation potential of 12 weeds. Partial extraction was carried out in soil, plant root and shoot samples. Phytoremediation potential was evaluated in terms of the Biological Concentration Factor, Translocation Factor and Biological Accumulation Coefficient. The detectable content of the heavy metals in soils was Cu:70-179, Pb:8-130, Zn:200-971, Ni:74-296, Co:31-90, Mn:1983-4139, V:165-383, Cr:42-1054, Ba:26-239, Sc:21-56, Al:6.11-9.84, Th:7-22, Sr:30-190, La:52-115, Zr:111-341, Y:10-49, Nb:90-172 in mg kg(-1), and Ti:2.73-4.09 and Fe:12-16.24 in wt%. The contamination index revealed that the soils were slightly to heavily contaminated while the geoaccumulation index showed that the soils ranged from unpolluted to highly polluted. The concentration of heavy metals was ranked as Zn > Ni > Cu > V > Mn > Sc > Co > Pb and Cr in the roots and Mn > Zn > Ni > Cu > Sc > Co > V > Pb > Cr > Fe in the shoots. Dissotis rotundifolia and Kyllinga erecta had phytoextraction potentials for Pb and Paspalum orbicularefor Fe. Eleusine indica and K. erecta had phytostabilisation potential for soils contaminated with Cu and Pb, respectively.

  19. Hygienic aspects of safety vital activity support of servicemen and their families on the contaminated zone

    International Nuclear Information System (INIS)

    Greben'kov, S.V.; Zholus, B.I.

    1996-01-01

    Analysis of radiation-and-hygienic, radioecological and medical aspects of vital activity of servicemen and their families at the radioactive contaminated territories (RCT) after the Chernobyl NPP accident has shown that the life there is linked with the increased health risk. The paper presents the examination results of 2550 human beings, over 2100 samples of foods and of the environmental objects have been examined. The direct correlation link between the territory contamination density and Cs-137 content in foods was determined; additional radiation burden from foods through gastrointestinal tract was observed in case of the incorporated radiation of a human being. The values of dose radiation burden of the examined persons during their life at the RCT were estimated. The life at the RCT is linked with the morbidity,with growth of psychonoses, with the rearrangement of the immune system. 10 refs

  20. Phytoplankton pigments from the Nimbus-7 Coastal Zone Color Scanner - Comparisons with surface measurements

    Science.gov (United States)

    Gordon, H. R.; Clark, D. K.; Hovis, W. A.; Mueller, J. L.

    1980-01-01

    Algorithms are developed for removing aerosol effects in visual data from the Nimbus-7 Coastal Zone Color Scanner (CZCS). The corrected imagery reveals eddy-like ocean circulation patterns. Pigment concentrations from CZCS are compared with surface determinations. CZCS imagery estimates pigment concentration to within 0.5 log C, where C is the sum of the concentrations of chlorophyll a and phaeopigments a

  1. Laboratory Column Studies to Evaluate the use of pH Triggered Polymers for Hydraulically Isolating Contaminated Vadose Zone Sediments and Perched Water Zones

    Science.gov (United States)

    Baker, K.

    2006-12-01

    Laboratory studies were conduced to evaluate the use of polyacrylic polymers to hydraulically isolate contaminants in vadose zone saturated and unsaturated geologic materials. Similar polymers have been successfully used in the petroleum industry for analogous applications, but this technology has not been applied to environmental remediation activities. Polymers are capable of swelling thousands of times their original size when triggered by changes in pH and ionic strength while exhibiting a very low permeability. Therefore, polymers have the potential to significantly reduce permeability of geologic media, redirecting water infiltration away from contaminated regions of the subsurface. These polymers are polyacrylic acids that when mixed with water, exhibit initial fluid properties similar to water at pH between 2.0 4.0. The solutions are introduced into geologic materials where the acidic solution reacts with the minerals and in situ pore water, altering the pH and the ionic strength of the solution. These changes trigger an increase in solution viscosity as the polymers swell, plugging pores and reducing permeability. The polymer kinetics of these reactions are controlled by the geologic mineralogy, solution flux rate, polymer concentrations, and solvent chemistry. Researchers at the Idaho National Laboratory Research Center evaluated field emplacement methods that impact polymer rheology kinetics by conducting soil batch experiments and column studies with two commercially available polymers. The researchers were able to identify appropriate polymer and solvent concentrations, solution flux rates, and reaction times required to significantly reduce soil permeability. This poster presentation will present the laboratory methods developed to evaluate the use of polymers for environmental remediation activities and results of these tests.

  2. Microstructural and geochemical evolution of sliding surfaces in landslides and comparisons with crustal fault zones

    Science.gov (United States)

    Schäbitz, Maike; Janssen, Christoph; Wirth, Richard; Dresen, Georg

    2015-04-01

    The formation of basal sliding surfaces in mass movements is known to be associated with chemical and physical alteration of rock and regolith. To evaluate their microstructural and geochemical evolution we collected samples from bedrock, the sliding surface (gouge) and adjacent deposits within two different landslides in Central China. The sample locations reflect different geological conditions. Comparing qualitative and quantitative geochemical analysis we found indications for weathering of the sliding surface area and the accumulation and genesis of clay minerals, explaining its reduced shear strength. The cataclasites (gouge) are mainly composed of quartz, illite, calcite, pyrophyllite, kaolinite and feldspar with grain sizes in the range 0.5 - 5μm. XRF data show an increase in Al2O3, Fe2O3, K2O and decrease in SiO2 and CaO contents towards the sliding surface, pointing to alteration processes. The existence and increase of pyrophyllite content in sliding surface samples may indicate its initial formation to be caused by a high energy event, because pyrophyllite forms by hydrothermal alteration at approximately 450 ° C. The accumulation of pyrophyllite at the sliding surface is expected to result in reduced shear strength. Comparison of the microstructures, using transmission electron microscopy and focused ion beam technique for sample preparation shows a significant reduction of grain size and increase of pore space due to grain comminution by creeping and moving processes. High- angle annular dark field images show the occurrence of amorphous carbon which may indicate the occurrence of graphite. Graphitization (crystallization) of amorphous carbon was recognized in the slip zone of several fault zones, which underwent frictional heating due to rapid sliding. Graphite is well known as a solid lubricant in fault zones with a friction coefficient as low as that of smectite (μ = 0.1). The process of sliding surface formation in some landslides seems to be

  3. Derived surface contamination limits for the uranium mining and milling industry

    International Nuclear Information System (INIS)

    Ching, S.H.

    1984-10-01

    Derived Surface Contamination Limits (DSCL) are proposed for the control of surface contamination at the work place for the uranium mining and milling industry. They have been derived by a method incorporating recent ICRP recommendations and consideration of the radiation exposure pathways of ingestion, inhalation and external irradiation of the basal layer of skin. A generalized DSCL of 10 5 Bq/m 2 of beta activity is recommended for all contaminants likely to be found in uranium mine and mill workplaces except for fresh uranium concentrates. In the latter case, the DSCL is expressed in terms of alpha activity because the ratio of beta to alpha activities for fresh uranium concentrates is variable; the beta activity increases with the ingrowth of U-238 daughter products (Th-234 and Pa-234m) until secular equilibrium is re-established in about six months. A surface contamination limit of 10 4 Bq/m 2 of beta activity is proposed for the release of non-porous materials and equipment with no detectable loose contamination to the public domain

  4. Sub-soil contamination due to oil spills in zones surrounding oil pipeline-pump stations and oil pipeline right-of-ways in Southwest-Mexico.

    Science.gov (United States)

    Iturbe, Rosario; Flores, Carlos; Castro, Alejandrina; Torres, Luis G

    2007-10-01

    Oil spills due to oil pipelines is a very frequent problem in Mexico. Petroleos Mexicanos (PEMEX), very concerned with the environmental agenda, has been developing inspection and correction plans for zones around oil pipelines pumping stations and pipeline right-of-way. These stations are located at regular intervals of kilometres along the pipelines. In this study, two sections of an oil pipeline and two pipeline pumping stations zones are characterized in terms of the presence of Total Petroleum Hydrocarbons (TPHs) and Polycyclic Aromatic Hydrocarbons (PAHs). The study comprehends sampling of the areas, delimitation of contamination in the vertical and horizontal extension, analysis of the sampled soils regarding TPHs content and, in some cases, the 16 PAHs considered as priority by USEPA, calculation of areas and volumes contaminated (according to Mexican legislation, specifically NOM-EM-138-ECOL-2002) and, finally, a proposal for the best remediation techniques suitable for the contamination levels and the localization of contaminants.

  5. Evaluation of surface water and groundwater contamination in a MSW landfill area using hydrochemical analysis and electrical resistivity tomography: a case study in Sichuan province, Southwest China.

    Science.gov (United States)

    Ling, Chengpeng; Zhang, Qiang

    2017-04-01

    As a primary disposal mean of municipal solid waste in China, the landfill has been recognized as one of the major threats to the surrounding surface water and groundwater environment due to the emission of leachate. The aim of this study was to determine the impact of leachate on the surface water and groundwater environment of the region of the Chang'an landfill, which is located in Sichuan province, China. The surface water and groundwater were sampled for hydrochemical analysis. Three electrical resistivity tomography profiles were conducted to evaluate the impact of leachate on the groundwater environment, and several laboratory tests were carried out to build the relationship between the soil bulk resistivity and the void fluid resistivity. The results showed that a seasonal creek named Longfeng creek, which crosses the landfill site, was contaminated by the leachate. The concentrations of COD, BOD5, and chlorides (Cl) of surface water samples increased by 12.3-105.7 times. The groundwater quality in the surface loose sediments along the valley deteriorated obviously from the landfill to 500 m downstream area. The laboratory tests of soil samples indicated that the resistivity value of 13 Ωm is a critical value whether the groundwater in the loose sediments is polluted. The groundwater at the site adjacent to the spillway in the landfill was partially contaminated by the emission of leachate. The groundwater contamination zones at 580 m downstream of the landfill were recognized at the shallow zones from 60 m left bank to 30 m right bank of Longfeng creek. The improved understanding of groundwater contamination around the landfill is beneficial for the landfill operation and groundwater environment remediation.

  6. Experimental analysis on removal factor of smear method in measurement of surface contamination

    International Nuclear Information System (INIS)

    Sugiura, Nobuyuki; Taira, Junichi; Takenaka, Keisuke; Yamanaka, Kazuo; Sugai, Kenji; Kosako, Toshiso

    2007-01-01

    The smear test is one of the important ways to measure surface contamination. The loose contamination under the high background radiation, which is more significant in handling non-sealed radioisotopes, can be evaluated by this method. The removal factor is defined as the ratio of the activity removed from the surface by one smear to the whole activity of the removable surface contamination. The removal factor is greatly changed by the quality and condition of surface materials. In this study, the values of removal factor at several typical surface conditions were evaluated experimentally and the practical application of those values was considered. It is required the smear should be pressed by moderate pressure when wiping the surface. The pressure from 1.0 kg to 1.5 kg per filter paper was recommended. The removal factor showed lower value in wiping by the pressure below 1.0 kg. The value of 0.5 for the removal factor could be applied to the smooth surface of linoleum, concrete coated with paint or epoxy resin, stainless steel and glass with the statistical allowance. (author)

  7. IDENTIFICATION OF DANGER ZONES FOR SURFACE WATER USING GIS (SIP – MAPINFO SYSTEM ON AN EXAMPLE OF UPPER NAREW RIVER CATCHMENT

    Directory of Open Access Journals (Sweden)

    Mirosław Skorbiłowicz

    2016-07-01

    Full Text Available Creating the buffer zones is a function intended to designate an area in particular, of a constant distance around the spatial objects. The aim of the study was to create maps as thematic layers, which served to identify areas of existing and potential contamination of surface water and other environmental elements. Among others, it made possible to localize the areas potentially affected by the surface water pollution due to transport; localize the areas potentially affected by the surface water pollution due to the discharge of sewage from human settlements; localize the zones with mitigated impact of communication emissions due to the natural protection of forests taking the form of so-called geochemical barriers. The spatial analyzes allowed to generate model-zones of the existing and potential threat of water pollution in the Narew river catchment. Designated danger zones can be verified by studies as well as they can be very helpful in determining the monitoring network and for water quality modeling process.

  8. N.V. Timofeev-Resovsky's ideas in present studies of radioactive contamination zones of the Urals

    International Nuclear Information System (INIS)

    Molchanova, I.V.; Pozolotina, V.N.; Karavaeva, E.N.; Antonova, E.V.; Mikhaylovskaya, L.N.

    2008-01-01

    The theory of living substance and the Earth biosphere by the brilliant Russian scientist V.I. Vernadsky has produced a great world view effect. Basing on this theory another prominent Russian researcher N.V. Timofeev-Resovsky came up to formation of a new scientific discipline - radioecology. He identified two basic areas of research in radioecology (radiation biocenology): 1) studies of the radionuclide fate in natural ecosystems and 2) assessment of biological effects of ionizing radiation on living organisms, population, ecosystems. In our research activities conducted in the East Uralian Radioactive Trail (EURT) zone resulted from an accident at the Mayak concern in 1957, we attempted to advance some ideas of Timofeev-Resovsky (1957). The objectives of research were to assess recent levels and distribution of radio-nuclides between ecosystem components along the contamination gradient and 2) to study effects of low levels of chronic radiation exposure on populations of herbaceous plants (author)(tk)

  9. On the problem of social-psychological state of children in contaminated zones

    International Nuclear Information System (INIS)

    Linge, I.I.; Tarasov, V.I.; Klement'eva, A.Ya.; Barklyanskij, Yh.A.

    1993-01-01

    The paper presents the results of investigation into clash situation characteristic of senior pupils (9-11-th classes) living at the radioactive contamination areas and in clean areas located in 5 regions of Russia: the Bryansk, the Kaluga, the Orel, the Smolensk and the Tula regions. The data analysis enabled to separate three special groups among children in eight-dimension characteristic space of the clash situation: 1 guilt; 2 loyal; 3 conflict ones. The resident area is shown to have insignificant discriminant feature at description of the indicated groups

  10. Studies of radionuclides behavior on heavily contaminated 5-km zone of СhNPP

    Directory of Open Access Journals (Sweden)

    D. M. Bondarkov

    2016-12-01

    Full Text Available Studies of the radionuclides behavior in the soils of “Red Forest” landfill in the nearest 5-km ChNPP zone were carried out during 2014 - 2015. The parameters of vertical migration and halftimes of upper 5-cm soil layer decontamination were obtained. Forms of occurrence of 90Sr and 137Cs, as well as the disperse composition of the Chernobyl origin fuel particles were evaluated. Behavior of radionuclides described in conditions of the convection-diffusion model and the parameters of the model slightly changed over the past decade.

  11. THE AVERAGE ANNUAL EFFECTIVE DOSES FOR THE POPULATION IN THE SETTLEMENTS OF THE RUSSIAN FEDERATION ATTRIBUTED TO ZONES OF RADIOACTIVE CONTAMINATION DUE TO THE CHERNOBYL ACCIDENT (FOR ZONATION PURPOSES, 2014

    Directory of Open Access Journals (Sweden)

    G. Ja. Bruk

    2015-01-01

    Full Text Available The Chernobyl accident in 1986 is one of the most large-scale radiation accidents in the world. It led to radioactive contamination of large areas in the European part of the Russian Federation and at the neighboring countries. Now, there are more than 4000 settlements with the total population of 1.5 million in the radioactively contaminated areas of the Russian Federation. The Bryansk region is the most intensely contaminated region. For example, the Krasnogorskiy district still has settlements with the level of soil contamination by cesium-137 exceeding 40 Cu/km2. The regions of Tula, Kaluga and Orel are also significantly affected. In addition to these four regions, there are 10 more regions with the radioactively contaminated settlements. After the Chernobyl accident, the affected areas were divided into zones of radioactive contamination. The attribution of the settlements to a particular zone is determined by the level of soil contamination with 137Cs and by a value of the average annual effective dose that could be formed in the absence of: 1 active measures for radiation protection, and 2 self-limitation in consumption of the local food products. The main regulatory document on this issue is the Federal law № 1244-1 (dated May, 15,1991 «On the social protection of the citizens who have been exposed to radiation as a result of the accident at the Chernobyl nuclear power plant». The law extends to the territories, where, since 1991: – The average annual effective dose for the population exceeds 1 mSv (the value of effective dose that could be formed in the absence of active radiation protection measures and self-limitation in consumption of the local food products; – Soil surface contamination with cesium-137 exceeds 1 Cu/km2. The paper presents results of calculations of the average effective doses in 2014. The purpose was to use the dose values (SGED90 in zonation of contaminated territories. Therefore, the

  12. THE AVERAGE ANNUAL EFFECTIVE DOSES FOR THE POPULATION OF THE SETTLEMENTS OF THE RUSSIAN FEDERATION ATTRIBUTED TO ZONES OF RADIOACTIVE CONTAMINATION DUE TO THE CHERNOBYL ACCIDENT (FOR THE ZONATION PURPOSES, 2017

    Directory of Open Access Journals (Sweden)

    G. Ya. Bruk

    2017-01-01

    Full Text Available The Chernobyl accident in 1986 is one of the most large-scale radiation accidents in the world. It led to radioactive contamination of large areas in the European part of the Russian Federation and at the neighboring countries. Now, there are more than 4000 settlements with the total population of 1.5 million in the radioactively contaminated areas of the Russian Federation. The Bryansk region is the most intensely contaminated region. For example, the Krasnogorskiy district still has settlements with the level of soil contamination by cesium-137 exceeding 40 Ci/km2. The regions of Tula, Kaluga and Orel are also significantly affected. In addition to these four regions, there are ten more regions with the radioactively contaminated settlements. After the Chernobyl accident, the affected areas were divided into zones of radioactive contamination. The attribution of the settlements to a particular zone is determined by the level of soil contamination with 137Cs and by a value of the average annual effective dose that could be formed in the absence of: 1 active measures for radiation protection, and 2 self-limitation in consumption of the local food products. The main regulatory document on this issue is the Federal law № 1244-1 (dated May, 15 1991 “On the social protection of the citizens who have been exposed to radiation as a result of the accident at the Chernobyl nuclear power plant”. The law extends to the territories, where, since 1991: 1 the average annual effective dose for the population exceeds 1 mSv (the value of effective dose that could be formed in the absence of active radiation protection measures and self-limitation in consumption of the local food products; 2 soil surface contamination with cesium-137 exceeds 1 Ci/km2.The paper presents results of calculations of the average effective doses in 2017. The purpose was to use the dose values (SGED90 in zonation of contaminated territories. Therefore, the calculations have been

  13. Effectiveness of disinfection with alcohol 70% (w/v) of contaminated surfaces not previously cleaned

    OpenAIRE

    Graziano, Maurício Uchikawa; Graziano, Kazuko Uchikawa; Pinto, Flávia Morais Gomes; Bruna, Camila Quartim de Moraes; Souza, Rafael Queiroz de; Lascala, Cesar Angelo

    2013-01-01

    OBJECTIVE: To evaluate the disinfectant effectiveness of alcohol 70% (w/v) using friction, without previous cleaning, on work surfaces, as a concurrent disinfecting procedure in Health Services. METHOD: An experimental, randomized and single-blinded laboratory study was undertaken. The samples were enamelled surfaces, intentionally contaminated with Serratia marcescens microorganisms ATCC 14756 106 CFU/mL with 10% of human saliva added, and were submitted to the procedure of disinfection W...

  14. Investigation of the pathway of contaminated soil transported to plant surfaces by raindrop splash

    International Nuclear Information System (INIS)

    Dreicer, M.; Hakonson, T.E.; Whicker, F.W.; White, G.C.

    1983-01-01

    The environmental transport pathway of soil-borne radioisotopes to vegetation surfaces via raindrop splash was studied. The data show that soil can significantly contribute to the contamination found on plants. Further detailed study is needed to calculate the rate constant for the raindrop splash and retention pathways. 8 references, 1 figure

  15. Cold plasma rapid decontamination of food contact surfaces contaminated with Salmonella biofilms

    Science.gov (United States)

    Cross-contamination of fresh produce and other foods from persistent pathogen reservoirs is a known risk factor in processing environments. Industry requires a rapid, waterless, zero-contact, chemical-free method for removing pathogens from food-contact surfaces. Cold plasma was tested for its abili...

  16. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    DEFF Research Database (Denmark)

    Furuse, Adilson Yoshio; da Cunha, Leonardo Fernandes; Benetti, Ana Raquel

    2007-01-01

    of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin...

  17. A new technique for the identification of surface contamination in low temperature bolometric experiments

    International Nuclear Information System (INIS)

    Sangiorgio, S.; Arnaboldi, C.; Brofferio, C.; Bucci, C.; Capelli, S.; Carbone, L.; Clemenza, M.; Cremonesi, O.; Fiorini, E.; Foggetta, L.; Giuliani, A.; Gorla, P.; Nones, C.; Nucciotti, A.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Previtali, E.; Salvioni, C.

    2011-01-01

    In the framework of the bolometric experiment CUORE, a new and promising technique has been developed in order to control the dangerous contamination coming from the surfaces close to the detector. In fact, by means of a composite bolometer, it is possible to partially overcome the loss of spatial resolution of the bolometer itself and to clearly identify events coming from outside.

  18. Aluminum-contaminant transport by surface runoff and bypass flow from an acid sulphate soil

    NARCIS (Netherlands)

    Minh, L.Q.; Tuong, T.P.; Mensvoort, van M.E.F.; Bouma, J.

    2002-01-01

    Quantifying the process and the amount of acid-contaminant released to the surroundings is important in assessing the environmental hazards associated with reclaiming acid sulphate soils (ASS). The roles of surface runoff and bypass flow (i.e. the rapid downward flow of free water along macropores

  19. Zero-tension lysimeters: An improved design to monitor colloid-facilitated contaminant transport in the vadose zone

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, M.L.; Scharf, R.L.; Shang, C.

    1995-04-24

    There is increasing evidence that mobile colloids facilitate the long-distance transport of contaminants. The mobility of fine particles and macromolecules has been linked to the movement of actinides, organic contaminants, and heavy metals through soil. Direct evidence for colloid mobility includes the presence of humic materials in deep aquifers as well as coatings of accumulated clay, organic matter, or sesquioxides on particle or aggregate surfaces in subsoil horizons of many soils. The potential for colloid-facilitated transport of contaminants from hazardous-waste sites requires adequate monitoring before, during, and after in-situ remediation treatments. Zero-tension lysimeters (ZTLs) are especially appropriate for sampling water as it moves through saturated soil, although some unsaturated flow events may be sampled as well. Because no ceramic barrier or fiberglass wick is involved to maintain tension on the water (as is the case with other lysimeters), particles suspended in the water as well as dissolved species may be sampled with ZTLs. In this report, a ZTL design is proposed that is more suitable for monitoring colloid-facilitated contaminant migration. The improved design consists of a cylinder made of polycarbonate or polytetrafluoroethylene (PTFE) that is placed below undisturbed soil material. In many soils, a hydraulically powered tube may be used to extract an undisturbed core of soil before placement of the lysimeter. In those cases, the design has significant advantages over conventional designs with respect to simplicity and speed of installation. Therefore, it will allow colloid-facilitated transport of contaminants to be monitored at more locations at a given site.

  20. Zero-tension lysimeters: An improved design to monitor colloid-facilitated contaminant transport in the vadose zone

    International Nuclear Information System (INIS)

    Thompson, M.L.; Scharf, R.L.; Shang, C.

    1995-01-01

    There is increasing evidence that mobile colloids facilitate the long-distance transport of contaminants. The mobility of fine particles and macromolecules has been linked to the movement of actinides, organic contaminants, and heavy metals through soil. Direct evidence for colloid mobility includes the presence of humic materials in deep aquifers as well as coatings of accumulated clay, organic matter, or sesquioxides on particle or aggregate surfaces in subsoil horizons of many soils. The potential for colloid-facilitated transport of contaminants from hazardous-waste sites requires adequate monitoring before, during, and after in-situ remediation treatments. Zero-tension lysimeters (ZTLs) are especially appropriate for sampling water as it moves through saturated soil, although some unsaturated flow events may be sampled as well. Because no ceramic barrier or fiberglass wick is involved to maintain tension on the water (as is the case with other lysimeters), particles suspended in the water as well as dissolved species may be sampled with ZTLs. In this report, a ZTL design is proposed that is more suitable for monitoring colloid-facilitated contaminant migration. The improved design consists of a cylinder made of polycarbonate or polytetrafluoroethylene (PTFE) that is placed below undisturbed soil material. In many soils, a hydraulically powered tube may be used to extract an undisturbed core of soil before placement of the lysimeter. In those cases, the design has significant advantages over conventional designs with respect to simplicity and speed of installation. Therefore, it will allow colloid-facilitated transport of contaminants to be monitored at more locations at a given site

  1. 30 CFR 761.15 - Procedures for waiving the prohibition on surface coal mining operations within the buffer zone...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Procedures for waiving the prohibition on surface coal mining operations within the buffer zone of an occupied dwelling. 761.15 Section 761.15... surface coal mining operations within the buffer zone of an occupied dwelling. (a) This section does not...

  2. Evaluation of the contamination by stable and unstable isotopes in the coastal zones associated to hydrographic basins of Costa Rica

    International Nuclear Information System (INIS)

    Loria Meneses, Luis Guillermo; Lizano Rodriguez, Omar G.; Salazar Matarrita, Alfonso; Jimenez Dam, Ricardo

    2003-01-01

    The degree of contamination by the stable and unstable isotopes concentration in sediments of beaches of Costa Rica is evaluated. It establishes relations between the trace elements in sediments from beaches not associated to hydrographic basins and associated sediments to basins. The totality of sediments coming of beaches were analyzed by the technique of gamma spectroscopy and x-rays spectroscopy. It was determined that the beaches associated to bays and gulfs present greater concentrations as for the presence of radioactive isotopes. In addition, the existing concentrations for unstable isotopes present low values in the zones of open sea; whereas the values of radiation background in beaches and gulfs allow, to future, to detect if is presenting anthropogenic contamination of origin in that type of isotopes or could be a greater presence of these. The obtained results show that the values of radiation of background in beaches were unknown, as well as the unstable isotopes concentration. Also was found the presence of Cs 137, which comes normally from nuclear blasts. The work already includes two published documents [es

  3. Influence of Wetting and Mass Transfer Properties of Organic Chemical Mixtures in Vadose Zone Materials on Groundwater Contamination by Nonaqueous Phase Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Charles J Werth; Albert J Valocchi, Hongkyu Yoon

    2011-05-21

    Previous studies have found that organic acids, organic bases, and detergent-like chemicals change surface wettability. The wastewater and NAPL mixtures discharged at the Hanford site contain such chemicals, and their proportions likely change over time due to reaction-facilitated aging. The specific objectives of this work were to (1) determine the effect of organic chemical mixtures on surface wettability, (2) determine the effect of organic chemical mixtures on CCl4 volatilization rates from NAPL, and (3) accurately determine the migration, entrapment, and volatilization of organic chemical mixtures. Five tasks were proposed to achieve the project objectives. These are to (1) prepare representative batches of fresh and aged NAPL-wastewater mixtures, (2) to measure interfacial tension, contact angle, and capillary pressure-saturation profiles for the same mixtures, (3) to measure interphase mass transfer rates for the same mixtures using micromodels, (4) to measure multiphase flow and interphase mass transfer in large flow cell experiments, all using the same mixtures, and (5) to modify the multiphase flow simulator STOMP in order to account for updated P-S and interphase mass transfer relationships, and to simulate the impact of CCl4 in the vadose zone on groundwater contamination. Results and findings from these tasks and summarized in the attached final report.

  4. A new cleaning process for the metallic contaminants on a post-CMP wafer's surface

    International Nuclear Information System (INIS)

    Gao Baohong; Liu Yuling; Wang Chenwei; Wang Shengli; Zhou Qiang; Tan Baimei; Zhu Yadong

    2010-01-01

    This paper presents a new cleaning process using boron-doped diamond (BDD) film anode electrochemical oxidation for metallic contaminants on polished silicon wafer surfaces. The BDD film anode electrochemical oxidation can efficiently prepare pyrophosphate peroxide, pyrophosphate peroxide can oxidize organic contaminants, and pyrophosphate peroxide is deoxidized into pyrophosphate. Pyrophosphate, a good complexing agent, can form a metal complex, which is a structure consisting of a copper ion, bonded to a surrounding array of two pyrophosphate anions. Three polished wafers were immersed in the 0.01 mol/L CuSO 4 solution for 2 h in order to make comparative experiments. The first one was cleaned by pyrophosphate peroxide, the second by RCA (Radio Corporation of America) cleaning, and the third by deionized (DI) water. The XPS measurement result shows that the metallic contaminants on wafers cleaned by the RCA method and by pyrophosphate peroxide is less than the XPS detection limits of 1 ppm. And the wafer's surface cleaned by pyrophosphate peroxide is more efficient in removing organic carbon residues than RCA cleaning. Therefore, BDD film anode electrochemical oxidation can be used for microelectronics cleaning, and it can effectively remove organic contaminants and metallic contaminants in one step. It also achieves energy saving and environmental protection. (semiconductor technology)

  5. Surface Contaminant Control Technologies to Improve Laser Damage Resistance of Optics

    Directory of Open Access Journals (Sweden)

    Xiaofeng Cheng

    2014-01-01

    Full Text Available The large high-power solid lasers, such as the National Ignition Facility (NIF of America and the Shenguang-III (SG-III laser facility of China, can output over 2.1 MJ laser pulse for the inertial confinement fusion (ICF experiments. Because of the enhancement of operating flux and the expansion of laser driver scale, the problem of contamination seriously influences their construction period and operation life. During irradiation by intense laser beams, the contaminants on the metallic surface of beam tubes can be transmitted to the optical surfaces and lead to damage of optical components. For the high-power solid-state laser facilities, contamination control focuses on the slab amplifiers, spatial filters, and final-optical assemblies. In this paper, an effective solution to control contaminations including the whole process of the laser driver is put forward to provide the safe operation of laser facilities, and the detailed technical methods of contamination control such as washing, cleanliness metrology, and cleanliness protecting are also introduced to reduce the probability of laser-induced damage of optics. The experimental results show that the cleanliness level of SG-III laser facility is much better to ensure that the laser facility can safely operate at high energy flux.

  6. Determination of Spatial Chromium Contamination of the Environment around Industrial Zones

    Science.gov (United States)

    Homa, Dereje; Haile, Ermias

    2016-01-01

    This study was conducted to determine the spatial levels of chromium contamination of water, agricultural soil, and vegetables in the leather tanning industrial areas using spectrophotometric methods. The results showed elevated accumulation of total Cr ranging from 10.85 ± 0.885 mg/L to 39.696 ± 0.326 mg/L, 16.225 ± 0.12 mg/Kg to 1581.667 ± 0.122 mg/Kg, and 1.0758 ± 0.05348 mg/Kg to 11.75 ± 0.206 mg/Kg in water, agricultural soil, and vegetable samples, respectively. The highest levels of chromium (VI) found from the speciation study were 2.23 ± 0.032 mg/Kg and 0.322 ± 0.07 mg/L in soil and water samples, respectively, which decreased with distance from the tannery. Among the vegetables, the highest load of Cr(VI) was detected in onion root (0.048 ± 0.065 mg/Kg) and the lowest (0.004 ± 0.007 mg/Kg) in fruit of green pepper. The detected levels of Cr in all of the suggested samples were above the WHO permissible limits. The variations of the levels Cr(III) and Cr(VI) contamination of the environment with distance from the tannery were statistically significant (p = 0.05). Similarly, significant difference in the levels of Cr among the tested vegetables was recorded. The levels increased with decreasing distance from the effluent channel. PMID:28044079

  7. Determination of Spatial Chromium Contamination of the Environment around Industrial Zones

    Directory of Open Access Journals (Sweden)

    Dereje Homa

    2016-01-01

    Full Text Available This study was conducted to determine the spatial levels of chromium contamination of water, agricultural soil, and vegetables in the leather tanning industrial areas using spectrophotometric methods. The results showed elevated accumulation of total Cr ranging from 10.85±0.885 mg/L to 39.696±0.326 mg/L, 16.225±0.12 mg/Kg to 1581.667±0.122 mg/Kg, and 1.0758±0.05348 mg/Kg to 11.75±0.206 mg/Kg in water, agricultural soil, and vegetable samples, respectively. The highest levels of chromium (VI found from the speciation study were 2.23±0.032 mg/Kg and 0.322±0.07 mg/L in soil and water samples, respectively, which decreased with distance from the tannery. Among the vegetables, the highest load of Cr(VI was detected in onion root (0.048±0.065 mg/Kg and the lowest (0.004±0.007 mg/Kg in fruit of green pepper. The detected levels of Cr in all of the suggested samples were above the WHO permissible limits. The variations of the levels Cr(III and Cr(VI contamination of the environment with distance from the tannery were statistically significant (p=0.05. Similarly, significant difference in the levels of Cr among the tested vegetables was recorded. The levels increased with decreasing distance from the effluent channel.

  8. GWSCREEN: A Semi-analytical Model for Assessment of the Groundwater Pathway from Surface or Buried Contamination, Theory and User's Manual, Version 2.5

    Energy Technology Data Exchange (ETDEWEB)

    Rood, Arthur South

    1998-08-01

    GWSCREEN was developed for assessment of the groundwater pathway from leaching of radioactive and non-radioactive substances from surface or buried sources. The code was designed for implementation in the Track I and Track II assessment of Comprehensive Environmental Response, Compensation, and Liability Act sites identified as low probability hazard at the Idaho National Engineering Laboratory. The code calculates 1) the limiting soil concentration such that, after leaching and transport to the aquifer regulatory contaminant levels in groundwater are not exceeded, 2) peak aquifer concentration and associated human health impacts, and 3) aquifer concentrations and associated human health impacts as a function of time and space. The code uses a mass conservation approach to model three processes: contaminant release from a source volume, vertical contaminant transport in the unsaturated zone, and 2D or 3D contaminant transport in the saturated zone. The source model considers the sorptive properties and solubility of the contaminant. In Version 2.5, transport in the unsaturated zone is described by a plug flow or dispersive solution model. Transport in the saturated zone is calculated with a semi-analytical solution to the advection dispersion equation in groundwater. Three source models are included; leaching from a surface or buried source, infiltration pond, or user-defined arbitrary release. Dispersion in the aquifer may be described by fixed dispersivity values or three, spatial-variable dispersivity functions. Version 2.5 also includes a Monte Carlo sampling routine for uncertainty/sensitivity analysis and a preprocessor to allow multiple input files and multiple contaminants to be run in a single simulation. GWSCREEN has been validated against other codes using similar algorithms and techniques. The code was originally designed for assessment and screening of the groundwater pathway when field data are limited. It was intended to simulate relatively simple

  9. Estimating fate and transport of multiple contaminants in the vadose zone using a multi-layered soil column and three-phase equilibrium partitioning model

    International Nuclear Information System (INIS)

    Rucker, Gregory G.

    2007-01-01

    Soils at waste sites must be evaluated for the potential of residual soil contamination to leach and migrate to the groundwater beneath the disposal area. If migration to the aquifer occurs, contaminants can travel vast distances and pollute drinking water wells, thus exposing human receptors to harmful levels of toxins and carcinogens. To prevent groundwater contamination, a contaminant fate and transport analysis is necessary to assess the migration potential of residual soil contaminants. This type of migration analysis is usually performed using a vadose zone model to account for complex geotechnical and chemical variables including: decay processes, infiltration rate, soil properties, vadose zone thickness, and chemical behavior. The distinct advantage of using a complex model is that less restrictive, but still protective, soil threshold levels may be determined avoiding the unnecessary and costly remediation of marginally contaminated soils. However, the disadvantage of such modeling is the additional cost for data collection and labor required to apply these models. In order to allay these higher costs and to achieve a less restrictive but still protective clean-up level, a multiple contaminant and multi layered soil column equilibrium partitioning model was developed which is faster, simpler and less expensive to use. (authors)

  10. Geohydrology and susceptibility of major aquifers to surface contamination in Alabama; area 11

    Science.gov (United States)

    Castleberry, R.D.; Moreland, R.S.; Scott, J.C.

    1989-01-01

    This report delineates and describes the geohydrology and susceptibility of major aquifers to contamination in Butler, Conecuh, Covington, Crenshaw, Escambia, and Monroe Counties, Alabama. The major aquifers are the Pliocene-Miocene, Upper Floridan, Lisbon, Nanafalia-Clayton, and Providence-Ripley. The largest pumping centers in the area are Andalusia and Monroeville, where groundwater use is about 5 and 4 million gal/day, respectively. Estimated maximum withdrawal in 1987 for all uses in the area was about 44 million gal/day. Depressions have developed in the potentiometric surfaces of the Lisbon aquifer near Andalusia and Opp, the Nanafalia-Clayton aquifer near Luverne, Andalusia, Beatrice, and Monroeville, and the Providence-Ripley aquifer at Greenville. Significant declines in the potentiometric surfaces of the other major aquifers are not apparent. Recharge areas for all major aquifers are susceptible to contamination, but the probability of contamination of the Lisbon, Nanafalia-Clayton, and Providence-Ripley aquifers is low because the recharge areas are remote from areas of the withdrawal. The depressions in the recharge area for the Upper Floridan aquifer and the area where the Pliocene-Miocene aquifer is overlain by the gravelly sands of the Citronelle Formation are highly susceptible to contamination from the surface. (USGS)

  11. Contaminants of emerging concern in surface waters in Barbados, West Indies.

    Science.gov (United States)

    Edwards, Quincy A; Kulikov, Sergei M; Garner-O'Neale, Leah D; Metcalfe, Chris D; Sultana, Tamanna

    2017-11-14

    Contaminants of emerging concern (CECs), including pharmaceuticals, artificial sweeteners, steroid hormones, and current-use pesticides have been detected in surface waters around the world, but to date, there have been no reports in the peer-reviewed literature on the levels of these classes of contaminants in freshwater resources in the Caribbean region. In the present study, multi-residue solid phase extraction (SPE) and liquid chromatography with tandem mass spectroscopy (LC-MS/MS) were used to analyze grab samples of surface waters collected from five different watersheds in Barbados, West Indies. The artificial sweeteners (AS), acesulfame, cyclamate, saccharin, and sucralose were widely detected in the watersheds, indicating contamination from domestic wastewater, and the concentrations of these chemical tracers in water were correlated with the concentrations of the non-prescription pharmaceutical, ibuprofen (R 2 values of 0.4-0.6). Surprisingly, the concentrations of another chemical tracer of domestic wastewater, caffeine were not correlated with ibuprofen or AS concentrations. Several other prescription pharmaceuticals and the steroid hormones, estrone and androstenedione, were detected in selected watersheds at low ng/L concentrations. The fungicide, chlorothalonil was widely detected in surface waters at low (contamination of water resources by pharmaceuticals.

  12. Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects.

    Science.gov (United States)

    Mohamed, Seif; Polyzois, Ioannis; Renvert, Stefan; Claffey, Noel

    2010-05-01

    This study was designed to evaluate the effect of surface contamination on osseointegration of dental implants surrounded by a circumferential bone defect and to compare osseointegration around Osseotite with that around Nanotite implants. The premolars on both sides of the mandible in four beagle dogs were extracted. Following 4 months healing, two Nanotite implants and two Osseotite implants were partially inserted in the left side of each mandible. Some threads protruded from the tissues into the oral cavity. Following a 5 week healing period, the implants were removed and the contaminated part of each implant was cleaned. They were then installed to the full implant length on the contra lateral side of the mandibles. The coronal 5 mm of each implant was surrounded by 1 mm circumferential bone defect. Following 12 weeks of healing period, the dogs were sacrificed and biopsies were obtained. Ground sections were prepared for histomorphometric analysis. All implants were associated with direct bone-to-implant contact on the portion of the implant surface contaminated previously and surrounded by bone defect. Nanotite implants performed better than Osseotite implants. The results demonstrated that implant surfaces, which were contaminated previously and were surrounded by bone defects, can osseointegrate.

  13. A decision-making process on cleanup of contaminated surface soil

    International Nuclear Information System (INIS)

    Yasuda, Hiroshi

    1996-01-01

    This study presents principles for determining derived intervention levels (DILs) for surface soil cleanup. The people concerned were divided into major three groups: residents, responsible parties, and cleanup workers; it was considered that each group has different interests. The DILs for soil cleanup were determined from the viewpoints of these three groups: safety of residence, advantages of the countermeasures, and safety of cleanup activities, respectively. An example process for determination of the DILs in accordance with the principles was also presented for a site contaminated by 137 Cs. This decision-making frame is expected to be applicable to other contaminants. (author)

  14. Estimation of contamination on plant surfaces due to deposition of radionuclides from the atmosphere

    International Nuclear Information System (INIS)

    Simmonds, J.R.

    1983-01-01

    Calculations of Normalized Specific Activity (NSA), the ratio of concentration of a contaminant per unit of vegetation to its daily rate of deposition onto the ground, have been used as a basis for determining interception factors and retention half-lives for radioactivity deposited on grain and leafy vegetables. The resulting interception factors and retention half-lives are for use in assessing contamination levels on crops at harvest during conditions of continuous deposition. The results of the study indicate that the behaviour of strontium and caesium on plant surfaces is fairly similar but that plutonium behaves in a notably different way. (author)

  15. Heavy metal contamination in surface runoff sediments of the urban area of Vilnius, Lithuania

    Directory of Open Access Journals (Sweden)

    Gytautas Ignatavičius

    2017-02-01

    Full Text Available Surface runoff from urbanized territories carries a wide range of pollutants. Sediments in untreated runoff from direct discharge stormwater systems significantly contribute to urban waterway pollution. In this study, heavy metal (Pb, Zn, Cu, Cr, Ba, As and Fe contamination in surface runoff sediments of the urban area of the city of Vilnius was investigated. The surface runoff sediment samples were collected from seven dischargers with the highest volume rate of water flow and concentrations of suspended solids. The geospatial analysis of the distribution of heavy metals shows that there are several active pollution sources supplying the dischargers with contaminated sediments. Most of these areas are located in the central part of the city and in old town with intense traffic. Principal components analysis and t-test results clearly depicted the significantly different chemical compositions of winter and autumn surface sediment samples. The sampling approach and assessment of results provide a useful tool to examine the contamination that is generated in urban areas, distinguish pollution sources and give a better understanding of the importance of permeable surfaces and green areas.

  16. Contribution to Surface Water Contamination Understanding by Pesticides and Pharmaceuticals, at a Watershed Scale

    Directory of Open Access Journals (Sweden)

    Stéphanie Piel

    2012-12-01

    Full Text Available This study aims at understanding the presence of regulated and emerging micropollutants, particularly pesticides and pharmaceuticals, in surface water, regarding spatial and temporal influences at a watershed scale. The study of relations between micropollutants and other water quality and hydroclimatic parameters was carried out from a statistical analysis on historical and experimental data of different sampling sites from the main watershed of Brittany, western France. The outcomes point out the influence of urban and rural areas of the watershed as well as the impact of seasons on contamination variations. This work contributes to health risk assessment related to surface water contamination by micropollutants. This approach is particularly interesting in the case of agricultural watersheds such as the one studied, where more than 80% of surface water is used to produce drinking water.

  17. Removal and treatment of radioactive, organochlorine and heavy metal contaminants from solid surfaces

    International Nuclear Information System (INIS)

    Grieco, S.A.; Neubauer, E.D.; Rhea, J.R.; Escue, L.S.

    1996-01-01

    The U.S. Department of Energy (DOE) is defining decontamination and decommissioning (D ampersand D) obligations at its sites. Current D ampersand D activities are Generally labor intensive, use chemical reagents that are difficult to treat, and may expose workers to radioactive and hazardous chemicals. Therefore, new technologies are desired that minimize waste, allow much of the decommissioned materials to be reused rather than disposed of as waste, and produce wastes that will meet disposal criteria The O'Brien ampersand Gere Companies tested a scouring decontamination system on concrete and steel surfaces contaminated with radioactive and hazardous wastes under the sponsorship of Martin Marietta Energy Systems, Inc. (MMES) at DOE's K-25 former gaseous diffusion plant in Oak Ridge, Tennessee. The scouring system that O'Brien ampersand Gere Companies developed removes fixed radioactive and hazardous surface contamination, while leaving the surface intact. Blasting residuals are dissolved and treated using physical/chemical processes. Bench- and pilot-scale testing of the soda blasting system was conducted between December 1993 and September 1994 on surfaces contaminated with uranium, technetium, heavy metals, and PCBs. Areas of concrete and metal surfaces were blasted. Blasting residuals were dissolved in tap water and treated for radioactive, hazardous, and organochlorine constituents. The treatment system comprised pH adjustment, aeration, solids settling, filtration, carbon adsorption, and ion exchange. This system produced treated water and residual solid waste. Testing demonstrated that the system is capable of removing greater than 95% of radioactive and PCB surface contamination to below DOE's unrestricted use release limits; aqueous radionuclides, heavy metals, and PCBs were below DOE and USEPA treatment objectives after blasting residuals treatment. Waste residuals volume was decreased by 71%

  18. The effect of surface-active solutes on water flow and contaminant transport in variably saturated porous media with capillary fringe effects.

    Science.gov (United States)

    Henry, E J; Smith, J E

    2002-06-01

    storage capacity of the vadose zone, the dye breakthrough time to the water table was more than twice as fast when the contaminant solution contained surfactant. The extensive propagation of the drying front and the effect of vadose zone drainage on contaminant breakthrough time suggest the importance of considering surface tension effects on unsaturated flow and transport in systems containing surface-active organic contaminants or systems, where surfactants are used for remediation of the vadose zone or unconfined aquifers.

  19. H51E-1535: Biogeochemical factors influencing the transport and fate of colloids and colloid-associated contaminants in the vadose zone

    Science.gov (United States)

    The vadose zone exhibits large spatial and temporal variability in many physical, chemical, and biological factors that strongly influence the transport and fate of colloids (e.g., microbes, nanoparticles, clays, and dissolved organic matter) and colloid-associated contaminants (e.g., heavy metals, ...

  20. Bioremediation of soils contaminated by hydrocarbons at the coastal zone of “Punta Majagua”.

    Directory of Open Access Journals (Sweden)

    Jelvys Bermúdez Acosta

    2012-03-01

    Full Text Available The purpose of this research was to describe and assess the main results in the process of bioremediation of 479 m3 of petroleum residuals spilled on the soil and restrained into four deposits of fuel on the coastal zone of “Punta Majagua”, Cienfuegos. The volume of hydrocarbons spilled and contained into the tanks was determined by means of their previous mixture with fertile ground in a ratio of 3/1. The hydrocarbons were disposed in a bioremediation area of 115 m X 75m built in situ. In turn 54, 5 m3 of BIOIL - FC were applied, which were fermented in an industrial bioreactor of 12000 L. An initial sampling was carried out registering values of total hydrocarbons (HTP higher than 41880 mg/kg, with high concentrations of Saturated hydrocarbons, aromatics, resins, asphaltens (SARA. Three subsequent samples were taken with a sampling interval of 0, 45, 90 and 120 days of the application. An average concentration of 1884.57 mg/kg of total hydrocarbons was obtained at 120 days with an average removal rate of 94.8%, moreover values of 94.6%, 90.78%, 86.99% y 79.9% of SARA were respectively reported.

  1. Overflow and microbiological contamination in surface and groundwaters in La Costa city (Canelones department, Uruguay)

    International Nuclear Information System (INIS)

    Marmisolle, J.; Goso Aguilar, C.

    2006-01-01

    In this paper the results of a geological risk study made during 2005 related to overflow and microbiological water contamination at Ciudad de la Costa City (Canelones department) are shown. This city has been showed a great urban growth for the last three decades. New hydrogeological studies looking forward the phreatic level and its bacteriological quality allow to know the level of the risk along 2005´s first semester. The top of the phreatic table in 40% of the studied area is below than 0.50 meter depth. The results of fourteen bacteriologic analyses in groundwater samples show extreme contamination values in faecal colliform, Pseudomona sp. and Aeruginosa content. Both surface drainage and beach water bacteriologic analyses did not show contamination values except those corresponding to Carrasco creek

  2. A review and outlook for the removal of radon-generated Po-210 surface contamination

    Science.gov (United States)

    Guiseppe, V. E.; Christofferson, C. D.; Hair, K. R.; Adams, F. M.

    2018-01-01

    The next generation low-background detectors operating deep underground aim for unprecedented low levels of radioactive backgrounds. The deposition and presence of radon progeny on detector surfaces is an added source of energetic background events. In addition to limiting the detector material's radon exposure in order to reduce potential surface backgrounds, it is just as important to clean surfaces to remove inevitable contamination. Such studies of radon progeny removal have generally found that a form of etching is effective at removing some of the progeny (Bi and Pb), however more aggressive techniques, including electropolishing, have been shown to effectively remove the Po atoms. In the absence of an aggressive etch, a significant fraction of the Po atoms are believed to either remain behind within the surface or redeposit from the etching solution back onto the surface. We explore the chemical nature of the aqueous Po ions and the effect of the oxidation state of Po to maximize the Po ions remaining in the etching solution of contaminated Cu surfaces. We present a review of the previous studies of surface radon progeny removal and our findings on the role of oxidizing agents and a cell potential in the preparation of a clean etching technique.

  3. Skin and surface lead contamination, hygiene programs, and work practices of bridge surface preparation and painting contractors.

    Science.gov (United States)

    Virji, M Abbas; Woskie, Susan R; Pepper, Lewis D

    2009-02-01

    A 2005 regulatory review of the lead in construction standard by the Occupational Safety and Health Administration (OSHA) noted that alternative pathways of exposure can be as significant as inhalation exposure and that noncompliance with the standard pertaining to hygiene facilities and practices was the second most commonly violated section of the standard. Noncompliance with provisions of the standard and unhealthy work and hygiene practices likely increase the likelihood of take-home lead via contaminated clothing, automobiles, and skin, thus contributing to elevated blood lead levels (BLL) among construction workers and their family members. We performed a cross-sectional study of bridge painters working for small contractors in Massachusetts to investigate causes of persistent elevated BLLs and to assess lead exposures. Thirteen work sites were evaluated for a 2-week period during which surface and skin wipe samples were collected and qualitative information was obtained on personal hygiene practices, decontamination and hand wash facilities, and respiratory protection programs. Results showed lead contamination on workers' skin, respirators, personal automobiles, and the decontamination unit, indicating a significant potential for take-home lead exposure. Overall, the geometric mean (GM) skin lead levels ranged from 373 microg on workers' faces at end of shift to 814 microg on hands at break time. The overall GM lead level inside respirators was 143 microg before work and 286 microg after work. Lead contamination was also present inside workers' personal vehicles as well as on surfaces inside the clean side of the decontamination unit. Review of the respiratory protection programs, work site decontamination and hand wash facilities, and personal hygiene practices indicated that these factors had significant impact on skin and surface contamination levels and identified significant opportunities for improving work site facilities and personal practices

  4. Tourmaline, an indicator of external Mg-contamination of granitic pegmatites from host serpentinite; examples from the Moldanubian Zone, Czech Republic

    Science.gov (United States)

    Novák, M.; Prokop, J.; Losos, Z.; Macek, I.

    2017-09-01

    Dominant primary solidus and minor subsolidus tourmalines from a variety of granitic pegmatites enclosed in serpentinites of the Moldanubian Zone, Czech Republic were examined, mainly by electron probe micro-analyser, to reveal the degree of external Mg(Ca)-contamination from their host rocks. The rocks include: (i) homogeneous to slightly heterogeneous nests of plagioclase-tourmaline rocks (group A) of anatectic or metasomatic origin, (ii) subhomogeneous to simply zoned barren pegmatite dikes (group B), and (iii) Li-bearing zoned pegmatite dikes of rare-element class (group C). The plagioclase-tourmaline rocks (group A) show spatial relation to pegmatites of the group B. Mostly black primary tourmalines (dravite, oxy-dravite, uvite, schorl, oxy-schorl, fluor-schorl) show extensive Mg- and Ca-contamination (group A), moderate Mg- and locally minor Ca-contamination (group B plus the locality Věžná I of the group C) and weak Mg-contamination of the tourmaline solely from outermost pegmatite units (group C); tourmalines from internal units of the pegmatites are typically Mg-free. The substitution mechanisms include MgR2+ -1 (R2+ = Fe2+ > Mn2+) in all groups, NaR2+ (□Al)-1 and R2+ (OH) (AlO)-1 in Ca-poor tourmalines and CaO (NaOH)-1 combined with the substitution CaR2+ (NaAl)-1 in Ca-enriched tourmalines (group A). Both Mg- and Ca-contamination events were very likely contemporaneous. The extent of contamination is higher in small and texturally simple plagioclase-tourmaline rocks (group A). Larger and more highly evolved Li-bearing pegmatites (group C) with zoned internal structure show a high degree of undercooling; consequently, rapid crystallization of outer zones with biotite and/or tourmaline depleted melt in almost all Mg and isolated the pegmatite body from further external contamination during solidus crystallisation. The granitic pegmatites (group B and group C) were open to the host serpentinite during early solidus crystallization immediately after

  5. Surface contamination of the LIL optical components and their evolution after laser irradiation (3. series of experiments)

    International Nuclear Information System (INIS)

    Palmier, St.; Garcia, S.; Lamaignere, L.; Rullier, J.L.; Tovena, I.

    2007-01-01

    In the context of the Laser Mega-Joule (LMJ) project, the third series of experiments achieved the particle contamination characterization found in the Laser Integration Line (LIL) environment. This study is focused on 2 zones: the frequency conversion crystals and beam focusing area and the amplification zone. In each zone, the particles have the same chemical nature. The irradiation of samples contaminated in these zones does not create any critical damage, as already observed in the first and second series of experiments. In this third series of experiments, an interesting phenomenon is quantified: the cleaning laser effect. In the best configuration studied (particles in the backward, fluence of 10 J/cm 2 , 355 nm wavelength and 2.5 ns), 95% of the particles larger than 3 μm are eliminated after one single irradiation. (authors)

  6. Description of Rhodanobacter denitrificans sp. nov., isolated from nitrate-rich zones of a contaminated aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Om [Florida State University; Green, Stefan [Florida State University; Jasrotia, Puja [Florida State University; Overholt, Will [Florida State University; Canion, Andy [Florida State University; Watson, David B [ORNL; Brooks, Scott C [ORNL; Kostka, Joel [Florida State University

    2011-01-01

    Bacterial strains 2APBS1T and 116-2 were isolated from the subsurface of a nuclear legacy waste site where sediments are co-contaminated with large amounts of acidity, nitrate, metal radionuclides and other heavy metals. A combination of physiological and genetic assays indicated that these strains represent the first members of the Rhodanobacter genus shown to be capable of complete denitrification. Cells of strain 2APBS1T and 116-2 were Gram negative, non-spore-forming, rods, 3-5 micro;m long and 0.25-0.5 m in diameter. The isolates were facultative anaerobes, and had temperature and pH optima for growth at 30 C and pH 6.5, respectively, and could tolerate up to 2.0 % NaCl, though growth improved in its absence. Strains 2APBS1T and 116-2 contained fatty acid profiles and 100 % Q-8 ubiquinone, that are characteristic features of the genus Rhodanobacter. Although strains 2APBS1T and 116-2 share high SSU rRNA gene sequence similarity to R. thiooxydans (>99%), DNA-DNA hybridization values were substantially below the 70% threshold used to designate novel species. Thus, based on genotypic, phylogenetic, chemotaxonomic and physiological differences, strains 2APBS1T and 116-2 are considered to represent a novel species of the genus Rhodanobacter, for which the name Rhodanobacter denitrificans sp. nov is proposed. The type strain is 2APBS1T (=DSM 23569T =JCM 17641T). Strain 116-2 (=DSM 24678 = JCM 17642) is a reference strain.

  7. Description of Rhodanobacter denitrificans sp. nov., isolated from nitrate-rich zones of a contaminated aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Om [Florida State University, Tallahassee; Green, Stefan [Florida State University, Tallahassee; Jasrotia, Puja [Florida State University, Tallahassee; Overholt, Will [Florida State University, Tallahassee; Canion, Andy [Florida State University, Tallahassee; Watson, David B [ORNL; Brooks, Scott C [ORNL; Kostka, [Georgia Institute of Technology, Atlanta

    2012-01-01

    Bacterial strains 2APBS1T and 116-2 were isolated from the subsurface of a nuclear legacy waste site where sediments are co-contaminated with large amounts of acidity, nitrate, metal radionuclides and other heavy metals. A combination of physiological and genetic assays indicated that these strains represent the first members of the Rhodanobacter genus shown to be capable of complete denitrification. Cells of strain 2APBS1T and 116-2 were Gram negative, non-spore-forming, rods, 3-5 micro;m long and 0.25-0.5 m in diameter. The isolates were facultative anaerobes, and had temperature and pH optima for growth at 30 C and pH 6.5, respectively, and could tolerate up to 2.0 % NaCl, though growth improved in its absence. Strains 2APBS1T and 116-2 contained fatty acid profiles and 100 % Q-8 ubiquinone, that are characteristic features of the genus Rhodanobacter. Although strains 2APBS1T and 116-2 share high SSU rRNA gene sequence similarity to R. thiooxydans (>99%), DNA-DNA hybridization values were substantially below the 70% threshold used to designate novel species. Thus, based on genotypic, phylogenetic, chemotaxonomic and physiological differences, strains 2APBS1T and 116-2 are considered to represent a novel species of the genus Rhodanobacter, for which the name Rhodanobacter denitrificans sp. nov is proposed. The type strain is 2APBS1T (=DSM 23569T =JCM 17641T). Strain 116-2 (=DSM 24678 = JCM 17642) is a reference strain.

  8. Emerging contaminants in surface waters in China—a short review

    International Nuclear Information System (INIS)

    Yang, Guang; Zhang, Guangming; Fan, Maohong

    2014-01-01

    Emerging contaminants (ECs) have drawn attention to many countries due to their persistent input and potential threat to human health and the environment. This article reviews the current contamination sources and their status for surface waters in China. The contamination levels of ECs in surface waters are in the range ng L −1 to μg L −1 in China, apparently about the same as the situation in other countries. ECs enter surface water via runoff, drainage, rainfall, and wastewater treatment effluent. The frequency of occurrence of ECs increased rapidly from 2006 to 2011; a significant reason is the production and consumption of pharmaceuticals and personal care products. As for the distribution of EC pollution in China, the frequency of occurrence of ECs in eastern regions is higher than in western regions. A majority of EC studies have focused on surface waters of the Haihe River and Pearl River watersheds due to their highly developed industries and intense human activity. Legislative and administrative regulation of ECs is lacking in China. To remove ECs, a number of technologies, such as absorption by activated carbon, membrane filtration technology, and advanced oxidation processes, have been researched. (letter)

  9. Microbiological quality control of single-walled carbon-nanotubes-coated surfaces experimentally contaminated

    International Nuclear Information System (INIS)

    Natalizi, T.; Frioni, A.; Passeri, D.; Pantanella, F.

    2013-01-01

    The emergence of new nanotechnologies involves the spreading of nanoparticles in various fields of human life. Nanoparticles in general and, more specifically, carbon nanotubes have been adopted for many practical approaches i.e.: coatings for medical devices, food process industry and drug delivery. Humans will be increasingly exposed to nanoparticles but the susceptibility of nanostructured materials to microbial colonization in process of manufacturing and storage has not been thoroughly considered. Therefore, the microbiological quality control of nanoparticles plays a pivotal role. Different analytical methods have been attempted for detecting bacterial population contaminating a surface, but no one can be considered fully appropriate. Here, BioTimer Assay (BTA) and conventional sonication followed by colony forming units method (S-CFU) were applied for microbiological quality control of single-walled carbon nanotubes (SWCNTs)-coated surfaces experimentally contaminated with Streptococcus mutans and Pseudomonas aeruginosa. Our results demonstrated that S-CFU is unreliable to actually determine the number of bacteria, contaminating abiotic surfaces, as it does not detach all adherent bacteria and kills part of the bacterial population. Instead, BTA is a reliable method to enumerate bacteria colonizing SWCNTs-coated surfaces and can be considered a useful tool for microbiological quality control of nanomaterials for human use.

  10. Emerging contaminants in surface waters in China—a short review

    Science.gov (United States)

    Yang, Guang; Fan, Maohong; Zhang, Guangming

    2014-07-01

    Emerging contaminants (ECs) have drawn attention to many countries due to their persistent input and potential threat to human health and the environment. This article reviews the current contamination sources and their status for surface waters in China. The contamination levels of ECs in surface waters are in the range ng L-1 to μg L-1 in China, apparently about the same as the situation in other countries. ECs enter surface water via runoff, drainage, rainfall, and wastewater treatment effluent. The frequency of occurrence of ECs increased rapidly from 2006 to 2011; a significant reason is the production and consumption of pharmaceuticals and personal care products. As for the distribution of EC pollution in China, the frequency of occurrence of ECs in eastern regions is higher than in western regions. A majority of EC studies have focused on surface waters of the Haihe River and Pearl River watersheds due to their highly developed industries and intense human activity. Legislative and administrative regulation of ECs is lacking in China. To remove ECs, a number of technologies, such as absorption by activated carbon, membrane filtration technology, and advanced oxidation processes, have been researched.

  11. Characterizing multiple sources and interaction in the critical zone through Sr-isotope tracing of surface and groundwater

    Science.gov (United States)

    Negrel, Philippe; Pauwels, Hélène

    2017-04-01

    The Critical Zone (CZ) is the lithosphere-atmosphere boundary where complex physical, chemical and biological processes occurs and control the transfer and storage of water and chemical elements. This is the place where life-sustaining resources are, where nutrients are being released from the rocks. Because it is the place where we are living, this is a fragile zone, a critical zone as a perturbed natural ecosystem. Water resources in hard-rocks commonly involve different hydrogeological compartments such as overlying sediments, weathered rock, the weathered-fissured zone, and fractured bedrock. Streams, lakes and wetlands that drain such environments can drain groundwater, recharge groundwater, or do both. Groundwater resources in many countries are increasingly threatened by growing demand, wasteful use, and contamination. Surface water and shallow groundwater are particularly vulnerable to pollution, while deeper resources are more protected from contamination. Here, we first report on Sr isotope data as well as major ions, from shallow and deep groundwater in several granite and schist areas over France with intensive agriculture covering large parts of these catchments. In three granite and Brioverian 'schist' areas of the Armorican Massif, the range in Sr contents in groundwater from different catchments agrees with previous work on groundwater sampled from granites in France. The Sr content is well correlated with Mg and both are partly related to agricultural practices and water rock interaction. The relationship between Sr- isotope and Mg/Sr ratios allow defining the different end-members, mainly rain, agricultural practice and water-rock interaction. The data from the Armorican Massif and other surface and groundwater for catchment draining silicate bedrocks (300-450Ma) like the Hérault, Seine, Moselle, Garonne, Morvan, Margeride, Cantal, Pyrénées and Vosges are scattered between at least three geochemical signatures. These include fertilizer and

  12. Occurrence of perchloroethylene in surface water and fish in a river ecosystem affected by groundwater contamination.

    Science.gov (United States)

    Wittlingerová, Zdena; Macháčková, Jiřina; Petruželková, Anna; Zimová, Magdalena

    2016-03-01

    Long-term monitoring of the content of perchloroethylene (PCE) in a river ecosystem affected by groundwater contamination was performed at a site in the Czech Republic. The quality of surface water was monitored quarterly between 1994 and 2013, and fish were collected from the affected ecosystem to analyse the content of PCE in their tissue in 1998, 2011 and 2012. Concentrations of PCE (9-140 μg/kg) in the tissue of fish collected from the contaminated part of the river were elevated compared to the part of the river unaffected by the contamination (ND to 5 μg/kg PCE). The quality of surface water has improved as a result of groundwater remediation during the evaluated period. Before the remedial action, PCE concentrations ranged from 30 to 95 μg/L (1994-1997). Following commencement of remedial activities in September 1997, a decrease in the content of PCE in the surface water to 7.3 μg/L (1998) and further to 1 μg/L (2011) and 1.1 μg/L (2012) led to a progressive decrease in the average concentration of PCE in the fish muscle tissue from 79 μg/kg (1998) to 24 (2011) and 30 μg/kg (2012), respectively. It was determined that the bioconcentration of PCE does not have a linear dependence because the decrease in contamination in the fish muscle tissue is not directly proportional to the decrease in contamination in the river water. The observed average bioconcentration factors were 24 and 28 for the lower concentrations of PCE and 11 for the higher concentrations of PCE in the river. In terms of age, length and weight of the collected fish, weight had the greatest significance for bioconcentration, followed by the length, with age being evaluated as a less significant factor.

  13. Filtration of contaminated suspended solids for the treatment of surface water.

    Science.gov (United States)

    Mulligan, Catherine N; Davarpanah, Neginmalak; Fukue, Masaharu; Inoue, Tomohiro

    2009-02-01

    As few technologies exist worldwide for the treatment of contaminated surface water, a new approach is currently under development consisting of an in situ water treatment system based on a floating filtration process for adsorbed contaminants such as heavy metals. Laboratory filtration tests were performed for the removal of contaminated suspended solids (SS) from surface water. SS, chemical oxygen demand (COD), and organic carbon (OC) were monitored. Of the four filters (two non-woven geotextiles, a woven geotextile and a sand filter) evaluated, filter 1 (a non-woven geotextile) was the most effective for removal % of the total suspended solids. The results demonstrated excellent efficiency by filter No. 1, for reducing turbidity by 93-98%, as well as SS by up to 98.9% and COD by 65-71% for three sites with initial turbidities of 70, 20, and 120 NTU, respectively. The level of heavy metal removal was 98.9% due the heavy metal content of the suspended solids (60 mg kg(-1) of Cu, 90 mg kg (-1) of Ni, 130 mg kg(-1) of Zn, 200 mg kg(-1) of Cr, and 80 mg kg(-1) of Pb). The development of this technology could potentially protect the public and aquatic plants and animals from dangerous contaminants such as heavy metals adsorbed onto the suspended solids.

  14. The dynamic response of hyporheic zone redox zonation after surface flow perturbation

    Science.gov (United States)

    Kaufman, M.; Zheng, L.; Cardenas, M. B.

    2015-12-01

    As water in a stream or river flows over ripples and other bedforms, differential surface pressures create bedform-induced hyporheic exchange. The oxygen, carbon, and nutrients carried into the bed by the surface water as well as those already existing in the bed material form the basis for microbial communities in the sediment.The resulting dissolved oxygen conditions are a critical control on the ecological function of the hyporheic zone (HZ), from both micro- and macro-biological habitat perspectives. Because hyporheic exchange rates are controlled by surface flow velocity, variations in surface flow have significant impact on the subsurface oxygen conditions. Most rivers are subject to flow velocity variations due to natural forcing including precipitation and variations in evapotranspiration as well as anthropogenic forces like dam releases. We use a large (10m x 0.7m x 0.3m) programmable flume instrumented with a bedform-scale high-resolution planar optode dissolved oxygen imaging system to observe the distribution of oxygenated sediment within the HZ over time. Using this system we characterize the rate at which hyporheic oxygen conditions reconfigure in response to changes in the surface flow velocity, particularly the time it takes for conditions to recover after a pulse of increased flow velocity. In addition, we make use of numerical models to further identify critical response time drivers. With these tools, we develop equations to describe the post-disturbance recovery time as a function of relative pulse magnitude and duration. Using these equations we can predict the time scale over which the hyporheic zone will recover following both natural and anthropogenic flow regime disturbances. Being able to predict the magnitude and duration of dissolved oxygen changes in the wake of flow perturbing events allows us to better understand the impact these disturbances have on the ecology of the hyporheic zone.

  15. Incisor inclination determined by the light reflection zone on the tooth's surface.

    Science.gov (United States)

    Brezniak, Naphtali; Turgeman, Ronit; Redlich, Meir

    2010-01-01

    Maxillary incisors are the most prominent teeth, and their inclination plays an important role in esthetics. In orthodontics, the inclination of central incisors is usually determined by cephalometric analysis. This publication suggests an adjunctive clinical measure to determine this inclination. The objective of the study was to examine the correlation between the inclinations of maxillary incisors measured on a cephalometric lateral headfilm and the light reflection zone appearing on the buccal surface of the teeth on anterior intraoral photographs. Maxillary incisor inclination, divided into three levels-proclination, normal inclination, and retroclination-of 65 patients was determined by means of cephalometric analysis, using three angular measurements (maxillary incisor to sella-nasion, maxillary incisor to Frankfort horizontal, and maxillary incisor to nasion-point A). The anterior intraoral photographs of the 65 patients were divided into 3 groups according to the reflection zone on the maxillary central incisors as determined from the photographs: incisal, middle, and gingival. The correlation and agreement between the two parameters were evaluated by chi-square and kappa statistics. The light reflection zone on the tooth surface as it appears on intraoral photographs-incisal, middle, or gingival-correlated with statistical significance to the angular inclination of the teeth-proclination, normal inclination, and retroclination, respectively-as determined by means of cephalometric analysis (P light reflection zone viewed on the buccal surface of intraoral photographs. This method might be used as a new screening tool and further as an additional clinical tool for assessing treatment plans in orthodontics and other fields of dentistry.

  16. Field emission and high voltage cleaning of particulate contaminants on extended metallic surfaces

    International Nuclear Information System (INIS)

    Tan, J.; Bonin, B.; Safa, H.

    1996-01-01

    The vacuum insulation properties of extended metallic surfaces depends strongly on their cleanliness. The usual technique to reduce electronic field emission from such surfaces consists in exposing them to very high electric fields during limited periods of time. This kind of processing also reduces the occurrence of vacuum breakdown. The processing of the surface is generally believed to be due to a thermomechanical destruction of the emitting sites, initiated by the emission itself. Comparison of the electric forces vs adherence forces which act on dust particles lying on the surface shows that the processing could also be due simply to the mechanical removal of the dust particles, with a subsequent reduction of field emission from the contaminated surface. (author)

  17. Assessment of Aflatoxin Contamination of Maize, Peanut Meal and Poultry Feed Mixtures from Different Agroecological Zones in Cameroon

    Directory of Open Access Journals (Sweden)

    Jean Raphaël Kana

    2013-04-01

    Full Text Available Mycotoxins affect poultry production by being present in the feed and directly causing a negative impact on bird performance. Carry-over rates of mycotoxins in animal products are, in general, small (except for aflatoxins in milk and eggs therefore representing a small source of mycotoxins for humans. Mycotoxins present directly in human food represent a much higher risk. The contamination of poultry feed by aflatoxins was determined as a first assessment of this risk in Cameroon. A total of 201 samples of maize, peanut meal, broiler and layer feeds were collected directly at poultry farms, poultry production sites and poultry feed dealers in three agroecological zones (AEZs of Cameroon and analyzed for moisture content and aflatoxin levels. The results indicate that the mean of the moisture content of maize (14.1% was significantly (P < 0.05 higher than all other commodities (10.0%–12.7%. Approximately 9% of maize samples were positive for aflatoxin, with concentrations overall ranging from <2 to 42 µg/kg. Most of the samples of peanut meal (100%, broiler (93.3% and layer feeds (83.0% were positive with concentrations of positive samples ranging from 39 to 950 µg/kg for peanut meal, 2 to 52 µg/kg for broiler feed and 2 to 23 µg/kg for layer feed. The aflatoxin content of layer feed did not vary by AEZ, while the highest (16.8 µg/kg and the lowest (8.2 µg/kg aflatoxin content of broiler feed were respectively recorded in Western High Plateau and in Rainforest agroecological zones. These results suggest that peanut meal is likely to be a high risk feed, and further investigation is needed to guide promotion of safe feeds for poultry in Cameroon.

  18. A state of the art on the measurement of the radioactive contamination in the inner surface of the pipe

    Energy Technology Data Exchange (ETDEWEB)

    Seo, B. K.; Lee, K. W.; Oh, W. Z.; Woo, Z. H.; Kim, G. H

    2004-11-15

    Many radioactive wastes are produced during the decommissioning of the nuclear facilities. Their radiological characterization must be estimated for disposal and reuse. Especially, it is very difficult to measure the in-pipe surface contamination, because of the difficulty of access. So, it is necessary to develop the measurement technology for the in-pipe surface contamination. In the developed counties of the decommissioning technology such as America, Japan etc. they developed the measuring device for the in-pipe radioactive contamination and performed the capacity estimation. In this report, the state of the art on the measurement of the radioactive contamination in the inner surface of the pipe and radiation detector for measuring the each radiation(alpha, beta, and gamma) proceeding around the world was analyzed. By means of such technology analysis, we will develop the measuring technology of the radioactive contamination in the inner surface of the pipe and apply to the decommissioning sites.

  19. New miniaturized alpha/beta spectrometric system for the surface contamination monitoring and radon personal dosimeter

    International Nuclear Information System (INIS)

    Streil, T.; Oeser, V.; Holfeld, G.

    1998-01-01

    The heart of the new miniaturized alpha/beta spectroscopic system is a Smart Card MCA having a 12 bit resolution and a 32 bit memory for each channel with the size of a cheque card. The system consists of a single or up to 12 alpha spectrometers in a battery powered casing with connectors for direct detector/amplifier module plugging. Surface contamination in the order of 1 Bq/cm 2 of 239 Pu can be measured. (M.D.)

  20. Evaluation of surface contamination based on certifiably traceable, internationally accreditable measurements

    International Nuclear Information System (INIS)

    Whitlock, G.D.

    1992-01-01

    National Accreditation and Measurement Service (NAMAS) adopted by the EUROMET agreement requires that the calibration of monitoring instruments be traceable internationally with the objective that radiation hazard assessment be improved. This objective is achieved for Tritium surface contamination by employing calibration sources and evaluation methods which comply with ISO standards including the measurement of activity removable by Volatilization as well as dust. Consideration should be given to organic binding of tritium in the skin with its implications in the event of litigation. (author)

  1. Detecting buried radium contamination using soil-gas and surface-flux radon meaurements

    International Nuclear Information System (INIS)

    Karp, K.E.

    1988-06-01

    The Technical Measurements Center (TMC) has investigated the effectiveness of using radon soil-gas under surface-flux measurments to locate radium contamination that is buried sufficiently deep to be undetectable by surface gamma methods. At the first test site studied, an indication of a buried source was revealed by mapping anomalous surface-flux and soil-gas concentrations in the near surface overburden. The mapped radon anomalies were found to correspond in rough outline to the shape of the areal extent of the deposit as determined by borehole gamma-ray logs. The 5.9pCi/g radium deposit, buried 2 feet below the surface, went undetected by conventional surface gamma measurements. Similar results were obtained at the second test site where radon and conventional surface gamma measurements were taken in an area having radium concentrations ranging from 13.3 to 341.0 pCi/g at a depth of 4 feet below the surface. The radon methods were found to have a detection limit for buried radium lower than that of the surface gamma methods, as evidenced by the discovery of the 13.3 pCi/g deposit which went undetected by the surface gamma methods. 15 refs., 33 figs., 8 tabs

  2. Acid-base status of soils in groundwater discharge zones — relation to surface water acidification

    Science.gov (United States)

    Norrström, Ann Catrine

    1995-08-01

    Critical load calculations have suggested that groundwater at depth of 2 m in Sweden is very sensitive to acid load. As environmental isotope studies have shown that most of the runoff in streams has passed through the soil, there is a risk in the near future of accelerated acidification of surface waters. To assess the importance of the last soil horizon of contact before discharge, the upper 0-0.2m of soils in seven discharge zones were analysed for pools of base cations, acidity and base saturation. The sites were about 3-4 m 2 in size and selected from two catchments exposed to different levels of acid deposition. The soils in the seven sites had high concentrations of exchangeable base cations and consequently high base saturation. The high correlation ( r2 = 0.74) between base saturation in the soils of the discharge zones and mean pH of the runoff waters suggested that the discharge zone is important for surface water acidification. The high pool of exchangeable base cations will buffer initially against the acid load. As the cation exchange capacity (meq dm -3) and base saturation were lower in the sites from the catchment receiving lower deposition, these streams may be more vulnerable to acidification in the near future. The high concentration of base cations in non-exchangeable fractions may also buffer against acidification as it is likely that some of these pools will become exchangeable with time.

  3. Decontamination effects of detergents on the market for radioactive surface contamination. Their comparative test (2)

    Energy Technology Data Exchange (ETDEWEB)

    Miyabe, Kenjiro; Takasaki, Koji; Horiuchi, N. [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan). Tokai Works; Yasunaka, Hideo; Izumi, Yuichi [Japan Environment Research Co. Ltd., Tokyo (Japan)

    1999-04-01

    There happens frequently radioactive surface contamination on human body and skin under radiation works in controlled area. The surface contamination should be removed from the body and the skin as soon as possible for radiation control and exposure management. Titanium oxide paste, which is reserved as detergent for radioactive surface contamination, has satisfactory results and reliability for decontamination effects. The titanium oxide paste, however, has a short preservation period, and must be exchanged and supplied every several months. Decontamination tests for 22 kinds of detergents on the market were carried out with swine skin and radiation materials, Cs-137 and Ru-106. Radiation solution of Cs-137 or Ru-106 was dropped on the swine skin sample, which was left for 5 min or 40 min as it is. Radioactivity of the sample was measured before and after washing of the detergents. Decontamination effects of the detergents for Cs-137 were similar to those for Ge-144 which were tested in the previous year. The decontamination effects for Ru-106, however, were remarkably lower than those for both cases of Cs-137 and Ge-144. (M. Suetake)

  4. Mathematical simulation of sediment and contaminant transport in surface waters. Annual report, October 1977--September 1978

    International Nuclear Information System (INIS)

    Onishi, Y.; Arnold, E.M.; Serne, R.J.; Cowan, C.E.; Thompson, F.L.; Mayer, D.W.

    1979-01-01

    Various pathways exist for exposure of humans and biota to radioactive materials released from nuclear facilities. Hydrologic transport (liquid pathway) is one element in the evaluation of the total radiation dose to man. Mathematical models supported by well-planned field data collection programs can be useful tools in assessing the hydrologic transport and ultimate fate of radionuclides. Radionuclides with high distribution coefficients or radionuclides in surface waters with high suspended sediment concentrations are, to a great extent, adsorbed by river and marine sediments. Thus, otherwise dilute contaminants are concentrated. Contaminated sediments may be deposited on the river and ocean beds creating a significant pathway to man. Contaminated bed sediment in turn may become a long-term source of pollution through desorption and resuspension. In order to assess migration and accumulation of radionuclides in surface waters, mathematical models must correctly simulate essential mechanisms of radionuclide transport. The objectives of this study were: (1) to conduct a critical review of (a) radionuclide transport models as well as sediment transport and representative water quality models in rivers, estuaries, oceans, lakes, and reservoirs, and (b) adsorption and desorption mechanisms of radionuclides with sediments in surface waters; (2) to synthesize a mathematical model capable of predicting short- and long-term transport and accumulation of radionuclides in marine environments

  5. Mitigation of cesium and cobalt contamination on the surfaces of RAM packages

    International Nuclear Information System (INIS)

    Krumhansl, J.; Bonhomme, F.; McConnell, P.; Kapoor, A.

    2004-01-01

    Techniques for mitigating the adsorption of 137 Cs and 60 Co on metal surfaces (e.g., RAM packages) exposed to contaminated water (e.g., spent-fuel pools) has been developed and experimentally verified. The techniques are also effective in removing some of the 60 Co and 137 Cs that may have been adsorbed on the surfaces after removal from the contaminated water. The principle for the 137 Cs mitigation technique is based upon ion-exchange processes. In contrast, 60 Co contamination primarily resides in minute particles of CRUD that become lodged on cask surfaces. CRUD is an insoluble Fe-Ni-Cr oxide that forms colloidal-sized particles as stainless steels corrode. Because of the similarity between Ni +2 and Co +2 , CRUD is able to scavenge and retain traces of cobalt as it forms. A number of organic compounds have a great specificity for combining with nickel and cobalt. Ongoing research is investigating the effectiveness of chemical complexing agent, EDTA, with regard to its ability to dissolve the host phase (CRUD) thereby liberating the entrained 60Co into a solution where it can be rinsed away

  6. Trench 'bathtubbing' and surface plutonium contamination at a legacy radioactive waste site.

    Science.gov (United States)

    Payne, Timothy E; Harrison, Jennifer J; Hughes, Catherine E; Johansen, Mathew P; Thiruvoth, Sangeeth; Wilsher, Kerry L; Cendón, Dioni I; Hankin, Stuart I; Rowling, Brett; Zawadzki, Atun

    2013-01-01

    Radioactive waste containing a few grams of plutonium (Pu) was disposed between 1960 and 1968 in trenches at the Little Forest Burial Ground (LFBG), near Sydney, Australia. A water sampling point installed in a former trench has enabled the radionuclide content of trench water and the response of the water level to rainfall to be studied. The trench water contains readily measurable Pu activity (~12 Bq/L of (239+240)Pu in 0.45 μm-filtered water), and there is an associated contamination of Pu in surface soils. The highest (239+240)Pu soil activity was 829 Bq/kg in a shallow sample (0-1 cm depth) near the trench sampling point. Away from the trenches, the elevated concentrations of Pu in surface soils extend for tens of meters down-slope. The broader contamination may be partly attributable to dispersion events in the first decade after disposal, after which a layer of soil was added above the trenched area. Since this time, further Pu contamination has occurred near the trench-sampler within this added layer. The water level in the trench-sampler responds quickly to rainfall and intermittently reaches the surface, hence the Pu dispersion is attributed to saturation and overflow of the trenches during extreme rainfall events, referred to as the 'bathtub' effect.

  7. Detection of fecal contamination on beef meat surfaces using handheld fluorescence imaging device (HFID)

    Science.gov (United States)

    Oh, Mirae; Lee, Hoonsoo; Cho, Hyunjeong; Moon, Sang-Ho; Kim, Eun-Kyung; Kim, Moon S.

    2016-05-01

    Current meat inspection in slaughter plants, for food safety and quality attributes including potential fecal contamination, is conducted through by visual examination human inspectors. A handheld fluorescence-based imaging device (HFID) was developed to be an assistive tool for human inspectors by highlighting contaminated food and food contact surfaces on a display monitor. It can be used under ambient lighting conditions in food processing plants. Critical components of the imaging device includes four 405-nm 10-W LEDs for fluorescence excitation, a charge-coupled device (CCD) camera, optical filter (670 nm used for this study), and Wi-Fi transmitter for broadcasting real-time video/images to monitoring devices such as smartphone and tablet. This study aimed to investigate the effectiveness of HFID in enhancing visual detection of fecal contamination on red meat, fat, and bone surfaces of beef under varying ambient luminous intensities (0, 10, 30, 50 and 70 foot-candles). Overall, diluted feces on fat, red meat and bone areas of beef surfaces were detectable in the 670-nm single-band fluorescence images when using the HFID under 0 to 50 foot-candle ambient lighting.

  8. Mitigation of cesium and cobalt contamination on the surfaces of RAM packages

    Energy Technology Data Exchange (ETDEWEB)

    Krumhansl, J.; Bonhomme, F.; McConnell, P. [Sandia National Labs., Albuquerque (United States); Kapoor, A. [U.S. Dept. of Energy, Albuquerque (United States)

    2004-07-01

    Techniques for mitigating the adsorption of {sup 137}Cs and {sup 60}Co on metal surfaces (e.g., RAM packages) exposed to contaminated water (e.g., spent-fuel pools) has been developed and experimentally verified. The techniques are also effective in removing some of the {sup 60}Co and {sup 137}Cs that may have been adsorbed on the surfaces after removal from the contaminated water. The principle for the {sup 137}Cs mitigation technique is based upon ion-exchange processes. In contrast, {sup 60}Co contamination primarily resides in minute particles of CRUD that become lodged on cask surfaces. CRUD is an insoluble Fe-Ni-Cr oxide that forms colloidal-sized particles as stainless steels corrode. Because of the similarity between Ni{sup +2} and Co{sup +2}, CRUD is able to scavenge and retain traces of cobalt as it forms. A number of organic compounds have a great specificity for combining with nickel and cobalt. Ongoing research is investigating the effectiveness of chemical complexing agent, EDTA, with regard to its ability to dissolve the host phase (CRUD) thereby liberating the entrained 60Co into a solution where it can be rinsed away.

  9. Viral contamination of aerosol and surfaces through toilet use in health care and other settings.

    Science.gov (United States)

    Verani, Marco; Bigazzi, Roberto; Carducci, Annalaura

    2014-07-01

    The airborne spreading of enteric viruses can occur through the aerosol and droplets produced by toilet flushing. These can contaminate the surrounding environment, but few data exist to estimate the risk of exposure and infection. For this reason environmental monitoring of air and selected surfaces was carried out in 2 toilets of an office building and in 3 toilets of a hospital before and after cleaning operations. To reveal the presence of norovirus, enterovirus, rhinovirus, human rotavirus, and Torque teno virus and to quantify human adenovirus and bacteria counts, molecular and cultural methods were used. On the whole, viruses were detected on 78% of surfaces and in 81% of aerosol. Among the researched viruses, only human adenovirus and Torque teno virus were found in both surface and air samples. In several cases the same adenovirus strain was concurrently found in all matrices. Bacterial counts were unrelated to viral presence and cleaning did not seem to substantially reduce contamination. The data collected in our study confirm that toilets are an important source of viral contamination, mainly in health care settings, where disinfection can have a crucial role in preventing virus spread. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  10. Identification of discharge zones and quantification of contaminant mass discharges into a local stream from a landfill in a heterogeneous geologic setting

    DEFF Research Database (Denmark)

    Milosevic, Nemanja; Thomsen, Nanna Isbak; Juhler, R.K.

    2012-01-01

    concentration levels. A comparison between mass balance for selected stream stretches and upscaled measurements of the contaminant discharge from groundwater into the stream indicated that only a small part of the actual contaminant discharge of the stream could be explained by the inflowing contaminant......Contaminants from Risby Landfill (Denmark) are expected to leach through the underlying geologic strata and eventually reach the local Risby Stream. Identification of the groundwater discharge zone was conducted systematically by an array of methods including studies on site geology....... The groundwater discharge was quantified by two methods: direct collection of discharged groundwater by seepage meters and calculations from measurement of streambed temperature gradients. The landfill impacted the stream seasonally during dry periods when concentrations in the stream reached groundwater...

  11. Predicting root zone soil moisture with satellite near-surface moisture data in semiarid environments

    Science.gov (United States)

    Manfreda, S.; Baldwin, D. C.; Keller, K.; Smithwick, E. A. H.; Caylor, K. K.

    2015-12-01

    One of the most critical variables in semiarid environment is the soil water content that represents a controlling factor for both ecological and hydrological processes. Soil moisture monitoring over large scales may be extremely useful, but it is limited by the fact that most of the available tools provides only surface measurements not representative of the effective amount of water stored in the subsurface. Therefore, a methodology able to infer root-zone soil moisture starting from surface measurements is highly desirable. Recently a new simplified formulation has been introduced to provide a formal description of the mathematical relationship between surface measurements and root-zone soil moisture (Manfreda et al., HESS 2014). This is a physically based approach derived from the soil water balance equation, where different soil water loss functions have been explored in order to take into account for the non-linear processes governing soil water fluxes. The study highlighted that the soil loss function is the key for such relationship that is therefore strongly influenced by soil type and physiological plant types. The new formulation has been tested on soil moisture based on measurements taken from the African Monsoon Multidisciplinary Analysis (AMMA) and the Soil Climate Analysis Network (SCAN) databases. The method sheds lights on the physical controls for soil moisture dynamics and on the possibility to use such a simplified method for the description of root-zone soil moisture. Furthermore, the method has been also couple with an Enasamble Kalman Filter (EnKF) in order to optimize its performances for the large scale monitoring based the new satellite near-surface moisture data (SMAP). The optimized SMAR-EnKF model does well in both wet and dry climates and across many different soil types (51 SCAN locations) providing a strategy for real-time soil moisture monitoring.

  12. Surface and subsurface characterization of uranium contamination at the Fernald environmental management site

    International Nuclear Information System (INIS)

    Schilk, A.J.; Perkins, R.W.; Abel, K.H.; Brodzinski, R.L.

    1993-04-01

    The past operations of uranium production and support facilities at several Department of Energy (DOE) sites have occasionally resulted in the local contamination of some surface and subsurface soils, and the three-dimensional distribution of the uranium at these sites must be thoroughly characterized before any effective remedial protocols can be established. To this end, Pacific Northwest Laboratory (PNL) has been tasked by the DOE's Office of Technology Development with adapting, developing, and demonstrating technologies for the measurement of uranium in surface and subsurface soils at the Fernald Uranium in Soils Integrated Demonstration site. These studies are detailed in this report

  13. Study of luminous phenomena observed on contaminated metallic surfaces submitted to high RF fields

    International Nuclear Information System (INIS)

    Maissa, S.; Junquera, T.; Fouaidy, M.; Le Goff, A.; Bonin, B.; Luong, M.; Safa, H.; Tan, J.

    1995-01-01

    The RF field emission from a sample subjected to high RF fields in a copper cavity has been investigated. The study is focused on the luminous emissions occurring on the RF surface simultaneously with the electron emission. The optical apparatus attached to the cavity permits to observe the evolution of the emitters and the direct effects of the surface conditioning. Also, the parameters of the emitted radiation (intensity, glowing duration, spectral distribution) may provide additional informations on the field emission phenomena. Some results concerning samples intentionally contaminated with particles (metallic or dielectric) are presented. (K.A.)

  14. Characteristics of aerobic and anaerobic ammonium-oxidizing bacteria in the hyporheic zone of a contaminated river.

    Science.gov (United States)

    Wang, Ziyuan; Qi, Yun; Wang, Jun; Pei, Yuansheng

    2012-09-01

    Both β-proteobacterial aerobic ammonium-oxidizing bacteria (AOB) and anaerobic ammonium-oxidizing (ANAMMOX) bacteria were investigated in the hyporheic zone of a contaminated river in China containing high ammonium levels and low chemical oxygen demand. Fluorescence in-situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE) and cloning-sequencing were employed in this study. FISH analysis illustrated that AOB (average population of 3.5 %) coexisted with ANAMMOX bacteria (0.7 %). The DGGE profile revealed a high abundance and diversity of bacteria at the water-air-soil interface rather than at the water-soil interface. The redundancy analysis correlated analysis showed that the diversity of ANAMMOX bacteria was positively related to the redox potential. The newly detected sequences of ANAMMOX organisms principally belonged to the genus Candidatus "Brocadia", while most ammonia monooxygenase subunit-A gene amoA sequences were affiliated with Nitrosospira and Nitrosomonas. These results suggest that the water-air-soil interface performs an important function in the nitrogen removal process and that the bioresources of AOB and ANAMMOX bacteria can potentially be utilized for the eutrophication of rivers.

  15. Spectroscopic and Microscopic Characterization of Contaminant Uptake and Retention by Carbonates in the Soil and Vadose Zone

    International Nuclear Information System (INIS)

    Reeder, Richard J.; Fisher, Nicholas S.; Hess, Wayne P.; Beck, Kenneth M.

    2003-01-01

    The research focus of this previous EMSP grant was assessment of the role that carbonate minerals play in the uptake and sequestration of metal and radionuclide contaminants in soils and the vadose zone for conditions relevant to the Hanford Site and other sites in the DOE Complex. The project was a collaboration among researchers at SUNY-Stony Brook and EMSL/PNNL. Carbonates, particularly calcite, are present in the Hanford subsurface as grain coatings, disseminated particles, and dense caliche layers. Calcite is also predicted to be forming beneath leaking tanks. A range of metal and radionuclide species that pose risks at Hanford and other DOE sites were considered, including U(VI), Cr(CV), Cs, Pb(II), and selected lanthanides (as models for trivalent actinides). Batch sorption and co-precipitation experiments of these metals with pre-equilibrated calcite and selected uptake experiments on natural caliche formed the basis to determine the mechanisms of metal/radionuclide binding and to assess the effect on the stability of the sorbed species and the potential for remobilization. Our results provide ne information that can benefit DOE clean-up methodology and potentially provide new approaches for uptake of selected heavy metals

  16. Methane Bubbles Transport Particles From Contaminated Sediment to a Lake Surface

    Science.gov (United States)

    Delwiche, K.; Hemond, H.

    2017-12-01

    Methane bubbling from aquatic sediments has long been known to transport carbon to the atmosphere, but new evidence presented here suggests that methane bubbles also transport particulate matter to a lake surface. This transport pathway is of particular importance in lakes with contaminated sediments, as bubble transport could increase human exposure to toxic metals. The Upper Mystic Lake in Arlington, MA has a documented history of methane bubbling and sediment contamination by arsenic and other heavy metals, and we have conducted laboratory and field studies demonstrating that methane bubbles are capable of transporting sediment particles over depths as great as 15 m in Upper Mystic Lake. Methane bubble traps were used in-situ to capture particles adhered to bubble interfaces, and to relate particle mass transport to bubble flux. Laboratory studies were conducted in a custom-made 15 m tall water column to quantify the relationship between water column height and the mass of particulate transport. We then couple this particle transport data with historical estimates of ebullition from Upper Mystic Lake to quantify the significance of bubble-mediated particle transport to heavy metal cycling within the lake. Results suggest that methane bubbles can represent a significant pathway for contaminated sediment to reach surface waters even in relatively deep water bodies. Given the frequent co-occurrence of contaminated sediments and high bubble flux rates, and the potential for human exposure to heavy metals, it will be critical to study the significance of this transport pathway for a range of sediment and contaminant types.

  17. Metals Accumulation and Leaf Surface Anatomy of Murdannia spectabilis Growing in Zn/Cd Contaminated Soil

    Directory of Open Access Journals (Sweden)

    Ladawan Rattanapolsan

    2013-07-01

    Full Text Available Murdannia spectabilis (Kurz Faden was identified as a Zn/Cd hyperaccumulative plant. Leaf surface anatomy of the plant growing in non-contaminated soil (control and Zn/Cd contaminated soil,was studied and compared by a light microscopy and scanning electron microscopy combined with Energy-dispersive X-ray spectroscopy(SEM/EDS. The similarities were reticulate cuticle on epidermises, uniform polygonal cell, stomatal arrangement in six surrounding subsidiary cells, and submarginal sclerenchyma. The dissimilarities were uniserate trichomes spreading on both adaxial and abaxial epidermis of the plants growing in non-contaminated soil, whereas the uniserate trichomes were only on the submarginal-adaxial epidermis of the control plants. The trichomes on leaves of the plants growing in non-contaminated soil were found to have both uniseriate non-glandular and uniseriate glandular trichomes;whereas, leaves of the plants growing in the contaminated soil were merely non-glandular trichomes. The different shape and location of trichomes, the number of stomata and trichome indicated the effect of Zn and Cd on M. spectabilis. The higher percentages of Zn and Cd in the vascular bundle than in the cross section and epidermis areas showed both solutes could move along each route, with diffusion through the symplast and apoplast. The increase of Ca in M. spectabilis growing in Zn/Cd contaminated soil corresponded to the Zn and Cd distributed in the leaves. Zn K-edge and S K-edge XANES spectra proposed that Zn2+ ions were accumulated and/or adsorbed on the epidermis of the tuber, and then absorbed into the root and transport to the xylem. The double peaks of Zn-cysteine in the leaf samples proposed the metal sequestration was by sulphur proteins.

  18. Degree of bacterial contamination and antibiotic susceptibility pattern of isolates from housekeeping surfaces in operating rooms and surgical wards at Jimma University Specialized Hospital, south west Ethiopia.

    Science.gov (United States)

    Genet, Chalachew; Kibru, Gebre; Hemalatha, Kannan

    2012-01-01

    The role of the hospital environment as a reservoir of potential pathogens has received increasing attention. There are several reports demonstrating contamination of a wide variety of environmental sites in operating rooms (ORs) and surgical wards (SWs) which lead to nosocomial spread. To determine the degree of bacterial contamination and antibiotic susceptibility pattern of isolates from floor and tabletop surfaces in ORs and SWs at Jimma University Specialized Hospital (JUSH). A cross sectional study was conducted on 144 floor and tabletop surfaces from October to January 2009/2010. Samples were investigated for identification of bacterial species following standard procedures and antimicrobial susceptibility tests were performed using disc diffusion technique. The data was analyzed using SPSS version 16 and compared with the proposed standard value. The mean aerobic colony counts (ACCs) for tabletop surfaces (34 CFU/cm2) and floors (19CFU/cm2) in SWs were significantly higher than the set ACC standard for hand contact surfaces (< 5 CFU/cm2) P < 0.00. The ACCs obtained from tabletop surfaces (6.2 CFU/cm2) and floors (10.1CFU/cm2) in ORs were also exceeding the standard. Over 55% of gram negative bacteria were identified from Critical Zone of ORs. Staphylococcus aureus was the must frequently isolated bacterium accounting 33.3% followed by Escherichia coli and Klebsiella spp each with 11.1%. Moreover, S. aureus showed 100% resistance to methicillin and multidrug resistant Enterobacteriaceae were also seen in more than 90 % of isolates. An increased bacterial contamination was measured in both ORs and SWs of the JUSH and the isolated bacteria were also resistant for most of the antibiotics used as a treatment options in the study area. Therefore, appropriate infection control measures needs to be taken to keep the contamination level within the proposed standard.

  19. Bearing splitting and near-surface source ranging in the direct zone of deep water

    Science.gov (United States)

    Wu, Jun-Nan; Zhou, Shi-Hong; Peng, Zhao-Hui; Zhang, Yan; Zhang, Ren-He

    2016-12-01

    Sound multipath propagation is very important for target localization and identification in different acoustical zones of deep water. In order to distinguish the multipath characteristics in deep water, the Northwest Pacific Acoustic Experiment was conducted in 2015. A low-frequency horizontal line array towed at the depth of around 150 m on a receiving ship was used to receive the noise radiated by the source ship. During this experiment, a bearing-splitting phenomenon in the direct zone was observed through conventional beamforming of the horizontal line array within the frequency band 160 Hz-360 Hz. In this paper, this phenomenon is explained based on ray theory. In principle, the received signal in the direct zone of deep water arrives from two general paths including a direct one and bottom bounced one, which vary considerably in arrival angles. The split bearings correspond to the contributions of these two paths. The bearing-splitting phenomenon is demonstrated by numerical simulations of the bearing-time records and experimental results, and they are well consistent with each other. Then a near-surface source ranging approach based on the arrival angles of direct path and bottom bounced path in the direct zone is presented as an application of bearing splitting and is verified by experimental results. Finally, the applicability of the proposed ranging approach for an underwater source within several hundred meters in depth in the direct zone is also analyzed and demonstrated by simulations. Project supported by the Program of One Hundred Talented People of the Chinese Academy of Sciences and the National Natural Science Foundation of China (Grant Nos. 11434012 and 41561144006).

  20. Limits determination of microbial contamination present on surfaces from a pharmaceutical microbiology district reference laboratory

    Directory of Open Access Journals (Sweden)

    Natalia Charry

    2016-06-01

    Full Text Available Context: The bioburden present on the pharmaceutical microbiology laboratory’s surfaces, may increase the risk of cross-contamination when analytical tests are being carried out; periodic monitoring allows to set limits that reduce the risk. Aims: To determinate the limits of bioburden present on seven surfaces of the pharmaceutical microbiology laboratory, after the cleaning and disinfection process. Methods: The swabbing method was used for sampling. With a 25 cm2 stencil and a sterile swab, a sample was taken, passing the swab over five points of every surface chosen. A total aerobic microbial count and a total yeast and mold count was done. Finally, the average and the standard deviation of the counts was obtained. Results: The average from the counts obtained on each surface selected for the study, were below the recommended limits by international entities like the World Health Organization and the European Union, between others; also, the results generated in this study, allow to classify the biosafety cabinet as an ISO 5 area and the other areas as ISO 7. Conclusions: Bioburden levels on the tested surfaces are considered low, reducing the risk of cross-contamination, which could have a negative impact on laboratory’s activities. Also, it follows that disinfectant concentration used, is effectively.

  1. Accuracy Analysis of a Robotic Radionuclide Inspection and Mapping System for Surface Contamination

    International Nuclear Information System (INIS)

    Mauer, Georg F.; Kawa, Chris

    2008-01-01

    The mapping of localized regions of radionuclide contamination in a building can be a time consuming and costly task. Humans moving hand-held radiation detectors over the target areas are subject to fatigue. A contamination map based on manual surveys can contain significant operator-induced inaccuracies. A Fanuc M16i light industrial robot has been configured for installation on a mobile aerial work platform, such as a tall forklift. When positioned in front of a wall or floor surface, the robot can map the radiation levels over a surface area of up to 3 m by 3 m. The robot's end effector is a commercial alpha-beta radiation sensor, augmented with range and collision avoidance sensors to ensure operational safety as well as to maintain a constant gap between surface and radiation sensors. The accuracy and repeatability of the robotically conducted contamination surveys is directly influenced by the sensors and other hardware employed. This paper presents an in-depth analysis of various non-contact sensors for gap measurement, and the means to compensate for predicted systematic errors that arise during the area survey scans. The range sensor should maintain a constant gap between the radiation counter and the surface being inspected. The inspection robot scans the wall surface horizontally, moving down at predefined vertical intervals after each scan in a meandering pattern. A number of non-contact range sensors can be employed for the measurement of the gap between the robot end effector and the wall. The nominal gap width was specified as 10 mm, with variations during a single scan not to exceed ± 2 mm. Unfinished masonry or concrete walls typically exhibit irregularities, such as holes, gaps, or indentations in mortar joints. These irregularities can be sufficiently large to indicate a change of the wall contour. The responses of different sensor types to the wall irregularities vary, depending on their underlying principles of operation. We explored

  2. An investigation of fungal contamination on the surface of medicinal herbs in China.

    Science.gov (United States)

    Zheng, Run-Sheng; Wang, Wen-Li; Tan, Jing; Xu, Hui; Zhan, Ruo-Ting; Chen, Wei-Wen

    2017-01-01

    The dried parts of medicinal herbs are susceptible to the infection of fungi during pre- or post-harvest procedure. This study aimed to investigate the presence of fungi and their metabolites mycotoxins on the surface of medicinal herbs collected from China. Forty-five retail samples of 15 different medicinal herbs were collected from 3 different regions in China. Then the potential fungi were immediately washed off from the surface of each sample with 0.1% Tween-20 followed by incubation of the rinse on petri-dish with potato dextrose agar containing chloramphenicol at 28 °C. The obtained fungi were isolated as single colonies and then characterized by morphology and molecular identification using internal transcribed spacer (ITS) sequencing with extracted DNA. Meanwhile, the mycotoxin-producing potential of the isolates was studied by liquid chromatography-tandem mass spectrometry (LC-MS/MS). A total of 126 fungi were identified from the surface of samples by morphology and ITS sequencing, with Aspergillus and Penicillium genera as the predominant contaminants. The mycotoxin-producing potential analysis showed that 6 of 8 A. versicolor isolates could produce sterigmatocystin. All 3 A. aculeatus isolates produced ochratoxin A, but only 1 of 3 A. flavus strains produced aflatoxins B 1 and B 2 without G 1 and G 2 . Although the sample contamination ratios were high (≥95.6%), there was no significant difference ( χ 2  = 1.05, P  = 1.0) among the samples from 3 regions, which demonstrates the prevalent fungal contamination in the herbal medicines. The prevalent contamination phenomenon of fungi and high potential risk of sterigmatocystin and ochratoxin A were observed in 45 medicinal herbs collected from China.

  3. Life histories, salinity zones, and sublethal contributions of contaminants to pelagic fish declines illustrated with a case study of San Francisco Estuary, California, USA

    Science.gov (United States)

    Brooks, Marjorie L.; Fleishman, Erica; Brown, Larry R.; Lehman, Peggy W.; Werner, Inge; Scholz, Nathaniel; Michelmore, Carys; Loworn, James R.; Johnson, Michael L.; Schlenk, Daniel

    2012-01-01

    Human effects on estuaries are often associated with major decreases in abundance of aquatic species. However, remediation priorities are difficult to identify when declines result from multiple stressors with interacting sublethal effects. The San Francisco Estuary offers a useful case study of the potential role of contaminants in declines of organisms because the waters of its delta chronically violate legal water quality standards; however, direct effects of contaminants on fish species are rarely observed. Lack of direct lethality in the field has prevented consensus that contaminants may be one of the major drivers of coincident but unexplained declines of fishes with differing life histories and habitats (anadromous, brackish, and freshwater). Our review of available evidence indicates that examining the effects of contaminants and other stressors on specific life stages in different seasons and salinity zones of the estuary is critical to identifying how several interacting stressors could contribute to a general syndrome of declines. Moreover, warming water temperatures of the magnitude projected by climate models increase metabolic rates of ectotherms, and can hasten elimination of some contaminants. However, for other pollutants, concurrent increases in respiratory rate or food intake result in higher doses per unit time without changes in the contaminant concentrations in the water. Food limitation and energetic costs of osmoregulating under altered salinities further limit the amount of energy available to fish; this energy must be redirected from growth and reproduction toward pollutant avoidance, enzymatic detoxification, or elimination. Because all of these processes require energy, bioenergetics methods are promising for evaluating effects of sublethal contaminants in the presence of other stressors, and for informing remediation. Predictive models that evaluate the direct and indirect effects of contaminants will be possible when data become

  4. Resistance to disinfection of a polymicrobial association contaminating the surface of elastomeric dental impressions.

    Science.gov (United States)

    Giammanco, Giovanni M; Melilli, Dario; Rallo, Antonio; Pecorella, Sonia; Mammina, Caterina; Pizzo, Giuseppe

    2009-04-01

    The aim of this study was to evaluate the ability to resist disinfection of a polymicrobial association contaminating the surface of dental impressions obtained with two different elastomers: a polyether (Impregum) and an addition-polymerized silicone (Elite). Impressions were contaminated with a mixture of three biofilm-forming microorganisms (Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans) and disinfected immediately after contamination, or after microbial layers were allowed to develop during a six-hour storage. Two commercial disinfectants were tested: MD 520 containing 0.5% glutaraldehyde and Sterigum Powder without glutaraldehyde. Residual contamination was recovered by mechanical rinsing immediately after disinfection and after a six-hour storage of disinfected impressions, and assessed by colony counting. Both disinfectants tested were shown to be effective in reducing the microbial presence on the impression materials, achieving at least a 102 reduction of microbial counts compared to water rinsing. However, Sterigum was generally less effective on the Elite elastomer and could not grant disinfection on six-hour aged P. aeruginosa and C. albicans microbial layers. The results of this study suggest that the materials used for the impressions influence the efficacy of disinfection. Disinfectants should be tested according to conditions encountered in everyday clinical practice and the need for immediate disinfection of impressions should be clearly indicated by manufacturers.

  5. Occurrence and behavior of emerging contaminants in surface water and a restored wetland.

    Science.gov (United States)

    Matamoros, Víctor; Arias, Carlos A; Nguyen, Loc Xuan; Salvadó, Victòria; Brix, Hans

    2012-08-01

    Pollution mitigation is an important target for restored wetlands, and although there is much information in relation to nutrient removal, little attention has been paid to emerging contaminants. This paper reports on the occurrence and attenuation capacity of 17 emerging contaminants in a restored wetland and two rivers in North-East Denmark. The compounds belong to the groups of pharmaceuticals, fragrances, antiseptics, fire retardants, pesticides, and plasticizers. Concentrations in surface waters ranged from 2 to 1476 ng L(-1). The compounds with the highest concentrations were diclofenac, 2-methyl-4-chlorophenoxyacetic acid (MCPA), caffeine, and tris(2-chloroethyl) phosphate (TCEP). The herbicide concentrations increased after a rain-fall event, demonstrating the agricultural run-off origin of these compounds, whereas the concentration of the other emerging contaminants was rather conservative. The mitigation capacity of the restored wetland for the compounds ranged from no attenuation to 84% attenuation (19% on average). Hence, restored wetlands may be considered as a feasible alternative for mitigating emerging contaminants from river waters. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Uptake of radionuclides by wheat roots with respect to location of contamination below the surface

    International Nuclear Information System (INIS)

    Suvornmongkhol, Narumon.

    1996-01-01

    The behaviour of 85 Sr, 137 Cs, 54 Mn and 60 Co in terms of plant availability in near surface soil and their root uptake was studied as a function of the location of contamination in the soil profile. Wheat (Triticum aestivum) was employed and the study programme involved both column and hydroponic studies. In the column studies, columns were packed with sandy soil, and either homogeneously or discretely contaminated with the radionuclides, and the water table maintained manually at 3 cm from the bottom. In the discrete contamination, the location of contamination was varied (0-5, 25-30 or 45-50 cm from the top). Wheat plants were grown to maturity in these columns, and harvested at different growth stages to examine radioactivity uptake and its subsequent translocation within the plants. The movement of radionuclides within the soil as well as the soil physicochemical properties were also investigated. The short term uptake kinetics of the hydroponically grown plants during ontogenesis were also studied, both with excised roots and intact plants. The excised root experiment was aimed at investigating the radionuclide by roots of different orders. (author)

  7. The SMAP Level 4 Surface and Root-zone Soil Moisture (L4_SM) Product

    Science.gov (United States)

    Reichle, Rolf; Crow, Wade; Koster, Randal; Kimball, John

    2010-01-01

    The Soil Moisture Active and Passive (SMAP) mission is being developed by NASA for launch in 2013 as one of four first-tier missions recommended by the U.S. National Research Council Committee on Earth Science and Applications from Space in 2007. The primary science objectives of SMAP are to enhance understanding of land surface controls on the water, energy and carbon cycles, and to determine their linkages. Moreover, the high resolution soil moisture mapping provided by SMAP has practical applications in weather and seasonal climate prediction, agriculture, human health, drought and flood decision support. In this paper we describe the assimilation of SMAP observations for the generation of the planned SMAP Level 4 Surface and Root-zone Soil Moisture (L4_SM) product. The SMAP mission makes simultaneous active (radar) and passive (radiometer) measurements in the 1.26-1.43 GHz range (L-band) from a sun-synchronous low-earth orbit. Measurements will be obtained across a 1000 km wide swath using conical scanning at a constant incidence angle (40 deg). The radar resolution varies from 1-3 km over the outer 70% of the swath to about 30 km near the center of the swath. The radiometer resolution is 40 km across the entire swath. The radiometer measurements will allow high-accuracy but coarse resolution (40 km) measurements. The radar measurements will add significantly higher resolution information. The radar is however very sensitive to surface roughness and vegetation structure. The combination of the two measurements allows optimal blending of the advantages of each instrument. SMAP directly observes only surface soil moisture (in the top 5 cm of the soil column). Several of the key applications targeted by SMAP, however, require knowledge of root zone soil moisture (approximately top 1 m of the soil column), which is not directly measured by SMAP. The foremost objective of the SMAP L4_SM product is to fill this gap and provide estimates of root zone soil moisture

  8. Morphology and Differentiation of MG63 Osteoblast Cells on Saliva Contaminated Implant Surfaces

    Directory of Open Access Journals (Sweden)

    Neda Shams

    2015-11-01

    Full Text Available Objectives: Osteoblasts are the most important cells in the osseointegration process. Despite years of study on dental Implants, limited studies have discussed the effect of saliva on the adhesion process of osteoblasts to implant surfaces. The aim of this in vitro study was to evaluate the effect of saliva on morphology and differentiation of osteoblasts attached to implant surfaces.Materials and Methods: Twelve Axiom dental implants were divided into two groups. Implants of the case group were placed in containers, containing saliva, for 40 minutes. Then, all the implants were separately stored in a medium containing MG63 human osteoblasts for a week. Cell morphology and differentiation were assessed using a scanning electron microscope and their alkaline phosphatase (ALP activity was determined. The t-test was used to compare the two groups.Results: Scanning electron microscopic observation of osteoblasts revealed round or square cells with fewer and shorter cellular processes in saliva contaminated samples, whereas elongated, fusiform and well-defined cell processes were seen in the control group. ALP level was significantly lower in case compared to control group (P<0.05.Conclusion: Saliva contamination alters osteoblast morphology and differentiation and may subsequently interfere with successful osseointegration. Thus, saliva contamination of bone and implant must be prevented or minimized.

  9. Removal of contaminated concrete surfaces by microwave heating: Phase 1 results

    International Nuclear Information System (INIS)

    White, T.L.; Grubb, R.G.; Pugh, L.P.; Foster, D. Jr.; Box, W.D.

    1992-01-01

    Oak Ridge National Laboratory (ORNL) is developing a microwave heating process to remove radiologically contaminated surface layers from concrete. The microwave energy is directed at the concrete surface and heats the concrete and free water present in the concrete matrix. Continued heating produces steam-pressure-induced mechanical stresses that cause the concrete surface to burst. The concrete particles from this steam explosion are small enough to be removed by a vacuum system, yet less than 1% of the debris is small enough to pose an airborne contamination hazard. The first phase of this program has demonstrated reliable removal of noncontaminated concrete surfaces at frequencies of 2.45 GHz and 10.6 GHz. Continuous concrete removal rates of 1.07 cm 3 /s with 5.2 kW of 2.45.-GHz power and 2.11 cm 3 /s with 3.6 kW of 10.6-GHz power have been demonstrated. Figures-of-merit for microwave removal of concrete have been calculated to be 0.21 cm 3 /s/kW at 2.45 GHz and 0.59 cm 3 /s/kW at 10.6 GHz. The amount of concrete removed in a single pass can be controlled by choosing the frequency and power of the microwave system

  10. Eradication of high viable loads of Listeria monocytogenes contaminating food-contact surfaces

    Directory of Open Access Journals (Sweden)

    Silvia ede Candia

    2015-07-01

    Full Text Available This study demonstrates the efficacy of cold gaseous ozone treatments at low concentrations in the eradication of high Listeria monocytogenes viable cell loads from glass, polypropylene, stainless steel and expanded polystyrene food-contact surfaces. Using a step by step approach, involving the selection of the most resistant strain-surface combinations, 11 Listeria spp. strains resulted inactivated by a continuous ozone flow at 1.07 mg m-3 after 24 or 48 h of cold incubation, depending on both strain and surface evaluated. Increasing the inoculum level to 9 log CFU coupon-1, the best inactivation rate was obtained after 48h of treatment at 3.21 mg m-3 ozone concentration when cells were deposited onto stainless steel and expanded polystyrene coupons, resulted the most resistant food-contact surfaces in the previous assays.The addition of naturally microbiologically contaminated meat extract to a high load of L. monocytogenes LMG 23775 cells, the most resistant strain out of the 11 assayed Listeria spp. strains, led to its complete inactivation after four days of treatment.To the best of our knowledge, this is the first report describing the survival of L. monocytogenes and the effect of ozone treatment under cold storage conditions on expanded polystyrene, a commonly-used material in food packaging. These results could be useful for reducing pathogen cross-contamination phenomena during cold food storage.

  11. Quantifying potential sources of surface water contamination with Campylobacter jejuni and Campylobacter coli.

    Science.gov (United States)

    Mughini-Gras, Lapo; Penny, Christian; Ragimbeau, Catherine; Schets, Franciska M; Blaak, Hetty; Duim, Birgitta; Wagenaar, Jaap A; de Boer, Albert; Cauchie, Henry-Michel; Mossong, Joel; van Pelt, Wilfrid

    2016-09-15

    Campylobacter is the most common causative agent of human bacterial gastroenteritis and is frequently found in surface water, where it indicates recent contamination with animal faeces, sewage effluent, and agricultural run-off. The contribution of different animal reservoirs to surface water contamination with Campylobacter is largely unknown. In the Netherlands, the massive poultry culling to control the 2003 avian influenza epidemic coincided with a 44-50% reduction in human campylobacteriosis cases in the culling areas, suggesting substantial environment-mediated spread of poultry-borne Campylobacter. We inferred the origin of surface water Campylobacter jejuni and Campylobacter coli strains in Luxembourg and the Netherlands, as defined by multilocus sequence typing, by comparison to strains from poultry, pigs, ruminants, and wild birds, using the asymmetric island model for source attribution. Most Luxembourgish water strains were attributed to wild birds (61.0%), followed by poultry (18.8%), ruminants (15.9%), and pigs (4.3%); whereas the Dutch water strains were mainly attributed to poultry (51.7%), wild birds (37.3%), ruminants (9.8%), and pigs (1.2%). Attributions varied over seasons and surface water types, and geographical variation in the relative contribution of poultry correlated with the magnitude of poultry production at either the national or provincial level, suggesting that environmental dissemination of Campylobacter from poultry farms and slaughterhouses can be substantial in poultry-rich regions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Suitability of artificial sweeteners as indicators of raw wastewater contamination in surface water and groundwater.

    Science.gov (United States)

    Tran, Ngoc Han; Hu, Jiangyong; Li, Jinhua; Ong, Say Leong

    2014-01-01

    There is no quantitative data on the occurrence of artificial sweeteners in the aquatic environment in Southeast Asian countries, particularly no information on their suitability as indicators of raw wastewater contamination on surface water and groundwater. This study provided the first quantitative information on the occurrence of artificial sweeteners in raw wastewater, surface water and groundwater in the urban catchment area in Singapore. Acesulfame, cyclamate, saccharin, and sucralose were ubiquitous in raw wastewater samples at concentrations in the range of ng/L-μg/L, while other sweeteners were not found or found only in a few of the raw wastewater samples. Residential and commercial effluents were demonstrated to be the two main sources of artificial sweeteners entering the municipal sewer systems. Relatively higher concentrations of the detected sweeteners were frequently found in surface waters at the sampling sites located in the residential/commercial areas. No significant difference in the concentrations of the detected sweeteners in surface water or groundwater was noted between wet and dry weather conditions (unpaired T-test, p> 0.05). Relatively higher concentrations and detection frequencies of acesulfame, cyclamate and saccharin in surface water samples were observed at the potentially impacted sampling sites, while these sweeteners were absent in most of the background surface water samples. Similarly, acesulfame, cyclamate, and saccharin were found in most groundwater samples at the monitoring well (GW6), which is located close to known leaking sewer segment; whereas these were absent in the background monitoring well, which is located in the catchment with no known wastewater sources. Taken together, the results suggest that acesulfame, cyclamate, and saccharin can be used as potential indicators of raw wastewater contamination in surface water and groundwater. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Detection of aflatoxin and surface mould contaminated figs by using Fourier transform near-infrared reflectance spectroscopy.

    Science.gov (United States)

    Durmuş, Efkan; Güneş, Ali; Kalkan, Habil

    2017-01-01

    Aflatoxins are toxic metabolites that are mainly produced by members of the Aspergillus section Flavi on many agricultural products. Certain agricultural products such as figs are known to be high risk products for aflatoxin contamination. Aflatoxin contaminated figs may show a bright greenish yellow fluorescence (BGYF) under ultraviolet (UV) light at a wavelength of 365 nm. Traditionally, BGYF positive figs are manually selected by workers. However, manual selection depends on the expertise level of the workers and it may cause them skin-related health problems due to UV radiation. In this study, we propose a non-invasive approach to detect aflatoxin and surface mould contaminated figs by using Fourier transform near-infrared (FT-NIR) reflectance spectroscopy. A classification accuracy of 100% is achieved for classifying the figs into aflatoxin contaminated/uncontaminated and surface mould contaminated/uncontaminated categories. In addition, a strong correlation has been found between aflatoxin and surface mould. Combined with pattern classification methods, the NIR spectroscopy can be used to detect aflatoxin contaminated figs non-invasively. Furthermore, a positive correlation between surface mould and aflatoxin contamination leads to a promising alternative indicator for the detection of aflatoxin-contaminated figs. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  14. Innovative technology for expedited site remediation of extensive surface and subsurface contamination

    International Nuclear Information System (INIS)

    Audibert, J.M.E.; Lew, L.R.

    1994-01-01

    Large scale surface and subsurface contamination resulted from numerous releases of feed stock, process streams, waste streams, and final product at a major chemical plant. Soil and groundwater was contaminated by numerous compounds including lead, tetraethyl lead, ethylene dibromide, ethylene dichloride, and toluene. The state administrative order dictated that the site be investigated fully, that remedial alternative be evaluated, and that the site be remediated within a year period. Because of the acute toxicity and extreme volatility of tetraethyl lead and other organic compounds present at the site and the short time frame ordered by the regulators, innovative approaches were needed to carry out the remediation while protecting plant workers, remediation workers, and the public

  15. Advanced LWIR hyperspectral sensor for on-the-move proximal detection of liquid/solid contaminants on surfaces

    Science.gov (United States)

    Giblin, Jay P.; Dixon, John; Dupuis, Julia R.; Cosofret, Bogdan R.; Marinelli, William J.

    2017-05-01

    Sensor technologies capable of detecting low vapor pressure liquid surface contaminants, as well as solids, in a noncontact fashion while on-the-move continues to be an important need for the U.S. Army. In this paper, we discuss the development of a long-wave infrared (LWIR, 8-10.5 μm) spatial heterodyne spectrometer coupled with an LWIR illuminator and an automated detection algorithm for detection of surface contaminants from a moving vehicle. The system is designed to detect surface contaminants by repetitively collecting LWIR reflectance spectra of the ground. Detection and identification of surface contaminants is based on spectral correlation of the measured LWIR ground reflectance spectra with high fidelity library spectra and the system's cumulative binary detection response from the sampled ground. We present the concepts of the detection algorithm through a discussion of the system signal model. In addition, we present reflectance spectra of surfaces contaminated with a liquid CWA simulant, triethyl phosphate (TEP), and a solid simulant, acetaminophen acquired while the sensor was stationary and on-the-move. Surfaces included CARC painted steel, asphalt, concrete, and sand. The data collected was analyzed to determine the probability of detecting 800 μm diameter contaminant particles at a 0.5 g/m2 areal density with the SHSCAD traversing a surface.

  16. Surface tailored organobentonite enhances bacterial proliferation and phenanthrene biodegradation under cadmium co-contamination

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Asit [Future Industries Institute (formerly Centre for Environmental Risk Assessment and Remediation), University of South Australia, Mawson Lakes, SA 5095 (Australia); Indian Council of Agricultural Research (ICAR), Indian Institute of Soil Science, Bhopal (India); Biswas, Bhabananda [Future Industries Institute (formerly Centre for Environmental Risk Assessment and Remediation), University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), ACT Building, University of Newcastle, Callaghan, NSW 2308 (Australia); Sarkar, Binoy, E-mail: binoy.sarkar@unisa.edu.au [Future Industries Institute (formerly Centre for Environmental Risk Assessment and Remediation), University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), ACT Building, University of Newcastle, Callaghan, NSW 2308 (Australia); Patra, Ashok K. [Indian Council of Agricultural Research (ICAR), Indian Institute of Soil Science, Bhopal (India); Naidu, Ravi, E-mail: ravi.naidu@newcastle.edu.au [Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), ACT Building, University of Newcastle, Callaghan, NSW 2308 (Australia); Global Centre for Environmental Remediation (GCER), Faculty of Science and Information Technology, University of Newcastle, Callaghan, NSW 2308 (Australia)

    2016-04-15

    Co-contamination of soil and water with polycyclic aromatic hydrocarbon (PAH) and heavy metals makes biodegradation of the former extremely challenging. Modified clay-modulated microbial degradation provides a novel insight in addressing this issue. This study was conducted to evaluate the growth and phenanthrene degradation performance of Mycobacterium gilvum VF1 in the presence of a palmitic acid (PA)-grafted Arquad® 2HT-75-based organobentonite in cadmium (Cd)-phenanthrene co-contaminated water. The PA-grafted organobentonite (ABP) adsorbed a slightly greater quantity of Cd than bentonite at up to 30 mg L{sup −1} metal concentration, but its highly negative surface charge imparted by carboxylic groups indicated the potential of being a significantly superior adsorbent of Cd at higher metal concentrations. In systems co-contained with Cd (5 and 10 mg L{sup −1}), the Arquad® 2HT-75-modified bentonite (AB) and PA-grafted organobentonite (ABP) resulted in a significantly higher (72–78%) degradation of phenanthrene than bentonite (62%) by the bacterium. The growth and proliferation of bacteria were supported by ABP which not only eliminated Cd toxicity through adsorption but also created a congenial microenvironment for bacterial survival. The macromolecules produced during ABP–bacteria interaction could form a stable clay-bacterial cluster by overcoming the electrostatic repulsion among individual components. Findings of this study provide new insights for designing clay modulated PAH bioremediation technologies in mixed-contaminated water and soil. - Highlights: • Surface tailored organobentonite synthesised and characterised • Modified clay adsorbs Cd and reduces toxicity to Mycobacterium gilvum. • It creates congenial microenvironment for bacterial survival. • It enhances phenanthrene biodegradation in metal co-contaminated condition.

  17. Visible-light system for detecting doxorubicin contamination on skin and surfaces.

    Science.gov (United States)

    Van Raalte, J; Rice, C; Moss, C E

    1990-05-01

    A portable system that uses fluorescence stimulated by visible light to identify doxorubicin contamination on skin and surfaces was studied. When activated by violet-blue light in the 465-nm range, doxorubicin fluoresces, emitting orange-red light in the 580-nm range. The light source to stimulate fluorescence was a slide projector with a filter to selectively pass short-wave (blue) visible light. Fluorescence was both observed visually with viewing spectacles and photographed. Solutions of doxorubicin in sterile 0.9% sodium chloride injection were prepared in nine standard concentrations ranging from 2 to 0.001 mg/mL. Droplets of each admixture were placed on stainless steel, laboratory coat cloth, pieces of latex examination glove, bench-top absorbent padding, and other materials on which antineoplastics might spill or leak. These materials then were stored for up to eight weeks and photographed weekly. The relative ability of water, household bleach, hydrogen peroxide solution, and soap solution to deactivate doxorubicin was also measured. Finally, this system was used to inspect the antineoplastic-drug preparation and administration areas of three outpatient cancer clinics for doxorubicin contamination. Doxorubicin fluorescence was easily detectable with viewing spectacles when a slide projector was used as the light source. The photographic method was sensitive for doxorubicin concentrations from 2.0 to 0.001 mg/mL. Immersion of study materials in bleach for one minute eliminated detectable fluorescence. Doxorubicin contamination is detectable for at least eight weeks in the ambient environment. Probable doxorubicin contamination was detected in two of the three clinics surveyed. A safe, portable system that uses fluorescence stimulated by visible light is a sensitive method for detecting doxorubicin on skin and surfaces.

  18. Verification of surface contamination density standard using clearance automatic laser inspection system for objects from a nuclear power plant

    International Nuclear Information System (INIS)

    Sasaki, Michiya; Ogino, Haruyuki; Ichiji, Takeshi; Hattori, Takatoshi

    2008-01-01

    In the clearance level inspection in Japan, it is necessary to indicate that the activity level of the target object must be less than not only the clearance levels, but also the surface contamination density standards. The classification measurements for these two standards have been performed separately, and the GM survey meters based on beta-ray measurement have mainly been used for surface contamination density measurement so far. Recently the Clearance Automatic Laser Inspection System, named CLALIS, has been developed to estimate the low-level activity concentration. This system consists of 3-dimensional laser scanner for shape measurement and eight large NE102A plastic scintillation detectors for gamma-ray measurement, and it has been clarified that the CLALIS has adequate detection ability for clearance measurement of both metal scraps and concrete debris. In this study, we compared the surface contamination densities for a number of actual contaminated and non-contaminated objects generated inside from the radiation controlled area at the Kashiwazaki-Kariwa nuclear power station by using the CLALIS and the GM survey meter. As a result, since CLALIS could detect the surface contamination as well as the GM survey meter for all measurement targets, it was revealed that CLALIS can rationally achieve clearance level inspection in a single radiation measurement. The practicality of CLALIS in view of the detection limit and processing time was discussed by comparison with the usual radiation monitors for surface contamination measurement. (author)

  19. Effectiveness of disinfection with alcohol 70% (w/v of contaminated surfaces not previously cleaned

    Directory of Open Access Journals (Sweden)

    Maurício Uchikawa Graziano

    Full Text Available OBJECTIVE: To evaluate the disinfectant effectiveness of alcohol 70% (w/v using friction, without previous cleaning, on work surfaces, as a concurrent disinfecting procedure in Health Services. METHOD: An experimental, randomized and single-blinded laboratory study was undertaken. The samples were enamelled surfaces, intentionally contaminated with Serratia marcescens microorganisms ATCC 14756 106 CFU/mL with 10% of human saliva added, and were submitted to the procedure of disinfection WITHOUT previous cleaning. The results were compared to disinfection preceded by cleaning. RESULTS: There was a reduction of six logarithms of the initial microbial population, equal in the groups WITH and WITHOUT previous cleaning (p=0.440 and a residual microbial load ≤ 102 CFU. CONCLUSION: The research demonstrated the acceptability of the practice evaluated, bringing an important response to the area of health, in particular to Nursing, which most undertakes procedures of concurrent cleaning /disinfecting of these work surfaces.

  20. Effectiveness of disinfection with alcohol 70% (w/v of contaminated surfaces not previously cleaned

    Directory of Open Access Journals (Sweden)

    Maurício Uchikawa Graziano

    2013-04-01

    Full Text Available OBJECTIVE: To evaluate the disinfectant effectiveness of alcohol 70% (w/v using friction, without previous cleaning, on work surfaces, as a concurrent disinfecting procedure in Health Services. METHOD: An experimental, randomized and single-blinded laboratory study was undertaken. The samples were enamelled surfaces, intentionally contaminated with Serratia marcescens microorganisms ATCC 14756 106 CFU/mL with 10% of human saliva added, and were submitted to the procedure of disinfection WITHOUT previous cleaning. The results were compared to disinfection preceded by cleaning. RESULTS: There was a reduction of six logarithms of the initial microbial population, equal in the groups WITH and WITHOUT previous cleaning (p=0.440 and a residual microbial load ≤ 102 CFU. CONCLUSION: The research demonstrated the acceptability of the practice evaluated, bringing an important response to the area of health, in particular to Nursing, which most undertakes procedures of concurrent cleaning /disinfecting of these work surfaces.

  1. Contamination by urban superficial runoff: accumulated heavy metals on a road surface

    Directory of Open Access Journals (Sweden)

    Carlos Alfonso Zafra Mejía

    2007-01-01

    Full Text Available Studying the behaviour of accumulated contamination on urban surfaces is important in designing control methods minimising the impacts of surface runoff on the environment. This paper presents data regarding the sediment collected on the surface of an urban road in the city of Torrelavega in northern Spain during a period of 65 days during which 132 samples were collected. Two types of sediment collection samples were obtained: vacuumed dry samples (free load and those swept up following vacuuming (fixed load. The results showed that heavy metal concentration in the collected sediment (Pb, Zn, Cu and Cd was inversely proportional to particle diameter. High heavy metal concentrations were found in the smaller fraction (63 pm. Regression equations were calculated for heavy metal concentration regarding particle diameter. Large heavy metal loads were found in the larger fraction (125 pm. The results provide information for analysing runoff water quality in urban areas and designing treatment strategies.

  2. Conceptual Models for Migration of Key Groundwater Contaminants Through the Vadose Zone and Into the Upper Unconfined Aquifer Below the B-Complex

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R. Jeffrey; Bjornstad, Bruce N.; Keller, Jason M.; Thorne, Paul D.; Lanigan, David C.; Christensen, J. N.; Thomas, Gregory S.

    2010-07-01

    The B-Complex contains 3 major crib and trench disposal sites and 3 SST farms that have released nearly 346 mega-liters of waste liquids containing the following high groundwater risk drivers: ~14,000 kg of CN, 29,000 kg of Cr, 12,000 kg of U and 145 Ci of Tc-99. After a thorough review of available vadose zone sediment and pore water, groundwater plume, field gamma logging, field electrical resistivity studies, we developed conceptual models for which facilities have been the significant sources of the contaminants in the groundwater and estimated the masses of these contaminants remaining in the vadose zone and currently present in the groundwater in comparison to the totals released. This allowed us to make mass balance calculations on how consistent our knowledge is on the current deep vadose zone and groundwater distribution of contaminants. Strengths and weaknesses of the conceptual models are discussed as well as implications on future groundwater and deep vadose zone remediation alternatives. Our hypothesized conceptual models attribute the source of all of the cyanide and most of the Tc-99 currently in the groundwater to the BY cribs. The source of the uranium is the BX-102 tank overfill event and the source of most of the chromium is the B-7-A&B and B-8 cribs. Our mass balance estimates suggest that there are much larger masses of U, CN, and Tc remaining in the deep vadose zone within ~20 ft of the water table than is currently in the groundwater plumes below the B-Complex. This hypothesis needs to be carefully considered before future remediation efforts are chosen. The masses of these groundwater risk drivers in the the groundwater plumes have been increasing over the last decade and the groundwater plumes are migrating to the northwest towards the Gable Gap. The groundwater flow rate appears to flucuate in response to seasonal changes in hydraulic gradient. The flux of contaminants out of the deep vadose zone from the three proposed sources also

  3. Analysis of body surface radiological contamination for inbound people from Japan to China during the Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Yuan Long; Ma Weidong; Lei Cuiping; Chen Huifang; Li Yuwen; Liu Ying

    2012-01-01

    Objective: To investigate the radiological contamination of body surface for inbound people from Japan to China during Fukushima nuclear accident. Methods: According to The guidance for radiological contamination management for body surface issued by Chinese Center for Disease Control and Prevention, for people evacuated from Japan, the body surface monitoring of radiological contamination was performed by the related agencies in main provinces and cities in China. The monitoring data were collected, analyzed and reported to Ministry of Health. Results: A total of 432 persons were checked. The monitoring results of 429 cases were close to the background level, while those of three persons were higher than the background level. Conclusions: In general,the detected results were as low as the background level. The radiological contamination monitoring of body surface for people from Japan could provide scientific data to relax the horror and panic among them. (authors)

  4. Optical Interferometry with Flexible Coherent Fiber Bundle for Measuring Deposits or Contamination on Surfaces and Inside Tubes

    Data.gov (United States)

    National Aeronautics and Space Administration — A new measuring/cleaning method for closed surfaces (pipes) applicable to removing contaminants (oil films, fungus, rust) from NASA instruments and spacecraft is...

  5. Contact models of repaired articular surfaces: influence of loading conditions and the superficial tangential zone.

    Science.gov (United States)

    Owen, John R; Wayne, Jennifer S

    2011-07-01

    The superficial tangential zone (STZ) plays a significant role in normal articular cartilage's ability to support loads and retain fluids. To date, tissue engineering efforts have not replicated normal STZ function in cartilage repairs. This finite element study examined the STZ's role in normal and repaired articular surfaces under different contact conditions. Contact area and pressure distributions were allowed to change with time, tension-compression nonlinearity modeled collagen behavior in the STZ, and nonlinear geometry was incorporated to accommodate finite deformation. Responses to loading via impermeable and permeable rigid surfaces were compared to loading via normal cartilage, a more physiologic condition, anticipating the two rigid loading surfaces would bracket that of normal. For models loaded by normal cartilage, an STZ placed over the inferior repair region reduced the short-term axial compression of the articular surface by 15%, when compared to a repair without an STZ. Covering the repair with a normal STZ shifted the flow patterns and strain levels back toward that of normal cartilage. Additionally, reductions in von Mises stress (21%) and an increase in fluid pressure (13%) occurred in repair tissue under the STZ. This continues to show that STZ properties of sufficient quality are likely critical for the survival of transplanted constructs in vivo. However, response to loading via normal cartilage did not always fall within ranges predicted by the rigid surfaces. Use of more physiologic contact models is recommended for more accurate investigations into properties critical to the success of repair tissues.

  6. Reduction of microbial contamination on the surfaces of layer houses using slightly acidic electrolyzed water.

    Science.gov (United States)

    Ni, L; Cao, W; Zheng, W C; Zhang, Q; Li, B M

    2015-11-01

    The objective of this study was to evaluate the effectiveness of slightly acidic electrolyzed water (SAEW) in reducing pathogens on pure cultures and on cotton fabric surfaces in the presence of organic matter and estimate its efficacy in comparison with povidone iodine solution for reducing pathogenic microorganisms on internal surfaces of layer houses. Pure cultures of E.coli, S.enteritidis, and S.aureus and cotton fabric surfaces inoculated with these strains were treated with SAEW in the presence of bovine serum albumin (BSA). In the absence of BSA, complete inactivation of all strains in pure cultures and on cotton fabric surfaces was observed after 2.5 and 5 min treatment with SAEW at 40 mg/L of available chlorine concentration (ACC), respectively. The bactericidal efficiency of SAEW increased with increasing ACC, but decreased with increasing BSA concentration. Then, the surfaces of the layer houses were sprayed with SAEW at 60, 80, and 100 mg/L of ACC and povidone iodine using the automated disinfection system at a rate of 110 mL/m(2), respectively. Samples from the floor, wall, feed trough, and egg conveyor belt surfaces were collected with sterile cotton swabs before and after spraying disinfection. Compared to tap water, SAEW and povidone iodine significantly reduced microbial populations on each surface of the layer houses. SAEW with 80 or 100 mg/L of ACC showed significantly higher efficacy than povidone iodine for total aerobic bacteria, staphylococci, coliforms, or yeasts and moulds on the floor and feed trough surfaces (P conveyor belt. Results suggest that SAEW exerts a higher or equivalent bactericidal efficiency for the surfaces compared to povidone iodine, and it may be used as an effective alternative for reducing microbial contamination on surfaces in layer houses. © 2015 Poultry Science Association Inc.

  7. Position-sensitive radiation monitoring (surface contamination monitor). Innovative technology summary report

    International Nuclear Information System (INIS)

    1999-06-01

    The Shonka Research Associates, Inc. Position-Sensitive Radiation Monitor both detects surface radiation and prepares electronic survey map/survey report of surveyed area automatically. The electronically recorded map can be downloaded to a personal computer for review and a map/report can be generated for inclusion in work packages. Switching from beta-gamma detection to alpha detection is relatively simple and entails moving a switch position to alpha and adjusting the voltage level to an alpha detection level. No field calibration is required when switching from beta-gamma to alpha detection. The system can be used for free-release surveys because it meets the federal detection level sensitivity limits requires for surface survey instrumentation. This technology is superior to traditionally-used floor contamination monitor (FCM) and hand-held survey instrumentation because it can precisely register locations of radioactivity and accurately correlate contamination levels to specific locations. Additionally, it can collect and store continuous radiological data in database format, which can be used to produce real-time imagery as well as automated graphics of survey data. Its flexible design can accommodate a variety of detectors. The cost of the innovative technology is 13% to 57% lower than traditional methods. This technology is suited for radiological surveys of flat surfaces at US Department of Energy (DOE) nuclear facility decontamination and decommissioning (D and D) sites or similar public or commercial sites

  8. Microbial methanogenesis in the sulfate-reducing zone of surface sediments traversing the Peruvian margin

    Science.gov (United States)

    Maltby, J.; Sommer, S.; Dale, A. W.; Treude, T.

    2016-01-01

    We studied the concurrence of methanogenesis and sulfate reduction in surface sediments (0-25 cm below sea floor) at six stations (70, 145, 253, 407, 990 and 1024 m) along the Peruvian margin (12° S). This oceanographic region is characterized by high carbon export to the seafloor creating an extensive oxygen minimum zone (OMZ) on the shelf, both factors that could favor surface methanogenesis. Sediments sampled along the depth transect traversed areas of anoxic and oxic conditions in the bottom-near water. Net methane production (batch incubations) and sulfate reduction (35S-sulfate radiotracer incubation) were determined in the upper 0-25 cm b.s.f. of multiple cores from all stations, while deep hydrogenotrophic methanogenesis (> 30 cm b.s.f., 14C-bicarbonate radiotracer incubation) was determined in two gravity cores at selected sites (78 and 407 m). Furthermore, stimulation (methanol addition) and inhibition (molybdate addition) experiments were carried out to investigate the relationship between sulfate reduction and methanogenesis.Highest rates of methanogenesis and sulfate reduction in the surface sediments, integrated over 0-25 cm b.s.f., were observed on the shelf (70-253 m, 0.06-0.1 and 0.5-4.7 mmol m-2 d-1, respectively), while lowest rates were discovered at the deepest site (1024 m, 0.03 and 0.2 mmol m-2 d-1, respectively). The addition of methanol resulted in significantly higher surface methanogenesis activity, suggesting that the process was mostly based on non-competitive substrates - i.e., substrates not used by sulfate reducers. In the deeper sediment horizons, where competition was probably relieved due to the decrease of sulfate, the usage of competitive substrates was confirmed by the detection of hydrogenotrophic activity in the sulfate-depleted zone at the shallow shelf station (70 m).Surface methanogenesis appeared to be correlated to the availability of labile organic matter (C / N ratio) and organic carbon degradation (DIC production

  9. Application of autonomous robotics to surveillance of waste storage containers for radioactive surface contamination

    International Nuclear Information System (INIS)

    Sweeney, F.J.; Beckerman, M.; Butler, P.L.; Jones, J.P.; Reister, D.B.

    1991-01-01

    This paper describes a proof-of-principal demonstration performed with the HERMIES-III mobile robot to automate the inspection of waste storage drums for radioactive surface contamination and thereby reduce the human burden of operating a robot and worker exposure to potentially hazardous environments. Software and hardware for the demonstration were developed by a team consisting of Oak Ridge National Laboratory, and the Universities of Florida, Michigan, Tennessee, and Texas. Robot navigation, machine vision, manipulator control, parallel processing and human-machine interface techniques developed by the team were demonstrated utilizing advanced computer architectures. The demonstration consists of over 100,000 lines of computer code executing on nine computers

  10. Contamination in surface waters around uranium mines in the Guadiana Basin

    Energy Technology Data Exchange (ETDEWEB)

    Bejarano, J.D.; Tome, F.V.; Sanchez, A.M.; Sanchez, A.R.

    1988-01-01

    In a study of the contamination by uranium mines in the River Guadiana basin, we have found the natural higher concentration of uranium in samples collected near the mines and the expected decrease with distance in samples farther away. In spite of this expected result, there is another interesting fact: a natural isotopic separation is observed. Measurements were by alpha spectrometry with a silicon surface barrier detector. The study was completed with total gamma activity at the same sites as for alphas, using an Nal(Tl) detector. (author).

  11. The accuracy of surface-contamination measurements; survey of UK hospitals, 1986

    International Nuclear Information System (INIS)

    Woods, M.J.

    1987-01-01

    In response to a number of concerns expressed at both national and international levels, the National Physical Laboratory (NPL) conducted a survey of UK hospitals and associated Regional Radiation Protection Services. Sources of surface contamination were distributed and participants were requested to measure these and interpret the relevant responses in terms of emission and activity per unit area. The analysis of the returns demonstrates that the vast majority of results was significantly in error and that the quality of radiation protection may be impaired. (author)

  12. Comparison of surface contamination monitors for in vivo measurement of 131I in thyroid

    International Nuclear Information System (INIS)

    Oliveira, S.M.; Dantas, A.L.A.; Dantas, B.M.

    2015-01-01

    The routine handling of radiopharmaceuticals in nuclear medicine represents a significant risk of internal exposure to the staff. The IAEA recommends the implementation of monitoring plans for all workers subject to a risk of exposures above 1 mSv per year. However, in Brazil, such recommendation is practically unfeasible due to the lack of a sufficient number of qualified internal dosimetry services over the country. This work presents an alternative based on a simple and inexpensive methodology aimed to perform in-vivo monitoring of 131 I in thyroid using portable surface contamination probes. All models evaluated showed suitable sensitivity for such application. (author)

  13. Land Surface Temperature Differences within Local Climate Zones, Based on Two Central European Cities

    Directory of Open Access Journals (Sweden)

    Jan Geletič

    2016-09-01

    Full Text Available The main factors influencing the spatiotemporal variability of urban climate are quite widely recognized, including, for example, the thermal properties of materials used for surfaces and buildings, the mass, height and layout of the buildings themselves and patterns of land use. However, the roles played by particular factors vary from city to city with respect to differences in geographical location, overall size, number of inhabitants and more. In urban climatology, the concept of “local climate zones” (LCZs has emerged over the past decade to address this heterogeneity. In this contribution, a new GIS-based method is used for LCZ delimitation in Prague and Brno, the two largest cities in the Czech Republic, while land surface temperatures (LSTs derived from LANDSAT and ASTER satellite data are employed for exploring the extent to which LCZ classes discriminate with respect to LSTs. It has been suggested that correctly-delineated LCZs should demonstrate the features typical of LST variability, and thus, typical surface temperatures should differ significantly among most LCZs. Zones representing heavy industry (LCZ 10, dense low-rise buildings (LCZ 3 and compact mid-rise buildings (LCZ 2 were identified as the warmest in both cities, while bodies of water (LCZ G and densely-forested areas (LCZ A made up the coolest zones. ANOVA and subsequent multiple comparison tests demonstrated that significant temperature differences between the various LCZs prevail. The results of testing were similar for both study areas (89.3% and 91.7% significant LST differences for Brno and Prague, respectively. LSTs computed from LANDSAT differentiated better between LCZs, compared with ASTER. LCZ 8 (large low-rise buildings, LCZ 10 (heavy industry and LCZ D (low plants are well-differentiated zones in terms of their surface temperatures. In contrast, LCZ 2 (compact mid-rise, LCZ 4 (open high-rise and LCZ 9 (sparsely built-up are less distinguishable in both

  14. Sampling for Beryllium Surface Contamination using Wet, Dry and Alcohol Wipe Sampling

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, Kent [Central Missouri State Univ., Warrensburg, MO (United States)

    2004-12-01

    This research project was conducted at the National Nuclear Security Administration's Kansas City Plant, operated by Honeywell Federal Manufacturing and Technologies, in conjunction with the Safety Sciences Department of Central Missouri State University, to compare relative removal efficiencies of three wipe sampling techniques currently used at Department of Energy facilities. Efficiencies of removal of beryllium contamination from typical painted surfaces were tested by wipe sampling with dry Whatman 42 filter paper, with water-moistened (Ghost Wipe) materials, and by methanol-moistened wipes. Test plates were prepared using 100 mm X 15 mm Pyrex Petri dishes with interior surfaces spray painted with a bond coat primer. To achieve uniform deposition over the test plate surface, 10 ml aliquots of solution containing 1 beryllium and 0.1 ml of metal working fluid were transferred to the test plates and subsequently evaporated. Metal working fluid was added to simulate the slight oiliness common on surfaces in metal working shops where fugitive oil mist accumulates over time. Sixteen test plates for each wipe method (dry, water, and methanol) were processed and sampled using a modification of wiping patterns recommended by OSHA Method 125G. Laboratory and statistical analysis showed that methanol-moistened wipe sampling removed significantly more (about twice as much) beryllium/oil-film surface contamination as water-moistened wipes (p< 0.001), which removed significantly more (about twice as much) residue as dry wipes (p <0.001). Evidence for beryllium sensitization via skin exposure argues in favor of wipe sampling with wetting agents that provide enhanced residue removal efficiency.

  15. A model to determine the radiological implications of non-fixed radioactive contamination on the surfaces of packages and conveyances

    International Nuclear Information System (INIS)

    Hughes, J.S.; Warner Jones, S.M.; Lizot, M.T.; Perrin, M.L.; Thierfeld, S.; Schroedl, E.; Schwarz, G.; Rawl, R.; Munakata, M.; Hirose, M.

    2004-01-01

    The surfaces of packages and conveyances used to transport radioactive materials can sometimes become contaminated with radioactive material. This usually occurs as a result of the transfer of radioactive material from areas in which these packages and conveyances are handled. This contamination may subsequently be transferred to transport equipment, workers and to areas accessible to the public. This can represent a significant radiation safety issue that requires careful management. The current regulatory limits for non-fixed contamination on packages and conveyances have been in use for over 40 years, and are based on a simple exposure model. However, the bases on which these limits were derived have been subject to changes, as a result of successive revisions of international recommendations. In recognition of this need for a review and analysis of the current contamination limits an IAEA Co-ordinated Research Project (CRP) on the ''Radiological Aspects of Package and Conveyance Non-Fixed Contamination'' was initiated to review the scientific basis for the current regulatory limits for surface contamination. The CRP was also to develop guidance material for evaluating the radiological significance of surface contamination to workers and the public in light of state-of-the-art research, technical developments and current transport practices. The specific objectives of the work undertaken within this multi-national CRP were, in accordance with the terms of reference: To ensure that appropriate models exist for all package types including consideration of the aspects pertinent for assessing and revising a surface contamination model for transport. To collect - where possible - contamination, operational and dosimetric data to ensure modelling consistency. To use models for assessing the limitations and optimisation of radiation doses incurred in transport operations, and to consider preventive methods for package and conveyance contamination

  16. A Review of Removable Surface Contamination on Radioactive Materials Transportation Containers

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Jr, W. E.; Watson, E. C.; Murphy, D. W.; Harrer, B. J.; Harty, R.; Aldrich, J. M.

    1981-05-01

    This report contains the results of a study sponsored by the U.S. Nuclear Regulatory Commission (NRC) of removable surface contamination on radioactive materials transportation containers. The purpose of the study is to provide information to the NRC during their review of existing regulations. Data was obtained from both industry and literature on three major topics: 1) radiation doses, 2) economic costs, and 3) contamination frequencies. Containers for four categories of radioactive materials are considered including radiopharmaceuticals, industrial sources, nuclear fuel cycle materials, and low-level radioactive waste. Assumptions made in this study use current information to obtain realistic yet conservative estimates of radiation dose and economic costs. Collective and individual radiation doses are presented for each container category on a per container basis. Total doses, to workers and the public, are also presented for spent fuel cask and low-level waste drum decontamination. Estimates of the additional economic costs incurred by lowering current limits by factors of 10 and 100 are presented. Current contamination levels for each category of container are estimated from the data collected. The information contained in this report is designed to be useful to the NRC in preparing their recommendations for new regulations.

  17. Nickel, Lead and Zinc Contamination in the Surface Sediments of Agh Gel Wetland, Iran

    Directory of Open Access Journals (Sweden)

    Soheil Sobhan Ardakani

    2016-07-01

    Full Text Available Background & Aims of the Study: Due to the increased human activities around the Agh Gel wetland, this study aimed to measured accumulations of heavy metals (Ni, Pb and Zn in the surface sediment samples taken from this wetland. Materials & Methods: Samples were taken from 10 stations and exposed to bulk digestion and chemical partitioning. Finally, Ni, Pb and Zn concentrations were monitored with ICP-OES in the sediments. Also, geo-accumulation index, contamination factor and pollution load index were used to evaluate the magnitude of contaminants in the sediment profile. Results: The results showed, the average of metal concentration in samples (mg kg-1 wet weight were 34.20±3.58 for Ni, 25.37±2.52 for Pb and 127.20±15.21 for Zn, respectively. Therefore, the pattern of metal concentrations in sediment was determined as Zinc>Nickel >Lead. According to the mean I-geo values, sediments' qualities are classified as unpolluted category for Ni and Pb. Also, sediment's quality is classified as unpolluted to moderately polluted for Zn. The CF values for all elements are classified as moderate contamination. The PLI values indicated that metal pollution exists for all sampling stations. Conclusions: The obtained results indicated that the Agh Gel wetland has a potential to threaten by chemical pollutants such as agricultural effluent. So, in order to preserve the environment of the Agh Gel wetland from deterioration, monitoring of water and sediment qualities is recommended periodically.

  18. Assessment of the SMAP Level-4 Surface and Root-Zone Soil Moisture Product Using In Situ Measurements

    NARCIS (Netherlands)

    Reichle, Rolf H.; De Lannoy, Gabrielle J. M.; Liu, Qing; Ardizzone, Joseph V.; Colliander, Andreas; Conaty, Austin; Crow, Wade; Jackson, Thomas J.; Jones, Lucas A.; Kimball, John S.; Koster, Randal D.; Mahanama, Sarith P.; Smith, Edmond B.; Berg, Aaron; Bircher, Simone; Bosch, David; Caldwell, Todd G.; Cosh, Michael; Holifield Collins, Chandra D.; Jensen, Karsten H.; Livingston, Stan; Lopez-baeza, Ernesto; Martínez-fernández, José; Mcnairn, Heather; Moghaddam, Mahta; Pacheco, Anna; Pellarin, Thierry; Prueger, John; Rowlandson, Tracy; Seyfried, Mark; Starks, Patrick; Su, Bob; Thibeault, Marc; Van Der Velde, Rogier; Walker, Jeffrey; Wu, Xiaoling; Zeng, Yijian

    2017-01-01

    The Soil Moisture Active Passive (SMAP) mission Level-4 Surface and Root-Zone Soil Moisture (L4_SM) data product is generated by assimilating SMAP L-band brightness temperature observations into the NASA Catchment land surface model. The L4_SM product is available from 31 March 2015 to present

  19. Thallium dispersal and contamination in surface sediments from South China and its source identification.

    Science.gov (United States)

    Liu, Juan; Wang, Jin; Chen, Yongheng; Shen, Chuan-Chou; Jiang, Xiuyang; Xie, Xiaofan; Chen, Diyun; Lippold, Holger; Wang, Chunlin

    2016-06-01

    Thallium (Tl) is a non-essential element in humans and it is considered to be highly toxic. In this study, the contents, sources, and dispersal of Tl were investigated in surface sediments from a riverine system (the western Pearl River Basin, China), whose catchment has been contaminated by mining and roasting of Tl-bearing pyrite ores. The isotopic composition of Pb and total contents of Tl and other relevant metals (Pb, Zn, Cd, Co, and Ni) were measured in the pyrite ores, mining and roasting wastes, and the river sediments. Widespread contamination of Tl was observed in the sediments across the river, with the highest concentration of Tl (17.3 mg/kg) measured 4 km downstream from the pyrite industrial site. Application of a modified Institute for Reference Materials and Measurement (IRMM) sequential extraction scheme in representative sediments unveiled that 60-90% of Tl and Pb were present in the residual fraction of the sediments. The sediments contained generally lower (206)Pb/(207)Pb and higher (208)Pb/(206)Pb ratios compared with the natural Pb isotope signature (1.2008 and 2.0766 for (206)Pb/(207)Pb and (208)Pb/(206)Pb, respectively). These results suggested that a significant fraction of non-indigenous Pb could be attributed to the mining and roasting activities of pyrite ores, with low (206)Pb/(207)Pb (1.1539) and high (208)Pb/(206)Pb (2.1263). Results also showed that approximately 6-88% of Tl contamination in the sediments originated from the pyrite mining and roasting activities. This study highlights that Pb isotopic compositions could be used for quantitatively fingerprinting the sources of Tl contamination in sediments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. The effect of surface anisotropy in the slippery zone of Nepenthes alata pitchers on beetle attachment.

    Science.gov (United States)

    Gorb, Elena V; Gorb, Stanislav N

    2011-01-01

    The slippery zone in pitchers of the carnivorous plant Nepenthes alata bears scattered prominent lunate cells and displays continuous epicuticular crystalline wax coverage. The aim of this study was to examine the influence of the surface anisotropy, caused by the shape of lunate cells, on insect attachment ability. Traction tests with ladybird beetles Coccinella septempunctata were performed in two types of experiments, where surface samples of (1) intact pitchers, (2) chemically de-waxed pitchers, and (3) their polymer replicas were placed horizontally. Beetle traction forces were measured when they walked on test surfaces in either an upward (towards the peristome) or downward (towards the pitcher bottom) direction, corresponding to the upright or inverted positions of the pitcher. On intact pitcher surfaces covered with both lunate cells and wax crystals, experiments showed significantly higher forces in the direction towards the pitcher bottom. To distinguish between the contributions, from claw interlocking and pad adhesion, to insect attachment on the pitcher surfaces, intact versus claw-ablated beetles were used in the second type of experiment. On both de-waxed plant samples and their replicas, intact insects generated much higher forces in the downward direction compared to the upward one, whereas clawless insects did not. These results led to the conclusion that, (i) due to the particular shape of lunate cells, the pitcher surface has anisotropic properties in terms of insect attachment, and (ii) claws were mainly responsible for attachment enhancement in the downward pitcher direction, since, in this direction, they could interlock with overhanging edges of lunate cells.

  1. The effect of surface anisotropy in the slippery zone of Nepenthes alata pitchers on beetle attachment

    Directory of Open Access Journals (Sweden)

    Elena V. Gorb

    2011-06-01

    Full Text Available The slippery zone in pitchers of the carnivorous plant Nepenthes alata bears scattered prominent lunate cells and displays continuous epicuticular crystalline wax coverage. The aim of this study was to examine the influence of the surface anisotropy, caused by the shape of lunate cells, on insect attachment ability. Traction tests with ladybird beetles Coccinella septempunctata were performed in two types of experiments, where surface samples of (1 intact pitchers, (2 chemically de-waxed pitchers, and (3 their polymer replicas were placed horizontally. Beetle traction forces were measured when they walked on test surfaces in either an upward (towards the peristome or downward (towards the pitcher bottom direction, corresponding to the upright or inverted positions of the pitcher. On intact pitcher surfaces covered with both lunate cells and wax crystals, experiments showed significantly higher forces in the direction towards the pitcher bottom. To distinguish between the contributions, from claw interlocking and pad adhesion, to insect attachment on the pitcher surfaces, intact versus claw-ablated beetles were used in the second type of experiment. On both de-waxed plant samples and their replicas, intact insects generated much higher forces in the downward direction compared to the upward one, whereas clawless insects did not. These results led to the conclusion that, (i due to the particular shape of lunate cells, the pitcher surface has anisotropic properties in terms of insect attachment, and (ii claws were mainly responsible for attachment enhancement in the downward pitcher direction, since, in this direction, they could interlock with overhanging edges of lunate cells.

  2. Fate factors and emission flux estimates for emerging contaminants in surface waters

    Directory of Open Access Journals (Sweden)

    Hoa T. Trinh

    2016-01-01

    Full Text Available Pharmaceuticals, personal care products, hormones, and wastewater products are emerging environmental concerns for manifold reasons, including the potential of some compounds found in these products for endocrine disruption at a very low chronic exposure level. The environmental occurrences and sources of these contaminants in the water, soil, sediment and biota in European nations and the United States are well documented. This work reports a screening-level emission and fate assessment of thirty compounds, listed in the National Reconnaissance of the United States Geological Survey (USGS, 1999–2000 as the most frequently detected organic wastewater contaminants in U.S. streams and rivers. Estimations of the surface water fate factors were based on Level II and Level III multimedia fugacity models for a 1000 km2 model environment, the size of a typical county in the eastern United States. The compounds are categorized into three groups based upon the sensitivity of their predicted surface water fate factors to uncertainties in their physicochemical property values and the landscape parameters. The environmental fate factors, mass distributions, and loss pathways of all of the compounds are strongly affected by their assumed modes of entry into the environment. It is observed that for thirteen of the thirty organic wastewater contaminants most commonly detected in surface waters, conventional treatment strategies may be ineffective for their removal from wastewater effluents. The surface water fate factors predicted by the fugacity models were used in conjunction with the surface water concentrations measured in the USGS reconnaissance to obtain emission flux estimates for the compounds into U.S. streams and rivers. These include estimated fluxes of 6.8 × 10−5 to 0.30 kg/h km2 for the biomarker coprostanol; 1.7 × 10−5 to 6.5 × 10−5 kg/h km2 for the insect repellent N,N-diethyltoluamide; and 4.3 × 10−6 to 3.1 × 10−5 kg/h km2 for

  3. [Cleaning efficacy of different solvents on sealer-contaminated dentin surface].

    Science.gov (United States)

    Zang, H L; Wang, Y; Liang, Y H

    2018-02-18

    To evaluate the influence of an epoxy resin-based sealer on the bond strength of adhesive resins to dentin and the cleaning efficacy of different solvents in removing sealer residues. The occlusal enamel of 25 freshly extracted human third molars without caries were removed to expose flat surfaces of dentin. The teeth were randomly divided into five groups according to the treatment received: For negative control group, the dentin surfaces were not contaminated with AH-Plus; For the other 4 experimental groups, the samples were contaminated with AH-Plus for 5 min and different measures were taken: For positive control group, the sealer were wiped with dry cotton pellets; For solvents experimental groups: cotton pellets saturated with 95% (volume fraction) ethanol, 99.5% (volume fraction) acetone or 99% (volume fraction) amyl acetate were used to wipe the sealer until the surface appeared clean when viewed through a stereomicroscope under ×10 magnification, then rinsed with de-ionized water for 3 s. After sealer removal, a self-etching adhesive system was applied on the surfaces with resin composite. The samples were sectioned into 1.0 mm×1.0 mm stick specimens (n=45) for microtensile test. Failure modes at the dentin-resin interface were observed using a stereomicroscope. The samples were sectioned into 1.0 mm piece specimens (n=4) for scanning electron microscope observation. The microtensile bond strength data were analyzed by one-way ANOVA. Chi-square test were used to analyse the failure modes between the groups. There was significant difference among the five groups (Pamyl acetate group and negative control group (P>0.05). The bond strength of acetone group and amyl acetate group were (45.94±10.37) MPa and (43.99±7.01) MPa, respectively. The ethanol group exhibited lower bond strength than that of acetone group and amyl acetate group (Pamyl acetate group were as dense and uniform as in negative control group. The distribution of failure modes showed no

  4. HTO transfer from contaminated surfaces to the atmosphere: a database for model validation

    International Nuclear Information System (INIS)

    Davis, P.A.; Amiro, B.D.; Workman, W.J.G.; Corbett, B.J.

    1996-12-01

    This report comprises a detailed database that can be used to validate models of the emission of tritiated water vapour (HTO) from natural contaminated surfaces to the atmosphere. The data were collected in 1992 July during an intensive field study based on the flux-gradient method of micrometeorology. The measurements were made over a wetland area at the Chalk River Laboratories, and over a grassed field near the Pickering Nuclear Generating Station. The study sites, the sampling protocols and the analytical techniques are described in detail, and the measured fluxes are presented. The report also contains a detailed listing of HTO concentrations in air at two heights, HTO concentrations in the source compartments (soil, surface water and vegetation), supporting meteorological data, and various vegetation and soil properties. The uncertainties in all of the measured data are estimated. (author). 15 refs., 23 tabs., 9 figs

  5. Agricultural contamination in soil-groundwater-surface water systems in the North China Plain

    DEFF Research Database (Denmark)

    Brauns, Bentje

    of China’s main agricultural production zones, accounting for about one third of the national grain output. The dominant crop system is a winter wheat and summer maize rotation. Beginning in the 1980s, in an effort to increase agricultural productivity, China’s government heavily promoted the use....... Additionally, nitrate was infiltrating from the surface of the field into the aquifer. Anammox, denitrification, and cation exchange were the suggested dominant removal processes in the soil-surface water-groundwater system examined in this study, which showed a very high nitrogen removal capacity. However......, if the composition of the river water were to change (if, for instance, the ammonium concentration were to decrease) the removal processes in the system would also be altered. Consequently, further monitoring of nitrate pollution is suggested. Regarding pesticides, a literature review and data assessment revealed...

  6. Measurements of the spatial distribution of tritium in air above a chronically contaminated surface

    International Nuclear Information System (INIS)

    Workman, W.J.G.; Davis, P.A.; Wood, M.J.; Barry, P.J.

    1993-01-01

    Tritium in air (HTO) concentrations were measured over a 13 month period above a surface that is chronically contaminated by tritium-bearing groundwater from a waste management area. The measurements were made using passive diffusion samplers, which were sited at six locations (about 100 m apart) at 0.15, 0.9, and 1.8 m above ground level. The diffusion samplers were compact, sampled at a known rate, and required no external power source. They are ideal for remote locations and require a minimum of effort to collect and analyze the data. HTO-in-air concentration peaked in the summer at 500-1500 Bq.m -3 and decreased in the winter to 1-120 Bq.m -3 . In general, concentration decreased with height above ground level, implying that HTO is being lost from the surface to the atmosphere. The flux of tritium to the atmosphere must, therefore, be taken into account to estimate the tritium mass balance for a contaminated area. (Author) 3 figs., 5 tabs., 10 refs

  7. User's Guide: Database of literature pertaining to the unsaturated zone and surface water-ground water interactions at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Hall, L.F.

    1993-05-01

    Since its beginnings in 1949, hydrogeologic investigations at the Idaho National Engineering Laboratory (INEL) have resulted in an extensive collection of technical publications providing information concerning ground water hydraulics and contaminant transport within the unsaturated zone. Funding has been provided by the Department of Energy through the Department of Energy Idaho Field Office in a grant to compile an INEL-wide summary of unsaturated zone studies based on a literature search. University of Idaho researchers are conducting a review of technical documents produced at or pertaining to the INEL, which present or discuss processes in the unsaturated zone and surface water-ground water interactions. Results of this review are being compiled as an electronic database. Fields are available in this database for document title and associated identification number, author, source, abstract, and summary of information (including types of data and parameters). AskSam reg-sign, a text-based database system, was chosen. WordPerfect 5.1 copyright is being used as a text-editor to input data records into askSam

  8. A comparison of the surface contaminants of handwritten recycled and printed electronic parenteral nutrition prescriptions and their transfer to bag surfaces during delivery to hospital wards.

    Science.gov (United States)

    Austin, Peter David; Hand, Kieran Sean; Elia, Marinos

    2014-02-01

    Handwritten recycled paper prescription for parenteral nutrition (PN) may become a concentrated source of viable contaminants, including pathogens. This study examined the effect of using fresh printouts of electronic prescriptions on these contaminants. Cellulose sponge stick swabs with neutralizing buffer were used to sample the surfaces of PN prescriptions (n = 32 handwritten recycled; n = 32 printed electronic) on arrival to the pharmacy or following printing and PN prescriptions and bags packaged together during delivery (n = 38 handwritten recycled; n = 34 printed electronic) on arrival to hospital wards. Different media plates and standard microbiological procedures identified the type and number of contaminants. Staphylococcus aureus, fungi, and mold were infrequent contaminants. nonspecific aerobes more frequently contaminated handwritten recycled than printed electronic prescriptions (into pharmacy, 94% vs 44%, fisher exact test P .001; onto wards, 76% vs 50%, p = .028), with greater numbers of colony-forming units (CFU) (into pharmacy, median 130 [interquartile range (IQR), 65260] VS 0 [075], Mann-Whitney U test, P .001; onto wards, median 120 [15320] vs 10 [040], P = .001). packaging with handwritten recycled prescriptions led to more frequent nonspecific aerobic bag surface contamination (63% vs 41%, fisher exact test P = .097), with greater numbers of CFU (median 40 [IQR, 080] VS 0 [040], Mann-Whitney U test, P = .036). The use of printed electronic PN prescriptions can reduce microbial loads for contamination of surfaces that compromises aseptic techniques.

  9. Land Surface Temperature Differences within Local Climate Zones, Based on Two Central European Cities

    Czech Academy of Sciences Publication Activity Database

    Geletič, Jan; Lehnert, M.; Dobrovolný, Petr

    2016-01-01

    Roč. 8, č. 10 (2016), č. článku 788. ISSN 2072-4292 R&D Projects: GA MŠk(CZ) LO1415 Grant - others:UrbanAdapt(XE) EHP-CZ02-OV-1-036-2015 Program:CZ02 Biodiverzita a ekosystémové služby / Monitorování a integrované plánování a kontrola v životním prostředí/ Adaptace na změnu klimatu Institutional support: RVO:67179843 Keywords : land surface temperature * local climate zones * ASTER * LANDSAT * analysis of variance * Prague * Brno * Czech Republic Subject RIV: EH - Ecology, Behaviour Impact factor: 3.244, year: 2016

  10. Determination of platinum surface contamination in veterinary and human oncology centres using inductively coupled plasma mass spectrometry

    NARCIS (Netherlands)

    Janssens, T.; Brouwers, E. E M; de Vos, J. P.; de Vries, N.; Schellens, J. H M; Beijnen, J. H.

    2015-01-01

    The objective of this study was to determine the surface contamination with platinum-containing antineoplastic drugs in veterinary and human oncology centres. Inductively coupled plasma mass spectrometry was used to measure platinum levels in surface samples. In veterinary and human oncology

  11. Solutal Marangoni flows of miscible liquids drive transport without surface contamination

    Science.gov (United States)

    Kim, Hyoungsoo; Muller, Koen; Shardt, Orest; Afkhami, Shahriar; Stone, Howard A.

    2017-11-01

    Mixing and spreading of different liquids are omnipresent in nature, life and technology, such as oil pollution on the sea, estuaries, food processing, cosmetic and beverage industries, lab-on-a-chip devices, and polymer processing. However, the mixing and spreading mechanisms for miscible liquids remain poorly characterized. Here, we show that a fully soluble liquid drop deposited on a liquid surface remains as a static lens without immediately spreading and mixing, and simultaneously a Marangoni-driven convective flow is generated, which are counterintuitive results when two liquids have different surface tensions. To understand the dynamics, we develop a theoretical model to predict the finite spreading time and length scales, the Marangoni-driven convection flow speed, and the finite timescale to establish the quasi-steady state for the Marangoni flow. The fundamental understanding of this solutal Marangoni flow may enable driving bulk flows and constructing an effective drug delivery and surface cleaning approach without causing surface contamination by immiscible chemical species.

  12. Inactivation of internalized and surface contaminated enteric viruses in green onions.

    Science.gov (United States)

    Hirneisen, Kirsten A; Kniel, Kalmia E

    2013-09-02

    With increasing outbreaks of gastroenteritis associated with produce, it is important to assess interventions to reduce the risk of illness. UV, ozone and high pressure are non-thermal processing technologies that have potential to inactivate human pathogens on produce and allow the retention of fresh-like organoleptic properties. The objective of this study was to determine if UV, ozone, and high pressure are effective technologies compared to traditional chlorine spray on green onions to reduce enteric viral pathogens and to determine the effect of location of the virus (surface or internalized) on the efficacy of these processes. Mature green onion plants were inoculated with murine norovirus (MNV), hepatitis A virus (HAV) and human adenovirus type 41 (Ad41) either on the surface through spot inoculation or through inoculating contaminated hydroponic solution allowing for uptake of the virus into the internal tissues. Inoculated green onions were treated with UV (240 mJ s/cm(2)), ozone (6.25 ppm for 10 min), pressure (500 MPa, for 5 min at 20°C), or sprayed with calcium hypochlorite (150 ppm, 4°C). Viral inactivation was determined by comparing treated and untreated inoculated plants using cell culture infectivity assays. Processing treatments were observed to greatly affect viral inactivation. Viral inactivation for all three viruses was greatest after pressure treatment and the lowest inactivation was observed after chlorine and UV treatment. Both surface inoculated viruses and viruses internalized in green onions were inactivated to some extent by these post-harvest processing treatments. These results suggest that ozone and high pressure processes aimed to reduce the level of microbial contamination of produce have the ability to inactivate viruses if they become localized in the interior portions of produce. © 2013.

  13. Beta Autoradiography. An analytical technique to investigate radionuclides contamination on surface

    International Nuclear Information System (INIS)

    Ficher, P.; Goutelard, F.; Siitari-Kauppi, M.

    2012-01-01

    In decommissioning of old buildings and after disposal of nuclear facilities (materials, glove boxes,...), the inventory of the radioactive contamination of various building materials needs to be obtained in order to fix the working condition for dismantling. The challenge of this study was to classify different building materials of a whole research laboratory that was dedicated to research on organic molecules labeled with H-3 and C-14. The problem of waste classification is essential for safety treatment of waste and also for its cost. The analytical technique of beta autoradiography particularly well known for biological researches has been tested to investigate radionuclides contamination on surface. This technique is mainly interesting for beta and alpha emitters but also sensitive to gamma radiation. The first step of this technique is the deposit of a film on the surface of material to be analyzed. Films can be deposited on the ground or also fixed on the walls or even on the ceiling. The film is a plastic sheet covered with an emulsion containing photostimulable crystals and Eu that is activated when the film is exposed on radioactive source. The exposed films are then scanned with the Cyclone Plus equipment to get a digitized image. This image represents the radioactivity of the surface studied. The possibility to re-use the films is very important to investigate a large area. This autoradiography technique has retained our attention for its sensitivity and moreover the possibility of 2-dimensional investigation has been found as a real advantage. However it remains now as a qualitative technique and new studies must be launched to prove its quantitative potentialities. The high spatial resolution was not as important as in biological observation, and the mm resolution is totally sufficient

  14. Monitoring of selected priority and emerging contaminants in the Guadalquivir River and other related surface waters in the province of Jaén, South East Spain.

    Science.gov (United States)

    Robles-Molina, José; Gilbert-López, Bienvenida; García-Reyes, Juan F; Molina-Díaz, Antonio

    2014-05-01

    The province of Jaén counts with four natural parks, numerous rivers, reservoirs and wetlands; moreover, it is probably the region with higher olive oil production in the world, which makes this zone a proper target to be studied based on the European Water Framework Directive 2000/60/CE. The aim of this survey is to monitor a total number of 373 compounds belonging to different families (pesticides, PAHs, nitrosamines, drugs of abuse, pharmaceuticals and life-style compounds) in surface waters located at different points of the province of Jaén. Among these compounds some priority organic substances (regulated by the EU Directive 2008/105/EC) and pollutants of emerging concern (not regulated yet) can be found. A liquid chromatography electrospray time-of-flight mass spectrometry (LC-TOFMS) method covering 340 compounds was developed and applied, together with a gas chromatography triple-quadrupole mass spectrometry (GC-MS/MS) method which enabled the analysis of 63 organic contaminants (30 of these compounds are analyzed by LC-TOFMS as well). From April 2009 to November 2010 a total of 83 surface water samples were collected (rivers, reservoirs and wetlands). In this period numerous organic contaminants were detected, most of them at the ng L(-1) level. The most frequently priority substances found were chlorpyrifos ethyl, diuron and hexachlorobenzene. Within the other groups, the most frequently detected compounds were: terbuthylazine, oxyfluorfen, desethyl terbuthylazine, diphenylamine (pesticide family); fluorene, phenanthrene, pyrene (PAHs group), codeine, paracetamol (pharmaceuticals compounds) and caffeine, nicotine (life-style compounds). As is could be expected, the total concentration of emerging contaminants is distinctly larger than that of priority pollutants, highlighting the importance of continuing with the study of their presence, fate and effects in aquatic environments. However, concentration levels (at the ng per liter level) are low in

  15. Sorption of heavy metals and radionuclides on mineral surfaces in the presence of organic co-contaminants. 1997 annual progress report

    International Nuclear Information System (INIS)

    Leckie, J.; Redden, G.

    1997-01-01

    'This project fits well within the overall objectives established by the Environmental Management and Science Program to promote long-term basic research that will provide the tools for more effective and lower cost remediation efforts at DOE sites where hazardous and radioactive wastes or contamination zones are present. In order to develop the necessary remediation technology it has been recognized that a fundamental understanding of the various chemical and physical factors associated with waste treatment and contaminant transport must be established. Some of the specific topics include waste pretreatment, volume reduction, immobilization, separation methods, the interactions of actinides and heavy metals with surfaces in the presence of organic residues and co-contaminants, contaminant transport in the environment, and long-term storage site assessment. This project has direct and potential application in all these areas. The interaction and partitioning of contaminant metals and radionuclides between solution and solid- surface phases is a fundamental issue for waste treatment and predicting contaminant transport in the environment. Many factors are involved in the functional relationships describing chemical reactivity and physical distribution of chemical species. These include modification of chemical behavior by the suite of chemical co-contaminants in a system. Organic complexing agents are common components of waste mixtures and include both synthetic components specifically introduced as part of processing methods, and poorly characterized compounds that were introduced separately or evolved within the highly reactive wastes. Natural organic complexing agents such as citric acid and siderophores are common in nature and represent factors that will further influence contaminant transport in soils and aquatic systems. Knowledge of the existence of a metal-organic complex cannot automatically be used to predict changes in solid-solution partitioning of the

  16. Near-surface seismic surveys at Rifle, Colorado for shallow groundwater contamination risk assessment

    Science.gov (United States)

    Chen, J.; Zelt, C. A.; Levander, A.

    2013-12-01

    In August 2012, we carried out a series of seismic surveys at a site located approximately 0.3 mile east of the city of Rifle in Garfield County, Colorado. The ground water beneath this site was contaminated by former vanadium and uranium ore-processing operations from 1924 through 1958. The site is on an alluvial terrace created by a flood-plain meander of the Colorado River. On the south side, the terrace is bounded by a steep descending slope to the Colorado River; on the other sides, it is bounded by ascending slopes of the more resistant sedimentary rocks of the Wasatch Formation. Although remedial actions have been taken to remove the contaminated surface materials, there are still potential risks from residual materials and redistribution of the contaminated water harming human health. This seismic project, funded by The U.S. Department of Energy, was designed to provide hydrogeologic information through sub-surface velocity model building and imaging of the water aquifer. A 3D compressional wave seismic survey covers an area that is 96 m in the N-S direction by 60 m in the E-W direction. An orthogonal, symmetric receiver and source template was used with 24 receiver lines, 96 channels per receiver line, and 2.5 m between lines. The inline shot and receiver spacing is 2 m and 1 m, respectively. The source was an accelerated weight drop striking a metal plate. The source has a dominant frequency at ~60 Hz, and is down by 20 db at 20 Hz and 150 Hz, providing data suitable for seismic tomography and seismic migration methods. Besides this 3D survey, three other seismic experiments were performed: (1) a 2D multi-component source and receiver survey, (2) a 3D surface wave experiment using 4.5 Hz geophones, and (3) an ambient noise experiment using 4.5 Hz geophones to record passing vehicles and trains. Preliminary results of the data analysis will be presented.

  17. Elastic Wavespeed Images of Northern Chile Subduction Zone from the Joint Inversion of Body and Surface Waves: Structure of the Andean Forearc and the Double Seismic Zone

    Science.gov (United States)

    Comte, D.; Carrizo, D.; Roecker, S. W.; Peyrat, S.; Arriaza, R.; Chi, R. K.; Baeza, S.

    2015-12-01

    Partly in anticipation of an imminent megathrust earthquake, a significant amount of seismic data has been collected over the past several years in northern Chile by local deployments of seismometers. In this study we generate elastic wavespeed images of the crust and upper mantle using a combination of body wave arrival times and surface wave dispersion curves. The body wave data set consists of 130000 P and 108000 S wave arrival times generated by 12000 earthquakes recorded locally over a period of 25 years by networks comprising about 360 stations. The surface wave data set consists of Rayleigh wave dispersion curves determined from ambient noise recorded by 60 broad band stations from three different networks over a period of three years. Transit time biases due to an uneven distribution of noise were estimated using a technique based on that of Yao and van der Hilst (2009) and found to be as high as 5% for some station pairs. We jointly invert the body and surface wave observations to both improve the overall resolution of the crustal images and reduce the trade-off between shallow and deep structures in the images of the subducted slab. Of particular interest in these images are three regions of anomalous Vp/Vs: (1) An extensive zone of low Vp/Vs (1.68) correlates with trench-parallel magmatic belts emplaced in the upper continental crust. In the region of the coast and continental slope, low Vp/Vs corresponds to batholithic structures in the Jurassic-Cretaceous magmatic arc. Between the central depression and Domeyko Cordillera, low Vp/Vs correlates with the distribution of magmatic arcs of Paleocene-Oligocene and Eocene-Oligocene age. Low Vp/Vs also correlates with the location of the Mejillones Peninsula. (2) A region of high Vp/Vs occurs in what is most likely the serpentinized wedge of the subduction zone. (3) An additional zone of low Vp/Vs is located in the middle of the double seismic zone at depths of 90-110 km. This region may exist all along the

  18. Hydrocarbons in surface sediments from the Sfax coastal zone, (Tunisia) Mediterranean Sea.

    Science.gov (United States)

    Zaghden, Hatem; Kallel, Monem; Louati, Afifa; Elleuch, Boubaker; Oudot, Jean; Saliot, Alain

    2005-11-01

    The Semi-enclosed Mediterranean Sea records various signals of high anthropic pressures from surrounding countries and the industrialized European countries. This is particularly true for oil pollution. Although accounting for 1% of the world's ocean surface, it receives about 25% of the petroleum inputs to the ocean. To achieve a global budget we need to collect information from different parts of the Mediterranean. Particularly, we focus in this paper on the Southern Mediterranean, where data are presently very scarce. In this context, the University of Sfax has undertaken an estimation of hydrocarbon pollution along the coasts of Sfax and Gabès Gulf. Non-aromatic hydrocarbons were analysed in 8 surface sediments by FT/IR and GC/MS. Non-aromatic hydrocarbon concentrations vary in the range 310-1406 microg g(-1) sediments dry weight, which is high, compared to other Mediterranean sites. GC/MS data indicate a large group of unresolved compounds suggesting a petroleum contamination, confirmed by the identification of hopanes with predominant C29 and C30alpha,beta compounds and steranes with predominance of C27 over C28) and C29 compounds.

  19. Analysis of surface roughness and surface heat affected zone of steel S355J0 after plasma arc cutting

    International Nuclear Information System (INIS)

    Hatala, Michal; Chep, Robert; Pandilov, Zoran

    2010-01-01

    This paper deals with thermal cutting technology of materials with plasma arc. In the first part of this paper the theoretical knowledge of the principles of plasma arc cutting and current use of this technology in industry are presented. The cut of products with this technology is perpendicular and accurate, but the use of this technology affects micro-structural changes and depth of the heat affected zone (HAZ). This article deals with the experimental evaluation of plasma arc cutting technological process. The influence of technological factors on the roughness parameter Ra of the steel surface EN S355J0 has been evaluated by using planned experiments. By using the factor experiment, the significance of the four process factors such as plasma burner feed speed, plasma gas pressure, nozzle diameter, distance between nozzle mouth and material has been analyzed. Regression models obtained by multiple linear regression indicate the quality level of observed factors function. The heat from plasma arc cutting affects the micro-structural changes of the material, too.

  20. Radioactive contamination monitor

    International Nuclear Information System (INIS)

    Hasegawa, Toru; Hashimoto, Tadao; Hashimoto, Manabu

    2007-01-01

    In order to prevent radioactive materials from spreading contamination from nuclear power plants outside the radiation control area, the surface contamination of all material transferred outside from the control area is monitored. This paper presents an overview and describes features of: (1) personnel surface contamination monitoring assemblies for measuring the surface contamination on workers, (2) article surface contamination monitoring assemblies for measuring the surface contamination on articles, (3) laundry monitors for measuring the surface contamination on worker clothes worn inside the control area, and (4) hand-foot-clothing contamination monitors for measuring the surface contamination on hands, feet and clothing. (author)

  1. Urban Imperviousness Effects on Summer Surface Temperatures Nearby Residential Buildings in Different Urban Zones of Parma

    Directory of Open Access Journals (Sweden)

    Marco Morabito

    2017-12-01

    Full Text Available Rapid and unplanned urban growth is responsible for the continuous conversion of green or generally natural spaces into artificial surfaces. The high degree of imperviousness modifies the urban microclimate and no studies have quantified its influence on the surface temperature (ST nearby residential building. This topic represents the aim of this study carried out during summer in different urban zones (densely urbanized or park/rural areas of Parma (Northern Italy. Daytime and nighttime ASTER images, the local urban cartography and the Italian imperviousness databases were used. A reproducible/replicable framework was implemented named “Building Thermal Functional Area” (BTFA useful to lead building-proxy thermal analyses by using remote sensing data. For each residential building (n = 8898, the BTFA was assessed and the correspondent ASTER-LST value (ST_BTFA and the imperviousness density were calculated. Both daytime and nighttime ST_BTFA significantly (p < 0.001 increased when high levels of imperviousness density surrounded the residential buildings. These relationships were mostly consistent during daytime and in densely urbanized areas. ST_BTFA differences between urban and park/rural areas were higher during nighttime (above 1 °C than daytime (about 0.5 °C. These results could help to identify “urban thermal Hot-Spots” that would benefit most from mitigation actions.

  2. Assessing the relationship between surface urban heat islands and landscape patterns across climatic zones in China.

    Science.gov (United States)

    Yang, Qiquan; Huang, Xin; Li, Jiayi

    2017-08-24

    The urban heat island (UHI) effect exerts a great influence on the Earth's environment and human health and has been the subject of considerable attention. Landscape patterns are among the most important factors relevant to surface UHIs (SUHIs); however, the relationship between SUHIs and landscape patterns is poorly understood over large areas. In this study, the surface UHI intensity (SUHII) is defined as the temperature difference between urban and suburban areas, and the landscape patterns are quantified by the urban-suburban differences in several typical landscape metrics (ΔLMs). Temperature and land-cover classification datasets based on satellite observations were applied to analyze the relationship between SUHII and ΔLMs in 332 cities/city agglomerations distributed in different climatic zones of China. The results indicate that SUHII and its correlations with ΔLMs are profoundly influenced by seasonal, diurnal, and climatic factors. The impacts of different land-cover types on SUHIs are different, and the landscape patterns of the built-up and vegetation (including forest, grassland, and cultivated land) classes have the most significant effects on SUHIs. The results of this study will help us to gain a deeper understanding of the relationship between the SUHI effect and landscape patterns.

  3. Surface runoff water quality in a managed three zone riparian buffer.

    Science.gov (United States)

    Lowrance, Richard; Sheridan, Joseph M

    2005-01-01

    Managed riparian forest buffers are an important conservation practice but there are little data on the water quality effects of buffer management. We measured surface runoff volumes and nutrient concentrations and loads in a riparian buffer system consisting of (moving down slope from the field) a grass strip, a managed forest, and an unmanaged forest. The managed forest consisted of sections of clear-cut, thinned, and mature forest. The mature forest had significantly lower flow-weighted concentrations of nitrate, ammonium, total Kjeldahl N (TKN), sediment TKN, total N (nitrate + TKN), dissolved molybdate reactive P (DMRP), total P, and chloride. The average buffer represented the conditions along a stream reach with a buffer system in different stages of growth. Compared with the field output, flow-weighted concentrations of nitrate, ammonium, DMRP, and total P decreased significantly within the buffer and flow-weighted concentrations of TKN, total N, and chloride increased significantly within the buffer. All loads decreased significantly from the field to the middle of the buffer, but most loads increased from the middle of the buffer to the sampling point nearest the stream because surface runoff volume increased near the stream. The largest percentage reduction of the incoming nutrient load (at least 65% for all nutrient forms) took place in the grass buffer zone because of the large decrease (68%) in flow. The average buffer reduced loadings for all nutrient species, from 27% for TKN to 63% for sediment P. The managed forest and grass buffer combined was an effective buffer system.

  4. Mechanism study of initial filamentary damage in optical components owing to surface contamination particles

    Science.gov (United States)

    Sun, Xiaoyan; Lei, Zemin; Lu, Xingqiang; Fan, Dianyuan

    2015-07-01

    Contaminations existing inevitably in high-power laser facilities modulate laser beams and decrease beam quality. This study set up a detection system to study the mechanism of initial filamentary damage in optical components induced by surface contaminations. The effect of ordinary solid particles, liquid particles, and solid-liquid mixed particles on the near-field intensity distribution of laser beam was studied and analyzed statistically. The experiment results show that pure solid particles make the beam generate diffraction rings with dark center usually in the shadow of the particles which is a weak intensity modulation; pure liquid particles focus the localized beam into a bright spot rapidly, but it is diffracted away soon; solid-liquid mixed particles cause diffraction rings with strongly bright center, but the high local intensity can be diffracted away only after a longer distance, which is one of the reason that induces the initial filamentary damage to optical components. The research results can predict the likelihood of component damage, and the corresponding preventive measures help to keep the safe operation of high-power laser facilities.

  5. Dispersion of inorganic contaminants in surface water in the vicinity of Potchefstroom

    Science.gov (United States)

    Manyatshe, A.; Fosso-Kankeu, E.; van der Berg, D.; Lemmer, N.; Waanders, F.; Tutu, H.

    2017-08-01

    Potchefstroom and the neighbouring cities rely mostly on the Mooi River and Vaal River for their water needs. These rivers flow through the gold mining areas and farms, and are therefore likely to be contaminated with substantial amounts of inorganic pollutants. Water was collected along the rivers network, streams, canals and dams in Potchefstroom and the vicinity. The samples were characterized for geochemical parameters, metals and anions concentrations. The results showed high concentrations of potentially toxic elements such as As (4.53 mg/L - 5.74 mg/L), Cd (0.25 mg/L - 0.7 mg/L), Pb (1.14 mg/L - 5.13 mg/L) and U (0.04 mg/L - 0.11 mg/L) which were predominantly found around the mining areas. Elevated concentrations of anions such SO42- and CN- were detected around mining areas while NO3- was dominant near farms. The relatively high levels of anions and metals in the surface water made it unfit for domestic or agricultural use. The study showed that contaminants in mining and agricultural facilities were potentially mobilised, thus impacting the nearby water systems.

  6. Mechanism of cell integration on biomaterial implant surfaces in the presence of bacterial contamination.

    Science.gov (United States)

    Yue, Chongxia; van der Mei, Henny C; Kuijer, Roel; Busscher, Henk J; Rochford, Edward T J

    2015-11-01

    Bacterial contamination during biomaterial implantation is often unavoidable, yielding a combat between cells and bacteria. Here we aim to determine the modulatory function of bacterial components on stem-cell, fibroblast, and osteoblast adhesion to a titanium alloy, including the role of toll-like-receptors (TLRs). Presence of heat-sacrificed Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, or Pseudomonas aeruginosa induced dose and cell-type dependent responses. Stem-cells were most sensitive to bacterial presence, demonstrating decreased adhesion number yet increased adhesion effort with a relatively large focal adhesion contact area. Blocking TLRs had no effect on stem-cell adhesion in presence of S. aureus, but blocking both TLR2 and TLR4 induced an increased adhesion effort in presence of E. coli. Neither lipopolysaccharide, lipoteichoic acid, nor bacterial DNA provoked the same cell response as did whole bacteria. Herewith we suggest a new mechanism as to how biomaterials are integrated by cells despite the unavoidable presence of bacterial contamination. Stimulation of host cell integration of implant surfaces may open a new window to design new biomaterials with enhanced healing, thereby reducing the risk of biomaterial-associated infection of both "hardware-based" implants as well as of tissue-engineered constructs, known to suffer from similarly high infection risks as currently prevailing in "hardware-based" implants. © 2015 Wiley Periodicals, Inc.

  7. Assessment of metals contamination in Klang River surface sediments by using different indexes

    Directory of Open Access Journals (Sweden)

    Abolfazl Naji

    2011-01-01

    Full Text Available Surface sediments (0-5 cm from 21 stations throughout Klang River were sampled for metal concentration as well sediment's pH, total organic carbon (TOC and particles sizes to obtain an overall classification of metal contaminations in the area. The concentration of metals (µg∕g, Fe%, dw were as follows: 0.57- 2.19 Cd; 31.89-272.33 Zn; 5.96-24.47 Ni; 10.57- 52.87 Cu; 24.23-64.11 Pb and 1.56-3.03 Fe. The degree of sediment contaminations were computed using an enrichment factor (EF and geoaccumulation index (Igeo. The results suggested that enrichment factor and geoaccumulation values of Cd were greatest among the studied metals. Pearson's correlation indicated that effectiveness of TOC in controlling the distribution and enrichment of metals was a more important factor than that of the grain size (< 63µm. The study revealed that on the basis of computed indexes, Klang River is classified as moderately polluted river.

  8. Estimation of the amount of surface contamination of a water cooled nuclear reactor by cooling water analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, G. [KFKI Atomic Energy Research Institute, P.O. Box 49, Budapest H-1525 (Hungary)]. E-mail: nagyg@sunserv.kfki.hu; Somogyi, A. [KFKI Atomic Energy Research Institute, P.O. Box 49, Budapest H-1525 (Hungary); Patek, G. [Paks Nuclear Power Plant, P.O. Box 71, Paks H-7031 (Hungary); Pinter, T. [Paks Nuclear Power Plant, P.O. Box 71, Paks H-7031 (Hungary); Schiller, R. [KFKI Atomic Energy Research Institute, P.O. Box 49, Budapest H-1525 (Hungary)

    2007-06-15

    Calculations, based upon on-the-spot measurements, were performed to estimate the contamination of NPP primary circuit and spent fuel storage pool solid surfaces via the composition of the cooling water in connection with a non-nuclear incident in the Paks NPP. Thirty partially burnt-up fuel element bundles were damaged during a cleaning process, an incident which resulted in the presence of fission products in the cooling water of the cleaning tank (CT) situated in a separate pool (P1). Since this medium was in contact for an extended period of time with undamaged fuel elements to be used later and also with other structural materials of the spent fuel storage pool (SP), it was imperative to assess the surface contamination of these latter ones with a particular view to the amount of fission material. In want of direct methods, one was restricted to indirect information which rested mainly on the chemical and radiochemical data of the cooling water. It was found that (i) the most important contaminants were uranium, plutonium, cesium and cerium; (ii) after the isolation of P1 and SP and an extended period of filtering the only important contaminants were uranium and plutonium; (iii) the surface contamination of the primary circuit (PC) was much lower than that of either SP or P1; (iv) some 99% of the contamination was removed from the water by the end of the filtering process.

  9. Multicenter evaluation of a new closed system drug-transfer device in reducing surface contamination by antineoplastic hazardous drugs.

    Science.gov (United States)

    Bartel, Sylvia B; Tyler, Timothy G; Power, Luci A

    2018-02-15

    Results of a study to evaluate the effectiveness of a recently introduced closed system drug-transfer device (CSTD) in reducing surface contamination during compounding and simulated administration of antineoplastic hazardous drugs (AHDs) are reported. Wipe samples were collected from 6 predetermined surfaces in compounding and infusion areas of 13 U.S. cancer centers to establish preexisting levels of surface contamination by 2 marker AHDs (cyclophosphamide and fluorouracil). Stainless steel templates were placed over the 6 previously sampled surfaces, and the marker drugs were compounded and infused per a specific protocol using all components of the CSTD. Wipe samples were collected from the templates after completion of tasks and analyzed for both marker AHDs. Aggregated results of wipe sampling to detect preexisting contamination at the 13 study sites showed that overall, 66.7% of samples (104 of 156) had detectable levels of at least 1 marker AHD; subsequent testing after CSTD use per protocol found a sample contamination rate of 5.8% (9 of 156 samples). In the administration areas alone, the rate of preexisting contamination was 78% (61 of 78 samples); with use of the CSTD protocol, the contamination rate was 2.6%. Twenty-six participants rated the CSTD for ease of use, with 100% indicating that they were satisfied or extremely satisfied. A study involving a rigorous protocol and 13 cancer centers across the United States demonstrated that the CSTD reduced surface contamination by cyclophosphamide and fluorouracil during compounding and simulated administration. Participants reported that the CSTD was easy to use. Copyright © 2018 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  10. Using vadose zone data and spatial statistics to assess the impact of cultivated land and dairy waste lagoons on groundwater contamination

    Science.gov (United States)

    Baram, S.; Ronen, Z.; Kurtzman, D.; Peeters, A.; Dahan, O.

    2013-12-01

    Land cultivation and dairy waste lagoons are considered to be nonpoint and point sources of groundwater contamination by chloride (Cl-) and nitrate (NO3-). The objective of this work is to introduce a methodology to assess the past and future impacts of such agricultural activities on regional groundwater quality. The method is based on mass balances and on spatial statistical analysis of Cl- and NO3-concentration distributions in the saturated and unsaturated zones. The method enables quantitative analysis of the relation between the locations of pollution point sources and the spatial variability in Cl- and NO3- concentrations in groundwater. The method was applied to the Beer-Tuvia region, Israel, where intensive dairy farming along with land cultivation has been practiced for over 50 years above the local phreatic aquifer. Mass balance calculations accounted for the various groundwater recharge and abstraction sources and sinks in the entire region. The mass balances showed that leachates from lagoons and the cultivated land have contributed 6.0 and 89.4 % of the total mass of Cl- added to the aquifer and 12.6 and 77.4 % of the total mass of NO3-. The chemical composition of the aquifer and vadose zone water suggested that irrigated agricultural activity in the region is the main contributor of Cl- and NO3- to the groundwater. A low spatial correlation between the Cl- and NO3- concentrations in the groundwater and the on-land location of the dairy farms strengthened this assumption, despite the dairy waste lagoon being a point source for groundwater contamination by Cl- and NO3-. Results demonstrate that analyzing vadose zone and groundwater data by spatial statistical analysis methods can significantly contribute to the understanding of the relations between groundwater contaminating sources, and to assessing appropriate remediation steps.

  11. Laser-induced damage of fused silica at 355 and 1065 nm initiated at aluminum contamination particles on the surface

    International Nuclear Information System (INIS)

    Genin, F.Y.; Michlitsch, K.; Furr, J.; Kozlowski, M.R.; Krulevitch, P.

    1997-01-01

    1-μm thick circular dots, 10-250 μm dia, were deposited onto 1.14 cm thick fused silica windows by sputtering Al through a mask. Al shavings were also deposited on the windows to investigate effects of particle-substrate adhesion. The silica windows were then illuminated repetitively using a 3-ns, 355 nm and an 8.6-ns, 1064 nm laser. The tests were conducted at near normal incidence with particles on input and output surfaces of the windows. During the first shot, a plasma ignited at the metal particle and damage initiated on the fused silica surface. The morphology of the damage at the metal dots were reproducible but different for input and output surface contamination. For input surface contamination, minor damage occurred where the particle was located; such damage ceased to grow with the removal of contaminant material. More serious damage (pits and cracks) was initiated on the output surface (especially at 355 nm) and grew to catastrophic proportions after few shots. Output surface contaminants were usually ejected on the initial shot, leaving a wave pattern on the surface. No further damage occurred with subsequent shots unless a shot (usually the first shot) cracked the surface; such behavior was mostly observed at 355 nm and occasionally for large shavings at 1064 nm. The size of the damaged area scaled with the size of the particle (except when catastrophic damage occurred). Onset of catastrophic damage on output surface occurred only when particles exceeded a critical size. Damage behavior of the sputtered dots was found to be qualitatively similar to that of the shavings. The artificial contamination technique accelerated the study by allowing better control of the test conditions

  12. Radioecological state of some surface water systems of contaminated areas of both Gomel and Mogilev Regions

    International Nuclear Information System (INIS)

    Datskevich, P. I.; Komissariv, F. D.; Khvale', O. D.; Basharina, L. P.; Lobach, I. L.

    1997-01-01

    The radioecological situation of different ecosystems of Belarus and their components has been analysed. Such components of the surface water ecosystems as water, suspensions, sediments and soils of water-collection areas were used for the investigation of the content of cesium 137 and strontium 90. The received data were given since 1990. The content of cesium 137 and strontium 90 in the components of water ecosystems was counted in the laboratory conditions by means of standard methods of beta radiometry, semiconductor gamma spectrometry and radiochemistry. The error of measurement of radioactivity was not higher than 25 and 35% for cesium 137 and strontium 90 accordingly. Water ecosystems were distinguished by the state of contamination of water-collection areas and hydrological parameters. These and some other reasons considered in the article influence on the character of cesium 137 and strontium 90 behaviour in water ecosystems

  13. Global occurrence of anti-infectives in contaminated surface waters: Impact of income inequality between countries.

    Science.gov (United States)

    Segura, Pedro A; Takada, Hideshige; Correa, José A; El Saadi, Karim; Koike, Tatsuya; Onwona-Agyeman, Siaw; Ofosu-Anim, John; Sabi, Edward Benjamin; Wasonga, Oliver V; Mghalu, Joseph M; dos Santos Junior, Antonio Manuel; Newman, Brent; Weerts, Steven; Yargeau, Viviane

    2015-07-01

    The presence anti-infectives in environmental waters is of interest because of their potential role in the dissemination of anti-infective resistance in bacteria and other harmful effects on non-target species such as algae and shellfish. Since no information on global trends regarding the contamination caused by these bioactive substances is yet available, we decided to investigate the impact of income inequality between countries on the occurrence of anti-infectives in surface waters. In order to perform such study, we gathered concentration values reported in the peer-reviewed literature between 1998 and 2014 and built a database. To fill the gap of knowledge on occurrence of anti-infectives in African countries, we also collected 61 surface water samples from Ghana, Kenya, Mozambique and South Africa, and measured concentrations of 19 anti-infectives. A mixed one-way analysis of covariance (ANCOVA) model, followed by Turkey-Kramer post hoc tests was used to identify potential differences in anti-infective occurrence between countries grouped by income level (high, upper-middle and lower-middle and low income) according to the classification by the World Bank. Comparison of occurrence of anti-infectives according to income level revealed that concentrations of these substances in contaminated surface waters were significantly higher in low and lower-middle income countries (p=0.0001) but not in upper-middle income countries (p=0.0515) compared to high-income countries. We explained these results as the consequence of the absence of or limited sewage treatment performed in lower income countries. Furthermore, comparison of concentrations of low cost anti-infectives (sulfonamides and trimethoprim) and the more expensive macrolides between income groups suggest that the cost of these substances may have an impact on their environmental occurrence in lower income countries. Since wastewaters are the most important source of contamination of anti-infectives and other

  14. Imaging technique for detection of leaf surface contaminations with fission fragments

    International Nuclear Information System (INIS)

    Furuta, Etsuko

    2011-01-01

    Fission fragments by the Fukushima Daiichi catastrophe were scattered over a large area. Between Tokyo and Fukushima, leaves were gathered up from March to June and measured their radioactivities by HPGe. Radionuclides of 129m Tc, 131 I, 134 Cs and 137 Cs were rightly detected. Also the leaf surface contaminations were shown as images by imaging technique which detected beta- and gamma-rays exposure. The clear images were gotten within 24 h exposure though a normal leaf image needs at least one week exposure in a shield box. The total PSL values of leaves depend on their activities of sampling points, so the imaging technique is able to use for detection of the spread of fission fragments and the relative concentration. Also the rain effect to leaves could be shown by imaging technique when leaves were washed in running water. The imaging technique is easy and useful for the nuclear catastrophe. (author)

  15. Removal of Airborne Contaminants from a Surface Tank by a Push-Pull System

    DEFF Research Database (Denmark)

    Heiselberg, Per; Topp, Claus

    Open surface tanks are used in many industrial processes, and local exhaust systems are often designed to capture and remove toxic fumes diffused from materials in the tanks prior to their escape into the workplace environment. The push-pull system seems to be the most efficient local exhaust...... system, but proper design is required to ensure health and safety of the workers and, furthermore, it is very desirable from an energy conservation point of view to determine an optimum and -an efficient design of push-pull hoods which can exhaust all contaminants with a minimum quantity of volume flow....... The paper describes and discusses different design methods and compares designed values with results from a measurement series of push-pull system efficiency....

  16. Absorption and backscatter of internal conversion electrons in the measurements of surface contamination of 137Cs

    International Nuclear Information System (INIS)

    Yunoki, A.; Kawada, Y.; Yamada, T.; Unno, Y.; Sato, Y.; Hino, Y.

    2013-01-01

    We measured 4π and 2π counting efficiencies for internal conversion electrons (ICEs), gross β-particles and also β-rays alone with various source conditions regarding absorber and backing foil thickness using e-X coincidence technique. Dominant differences regarding the penetration, attenuation and backscattering properties among ICEs and β-rays were revealed. Although the abundance of internal conversion electrons of 137 Cs- 137 Ba is only 9.35%, 60% of gross counts may be attributed to ICEs in worse source conditions. This information will be useful for radionuclide metrology and for surface contamination monitoring. - Highlights: • Counting efficiencies for internal conversion electrons from 137 Cs were measured, and compared with those for β-rays. • Electron-X coincidence technique was employed. • A thin NaI(Tl) scintillation detector was used for X-ray detection. • Backscattering fractions of electrons and beta particles were studied by similar experiments

  17. Integrated Assessment of the impact of Aqueous Contaminant Stressors on Surface Water Ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Rasmussen, Jes J.; Kronvang, Brian

    2011-01-01

    ecosystems. Traditional approaches for managing aquatic resources have often failed to account for the potential effects of anthropogenic disturbances on biota. To fulfil the requirements of the EU Water Framework Directive will be challenging, as it is difficult to successfully separate and evaluate all...... pressures stressing an ecosystem. Here, methods for determining ecological status in streams are evaluated to see if they are capable of capturing the effects of stressors potentially affecting ecosystems. Specifically, they are tested on a case study where the effects of physical habitat degradation can...... carried out in summer 2010. The campaign included an analysis of xenobiotics in surface water, inorganic chemistry, diffuse source (run-off) impacts and ecology along a gradient of contamination in the stream. Modelling results indicate that naphthalene, glyphosate and 4-nonylphenol could adversely impact...

  18. The Mobile Surface Contamination Monitor II environmental radiological characterization utilizing GPS/GIS technologies

    International Nuclear Information System (INIS)

    Wendling, M.A.

    1993-05-01

    Time, cost, and most importantly quality of data are the three factors to measure the success of field radiological characterizations. The application of coupling radiation detection instrumentation to a GPS receiver has dramatically increased the data quality achievable compared to traditional environmental radiological survey methods. Improvements in verifying adequate spatial coverage of an area while collecting data and at,the same time reducing field time requirements can be realized. Data acquired during the recent implementation of the Mobile Surface Contamination Monitor 11 (MSCM-11) will be presented to demonstrate the advantages of this system over traditional radiological survey methods. The comparison will include time and manpower requirements. Linking the complimentary GPS, GIS and radiation detection technologies on a mobile tractor based platform has provided a tool to provide radiological characterization data faster, cheaper, and better to assist in the Environmental Restoration Mission of the Hanford Site

  19. Surface and subsurface continuous gravimetric monitoring of groundwater recharge processes through the karst vadose zone at Rochefort Cave (Belgium)

    Science.gov (United States)

    Watlet, A.; Van Camp, M. J.; Francis, O.; Poulain, A.; Hallet, V.; Triantafyllou, A.; Delforge, D.; Quinif, Y.; Van Ruymbeke, M.; Kaufmann, O.

    2017-12-01

    Ground-based gravimetry is a non-invasive and integrated tool to characterize hydrological processes in complex environments such as karsts or volcanoes. A problem in ground-based gravity measurements however concerns the lack of sensitivity in the first meters below the topographical surface, added to limited infiltration below the gravimeter building (umbrella effect). Such limitations disappear when measuring underground. Coupling surface and subsurface gravity measurements therefore allow isolating hydrological signals occurring in the zone between the two gravimeters. We present a coupled surface/subsurface continuous gravimetric monitoring of 2 years at the Rochefort Cave Laboratory (Belgium). The gravity record includes surface measurements of a GWR superconducting gravimeter and subsurface measurements of a Micro-g LaCoste gPhone gravimeter, installed in a cave 35 m below the surface station. The recharge of karstic aquifers is extremely complex to model, mostly because karst hydrological systems are composed of strongly heterogeneous flows. Most of the problem comes from the inadequacy of conventional measuring tools to correctly sample such heterogeneous media, and particularly the existence of a duality of flow types infiltrating the vadose zone: from rapid flows via open conduits to slow seepage through porous matrix. Using the surface/subsurface gravity difference, we were able to identify a significant seasonal groundwater recharge within the karst vadose zone. Seasonal or perennial perched reservoirs have already been proven to exist in several karst areas due to the heterogeneity of the porosity and permeability gradient in karstified carbonated rocks. Our gravimetric experiment allows assessing more precisely the recharge processes of such reservoirs. The gravity variations were also compared with surface and in-cave hydrogeological monitoring (i.e. soil moisture, in-cave percolating water discharges, water levels of the saturated zone). Combined

  20. Neural Network-Based Retrieval of Surface and Root Zone Soil Moisture using Multi-Frequency Remotely-Sensed Observations

    Science.gov (United States)

    Hamed Alemohammad, Seyed; Kolassa, Jana; Prigent, Catherine; Aires, Filipe; Gentine, Pierre

    2017-04-01

    Knowledge of root zone soil moisture is essential in studying plant's response to different stress conditions since plant photosynthetic activity and transpiration rate are constrained by the water available through their roots. Current global root zone soil moisture estimates are based on either outputs from physical models constrained by observations, or assimilation of remotely-sensed microwave-based surface soil moisture estimates with physical model outputs. However, quality of these estimates are limited by the accuracy of the model representations of physical processes (such as radiative transfer, infiltration, percolation, and evapotranspiration) as well as errors in the estimates of the surface parameters. Additionally, statistical approaches provide an alternative efficient platform to develop root zone soil moisture retrieval algorithms from remotely-sensed observations. In this study, we present a new neural network based retrieval algorithm to estimate surface and root zone soil moisture from passive microwave observations of SMAP satellite (L-band) and AMSR2 instrument (X-band). SMAP early morning observations are ideal for surface soil moisture retrieval. AMSR2 mid-night observations are used here as an indicator of plant hydraulic properties that are related to root zone soil moisture. The combined observations from SMAP and AMSR2 together with other ancillary observations including the Solar-Induced Fluorescence (SIF) estimates from GOME-2 instrument provide necessary information to estimate surface and root zone soil moisture. The algorithm is applied to observations from the first 18 months of SMAP mission and retrievals are validated against in-situ observations and other global datasets.

  1. Steam stripping of the unsaturated zone of contaminated sub-soils: The effect of diffusion/dispersion in the start-up phase

    Science.gov (United States)

    Brouwers, H. J. H.; Gilding, B. H.

    2006-02-01

    The unsteady process of steam stripping of the unsaturated zone of soils contaminated with volatile organic compounds (VOCs) is addressed. A model is presented. It accounts for the effects of water and contaminants remaining in vapour phase, as well as diffusion and dispersion of contaminants in this phase. The model has two components. The first is a one-dimensional description of the propagation of a steam front in the start-up phase. This is based on Darcy's law and conservation laws of mass and energy. The second component describes the transport of volatile contaminants. Taking the view that non-equilibrium between liquid and vapour phases exists, it accounts for evaporation, transport, and condensation at the front. This leads to a moving-boundary problem. The moving-boundary problem is brought into a fixed domain by a suitable transformation of the governing partial differential equations, and solved numerically. For a broad range of the governing dimensionless numbers, such as the Henry, Merkel and Péclet numbers, computational results are discussed. A mathematical asymptotic analysis supports this discussion. The range of parameter values for which the model is valid is investigated. Diffusion and dispersion are shown to be of qualitative importance, but to have little quantitative effect in the start-up phase.

  2. The technique for determination of surface contamination by uranium on U3Si2-Al plate-type fuel elements

    International Nuclear Information System (INIS)

    Li Shulan; He Fengqi; Wang Qingheng; Han Jingquan

    1993-04-01

    The NDT method for determining the surface contamination by uranium on U 3 Si 2 -Al plate-type fuel elements, the process of standard specimen preparation and the graduation curve are described. The measurement results of U 3 Si 2 -Al plate-type fuel elements show that the alpha counting method to measure the surface contamination by uranium on fuel plate is more reliable. The UB-1 type surface contamination meter, which was recently developed, has many advantages such as high sensitivity to determine the uranium pollution, short time in measuring, convenience for operation, and the minimum detectable amount of uranium is 5 x 10 -10 g/cm 2 . The measuring device is controlled by a microcomputer. Besides data acquisition and processing, it has functions of statistics, output data on terminal or to printer and alarm. The procedures of measurement are fully automatic. All of these will meet the measuring needs in batch process

  3. Understanding the Hydromechanical Behavior of a Fault Zone From Transient Surface Tilt and Fluid Pressure Observations at Hourly Time Scales

    Science.gov (United States)

    Schuite, Jonathan; Longuevergne, Laurent; Bour, Olivier; Burbey, Thomas J.; Boudin, Frédérick; Lavenant, Nicolas; Davy, Philippe

    2017-12-01

    Flow through reservoirs such as fractured media is powered by head gradients which also generate measurable poroelastic deformation of the rock body. The combined analysis of surface deformation and subsurface pressure provides valuable insights of a reservoir's structure and hydromechanical properties, which are of interest for deep-seated CO2 or nuclear waste storage for instance. Among all surveying tools, surface tiltmeters offer the possibility to grasp hydraulically induced deformations over a broad range of time scales with a remarkable precision. Here we investigate the information content of transient surface tilt generated by the pressurization a kilometer scale subvertical fault zone. Our approach involves the combination of field data and results of a fully coupled poromechanical model. The signature of pressure changes in the fault zone due to pumping cycles is clearly recognizable in field tilt data and we aim to explain the peculiar features that appear in (1) tilt time series alone from a set of four instruments and 2) the ratio of tilt over pressure. We evidence that the shape of tilt measurements on both sides of a fault zone is sensitive to its diffusivity and its elastic modulus. The ratio of tilt over pressure predominantly encompasses information about the system's dynamic behavior and extent of the fault zone and allows separating contributions of flow in the different compartments. Hence, tiltmeters are well suited to characterize hydromechanical processes associated with fault zone hydrogeology at short time scales, where spaceborne surveying methods fail to recognize any deformation signal.

  4. Spatial and Temporal Variability in Nitrate Concentration below the Root Zone in an Almond Orchard and its Implications for Potential Groundwater Contamination

    Science.gov (United States)

    Baram, S.; Couvreur, V.

    2015-12-01

    Spatial and Temporal Variability in Nitrate Concentration below the Root Zone in an Almond Orchard and its Implications for Potential Groundwater Contamination S. Baram1, M. Read1, D. Smart2, T. Harter1, J Hopmans11Department of Land, Air & Water Resources University of California Davis 2Department of Viticulture and Enology University of California Davis Estimates of water and fertilizer losses below the root zone of nitrogen (N) intensive agricultural orchard crops are major concern in groundwater protection. However, microscopic and macroscopic heterogeneity in unsaturated soils make accurate loss estimates very challenging. In this study we aimed to examine field scale variability in nitrate (NO3-) losses below the root zone (>250cm) of a 15 years old almond orchard in Madera county California. Based on a soil variability survey, tensiometers and solution samplers were installed at 17 locations around the 40 acre orchard. The hydraulic potential and the NO3- concentrations were monitored over two growing seasons. Nitrate concentrations varied spatially and temporarily, and ranged from below to more than 30 times higher than the drinking water contamination standard of >10 mg NO3--N L-1. Principal component analysis of the relations between the NO3- concentration, presence of a hard pan in the subsurface, its depth and thickness, and the fertigation and irrigation events indicated that none of these factors explained the observed variability in pore-water NO3- concentrations, with hard pan being the most dominant factor. Throughout the irrigation season minimal leaching was observed, yet post-harvest and preseason flooding events led to deep drainage. Due to the high spatial and temporal variability in the NO3- concentration and the potential for deep drainage following a wet winter or flooding event we conclude that the most efficient way to protect ground water is by transitioning to high frequency low nitrogen fertigation which would retain NO3-in the active

  5. Model assessment of additional contamination of water bodies as a result of wildfires in the Chernobyl exclusion zone.

    Science.gov (United States)

    Bondar, Yu I; Navumau, A D; Nikitin, A N; Brown, J; Dowdall, M

    2014-12-01

    Forest fires and wild fires are recognized as a possible cause of resuspension and redistribution of radioactive substances when occurring on lands contaminated with such materials, and as such are a matter of concern within the regions of Belarus and the Ukraine which were contaminated by the Chernobyl accident in 1986. Modelling the effects of such fires on radioactive contaminants is a complex matter given the number of variables involved. In this paper, a probabilistic model was developed using empirical data drawn from the Polessie State Radiation-Ecological Reserve (PSRER), Belarus, and the Maximum Entropy Method. Using the model, it was possible to derive estimates of the contribution of fire events to overall variability in the levels of (137)Cs and (239,240)Pu in ground air as well as estimates of the deposition of these radionuclides to specific water bodies within the contaminated areas of Belarus. Results indicate that fire events are potentially significant redistributors of radioactive contaminants within the study area and may result in additional contamination being introduced to water bodies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Water treatment strategy for underground and surface waters in order to reduce the hydro-network contamination due to close out of a uranium mining area in Romania

    International Nuclear Information System (INIS)

    Georgescu, D.; Radulescu, C.

    1999-01-01

    Under the present circumstances, in correlation with the national nuclear program and strategy, it is foreseen to stop the exploitation activities in two important uranium mining areas from Romania. This close-out action is involving a number of technical decisions for environmental restoration. Reduction of waters radioactive contamination in these zones, both during the operating period and after the closeout period, is one of the main components of the environment rehabilitation strategy. In this paper there are presented the today situation and the program foreseen for ground and surface water treatment at an uranium mining unit situated in the SW side of Romania, program based on the results of our own research carried out to decrease the content of pollutant radioactive elements. (author)

  7. A risk-informed basis for establishing non-fixed surface contamination limits for spent fuel transportation casks

    International Nuclear Information System (INIS)

    Rawl, R.R.; Eckerman, K.F.; Bogard, J.S.; Cook, J.R.

    2004-01-01

    The current limits for non-fixed contamination on packages used to transport radioactive materials were introduced in the 1961 edition of the International Atomic Energy Agency (IAEA) transport regulations and were based on radiation protection guidance and practices in use at that time. The limits were based on exposure scenarios leading to intakes of radionuclides by inhalation and external irradiation of the hands. These considerations are collectively referred to as the Fairbairn model. Although formulated over 40 years ago, the model remains unchanged and is still the basis of current regulatory-derived limits on package non-fixed surface contamination. There can also be doses that while not resulting directly from the contamination, are strongly influenced by and attributable to transport regulatory requirements for contamination control. For example, actions necessary to comply with the current derived limits for light-water-reactor (LWR) spent nuclear fuel (SNF) casks can result in significant external doses to workers. This is due to the relatively high radiation levels around the loaded casks, where workers must function during the measurement of contamination levels and while decontaminating the cask. In order to optimize the total dose received due to compliance with cask contamination levels, it is necessary to take into account all the doses that vary as a result of the regulatory limit. Limits for non-fixed surface contamination on spent fuel casks should be established by using a model that considers and optimizes the appropriate exposure scenarios both in the workplace and in the public environment. A risk-informed approach is needed to ensure optimal use of personnel and material resources for SNF-based packaging operations. This paper is a summary of a study sponsored by the US Nuclear Regulatory Commission and performed by Oak Ridge National Laboratory that examined the dose implications for removable surface contamination limits on spent fuel

  8. Observations of surface momentum exchange over the marginal ice zone and recommendations for its parametrisation

    Directory of Open Access Journals (Sweden)

    A. D. Elvidge

    2016-02-01

    Full Text Available Comprehensive aircraft observations are used to characterise surface roughness over the Arctic marginal ice zone (MIZ and consequently make recommendations for the parametrisation of surface momentum exchange in the MIZ. These observations were gathered in the Barents Sea and Fram Strait from two aircraft as part of the Aerosol–Cloud Coupling And Climate Interactions in the Arctic (ACCACIA project. They represent a doubling of the total number of such aircraft observations currently available over the Arctic MIZ. The eddy covariance method is used to derive estimates of the 10 m neutral drag coefficient (CDN10 from turbulent wind velocity measurements, and a novel method using albedo and surface temperature is employed to derive ice fraction. Peak surface roughness is found at ice fractions in the range 0.6 to 0.8 (with a mean interquartile range in CDN10 of 1.25 to 2.85  ×  10−3. CDN10 as a function of ice fraction is found to be well approximated by the negatively skewed distribution provided by a leading parametrisation scheme (Lüpkes et al., 2012 tailored for sea-ice drag over the MIZ in which the two constituent components of drag – skin and form drag – are separately quantified. Current parametrisation schemes used in the weather and climate models are compared with our results and the majority are found to be physically unjustified and unrepresentative. The Lüpkes et al. (2012 scheme is recommended in a computationally simple form, with adjusted parameter settings. A good agreement holds for subsets of the data from different locations, despite differences in sea-ice conditions. Ice conditions in the Barents Sea, characterised by small, unconsolidated ice floes, are found to be associated with higher CDN10 values – especially at the higher ice fractions – than those of Fram Strait, where typically larger, smoother floes are observed. Consequently, the important influence of sea-ice morphology and floe size on

  9. Observations of surface momentum exchange over the marginal ice zone and recommendations for its parametrisation

    Science.gov (United States)

    Elvidge, A. D.; Renfrew, I. A.; Weiss, A. I.; Brooks, I. M.; Lachlan-Cope, T. A.; King, J. C.

    2016-02-01

    Comprehensive aircraft observations are used to characterise surface roughness over the Arctic marginal ice zone (MIZ) and consequently make recommendations for the parametrisation of surface momentum exchange in the MIZ. These observations were gathered in the Barents Sea and Fram Strait from two aircraft as part of the Aerosol-Cloud Coupling And Climate Interactions in the Arctic (ACCACIA) project. They represent a doubling of the total number of such aircraft observations currently available over the Arctic MIZ. The eddy covariance method is used to derive estimates of the 10 m neutral drag coefficient (CDN10) from turbulent wind velocity measurements, and a novel method using albedo and surface temperature is employed to derive ice fraction. Peak surface roughness is found at ice fractions in the range 0.6 to 0.8 (with a mean interquartile range in CDN10 of 1.25 to 2.85 × 10-3). CDN10 as a function of ice fraction is found to be well approximated by the negatively skewed distribution provided by a leading parametrisation scheme (Lüpkes et al., 2012) tailored for sea-ice drag over the MIZ in which the two constituent components of drag - skin and form drag - are separately quantified. Current parametrisation schemes used in the weather and climate models are compared with our results and the majority are found to be physically unjustified and unrepresentative. The Lüpkes et al. (2012) scheme is recommended in a computationally simple form, with adjusted parameter settings. A good agreement holds for subsets of the data from different locations, despite differences in sea-ice conditions. Ice conditions in the Barents Sea, characterised by small, unconsolidated ice floes, are found to be associated with higher CDN10 values - especially at the higher ice fractions - than those of Fram Strait, where typically larger, smoother floes are observed. Consequently, the important influence of sea-ice morphology and floe size on surface roughness is recognised, and

  10. Observations of surface momentum exchange over the marginal-ice-zone and recommendations for its parameterization

    Science.gov (United States)

    Elvidge, A. D.; Renfrew, I. A.; Weiss, A. I.; Brooks, I. M.; Lachlan-Cope, T. A.; King, J. C.

    2015-10-01

    Comprehensive aircraft observations are used to characterise surface roughness over the Arctic marginal ice zone (MIZ) and consequently make recommendations for the parameterization of surface momentum exchange in the MIZ. These observations were gathered in the Barents Sea and Fram Strait from two aircraft as part of the Aerosol-Cloud Coupling And Climate Interactions in the Arctic (ACCACIA) project. They represent a doubling of the total number of such aircraft observations currently available over the Arctic MIZ. The eddy covariance method is used to derive estimates of the 10 m neutral drag coefficient (CDN10) from turbulent wind velocity measurements, and a novel method using albedo and surface temperature is employed to derive ice fraction. Peak surface roughness is found at ice fractions in the range 0.6 to 0.8 (with a mean interquartile range in CDN10 of 1.25 to 2.85 × 10-3). CDN10 as a function of ice fraction is found to be well approximated by the negatively skewed distribution provided by a leading parameterization scheme (Lüpkes et al., 2012) tailored for sea ice drag over the MIZ in which the two constituent components of drag - skin and form drag - are separately quantified. Current parameterization schemes used in the weather and climate models are compared with our results and the majority are found to be physically unjustified and unrepresentative. The Lüpkes et al. (2012) scheme is recommended in a computationally simple form, with adjusted parameter settings. A good agreement is found to hold for subsets of the data from different locations despite differences in sea ice conditions. Ice conditions in the Barents Sea, characterised by small, unconsolidated ice floes, are found to be associated with higher CDN10 values - especially at the higher ice fractions - than those of Fram Strait, where typically larger, smoother floes are observed. Consequently, the important influence of sea ice morphology and floe size on surface roughness is

  11. Characterization of dissolved organic materials in surface waters within the blast zone of Mount St Helens, Washington

    Science.gov (United States)

    McKnight, Diane M.; Pereira, W.E.; Ceazan, M.L.; Wissmar, Robert C.

    1982-01-01

    After the May 18, 1980, eruption of Mount St Helens, the concentration of dissolved organic material in surface waters near the volcano increased significantly as a result of the destruction of the surrounding conifer forest. Low molecular weight organic compounds identified in the blast zone surface waters were derived from pyrolysis of plant and soil organic materials incorporated into pyroclastic flow, mud flow and debris avalanche deposits. A major fraction of the dissolved organic material consisted of high molecular weight, colored, organic acids that are similar in their general properties to aquatic fulvic acids found in more typical surface waters except for greater sulfur contents. The other major fraction of the dissolved organic material consisted of hydrophilic acids, which may include compounds capable of supporting heterotrophic microorganisms, and precursors in the formation of aquatic fulvic acids. The organic chemistry of blast zone surface waters will probably be greatly influenced by the May 18, 1980, eruption for many years. ?? 1982.

  12. A hybrid machine learning model to estimate nitrate contamination of production zone groundwater in the Central Valley, California

    Science.gov (United States)

    Ransom, K.; Nolan, B. T.; Faunt, C. C.; Bell, A.; Gronberg, J.; Traum, J.; Wheeler, D. C.; Rosecrans, C.; Belitz, K.; Eberts, S.; Harter, T.

    2016-12-01

    A hybrid, non-linear, machine learning statistical model was developed within a statistical learning framework to predict nitrate contamination of groundwater to depths of approximately 500 m below ground surface in the Central Valley, California. A database of 213 predictor variables representing well characteristics, historical and current field and county scale nitrogen mass balance, historical and current landuse, oxidation/reduction conditions, groundwater flow, climate, soil characteristics, depth to groundwater, and groundwater age were assigned to over 6,000 private supply and public supply wells measured previously for nitrate and located throughout the study area. The machine learning method, gradient boosting machine (GBM) was used to screen predictor variables and rank them in order of importance in relation to the groundwater nitrate measurements. The top five most important predictor variables included oxidation/reduction characteristics, historical field scale nitrogen mass balance, climate, and depth to 60 year old water. Twenty-two variables were selected for the final model and final model errors for log-transformed hold-out data were R squared of 0.45 and root mean square error (RMSE) of 1.124. Modeled mean groundwater age was tested separately for error improvement in the model and when included decreased model RMSE by 0.5% compared to the same model without age and by 0.20% compared to the model with all 213 variables. 1D and 2D partial plots were examined to determine how variables behave individually and interact in the model. Some variables behaved as expected: log nitrate decreased with increasing probability of anoxic conditions and depth to 60 year old water, generally decreased with increasing natural landuse surrounding wells and increasing mean groundwater age, generally increased with increased minimum depth to high water table and with increased base flow index value. Other variables exhibited much more erratic or noisy behavior in

  13. Heavy Metal Contamination in the Surface Sediments of Representative Limnetic Ecosystems in Eastern China

    Science.gov (United States)

    Tang, Wenzhong; Shan, Baoqing; Zhang, Hong; Zhang, Wenqiang; Zhao, Yu; Ding, Yuekui; Rong, Nan; Zhu, Xiaolei

    2014-11-01

    A comprehensive analysis of heavy metal pollution was conducted in the representative limnetic ecosystems of eastern China, which are subject to rapid economic development and population growth. The results demonstrated that the average contents with standard deviations of Cd, Cr, Cu, Ni, Pb and Zn in the surface sediments were 0.925 +/- 0.936, 142 +/- 46.8, 54.7 +/- 29.1, 60.5 +/- 21.6, 61.9 +/- 36.0 and 192 +/- 120 mg/kg dry wt., respectively, and that higher values were mainly observed in the southern portion of the study area, especially in the basins of Southeast Coastal Rivers (SCRB) and the Zhu River (ZRB). The six heavy metals in the surface sediments all had anthropogenic origins. In addition, the limnetic ecosystems, especially in the southern portion of the study area were found to be polluted by heavy metals, especially Cd. Overall, two hotspots of heavy metal pollution in the limnetic ecosystems of eastern China were found, one that consisted of the heavy pollution regions, SCRB and ZRB, and another composed of Cd pollution. These results indicate that heavy metal contamination, especially Cd, should be taken into account during development of management strategies to protect the aquatic environment in the limnetic ecosystems of eastern China, especially in the two aforementioned basins.

  14. Ag Nanorod Arrays for SERS: Aspects of Spectral Reproducibility, Surface Contamination, and Spectral Sensitivity

    Directory of Open Access Journals (Sweden)

    Martin Šubr

    2015-01-01

    Full Text Available Ag nanorod arrays prepared by oblique angle vapor deposition (OAD represent regular, large area substrates for surface-enhanced Raman scattering (SERS spectroscopy. We studied uniformity and spectral reproducibility of silver OAD-fabricated substrates (AgOADs by spectral mapping of methylene blue. The results demonstrate good reproducibility apart from occasional “hot-spot” sites where the intensity is higher. The number of “hot-spots” represents 2%–6% of SERS-active sites of mapping substrate area. We were able to obtain good SERS spectra of testing amino acid tryptophan at 1 × 10−5 M concentration and three different free-base porphyrins down to ∼10−7 M concentration. We found out that keeping the AgOADs in a vacuum chamber overnight prevents the surface from binding any contaminants from the ambient atmosphere, without significant reduction in the SERS enhancement. Such substrates provide stable SERS enhancement even when stored for 1 year after preparation.

  15. The BetaCage, an ultra-sensitive screener for surface contamination

    Energy Technology Data Exchange (ETDEWEB)

    Bunker, R.; Bowles, M. A.; Schnee, R. W.; Wang, B. [Department of Physics, Syracuse University, Syracuse, NY 13244 (United States); Ahmed, Z.; Golwala, S. R.; Nelson, R. H.; Rider, A.; Zahn, A. [California Institute of Technology, Pasadena, CA 91125 (United States); Grant, D. R. [University of Alberta, Edmonton, AB, T6G 2R3 (Canada); Kos, M. [Department of Physics, Syracuse University, Syracuse, NY 13244, USA and Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

    2013-08-08

    Material screening for identifying low-energy electron emitters and alpha-decaying isotopes is now a prerequisite for rare-event searches (e.g., dark-matter direct detection and neutrinoless double-beta decay) for which surface radiocon-tamination has become an increasingly important background. The BetaCage, a gaseous neon time-projection chamber, is a proposed ultra-sensitive (and nondestructive) screener for alpha-and beta-emitting surface contaminants to which existing screening facilities are insufficiently sensitive. Sensitivity goals are 0.1 betas keV{sup −1} m{sup −2} day{sup −1} and 0.1 alphas m{sup −2} day{sup −1}, with the former limited by Compton scattering of photons in the screening samples and (thanks to tracking) the latter expected to be signal-limited; radioassays and simulations indicate backgrounds from detector materials and radon daughters should be subdominant. We report on details of the background simulations and detector design that provide the discrimination, shielding, and radiopurity necessary to reach our sensitivity goals for a chamber with a 95 × 95 cm{sup 2} sample area positioned below a 40 cm drift region and monitored by crisscrossed anode and cathode planes consisting of 151 wires each.

  16. Evaluation of the contribution of contamination of radiotherapy room surfaces in the measure of exposure rate of radioiodine therapy patients

    International Nuclear Information System (INIS)

    Campos, Rafael Ferreira

    2015-01-01

    The contamination of radiotherapy room surfaces is significant and the measures of patient exposure rate are held on the fourth dependencies, relevant questions are raised: the background radiation of the room stay high due to surface contamination, may interfere with the rate of patient exposure at the time of its release? The monitoring site is important to determine whether the patient will be released? The value of the deal activity and the clinical condition of the patient may increase the contamination, influencing the monitoring results? This paper aims to conduct a quantitative analysis of surface contamination of the contribution of therapeutic room at the time is monitored exposure rate from inpatient. Measurements were made regarding the hospitalization of 32 patients with different doses administered activity, age and of both genders. The measurements were performed in the therapeutic rooms at the hospital Brotherhood Santa Casa de Misericordia de Sao Paulo. Exposure rate measurements were performed at the center of the room at 1 meter of the patient on the day of its release. After his release and prior to decontamination, measurements were performed at predetermined landmarks within the therapeutic room. The results revealed that on average background radiation, high due to surface contamination contributes only 2% of the patient dose rate. It can be considered that even with influence of contamination of surfaces, this is insignificant to determine if the patient may or may not be released. This study suggests that the site in which monitoring occurs exposure rate of the patient should not be decisive for liberation thereof. (author)

  17. Evaluation of the homogeneity of reference flat sources used in calibration of surface contamination monitors

    International Nuclear Information System (INIS)

    Silva Junior, I.A.; Xavier, M.; Siqueira, P.T.D.; Potiens, M.P.A.

    2014-01-01

    The aim of this study was to re-evaluate the uniformity of the wide area reference sources of the Calibration Laboratory of Instruments (LCI-IPEN) used in the calibration of surface contamination monitors, according the recommendations of the ISO 8769 standard and the NRPB. In this work used six wide area reference sources of 150 cm 2 of 241 Am, 14 C, 36 Cl, 137 Cs, 90 Sr+ 90 Y and 99 Tc with reference dates between 1996 and 1997 and three sources of 100 cm 2 of 14 C, 137 Cs and 60 Co were used with reference dates 2007. Measurements were performed with a radiation monitor of the Thermo, model FH40GX with a pancake probe, model FHZ732GM. We also made several models on paper with the objective of define each measurement position and an aluminum plate with a square hole (6.25 cm 2 ) in its center, allowing the passage of the radiation only through the hole. Each wide area reference source was positioned in setup and measurements were performed in order to cover the entire surface of the source. The values of the uniformity obtained partially confirm previous data obtained in another study conducted by LCI-IPEN, showing that some wide area reference sources 150 cm 2 in disagree with ISO 8769. In the former work, just the source of 241 Am (7.3%) was within the range specified by the standard, now have sources of 241 Am (5.7%), 137 Cs (8.8%), 90 Sr+ 9 '0Y (8, 8%) and 99 Tc (9.2%) with values within the specified uniformity. The sources of 14 C (53.3%) and 36 Cl (16.6%) were outside the specified. The wide area reference sources of 100 cm 2 , show disagreement in values of uniformity of the sources 14 C (46.7%) and 60 Co (10.4%). The values of the uniformity of the wide area reference sources show that some fonts can not be used in calibrations, because not in accordance with the value of uniformity specified in ISO 8769:2010, this is a conditions to believe a laboratory according to ISO 17025, show the laboratory performs its services with a high quality. The

  18. [Light reflection zone on the incisors' surface--a new parameter for smile esthetics evaluation].

    Science.gov (United States)

    Brezniak, N; Wasserstein, A; Shmuli, T

    2012-07-01

    The light reflection zone (LRZ) is a bright white dot or area that appears on the surface of the maxillary central incisors and/or the gingiva of the front teeth, visible in intra-oral and smile extra-oral photographs. Previously, a positive correlation between the location of the LRZ as observed in intra-oral frontal photographs and the inclination of the upper central incisors as measured on lateral headfims was found. The purpose of this study was to find whether this LRZ location can serve as a new parameter influencing the level of smile esthetics. Twelve pairs of facial photographs, including 10 of ordinary smiling persons and 2 of smiling models, were presented to 138 participants. The only difference between each pair was the location of the LRZ that was moved, compared to the original photograph, gingivally or incisally respectively, using Photoshop (Adobe). Each participant was asked to mark whether he/she noticed a difference between the 2 pictures, and if so, to score the nicer smile. Data analysis was carried out using Chi square test and Fisher's exact test (SPSS v17). The results showed that most of the participants did not recognize the differences between the pairs however, when differences were recognized, most of the participants pointed on the smile where the LRZ was located gingivally as the nicer one. This result was with statistical significance for the 2 models (p < 0.05), In conclusion, the LRZ is a new, yet unrecognized, parameter that can serve as a tool for the diagnosis of esthetic smile. The general population defines a nicer smile when the LRZ is located in the gingival area of the upper central incisors' surface rather than the incisal third. The LRZ should probably be studied not only in Orthodontics but also in other branches of dentistry.

  19. State-of-stress in magmatic rift zones: Predicting the role of surface and subsurface topography

    Science.gov (United States)

    Oliva, S. J. C.; Ebinger, C.; Rivalta, E.; Williams, C. A.

    2017-12-01

    Continental rift zones are segmented along their length by large fault systems that form in response to extensional stresses. Volcanoes and crustal magma chambers cause fundamental changes to the density structure, load the plates, and alter the state-of-stress within the crust, which then dictates fracture orientation. In this study, we develop geodynamic models scaled to a effects of loading on state-of-stress. By modeling varying geometric arrangements, and density contrasts of topographic and subsurface loads, and with reasonable regional extensional forces, the resulting state-of-stress reveals the favored orientation for new intrusions. Although our models are generalized, they allow us to evaluate whether a magmatic system (surface and subsurface) can explain the observed stress rotation, and enable new intrusions, new faults, or fault reactivation with orientations oblique to the main border faults. Our results will improve our understanding of the different factors at play in these extensional regimes, as well as contribute to a better assessment of the hazards in the area.

  20. A prospective survey of air and surface fungal contamination in a medical mycology laboratory at a tertiary care university hospital.

    Science.gov (United States)

    Sautour, Marc; Dalle, Frédéric; Olivieri, Claire; L'ollivier, Coralie; Enderlin, Emilie; Salome, Elsa; Chovelon, Isabelle; Vagner, Odile; Sixt, Nathalie; Fricker-Pap, Véronique; Aho, Serge; Fontaneau, Olivier; Cachia, Claire; Bonnin, Alain

    2009-04-01

    Invasive filamentous fungi infections resulting from inhalation of mold conidia pose a major threat in immunocompromised patients. The diagnosis is based on direct smears, cultural symptoms, and culturing fungi. Airborne conidia present in the laboratory environment may cause contamination of cultures, resulting in false-positive diagnosis. Baseline values of fungal contamination in a clinical mycology laboratory have not been determined to date. A 1-year prospective survey of air and surface contamination was conducted in a clinical mycology laboratory during a period when large construction projects were being conducted in the hospital. Air was sampled with a portable air system impactor, and surfaces were sampled with contact Sabouraud agar plates. The collected data allowed the elaboration of Shewhart graphic charts. Mean fungal loads ranged from 2.27 to 4.36 colony forming units (cfu)/m(3) in air and from 0.61 to 1.69 cfu/plate on surfaces. Strict control procedures may limit the level of fungal contamination in a clinical mycology laboratory even in the context of large construction projects at the hospital site. Our data and the resulting Shewhart graphic charts provide baseline values to use when monitoring for inappropriate variations of the fungal contamination in a mycology laboratory as part of a quality assurance program. This is critical to the appropriate management of the fungal risk in hematology, cancer and transplantation patients.

  1. Improving Satellite Retrieved Infrared Sea Surface Temperatures in Aerosol-Contaminated Regions

    Science.gov (United States)

    Luo, B.; Minnett, P. J.; Szczodrak, G.; Kilpatrick, K. A.

    2017-12-01

    Infrared satellite observations of sea surface temperature (SST) have become essential for many applications in meteorology, climatology, and oceanography. Applications often require high accuracy SST data: for climate research and monitoring an absolute uncertainty of 0.1K and stability of better than 0.04K per decade are required. Tropospheric aerosol concentrations increase infrared signal attenuation and prevent the retrieval of accurate satellite SST. We compare satellite-derived skin SST with measurements from the Marine-Atmospheric Emitted Radiance Interferometer (M-AERI) deployed on ships during the Aerosols and Ocean Science Expeditions (AEROSE) and with quality-controlled drifter temperatures. After match-up with in-situ SST and filtering of cloud contaminated data, the results indicate that SST retrieved from MODIS (Moderate Resolution Imaging Spectroradiometer) aboard the Terra and Aqua satellites have negative (cool) biases compared to shipboard radiometric measurements. There is also a pronounced negative bias in the Saharan outflow area that can introduce SST errors >1 K at aerosol optical depths > 0.5. In this study, we present a new method to derive night-time Saharan Dust Index (SDI) algorithms based on simulated brightness temperatures at infrared wavelengths of 3.9, 10.8 and 12.0 μm, derived using RTTOV. We derived correction coefficients for Aqua MODIS measurements by regression of the SST errors against the SDI. The biases and standard deviations are reduced by 0.25K and 0.19K after the SDI correction. The goal of this study is to understand better the characteristics and physical mechanisms of aerosol effects on satellite retrieved infrared SST, as well as to derive empirical formulae for improved accuracies in aerosol-contaminated regions.

  2. Definition of groundwater recharge and discharge zones through surface indicators: Centre-South of the Mesa Central, Mexico

    Directory of Open Access Journals (Sweden)

    Liliana Andrea Peñuela Arévalo

    2013-02-01

    Full Text Available The aim of this paper is the delimitation of groundwater recharge and discharge zones in the centresouth portion of the Mesa Central. This was achieved using groundwater flow systems theory, which has proved to be a valuable tool since it considers a systemic perspective of the environment, integrating several natural elements. There are various physical, chemical and biological processes generated in the subsoil within which groundwater is incorporated. This involvement is caused by the natural gravitational movement of groundwater which is manifested on the surface by contrasting evidences in the recharge and discharge zones. Therefore, the objective of this paper includes the demonstration of the usefulness of the analysis of those indicators to locate priority areas and also provides an approximation of groundwater functioning. The definition of recharge and discharge zones included the analysis of maps describing soil type, vegetation, topographic elevation, groundwater flowpath direction, springs, and presence of natural water bodies. Such analysis was carried out through the overlaying tool of ArcMap™ software. The results suggest that the highlands of Fría, San Miguelito and Santa Bárbara as recharge zones. Natural discharge zones were originally present in the plain of the Aguascalientes tectonic depression, and some flat and topographic low zones in the vicinity of Altos de Jalisco, Santa María del Río and Ojuelos.

  3. A Complete Analytical Screening Identifies the Real Pesticide Contamination of Surface Waters

    Science.gov (United States)

    Moschet, Christoph; Wittmer, Irene; Simovic, Jelena; Junghans, Marion; Singer, Heinz; Stamm, Christian; Leu, Christian; Hollender, Juliane

    2014-05-01

    A comprehensive assessment of pesticides in surface waters is challenging due to the large number of potential contaminants. In Switzerland for example, roughly 500 active ingredients are registered as either plant protection agent (PPA) or as biocide. In addition, an unlimited number of transformations products (TPs) can enter or be formed in surfaced waters. Most scientific publications or regulatory monitoring authorities have implemented 15-40 pesticides in their analytics. Only a few TPs are normally included. Interpretations of the surface water quality based on these subsets remains error prone. In the presented study, we carried out a nearly complete analytical screening covering 86% of all polar organic pesticides (from agricultural and urban sources) in Switzerland (300 substances) and 134 TPs with limits of quantification in the low ng/L range. The comprehensive pesticide screening was conducted by liquid-chromatography coupled to high-resolution tandem mass spectrometry. Five medium-sized rivers (Strahler stream order 3-4, catchment size 35-105 km2), containing high percentiles of diverse crops, orchards and urban settlements in their catchments, were sampled from March till July 2012. Nine subsequent time-proportional bi-weekly composite samples were taken in order to quantify average concentrations. In total, 104 different active ingredients could be detected in at least one of the five rivers. Thereby, 82 substances were only registered as PPA, 20 were registered as PPA and as biocide and 2 were only registered as biocide. Within the PPAs, herbicides had the most frequent detections and the highest concentrations, followed by fungicides and insecticides. Most concentrations were found between 1 and 50 ng/L; however 31 substances (mainly herbicides) had concentrations above 100 ng/L and 3 herbicides above 1000 ng/L. It has to be noted that the measured concentrations are average concentrations over two weeks in medium sized streams and that maximum

  4. Assessment of surface water pollutant models of estuaries and coastal zone of Quang Ninh – Hai Phong using Spot-5 images

    Directory of Open Access Journals (Sweden)

    Ke Luong Chinh

    2015-06-01

    Full Text Available The coastal zone and estuaries of Quang Ninh and Hai Phong have great potential not only for economic development but also for protection and conservation of biodiversity and ecosystem. Nowadays, due to industrial, agricultural and anthropogenic activities signs of water pollution in the region have been found. The level of surface water pollution can be determined by traditional methods through observatory stations. However, a traditional approach to determine water contamination is discontinuous, and thereby makes pollution assessment of the entire estuary very difficult. Nowadays, remote sensing technology has been developed and widely applied in many fields, for instance, in monitoring water environments. Remote sensing data combined with information from in-situ observations allow for extraction of polluted components in water and accurate measurements of pollution level in the large regions ensuring objectivity. According to results obtained from Spot-5 imagery of Quang Ninh and Hai Phong, the extracted pollution components, like BOD, COD and TSS can be determined with the root mean square error, the absolute mean error and the absolute mean percentage error (%: ±4.37 (mg/l 3.86 (mg/l, 27%; ±55.32 (mg/l, 48.30 (mg/l, 14%; and ±32.90 (mg/l, 23.38 (mg/l, 28%; respectively. Obtained outcomes guarantee objectivity in assessing water contaminant levels in the investigated regions and show the advantages of remote sensing applications in Resource and Environmental Monitoring in relation to Water – Air – Land.

  5. 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

  6. Integrated assessment of climate change impact on surface runoff contamination by pesticides.

    Science.gov (United States)

    Gagnon, Patrick; Sheedy, Claudia; Rousseau, Alain N; Bourgeois, Gaétan; Chouinard, Gérald

    2016-07-01

    Pesticide transport by surface runoff depends on climate, agricultural practices, topography, soil characteristics, crop type, and pest phenology. To accurately assess the impact of climate change, these factors must be accounted for in a single framework by integrating their interaction and uncertainty. This article presents the development and application of a framework to assess the impact of climate change on pesticide transport by surface runoff in southern Québec (Canada) for the 1981-2040 period. The crop enemies investigated were: weeds for corn (Zea mays); and for apple orchard (Malus pumila), 3 insect pests (codling moth [Cydia pomonella], plum curculio [Conotrachelus nenuphar], and apple maggot [Rhagoletis pomonella]), 2 diseases (apple scab [Venturia inaequalis], and fire blight [Erwinia amylovora]). A total of 23 climate simulations, 19 sites, and 11 active ingredients were considered. The relationship between climate and phenology was accounted for by bioclimatic models of the Computer Centre for Agricultural Pest Forecasting (CIPRA) software. Exported loads of pesticides were evaluated at the edge-of-field scale using the Pesticide Root Zone Model (PRZM), simulating both hydrology and chemical transport. A stochastic model was developed to account for PRZM parameter uncertainty. Results of this study indicate that for the 2011-2040 period, application dates would be advanced from 3 to 7 days on average with respect to the 1981-2010 period. However, the impact of climate change on maximum daily rainfall during the application window is not statistically significant, mainly due to the high variability of extreme rainfall events. Hence, for the studied sites and crop enemies considered, climate change impact on pesticide transported in surface runoff is not statistically significant throughout the 2011-2040 period. Integr Environ Assess Managem 2016;12:559-571. © Her Majesty the Queen in Right of Canada 2015; Published 2015 SETAC. © Her Majesty the

  7. Advancement of the arc-waterjet cutting to a gouging process for contaminated surface activity of steel components

    International Nuclear Information System (INIS)

    Bach, F.W.; Bruening, D.

    1990-01-01

    The technique of arc-waterjet cutting had to be progressed so that it is possible to gouge the surface of metallic components of nuclear power plants. With applicable cutting parameters depending on the thickness of the contamination the surface had to be gouged and converted to a granulation that is to remove. A continously pulled out wire electrode strikes an arc to the workpeace by short circuit and melts both. A concentric around the wire placed waterjet is able to wash the liquid metal away. With a computer numeric control it is possible to remove the surface of metal up to a deep penetration of 4 to 5 mm. With arc waterjet gouging a remote-controlled removal of contaminated surface activity in shutdowned nuclear power plants under water is possible. (orig./HP) With 15 refs., 1 tab., 14 figs [de

  8. Quantifying Organic Matter in Surface Waters of the United States and Delivery to the Coastal Zone

    Science.gov (United States)

    Boyer, E. W.; Alexander, R. B.; Smith, R. A.; Shih, J.

    2012-12-01

    Organic carbon (OC) is a critical water quality characteristic in surface waters. It is an important component of the energy balance and food chains in freshwater and estuarine aquatic ecosystems, is significant in the mobilization and transport of contaminants along flow paths, and is associated with the formation of known carcinogens in drinking water supplies. The importance of OC dynamics on water quality has been recognized, but challenges remain in quantitatively addressing processes controlling OC fluxes over broad spatial scales in a hydrological context, and considering upstream-downstream linkages along flow paths. Here, we: 1) quantified lateral OC fluxes in rivers, streams, and reservoirs across the nation from headwaters to the coasts; 2) partitioned how much organic carbon that is stored in lakes, rivers and streams comes from allochthonous sources (produced in the terrestrial landscape) versus autochthonous sources (produced in-stream by primary production); 3) estimated the delivery of dissolved and total forms of organic carbon to coastal estuaries and embayments; and 4) considered seasonal factors affecting the temporal variation in OC responses. To accomplish this, we developed national-scale models of organic carbon in U.S. surface waters using the spatially referenced regression on watersheds (SPARROW) technique. The modeling approach uses mechanistic formulations, imposes mass balance constraints, and provides a formal parameter estimation structure to statistically estimate sources and fate of OC in terrestrial and aquatic ecosystems. We calibrated and evaluated the model with statistical estimates of OC loads that were observed at a network of monitoring stations across the nation, and further explored factors controlling seasonal dynamics of OC based on these long term monitoring data. Our results illustrate spatial patterns and magnitudes OC loadings in rivers, highlighting hot spots and suggesting origins of the OC to each location

  9. The Critical Zone: A Necessary Framework for Understanding Surface Earth Processes

    Science.gov (United States)

    Dietrich, W. E.

    2016-12-01

    One definition of the critical zone is: the thin veneer of Earth that extends from the top of the vegetation to the base of weathered bedrock. With this definition we can envision the critical zone as a distinct entity with a well-defined top and a fairly well-defined bottom that is distributed across terrestrial earth landscapes. It is a zone of co-evolving processes and, importantly, much of this zone is well below the soil mantle (and commonly more than 10 times thicker than the soil). Weathering advance into fresh bedrock creates a hydrologically-conductive skin that mediates runoff and solute chemistry, stores water used by vegetation, releases water as baseflow to streams, influences soil production and hillslope evolution, and feeds gasses to the atmosphere. Especially in seasonally dry environments, rock moisture in the critical zone, i.e. moisture that is exchangeable and potentially mobile in the matrix and fractures of the bedrock, can be a significant source of water to plants and is a previously unrecognized large component of the water budget that matters to climate models. First observations on the systematic variation of the critical zone across hillslopes have led to four distinct theories representing four distinct processes for what controls the depth to fresh bedrock (and thus the thickness of this zone across a hillslope). These theories are motivating geophysical surveys, deep drilling, and other actions to parameterize and explore the power of these models. Studies at the NSF-supported Critical Zone Observatories have taught us that the critical zone is an entity and that enduring field studies reveal key processes. A challenge we now face is how to include this emerging understanding of the critical zone into models of reactive transport, hydrologic processes and water supply, critical zone structure, landscape evolution, and climate.

  10. Listeria monocytogenes contamination of the environment and surfaces of the equipment in the meat processing facilities in republic of Macedonia

    OpenAIRE

    Dean Jankuloski; Pavle Sekulovski; Risto Prodanov; Zehra Hajrulai Musliu; Biljana Stojanovska Dimzovska

    2007-01-01

    Listeria monocytogenes contamination of the environment and surfaces of the equipment was examined in seven meat processing facilities. Up to date prevalence of this foodborn pathogen in meat processing facilities facilities in Republic of Macedonia was unknown. Biofilms are composed from food spoilage microorganisms and food born pathogens. They are located on the surfaces of the equipment that come in contact with food and in facilities environment. Microorganisms in biofilm presenting micr...

  11. Cold plasma rapid decontamination of food contact surfaces contaminated with Salmonella and Escherichia coli 0157:H7

    Science.gov (United States)

    Cross-contamination of fresh produce from persistent pathogen reservoirs is a known risk factor in processing environments. Industry requires a waterless, zero-contact, chemical-free method for removing pathogens from food-contact surfaces. Cold plasma was tested for its ability to remove biofilms f...

  12. MECHANISTIC STUDIES OF SURFACE CATALYZED H2O2 DECOMPOSITION AND CONTAMINANT DEGRADATION IN THE PRESENCE OF SAND. (R823402)

    Science.gov (United States)

    This study examined the mechanism and kinetics of surface catalyzed hydrogen peroxide decomposition and degradation of contaminants in the presence of sand collected from an aquifer and a riverbed. Batch experiments were conducted using variable sand concentrations (0.2 to 1.0&nb...

  13. Bacterial communities of surface and deep hydrocarbon-contaminated waters of the Deepwater Horizon oil spill

    Science.gov (United States)

    Yang, T.; Nigro, L. M.; McKay, L.; Ziervogel, K.; Gutierrez, T.; Teske, A.

    2010-12-01

    We performed a 16S rRNA gene sequencing survey of bacterial communities within oil-contaminated surface water, deep hydrocarbon plume water, and deep water samples above and below the plume to determine spatial and temporal patterns of oil-degrading bacteria growing in response to the Deepwater Horizon oil leak. In addition, we are reporting 16S rRNA sequencing results from time series incubation, enrichment and cultivation experiments. Surface oil slick samples were collected 3 nautical miles from ground zero, (5/6/10, RV Pelican) and were added to uncontaminated surface water (collected within a 30 nautical mile radius of ground zero, 5/6/10 - 5/9/10, RV Pelican). This mixture was incubated for 20 days in a rolling bottle at 25°C. 16S rRNA clone libraries from marine snow-like microbial flocs that had formed during the incubation yielded a highly diverse bacterial community, predominately composed of the Alpha- and Gammaproteobacteria, and a smaller number of Planktomycetes and other bacterial lineages. The most frequently recovered proteobacterial sequences were closely related to cultured species of the genus Cycloclasticus, specialists in aerobic oxidation of aromatic hydrocarbons. These time series incubation results will be compared to the microbial community structure of contaminated surface water, sampled on the same cruise with RV Pelican (5/6/10-5/9/10) and frozen immediately. Stable isotope probing (SIP) experiments with C13-labelled alkanes and polycyclic aromatic substrates and gulf water samples have yielded different enrichments. With naphthalene, predominantly Alteromonas-related clones and a smaller share of Cycloclasticus clones were recovered; phenanthrene yielded predominantly clones related to Cycloclasticus, and diverse other Gamma- and Alphaproteobacteria. Analyses of SIP experiments with hexadecane are in progress. The microbial community composition of the deep hydrocarbon plume was characterized using water column profile samples taken

  14. In-situ active/passive bioreclamation of vadose zone soils contaminated with gasoline and waste oil using soil vapor extraction/bioventing: Laboratory pilot study to full scale site operation

    International Nuclear Information System (INIS)

    Zachary, S.P.; Everett, L.G.

    1993-01-01

    The use of soil venting to supply oxygen and remove metabolites from the biodegradation of light hydrocarbons is a cost effective in-situ remediation approach. To date, little data exists on the effective in-situ bioreclamation of vadose zone soil contaminated with waste/hydraulic oil without excavation or the addition of water or nutrients to degrade the heavy petroleum contaminants. Gasoline and waste/hydraulic oil contaminated soils below an active commercial building required an in-situ non-disruptive remediation approach. Initial soil vapor samples collected from the vadose zone revealed CO 2 concentrations in excess of 16% and O 2 concentrations of less than 1% by volume. Soil samples were collected from below the building within the contaminated vadose zone for laboratory chemical and physical analysis as well as to conduct a laboratory biotreatability study. The laboratory biotreatability study was conducted for 30 days to simulate vadose zone bioventing conditions using soil taken from the contaminated vadose zone. Results of the biotreatability study revealed that the waste oil concentrations had been reduced from 960 mg/Kg to non-detectable concentrations within 30 days and the volatile hydrocarbon content had decreased exponentially to less than 0.1% of the original concentration. Post treatability study biological enumeration revealed an increase in the microbial population of two orders of magnitude

  15. Soil-gas helium and surface-waves detection of fault zones in ...

    Indian Academy of Sciences (India)

    in southern India, for the detection of fracture and fault zones in a granite basement terrain having ... groundwater resource zone in hard rock terrains. A significant ..... 51 121–129. Xu C and Butt S D 2006 Evaluation of MASW techniques to image steeply dipping cavities in laterally inhomogeneous terrain; J. Appl. Geophys.

  16. 22-year surface salinity changes in the Seasonal Ice Zone near 140°E off Antarctica

    Science.gov (United States)

    Morrow, Rosemary; Kestenare, Elodie

    2017-11-01

    Seasonal and interannual variations in sea surface salinity (SSS) are analyzed in the Sea Ice Zone south of 60°S, from a 22-year time series of observations near 140°E. In the northern sea-ice zone during the warming, melting cycle from October to March, waters warm by an average of 3.5 °C and become fresher by 0.1 to 0.25. In the southern sea-ice zone, the surface temperatures vary from - 1 to 1 °C over summer, and the maximal SSS range occurs in December, with a minimum SSS of 33.65 near the Southern Boundary of the ACC, reaching 34.4 in the shelf waters close to the coast. The main fronts, normally defined at subsurface, are shown to have more distinct seasonal characteristics in SSS than in SST. The interannual variations in SSS are more closely linked to variations in upstream sea-ice cover than surface forcing. SSS and sea-ice variations show distinct phases, with large biannual variations in the early 1990s, weaker variations in the 2000s and larger variations again from 2009 onwards. The calving of the Mertz Glacier Tongue in February 2010 leads to increased sea-ice cover and widespread freshening of the surface layers from 2011 onwards. Summer freshening in the northern sea-ice zone is 0.05-0.07 per decade, increasing to 0.08 per decade in the southern sea-ice zone, largely influenced by the Mertz Glacier calving event at the end of our time series. The summer time series of SSS on the shelf at 140°E is in phase but less variable than the SSS observed upstream in the Adélie Depression, and thus represents a spatially integrated index of the wider SSS variations.

  17. Near-surface versus fault zone damage following the 1999 Chi-Chi earthquake: Observation and simulation of repeating earthquakes

    Science.gov (United States)

    Chen, Kate Huihsuan; Furumura, Takashi; Rubinstein, Justin L.

    2015-01-01

    We observe crustal damage and its subsequent recovery caused by the 1999 M7.6 Chi-Chi earthquake in central Taiwan. Analysis of repeating earthquakes in Hualien region, ~70 km east of the Chi-Chi earthquake, shows a remarkable change in wave propagation beginning in the year 2000, revealing damage within the fault zone and distributed across the near surface. We use moving window cross correlation to identify a dramatic decrease in the waveform similarity and delays in the S wave coda. The maximum delay is up to 59 ms, corresponding to a 7.6% velocity decrease averaged over the wave propagation path. The waveform changes on either side of the fault are distinct. They occur in different parts of the waveforms, affect different frequencies, and the size of the velocity reductions is different. Using a finite difference method, we simulate the effect of postseismic changes in the wavefield by introducing S wave velocity anomaly in the fault zone and near the surface. The models that best fit the observations point to pervasive damage in the near surface and deep, along-fault damage at the time of the Chi-Chi earthquake. The footwall stations show the combined effect of near-surface and the fault zone damage, where the velocity reduction (2–7%) is twofold to threefold greater than the fault zone damage observed in the hanging wall stations. The physical models obtained here allow us to monitor the temporal evolution and recovering process of the Chi-Chi fault zone damage.

  18. Sequestration of Sr-90 Subsurface Contamination in the Hanford 100-N Area by Surface Infiltration of a Ca-Citrate-Phosphate Solution

    Energy Technology Data Exchange (ETDEWEB)

    Szecsody, James E.; Rockhold, Mark L.; Oostrom, Martinus; Moore, R. C.; Burns, Carolyn A.; Williams, Mark D.; Zhong, Lirong; Fruchter, Jonathan S.; McKinley, James P.; Vermeul, Vincent R.; Covert, Matthew A.; Wietsma, Thomas W.; Breshears, Andrew T.; Garcia, Ben J.

    2009-03-01

    The objective of this project is to develop a method to emplace apatite precipitate in the 100N vadose zone, which results in sorption and ultimately incorporation of Sr-90 into the apatite structure. The Ca-citrate-PO4 solution can be infiltrated into unsaturated sediments to result in apatite precipitate to provide effective treatment of Sr-90 contamination. Microbial redistribution during solution infiltration and a high rate of citrate biodegradation for river water microbes (water used for solution infiltration) results in a relatively even spatial distribution of the citrate biodegradation rate and ultimately apatite precipitate in the sediment. Manipulation of the Ca-citrate-PO4 solution infiltration strategy can be used to result in apatite precipitate in the lower half of the vadose zone (where most of the Sr-90 is located) and within low-K layers (which are hypothesized to have higher Sr-90 concentrations). The most effective infiltration strategy to precipitate apatite at depth (and with sufficient lateral spread) was to infiltrate a high concentration solution (6 mM Ca, 15 mM citrate, 60 mM PO4) at a rapid rate (near ponded conditions), followed by rapid, then slow water infiltration. Repeated infiltration events, with sufficient time between events to allow water drainage in the sediment profile can be used to buildup the mass of apatite precipitate at greater depth. Low-K heterogeneities were effectively treated, as the higher residual water content maintained in these zones resulted in higher apatite precipitate concentration. High-K zones did not receive sufficient treatment by infiltration, although an alternative strategy of air/surfactant (foam) was demonstrated effective for targeting high-K zones. The flow rate manipulation used in this study to treat specific depths and heterogeneities are not as easy to implement at field scale due to the lack of characterization of heterogeneities and difficulty tracking the wetting front over a large

  19. Statistical mapping of zones of focused groundwater/surface-water exchange using fiber-optic distributed temperature sensing

    Science.gov (United States)

    Mwakanyamale, Kisa; Day-Lewis, Frederick D.; Slater, Lee D.

    2013-01-01

    Fiber-optic distributed temperature sensing (FO-DTS) increasingly is used to map zones of focused groundwater/surface-water exchange (GWSWE). Previous studies of GWSWE using FO-DTS involved identification of zones of focused GWSWE based on arbitrary cutoffs of FO-DTS time-series statistics (e.g., variance, cross-correlation between temperature and stage, or spectral power). New approaches are needed to extract more quantitative information from large, complex FO-DTS data sets while concurrently providing an assessment of uncertainty associated with mapping zones of focused GSWSE. Toward this end, we present a strategy combining discriminant analysis (DA) and spectral analysis (SA). We demonstrate the approach using field experimental data from a reach of the Columbia River adjacent to the Hanford 300 Area site. Results of the combined SA/DA approach are shown to be superior to previous results from qualitative interpretation of FO-DTS spectra alone.

  20. Effects of the Chernobyl accident on radioactive contamination of groundwater utilized for water supply

    International Nuclear Information System (INIS)

    Bugai, D.A.; Shestopalov, V.M.; Rudenko, Y.F.; Onischenko, I.P.; Gudzenko, I.P.; Bublyas, V.N.

    1997-01-01

    According to the notions of classic hydrogeology, the groundwaters of deep-laying aquifers were considered to be safely protected against various external contaminants, due to high sorption properties of aeration zone soils, regional distribution of aquitards, and very long periods of ground water formation. Contamination of upper subsurface aquifer and a part of artesian aquifers is exclusively significant in Chernobyl exclusion zone characterized by high levels of surface contamination with radionuclides

  1. Effect of electrocardiographic contamination on surface electromyography assessment of back muscles.

    Science.gov (United States)

    Hu, Yong; Mak, Joseph N F; Luk, Keith D K

    2009-02-01

    The purpose of this study was to demonstrate the relative effect of electrocardiography (ECG) on back muscle surface electromyography (SEMG) parameters and their corresponding sensitivity in low back pain (LBP) assessment. Back muscle SEMG activities were recorded from 17 healthy subjects and 18 chronic LBP patients under static postures (straight sitting and upright standing), and dynamic action (flexion-extension). ECG cancellation based on independent component analysis (ICA) method was performed. Root mean square (RMS) and median frequency (MF) of raw and denoised SEMG data were computed respectively. Multiple comparisons were then performed. A consistent trend of change (increased MF and decreased RMS) followed ECG removal was noticed. In particular, in SEMG measurements under static postures, a significant decrease in RMS (pcorruption by ECG artifacts on SEMG measurements was found to be more serious and prominent in static postures than that in dynamic action. After ECG removal, significant improvements in the ability of SEMG to discriminate LBP patients from healthy subjects were seen in RMS amplitude recorded while standing (peffect of ECG contamination on back muscles SEMG parameters and LBP assessment.

  2. SCO shipments from Rocky Flats - Experience and current practice [Surface Contaminated Object

    International Nuclear Information System (INIS)

    Bracken, Gary; Morris, Robert L.

    2001-01-01

    Decommissioning activities at Rocky Flats Environmental Technology Site (RFETS) are expected to generate approximately 251,000 cubic meters of low-level radioactive waste. Almost half of this will be characterized and shipped as the Department of Transportation ''Surface Contaminated Object'' (SCO) shipping class. In the 2 years since an SCO characterization method was implemented, almost 11,000 of the 18,000 cubic meters of low-level waste were SCO. RFETS experience to-date using an SCO waste characterization method has shown significant time and cost savings, reduced errors, and enhanced employee safety. SCO waste is characterized prior to packaging, near the point of generation, by any of the site's 300 Radiological Control Technicians using inexpensive radiological control survey instruments. This reduces on-site waste container moves and eliminates radiometric analysis at centrally located drum or crate counters. Containers too large for crate counters can also be characterized. Current instrumentation is not adequate to take full advantage of the SCO regulations. Future improvements in the SCO characterization and shipping process are focused on use of larger and/or reusable containers, extended-range instruments, and additional statistical methods, so that the full extent of the SCO regulations can be used

  3. Cuban-Brazilian comparison of the calibration procedures for surface contamination monitors

    International Nuclear Information System (INIS)

    Salas, Gonzalo W.; Garcia, Jose A.T.; Ramos, Manoel M.O.

    2007-01-01

    The calibration laboratory of the CPHR, Centro de Proteccion e Higiene de las Radiaciones, is the only laboratory that performs calibrations of radiation protection instruments in Cuba. Recently they started a cooperation project with IAEA, code number CUB3002-01 with the task title 'Assuring and Demonstrating the safety of radioactive Waste Management'. Within the frame of this project they have a compromise to implement the calibration service for surface contamination monitors, for which they received instruments and sources. In 2006 the Laboratorio Nacional de Metrologia das Radiacoes Ionizantes (LNMRI) from the Instituto de Radioprotecao e Dosimetria, IRD/CNEN, was invited to perform a mission to CPHR in order to evaluate the level of implementation of the service trough the insertion of the service in the Quality Assurance System of their laboratory, and perform a comparison exercise to test the calibration method implemented. The results were evaluated by the methodology recommended in the ISO/IEC 43-1 standard. These results show that all values from both laboratories are comparable for most radionuclides except for Cl-36. The preliminary investigation about this situation is presented in the paper. (author)

  4. Strippable core-shell polymer emulsion for decontamination of radioactive surface contamination

    International Nuclear Information System (INIS)

    Hwang, Ho-Sang; Seo, Bum-Kyoung; Lee, Kune-Woo

    2011-01-01

    In this study, the core-shell composite polymer for decontamination from the surface contamination was synthesized by the method of emulsion polymerization and blends of polymers. The strippable polymer emulsion is composed of the poly(styrene-ethyl acrylate) [poly(St-EA)] composite polymer, poly(vinyl alcohol) (PVA) and polyvinylpyrrolidone (PVP). The morphology of the poly(St-EA) composite emulsion particle was core-shell structure, with polystyrene (PS) as the core and poly(ethyl acrylate) (PEA) as the shell. Core-shell polymers of styrene (St)/ethyl acrylate (EA) pair were prepared by sequential emulsion polymerization in the presence of sodium dodecyl sulfate (SDS) as an emulsifier using ammonium persulfate (APS) as an initiator. Related tests and analysis confirmed the success in synthesis of composite polymer. The products are characterized by FT-IR spectroscopy, TGA that were used, respectively, to show the structure, the thermal stability of the prepared polymer. Two-phase particles with a core-shell structure were obtained in experiments where the estimated glass transition temperature and the morphologies of emulsion particles. Decontamination factors of the strippable polymeric emulsion were evaluated with the polymer blend contents. (author)

  5. HYDROLASING OF CONTAMINATED UNDERWATER BASIN SURFACES AT THE HANFORD K AREA

    International Nuclear Information System (INIS)

    CHRONISTER, G.B.

    2005-01-01

    This paper discusses selecting and implementing hydrolasing technology to reduce radioactive contamination in preparing to dispose of the K Basins; two highly contaminated concrete basins at the Hanford Site. A large collection of spent nuclear fuel stored for many years underwater at the K Basins has been removed to stable, dry, safe storage. Remediation activities have begun for the remaining highly contaminated water. sludge, and concrete basin structures. Hydrolasing will be used to decontaminate and prepare the basin structures for disposal

  6. Do Contaminants Originating from State-of-the-Art Treated Wastewater Impact the Ecological Quality of Surface Waters?

    Science.gov (United States)

    Stalter, Daniel; Magdeburg, Axel; Quednow, Kristin; Botzat, Alexandra; Oehlmann, Jörg

    2013-01-01

    Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0–100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this

  7. Defining an Abrasion Index for Lunar Surface Systems as a Function of Dust Interaction Modes and Variable Concentration Zones

    Science.gov (United States)

    Kobrick, Ryan L.; Klaus, David M.; Street, Kenneth W., Jr.

    2010-01-01

    Unexpected issues were encountered during the Apollo era of lunar exploration due to detrimental abrasion of materials upon exposure to the fine-grained, irregular shaped dust on the surface of the Moon. For critical design features involving contact with the lunar surface and for astronaut safety concerns, operational concepts and dust tolerance must be considered in the early phases of mission planning. To systematically define material selection criteria, dust interaction can be characterized by two-body or three-body abrasion testing, and subcategorically by physical interactions of compression, rolling, sliding and bending representing specific applications within the system. Two-body abrasion occurs when a single particle or asperity slides across a given surface removing or displacing material. Three-body abrasion occurs when multiple particles interact with a solid surface, or in between two surfaces, allowing the abrasives to freely rotate and interact with the material(s), leading to removal or displacement of mass. Different modes of interaction are described in this paper along with corresponding types of tests that can be utilized to evaluate each configuration. In addition to differential modes of abrasion, variable concentrations of dust in different zones can also be considered for a given system design and operational protocol. These zones include: (1) outside the habitat where extensive dust exposure occurs, (2) in a transitional zone such as an airlock or suitport, and (3) inside the habitat or spacesuit with a low particle count. These zones can be used to help define dust interaction frequencies, and corresponding risks to the systems and/or crew can be addressed by appropriate mitigation strategies. An abrasion index is introduced that includes the level of risk, R, the hardness of the mineralogy, H, the severity of the abrasion mode, S, and the frequency of particle interactions, F.

  8. Radionuclide transport from near-surface repository for radioactive waste - The unsaturated zone approach

    Energy Technology Data Exchange (ETDEWEB)

    Jakimaviciute-Maseliene, V. [Vilnius University (Lithuania); Mazeika, J. [Nature Research Centre (Lithuania); Motiejunas, S. [Radioactive Waste Management Agency (Lithuania)

    2014-07-01

    About 100 000 m{sup 3} of solid conditioned Low and Intermediate Level Waste (LILW), generated during operation and decommissioning of the Ignalina nuclear power plant (INPP), are to be disposed of in a near-surface repository (NSR) - a 'hill'-type repository with reinforced concrete vaults and with engineered and natural barriers. The northeastern Lithuania and the environment of the INPP in particular were recognized as the areas most suitable for a near-surface repository (Stabatiske Site). The engineered barriers of the repository consist of concrete cells surrounded by clay-based material of low permeability with about the same isolating capacity in all directions. The clay materials must be effectively compactable so that required hydraulic conductivity is reached. The Lithuanian Triassic clay turned out to be sufficiently rich in smectites and was proposed as main candidate for sealing of the repository. When the concrete vaults are filled, the repository cover will be constructed. The surface of the mound will be planted with grass. In this study a computer code FEFLOW 5.0 was applied for simulating the transport of the most mobile radionuclides ({sup 3}H, {sup 14}C, {sup 59}Ni and {sup 94}Nb) with moisture through an unsaturated vault of the near-surface repository in Stabatiske Site. The HYDRUS-1D analysis was used to assess the radionuclide transport in the repository and to estimate initial activity concentrations of radionuclides transported from the cemented waste matrix. Radionuclide release from the vault in the unsaturated conditions after closure of the repository and consequent contaminant plume transport has been assessed taking into account site-specific natural and engineering conditions and based on a normal evolution scenario. The highest peak radionuclide activity concentrations were estimated applying the FEFLOW code. The highest value of {sup 14}C activity concentration(about 1.3x10{sup 8} Bq/m{sup 3}) at the groundwater table

  9. ZVI-Clay remediation of a chlorinated solvent source zone, Skuldelev, Denmark: 1. Site description and contaminant source mass reduction

    DEFF Research Database (Denmark)

    Fjordbøge, Annika Sidelmann; Riis, Charlotte; Christensen, Anders G.

    2012-01-01

    -order degradation half-life of 47days resulting in more than 99% depletion of the source mass after one year. The main degradation product was ethene, while only low concentrations of the primarily biotic sequential degradation products (cDCE, VC) were detected. The soil mixing resulted in more homogeneous vertical......Field investigations on the effects of ZVI-Clay soil mixing were conducted at a small DNAPL source zone with PCE as the parent compound. In a one-year monitoring program, soil samples were collected at three horizontal sampling planes (2.5, 5.0 and 7.5m bgs.). PCE was found to have a pseudo first...... source zones with ZVI-Clay soil mixing....

  10. Effect of surface carbon contamination on the chemical states of N-doped ZnO thin films

    Science.gov (United States)

    Zhang, Hong; Li, Wanjun; Qin, Guoping; Fang, Liang; Ruan, Haibo; Tan, Mi; Wu, Fang; Kong, Chunyang

    2018-02-01

    Nitrogen-doped ZnO thin films [ZnO:N] and intentional surface carbon-contaminated ZnO:N thin films [ZnO:N@C] were grown on quartz substrates by radio frequency magnetron sputtering deposition method. The structural, electrical and optical properties as well as chemical states of elements were investigated by means of X-ray diffraction (XRD), Hall effect measurement (Hall), UV-Vis-Near infrared spectrophotometer and X-ray photoelectron spectroscopy (XPS). The results indicate that surface carbon contamination almost does not affect the band gap of ZnO:N thin films but has a strong impact on the crystal quality of ZnO:N thin film surface and results in a significant increase in tensile stress. The XPS analysis shows that the effect of surface carbon contamination treatment on the chemical states of ZnO:N thin films is remarkable. Because the stability of Zn-N bonds in N-rich local environments is nowhere near that of those in O-rich local environments, the N atoms in N-rich local environments easily bond with surface carbon atoms to form undesirable C-N bonds, thus resulting in a decrease of NO acceptors in N-rich local environments. Obviously, it is unfavorable to subsequently prepare high stability of N-doped p-type ZnO thin films.

  11. Surface Tension Estimates for Droplet Formation in Slurries with Low Concentrations of Hydrophobic Particles, Polymer Flocculants or Surface-Active Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Gauglitz, Phillip A.; Mahoney, Lenna A.; Blanchard, Jeremy; Bamberger, Judith A.

    2011-06-10

    In support of the K-Basin project, Pacific Northwest National Laboratory (PNNL) was requested to evaluate the appropriate surface tension value to use in models predicting the formation of droplets from spray leaks of K-Basin slurries. The specific issue was whether it was more appropriate to use the surface tension of pure water in model predictions for all plausible spray leaks or to use a lower value. The surface tension of K-Basin slurries is potentially affected not only by particles but by low concentrations of nonionic polyacrylamide flocculant and perhaps by contaminants with surfactant properties, which could decrease the surface tension below that of water. A lower surface tension value typically results in smaller droplets being formed with a larger fraction of droplets in the respirable size range, so using the higher surface tension value of pure water is not conservative and thus needs a strong technical basis.

  12. SUBSTANTIATION OF THE CONCEPT OF TRANSFER TO CONDITIONS OF NORMAL POPULATION ACTIVITY OF THE SETTLEMENTS CONSIDERED TO BE ZONES OF RADIOACTIVE CONTAMINATION AFTER THE CHERNOBYL NPP ACCIDENT

    Directory of Open Access Journals (Sweden)

    I. K. Romanovich

    2016-01-01

    Full Text Available The article contains substantiation of criteria of return of territories with radioactive pollution caused by Chernobyl NPP accident to conditions of normal population activity. It is established that in 12 entities of the Russian Federation (except Bryansk and Kaluga regions all agricultural food produce, including that from the personal part-time farms, corresponds to hygienic specifications. Non- corresponding to the standard SanPiN 2.3.2.1078-01 on 137Cs are part of the milk samples produced at personal part-time farms of the Bryansk region and most of natural foodstuff samples (berries, mushrooms, fish and wild animals meat in Bryansk and Kaluga regions. The content of 137Cs both in agricultural and in wild-growing foodstuff produced at radioactively contaminated territories depends not only on the density of radioactive pollution, but also on the types of soil. The average settlement annual effective dose of population irradiation (AAED90 in the 3700 among 4413 settlements as of 2014 was below 0.3 mSv/year. Only in 713 settlements of Bryansk, Kaluga, Oryol and Tula regions the AAED90 exceeds 0.3 mSv/year. In the Bryansk region, once subject to the greatest radioactive contamination, in 276 settlements AAED90 exceeds 1 mSv/year, and in 8 of them - 5 mSv/year.The legislation of the Russian Federation defines only criteria and requirements for consideration of the suffered territories as zones of radioactive contamination. Requirements on transfer of territories polluted by radiation accidents and their population to normal life activity conditions (regarding the radiological factor are not developed.Radiological criteria are suggested for transfer of the settlements considered to be the zone of radioactive pollution to conditions of normal life activity: average irradiation dose of critical population group: 1.0 mSv per year and lower (AAED crit; decrease of radionuclide soil contamination density to the level enabling to use the territory

  13. Klebsiella sp. FIRD 2, a TBT-resistant bacterium isolated from contaminated surface sediment along Strait of Johor Malaysia.

    Science.gov (United States)

    Abubakar, Abdussamad; Mustafa, Muskhazli B; Johari, Wan Lutfi Wan; Zulkifli, Syaizwan Zahmir; Ismail, Ahmad; Mohamat-Yusuff, Ferdaus Binti

    2015-12-15

    A possible tributyltin (TBT)-degrading bacterium isolated from contaminated surface sediment was successfully identified as Klebsiella sp. FIRD 2. It was found to be the best isolate capable of resisting TBT at a concentration of 1000 μg L(-1). This was a concentration above the reported contaminated level at the sampling station, 790 μg L(-1). Further studies revealed that the isolate was Gram negative and resisted TBT concentrations of up to 1500 μg L(-1) in a Minimal Salt Broth without the addition of any carbon source within the first 48 h of incubation. It is expected that additional work could be conducted to check the degradation activity of this new isolate and possibly improve the degradation capacity in order to contribute to finding a safe and sustainable remediation solution of TBT contamination. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Radiation contamination monitors

    International Nuclear Information System (INIS)

    Kato, Tsutomu; Iba, Hiroshi; Sato, Hiroshi

    1999-01-01

    To make sure of no contamination on people, used articles and working uniforms coming out of the radiation controlled area, nuclear power plants are equipped with radioactive contamination monitors. This paper outlines the basic specifications and advantages of our personnel surface contamination monitors to inspect whole-body surface contamination of people coming out, article surface contamination monitors to inspect the surface and inside contamination of used articles brought out, laundry monitors to inspect surface contamination of working uniforms used in the area before and after a wash, and whole-body counters to inspect and measure the internal contamination of a person out of the area. (author)

  15. The influence of surface contamination on the ion emission from nanosecond-pulsed laser ablation of Al and Cu

    Science.gov (United States)

    Ullah, S.; Dogar, A. H.; Qayyum, H.; Rehman, Z. U.; Qayyum, A.

    2018-04-01

    Ions emitted from planar Al and Cu targets irradiated with a 1064 nm pulsed laser were investigated with the help of a time-resolving Langmuir probe. It was found that the intensity of the ions emitted from a target area rapidly decreases with the increasing number of laser shots, and seems to reach saturation after about 10 laser shots. The saturated intensity of Al and Cu ions was approximately 0.1 and 0.3 times the intensity of the respective ions measured at the first laser shot, respectively. The higher target ion intensity for the first few shots is thought to be due to the enhanced ionization of target atoms by vacuum-ultraviolet radiations emitted from the thermally excited/ionized surface contaminants. The reduction of target ion intensity with an increasing number of laser shots thus indicates the removal of contaminants from the irradiated surface area. Laser-cleaned Al and Cu surfaces were then allowed to be recontaminated with residual vacuum gases and the ion intensity was measured at various time delays. The prolonged exposure of the cleaned target to vacuum residual gases completely restores the ion intensity. Regarding surface contaminants removal, laser shots of higher intensities were found to be more effective than a higher number of laser shots having lower intensities.

  16. Contamination of rural surface and ground water by endosulfan in farming areas of the Western Cape, South Africa

    Directory of Open Access Journals (Sweden)

    London Leslie

    2003-03-01

    Full Text Available Abstract Background In South Africa there is little data on environmental pollution of rural water sources by agrochemicals. Methods This study investigated pesticide contamination of ground and surface water in three intensive agricultural areas in the Western Cape: the Hex River Valley, Grabouw and Piketberg. Monitoring for endosulfan and chlorpyrifos at low levels was conducted as well as screening for other pesticides. Results The quantification limit for endosulfan was 0.1 μg/L. Endosulfan was found to be widespread in ground water, surface water and drinking water. The contamination was mostly at low levels, but regularly exceeded the European Drinking Water Standard of 0.1 μg/L. The two most contaminated sites were a sub-surface drain in the Hex River Valley and a dam in Grabouw, with 0.83 ± 1.0 μg/L (n = 21 and 3.16 ± 3.5 μg/L (n = 13 average endosulfan levels respectively. Other pesticides including chlorpyrifos, azinphos-methyl, fenarimol, iprodione, deltamethrin, penconazole and prothiofos were detected. Endosulfan was most frequently detected in Grabouw (69% followed by Hex River (46% and Piketberg (39%. Detections were more frequent in surface water (47% than in groundwater (32% and coincided with irrigation, and to a lesser extent, to spraying and trigger rains. Total dietary endosulfan intake calculated from levels found in drinking water did not exceed the Joint WHO/FAO Meeting on Pesticide Residues (JMPR criteria. Conclusion The study has shown the need for monitoring of pesticide contamination in surface and groundwater, and the development of drinking water quality standards for specific pesticides in South Africa.

  17. Contaminants in groundwater: Chemical processes

    International Nuclear Information System (INIS)

    Cherry, J.A.; Gillham, R.W.; Barker, J.F.

    1984-01-01

    The movement of most toxic contaminants in groundwater is affected by chemical reactions that cause transfer of contaminant mass between the liquid and solid phases or conversion of dissolved species from one form to another. The chemical attenuation of inorganic contaminants occurs mainly by adsorption, precipitation, oxidation, or reduction. organic contaminants can be adsorbed or degraded by microbiological processes, but at present little is known about their behavior, particularly under the anaerobic conditions that are common in contaminated groundwater. Field and laboratory studies have established that various toxic heavy metals, transition metals, metalloids, radionuclides, and other inorganic species can be mobile or immobile in the groundwater zone, depending on the hydrogeochemical conditions represented by the pH, the redox condition, the ionic strength, the mineralogy, the solid-phase surface area, and the complexing capacity. Although the importance of chemical reactions in the attenuation of contaminants is widely recognized, the capabilities for attenuation predictions are not well developed. This is the case because the chemical processes within dynamic groundwater systems are complex; consequently, many of the geochemical parameters in predictive models are problematic. The prediction problem is complicated by the fact that the chemical processes are continually influenced by the redistribution of dissolved species caused by molecular diffusion and mechanical dispersion. The complexities of these mixing processes contribute to the difficulties in developing reliable methods for predicting the chemical behavior of contaminants in the groundwater zone

  18. Dynamic Linkages Between the Transition Zone & Surface Plate Motions in 2D Models of Subduction

    Science.gov (United States)

    Arredondo, K.; Billen, M. I.

    2013-12-01

    While slab pull is considered the dominant force controlling plate motion and speed, its magnitude is controlled by slab behavior in the mantle, where tomographic studies show a wide range of possibilities from direct penetration to folding, or stagnation directly above the lower mantle (e.g. Fukao et al., 2009). Geodynamic studies have investigated various parameters, such as plate age and two phase transitions, to recreate observed behavior (e.g. Běhounková and Cízková, 2008). However, past geodynamic models have left out known slab characteristics that may have a large impact on slab behavior and our understanding of subduction processes. Mineral experiments and seismic observations have indicated the existence of additional phase transitions in the mantle transition zone that may produce buoyancy forces large enough to affect the descent of a subducting slab (e.g. Ricard et al., 2005). The current study systematically tests different common assumptions used in geodynamic models: kinematic versus free-slip boundary conditions, the effects of adiabatic heating, viscous dissipation and latent heat, compositional layering and a more complete suite of phase transitions. Final models have a complete energy equation, with eclogite, harzburgite and pyrolite lithosphere compositional layers, and seven composition-dependent phase transitions within the olivine, pyroxene and garnet polymorph minerals. Results show important feedback loops between different assumptions and new behavior from the most complete models. Kinematic models show slab weakening or breaking above the 660 km boundary and between compositional layers. The behavior in dynamic models with a free-moving trench and overriding plate is compared to the more commonly found kinematic models. The new behavior may have important implications for the depth distribution of deep earthquakes within the slab. Though the thermodynamic parameters of certain phase transitions may be uncertain, their presence and

  19. Hydrogeology, Water Chemistry, and Factors Affecting the Transport of Contaminants in the Zone of Contribution of a Public-Supply Well in Modesto, Eastern San Joaquin Valley, California

    Science.gov (United States)

    Jurgens, Bryant C.; Burow, Karen R.; Dalgish, Barbara A.; Shelton, Jennifer L.

    2008-01-01

    Ground-water chemistry in the zone of contribution of a public-supply well in Modesto, California, was studied by the U.S. Geological Survey National Water Quality Assessment (NAWQA) Program's topical team for Transport of Anthropogenic and Natural Contaminants (TANC) to supply wells. Twenty-three monitoring wells were installed in Modesto to record baseline hydraulic information and to collect water-quality samples. The monitoring wells were divided into four categories that represent the chemistry of different depths and volumes of the aquifer: (1) water-table wells were screened between 8.5 and 11.7 m (meter) (28 and 38.5 ft [foot]) below land surface (bls) and were within 5 m (16 ft) of the water table; (2) shallow wells were screened between 29 and 35 m (95 and 115 ft) bls; (3) intermediate wells were screened between 50.6 and 65.5 m (166 and 215 ft) bls; and (4) deep wells are screened between 100 to 106 m (328 and 348 ft) bls. Inorganic, organic, isotope, and age-dating tracers were used to characterize the geochemical conditions in the aquifer and understand the mechanisms of mobilization and movement of selected constituents from source areas to a public-supply well. The ground-water system within the study area has been significantly altered by human activities. Water levels in monitoring wells indicated that horizontal movement of ground water was generally from the agricultural areas in the northeast towards a regional water-level depression within the city in the southwest. However, intensive pumping and irrigation recharge in the study area has caused large quantities of ground water to move vertically downward within the regional and local flow systems. Analysis of age tracers indicated that ground-water age varied from recent recharge at the water table to more than 1,000 years in the deep part of the aquifer. The mean age of shallow ground water was determined to be between 30 and 40 years. Intermediate ground water was determined to be a mixture

  20. Contamination by persistent toxic substances in surface sediment of urban rivers in Chaohu City, China.

    Science.gov (United States)

    Li, Feipeng; Zhang, Haiping; Meng, Xiangzhou; Chen, Ling; Yin, Daqiang

    2012-01-01

    The concentration and spatial distribution of persistent toxic substances (PTS) in the river sediment in Chaohu City, China were investigated. A total of nine surface sediments were collected and the selected PTS pollutants including six heavy metals and nineteen polybrominated diphenyl ethers (PBDEs) were analyzed. The mean heavy metal concentrations (in mg/kg, dry weight) ranged within 0.18-1.53 (Hg), 50.08-200.18 (Cu), 118.70-313.65 (Zn), 50.77-310.85 (Cr), 37.12-92.72 (Pb) and 13.29-197.24 (As), and Cu, Zn and As have been regarded as the main metal pollutants. The levels of PBDEs (1.2-12.1 ng/g) and BDE-209 (2.4-30.5 ng/g) were at the middle level of the global range. BDE-209 was the predominant congener (67.0%-85.7%), which agrees with the fact that technical deca-BDE mixtures are the dominant PBDE formulation in China. The relative high level of PTS pollutants in the western part of the city is probably owing to the intensive agricultural activities and lack of sewerage system there. The ecological risk assessment with the sediment quality guidelines (SOGs) indicates that the urban river sediments in the city have been heavily contaminated by heavy metals with probable ecotoxicological impacts on freshwater organisms and the main toxic pollutants are Hg and As. The results of current study imply that the city, and perhaps many other small cities in China as well, requires immediate pollution control measures with emphasis on not only conventional organic pollutants but also on PTS such as heavy metals and PBDEs.

  1. Component, Disperse and Morphological Composition of Ambient Air Dust Contamination in the Zones of Mining-Processing Enterprises

    Science.gov (United States)

    Zagorodnov, S. Y.; Kokoulina, A. A.; Klein, S. V.

    2017-07-01

    The article presents the results of complex studies of dust emissions of the mining and processing complex. The main technological processes and the sources operation that produce intense dust emissions are determined. It has been proved that dust emissions of the investigated enterprise contain fine dust dangerous for human health. The results of the studies allowed us to detect precisely the dispersed composition of dust emissions, with the separation of PM10 and PM2.5 fractions, the chemical composition of the dust, and the shape of the particles. Thus, operating with obtained data on dispersed composition of the dust emissions and the specified sedimentation coefficient, we were able to calculate the dispersion of all solid particles and separately the PM10 and PM2.5 at the location of the enterprise. The dust exposure of the population at the targeted zones has been also determined. The obtained concentration values were used for assess health risk level to population living at the border of sanitary protection zone of the enterprise. Due to the obtained results, the enterprise was provided with recommendations on the inclusion of fine particles PM 10 and PM 2.5 in the production control program. In the case of increasing its production capacity was recommended to introduce the environmental measures for the reduction of emission of the finely dispersed fractions PM10 and PM 2.5.

  2. Bacterial biodiversity analysis of a contaminated soil from the Chernobyl exclusion zone and characterization of the committed interaction of a Microbacterium strain with uranium

    International Nuclear Information System (INIS)

    Theodorakopoulos, Nicolas

    2013-01-01

    The nuclear power plants accidents of Chernobyl and Fukushima demonstrate the importance of the understanding of the transfer of the radioactive contamination in the environment and its ecological consequences. Although certain studies have been realized on superior organisms of the food chain, studies on telluric bacterial communities are scarce. The latter play nevertheless an essential role in the mobility of contaminants in soils by decreasing or improving their transfer towards other compartments (water, vegetables and animals). Moreover radionuclides (RNs) can have toxic effects on bacteria, leading to an inhibition of their participation in such transfer. The objectives of this study were (1) to estimate the impact of the radioactive contamination on bacterial communities belonging to a soil of the Chernobyl exclusion zone (trench T22) and (2) to study the uranium-bacteria interactions of a resistant strain, isolated from this soil. The various techniques used to characterize the bacterial diversity (culture of bacteria, DGGE, 454 pyro-sequencing) all testified of the multiplicity and the abundance of the bacterial communities in spite of the contamination. An impact on the community structure was difficult to assess by DGGE or cultural approach, but was nevertheless highlighted by the use of pyro-sequencing, suggesting the presence of species more adapted to the contaminated soil conditions. A specific molecular tool dedicated to the search of bacteria affiliated to the known radiation resistant Deinococcus-Thermus phylum (for example the Deinococcus radiodurans specie survives after an irradiation of several kGy) was developed. However it did not reveal the presence of bacteria affiliated to such a phylum in the studied soil. In parallel to the study of the bacterial biodiversity, about fifty culturable bacteria were isolated from this site and were used as a support to select a species (Microbacterium) capable to survive strong U(VI) concentrations. The

  3. OPERATIONAL LIMITATIONS FOR DEMOLITION OF A HIGHLY ALPHA CONTAMINATED BUILDING MODLES VERSUS MEASURED AIR & SURFACE ACTIVITY CONCENTRATIONS

    Energy Technology Data Exchange (ETDEWEB)

    LLOYD, E.R.

    2006-11-02

    The demolition of a facility historically used for processing and handling transuranic materials is considered. Residual alpha emitting radionuclide contamination poses an exposure hazard if released to the local environment during the demolition. The process of planning for the demolition of this highly alpha contaminated building, 232-Z, included a predemolition modeling analysis of potential exposures. Estimated emission rates were used as input to an air dispersion model to estimate frequencies of occurrence of peak air and surface exposures. Postdemolition modeling was also conducted, based on the actual demolition schedule and conditions. The modeling results indicated that downwind deposition is the main operational limitation for demolition of a highly alpha-contaminated building. During the demolition of 232-Z, airborne radiation and surface contamination were monitored. The resultant non-detect monitoring results indicate a significant level of conservatism in the modeled results. This comparison supports the use of more realistic assumption in the estimating emission rates. The resultant reduction in modeled levels of potential exposures has significant implications in terms of the projected costs of demolition of such structures.

  4. OPERATIONAL LIMITATIONS FOR DEMOLITION OF A HIGHLY ALPHA-CONTAMINATED BUILDING- MODELED VERSUS MEASURED AIR and SURFACE ACTIVITY CONCENTRATIONS

    International Nuclear Information System (INIS)

    LLOYD, E.R.

    2006-01-01

    The demolition of a facility historically used for processing and handling transuranic materials is considered. Residual alpha emitting radionuclide contamination poses an exposure hazard if released to the local environment during the demolition. The process of planning for the demolition of this highly alpha contaminated building, 232-Z, included a predemolition modeling analysis of potential exposures. Estimated emission rates were used as input to an air dispersion model to estimate frequencies of occurrence of peak air and surface exposures. Postdemolition modeling was also conducted, based on the actual demolition schedule and conditions. The modeling results indicated that downwind deposition is the main operational limitation for demolition of a highly alpha-contaminated building. During the demolition of 232-Z, airborne radiation and surface contamination were monitored. The resultant non-detect monitoring results indicate a significant level of conservatism in the modeled results. This comparison supports the use of more realistic assumption in the estimating emission rates. The resultant reduction in modeled levels of potential exposures has significant implications in terms of the projected costs of demolition of such structures

  5. Surface contamination of counting tools after mock dispensing of cyclophosphamide in a simulated outpatient pharmacy.

    Science.gov (United States)

    Chaffee, Bruce W; Lander, Michael J; Christen, Catherine; Redic, Kimberly A

    2018-01-01

    Purpose The primary aim was to determine if dispensing of cyclophosphamide tablets resulted in accumulated residue on pharmacy counting tools during a simulated outpatient dispensing process. Secondary objectives included determining if cyclophosphamide contamination exceeded a defined threshold level of 1 ng/cm 2 and if a larger number of prescriptions dispensed resulted in increased contamination. Methods Mock prescriptions of 40 cyclophosphamide 50 mg tablets were counted on clean trays in three scenarios using a simulated outpatient pharmacy after assaying five cleaned trays as controls. The three scenarios consisted of five simulated dispensings of one, three, or six prescriptions dispensed per scenario. Wipe samples of trays and spatulas were collected and assayed for all trays, including the five clean trays used as controls. Contamination was defined as an assayed cyclophosphamide level at or above 0.001 ng/cm 2 and levels above 1 ng/cm 2 were considered sufficient to cause risk of human uptake. Mean contamination for each scenario was calculated and compared using one-way analysis of variance. P-values of contamination on trays used to count one, three, and six cyclophosphamide prescriptions was 0.51 ± 0.10 (p=0.0003), 1.02 ± 0.10 (p contamination. Increasing the number of prescriptions dispensed from 1 to 3, 1 to 6, and 3 to 6 counts increased contamination by 0.51 ± 0.15 (p = 0.0140), 1.31 + 0.15 (p contaminates pharmacy counting tools, and an increased number of prescriptions dispensed correlates with increased level of contamination. Counting out three or more prescriptions leads to trays having contamination that surpasses the threshold at which worker exposure may be increased. Pharmacies should consider devoting a separate tray to cyclophosphamide tablets, as cross-contamination could occur with other drugs and the efficacy of decontamination methods is unclear. Employee exposure could be minimized with the use

  6. Radiocaesium contamination and dose rate estimation of terrestrial and freshwater wildlife in the exclusion