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Sample records for radioactive soil contamination

  1. Ecological Role of Soils upon Radioactive Contamination

    NASA Astrophysics Data System (ADS)

    Tsvetnov, Evgeny; Shcheglov, Alexei; Tsvenova, Olga

    2016-04-01

    The ecological role of soils upon radioactive contamination is clearly manifested in the system of notions about ecosystems services, i.e., benefits gained by humans from ecosystems and their components, including soils (Millennium Ecosystem Assessment, 2005). For the soils, these services are considered on the basis of soil functions in the biosphere that belong to the protective ecosystem functions within the group of soil functions known under the names of "Buffer and protective biogeocenotic shield" (at the level of particular biogeocenoses) and "Protective shield of the biosphere" (at the global biospheric level) (according to Dobrovol'skii & Nikitin, 2005). With respect to radionuclides, this group includes (1) the depositing function, i.e., the accumulation and long-term sequestration of radioactive substances by the soil after atmospheric fallout; (2) the geochemical function, i.e., the regulation of horizontal and vertical fluxes of radionuclides in the system of geochemically conjugated landscapes and in the soil-groundwater and soil-plant systems; and (3) the dose-forming function that is manifested by the shielding capacity of the soil with respect to the external ionizing radiation (lowering of the dose from external radiation) and by the regulation of the migration of radionuclides in the trophic chain (lowering of the dose from internal radiation). The depositing and geochemical functions of the soils are interrelated, which is seen from quantitative estimates of the dynamics of the fluxes of radionuclides in the considered systems (soil-plant, soil-groundwater, etc.). The downward migration of radionuclides into the lower soil layers proceeds very slowly: for decades, more than 90% of the pool of radionuclides is stored in the topmost 10 cm of the soil profile. In the first 3-5 years after the fallout, the downward migration of radionuclides with infiltrating water flows decreases from several percent to decimals and hundredths of percent from the

  2. Radioactivity measurement of radioactive contaminated soil by using a fiber-optic radiation sensor

    NASA Astrophysics Data System (ADS)

    Joo, Hanyoung; Kim, Rinah; Moon, Joo Hyun

    2016-06-01

    A fiber-optic radiation sensor (FORS) was developed to measure the gamma radiation from radioactive contaminated soil. The FORS was fabricated using an inorganic scintillator (Lu,Y)2SiO5:Ce (LYSO:Ce), a mixture of epoxy resin and hardener, aluminum foil, and a plastic optical fiber. Before its real application, the FORS was tested to determine if it performed adequately. The test result showed that the measurements by the FORS adequately followed the theoretically estimated values. Then, the FORS was applied to measure the gamma radiation from radioactive contaminated soil. For comparison, a commercial radiation detector was also applied to measure the same soil samples. The measurement data were analyzed by using a statistical parameter, the critical level to determine if net radioactivity statistically different from background was present in the soil sample. The analysis showed that the soil sample had radioactivity distinguishable from background.

  3. Characterization and remediation of highly radioactive contaminated soil at Hanford

    SciTech Connect

    Buckmaster, M.A.; Erickson, J.K.

    1993-09-01

    The Hanford Site, Richland, Washington, contains over 1,500 identified waste sites and numerous groundwater plumes that will be characterized and remediated over the next 30 years. As a result of the Hanford Federal Facility Agreement and Consent Order, the US Department of Energy (DOE) has initiated a remedial investigation/feasibility study (RI/FS) at the 200-BP-1 operable unit. The 200-BP-1 RI/FS is the first Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) investigation on the Hanford Site that involves highly radioactive and chemically contaminated soils. The initial phase of site characterization was designed to assess the nature and extent of contamination associated with the source waste sites within the 200-BP-1 operable unit. Characterization activities consisted of drilling and sampling, chemical and physical analysis of samples, and development of a conceptual vadose zone model. These data were then used. to develop remedial alternatives during the FS evaluation. The preferred alternative resulting from the RI/FS process for the 200-BP-1 operable unit is to construct a surface isolation barrier. The multi-layered earthen barrier will be designed to prevent migration of contaminants resulting from water infiltration, biointrusion, and wind and water erosion.

  4. Immobilization of radioactive strontium in contaminated soils by phosphate treatment

    SciTech Connect

    Kim, K.H.; Ammons, J.T. . Dept. of Plant and Soil Science); Lee, S.Y. )

    1990-01-01

    The feasibility of in situ phosphate- and metal- (calcium, aluminum, and iron) solution treatment for {sup 90}Sr immobilization was investigated. Batch and column experiments were performed to find optimum conditions for coprecipitation of {sup 90}Sr with Ca-, Al-, and Fe-phosphate compounds in contaminated soils. Separate columns were packed with artificially {sup 85}Sr-contaminated acid soil as well as {sup 90}Sr-contaminated soil from the Oak Ridge Reservation. After metal-phosphate treatment, the columns were then leached successively with either tapwater or 0.001 M CaCl{sub 2} solution. Most of the {sup 85}Sr coprecipitated with the metal phosphate compounds. Immobilization of {sup 85}Sr and {sup 90}Sr was affected by such factors as solution pH, metal and phosphate concentration, metal-to-phosphate ratio, and soil characteristics. Equilibration time after treatments also affected {sup 85}Sr immobilization. Many technology aspects still need to be investigated before field applications are feasible, but these experiments indicate that phosphate-based in situ immobilization should prevent groundwater contamination and will be useful as a treatment technology for {sup 90}Sr-contaminated sites. 15 refs., 3 figs., 1 tab.

  5. Local variation of soil contamination with radioactive cesium at a farm in Fukushima.

    PubMed

    Sato, Itaru; Natsuhori, Masahiro; Sasaki, Jun; Satoh, Hiroshi; Murata, Takahisa; Nakamura, Tatsuro; Otani, Kumiko; Okada, Keiji

    2016-02-01

    Radioactive cesium concentration in soil was measured at 27 sections with 5 points per section, and surface dose of ground was measured at 10 sections with 13 points per section at a farm in Fukushima to assess local variation of soil contamination with radioactive cesium. As for the cesium in soil, averages of the coefficient of variance (CV) and the maximum/minimum ratio in each section were 49% and 4.9, respectively. As for the surface dose, average of its CV in each section was 20% and the maximum/minimum ratio reached a maximum of 3.0. These findings suggest that exact evaluation of soil contamination with cesium is difficult. Small changes or differences in soil contamination may not be detected in studies of the environmental radioactivity. PMID:27348893

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

    SciTech Connect

    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.

  7. Bioavailability of caesium-137 from chernozem soils with high and low levels of radioactive contamination

    NASA Astrophysics Data System (ADS)

    Paramonova, Tatiana; Shamshurina, Eugenia; Machaeva, Ekaterina; Belyaev, Vladimir

    2014-05-01

    Bioavailability of Cs-137 in "soil-plant" system of radioactively contaminated terrestrial ecosystems is the most important factor in the understanding of ecological situation. There are many factors affecting the features of Cs-137 biogeochemical cycle: period since an accident, type and intensity of radioactive fallout, general properties of landscape and the specifics of soil and plant covers, etc. In order to evaluate the importance of soil contamination level for the process of Cs-137 translocation from soil to plant the research in forest-steppe areas of Russia with similar natural properties, but contrasting high (Tula region) and low (Kursk region) levels of radioactive Chernobyl fallout (about 25 years after accident) was conducted. Soil cover of both sites is presented by chernozems with bulk density 1.1-1.2 g/cm3, 6-7% humus and neutral pH 6.5-7.2; plant cover under investigation consist of dry and wet meadows with bioproductivity 1.6-2.5 kg/m2 and 85-90% of biomass concentrated underground, that is typical for Russian forest-steppe landscapes. At the same time levels of soil regional contamination with Cs-137 differ by an order - 620-710 Bq/kg (210-250 kBq/m2) in Tula region and 30-55 Bq/kg (10-20 kBq/m2) in Kursk region. At a higher level of soil radioactive contamination specific activity of Cs-137 in vegetation of meadows is noticeably increased (103-160 Bq/kg in Tula region versus 12-14 Bq/kg in Kursk region) with correlation coefficient r 0.87. Increasing of Cs-137 in the underground parts of plants plays a decisive role in this process, while the specific radionuclide's activity in the aboveground parts of different sites is almost invariant (and ubiquitously roots contain 2-5 times more Cs-137 than shoots). The values of transfer factors for Cs-137 (the ratio of the specific Cs-137 activities in the plant tissue and in the soil) at various levels of soil radioactive contamination vary within a relatively narrow range 0.1-0.4, that confirms the

  8. On-site radioactive soil contamination at the Andreeva Bay shore technical base, Northwest Russia.

    PubMed

    Reistad, O; Dowdall, M; Selnaes, Ø G; Standring, W J F; Hustveit, S; Steenhuisen, F; Sørlie, A

    2008-07-01

    The radioactive waste (RAW) storage site at Andreeva Bay in the Russian Northwest has experienced radioactive contamination both as a result of activities carried out at the site and due to incidents that have occurred there in the past such as accidental releases of radioactive materials. The site is an interesting case study for decommissioning due to the extremely large amounts of radioactivity present at the site and the conditions under which it is stored; very little has been previously published in the scientific literature about this site. This paper complements the paper describing dose rates at Andreeva Bay which is published in this issue of Journal of Environmental Radioactivity by the same authors. This study presents new data related to the activity concentrations of (137)Cs and (90)Sr in surface soils and measurements of alpha- and beta-particle fluxes taken at different areas around the site. Limited data on 60Co is also presented. The results of the study indicate that the main areas of site contamination are associated with the former spent nuclear fuel storage facility at Building 5, due to accidental discharges which began in 1982. Substantial contamination is also observed at the solid radioactive waste storage facilities, probably due to the ingress of water into these facilities. More than 240 samples were measured: maximum contamination levels were 1 x 10(6)Bq/kg (137)Cs (mean value 4.1 x 10(5)Bq/kg) and 4 x 10(6)Bq/kg (90)Sr (mean value 1.2 x1 0(5)Bq/kg). Localised patches of alpha and beta contamination were also observed throughout the site. PMID:18276046

  9. Soil treatment to remove uranium and related mixed radioactive contaminants. Final report September 1992--October 1995

    SciTech Connect

    1996-07-01

    A research and development project to remove uranium and related radioactive contaminants from soil by an ultrasonically-aided chemical leaching process began in 1993. The project objective was to develop and design, on the basis of bench-scale and pilot-scale experimental studies, a cost-effective soil decontamination process to produce a treated soil containing less than 35 pCi/g. The project, to cover a period of about thirty months, was designed to include bench-scale and pilot-scale studies to remove primarily uranium from the Incinerator Area soil, at Fernald, Ohio, as well as strontium-90, cobalt-60 and cesium-137 from a Chalk River soil, at the Chalk River Laboratories, Ontario. The project goal was to develop, design and cost estimate, on the basis of bench-scale and pilot-scale ex-situ soil treatment studies, a process to remove radionuclides form the soils to a residual level of 35 pCi/g of soil or less, and to provide a dischargeable water effluent as a result of soil leaching and a concentrate that can be recovered for reuse or solidified as a waste for disposal. In addition, a supplementary goal was to test the effectiveness of in-situ soil treatment through a field study using the Chalk River soil.

  10. Speciation of radioactive soil particles in the Fukushima contaminated area by IP autoradiography and microanalyses.

    PubMed

    Mukai, Hiroki; Hatta, Tamao; Kitazawa, Hideaki; Yamada, Hirohisa; Yaita, Tsuyoshi; Kogure, Toshihiro

    2014-11-18

    Radioactive soil particles several tens of micrometers in size were collected from litter soil in the radiation contaminated area by the Fukushima nuclear plant accident and characterized using electron and X-ray microanalyses. The radioactive particles were discriminated by autoradiography using imaging plates (IP) on which microgrids were formed by laser ablation in order to find the particles under microscopy. Fifty radioactive particles were identified and classified into three types from their morphology and chemical composition, namely: (1) aggregates of clay minerals, (2) organic matter containing clay mineral particulates, and (3) weathered biotite originating from local granite. With respect to the second type, dissolution of the organic matter did not reduce the radiation, suggesting that the radionuclides were also fixed by the clay minerals. The weathered biotite grains have a plate-like shape with well-developed cleavages inside the grains, and kaolin group minerals and goethite filling the cleavage spaces. The reduction of the radiation intensity was measured before and after the trimming of the plate edges using a focused ion beam (FIB), to examine whether radioactive cesium primarily sorbed at frayed edges. The radiation was attenuated in proportion to the volume decrease by the edge trimming, implying that radioactive cesium was sorbed uniformly in the porous weathered biotite. PMID:25343443

  11. Application of in-situ gamma spectrometry in the remediation of radioactively contaminated soil

    SciTech Connect

    Sutton, C.; Yesso, J.D.; Danahy, R.J.; Cox, T.

    1999-06-01

    The Fernald Environmental Management Project (FEMP) is a US Department of Energy site that is undergoing total remediation and closure. Most of the remediation effort entails massive excavation of soil for disposal, both offsite and onsite, at an engineered disposal facility. In-situ gamma spectrometry is routinely used to support soil excavation operations to accurately and quickly identify soil areas as being above or below regulatory remediation criteria. Two different in-situ gamma spectrometry systems are used. The first is a sodium iodide (NaI) detector mounted either on a tractor or a jogging stroller, depending on the terrain to be measured. The NaI system allows the collection of a gamma energy spectrum which can be analyzed to identify and quantify radioactive isotopes which are present within the detector`s viewing area. Each energy spectrum is tagged by location coordinates provided by an on-board global positioning system (GPS) to precisely locate elevated contamination areas. The second is a tripod-mounted, high purity germanium detector (HPGe) gamma spectrometry system that is functionally similar to the NaI system. The principal advantage of the HPGe is its superior resolution, which allows much more accurate identification and quantification of radionuclide contaminants in soils. In order to effectively utilize the data quality objective process with these systems, three quality assurance (QA) elements had to be performed.

  12. Vadose zone characterization of highly radioactive contaminated soil at the Hanford Site

    SciTech Connect

    Buckmaster, M.A.

    1993-05-01

    The Hanford Site in south-central Washington State contains over 1500 identified waste sites and numerous groundwater plumes that will be characterized and remediated over the next 30 years. As a result of the Hanford Federal Facility Agreement and Consent Order, the US Department of Energy has initiated a remedial investigation/feasibility study at the 200-BP-1 operable unit. The 200-BP-1 remedial investigation is the first Comprehensive Environmental Response, Compensation, and Liability Act of 1980 investigation on the Hanford Site that involves drilling into highly radioactive and chemically contaminated soils. The initial phase of site characterization was designed to assess the nature and extent of contamination associated with the source waste site within the 200-BP-1 operable unit. Characterization activities consisted of drilling and sampling the waste site, chemical and physical analysis of samples, and development of a conceptual vadose zone model. Predicted modeling concentrations compared favorably to analytical data collected during the initial characterization activities.

  13. Lateral migration of Caesium-137 as a heterogeneity factor of soil radioactive contamination within small catchments

    NASA Astrophysics Data System (ADS)

    Shamshurina, Evgeniya

    2014-05-01

    Caesium-137 is long-lived artificial radionuclide with half-life of about 30.17 years. Due to Chernobyl accident in 1986 were received 270-280 PBq of 137Cs. The radioactive material is spread in different directions and then fell to the vast territory on the earth's surface as part of rainfall and under the influence of gravity. The deposition of 137Cs was very heterogeneous due to significant impact of changing weather conditions during the accident. Fixing 137Cs in the soil is because of the high content in the upper layer of fine fractions (especially clay) and organic substances that increase the sorption properties of soil. As a result of small vertical migration down the soil profile, the main migration processes of 137Cs is lateral migration which may occur in soil particles under the deflation but mainly water erosion.The aim of this study was to analyze the main factors of changing the current radioecological situation of small catchments in Chernozem zone of European Russia. The 1st small catchment with total area 1.98 km2 is located in the Kursk Region, where 137Cs soil inventories currently does not exceed 37 kBq/m2. The 2nd small catchment with total area 0.99 km2 is located in the Tula Region called "Plavsk Cs deposition hotspot" was highly contaminated with radioactive fallout with levels up to 600 kBq/m2.For reconstruction of 137Cs initial fallout was defined 4 references sites in Kursk Region and 5 sites in Tula Region. All reference sites were located at the flat interfluve areas in or nearby the study catchment. The analysis of 137Cs inventory within 1st study site references did not show significant differences between them which indicates the absence of the initial fallout heterogeneity. The mean values of 137Cs inventory is 8,7±0,5 kBq/m2 and Cv varies in a range of 13-22%, which are typical for the faraway from Chernobyl territory. Based on 4 references was created the map of initial Chernobyl fallout using the formula of radioactive decay

  14. Demolition and removal of radioactively contaminated concrete soil: Aerosol control and monitoring

    SciTech Connect

    Newton, G.J.; Hoover, M.D.; Grace, A.C. III

    1995-12-01

    From 1963 to 1985, two concrete-lined ponds were used to reduce the volume of radioactive liquids from the Institute`s research programs. Following withdrawal of the {open_quotes}hot ponds{close_quotes} from active use, the residual sludges and plastic liners of the ponds were removed and shipped to a radioactive waste disposal site. From 1987 to 1994, the concrete structures remained undisturbed pending environmental restoration on the site. Restoration began in 1994 and was completed in 1995. Restoration involved mechanical breakup and removal of the concrete structures and removal of areas of contaminated soils from the site. This report describes the design and results of the aerosol control and monitoring program that was conducted to ensure protection of workers and the environment during the restoration process. The aerosol control and monitoring strategy developed for remediation of the ITRI hot ponds was successful both in preventing dispersion of radioactive dusts and in demonstrating that exposures of workers and offsite releases were within statutory limits.

  15. (Contaminated soil)

    SciTech Connect

    Siegrist, R.L.

    1991-01-08

    The traveler attended the Third International Conference on Contaminated Soil, held in Karlsruhe, Germany. The Conference was a status conference for worldwide research and practice in contaminated soil assessment and environmental restoration, with more than 1500 attendees representing over 26 countries. The traveler made an oral presentation and presented a poster. At the Federal Institute for Water, Soil and Air Hygiene, the traveler met with Dr. Z. Filip, Director and Professor, and Dr. R. Smed-Hildmann, Research Scientist. Detailed discussions were held regarding the results and conclusions of a collaborative experiment concerning humic substance formation in waste-amended soils.

  16. Comparing radiation dose rates in soils and riverine sediment to track the dispersion of radioactive contamination in Fukushima coastal rivers

    NASA Astrophysics Data System (ADS)

    Evrard, Olivier; Onda, Yuichi; Lepage, Hugo; Chartin, Caroline; Lefèvre, Irène; Cerdan, Olivier; Bonté, Philippe; Ayrault, Sophie

    2014-05-01

    The Fukushima Dai-ichi nuclear power plant (FDNPP) accident that occurred in March 2011 led to the formation of a 3000-km² radioactive pollution plume on soils located up to 70 km to the northwest of the damaged site. Forests and paddy fields are the dominant land uses in this mountainous region drained to the Pacific Ocean by several rivers that flow across densely inhabited coastal plains. It is then crucial to track the dispersion of radioactive material conveyed by those rivers to estimate the continental supply of radionuclides to the Ocean and to assess redistribution of radioactive sediment in those catchments. Radiations emitted by this contaminated material may indeed lead to an external exposure threat for local populations. As river discharge and sediment concentration data were not available during the first two years that followed the accident, alternative methods had to be developed to track this dispersion. We therefore organized field campaigns every six months and conducted local ground dose rate measurements to estimate whether fresh sediment drape deposits were more or less contaminated compared to local soils. Overall, our results showed that, in those regions exposed to violent typhoons and spring snowmelt, transfers of sediment are massive and episodic, and that they followed a seasonal cycle in 2011-2012. Then, in May 2013, contamination levels measured in sediment found in the upper parts of the catchments were almost systematically lower than the ones measured in nearby soils, whereas their contamination was higher in the coastal plains. This could have indicated a drying-up of the upstream sources of contamination. However, after the violent typhoons that occurred during summer in 2013, dose rates measured in fresh sediment deposits in November 2013 increased again systematically across the region. We thereby suggest that remobilization of contaminated sediment by typhoons and their storage in reservoirs and in coastal sections of the

  17. EMERGING TECHNOLOGY SUMMARY: VITRIFICATION OF SOILS CONTAMINATED BY HAZARDOUS AND/OR RADIOACTIVE WASTES

    EPA Science Inventory

    A performance summary of an advanced multifuel-capable combustion and melting system (CMS) for the vitrification of hazardous wastes is presented. Vortex Corporation has evaluated its patented CMS for use in the remediation of soils contaminated with heavy metals and radionuclid...

  18. Airborne radioactive contamination monitoring

    SciTech Connect

    Whitley, C.R.; Adams, J.R.; Bounds, J.A.; MacArthur, D.W.

    1996-03-01

    Current technologies for the detection of airborne radioactive contamination do not provide real-time capability. Most of these techniques are based on the capture of particulate matter in air onto filters which are then processed in the laboratory; thus, the turnaround time for detection of contamination can be many days. To address this shortcoming, an effort is underway to adapt LRAD (Long-Range-Alpha-Detection) technology for real-time monitoring of airborne releases of alpa-emitting radionuclides. Alpha decays in air create ionization that can be subsequently collected on electrodes, producing a current that is proportional to the amount of radioactive material present. Using external fans on a pipe containing LRAD detectors, controlled samples of ambient air can be continuously tested for the presence of radioactive contamination. Current prototypes include a two-chamber model. Sampled air is drawn through a particulate filter and then through the first chamber, which uses an electrostatic filter at its entrance to remove ambient ionization. At its exit, ionization that occurred due to the presence of radon is collected and recorded. The air then passes through a length of pipe to allow some decay of short-lived radon species. A second chamber identical to the first monitors the remaining activity. Further development is necessary on air samples without the use of particulate filtering, both to distinguish ionization that can pass through the initial electrostatic filter on otherwise inert particulate matter from that produced through the decay of radioactive material and to separate both of these from the radon contribution. The end product could provide a sensitive, cost-effective, real-time method of determining the presence of airborne radioactive contamination.

  19. Effects of low-level radioactive soil contamination and sterilization on the degradation of radiolabeled wheat straw.

    PubMed

    Niedrée, Bastian; Vereecken, Harry; Burauel, Peter

    2012-07-01

    After the explosion of reactor 4 in the nuclear power plant near Chernobyl, huge agricultural areas became contaminated with radionuclides. In this study, we want to elucidate whether (137)Cs and (90)Sr affect microorganisms and their community structure and functions in agricultural soil. For this purpose, the mineralization of radiolabeled wheat straw was examined in lab-scale microcosms. Native soils and autoclaved and reinoculated soils were incubated for 70 days at 20 °C. After incubation, the microbial community structure was compared via 16S and 18S rDNA denaturing gradient gel electrophoresis (DGGE). The radioactive contamination with (137)Cs and (90)Sr was found to have little effect on community structure and no effect on the straw mineralization. The autoclaving and reinoculation of soil had a strong influence on the mineralization and the community structure. Additionally we analyzed the effect of soil treatment on mineralization and community composition. It can be concluded that other environmental factors (such as changing content of dissolved organic carbon) are much stronger regulating factors in the mineralization of wheat straw and that low-level radiation only plays a minor role. PMID:22248931

  20. Significant radioactive contamination of soil around a coal-fired thermal power plant.

    PubMed

    Papp, Z; Dezso, Z; Daróczy, S

    2002-01-01

    Soil samples were collected around a coal-fired power plant from 81 different locations. Brown coal, unusually rich in uranium, is burnt in this plant that lies inside the confines of a small industrial town and has been operational since 1943. Activity concentrations of the radionuclides 238U, 226Ra, 232Th, 137Cs and 40K were determined in the samples. Considerably elevated concentrations of 238U and 226Ra have been found in most samples collected within the inhabited area. Concentrations of 235U and 226Ra in soil decreased regularly with increasing depth at many locations, which can be explained by fly-ash fallout. Concentrations of 235U and 226Ra in the top (0-5 cm depth) layer of soil in public areas inside the town are 4.7 times higher, on average, than those in the uncontaminated deeper layers, which means there is about 108 Bq kg(-1) surplus activity concentration above the geological background. A high emanation rate of 222Rn from the contaminated soil layers and significant disequilibrium between 238U and 226Ra activities in some kinds of samples have been found. PMID:11900206

  1. In situ vitrification: Immobilizing radioactive contaminants in place by melting soils into man-made rocks

    SciTech Connect

    Jacobs, G.K.; Spalding, B.P. ); Tixier, J.S. )

    1992-01-01

    From 1951 to 1966 over 1 [times] 10[sup 6] Ci of Cs-137, Sr-90, and other radioisotopes in liquid wastes were disposed of in shallow seepage pits at ORNL. In situ methods to stabilize these sites are being investigated because of radiation exposure risks to personnel during excavation and removal activities. A field test at ORNL of In Situ Vitrification (ISV) was performed to evaluate its ability to resistance heating through graphite electrodes to melt contaminated soils in place. The resulting small lava lake cools and solidifies to a rock consisting of glassy and crystalline material. Volatile products released from the surface of the melt are collected and treated. The Sr-90 was incorporated into mineral phases and residual glass that form upon solidification. The Cs-137, however, is incompatible with the mineral structures and is concentrated into the small amount of residual glass that is trapped in the interstices between mineral grains. Leach tests were performed on samples of sludge, sludge + soil, crushed ISV rock, crushed ISV rock + soil, and low surface area fragments of ISV rock. First, sequential extractions with 0.1 N CaCl[sub 2] were used. Then, sequential treatments with 0.1 N HCl were used. Approximately 10% of the Sr-90 was released from the sludge, with or without soil, after CaCl[sub 2] was applied. Subsequent treatment with HCl released essentially all the Sr-90. The Sr-90 in the crushed ISV rock was resistant to cation exchange, with only 0.4% leached after treatment with CaCl[sub 2]. Treatment with HCl released only 4% of the total Sr-90 present in the crushed ISV rock. The low surface area fragments, more representative of expected field conditions, released 10 [times] less of the Sr-90 than the crushed ISV rock samples. The Cs-137 was not significantly leached from any of the samples of sludge or ISV rock.

  2. Mineralogical and geomicrobial examination of soil contamination by radioactive Cs due to 2011 Fukushima Daiichi Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Akai, Junji; Nomura, Nao; Matsushita, Shin; Kudo, Hisaaki; Fukuhara, Haruo; Matsuoka, Shiro; Matsumoto, Jinko

    Soil contamination by radioactive Cs from Fukushima Daiichi Nuclear Power Plant accident was investigated. Absorption and desorption experiments of Cs were conducted for several phyllosillicates (kaolinite, sericite, montmorillonite, vermiculite, chrysotile and biotite), zeolite and solid organic matter (dead and green leaves). The results confirmed the characteristic sorption and desorption of Cs by these materials. The 2:1 type phyllosilicate, especially, vermiculite and montmorillonite absorbed Cs well. Heated vermiculite for agricultural use and weathered montmorillonite also adsorbed Cs. Leaves also absorbed Cs considerably but easily desorbed it. In summary, the relative capacity and strength of different materials for sorption of Cs followed the order: zeolite (clinoptilolite) > 2:1 type clay mineral > 1:1 type clay mineral > dead and green leaves. Culture experiments using bacteria of both naturally living on dead leaves in Iitate village, Fukushima Pref. and bacterial strains of Bacillus subtillis, Rhodococus erythropolis, Streptomyces aomiensis and Actinomycetospora chlora were carried out. Non-radioactive 1% Cs solution (CsCl) was added to the culture media. Two types of strong or considerable bacterial uptakes of Cs were found in bacterial cells. One is that Cs was contained mainly as globules inside bacteria and the other is that Cs was absorbed in the whole bacterial cells. The globules consisted mainly of Cs and P. Based on all these results, future diffusion and re-circulation behavior of Cs in the surface environment was discussed.

  3. The assumption of heterogeneous or homogeneous radioactive contamination in soil/sediment: does it matter in terms of the external exposure of fauna?

    PubMed

    Beaugelin-Seiller, K

    2014-12-01

    The classical approach to environmental radioprotection is based on the assumption of homogeneously contaminated media. However, in soils and sediments there may be a significant variation of radioactivity with depth. The effect of this heterogeneity was investigated by examining the external exposure of various sediment and soil organisms, and determining the resulting dose rates, assuming a realistic combination of locations and radionuclides. The results were dependent on the exposure situation, i.e., the organism, its location, and the quality and quantity of radionuclides. The dose rates ranged over three orders of magnitude. The assumption of homogeneous contamination was not consistently conservative (if associated with a level of radioactivity averaged over the full thickness of soil or sediment that was sampled). Dose assessment for screening purposes requires consideration of the highest activity concentration measured in a soil/sediment that is considered to be homogeneously contaminated. A more refined assessment (e.g., higher tier of a graded approach) should take into consideration a more realistic contamination profile, and apply different dosimetric approaches. PMID:25170547

  4. Apparatus development for measurement of (134)Cs and (137)Cs radioactivity of soil contaminated by the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Kajimoto, Tsuyoshi; Endo, Satoru; Tanaka, Kenichi; Okashiro, Yasuharu; Kai, Hiroaki; Fujii, Syuuji; Mishima, Atsushi; Matsubara, Takahide; Yoshida, Shinji

    2016-09-01

    We developed an apparatus containing a NaI(Tl) scintillator to measure the (134)Cs and (137)Cs radioactivity of soil contaminated by the Fukushima Daiichi Nuclear Power Plant accident. The unfolding method with the least-squares technique was used to determine the radioactivity. Detector responses for each radionuclide in soil were calculated with EGS5 code for the unfolding method. The radionuclides that were measured were (40)K, (134)Cs, (137)Cs, (208)Tl, (214)Bi, and (228)Ac. The measured spectrum agreed well with the spectrum calculated from the response matrix and measured radioactivities. The unfolding method allows us to use the NaI(Tl) scintillator despite the overlap of peaks. PMID:27289189

  5. Evaluating soil contamination

    SciTech Connect

    Beyer, W.

    1990-07-01

    The compilation was designed to help U.S. Fish and Wildlife Service contaminant specialists evaluate the degree of contamination of a soil, based on chemical analyses. Included are regulatory criteria, opinions, brief descriptions of scientific articles, and miscellaneous information that might be useful in making risk assessments. The intent was to make hard-to-obtain material readily available to contaminant specialists, but not to critique the material or develop new criteria. The compilation is to be used with its index, which includes about 200 contaminants. Entries include soil contaminant criteria from other countries, contaminant guidelines for applying sewage sludge to soil, guidelines for evaluating sediments, background soil concentrations for various elements, citations to scientific articles that may help estimate the potential movement of soil contaminants into wildlife food chains, and a few odds and ends. Articles on earthworms were emphasized because they are a natural bridge between soil and many species of wildlife.

  6. Environmental Geochemistry of Radioactive Contamination

    NASA Astrophysics Data System (ADS)

    Siegel, M. D.; Bryan, C. R.

    2003-12-01

    Psychometric studies of public perception of risk have shown that dangers associated with radioactive contamination are considered the most dreaded and among the least understood hazards (Slovic, 1987). Fear of the risks associated with nuclear power and associated contamination has had important effects on policy and commercial decisions in the last few decades. In the US, no new nuclear power plants were ordered between 1978 and 2002, even though it has been suggested that the use of nuclear power has led to significantly reduced CO2 emissions and may provide some relief from the potential climatic changes associated with fossil fuel use. The costs of the remediation of sites contaminated by radioactive materials and the projected costs of waste disposal of radioactive waste in the US dwarf many other environmental programs. The cost of disposal of spent nuclear fuel at the proposed repository at Yucca Mountain will likely exceed 10 billion. The estimated total life cycle cost for remediation of US Department of Energy (DOE) weapons production sites ranged from 203-247 billion dollars in constant 1999 dollars, making the cleanup the largest environmental project on the planet (US DOE, 2001). Estimates for the cleanup of the Hanford site alone exceeded $85 billion through 2046 in some of the remediation plans.Policy decisions concerning radioactive contamination should be based on an understanding of the potential migration of radionuclides through the geosphere. In many cases, this potential may have been overestimated, leading to decisions to clean up contaminated sites unnecessarily and exposing workers to unnecessary risk. It is important for both the general public and the scientific community to be familiar with information that is well established, to identify the areas of uncertainty and to understand the significance of that uncertainty to the assessment of risk.

  7. 49 CFR 175.705 - Radioactive contamination.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Radioactive contamination. 175.705 Section 175.705... Regulations Applicable According to Classification of Material § 175.705 Radioactive contamination. (a) A... (radioactive) materials that may have been released from their packagings. (b) When contamination is present...

  8. 49 CFR 175.705 - Radioactive contamination.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Radioactive contamination. 175.705 Section 175.705... Regulations Applicable According to Classification of Material § 175.705 Radioactive contamination. (a) A... (radioactive) materials that may have been released from their packagings. (b) When contamination is present...

  9. 49 CFR 175.705 - Radioactive contamination.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Radioactive contamination. 175.705 Section 175.705... Regulations Applicable According to Classification of Material § 175.705 Radioactive contamination. (a) A... (radioactive) materials that may have been released from their packagings. (b) When contamination is present...

  10. 49 CFR 175.705 - Radioactive contamination.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Radioactive contamination. 175.705 Section 175.705... Regulations Applicable According to Classification of Material § 175.705 Radioactive contamination. (a) A... (radioactive) materials that may have been released from their packagings. (b) When contamination is present...

  11. 49 CFR 175.705 - Radioactive contamination.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Radioactive contamination. 175.705 Section 175.705... Regulations Applicable According to Classification of Material § 175.705 Radioactive contamination. (a) A... (radioactive) materials that may have been released from their packagings. (b) When contamination is present...

  12. Remediating munitions contaminated soils

    SciTech Connect

    Shea, P.J.; Comfort, S.D.

    1995-10-01

    The former Nebraska Ordnance Plant (NOP) at Mead, NE was a military loading, assembling, and packing facility that produced bombs, boosters and shells during World War II and the Korean War (1942-1945, 1950-1956). Ordnances were loaded with 2,4,6-trinitrotoluene (TNT), amatol (TNT and NH{sub 4}NO{sub 3}), tritonal (TNT and Al) and Composition B (hexahydro-1,3,5-trinitro-1,3,5-triazine [RDX] and TNT). Process waste waters were discharged into wash pits and drainage ditches. Soils within and surrounding these areas are contaminated with TNT, RDX and related compounds. A continuous core to 300 cm depth obtained from an NOP drainage ditch revealed high concentrations of TNT in the soil profile and substantial amounts of monoamino reduction products, 4-amino-2,6-dinitrotoluene (4ADNT) and 2-amino-4,6-dinitrotoluene (2ADNT). Surface soil contained TNT in excess of 5000 mg kg{sup -1} and is believed to contain solid phase TNT. This is supported by measuring soil solution concentrations at various soil to solution ratios (1:2 to 1:9) and obtaining similar TNT concentrations (43 and 80 mg L{sup -1}). Remediating munitions-contaminated soil at the NOP and elsewhere is of vital interest since many of the contaminants are carcinogenic, mutagenic or otherwise toxic to humans and the environment. Incineration, the most demonstrated remediation technology for munitions-containing soils, is costly and often unacceptable to the public. Chemical and biological remediation offer potentially cost-effective and more environmentally acceptable alternatives. Our research objectives are to: (a) characterize the processes affecting the transport and fate of munitions in highly contaminated soil; (b) identify effective chemical and biological treatments to degrade and detoxify residues; and (c) integrate these approaches for effective and practical remediation of soil contaminated with TNT, RDX, and other munitions residues.

  13. Remediation of contaminated soils

    SciTech Connect

    Radhakrishnan, R.; Ariza, C.H.

    1997-07-01

    At least three types of zones of contamination exist whenever there is a chemical release. The impact of Non-Aqueous-Phase Liquids (NAPL) on soils and groundwater, together with the ultimate transport and migration of constituent chemicals in their dissolved or sorbed states, had led environmentalists to develop several techniques for cleaning a contaminated soil. Zone 1 represents the unsaturated zone which could be contaminated to retention capacity by both Dense Non-Aqueous-Phase Liquids (DNAPL) and Light Non-Aqueous-Phase Liquids (LNAPL). Zone 2 represents residual DNAPL or LNAPL contamination found below the groundwater table in the saturated zone. Zone 3 is represented by either the presence of NAPL dissolved in the aqueous phase, volatilized in the unsaturated zone or sorbed to either saturated or unsaturated soils. Cleanup of petroleum contaminated soils is presented in this paper. Among several techniques developed for this purpose, in-situ biological remediation is discussed in detail as a technique that does not involve excavation, thus, the costs and disruption of excavating soil are eliminated.

  14. New regulations for radiation protection for work involving radioactive fallout emitted by the TEPCO Fukushima Daiichi APP accident--disposal of contaminated soil and wastes.

    PubMed

    Yasui, Shojiro

    2014-01-01

    The accident at the Fukushima Daiichi Atomic Power Plant that accompanied the Great East Japan Earthquake on March 11, 2011, released a large amount of radioactive material. To rehabilitate the contaminated areas, the government of Japan decided to carry out decontamination work and manage the waste resulting from decontamination. In the summer of 2013, the Ministry of the Environment planned to begin a full-scale process for waste disposal of contaminated soil and wastes removed as part of the decontamination work. The existing regulations were not developed to address such a large amount of contaminated wastes. The Ministry of Health, Labour and Welfare (MHLW), therefore, had to amend the existing regulations for waste disposal workers. The amendment of the general regulation targeted the areas where the existing exposure situation overlaps the planned exposure situation. The MHLW established the demarcation lines between the two regulations to be applied in each situation. The amendment was also intended to establish provisions for the operation of waste disposal facilities that handle large amounts of contaminated materials. Deliberation concerning the regulation was conducted when the facilities were under design; hence, necessary adjustments should be made as needed during the operation of the facilities. PMID:24856781

  15. Status of outdoor radioactive contamination at the Hanford Site

    SciTech Connect

    McKinney, S.M.; Markes, B.M.

    1994-12-01

    This document summarizes the status of outdoor radioactive contamination near Hanford Site facilities and disposal sites. It defines the nature and areal extend of the radioactively contaminated areas and describes the historical, ongoing, and planned radiological monitoring and control activities. Radioactive waste has been disposed of to the soil column since shortly after the reactors and production facilities began operating. Radioactive liquid wastes were placed directly into the ground via liquid discharges to cribs, ponds, ditches, and reverse wells. Solid wastes were placed in trenches, burial vaults, and caissons. Although the Hanford Site covers 1,450 km{sup 2}, the radioactively contaminated area is only about 36 km{sup 2} or 2.5% of the original site. Over time, contamination has migrated from some of the waste management sites through various vectors (e.g., burrowing animals, deep-rooted vegetation, erosion, containment system failure) or has been deposited to the surface soil via spills and unplanned releases (e.g., line leaks/breaks, tank leaks, and stack discharges) and created areas of outdoor radioactivity both on and below the surface. Currently 26 km{sup 2} are posted as surface contamination and 10 km{sup 2} are posted as underground contamination.

  16. Contaminated soil stabilization demonstration

    SciTech Connect

    Kemp, C.J.; Sackschewsky, M.R.; Sampson, A.E.; Phillips, S.J.

    1991-10-01

    Long-term herbicide control along with a shotcrete cover was constructed at the Hanford Site in May 1991. The cover system allows for maintenance-free containment of contaminants by preventing wind and water transport of contaminants from the soil surface, preventing plant uptake of contaminants, and minimizing water infiltration through the soil column. The cover is composed of two parts: a commercial nonwoven geotextile material impregnated with trifluralin, and a >5-centimeter top cover of shotcrete containing polyethylene fibers. The herbicide-impregnated geotextile functions to prevent plant root growth into contaminated soil if any holes or cracks develop in the shotcrete layer. The herbicide component, trifluralin, is mixed into polymer nodules that degrade slowly over many years, thus releasing trifluralin slowly over time. The shotcrete topcover was sprayed using a sludge pump and air compressor to form a hard, impenetrable surface that prevents wind erosion and reduces water infiltration through the contaminated materials underneath. The benefits of the cover system are expected to last 20 to 30 years. 2 refs., 4 figs.

  17. Uranium-contaminated soil pilot treatment study

    SciTech Connect

    Turney, W.R.J.R.; Mason, C.F.V.; Michelotti, R.A.

    1996-12-31

    A pilot treatment study is proving to be effective for the remediation of uranium-contaminated soil from a site at the Los Alamos National Laboratory by use of a two-step, zero-discharge, 100% recycle system. Candidate uranium-contaminated soils were characterized for uranium content, uranium speciation, organic content, size fractionization, and pH. Geochemical computer codes were used to forecast possible uranium leach scenarios. Uranium contamination was not homogenous throughout the soil. In the first step, following excavation, the soil was sorted by use of the ThemoNuclean Services segmented gate system. Following the sorting, uranium-contaminated soil was remediated in a containerized vat leach process by use of sodium-bicarbonate leach solution. Leach solution containing uranium-carbonate complexes is to be treated by use of ion-exchange media and then recycled. Following the treatment process the ion exchange media will be disposed of in an approved low-level radioactive landfill. It is anticipated that treated soils will meet Department of Energy site closure guidelines, and will be given {open_quotes}no further action{close_quotes} status. Treated soils are to be returned to the excavation site. A volume reduction of contaminated soils will successfully be achieved by the treatment process. Cost of the treatment (per cubic meter) is comparable or less than other current popular methods of uranium-contamination remediation.

  18. Solvent-free synthesis and application of nano-Fe/Ca/CaO/[PO4] composite for dual separation and immobilization of stable and radioactive cesium in contaminated soils.

    PubMed

    Mallampati, Srinivasa Reddy; Mitoma, Yoshiharu; Okuda, Tetsuji; Simion, Cristian; Lee, Byeong Kyu

    2015-10-30

    This study assessed the synthesis and application of nano-Fe/Ca/CaO-based composite material for use as a separation and immobilizing treatment of dry soil contaminated by stable ((133)Cs) and radioactive cesium species ((134)Cs and (137)Cs). After grinding with nano-Fe/CaO, nano-Fe/Ca/CaO, and nano-Fe/Ca/CaO/[PO4], approximately 31, 25, and 22 wt% of magnetic fraction soil was separated. Their resultant (133)Cs immobilization values were about 78, 81, and 100%, respectively. When real radioactive cesium contaminated soil obtained from Fukushima was treated with nano-Fe/Ca/CaO/[PO4], approximately 27.3 wt% of magnetic and 72.75% of non-magnetic soil fractions were separated. The highest amount of entrapped (134)Cs and (137)Cs was found in the lowest weight of the magnetically separated soil fraction (i.e., 80% in 27.3% of treated soil). Results show that (134)Cs and (137)Cs either in the magnetic or non-magnetic soil fractions was 100% immobilized. The morphology and mineral phases of the nano-Fe/Ca/CaO/[PO4] treated soil were characterized using SEM-EDS, EPMA, and XRD analysis. The EPMA and XRD patterns indicate that the main fraction of enclosed/bound materials on treated soil included Ca/PO4 associated crystalline complexes. These results suggest that simple grinding treatment with nano-Fe/Ca/CaO/[PO4] under dry conditions might be an extremely efficient separation and immobilization method for radioactive cesium contaminated soil. PMID:25942697

  19. Computer Model Buildings Contaminated with Radioactive Material

    Energy Science and Technology Software Center (ESTSC)

    1998-05-19

    The RESRAD-BUILD computer code is a pathway analysis model designed to evaluate the potential radiological dose incurred by an individual who works or lives in a building contaminated with radioactive material.

  20. Natural radioactivity contamination problems. Report no. 2. (final)

    SciTech Connect

    Not Available

    1981-09-01

    Levels of naturally occurring radionuclides associated with the bauxite, columbium-tantalum, phosphate, tin, pumice, and titanium mineral extraction industries are reported. Data is also presented on radioactivity measurements in ground water, in selected geothermal waters, and in oil production brines. Radiation protection guidance is provided for uranium recovery from wet-process phosphate plants, for soil contamination limits, and for radiological exposure in natural caves. Dose pathways from incidental uses of naturally occurring radioactive materials are presented. Model state regulations for protecting public health and safety from use and disposal of naturally occurring radioactive material are outlined.

  1. Perspectives of Radioactive Contamination in Nuclear War

    PubMed Central

    Waters, W. R.

    1967-01-01

    The degrees of risk associated with the medical, industrial and military employment of nuclear energy are compared. The nature of radioactive contamination of areas and of persons resulting from the explosion of nuclear weapons, particularly the relationship between the radiation exposure and the amount of physical debris, is examined. Some theoretical examples are compared quantitatively. It is concluded that the amount of radio-activity that may be carried on the contaminated person involves a minor health hazard from gamma radiation, compared to the irradiation arising from contaminated areas. PMID:6015741

  2. Leachate tests with sewage sludge contaminated by radioactive cesium.

    PubMed

    Tsushima, Ikuo; Ogoshi, Masashi; Harada, Ichiro

    2013-01-01

    The sewer systems of eastern Japan have transported radioactive fallout from the Fukushima Dai-ichi nuclear power plant accident to wastewater treatment plants, where the radioisotopes have accumulated. To better understand the potential problems associated with the disposal of contaminated sewage sludge in landfills, leachate tests were conducted with radioactive incinerator ash, cement solidification incinerator ash, and dewatered sludge cake. Radioactivity was undetectable in the eluate from incinerator ash and dewatered sludge cake, but about 30% of the radioactivity initially in cement solidification incinerator ash appeared in the eluate during the leaching experiments. Moreover, modification of test conditions revealed that the presence of Ca(2+) ions and strong alkali in the water that contacted the incinerator ash enhanced leaching of cesium. Lastly, the capacity of pit soil to absorb radioactive cesium was estimated to be at least 3.0 Bq/g (dry). PMID:23947711

  3. ASSESSMENT OF RADIOACTIVE AND NON-RADIOACTIVE CONTAMINANTS FOUND IN LOW LEVEL RADIOACTIVE WASTE STREAMS

    SciTech Connect

    R.H. Little, P.R. Maul, J.S.S. Penfoldag

    2003-02-27

    This paper describes and presents the findings from two studies undertaken for the European Commission to assess the long-term impact upon the environment and human health of non-radioactive contaminants found in various low level radioactive waste streams. The initial study investigated the application of safety assessment approaches developed for radioactive contaminants to the assessment of nonradioactive contaminants in low level radioactive waste. It demonstrated how disposal limits could be derived for a range of non-radioactive contaminants and generic disposal facilities. The follow-up study used the same approach but undertook more detailed, disposal system specific calculations, assessing the impacts of both the non-radioactive and radioactive contaminants. The calculations undertaken indicated that it is prudent to consider non-radioactive, as well as radioactive contaminants, when assessing the impacts of low level radioactive waste disposal. For some waste streams with relatively low concentrations of radionuclides, the potential post-closure disposal impacts from non-radioactive contaminants can be comparable with the potential radiological impacts. For such waste streams there is therefore an added incentive to explore options for recycling the materials involved wherever possible.

  4. Soil contamination standards for protection of personnel

    SciTech Connect

    Rittmann, P.D.

    1998-04-16

    The objective of this report is to recommend soil contamination levels that will ensure that radionuclide intakes by unprotected workers are likely to give internal doses below selected dose limits during the working year. The three internal dose limits are 1, 100, and 500 mrem per year. In addition, photon, beta, and alpha instrument readings are estimated for these soil concentration limits. Two exposure pathways are considered: the first is inhalation of resuspended dust and the second is ingestion of trace amounts of soil. In addition, radioactive decay and ingrowth of progeny during the year of exposure is included. External dose from the soil contamination is not included because monitoring and control of external exposures is carried out independently from internal exposures, which are the focus of this report. The methods used are similar to those used by Carbaugh and Bihl (1993) to set bioassay criteria for such workers.

  5. Soils: man-caused radioactivity and radiation forecast

    SciTech Connect

    Gablin, Vassily

    2007-07-01

    activity had led to contamination of soil only by artificial radionuclides. But we can view a totality of soil radioactivity factors in the following way. (author)

  6. Decontamination of protective clothing against radioactive contamination.

    PubMed

    Vošahlíková, I; Otáhal, P

    2014-11-01

    The aim of this study is to describe the experimental results of external surface mechanical decontamination of the studied materials forming selected suits. Seven types of personal protective suits declaring protection against radioactive aerosol contamination in different price ranges were selected for decontamination experiments. The outcome of this study is to compare the efficiency of a double-step decontamination process on various personal protective suits against radioactive contamination. A comparison of the decontamination effectiveness for the same type of suit, but for the different chemical mixtures ((140)La in a water-soluble or in a water-insoluble compound), was performed. PMID:25084793

  7. Tracer-level radioactive pilot-scale test of in situ vitrification for the stabilization of contaminated soil sites at ORNL

    SciTech Connect

    Spalding, B.P.; Jacobs, G.K.; Naney, M.T.; Dunbar, N.W.; Tixier, J.S.; Powell, T.D.

    1992-11-01

    A field demonstration of in situ vitrification (ISV) was completed in May 1991, and produced approximately 12 Mg of melted earthen materials containing 12.7 mCi of radioactivity within 500 g of sludge in amodel of an old seepage trench waste disposal unit. Past waste disposal operations at Oak Ridge National Laboratory have left several contaminated seepage sites. In planning for remediation of such sites, ISV technology has been identified as a leading candidate because of the high risks associated with any retrieval option and because of the usual high quality of vitreous waste form. Major isotopes placed in the test trench were {sup 137}Cs and {sup 90}Sr, with lesser amounts of {sup 6O}Co, {sup 241}Am, and {sup 239,240}Pu. A total of 29 MWh of electrical power was delivered to the ground over a 5-day period producing a melt depth of 8.5 ft. During melting, 2.4% of the {sup 137}Cs volatilized from the melt into an off-gas containment hood and was captured quantitatively on a high efficiency particulate air filter. No volatilization of {sup 90}Sr, {sup 241}Am, or {sup 239,240}Pu was detected and > 99.993% retention of these isotopes in the melt was estimated. The use of added rare earth tracers (Ce, La, and Nd), as surrogates for transuranic isotopes, led to estimated melt retentions of >99.9995% during the test. The molten material, composed of the native soil and dolomitic limestone used for filling the test trench, reached a processing temperature of 1500{degrees}C. Standardized leaching procedures using Product Consistency Testing indicated that the ISV product has excellent characteristics relative to other vitreous nuclear waste forms.

  8. Tracer-level radioactive pilot-scale test of in situ vitrification for the stabilization of contaminated soil sites at ORNL

    SciTech Connect

    Spalding, B.P.; Jacobs, G.K.; Naney, M.T. ); Dunbar, N.W. ); Tixier, J.S.; Powell, T.D. )

    1992-11-01

    A field demonstration of in situ vitrification (ISV) was completed in May 1991, and produced approximately 12 Mg of melted earthen materials containing 12.7 mCi of radioactivity within 500 g of sludge in amodel of an old seepage trench waste disposal unit. Past waste disposal operations at Oak Ridge National Laboratory have left several contaminated seepage sites. In planning for remediation of such sites, ISV technology has been identified as a leading candidate because of the high risks associated with any retrieval option and because of the usual high quality of vitreous waste form. Major isotopes placed in the test trench were [sup 137]Cs and [sup 90]Sr, with lesser amounts of [sup 6O]Co, [sup 241]Am, and [sup 239,240]Pu. A total of 29 MWh of electrical power was delivered to the ground over a 5-day period producing a melt depth of 8.5 ft. During melting, 2.4% of the [sup 137]Cs volatilized from the melt into an off-gas containment hood and was captured quantitatively on a high efficiency particulate air filter. No volatilization of [sup 90]Sr, [sup 241]Am, or [sup 239,240]Pu was detected and > 99.993% retention of these isotopes in the melt was estimated. The use of added rare earth tracers (Ce, La, and Nd), as surrogates for transuranic isotopes, led to estimated melt retentions of >99.9995% during the test. The molten material, composed of the native soil and dolomitic limestone used for filling the test trench, reached a processing temperature of 1500[degrees]C. Standardized leaching procedures using Product Consistency Testing indicated that the ISV product has excellent characteristics relative to other vitreous nuclear waste forms.

  9. Waste reduction by separation of contaminated soils during environmental restoration

    SciTech Connect

    Roybal, J.A.; Conway, R.; Galloway, B.; Vinsant, E.; Slavin, P.; Guerin, D.

    1998-06-01

    During cleanup of contaminated sites, Sandia National Laboratories, New Mexico (SNL/NM) frequently encounters soils with low-level radioactive contamination. The contamination is not uniformly distributed, but occurs within areas of clean soil. Because it is difficult to characterize heterogeneously contaminated soils in detail and to excavate such soils precisely using heavy equipment, it is common for large quantities of uncontaminated soil to be removed during excavation of contaminated sites. This practice results in the commingling and disposal of clean and contaminated material as low-level waste (LLW), or possibly low-level mixed waste (LLMW). Until recently, volume reduction of radioactively contaminated soil depended on manual screening and analysis of samples, which is a costly and impractical approach and does not uphold As Low As Reasonably Achievable (ALARA) principles. To reduce the amount of LLW and LLMW generated during the excavation process, SNL/NM is evaluating two alternative technologies. The first of these, the Segmented Gate System (SGS), is an automated system that located and removes gamma-ray emitting radionuclides from a host matrix (soil, sand, dry sludge). The matrix materials is transported by a conveyor to an analyzer/separation system, which segregates the clean and contaminated material based on radionuclide activity level. The SGS was used to process radioactively contaminated soil from the excavation of the Radioactive Waste Landfill. The second technology, Large Area Gamma Spectroscopy (LAGS), utilizes a gamma spec analyzer suspended over a slab upon which soil is spread out to a uniform depth. A counting period of approximately 30 minutes is used to obtain a full-spectrum analysis for the isotopes of interest. The LAGS is being tested on the soil that is being excavated from the Classified Waste Landfill.

  10. TRANSPORT OF LOW-LEVEL RADIOACTIVE SOIL AT DEEP-OCEAN DISPOSAL SITE

    EPA Science Inventory

    Transport studies were conducted to assess ocean disposal of soil contaminated with low-level natural radioisotopes. he experimental approach involved characterization of the soil for parameters affecting transport and fate of radionuclides- Radioactivity was associated with disc...

  11. Remediation of groundwater contaminated with radioactive compounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Both naturally radioactive isotopes and isotopes from man-made sources may appear in groundwater. Depending on the physical and chemical characteristics of the contaminant, different types of treatment methods must be applied to reduce the concentration. The following chapter discusses treatment opt...

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

    SciTech Connect

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

    1990-01-01

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

  13. PROCESS OF DECONTAMINATING MATERIAL CONTAMINATED WITH RADIOACTIVITY

    DOEpatents

    Overholt, D.C.; Peterson, M.D.; Acken, M.F.

    1958-09-16

    A process is described for decontaminating metallic objects, such as stainless steel equipment, which consists in contacting such objects with nltric acid in a concentration of 35 to 60% to remove the major portion of the contamination; and thereafter contacting the partially decontaminated object with a second solution containing up to 20% of alkali metal hydroxide and up to 20% sodium tartrate to remove the remaining radioactive contaminats.

  14. Radioactive contamination incidents involving protective clothing

    SciTech Connect

    Reichelt, R.A.; Clay, M.E.; Eichorst, A.J.

    1998-01-01

    The study focuses on incidents at Department of Energy facilities involving the migration of radioactive contaminants through protective clothing. The authors analyzed 68 occurrence reports for the following factors: (1) type of work, (2) working conditions, (3) type of anti-contamination material; (4) area of body or clothing contaminated; and (5) nature of spread of contamination. A majority of reports identified strenuous work activities such as maintenance, construction, or decontamination and decommissioning projects. The reports also indicated adverse working conditions that included hot and humid or cramped work environments. The type of anti-contamination clothing most often identified was cotton or water-resistant disposable clothing. Most of the reports also indicated contaminants migrating through perspiration-soaked areas, typically in the knees and forearms. On the basis of their survey, the authors recommend the use of improved engineering controls and resilient, breathable, waterproof protective clothing for work in hot, humid, or damp areas where the possibility of prolonged contact with contamination cannot be easily avoided or controlled. 1 ref., 6 figs., 1 tab.

  15. Radioactive contamination incidents involving protective clothing.

    PubMed

    Reichelt, R A; Clay, M E; Eichorst, A J

    1998-01-01

    The study focuses on incidents at Department of Energy facilities involving the migration of radioactive contaminants through protective clothing. The authors analyzed 68 occurrence reports for the following factors: (1) type of work; (2) working conditions; (3) type of anti-contamination material; (4) area of body or clothing contaminated; and (5) nature of spread of contamination. A majority of reports identified strenuous work activities such as maintenance, construction, or decontamination and decommissioning projects. The reports also indicated adverse working conditions that included hot and humid or cramped work environments. The type of anti-contamination clothing most often identified was cotton or water-resistant disposable clothing. Most of the reports also indicated contaminants migrating through perspiration-soaked areas, typically in the knees and forearms. On the basis of their survey, the authors recommend the use of improved engineering controls and resilient, breathable, waterproof protective clothing for work in hot, humid, or damp areas where the possibility of prolonged contact with contamination cannot be easily avoided or controlled. PMID:9415588

  16. Radioactive contamination incidents involving protective clothing

    SciTech Connect

    Reichelt, R.; Clay, M.; Eichorst, J.

    1996-10-01

    The study focuses on incidents at Department of Energy (DOE) facilities involving the migration of radioactive contaminants through protective clothing. The authors analyzed 68 occurrence reports for the following factors: (1) type of work; (2) working conditions; (3) type of anti-contamination (anti-C) material; (4) area of body or clothing contaminated; and (5) nature of spread of contamination. A majority of reports identified strenuous work activities such as maintenance, construction, or decontamination and decommissioning (D&D) projects. The reports also indicated adverse working conditions that included hot and humid or cramped work environments. The type of anti-C clothing most often identified was cotton or water-resistant, disposable clothing. Most of the reports also indicated contaminants migrating through perspiration-soaked areas, typically in the knees and forearms. On the basis of their survey, the authors recommend the use of improved engineering controls and resilient, breathable, waterproof protective clothing for work in hot, humid, or damp areas where the possibility of prolonged contact with contamination cannot be easily avoided or controlled.

  17. [Decorporation agents for internal radioactive contamination].

    PubMed

    Ohmachi, Yasushi

    2015-01-01

    When radionuclides are accidentally ingested or inhaled, blood circulation or tissue/organ deposition of the radionuclides causes systemic or local radiation effects. In such cases, decorporation therapy is used to reduce the health risks due to their intake. Decorporation therapy includes reduction and/or inhibition of absorption from the gastrointestinal tract, isotopic dilution, and the use of diuretics, adsorbents, and chelating agents. For example, penicillamine is recommended as a chelating agent for copper contamination, and diethylene triamine pentaacetic acid is approved for the treatment of internal contamination with plutonium. During chelation therapy, the removal effect of the drugs should be monitored using a whole-body counter and/or bioassay. Some authorities, such as the National Council on Radiation Protection and Measurements and International Atomic Energy Agency, have reported recommended decorporation agents for each radionuclide. However, few drugs are approved by the US Food and Drug Administration, and many are off-label-use agents. Because many decontamination agents are drugs that have been available for a long time and have limited efficacy, the development of new, higher-efficacy drugs has been carried out mainly in the USA and France. In this article, in addition to an outline of decorporation agents for internal radioactive contamination, an outline of our research on decorporation agents for actinide (uranium and plutonium) contamination and for radio-cesium contamination is also presented. PMID:25832835

  18. BIOREMEDIATION OF CONTAMINATED SURFACE SOILS

    EPA Science Inventory

    Biological remediation of soils contaminated with organic chemicals is an alternative treatment technology that can often meet the goal of achieving a permanent clean-up remedy at hazardous waste sites, as encouraged by the U.S. Environmental Protection Agency (U.S. EPA) for impl...

  19. Biotreatment of explosive contaminated soils

    SciTech Connect

    Shen, C.F.; Guiot, S.R.; Manuel, M.F.

    1995-12-31

    The aim of this research was to develop a process which can be employed to remediate 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) contaminated soils. The TNT and RDX degrading ability of microorganisms in municipal activated sludge and anaerobic sludge was evaluated, along with the toxicity of TNT and RDX to the microorganisms under aerobic and anaerobic conditions. Biotreatment of TNT and RDX contaminated soils was studied in bioslurry reactors. Microcosm tests were also conducted to see if TNT and RDX removal from the slurry reactor is attributed to a mineralization to CO{sub 2}, and to determine the synergetic or antagonistic effct (if any) of TNT and RDX on the mineralization. Both sludge types were found to be rich sources of RDX degrading organisms. The supplement of anaerobic sludge in bioslurry reactor enhances the biodegradation of TNT and RDX, and leads to complete removal of TNT and RDX from the contaminated soil. Bioslurry reactors may be a cost-effective approach to the on-site bioremediation of soils contaminated with high levels of epxlosives.

  20. Metagenomic analysis of microbial community in uranium-contaminated soil.

    PubMed

    Yan, Xun; Luo, Xuegang; Zhao, Min

    2016-01-01

    Uranium tailing is a serious pollution challenge for the environment. Based on metagenomic sequencing analysis, we explored the functional and structural diversity of the microbial community in six soil samples taken at different soil depths from uranium-contaminated and uncontaminated areas. Kyoto Encyclopedia of Genes and Genomes Orthology (KO) groups were obtained using a Basic Local Alignment Search Tool search based on the universal protein resource database. The KO-pathway network was then constructed using the selected KOs. Finally, alpha and beta diversity analyses were performed to explore the differences in soil bacterial diversity between the radioactive soil and uncontaminated soil. In total, 30-68 million high-quality reads were obtained. Sequence assembly yielded 286,615 contigs; and these contigs mostly annotated to 1699 KOs. The KO distributions were similar among the six soil samples. Moreover, the proportion of the metabolism of other amino acids (e.g., beta-alanine, taurine, and hypotaurine) and signal transduction was significantly lower in radioactive soil than in uncontaminated soil, whereas the proportion of membrane transport and carbohydrate metabolism was higher. Additionally, KOs were mostly enriched in ATP-binding cassette transporters and two-component systems. According to diversity analyses, Actinobacteria and Proteobacteria were the dominant phyla in radioactive and uncontaminated soil, and Robiginitalea, Microlunatus, and Alicyclobacillus were the dominant genera in radioactive soil. Taken together, these results demonstrate that soil microbial community, structure, and functions show significant changes in uranium-contaminated soil. The dominant categories such as Actinobacteria and Proteobacteria may be applied in environmental governance for uranium-contaminated soil in southern China. PMID:26433967

  1. Method of treating radioactively contaminated solvent waste

    SciTech Connect

    Jablonski, W.; Mallek, H.; Plum, W.

    1981-07-07

    A method of and apparatus for treating radioactively contaminated solvent waste are claimed. The solvent waste is supplied to material such as peat, vermiculite, diaton, etc. This material effects the distribution or dispersion of the solvent and absorbs the foreign substances found in the solvent waste. Air or an inert gas flows through the material in order to pick up the solvent portions which are volatile as a consequence of their vapor pressure. The thus formed gas mixture, which includes air or inert gas and solvent portions, is purified in a known manner by thermal, electrical, or catalytic combustion of the solvent portions.

  2. 10 CFR 39.69 - Radioactive contamination control.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Radioactive contamination control. 39.69 Section 39.69... Radiation Safety Requirements § 39.69 Radioactive contamination control. (a) If the licensee detects evidence that a sealed source has ruptured or licensed materials have caused contamination, the...

  3. 10 CFR 39.69 - Radioactive contamination control.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Radioactive contamination control. 39.69 Section 39.69... Radiation Safety Requirements § 39.69 Radioactive contamination control. (a) If the licensee detects evidence that a sealed source has ruptured or licensed materials have caused contamination, the...

  4. 10 CFR 39.69 - Radioactive contamination control.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Radioactive contamination control. 39.69 Section 39.69... Radiation Safety Requirements § 39.69 Radioactive contamination control. (a) If the licensee detects evidence that a sealed source has ruptured or licensed materials have caused contamination, the...

  5. 10 CFR 39.69 - Radioactive contamination control.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Radioactive contamination control. 39.69 Section 39.69... Radiation Safety Requirements § 39.69 Radioactive contamination control. (a) If the licensee detects evidence that a sealed source has ruptured or licensed materials have caused contamination, the...

  6. 10 CFR 39.69 - Radioactive contamination control.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Radioactive contamination control. 39.69 Section 39.69... Radiation Safety Requirements § 39.69 Radioactive contamination control. (a) If the licensee detects evidence that a sealed source has ruptured or licensed materials have caused contamination, the...

  7. Testing contaminated soil

    SciTech Connect

    McKenna, J.; Pickering, E.

    1995-11-01

    Today`s environmental projects involve a variety of complex issues that property owners and environmental professionals have to consider before they embark on a site-remediation program. One of the key things that has to be done during a project is to understand and select the chemical analysis parameters (CAPs) that are needed to characterize the soil. For instance, site investigations to determine if a soil is polluted require engineers to carefully select CAPs that will yield this information. Offsite fusibilities that specialize in waste treatment and disposal, on the other hand, require CAPs that may vary greatly from the CAPs needed for site investigations. However, when offsite treatment and disposal is the preferred remedial option, one can save money and add value to a project by including the CAPs required by a treatment, storage and disposal (TSD) facility to those CAPs selected for the site investigation. To select the right combination of CAPs to cover both site investigations and treatment and disposal requires a clear understanding of the analytical methods underlying the CAPs. The following set of CAPs are typically required by RCRA and non-RCRA TSD facilities: Total petroleum hydrocarbons; EPA method 9045 for corrosivities (pH); Reactivity; Total RCRA-8 metals; EPA Method 8240 for volatile organic compounds; EPA Method 8270 for semi-volatile organic compounds (SVOCs); EPA Method 8080 for polychlorinated biphenyls (PCBs); EPA Method 1010 for ignitability. These are all described.

  8. The optimisation of electrokinetic remediation for heavy metals and radioactivity contamination on Holyrood-Lunas soil (acrisol species) in Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia.

    PubMed

    Mohamed Johar, S; Embong, Z

    2015-11-01

    The optimisation of electrokinetic remediation of an alluvial soil, locally named as Holyrood-Lunas from Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia, had been conducted in this research. This particular soil was chosen due to its relatively high level of background radiation in a range between 139.2 and 539.4 nGy h(-1). As the background radiation is correlated to the amount of parent nuclides, (238)U and (232)Th, hence, a remediation technique, such as electrokinetic, is very useful in reducing these particular concentrations of heavy metal and radionuclides in soils. Several series of electrokinetics experiments were performed in laboratory scale in order to study the influence of certain electrokinetic parameters in soil. The concentration before (pre-electrokinetic) and after the experiment (post-electrokinetic) was determined via X-ray fluorescence (XRF) analysis technique. The best electrokinetic parameter that contributed to the highest achievable concentration removal of heavy metals and radionuclides on each experimental series was incorporated into a final electrokinetic experiment. Here, High Pure Germanium (HPGe) was used for radioactivity elemental analysis. The XRF results suggested that the most optimised electrokinetic parameters for Cr, Ni, Zn, As, Pb, Th and U were 3.0 h, 90 volts, 22.0 cm, plate-shaped electrode by 8 × 8 cm and in 1-D configuration order whereas the selected optimised electrokinetic parameters gave very low reduction of (238)U and (232)Th at 0.23 ± 2.64 and 2.74 ± 23.78 ppm, respectively. PMID:25920778

  9. The total amounts of radioactively contaminated materials in forests in Fukushima, Japan.

    PubMed

    Hashimoto, Shoji; Ugawa, Shin; Nanko, Kazuki; Shichi, Koji

    2012-01-01

    There has been leakage of radioactive materials from the Fukushima Daiichi Nuclear Power Plant. A heavily contaminated area (≥ ¹³⁴,¹³⁷Cs 1000 kBq m⁻²) has been identified in the area northwest of the plant. The majority of the land in the contaminated area is forest. Here we report the amounts of biomass, litter (small organic matter on the surface of the soil), coarse woody litter, and soil in the contaminated forest area. The estimated overall volume and weight were 33 Mm³ (branches, leaves, litter, and coarse woody litter are not included) and 21 Tg (dry matter), respectively. Our results suggest that removing litter is an efficient method of decontamination. However, litter is being continuously decomposed, and contaminated leaves will continue to fall on the soil surface for several years; hence, the litter should be removed promptly but continuously before more radioactive elements are transferred into the soil. PMID:22639724

  10. The total amounts of radioactively contaminated materials in forests in Fukushima, Japan

    PubMed Central

    Hashimoto, Shoji; Ugawa, Shin; Nanko, Kazuki; Shichi, Koji

    2012-01-01

    There has been leakage of radioactive materials from the Fukushima Daiichi Nuclear Power Plant. A heavily contaminated area (≥ 134, 137Cs 1000 kBq m−2) has been identified in the area northwest of the plant. The majority of the land in the contaminated area is forest. Here we report the amounts of biomass, litter (small organic matter on the surface of the soil), coarse woody litter, and soil in the contaminated forest area. The estimated overall volume and weight were 33 Mm3 (branches, leaves, litter, and coarse woody litter are not included) and 21 Tg (dry matter), respectively. Our results suggest that removing litter is an efficient method of decontamination. However, litter is being continuously decomposed, and contaminated leaves will continue to fall on the soil surface for several years; hence, the litter should be removed promptly but continuously before more radioactive elements are transferred into the soil. PMID:22639724

  11. Contaminant resorption during soil washing

    SciTech Connect

    Gombert, D.

    1993-10-01

    To evaluate the applicability of soil washing to a specific site requires some basic research in how contaminants are bound. Much can be learned from sequential extraction methodology based on micronutrient bioavailability studies wherein the soil matrix is chemically dissected to selectively remove particular fixation mechanisms independently. This procedure uses a series of progressively more aggressive solvents to dissolve the principle phases that make up a soil, however, the published studies do not appear to consider the potential for a contaminant released from one type of site to resorb on another site during an extraction. This physical model assumes no ion exchange or adsorption at sites either previously occupied by other ions, or exposed by the dissolution. Therefore, to make engineering use of the sequential extraction data, the release of contamination must be evaluated relative to the effects of resorption. Time release studies were conducted to determine the optimum duration for extraction to maximize complete destruction of the target matrix fraction while minimizing contaminant resorption. Tests with and without a potassium brine present to inhibit cesium resorption indicated extraction efficiency could be enhanced by as much as a factor of ten using the brine.

  12. Packaging and transportation of radioactively contaminated lead

    SciTech Connect

    Gleason, Eugene; Holden, Gerard

    2007-07-01

    Under the management of the Nuclear Decommissioning Authority (NDA) the government of the United Kingdom has launched an ambitious program to remediate the nation's nuclear waste legacy. Over a twenty-five year period NDA plans to decommission several first generation nuclear power plants and other radioactive facilities. The use innovative, safe 'fit for purpose' technologies will be a major part of this complex program. This paper will present a case study of a recently completed project undertaken in support of the nuclear decommissioning activities at the Sellafield site in the United Kingdom. The focus is on an innovative application of new packaging technology developed for the safe transportation of radioactively contaminated lead objects. Several companies collaborated on the project and contributed to its safe and successful conclusion. These companies include British Nuclear Group, Gravatom Engineering, W. F. Bowker Transport, Atlantic Container Lines, MHF Logistical Solutions and Energy Solutions. New containers and a new innovative inter-modal packaging system to transport the radioactive lead were developed and demonstrated during the project. The project also demonstrated the potential contribution of international nuclear recycling activities as a safe, economic and feasible technical option for nuclear decommissioning in the United Kingdom. (authors)

  13. Procedures for sampling radium-contaminated soils

    SciTech Connect

    Fleischhauer, H.L.

    1985-10-01

    Two procedures for sampling the surface layer (0 to 15 centimeters) of radium-contaminated soil are recommended for use in remedial action projects. Both procedures adhere to the philosophy that soil samples should have constant geometry and constant volume in order to ensure uniformity. In the first procedure, a ''cookie cutter'' fashioned from pipe or steel plate, is driven to the desired depth by means of a slide hammer, and the sample extracted as a core or plug. The second procedure requires use of a template to outline the sampling area, from which the sample is obtained using a trowel or spoon. Sampling to the desired depth must then be performed incrementally. Selection of one procedure over the other is governed primarily by soil conditions, the cookie cutter being effective in nongravelly soils, and the template procedure appropriate for use in both gravelly and nongravelly soils. In any event, a minimum sample volume of 1000 cubic centimeters is recommended. The step-by-step procedures are accompanied by a description of the minimum requirements for sample documentation. Transport of the soil samples from the field is then addressed in a discussion of the federal regulations for shipping radioactive materials. Interpretation of those regulations, particularly in light of their application to remedial action soil-sampling programs, is provided in the form of guidance and suggested procedures. Due to the complex nature of the regulations, however, there is no guarantee that our interpretations of them are complete or entirely accurate. Preparation of soil samples for radium-226 analysis by means of gamma-ray spectroscopy is described.

  14. Radioactivity in the industrial effluent disposed soil

    NASA Astrophysics Data System (ADS)

    Senthilkumar, R. D.; Narayanaswamy, R.; Meenashisundaram, V.

    2012-04-01

    Studies on radiation and radioactivity distribution in the soils of effluent disposed from the sugar industry in India have been conducted. The external gamma dose rates in air and natural radionuclides activities in the soils were measured using an Environmental Radiation Dosimeter and a Gamma-ray Spectrometer respectively. The soil samples were also subject to various physico-chemical analyses. This study revealed some remarkable results that are discussed in the article.

  15. Phytoremediation of Metal-Contaminated Soils

    SciTech Connect

    Shtangeeva, I.; Laiho, J.V-P.; Kahelin, H.; Gobran, G.R.

    2004-03-31

    Recent concerns regarding environmental contamination have necessitated the development of appropriate technologies to assess the presence and mobility of metals in soil and estimate possible ways to decrease the level of soil metal contamination. Phytoremediation is an emerging technology that may be used to cleanup contaminated soils. Successful application of phytoremediation, however, depends upon various factors that must be carefully investigated and properly considered for specific site conditions. To efficiently affect the metal removal from contaminated soils we used the ability of plants to accumulate different metals and agricultural practices to improve soil quality and enhance plant biomass. Pot experiments were conducted to study metal transport through bulk soil to the rhizosphere and stimulate transfer of the metals to be more available for plants' form. The aim of the experimental study was also to find fertilizers that could enhance uptake of metals and their removal from contaminated soil.

  16. [Heterogeneity of parasitic contamination of megalopolis soils].

    PubMed

    Aliautdinova, L V; Semenova, T A; Zavoĭkin, V D

    2011-01-01

    A morphological group ofwhipworm (Trichuris trichiura) eggs, which is detectable in the soil samples from the city's different control lands, shows that their origin is heterogeneous and it is possible to differentiate them by morphometric signs. At the same time is necessary to consider the specific biological factors contributing to soil contamination. Priority in parasitic soil contamination should be given to animals, dogs in particular, which is supported by the fact that the dog walking grounds exhibit the highest contamination rates. PMID:21797059

  17. The Accumulation of Radioactive Contaminants in Drinking Water Distribution Systems

    EPA Science Inventory

    The accumulation of trace contaminants in drinking water distribution systems has been documented and the subsequent release of the contaminants back to the water is a potential exposure pathway. Radioactive contaminants are of particular concern because of their known health eff...

  18. Phytoremediation of Soils Contaminated by Chlorinnated Hydrocarbons

    NASA Astrophysics Data System (ADS)

    Cho, C.; Sung, K.; Corapcioglu, M.

    2001-12-01

    In recent years, the possible use of deep rooted plants for phytoremediation of soil contaminants has been offered as a potential alternative for waste management, particularly for in situ remediation of large volumes of contaminated soils. Major objectives of this study are to evaluate the effectiveness of a warm season grass (Eastern Gamagrass) and a cool season prairie grass (Annual Ryegrass) in the phytoremediation of the soil contaminated with volatile organic compounds e.g., trichloroethylene (TCE), tetrachloroethylene (PCE), and 1,1,1-trichloroethane (TCA) and to determine the main mechanisms of target contaminant dissipation. The preliminary tests and laboratory scale tests were conducted to identify the main mechanisms for phytoremediation of the target contaminants, and to apply the technique in green house application under field conditions. The results of microcosm and bioreactor experiments showed that volatilization can be the dominant pathway of the target contaminant mass losses in soils. Toxicity tests, conducted in nutrient solution in the growth room, and in the greenhouse, showed that both Eastern gamagrass and Annual ryegrass could grow without harmful effects at up to 400 ppm each of all three contaminants together. Preliminary greenhouse experimentw were conducted with the 1.5 m long and 0.3 m diameter PVC columns. Soil gas concentrations monitored and microbial biomass in bulk and rhizosphere soil, root properties, and contaminant concentration in soil after 100 days were analyzed. The results showed that the soil gas concentration of contaminants has rapidly decreased especially in the upper soil and the contaminant concentraitons in soil were also significantly decreased to 0.024, 0.228, and 0.002 of C/Co for TCE, PCE and TCA, respectively. Significant plant effects were not found however showed contaminant loss through volatilization and plant contamination by air.

  19. Highly reduced mass loss rates and increased litter layer in radioactively contaminated areas.

    PubMed

    Mousseau, Timothy A; Milinevsky, Gennadi; Kenney-Hunt, Jane; Møller, Anders Pape

    2014-05-01

    The effects of radioactive contamination from Chernobyl on decomposition of plant material still remain unknown. We predicted that decomposition rate would be reduced in the most contaminated sites due to an absence or reduced densities of soil invertebrates. If microorganisms were the main agents responsible for decomposition, exclusion of large soil invertebrates should not affect decomposition. In September 2007 we deposited 572 bags with uncontaminated dry leaf litter from four species of trees in the leaf litter layer at 20 forest sites around Chernobyl that varied in background radiation by more than a factor 2,600. Approximately one quarter of these bags were made of a fine mesh that prevented access to litter by soil invertebrates. These bags were retrieved in June 2008, dried and weighed to estimate litter mass loss. Litter mass loss was 40% lower in the most contaminated sites relative to sites with a normal background radiation level for Ukraine. Similar reductions in litter mass loss were estimated for individual litter bags, litter bags at different sites, and differences between litter bags at pairs of neighboring sites differing in level of radioactive contamination. Litter mass loss was slightly greater in the presence of large soil invertebrates than in their absence. The thickness of the forest floor increased with the level of radiation and decreased with proportional loss of mass from all litter bags. These findings suggest that radioactive contamination has reduced the rate of litter mass loss, increased accumulation of litter, and affected growth conditions for plants. PMID:24590204

  20. SOIL WASHING TREATABILITY TESTS FOR PESTICIDE- CONTAMINATED SOIL

    EPA Science Inventory

    The 1987 Sand Creek Operable Unit 5 record of decision (ROD) identified soil washing as the selected technology to remediate soils contaminated with high levels of organochlorine pesticides, herbicides, and metals. Initial treatability tests conducted to assess the applicability...

  1. Surfactants treatment of crude oil contaminated soils.

    PubMed

    Urum, Kingsley; Pekdemir, Turgay; Copur, Mehmet

    2004-08-15

    This study reports experimental measurements investigating the ability of a biological (rhamnolipid) and a synthetic (sodium dodecyl sulfate, SDS) surfactant to remove the North Sea Ekofisk crude oil from various soils with different particle size fractions under varying washing conditions. The washing parameters and ranges tested were as follows: temperature (5 to 50 degrees C), time (5 to 20 min), shaking speed (80 to 200 strokes/min), volume (5 to 20 cm3), and surfactant concentration (0.004 to 5 mass%). The contaminated soils were prepared in the laboratory by mixing crude oil and soils using a rotating cylindrical mixer. Two contamination cases were considered: (1) weathered contamination was simulated by keeping freshly contaminated soils in a fan assisted oven at 50 degrees C for 14 days, mimicking the weathering effect in a natural hot environment, and (2) nonweathered contamination which was not subjected to the oven treatment. The surfactants were found to have considerable potential in removing crude oil from different contaminated soils and the results were comparable with those reported in literature for petroleum hydrocarbons. The removal of crude oil with either rhamnolipid or SDS was within the repeatability range of +/-6%. The most influential parameters on oil removal were surfactant concentration and washing temperature. The soil cation exchange capacity and pH also influenced the removal of crude oil from the individual soils. However, due to the binding of crude oil to soil during weathering, low crude oil removal was achieved with the weathered contaminated soil samples. PMID:15271574

  2. RESRAD: A computer code for evaluating radioactively contaminated sites

    SciTech Connect

    Yu, C.; Zielen, A.J.; Cheng, J.J.

    1993-12-31

    This document briefly describes the uses of the RESRAD computer code in calculating site-specific residual radioactive material guidelines and radiation dose-risk to an on-site individual (worker or resident) at a radioactively contaminated site. The adoption by the DOE in order 5400.5, pathway analysis methods, computer requirements, data display, the inclusion of chemical contaminants, benchmarking efforts, and supplemental information sources are all described. (GHH)

  3. In situ removal of contamination from soil

    DOEpatents

    Lindgren, E.R.; Brady, P.V.

    1997-10-14

    A process of remediation of cationic heavy metal contamination from soil utilizes gas phase manipulation to inhibit biodegradation of a chelating agent that is used in an electrokinesis process to remove the contamination. The process also uses further gas phase manipulation to stimulate biodegradation of the chelating agent after the contamination has been removed. The process ensures that the chelating agent is not attacked by bioorganisms in the soil prior to removal of the contamination, and that the chelating agent does not remain as a new contaminant after the process is completed. 5 figs.

  4. In situ removal of contamination from soil

    DOEpatents

    Lindgren, Eric R.; Brady, Patrick V.

    1997-01-01

    A process of remediation of cationic heavy metal contamination from soil utilizes gas phase manipulation to inhibit biodegradation of a chelating agent that is used in an electrokinesis process to remove the contamination, and further gas phase manipulation to stimulate biodegradation of the chelating agent after the contamination has been removed. The process ensures that the chelating agent is not attacked by bioorganisms in the soil prior to removal of the contamination, and that the chelating agent does not remain as a new contaminant after the process is completed.

  5. Vitrification testing of soil fines from contaminated Hanford 100 Area and 300 Area soils

    SciTech Connect

    Ludowise, J.D.

    1994-05-01

    The suitability of Hanford soil for vitrification is well known and has been demonstrated extensively in other work. The tests reported here were carried out to confirm the applicability of vitrification to the soil fines (a subset of the Hanford soil potentially different in composition from the bulk soil) and to provide data on the performance of actual, vitrified soil fines. It was determined that the soil fines were generally similar in composition to the bulk Hanford soil, although the fraction <0.25 mm in the 100 Area soil sample appears to differ somewhat from the bulk soil composition. The soil fines are readily melted into a homogeneous glass with the simple additions of CaO and/or Na{sub 2}O. The vitrified waste (plus additives) occupies only 60% of the volume of the initial untreated waste. Leach testing has shown the glasses made from the soil fines to be very durable relative to natural and man-made glasses and has demonstrated the ability of the vitrified waste to greatly reduce the release of radionuclides to the environment. Viscosity and electrical conductivity measurements indicate that the soil fines will be readily processable, although with levels of additives slightly greater than used in the radioactive melts. These tests demonstrate the applicability of vitrification to the contaminated soil fines and the exceptional performance of the waste form resulting from the vitrification of contaminated Hanford soils.

  6. 14. Protective measures for activities in Chernobyl's radioactively contaminated territories.

    PubMed

    Nesterenko, Alexey V; Nesterenko, Vassily B

    2009-11-01

    Owing to internally absorbed radionuclides, radiation levels for individuals living in the contaminated territories of Belarus, Ukraine, and Russia have been increasing steadily since 1994. Special protective measures in connection with agriculture, forestry, hunting, and fishing are necessary to protect the health of people in all the radioactively contaminated territories. Among the measures that have proven to be effective in reducing levels of incorporated radionuclides in meat production are food additives with ferrocyanides, zeolites, and mineral salts. Significant decreases in radionuclide levels in crops are achieved using lime/Ca as an antagonist of Sr-90, K fertilizers as antagonists of Cs-137, and phosphoric fertilizers that form a hard, soluble phosphate with Sr-90. Disk tillage and replowing of hayfields incorporating applications of organic and mineral fertilizers reduces the levels of Cs-137 and Sr-90 three- to fivefold in herbage grown in mineral soils. Among food technologies to reduce radionuclide content are cleaning cereal seeds, processing potatoes into starch, processing carbohydrate-containing products into sugars, and processing milk into cream and butter. There are several simple cooking techniques that decrease radionuclides in foodstuffs. Belarus has effectively used some forestry operations to create "a live partition wall," to regulate the redistribution of radionuclides into ecosystems. All such protective measures will be necessary in many European territories for many generations. PMID:20002058

  7. Bioremediation of PAH contaminated soil samples

    SciTech Connect

    Joshi, M.M.; Lee, S.

    1994-12-31

    Soils contaminated with polynuclear aromatic hydrocarbons (PAHs) pose a hazard to life. The remediation of such sites can be done using physical, chemical, and biological treatment methods or a combination of them. It is of interest to study the decontamination of soil using bioremediation. The experiments were conducted using Acinetobacter (ATCC 31012) at room temperature without pH or temperature control. In the first series of experiments, contaminated soil samples obtained from Alberta Research Council were analyzed to determine the toxic contaminant and their composition in the soil. These samples were then treated using aerobic fermentation and removal efficiency for each contaminant was determined. In the second series of experiments, a single contaminant was used to prepare a synthetic soil sample. This sample of known composition was then treated using aerobic fermentation in continuously stirred flasks. In one set of flasks, contaminant was the only carbon source and in the other set, starch was an additional carbon source. In the third series of experiments, the synthetic contaminated soil sample was treated in continuously stirred flasks in the first set and in fixed bed in the second set and the removal efficiencies were compared. The removal efficiencies obtained indicated the extent of biodegradation for various contaminants, the effect of additional carbon source, and performance in fixed bed without external aeration.

  8. Restoration of water environment contaminated by radioactive cesium released from Fukushima Daiichi NPP

    SciTech Connect

    Takeshita, K.; Takahashi, H.; Jinbo, Y.; Ishido, A.

    2013-07-01

    In the Fukushima Daiichi NPP Accident, large amounts of volatile radioactive nuclides, such as {sup 131}I, {sup 134}Cs and {sup 137}Cs, were released to the atmosphere and huge areas surrounding the nuclear site were contaminated by the radioactive fallout. In this study, a combined process with a hydrothermal process and a coagulation settling process was proposed for the separation of radioactive Cs from contaminated soil and sewage sludge. The coagulation settling operation uses Prussian Blue (Ferric ferrocyanide) and an inorganic coagulant. The recovery of Cs from sewage sludge sampled at Fukushima city (100.000 Bq/kg) and soil at a nearby village (55.000 Bq/kg), was tested. About 96% of Cs in the sewage sludge was removed successfully by combining simple hydrothermal decomposition and coagulation settling. However, Cs in the soil was not removed sufficiently by the combined process (Cs removal is only 56%). The hydrothermal decomposition with blasting was carried out. The Cs removal from the soil was increased to 85%. When these operations were repeated twice, the Cs recovery was over 90%. The combined process with hydrothermal blasting and coagulation settling is applicable to the removal of Cs from highly contaminated soil.

  9. A petroleum contaminated soil bioremediation facility

    SciTech Connect

    Lombard, K.; Hazen, T.

    1994-06-01

    The amount of petroleum contaminated soil (PCS) at the Savannah River site (SRS) that has been identified, excavated and is currently in storage has increased several fold during the last few years. Several factors have contributed to this problem: (1) South Carolina Department of Health ad Environmental control (SCDHEC) lowered the sanitary landfill maximum concentration for total petroleum hydrocarbons (TPH) in the soil from 500 to 100 parts per million (ppm), (2) removal and replacement of underground storage tanks at several sites, (3) most recently SCDHEC disallowed aeration for treatment of contaminated soil, and (4) discovery of several very large contaminated areas of soil associated with leaking underground storage tanks (LUST), leaking pipes, disposal areas, and spills. Thus, SRS has an urgent need to remediate large quantities of contaminated soil that are currently stockpiled and the anticipated contaminated soils to be generated from accidental spills. As long as we utilize petroleum based compounds at the site, we will continue to generate contaminated soil that will require remediation.

  10. Remediation of transuranic-contaminated coral soil at Johnston Atoll using the segmented gate system

    SciTech Connect

    Bramlitt, E.; Johnson, N.

    1994-12-31

    Thermo Analytical, Inc. (TMA) has developed a system to remove clean soil from contaminated soil. The system consists of a soil conveyor, an array of radiation detectors toward the conveyor feed end, a gate assembly at the conveyor discharge end, and two additional conveyors which move discharged soil to one or another paths. The gate assembly is as wide as the ``sorter conveyor,`` and it has eight individual gates or segments. The segments automatically open or close depending on the amount of radioactivity present. In one position they pass soil to a clean soil conveyor, and in the other position they let soil fall to a hot soil conveyor. The soil sorting process recovers clean soil for beneficial use and it substantially reduces the quantity of soil which must be decontaminated or prepared for waste disposal. The Segmented Gate System (SGS) was developed for the cleanup of soil contaminated with some transuranium elements at Johnston Atoll. It has proven to be an effective means for recovering clean soil and verifying that soil is clean, minimizing the quantity of truly contaminated soil, and providing measures of contamination for waste transport and disposal. TMA is constructing a small, transportable soil cleanup as it is confident the SGS technology can be adapted to soils and contaminants other than those at Johnston Atoll. It will use this transportable plant to demonstrate the technology and to develop site specific parameters for use in designing plants to meet cleanup needs.

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

    SciTech Connect

    Jones, S.C.

    1997-06-01

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

  12. Soil Vapor Extraction of PCE/TCE Contaminated Soil

    SciTech Connect

    Bradley, J.M.; Morgenstern, M.R.

    1998-08-01

    The A/M Area of the Savannah River Site soil and groundwater is contaminated with tetrachloroethylene (PCE) and trichloroethylene (TCE). Contamination is the result of previous waste disposal practices, once considered state-of-the-art. Soil Vapor Extraction (SVE) units have been installed to remediate the A/M Area vadose zone. SVE is a proven in-situ method for removing volatile organics from a soil matrix with minimal site disturbance. SVE alleviates the infiltration of contaminants into the groundwater and reduces the total time required for groundwater remediation. Lessons learned and optimization of the SVE units are also discussed.

  13. Activated Natural Zeolites on Textiles: Protection from Radioactive Contamination

    NASA Astrophysics Data System (ADS)

    Grancaric, A. M.; Prlic, I.; Tarbuk, A.; Marovic, G.

    Clothing designed to protect against radioactive contamination was based on a simple principle. It was important not to inhale contaminated dust and air and to ensure that contaminated particles could not reach the skin. Therefore, the density of the textile was crucial. New developments, keeping in mind that textile should be lightweight, are focused on textiles which can chemically bind the contamination particles and not allow them either to diffuse to the skin or spread back into the environment. A great success would be if the clothing were made reusable (e.g., for use in the space station). Therefore, new methods (or chemical preparations) are being proposed for developing intelligent textiles.

  14. Treatment of NORM contaminated soil from the oilfields.

    PubMed

    Abdellah, W M; Al-Masri, M S

    2014-03-01

    Uncontrolled disposal of oilfield produced water in the surrounding environment could lead to soil contamination by naturally occurring radioactive materials (NORM). Large volumes of soil become highly contaminated with radium isotopes ((226)Ra and (228)Ra). In the present work, laboratory experiments have been conducted to reduce the activity concentration of (226)Ra in soil. Two techniques were used, namely mechanical separation and chemical treatment. Screening of contaminated soil using vibratory sieve shaker was performed to evaluate the feasibility of particle size separation. The fractions obtained were ranged from less than 38 μm to higher than 300 μm. The results show that (226)Ra activity concentrations vary widely from fraction to fraction. On the other hand, leaching of (226)Ra from soil by aqueous solutions (distilled water, mineral acids, alkaline medias and selective solvents) has been performed. In most cases, relatively low concentrations of radium were transferred to solutions, which indicates that only small portions of radium are present on the surface of soil particles (around 4.6%), while most radium located within soil particles; only concentrated nitric acid was most effective where 50% of (226)Ra was removed to aqueous phase. However, mechanical method was found to be easy and effective, taking into account safety procedures to be followed during the implementation of the blending and homogenization. Chemical extraction methods were found to be less effective. The results obtained in this study can be utilized to approach the final option for disposal of NORM contaminated soil in the oilfields. PMID:24378731

  15. Emergency department management of patients internally contaminated with radioactive material.

    PubMed

    Kazzi, Ziad; Buzzell, Jennifer; Bertelli, Luiz; Christensen, Doran

    2015-02-01

    After a radiation emergency that involves the dispersal of radioactive material, patients can become externally and internally contaminated with 1 or more radionuclides. Internal contamination can lead to the delivery of harmful ionizing radiation doses to various organs and tissues or the whole body. The clinical consequences can range from acute radiation syndrome to the long-term development of cancer. Estimating the amount of radioactive material absorbed into the body can guide the management of patients. Treatment includes, in addition to supportive care and long term monitoring, certain medical countermeasures like Prussian blue, calcium diethylenetriamine pentaacetic acid (DTPA) and zinc DTPA. PMID:25455668

  16. Emergency department management of patients internally contaminated with radioactive material

    DOE PAGESBeta

    Kazzi, Ziad; Buzzell, Jennifer; Bertelli, Luiz; Christensen, Doran

    2014-11-15

    After a radiation emergency that involves the dispersal of radioactive material, patients can become externally and internally contaminated with one or more radionuclides. Internal contamination can lead to the delivery of harmful ionizing radiation doses to various organs and tissues or the whole body. The clinical consequences can range from acute radiation syndrome (ARS) to the long term development of cancer. Estimating the amount of radioactive material absorbed into the body can guide the management of patients. Treatment includes, in addition to supportive care and long term monitoring, certain medical countermeasures like Prussian blue, Calcium DTPA and Zinc DTPA.

  17. Bioremediation of uranium contaminated Fernald soils

    SciTech Connect

    Delwiche, M.E.; Wey, J.E.; Torma, A.E.

    1994-12-31

    This study investigated the use of microbial bioleaching for removal of uranium from contaminated soils. The ability of bacteria to assist in oxidation and solubilization of uranium was compared to the ability of fungi to produce complexing compounds which have the same effect. Biosorption of uranium by fungi was also measured. Soil samples were examined for changes in mineralogical properties due to these processes. On the basis of these laboratory scale studies a generalized flow sheet is proposed for bioremediation of contaminated Fernald soils.

  18. Soil contamination with radionuclides and potential remediation.

    PubMed

    Zhu, Y G; Shaw, G

    2000-07-01

    Soils contaminated with radionuclides, particularly 137Cs and 90Sr, pose a long-term radiation hazard to human health through exposure via the foodchain and other pathways. Remediation of radionuclide-contaminated soils has become increasingly important. Removal of the contaminated surface soil (often up to 40 cm) or immobilization of radionuclides in soils by applying mineral and chemical amendments are physically difficult and not likely cost-effective in practicality. Reducing plant uptake of radionuclides, especially 137CS and 90Sr by competitive cations contained in chemical fertilizers has the general advantage in large scale, low-level contamination incidents on arable land, and has been widely practiced in central and Western Europe after the Chernobyl accident. Phytoextraction of radionuclides by specific plant species from contaminated sites has rapidly stimulated interest among industrialists as well as academics, and is considered to be a promising bio-remediation method. This paper examines the existing remediation approaches and discusses phytoextraction of radionuclides from contaminated soils in detail. PMID:10819188

  19. MEMBRANE TECHNOLOGIES FOR REMEDIATING CONTAMINATED SOILS: A CRITICAL REVIEW

    EPA Science Inventory

    Regulatory compliance requires the cleanup of soils contaminated with toxic organic and metallic compounds. Several chemical and thermal detoxification technologies have been tested on soils excavated from contaminated sites. Soil washing with aqueous solutions transfers the cont...

  20. Management and disposal of waste from sites contaminated by radioactivity

    NASA Astrophysics Data System (ADS)

    Roberts, Carlyle J.

    1998-06-01

    Various methods of managing and disposing of wastes generated by decontamination and decommissioning (D & D) activities are described. This review of current waste management practices includes a description of waste minimization and volume reduction techniques and their applicability to various categories of radwaste. The importance of the physical properties of the radiation and radioactivity in determining the methodology of choice throughout the D & D process is stressed. The subject is introduced by a survey of the common types of radioactive contamination that must be managed and the more important hazards associated with each type. Comparisons are made among high level, transuranic, low level, and radioactive mixed waste, and technologically-enhanced, naturally-occurring radioactive material (TENORM). The development of appropriate clean-up criteria for each category of contaminated waste is described with the aid of examples drawn from actual practice. This includes a discussion of the application of pathway analysis to the derivation of residual radioactive material guidelines. The choice between interim storage and permanent disposal of radioactive wastes is addressed. Approaches to permanent disposal of each category of radioactive waste are described and illustrated with examples of facilities that have been constructed or are planned for implementation in the near future. Actual experience at older, existing, low-level waste disposal facilities is discussed briefly.

  1. Electrokinetic characterization techniques for contaminated soils

    SciTech Connect

    Eykholt, G.R.; Hung, H.

    1995-12-31

    One important element to the success of electrokinetic remediation of contaminated soils may be the assessment and control of the soil surface chemistry. This is usually reflected by an operative zeta-potential or electroosmotic coefficient, k{sub eo}, found by an electroosmosis test on a plug of contaminated soil. However, several researchers have shown that both the magnitude and uniformity of k{sub eo} change over the course of testing, as does the electric field intensity and zeta-potential, two basic parameters of the fundamental driving force. The electric field intensity can be measured during the test, but it is more difficult to assess the zeta potential. Independent techniques are needed. A conventional technique is dilute electrophoresis, but this test may not be truly representative or convenient. In this research summary, alternative techniques based on electroacoustic phenomena are presented in conjunction with other electrokinetic tests on reference and contaminated soils.

  2. Soil washing of fluorine contaminated soil using various washing solutions.

    PubMed

    Moon, Deok Hyun; Jo, Raehyun; Koutsospyros, Agamemnon; Cheong, Kyung Hoon; Park, Jeong-Hun

    2015-03-01

    Bench-scale soil washing experiments were conducted to remove fluoride from contaminated soils. Five washing solutions including hydrochloric acid (HCl), nitric acid (HNO3), sodium hydroxide (NaOH), sulfuric acid (H2SO4) and tartaric acid (C4H6O6) were tested. The concentration of the washing solutions used ranged from 0.1 to 3 M with a liquid to solid ratio of 10. The soil washing results showed that the most effective washing solution for the removal of fluoride from contaminated soils was HCl. The highest fluoride removal results of approximately 97 % from the contaminated soil were obtained using 3 M HCl. The fluoride removal efficiency of the washing solution increases in the following order: C4H6O6 < NaOH < H2SO4 < HNO3 < HCl. PMID:25552323

  3. Radioactive contamination at federally owned facilities. Final report

    SciTech Connect

    Bernhardt, D.E.; Macbeth, P.J.; Sutherland, A.A.; Grant, M.W.; Sandquist, G.M.

    1982-06-01

    Federally-controlled facilities that are contaminated with radioactivity are listed and described. Estimates of current levels of contamination are provided and decontamination and decommissioning (DandD) procedures are discussed. All of this information has been gathered from available literature and personal contacts with individuals; no new measurements or site visits were made. Finally, estimates of amounts and activities of low-level and transuranic wastes that can be generated from DandD of federally controlled facilities are provided.

  4. [On the problem of biodiagnostics under conditions of radioactive contamination].

    PubMed

    Tsvetnova, O B; Shcheglov, A I; Stolbova, V V

    2014-01-01

    The possibilities of biodiagnostics methods (bioindication and bioassay) have been analyzed for conditions of radioactive contamination of natural ecosystems components. The prospects of using biodiagnostics data to address some practical radioecology problems are discussed. The data on dynamics of long-term indicators in the ecosystems contaminated after the Chernobyl accident are shown. The authors have formulated a number of provisions relating to the accumulative bioindication for structural components of forest ecosystems (arboreal and herbaceous vegetation, mosses, lichens, higher fungi). PMID:25775831

  5. CONTAMINATED SOIL VOLUME ESTIMATE TRACKING METHODOLOGY

    SciTech Connect

    Durham, L.A.; Johnson, R.L.; Rieman, C.; Kenna, T.; Pilon, R.

    2003-02-27

    The U.S. Army Corps of Engineers (USACE) is conducting a cleanup of radiologically contaminated properties under the Formerly Utilized Sites Remedial Action Program (FUSRAP). The largest cost element for most of the FUSRAP sites is the transportation and disposal of contaminated soil. Project managers and engineers need an estimate of the volume of contaminated soil to determine project costs and schedule. Once excavation activities begin and additional remedial action data are collected, the actual quantity of contaminated soil often deviates from the original estimate, resulting in cost and schedule impacts to the project. The project costs and schedule need to be frequently updated by tracking the actual quantities of excavated soil and contaminated soil remaining during the life of a remedial action project. A soil volume estimate tracking methodology was developed to provide a mechanism for project managers and engineers to create better project controls of costs and schedule. For the FUSRAP Linde site, an estimate of the initial volume of in situ soil above the specified cleanup guidelines was calculated on the basis of discrete soil sample data and other relevant data using indicator geostatistical techniques combined with Bayesian analysis. During the remedial action, updated volume estimates of remaining in situ soils requiring excavation were calculated on a periodic basis. In addition to taking into account the volume of soil that had been excavated, the updated volume estimates incorporated both new gamma walkover surveys and discrete sample data collected as part of the remedial action. A civil survey company provided periodic estimates of actual in situ excavated soil volumes. By using the results from the civil survey of actual in situ volumes excavated and the updated estimate of the remaining volume of contaminated soil requiring excavation, the USACE Buffalo District was able to forecast and update project costs and schedule. The soil volume

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

    PubMed Central

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

    2013-01-01

    Measurement of radioactive dose rates in fine sediment that has recently deposited on channel bed-sand provides a solution to address the lack of continuous river monitoring in Fukushima Prefecture after Fukushima Dai-ichi nuclear power plant (FDNPP) accident. We show that coastal rivers of Eastern Fukushima Prefecture were rapidly supplied with sediment contaminated by radionuclides originating from inland mountain ranges, and that this contaminated material was partly exported by typhoons to the coastal plains as soon as by November 2011. This export was amplified during snowmelt and typhoons in 2012. In 2013, contamination levels measured in sediment found in the upper parts of the catchments were almost systematically lower than the ones measured in nearby soils, whereas their contamination was higher in the coastal plains. We thereby suggest that storage of contaminated sediment in reservoirs and in coastal sections of the river channels now represents the most crucial issue. PMID:24165695

  7. In situ vitrification: Test results for a contaminated soil-melting process

    SciTech Connect

    Buelt, J.L.; Timmerman, C.L.; Westsik, J.H. Jr.

    1989-10-01

    In situ vitrification (ISV) is being developed at Pacific Northwest Laboratory for the Department of Energy to stabilize soils and sludges that are contaminated with radioactive and hazardous chemical wastes. ISV is a process that immobilizes contaminated soil in place by converting it to a durable glass and crystalline product similar to obsidian and basalt. In June 1987, a large-scale test of the process was completed at a transuranic-contaminated soil site. The test constituted the first full-scale demonstration of ISV at an actual site. This paper summarizes the results of that test and describes the potential adaptation of the process to radioactive and hazardous chemical waste-contaminated soils. 15 refs., 9 figs., 3 tabs.

  8. In Situ Vitrification: Recent test results for a contaminated soil melting process

    SciTech Connect

    Buelt, J.L.; Timmerman, C.L.; Westsik, J.H. Jr.

    1988-06-01

    In Situ Vitrification (ISV) is being developed at Pacific Northwest Laboratory for the Department of Energy and other clients for the stabilization of soils and sludges contaminated with radioactive and hazardous chemical wastes. ISV is a process that immobilizes contaminated soil in place by converting it to a durable glass and crystalline product that is similar to obsidian. In June 1987, a large-scale test of the process was completed at a transuranic- contaminated soil site. This constituted the first full-scale demonstration of the ISV process at an actual site. This paper summarizes the preliminary results of this test and describes the processes' potential adaptation to radioactive and hazardous chemical waste contaminated soils. 10 refs., 10 figs.

  9. Some aspects of remediation of contaminated soils

    NASA Astrophysics Data System (ADS)

    Bech, Jaume; Korobova, Elena; Abreu, Manuela; Bini, Claudio; Chon, Hyo-Taek; Pérez-Sirvent, Carmen; Roca, Núria

    2014-05-01

    Soils are essential components of the environment, a limited precious and fragile resource, the quality of which should be preserved. The concentration, chemical form and distribution of potential harmful elements in soils depends on parent rocks, weathering, soil type and soil use. However, their concentration can be altered by mismanagement of industrial and mining activities, energy generation, traffic increase, overuse of agrochemicals, sewage sludge and waste disposal, causing contamination, environmental problems and health concerns. Heavy metals, some metalloids and radionuclides are persistent in the environment. This persistence hampers the cost/efficiency of remediation technologies. The choice of the most appropriate soil remediation techniques depends of many factors and essentially of the specific site. This contribution aims to offer an overview of the main remediation methods in contaminated soils. There are two main groups of technologies: the first group dealing with containment and confinement, minimizing their toxicity, mobility and bioavailability. Containment measures include covering, sealing, encapsulation and immobilization and stabilization. The second group, remediation with decontamination, is based on the remotion, clean up and/or destruction of contaminants. This group includes mechanical procedures, physical separations, chemical technologies such as soil washing with leaching or precipitation of harmful elements, soil flushing, thermal treatments and electrokinetic technologies. There are also two approaches of biological nature: bioremediation and phytoremediation. Case studies from Chile, Ecuador, Italy, Korea, Peru, Portugal, Russia and Spain, will be discussed in accordance with the time available.

  10. Phytoremediation of soils contaminated by cadmium

    NASA Astrophysics Data System (ADS)

    Watai, H.; Miyazaki, T.; Fujikawa, T.; Mizoguchi, M.

    2004-12-01

    Phytoremediation is a technique to clean up soils contaminated with heavy metals. Advantages of this method are that (1) This technique is suitable to cleanup soils slightly contaminated with heavy metals in relatively wide area. (2) The expense for clean up is lower than civil engineering techniques. (3) This method can remove heavy metals fundamentally from contaminated. (4) The heavy metals are able to recycle by ashing of plants. Many researches have been done on the phytoremediation up to now, but almost all these researches were devoted to clarify the phytoremediation from the view point of plants themselves. However, few efforts have been devoted to analyze the migrations of heavy metals in soils during the phytoremediation process. The objective of this study is to clarify the features of Cd migration when plant roots are absorbing Cd from the ambient soils. Especially, we focused on finding the Cd migration pattern by changing the soil condition such as plant growing periods, planting densities, and the initial Cd concentration in soils. We planted sunflowers in columns filled with Cd contaminated soils because sunflower is a well-known hyperaccumulator of Cd from soils. By cutting the shoots of plants at the soil surface, and by keeping the plant roots in the soils without disturbance, the Cd concentrations, moisture contents, pH distributions, EC distributions, and dry weight of residual roots in the soils were carefully analyzed. The experimental results showed that (1)The growth of the planted sunflowers were suffered by applying of Cd. (2)The decrease of suction was affected by water uptake by roots at the depth from 0 to 5 cm. Water contents with plants in soils decrease more than without plants. (3)Cd adsorption by roots was predominant within 5cm from soil surface. In addition, it was also shown that there was an optimal Cd concentration where Cd is most effectively adsorbed by the plant. In this experiment we found that 40 to 60 mg kg-1 was the

  11. Simplified method for detecting tritium contamination in plants and soil.

    PubMed

    Andraski, B J; Sandstrom, M W; Michel, R L; Radyk, J C; Stonestrom, D A; Johnson, M J; Mayers, C J

    2003-01-01

    Cost-effective methods are needed to identify the presence and distribution of tritium near radioactive waste disposal and other contaminated sites. The objectives of this study were to (i) develop a simplified sample preparation method for determining tritium contamination in plants and (ii) determine if plant data could be used as an indicator of soil contamination. The method entailed collection and solar distillation of plant water from foliage, followed by filtration and adsorption of scintillation-interfering constituents on a graphite-based solid phase extraction (SPE) column. The method was evaluated using samples of creosote bush [Larrea tridentata (Sessé & Moc. ex DC.) Coville], an evergreen shrub, near a radioactive disposal area in the Mojave Desert. Laboratory tests showed that a 2-g SPE column was necessary and sufficient for accurate determination of known tritium concentrations in plant water. Comparisons of tritium concentrations in plant water determined with the solar distillation-SPE method and the standard (and more laborious) toluene-extraction method showed no significant difference between methods. Tritium concentrations in plant water and in water vapor of root-zone soil also showed no significant difference between methods. Thus, the solar distillation-SPE method provides a simple and cost-effective way to identify plant and soil contamination. The method is of sufficient accuracy to facilitate collection of plume-scale data and optimize placement of more sophisticated (and costly) monitoring equipment at contaminated sites. Although work to date has focused on one desert plant, the approach may be transferable to other species and environments after site-specific experiments. PMID:12809299

  12. Simplified method for detecting tritium contamination in plants and soil

    USGS Publications Warehouse

    Andraski, B.J.; Sandstrom, M.W.; Michel, R.L.; Radyk, J.C.; Stonestrom, D.A.; Johnson, M.J.; Mayers, C.J.

    2003-01-01

    Cost-effective methods are needed to identify the presence and distribution of tritium near radioactive waste disposal and other contaminated sites. The objectives of this study were to (i) develop a simplified sample preparation method for determining tritium contamination in plants and (ii) determine if plant data could be used as an indicator of soil contamination. The method entailed collection and solar distillation of plant water from foliage, followed by filtration and adsorption of scintillation-interfering constituents on a graphitebased solid phase extraction (SPE) column. The method was evaluated using samples of creosote bush [Larrea tridentata (Sesse?? & Moc. ex DC.) Coville], an evergreen shrub, near a radioactive disposal area in the Mojave Desert. Laboratory tests showed that a 2-g SPE column was necessary and sufficient for accurate determination of known tritium concentrations in plant water. Comparisons of tritium concentrations in plant water determined with the solar distillation-SPE method and the standard (and more laborious) toluene-extraction method showed no significant difference between methods. Tritium concentrations in plant water and in water vapor of root-zone soil also showed no significant difference between methods. Thus, the solar distillation-SPE method provides a simple and cost-effective way to identify plant and soil contamination. The method is of sufficient accuracy to facilitate collection of plume-scale data and optimize placement of more sophisticated (and costly) monitoring equipment at contaminated sites. Although work to date has focused on one desert plant, the approach may be transferable to other species and environments after site-specific experiments.

  13. Radioactivity in Virgin Soils and Soils from Some Areas with Closed Uranium Mining Facilities in Bulgaria

    NASA Astrophysics Data System (ADS)

    Yordanova, I.; Staneva, D.; Misheva, L.; Bineva, Ts.; Banov, M.

    2012-04-01

    The soil radioecology is an important part of the environmental research in the country. Since the beginning of the 1970's regular monitoring of the content of different radionuclides in Bulgarian soils has been done. Objective of the studies were virgin soils from high mountain areas, hills and plains (the region of Kozloduy NPP and the Danube river valley). Natural and men-made radionuclides were observed. In the 25-year period after the the contamination with radionuclides due to the 1986 Chernobyl NPP accident a rich data base has been collected, recording the radiation status of the soils in Bulgaria. Special attention has been paid to the contamination with the long-lived technogenic radionuclides caesium-137 and strontium-90. This paper presents a summary of the obtained results. Caesium-137 and strontium-90 were the main men-made radionuclides detected in the examined Bulgarian soils few years after the Chernobyl NPP accident. Their content in the soils from high mountain areas (Rodopa and Rila mountains) is several times higher than that in the soils from North Bulgaria and Sofia fields. High non-homogenity in the pollution within small areas (even as small as several square meters) has been observed. Natural radioactivity was also studied. Averaged values for natural radionuclides like uranium-238, thorium-232, and radium-226 in virgin soils from different areas in the country are presented. A comparison of the dynamics of their behavior throughout the years is done. Bulgaria is a country with intensive uranium mining activities in the past years. That is why radiological monitoring of closed uranium mining facilities in different regions of the country are obligatory and of great interest. This work presents results from such investigations made in regions where remediation has been done. The results have been evaluated according to the Bulgarian radionuclide environment contamination legislation. The necessity of permanent environmental monitoring is

  14. Evaluation of soil radioactivity data from the Nevada Test Site

    SciTech Connect

    1995-03-01

    Since 1951, 933 nuclear tests have been conducted at the Nevada Test Site (NTS) and test areas on the adjacent Tonopah Test Range (TTR) and Nellis Air Force Range (NAFR). Until the early 1960s. the majority of tests were atmospheric, involving detonation of nuclear explosive devices on the ground or on a tower, suspended from a balloon or dropped from an airplane. Since the signing of the Limited Test Ban Treaty in 1963, most tests have been conducted underground, although several shallow subsurface tests took place between 1962 and 1968. As a result of the aboveground and near-surface nuclear explosions, as well as ventings of underground tests, destruction of nuclear devices with conventional explosives, and nuclear-rocket engine tests, the surface soil on portions of the NTS has been contaminated with radionuclides. Relatively little consideration was given to the environmental effects of nuclear testing during the first two decades of operations at the NTS. Since the early 1970s, however, increasingly strict environmental regulations have forced greater attention to be given to contamination problems at the site and how to remediate them. One key element in the current environmental restoration program at the NTS is determining the amount and extent of radioactivity in the surface soil. The general distribution of soil radioactivity on the NTS is already well known as a result of several programs carried out in the 1970s and 1980s. However, questions have been raised as to whether the data from those earlier studies are suitable for use in the current environmental assessments and risk analyses. The primary purpose of this preliminary data review is to determine to what extent the historical data collected at the NTS can be used in the characterization/remediation process.

  15. Soil contamination evaluations: Earthworms as indicators of soil quality

    SciTech Connect

    Linder, G.; Wilbom, D.

    1995-12-31

    Earthworms have frequently been evaluated in the field and laboratory as representatives of the soil community that are indicative of their habitat`s quality. Within a landscape or at a contaminated site, soil quality, or soil health, has become increasingly critical to cleanup-related issues that revolve around questions of ``how clean is clean`` and the bioaccumulation of soil contaminants. Through an overview of numerous field and laboratory studies, the role that earthworms have played in evaluating soil contamination will be reviewed with a particular focus on evaluations of the bioaccumulation potential of chemicals in soil. Within ecological contexts, earthworms can provide information regarding immediately observable adverse affects related, for example, to acute toxicity. Additionally, earthworms can provide information directly related to the bioaccumulation potential of a chemical and trophic transfer of environmental chemicals, especially through the food-chain. Within the decision-making process, soil contamination evaluations must consider future land-use, as well as current and future expressions of adverse biological and ecological effects under field conditions, potentially following remediation. Through integrated field and laboratory studies using earthworms, the authors have been able to identify adversely affected soil communities and have been able to provide information for assessing adverse ecological effects potentially caused by contaminants. Field surveys and on-site or in situ biological testing with earthworms, however, can not alone identify causes of effects. As such, standardized biological tests have been routinely completed in the laboratory so linkages between expression of effects and contaminants could be more readily addressed in conjunction with appropriate chemical data from the field.

  16. [Clinico-radiometric studies of the eye in radioactive contamination].

    PubMed

    Mikhaĭlina, T N; Bazhin, A G

    1994-01-01

    The aim of the study was assessment of local and remote effects of radioactive substances on ocular media and development of measures to remove radionuclides from the eye. Radioactive substances getting into the eye in the form of aerosols, dust, or gaseous mixtures are unevenly distributed in it. The highest radioactivity was found on the skin of the eyelids and orbit, particularly so on the eyelashes and eyebrows, the least one on the cornea and in the conjunctival cavity. A follow-up of 8 to 17 years showed that timely removal of radionuclides from ocular surface prevented the development of specific symptoms and trophic changes of ocular media, of radiation cataracts among other things. The suggested method for washing the skin of the eyelids and orbital area from radioactive contaminants did not induce skin irritation, maceration, sense of discomfort, and is recommended for practice. PMID:8073571

  17. Incineration treatment of arsenic-contaminated soil

    SciTech Connect

    Waterland, L.R.; King, C.; Richards, M.K.; Thurnau, R.C.

    1991-01-01

    An incineration test program was conducted at the US Environmental Protection Agency's Incineration Research Facility to evaluate the potential of incineration as a treatment option for contaminated soils at the Baird and McGuire Superfund site in Holbrook, Massachusetts. The purpose of these tests was to evaluate the incinerability of these soils in terms of the fate of arsenic and lead and the destruction of organic contaminants during the incineration process. The test program consisted of a series of bench-scale experiments with a muffle furnace and a series of incineration tests in a pilot-scale rotary kiln incinerator system.

  18. Bioremediation of petroleum-contaminated soil

    SciTech Connect

    Pearce, K.; Snyman, H.G.; Oellermann, R.A.; Gerber, A.

    1995-12-31

    A pilot-scale study was conducted to evaluate the application of land-farming techniques in bioremediating a soil highly contaminated with petroleum products. A commercial biosupplement, and one prepared with indigenous microorganisms from the contaminated soil, were tested. Application of either of the biosupplements, in addition to the control of pH, moisture, and oxygen levels, resulted in a 94% reduction of the initial total petroleum hydrocarbon concentration (TPHC) (32% mass/mass) over a 70-day period. Implementation of these findings at full scale to bioremediate highly weathered petroleum products showed an average reduction of 89% over 5.5 months. Target levels of 1,400 mg/kg soil were reached from an initial average TPHC concentration of 12,200 mg/kg soil.

  19. Chelant soil-washing technology for metal-contaminated soil.

    PubMed

    Voglar, David; Lestan, Domen

    2014-01-01

    We demonstrate here, in a pilot-scale experiment, the feasibility of ethylenediaminetetraacetate (EDTA)based washing technology for soils contaminated with potentially toxic metals. Acid precipitation coupled to initial alkaline toxic metal removal and an electrochemical advanced oxidation process were used for average recovery of 76 +/- 2% of EDTA per batch and total recycle of water in a closed process loop. No waste water was generated; solid wastes were efficiently bitumen-stabilized before disposal. The technology embodiment, using conventional process equipment, such as a mixer for soil extraction, screen for soil/gravel separation, filter chamber presses for soil/liquid and recycled EDTA separation and soil rinsing, continuous centrifuge separator for removal of precipitated metals and electrolytic cells for process water cleansing, removed up to 72%, 25% and 66% of Pb, Zn and Cd from garden soil contaminated with up to 6960, 3797 and 32.6 mg kg(-1) of Pb, Zn and Cd, respectively, in nine 60kg soil batches. Concentrations of Pb and Zn remaining in the remediated soil and bioaccessible from the simulated human intestinal phase soil were reduced by 97% and 96% and were brought under the level of determination for Cd. In the most cost-effective operation mode, the material and energy costs of remediation amounted to 50.5 Euros ton(-1) soil and the total cost to 299 Euros ton(-1). PMID:24701937

  20. Solid phase bioremediation of petroleum contaminated soils

    SciTech Connect

    Potter, C.D.

    1992-11-01

    Solid phase bioremediation of petroleum contaminated soil involves aerobic biodegradation in an above grade treatment bed. This treatment technology is proposed for remediating soils contaminated by petroleum from leaking underground fuel storage tanks at various sites at the Oak Ridge Y-12 Plant. The treatment technology uses bacteria to degrade the petroleum hydrocarbons. The environmentally safe end products of the biodegradation process are carbon dioxide and water. A large, relatively level area is required to construct the perimeter berms, place the liner, and spread the contaminated soil in a 1 to 2 foot thick layer. A porous media is placed on top of the liner for protection and for proper drainage of leachate. Water, nutrients, and microorganisms are introduced into the soil in the treatment bed using conventional agricultural spraying techniques. Oxygen is supplied to the soil by periodic tilling on an ``as needed`` basis. To prevent soil erosion and to minimize leachate production during precipitation events, the treatment bed is completely covered by a plastic film. The treatment process is expected to require 3 to 8 months after construction is completed.

  1. [Radioecological investigation of the soil cover of eastern Urals State radioactive reserve and neighboring areas].

    PubMed

    Mikhaĭlovskaia, L N; Molchanova, I V; Karavaeva, E N; Pozolotina, V N; Tarasov, O V

    2011-01-01

    The contamination levels and spatial distribution of 90Sr and 137Cs in the soil cover of the Eastern Ural State Radioactive Reserve and neighboring areas have been studied. Situated in the Chelyabinsk region, the Reserve embraces the frontal part of the Eastern Urals Radioactive Trace. This Trace emerged in 1957 as a result of the nuclear accident at the Production Association "Mayak". In the studied areas, the content of radionuclides in soils decreases exponentially as the distance from the source of contamination increases. 90Sr received by the soil cover as a result of the accident in 1957 has remained the main contaminant of the Reserve central part (97% of the total contamination). Its contribution throughout western neighboring areas reduces up to 67%, which decreases the effect of 90Sr on the environment. Within eastern neighboring areas, soil is mainly contaminated by 137Cs received as a result of the wind disseminated dried sediments from the shores of Lake Karachay (1967) that was used for dumping high-level radioactive waste. Also observed was enrichment of forest litters with this radionuclide due to current atmospheric fallout. PMID:21950106

  2. Industrial-Scale Processes For Stabilizing Radioactively Contaminated Mercury Wastes

    SciTech Connect

    Broderick, T. E.; Grondin, R.

    2003-02-24

    This paper describes two industrial-scaled processes now being used to treat two problematic mercury waste categories: elemental mercury contaminated with radionuclides and radioactive solid wastes containing greater than 260-ppm mercury. The stabilization processes were developed by ADA Technologies, Inc., an environmental control and process development company in Littleton, Colorado. Perma-Fix Environmental Services has licensed the liquid elemental mercury stabilization process to treat radioactive mercury from Los Alamos National Laboratory and other DOE sites. ADA and Perma-Fix also cooperated to apply the >260-ppm mercury treatment technology to a storm sewer sediment waste collected from the Y-12 complex in Oak Ridge, TN.

  3. Monitoring Potential Transport of Radioactive Contaminants in Shallow Ephemeral Channels

    SciTech Connect

    Miller, Julianne J.; Mizell, Steve A.; Nikolich, George; Campbell, Scott A.

    2012-02-01

    The U.S. Department of Energy (DOE) National Nuclear Security Administration (NNSA), Nevada Site Office (NSO), Environmental Restoration Soils Activity has authorized the Desert Research Institute (DRI) to conduct field assessments of potential sediment transport of contaminated soil from Corrective Action Unit (CAU) 550, Area 8 Smoky Contamination Area (CA), during precipitation runoff events. CAU 550 includes Corrective Action Sites (CASs) 08-23-03, 08-23-04, 08-23-06, and 08-23-07; these CASs are associated with tests designated Ceres, Smoky, Oberon, and Titania, respectively.

  4. Thermal treatment of fuel-contaminated soil

    SciTech Connect

    Not Available

    1988-10-01

    A patent has been issued for the apparatus and method for Low Temperature Thermal Stripping (LT/sup 3/) of volatile organic compounds (VOCs) from soil. LT/sup 3/ is a hazardous waste thermal treatment system and is used to clean up fuel-contaminated soil from leaking underground storage tanks. Representing a significant breakthrough in the treatment of polluted soil, LT/sup 3/ is a unique mix of proven techniques combined in an innovative way to provide an efficient cost-effective treatment method.

  5. Evaluation of soil washing for radiologically contaminated soils

    SciTech Connect

    Gombert, D. II

    1994-03-01

    Soil washing has been applied internationally to decontaminate soils due to the widespread increase in environmental awareness manifested in the United States by promulgation of the Comprehensive Environmental Response, Compensation and Liability Act, yet we continue to lack understanding on why the technique works in one application and not in another. A soil washing process typically integrates a variety of modules, each designed to decontaminate the matrix by destroying a particular phase or segregating a particle size fraction in which the contaminants are concentrated. The more known about how the contaminants are fixed, the more likely the process will succeed. Much can be learned from bioavailability studies on heavy metals in soils. Sequential extraction experiments designed to destroy one fixation mechanism at a time can be used to determine how contaminants are bound. This knowledge provides a technical basis for designing a processing strategy to efficiently decontaminate soil while creating a minimum of secondary wastes. In this study, a soil from the Idaho National Engineering Laboratory was physically and chemically characterized, then sequentially extracted to determine if soil washing could be effectively used to remove cesium, cobalt and chromium.

  6. REMEDIATION OF PCB IN CONTAMINATED SOIL

    EPA Science Inventory

    A pilot-scale study will be conducted to evaluate the bioremedial techniques of natural attenuation, sequenced anaerobic/aerobic treatment, and addition of a commercially available microbial amendment product for use in treating PCB contaminated soils at Air Force Base sites. Th...

  7. REMEDIATION OF RADIUM FROM CONTAMINATED SOIL

    EPA Science Inventory

    The objective of this study was to demonstrate the application of a physico-chemical separation process for the removal of radium from a sample of contaminated soil at the Ottawa, Illinois, site near Chicago. The size/activity distribution analyzed among the particles coarser tha...

  8. INCINERATION TREATMENT OF ARSENIC-CONTAMINATED SOIL

    EPA Science Inventory

    An incineration test program was conducted at the US Environmental Protection Agency's Incineration Research Facility to evaluate the potential of incineration as a treatment option for contaminated soils at the Baird and McGuire Superfund site in Holbrook, Massachusetts. he purp...

  9. REMEDIATING PESTICIDE CONTAMINATED SOILS USING SOLVENT EXTRACTION

    EPA Science Inventory

    Bench-scale solvent extraction studies were performed on soil samples obtained from a Superfund site contaminated with high levels of p,p'-DDT, p,p'-DDD,, p,p'-DDE and toxaphene. The effectiveness of the solvent extraction process was assessed using methanol and 2-propanol as sol...

  10. INCINERATION TREATMENT OF ARSENIC-CONTAMINATED SOIL

    EPA Science Inventory

    An incineration test program was conducted at the U.S. Environmental Protection Agency's Incineration Research Facility to evaluate the potential of incineration as a treatment option for contaminated soils at the Baird and McGuire Superfund site in Holbrook, Massachusetts. The p...

  11. Firm contracts for treatability tests on contaminated soils

    SciTech Connect

    Not Available

    1989-08-01

    Geosafe Corporation, a Pacific Northwest-headquartered hazardous waste remediation company, announced that is has successfully completed treatability testing of contaminated soils under contract with Woodward Clyde Consultants of Denver, Colorado, the prime contractor for a major hazardous waste site in the Western United States. The tests are being conducted at the University of Washington with Geosafe's specially-designed test equipment. The recently concluded testing confirms the ability of Geosafe's patented in situ vitrification (ISV) technology to treat soils containing a variety of organic and inorganic contaminants. ISV, for which Geosafe has worldwide rights, is the only technology available today that will fully comply with the Superfund Amendments and Reauthorization Act. The ability of ISV to treat mixtures of organic, inorganic and radioactive wastes in situ, in a single process, offers distinct advantages over excavation, transportation and incineration. During the ISV process, organic contaminants are pyrolized and the inorganics present are chemically incorporated into the molten soil which, when cooled, resembles naturally-occurring obsidian.

  12. Sites in the United States contaminated with radioactivity.

    PubMed

    Wolbarst, A B; Blom, P F; Chan, D; Cherry, R N; Doehnert, M; Fauver, D; Hull, H B; MacKinney, J A; Mauro, J; Richardson, A C; Zaragoza, L

    1999-09-01

    Over the century that radioactive materials have been mined, processed, produced, and utilized, many sites across the United States have become contaminated. Such sites include bases and installations of the Department of Defense, weapons production and research facilities of the Department of Energy, properties under the authority of other Federal agencies, privately-owned and governmental facilities that are licensed by the Nuclear Regulatory Commission and its Agreement States, and sites licensed by or the responsibility of states. This review reports on aspects of work by the Environmental Protection Agency, the Department of Defense, the Department of Energy, the Nuclear Regulatory Commission, and others to identify sites contaminated with radioactive materials. It also describes the principal programs that have been instituted to deal with them. PMID:10456495

  13. Radioactivity of the soil in Vojvodina (northern province of Serbia and Montenegro).

    PubMed

    Bikit, I; Slivka, J; Conkić, Lj; Krmar, M; Vesković, M; Zikić-Todorović, N; Varga, E; Curcić, S; Mrdja, D

    2005-01-01

    The widespread public belief that during the bombardment of Vojvodina (Yugoslavia) this region was contaminated by depleted uranium has recently raised public concern with respect to the potential contamination of agricultural products due to soil radioactivity. Based on the gamma-spectrometric analysis of 50 soil samples taken from the region of Vojvodina we concluded that there is no increase of radioactivity that could endanger the food production. Taking into account the transfer factors of 137Cs to plants, the measured activity concentrations of this isotope should not endanger the health safety of the produced food. No traces of depleted uranium have been found. The natural radioactivity levels are compared with the results form other countries. PMID:15465176

  14. Radioactive waste and contamination in the former Soviet Union

    SciTech Connect

    Suokko, K.; Reicher, D. )

    1993-04-01

    Decades of disregard for the hazards of radioactive waste have created contamination problems throughout the former Soviet Union rivaled only by the Chernobyl disaster. Although many civilian activities have contributed to radioactive waste problems, the nuclear weapons program has been by far the greatest culprit. For decades, three major weapons production facilities located east of the Ural Mountains operated in complete secrecy and outside of environmental controls. Referred to until recently only by their postal abbreviations, the cities of Chelyabinsk-65, Tomsk-7, and Krasnoyarsk-26 were open only to people who worked in them. The mismanagement of waste at these sites has led to catastrophic accidents and serious releases of radioactive materials. Lack of public disclosure, meanwhile, has often prevented proper medical treatment and caused delays in cleanup and containment. 5 refs.

  15. [Migration of industrial radionuclides in soils and benthal deposits at the coastal margins of the temporary waste storage facility (TWSF) of the Northwest Center for Radioactive Waste Management (SevRAO) and its influence on the possible contamination of the sea offshore waters].

    PubMed

    Filonova, A A; Seregin, V A

    2014-01-01

    For obtaining the integral information about the current radiation situation in the sea offshore waters of the temporary waste storage facility (TWSF) of the Northwest Center for Radioactive Waste Management "SevRAO" in the Andreeva Bay and in the settle Gremikha with a purpose of a comprehensive assessment of its condition there was performed radiation-ecological monitoring of the adjacent sea offshore waters of the TWSF. It was shown that in the territory of industrial sites of the TWSF as a result of industrial activity there are localized areas of pollution by man-made radionuclides. As a result of leaching of radionuclides by tidal stream, snowmelt and rainwater radioactive contamination extends beyond the territory of the sanitary protection zone and to the coastal sea offshore waters. To confirm the coastal pollution of the sea offshore waters the levels of mobility of 90Sr and 137Cs in environmental chains and bond strength of them with the soil and benthal deposits were clarified by determining with the method of detection of the forms of the presence of radionuclides in these media. There was established a high mobility of 137Cs and 90Sr in soils and benthal deposits (desorption coefficient (Kd) of 137Cs and 90Sr (in soils - 0.56 and 0.98), in the sediments - 0.82). The migration of radionuclides in environmental chains can lead to the contamination of the environment, including the sea offshore waters. PMID:25051732

  16. Evidence of the Generation of Isosaccharinic Acids and Their Subsequent Degradation by Local Microbial Consortia within Hyper-Alkaline Contaminated Soils, with Relevance to Intermediate Level Radioactive Waste Disposal

    PubMed Central

    Rout, Simon P.; Charles, Christopher J.; Garratt, Eva J.; Laws, Andrew P.; Gunn, John; Humphreys, Paul N.

    2015-01-01

    The contamination of surface environments with hydroxide rich wastes leads to the formation of high pH (>11.0) soil profiles. One such site is a legacy lime works at Harpur Hill, Derbyshire where soil profile indicated in-situ pH values up to pH 12. Soil and porewater profiles around the site indicated clear evidence of the presence of the α and β stereoisomers of isosaccharinic acid (ISA) resulting from the anoxic, alkaline degradation of cellulosic material. ISAs are of particular interest with regards to the disposal of cellulosic materials contained within the intermediate level waste (ILW) inventory of the United Kingdom, where they may influence radionuclide mobility via complexation events occurring within a geological disposal facility (GDF) concept. The mixing of uncontaminated soils with the alkaline leachate of the site resulted in ISA generation, where the rate of generation in-situ is likely to be dependent upon the prevailing temperature of the soil. Microbial consortia present in the uncontaminated soil were capable of surviving conditions imposed by the alkaline leachate and demonstrated the ability to utilise ISAs as a carbon source. Leachate-contaminated soil was sub-cultured in a cellulose degradation product driven microcosm operating at pH 11, the consortia present were capable of the degradation of ISAs and the generation of methane from the resultant H2/CO2 produced from fermentation processes. Following microbial community analysis, fermentation processes appear to be predominated by Clostridia from the genus Alkaliphilus sp, with methanogenesis being attributed to Methanobacterium and Methanomassiliicoccus sp. The study is the first to identify the generation of ISA within an anthropogenic environment and advocates the notion that microbial activity within an ILW-GDF is likely to influence the impact of ISAs upon radionuclide migration. PMID:25748643

  17. Evidence of the generation of isosaccharinic acids and their subsequent degradation by local microbial consortia within hyper-alkaline contaminated soils, with relevance to intermediate level radioactive waste disposal.

    PubMed

    Rout, Simon P; Charles, Christopher J; Garratt, Eva J; Laws, Andrew P; Gunn, John; Humphreys, Paul N

    2015-01-01

    The contamination of surface environments with hydroxide rich wastes leads to the formation of high pH (>11.0) soil profiles. One such site is a legacy lime works at Harpur Hill, Derbyshire where soil profile indicated in-situ pH values up to pH 12. Soil and porewater profiles around the site indicated clear evidence of the presence of the α and β stereoisomers of isosaccharinic acid (ISA) resulting from the anoxic, alkaline degradation of cellulosic material. ISAs are of particular interest with regards to the disposal of cellulosic materials contained within the intermediate level waste (ILW) inventory of the United Kingdom, where they may influence radionuclide mobility via complexation events occurring within a geological disposal facility (GDF) concept. The mixing of uncontaminated soils with the alkaline leachate of the site resulted in ISA generation, where the rate of generation in-situ is likely to be dependent upon the prevailing temperature of the soil. Microbial consortia present in the uncontaminated soil were capable of surviving conditions imposed by the alkaline leachate and demonstrated the ability to utilise ISAs as a carbon source. Leachate-contaminated soil was sub-cultured in a cellulose degradation product driven microcosm operating at pH 11, the consortia present were capable of the degradation of ISAs and the generation of methane from the resultant H2/CO2 produced from fermentation processes. Following microbial community analysis, fermentation processes appear to be predominated by Clostridia from the genus Alkaliphilus sp, with methanogenesis being attributed to Methanobacterium and Methanomassiliicoccus sp. The study is the first to identify the generation of ISA within an anthropogenic environment and advocates the notion that microbial activity within an ILW-GDF is likely to influence the impact of ISAs upon radionuclide migration. PMID:25748643

  18. Guide to treatment technology for contaminated soils

    SciTech Connect

    Tran, H.; Aylward, R.

    1992-08-04

    This document is a guide for the screening of alternative treatment technologies for contaminated soils. The contents of this guide are organized into: 1. Introduction, II. Utilizing the table, III. Tables: Contamination Versus Technology, TV. Contaminant Waste Groups, and V. References. The four Contaminations Versus Technology tables are designed to identify the effectiveness and/or potential applicability of technologies to some or all compounds within specific waste groups. The tables also present limitations and special use considerations for the particular treatment technology. The phase of development of the technology is also included in the table. The phases are: Available, Innovative, and Emerging technologies. The technologies presented in this guide are organized according to the method of treatment. The four (4) treatment methods are Biological, Solidification/Stabilization, Thermal, and Chemical/Physical Treatment. There are several processing methods; some are well developed and proven, and others are in the development stage.

  19. Ecological risk assessment of contaminated soil.

    PubMed

    Jensen, John; Pedersen, Marianne Bruus

    2006-01-01

    This review has described three cases of ecological risk assessment. The cases include two heavy metals (Cu and Zn) and an anthropogenic organic chemical (DDT). It concludes that there are at least two major constraints hampering the use of laboratory tests to predict effects under natural field conditions. One key issue is bioavailability, and another is suboptimal conditions or multiple stresses in the field such as climatic stress (drought, frost), predators, competition, or food shortage. On the basis of the presented case studies, it was possible to answer three essential questions often raised in connection to ecological risk assessment of contaminated sites. 1. To what extend does soil screening level (SSL) estimate the risk? The SSL are generally derived at levels corresponding to the lowest observed effect levels in laboratory studies, which often is close to the background levels found in many soils. In the cases of zinc and especially DDT, the SSL seemed quite conservative, whereas for copper they resemble the level at which changes in the community structure of soil microarthropods and the plant community have been observed at contaminated sites. The SSL correspond as a whole relatively well with concentrations where no effects or only minor effects were observed in controlled field studies. However, large variation in field surveys can often make it difficult to conclude to what extent the SSL corresponded to no-effect levels in the field. 2. Do bioassays represent a more realistic risk estimate? Here, there is no firm conclusion. The zinc study in UK showed a better relationship between the outcome of ex situ bioassays and field observations than the SSL. The latter overestimated the risk compared to field observations. However, this would be species dependent, as the sensitivity to metals may vary considerably between recognized test species, even within the same group of organisms, such as Folsomia candida and Folsomia fimetaria or Eisenia fetida

  20. Auxiliary analyses in support of performance assessment of a hypothetical low-level waste facility: Two-phase flow and contaminant transport in unsaturated soils with application to low-level radioactive waste disposal. Volume 2

    SciTech Connect

    Binning, P.; Celia, M.A.; Johnson, J.C.

    1995-05-01

    A numerical model of multiphase air-water flow and contaminant transport in the unsaturated zone is presented. The multiphase flow equations are solved using the two-pressure, mixed form of the equations with a modified Picard linearization of the equations and a finite element spatial approximation. A volatile contaminant is assumed to be transported in either phase, or in both phases simultaneously. The contaminant partitions between phases with an equilibrium distribution given by Henry`s Law or via kinetic mass transfer. The transport equations are solved using a Galerkin finite element method with reduced integration to lump the resultant matrices. The numerical model is applied to published experimental studies to examine the behavior of the air phase and associated contaminant movement under water infiltration. The model is also used to evaluate a hypothetical design for a low-level radioactive waste disposal facility. The model has been developed in both one and two dimensions; documentation and computer codes are available for the one-dimensional flow and transport model.

  1. Monitoring Potential Transport of Radioactive Contaminants in Shallow Ephemeral Channels: FY 2012

    SciTech Connect

    Miller, Julianne J.; Mizell, Steve A.; McCurdy, Greg; Campbell, Scott A.

    2012-09-01

    The US Department of Energy (DOE) National Nuclear Security Administration (NNSA), Nevada Site Office (NSO), Environmental Management’s Soils Activity has authorized the Desert Research Institute (DRI) to conduct field assessments of potential sediment transport of contaminated soil from Corrective Action Unit (CAU) 550, Smoky Contamination Area (CA), during precipitation runoff events. CAU 550 includes Corrective Action Sites (CASs) 08-23-03, 08-23-04, 08-23-06, and 08-23-07; these CASs are associated with tests designated Ceres, Smoky, Oberon, and Titania, respectively. Field measurements at the T-4 Atmospheric Test Site, CAU 370, suggest that radioactive material may have migrated along a shallow ephemeral drainage that traverses the site (NNSA/NSO, 2009). (It is not entirely clear how contaminated soils got into their present location at the T-4 Site, but flow to the channel has been redirected and the contamination does not appear to be migrating at present.) Although DRI initially looked at the CAU 370 site, given that it could not be confirmed that migration of contamination into the channel was natural, an alternate study site was selected at CAU 550. Aerial surveys in selected portions of the Nevada National Security Site (NNSS) also suggest that radioactivity may be migrating along ephemeral channels in Areas 3, 8, 11, 18, and 25 (Colton, 1999). Figure 1 shows the results of a low-elevation aerial survey (Colton, 1999) in Area 8. The numbered markers in Figure 1 identify ground zero for three safety experiments conducted in 1958 [Oberon (number 1), Ceres (number 2), and Titania (number 4)] and a weapons effects test conducted in 1964, Mudpack (number 3). This survey suggests contaminants may be migrating down the ephemeral channels that traverse CAU 550. Note particularly the lobe of higher concentration extending southeastward at the south end of the high concentration area marked as number 3 in Figure 1. CAU 550 in Area 8 of the NNSS was selected for

  2. TNT transport and fate in contaminated soil

    SciTech Connect

    Comfort, S.D.; Shea, P.J.; Hundal, L.S.

    1995-11-01

    Past disposal practices at munitions production plants have contaminated terrestrial and aquatk ecosystems with 2,4,6-trinitrotoluene (TNT). We determined TNT transport, degradation, and long-term sorption characteristics in soil. Transport experiments were conducted with repacked, unsaturated soil columns containing uncontaminated soil or layers of contaminated and uncontaminated soil. Uncontaminated soil columns received multiple pore volumes (22-50) of a TNT-{sup 3}H{sub 2}O pulse, containing 70 or 6.3 mg TNT L{sup -1} at a constant pore water velocity. TNT breakthrough curves (BTCs) never reached initial solute pulse concentrations. Apex concentrations (C/C{sub o}) were between 0.6 and 0.8 for an initial pulse of 70 mg TNT L{sup -1} and 0.2 to 0.3 for the 6.3 mg TNT L{sup -1} pulse. Earlier TNT breakthrough was observed at the higher pulse concentration. This mobility difference was predicted from the nonlinear adsorption isotherm determined for TNT sorption. In all experiments, a significant fraction of added TNT was recovered as amino degradates of TNT. Mass balance estimates indicated 81% of the added TNT was recovered (as TNT and amino degradates) from columns receiving the 70 mg TNT L{sup -1} pulse compared to 35% from columns receiving the 6.3 mg TNT L{sup -1} pulse. Most of the unaccountable TNT was hypothesized to be unextractable. This was supported by a 168-d sorption experiment, which found that within 14d, 80% of {sup 14}C activity (added as {sup 14}C-TNT) was adsorbed and roughly 40% unextractable. Our observations illustrate that TNT sorption and degradation are concentration-dependent and the assumptions of linear adsorption and adsorption-desorption singularity commonly used in transport modeling, may not be valid for predicting TNT transport in munitions-contaminated soils. 29 refs., 6 figs., 7 tabs.

  3. Method for treatment of soils contaminated with organic pollutants

    DOEpatents

    Wickramanayake, Godage B.

    1993-01-01

    A method for treating soil contaminated by organic compounds wherein an ozone containing gas is treated with acid to increase the stability of the ozone in the soil environment and the treated ozone applied to the contaminated soil to decompose the organic compounds. The soil may be treated in situ or may be removed for treatment and refilled.

  4. Trench ‘Bathtubbing’ and Surface Plutonium Contamination at a Legacy Radioactive Waste Site

    PubMed Central

    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+240Pu in 0.45 μm-filtered water), and there is an associated contamination of Pu in surface soils. The highest 239+240Pu 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. PMID:24256473

  5. Bioremediation of uranium contaminated soils and wastes

    SciTech Connect

    Francis, A.J.

    1998-12-31

    Contamination of soils, water, and sediments by radionuclides and toxic metals from uranium mill tailings, nuclear fuel manufacturing and nuclear weapons production is a major concern. Studies of the mechanisms of biotransformation of uranium and toxic metals under various microbial process conditions has resulted in the development of two treatment processes: (1) stabilization of uranium and toxic metals with reduction in waste volume and (2) removal and recovery of uranium and toxic metals from wastes and contaminated soils. Stabilization of uranium and toxic metals in wastes is accomplished by exploiting the unique metabolic capabilities of the anaerobic bacterium, Clostridium sp. The radionuclides and toxic metals are solubilized by the bacteria directly by enzymatic reductive dissolution, or indirectly due to the production of organic acid metabolites. The radionuclides and toxic metals released into solution are immobilized by enzymatic reductive precipitation, biosorption and redistribution with stable mineral phases in the waste. Non-hazardous bulk components of the waste volume. In the second process uranium and toxic metals are removed from wastes or contaminated soils by extracting with the complexing agent citric acid. The citric-acid extract is subjected to biodegradation to recover the toxic metals, followed by photochemical degradation of the uranium citrate complex which is recalcitrant to biodegradation. The toxic metals and uranium are recovered in separate fractions for recycling or for disposal. The use of combined chemical and microbiological treatment process is more efficient than present methods and should result in considerable savings in clean-up and disposal costs.

  6. Remediating pesticide contaminated soils using solvent extraction

    SciTech Connect

    Sahle-Demessie, E.; Meckes, M.C.; Richardson, T.L.

    1996-12-31

    Bench-scale solvent extraction studies were performed on soil samples obtained from a Superfund site contaminated with high levels of p,p{prime}-DDT, p,p{prime}-DDE and toxaphene. The effectiveness of the solvent extraction process was assessed using methanol and 2-propanol as solvents over a wide range of operating conditions. It was demonstrated that a six-stage methanol extraction using a solvent-to-soil ratio of 1.6 can decrease pesticide levels in the soil by more than 99% and reduce the volume of material requiring further treatment by 25 times or more. The high solubility of the pesticides in methanol resulted in rapid extraction rates, with the system reaching quasi-equilibrium state in 30 minutes. The extraction efficiency was influenced by the number of extraction stages, the solvent-to-soil ratio, and the soil moisture content. Various methods were investigated to regenerate and recycle the solvent. Evaporation and solvent stripping are low cost and reliable methods for removing high pesticide concentrations from the solvent. For low concentrations, GAC adsorption may be used. Precipitating and filtering pesticides by adding water to the methanol/pesticide solution was not successful when tested with soil extracts. 26 refs., 10 figs., 6 tabs.

  7. Radioactive contamination at nuclear fuel cycle facilities. Final report

    SciTech Connect

    Bernhardt, D.E.; Grant, M.W.; Rich, D.C.; Jensen, C.M.; Macbeth, P.J.

    1982-01-01

    This report presents information to characterize uranium fuel cycle facilities (excluding reactors), levels of contamination at those facilities, and volumes and activity of wastes associated with their decontamination and decommissioning (DandD). It is one of a series of reports providing information to assist the U.S. Environmental Protection Agency in setting standards and guidelines for permissible residual levels of radioactivity from DandD. The categories of facilities covered by this report are: Uranium mines, Uranium mills, Uranium hexafluoride conversion plants, Fuel fabrication plants, including both low and high enriched uranium and mixed oxide facilities. Both active and inactive facilities are identified. The highest volumes of DandD waste (hundreds of millions of cubic meters) are associated with uranium mines, while the highest amounts of radioactivity are a result of DandD at fuel reprocessing plants.

  8. Biological degradation of TNT-contaminated soil

    SciTech Connect

    Manning, J.F.; Boopathy, R.

    1995-12-31

    The concept of using biological slurry reactors to remediate soil contaminated with TNT has been investigated at the laboratory scale. Important parameters include an organic co-substrate and appropriate amounts of nitrogen and phosphorus added as nutrients. Normally, the degradation requires an organic co-substrate. The type of co-substrate can have a significant impact on the rate and extent of degradation. Succinate, malate, molasses, and glucose are all acceptable co-substrates. Molasses, or succinate with added yeast extract and/or peptone, provides superior rates of removal. Consortia of microorganisms isolated from various sites can also degrade TNT. To exploit the microbial system, laboratory scale soil slurry reactors have been operated, achieving reductions in TNT concentrations on the order of 90-99% from initial TNT concentrations of 7,000-10,000 mg/kg. Laboratory scale tests have shown that all of the intermediates can be removed by microbial degradation. Laboratory reactors operated with 15% volume replacement one, two, or three times a week achieved removal of 95-99% of the TNT in the feed soil. This system can reduce TNT concentrations to less than 20 mg/kg in treated soil. In particular, operation of the reactors in an aerobic-anoxic sequenced pattern promotes the conversion of TNT to CO{sub 2} and microbial biomass. Radiolabeling studies demonstrated that 50% of the TNT is mineralized, with 30% of the original labeled TNT being converted to microbial biomass. To take advantage of this technology, a field demonstration in which the soil slurry reactor is being used to degrade explosives-contaminated soil is currently being conducted.

  9. Soil Washing Experiment for Decontamination of Contaminated NPP Soil

    SciTech Connect

    Son, J.K.; Kang, K.D.; Kim, K.D.; Ha, J.H.; Song, M.J.

    2006-07-01

    The preliminary experiment was performed to obtain the operating conditions of soil washing decontamination process such as decontamination agent, decontamination temperature, decontamination time and ratio of soil and decontamination agent. To estimate decontamination efficiency, particle size of soil was classified into three categories; {>=} 2.0 mm, 2.0 {approx} 0.21 mm and {<=} 0.21 mm. Major target of this experiment was decontamination of Cs-137. The difference of decontamination efficiency using water and neutral salts as decontamination agent is not high. It is concluded that the best temperature of decontamination agent is normal temperature and the best decontamination time was about 60 minutes. And the best ratio of soil and decontamination agent is 1:10. In case of Cs decontamination for fine soils, the decontamination results using neutral salts such as Na{sub 2}CO{sub 3} and Na{sub 3}PO{sub 4} shows some limits while using strong acid such as sulfuric acid or hydrochloric acid shows high decontamination efficiency ({>=}90%). But we conclude that decontamination using strong acid is also inappropriate because of the insufficiency of decontamination efficiency for highly radioactive fine soils and the difficulty for treatment of secondary liquid waste. It is estimated that the best decontamination process is to use water as decontamination agent for particles which can be decontaminated to clearance level, after particle size separation. (authors)

  10. Natural and man-made radioactivity: Chernobyl soils.

    NASA Astrophysics Data System (ADS)

    Gillmore, Gavin; Flowers, Alan

    2014-05-01

    In 1986 a reactor at the Chernobyl Nuclear Plant suffered a large explosion. The result had wide-ranging impacts. 31 severely exposed emergency workers died from acute radiation syndrome and 19 more later died from different causes. The perhaps controversial prediction by some authors is that around 4,000 will eventually die as a result of the increased cancer risk. A 19-mile restriction zone exists around the former reactor, but during the past 25 years radiation levels have fallen and it is now possible to take part in conducted tours of the deserted city of Pripyat, and the Chernobyl reactor site. Soil levels, however, remain highly radioactive, particularly in the restricted area. Kingston University holds:- • Soil profile sets from 3 locations in Belarus, with repeats at same location 1996 and 2000. • Lake sediment core samples. • Soil profiles at forestry sites. • Surface samples in a region suspected to have actinide content at 200km from Chernobyl. In addition to the above the impact of naturally occurring radon on human health around Chernobyl should not be ignored. About 23 per cent of homes in Ukraine are estimated to have radon levels above 100 Bq m-3, whilst concentrations of 10,000 Bq m-3 or more are known to exist in public water supplies. Some researchers have also suggested that mean annual doses of irradiation of the population caused by radon and it's progeny in air in buildings exceeds the doses received now by inhabitants of settlements located in the territories polluted by Chernobyl-derived nuclides in the Mogilev and Gomel regions in Belarus. This project incorporates a temporal comparison of transport results in undisturbed soils variously over a number of years, demonstrating relative measurements using both the original and new samples. This project will also focus on lake sediments from Southern Belarus and is a 'work in progress'. However, what we can say at this stage is that it is notable that the long lived isotopes of Cs-137

  11. 48 CFR 945.603-71 - Disposal of radioactively contaminated personal property.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Contractor Inventory 945.603-71 Disposal of radioactively contaminated personal property. Special procedures regarding the disposal of radioactively contaminated property may be found at 41 CFR 109-45.50. ... contaminated personal property. 945.603-71 Section 945.603-71 Federal Acquisition Regulations System...

  12. Aromatic plant production on metal contaminated soils.

    PubMed

    Zheljazkov, Valtcho D; Craker, Lyle E; Xing, Baoshan; Nielsen, Niels E; Wilcox, Andrew

    2008-06-01

    Field and container experiments were conducted to assess the feasibility of growing aromatic crops in metal contaminated areas and the effect of metals on herbage and oil productivity. The field experiments were conducted in the vicinities of the Non-Ferrous Metals Combine (Zn-Cu smelter) near Plovdiv, Bulgaria using coriander, sage, dill, basil, hyssop, lemon balm, and chamomile grown at various distances from the smelter. Herbage essential oil yields of basil, chamomile, dill, and sage were reduced when they were grown closer to the smelter. Metal removal from the site with the harvestable plant parts was as high as 180 g ha(-1) for Cd, 660 g ha(-1) for Pb, 180 g ha(-1) for Cu, 350 g ha(-1) for Mn, and 205 g ha(-1) for Zn. Sequential extraction of soil demonstrated that metal fractionation was affected by the distance to the smelter. With decreasing distance to the smelter, the transfer factor (TF) for Cu and Zn decreased but increased for Cd, while the bioavailability factor (BF) for Cd, Pb, Cu, Mn, and Zn decreased. Scanning electron microscopy and X-ray microanalyses of contaminated soil verified that most of the Pb, Cd, Mn, Cu, and Zn were in the form of small (<1 microm) particles, although there were larger particles (1-5 microm) with high concentrations of individual metals. This study demonstrated that high concentrations of heavy metals in soil or growth medium did not result in metal transfer into the essential oil. Of the tested metals, only Cu at high concentrations may reduce oil content. Our results demonstrated that aromatic crops may not have significant phytoremediation potential, but growth of these crops in metal contaminated agricultural soils is a feasible alternative. Aromatic crops can provide economic return and metal-free final product, the essential oil. PMID:18353428

  13. Enhanced bioremediation of PAH contaminated soils from coal processing sites

    SciTech Connect

    Joshi, M.M.; Lee, S.

    1995-12-31

    The polycyclic aromatic hydrocarbons (PAH) are a potential hazard to health due to their carcinogenic, mutagenic nature and acute toxicity and there is an imminent need for remediation of PAH contaminated soils abounding the several coke oven and town gas sites. Aerobic biological degradation of PAHs is an innovative technology and has shown high decontamination efficiencies, complete mineralization of contaminants, and is environmentally safe. The present study investigates the remediation of PAH contaminated soils achieved using Acinetobacter species and fungal strain Phanerochaete Chrysosporium. The soil used for the experiments was an industrially contaminated soil obtained from Alberta Research Council (ARC) primary cleanup facility, Alberta, Canada. Soil characterization was done using High Performance Liquid Chromatography (HPLC) to qualitatively and quantitatively determine the contaminants in the soil. Artificially contaminated soil was also used for some experiments. All the experiments were conducted under completely mixed conditions with suitable oxygen and nutrient amendments. The removal efficiency obtained for various PAHs using the two microorganisms was compared.

  14. ISOCELL{trademark} proof-of-concept for retrieval of wastes and contaminated soil

    SciTech Connect

    Chatwin, T.D.; Krieg, R.K.

    1992-08-01

    ISOCELL{sup TM} cryogenic technology is designed to immobilize buried hazardous, radioactive, and mixed waste and contaminated soil by creating a block of frozen waste and soil that can be safely retrieved, stored, transported, and treated with a minimum of dust or aerosol production. A ``proof-of-concept`` test of the ISOCELL process was conducted in clean soil by RKK, Ltd., for the Idaho National Engineering Laboratory (INEL). Results indicate ISOCELL technology successfully froze moist soil into a solid block capable of being lifted and retrieved. Test conditions were compared to characteristics of possible buried waste sites in the INEL.

  15. ISOCELL trademark proof-of-concept for retrieval of wastes and contaminated soil

    SciTech Connect

    Chatwin, T.D. ); Krieg, R.K. )

    1992-01-01

    ISOCELL{sup TM} cryogenic technology is designed to immobilize buried hazardous, radioactive, and mixed waste and contaminated soil by creating a block of frozen waste and soil that can be safely retrieved, stored, transported, and treated with a minimum of dust or aerosol production. A proof-of-concept'' test of the ISOCELL process was conducted in clean soil by RKK, Ltd., for the Idaho National Engineering Laboratory (INEL). Results indicate ISOCELL technology successfully froze moist soil into a solid block capable of being lifted and retrieved. Test conditions were compared to characteristics of possible buried waste sites in the INEL.

  16. Bioremediation of petroleum contaminated soil using vegetation. A microbial study

    SciTech Connect

    Lee, E.; Banks, M.K. )

    1993-12-01

    The degradation of selected petroleum hydrocarbons in the rhizosphere of alfalfa was investigated in a greenhouse experiment. Petroleum contaminated and uncontaminated soils were spiked with 100 ppm of polynuclear aromatic and aliphatic hydrocarbons. Unspiked, uncontaminated soil was used as a control. Microbial counts for soils with and without plants for each soil treatment were performed 4, 8, 16, and 24 weeks after planting. Microbial numbers were substantially greater in soil with plants when compared to soil containing no plants, indicating that plant roots enhanced microbial populations in contaminated soil. Soil treatments had no effect on microbial numbers in the presence of plants. 12 refs., 3 figs., 1 tab.

  17. Frozen Soil Barrier. Subsurface Contaminants Focus Area. OST Reference No. 51

    SciTech Connect

    None, None

    1999-09-01

    Problem: Hazardous and radioactive materials have historically been disposed of at the surface during operations at Department of Energy facilities. These contaminants have entered the subsurface, contaminating soils and groundwater resources. Remediation of these groundwater plumes using the baseline technology of pump and treat is expensive and takes a long time to complete. Containment of these groundwater plumes can be alternative or an addition to the remediation activities. Standard containment technologies include slurry walls, sheet piling, and grouting. These are permanent structures that once installed are difficult to remove. How It Works: Frozen Soil Barrier technology provides a containment alternative, with the key difference being that the barrier can be easily removed after a period of time, such as after the remediation or removal of the source is completed. Frozen Soil Barrier technology can be used to isolate and control the migration of underground radioactive or other hazardous contaminants subject to transport by groundwater flow. Frozen Soil Barrier technology consists of a series of subsurface heat transfer devices, known as thermoprobes, which are installed around a contaminant source and function to freeze the soil pore water. The barrier can easily be maintained in place until remediation or removal of the contaminants is complete, at which time the barrier is allowed to thaw.

  18. BIOREMEDIATION OF URANIUM CONTAMINATED SOILS AND WASTES.

    SciTech Connect

    FRANCIS,A.J.

    1998-09-17

    Contamination of soils, water, and sediments by radionuclides and toxic metals from uranium mill tailings, nuclear fuel manufacturing and nuclear weapons production is a major concern. Studies of the mechanisms of biotransformation of uranium and toxic metals under various microbial process conditions has resulted in the development of two treatment processes: (i) stabilization of uranium and toxic metals with reduction in waste volume and (ii) removal and recovery of uranium and toxic metals from wastes and contaminated soils. Stabilization of uranium and toxic metals in wastes is accomplished by exploiting the unique metabolic capabilities of the anaerobic bacterium, Clostridium sp. The radionuclides and toxic metals are solubilized by the bacteria directly by enzymatic reductive dissolution, or indirectly due to the production of organic acid metabolites. The radionuclides and toxic metals released into solution are immobilized by enzymatic reductive precipitation, biosorption and redistribution with stable mineral phases in the waste. Non-hazardous bulk components of the waste such as Ca, Fe, K, Mg and Na released into solution are removed, thus reducing the waste volume. In the second process uranium and toxic metals are removed from wastes or contaminated soils by extracting with the complexing agent citric acid. The citric-acid extract is subjected to biodegradation to recover the toxic metals, followed by photochemical degradation of the uranium citrate complex which is recalcitrant to biodegradation. The toxic metals and uranium are recovered in separate fractions for recycling or for disposal. The use of combined chemical and microbiological treatment process is more efficient than present methods and should result in considerable savings in clean-up and disposal costs.

  19. [The features of radioactive contamination of small birds in Chernobyl zone in 2003-2005].

    PubMed

    Gashchak, S P; Makliuk, Iu A; Maksimenko, A M; Maksimenko, V M; Martynenko, V I; Chizhevskiĭ, I V; Bondar'kov, M D; Mousseau, T A

    2008-01-01

    Radioactive contamination of small birds (484 individuals, 44 species) was investigated in the Chernobyl zone (Ukraine) in 2003-2005. Values variation of 90Sr and of 137Cs activity concentration reached 3-4 orders of magnitude even in one site, and maximum values amounted to hundreds Bq/g at the central plots of the zone. The biggest contamination is appropriate to birds in breeding season and to settled species, whilst migrants are the "cleanest". Change of contamination within a year reflects seasonal and short-term changes in birds diet and in behaviour. During breeding season females have higher activity concentration of 90Sr, while on 137Cs accumulation sexual differences are absent. In other seasons radioactive contamination of male and female does not differ if they live in similar conditions and have similar migratory behavior. Young birds during fledging and just after, as a rule, have higher levels of 90Sr contamination than adults, and actually do not differ on 137Cs accumulation. On a set of own and published data, it was assumed, that in small birds the half-life period of 137Cs extraction amounts to 1-2 days, and 90Sr- 5-10 days, and dynamic equilibrium of the radionuclides turnover in organism is reached over 4-7 and 17-34 days, respectively, after the birds arrival on the contaminated site. Among 44 studied species, those who search invertebrates in soil top layer or forest litter (thrushes). have noticeably higher accumulation of 90Sr and of 137Cs. Specific differences of radionuclides accumulation for the rest birds were not revealed due to small sample sizes of the species. PMID:18666578

  20. PROSPECTS FOR IN SITU CHEMICAL TREATMENT FOR CONTAMINATED SOIL

    EPA Science Inventory

    Treating large volumes of contaminated soil at Superfund sites is costly. he Superfund Amendments and Reauthorization Act (SARA), and the Resource Conservation and Recovery Act (RCRA) have provisions, which regulate the removal treatment, and ultimate disposal of contaminated soi...

  1. REVIEW OF SEPARATION TECHNOLOGIES FOR TREATING PESTICIDE-CONTAMINATED SOIL

    EPA Science Inventory

    Pesticide contamination results from manufacturing, improper storage, handling, or disposal of pesticides, and from agricultural processes. Since most pesticides are mixtures of different compounds, selecting a remedy for pesticide-contaminated soils can be a complicated process....

  2. Soils as a buffer of contaminants in catchments

    NASA Astrophysics Data System (ADS)

    Evrard, Olivier

    2014-05-01

    Human activities deliver large quantities of contaminants into the environment through atmospheric emissions or direct releases. As many of those contaminants are particle-reactive, they bind strongly to the finest particles or on their organic matter fraction once they deposit onto soils. Contaminants may subsequently migrate in depth of the soil depending on their physico-chemical characteristics. They may also be redistributed along hillslopes in association with particles during soil erosion events and may be subsequently supplied to rivers, preventing to meet the international environmental targets (e.g. in the framework of the EU Water Framework Directive). In regions where soil erosion rates are low to moderate, a large quantity of particle-reactive contaminants may accumulate in soils that constitute a reservoir of pollutants that may be delivered to rivers during decades or centuries. This session will focus on the specific role played by soils as a reservoir of contaminants at the catchment scale. A better understanding of this role and a quantification of the persistence of contaminants in this reservoir will provide crucial insights to guide the implementation of efficient mitigation measures. Contributions to this session may address any aspect of particle-borne contaminant transfer at the catchment scale, with an emphasis on the role played by soils in their storage and transfer. Field-based or modeling studies may focus either on specific pollutants or on a wider range of substances, e.g. metals, radionuclides, organic contaminants. Key themes may include: • Contaminant budget at the hillslope vs. the catchment scales; • Evaluation of the contribution of the regional vs. local contamination sources; • Evaluation of the contaminant removal from soils by degradation vs. soil erosion; • Quantifying the persistence of contaminants in soils; • Discrimination between the legacy and the contemporary supply of contaminants to soils.

  3. Managing Groundwater Radioactive Contamination at the Daiichi Nuclear Plant.

    PubMed

    Marui, Atsunao; Gallardo, Adrian H

    2015-07-01

    The Great East Japan Earthquake and tsunami of March 2011 severely damaged three reactors at the Fukushima Daiichi nuclear power station, leading to a major release of radiation into the environment. Groundwater flow through these crippled reactors continues to be one of the main causes of contamination and associated transport of radionuclides into the Pacific Ocean. In this context, a number of strategies are being implemented to manage radioactive pollution of the water resources at the nuclear plant site. Along with water treatment and purification, it is critical to restrict the groundwater flow to and from the reactors. Thus, the devised strategies combine walls containment, bores abstraction, infiltration control, and the use of tanks for the temporary storage of contaminated waters. While some of these techniques have been previously applied in other environments, they have never been tested at such a large scale. Therefore, their effectiveness remains to be seen. The present manuscript presents an overview of the methods being currently implemented to manage groundwater contamination and to mitigate the impact of hydrological pathways in the dispersion of radionuclides at Fukushima. PMID:26197330

  4. Fluvial Placement of Radioactive Contaminants a Weldon Spring Case Study

    SciTech Connect

    Meier, J.

    2002-02-26

    The operation of the Weldon Spring Uranium Feed Materials Plant in St. Charles, MO between 1958 and 1966 resulted in the migration and emplacement of radioactive contaminants into surface water drainage systems. Multiple drainage systems, receiving from a variety of waste discharge points, combined to create unique and unexpected depositional environment. Discovery and investigation of the depositional environments was a significant technical challenge due to the complex nature of sediment movement and emplacement. The objective of this investigation was to show that application of the knowledge of geomorphic processes is an essential element of a complete stream characterization, pursuant to risk analysis and remediation. This paper sets out to describe many of the expected and unexpected findings of the investigations by the Weldon Spring Site Remedial Action Project (WSSRAP) into the placement and rework of contaminated sediments in stream systems. Information from this paper will be useful to other agencies and contractor personnel faced with the challenge of locating and quantifying contaminated sediments in seemingly haphazard fluvial depositional conditions.

  5. Managing Groundwater Radioactive Contamination at the Daiichi Nuclear Plant

    PubMed Central

    Marui, Atsunao; Gallardo, Adrian H.

    2015-01-01

    The Great East Japan Earthquake and tsunami of March 2011 severely damaged three reactors at the Fukushima Daiichi nuclear power station, leading to a major release of radiation into the environment. Groundwater flow through these crippled reactors continues to be one of the main causes of contamination and associated transport of radionuclides into the Pacific Ocean. In this context, a number of strategies are being implemented to manage radioactive pollution of the water resources at the nuclear plant site. Along with water treatment and purification, it is critical to restrict the groundwater flow to and from the reactors. Thus, the devised strategies combine walls containment, bores abstraction, infiltration control, and the use of tanks for the temporary storage of contaminated waters. While some of these techniques have been previously applied in other environments, they have never been tested at such a large scale. Therefore, their effectiveness remains to be seen. The present manuscript presents an overview of the methods being currently implemented to manage groundwater contamination and to mitigate the impact of hydrological pathways in the dispersion of radionuclides at Fukushima. PMID:26197330

  6. System for the removal of contaminant soil-gas vapors

    DOEpatents

    Weidner, Jerry R.; Downs, Wayne C.; Kaser, Timothy G.; Hall, H. James

    1997-01-01

    A system extracts contaminated vapors from soil or other subsurface regions by using changes in barometric pressure to operate sensitive check valves that control air entry and removal from wells in the ground. The system creates an efficient subterranean flow of air through a contaminated soil plume and causes final extraction of the contaminants from the soil to ambient air above ground without any external energy sources.

  7. System for the removal of contaminant soil-gas vapors

    DOEpatents

    Weidner, J.R.; Downs, W.C.; Kaser, T.G.; Hall, H.J.

    1997-12-16

    A system extracts contaminated vapors from soil or other subsurface regions by using changes in barometric pressure to operate sensitive check valves that control air entry and removal from wells in the ground. The system creates an efficient subterranean flow of air through a contaminated soil plume and causes final extraction of the contaminants from the soil to ambient air above ground without any external energy sources. 4 figs.

  8. Soil contamination in China: current status and mitigation strategies.

    PubMed

    Zhao, Fang-Jie; Ma, Yibing; Zhu, Yong-Guan; Tang, Zhong; McGrath, Steve P

    2015-01-20

    China faces great challenges in protecting its soil from contamination caused by rapid industrialization and urbanization over the last three decades. Recent nationwide surveys show that 16% of the soil samples, 19% for the agricultural soils, are contaminated based on China’s soil environmental quality limits, mainly with heavy metals and metalloids. Comparisons with other regions of the world show that the current status of soil contamination, based on the total contaminant concentrations, is not worse in China. However, the concentrations of some heavy metals in Chinese soils appear to be increasing at much greater rates. Exceedance of the contaminant limits in food crops is widespread in some areas, especially southern China, due to elevated inputs of contaminants, acidic nature of the soil and crop species or cultivars prone to heavy metal accumulation. Minimizing the transfer of contaminants from soil to the food chain is a top priority. A number of options are proposed, including identification of the sources of contaminants to agricultural systems, minimization of contaminant inputs, reduction of heavy metal phytoavailability in soil with liming or other immobilizing materials, selection and breeding of low accumulating crop cultivars, adoption of appropriate water and fertilizer management, bioremediation, and change of land use to grow nonfood crops. Implementation of these strategies requires not only technological advances, but also social-economic evaluation and effective enforcement of environmental protection law. PMID:25514502

  9. The effect of contaminant aging upon soil washing removal efficiencies for lead contaminated soils

    SciTech Connect

    Cline, S.R.; Reed, B.E.; Moore, R.E.

    1994-10-01

    The objective of this research was to investigate lead removal efficiencies from various soils using a variety of washing solutions. Most soil types have a strong affinity for lead. Thus, it is plausible to expect washing solutions that are capable of removing lead could also remove other divalent heavy metals. Four soil samples from the eastern US were collected and characterized for this study. The study soils were then spiked to approximate lead concentrations of 1,000 and 10,000 mg Pb/kg soil. The efficiencies of six washing solutions in removing lead from the contaminated soils were then investigated via lab-scale batch washing experiments. Unlike current field-scale soil washing practices, all particle size fractions were washed and recovered in these experiments. (Solutions investigated include: tap water, HCl, EDTA, HNO{sub 3}, CH{sub 3}COOH, and CaCl{sub 2}.) In order to examine the effect of aging upon soil washing efficiencies, some of the spiked soils were washed a second time after an aging period of nearly 2 years.

  10. BIOREMEDIATION OF MIXED VAPOR PHASE CONTAMINANTS FROM SOILS AND GROUNDWATER

    EPA Science Inventory

    Soil vapor phase contaminants commonly include combinations of chlorinated ethenes and petroleum hydrocarbons. Many chlorinated ethenes and petroleum hydrocarbons are readily degradable by a range of aerobic soil microorganisms, making the use of biological systems for degrading ...

  11. Mouse Assay for Determination of Arsenic Bioavailability in Contaminated Soils

    EPA Science Inventory

    Background: Accurate assessment of human exposure estimates from arsenic-contaminated soils depends upon estimating arsenic (As) soil bioavailability. Development of bioavailability assays provides data needed for human health risk assessments and supports development and valida...

  12. Potential airborne release from soil-working operations in a contaminated area

    SciTech Connect

    Sutter, S.L.

    1980-08-01

    Experiments were performed to provide an indication of how much material could be made airborne during soil-working operations in a contaminated area. Approximately 50 kg of contaminated soil were collected, dried, and mixed, and particle size distribution and /sup 137/Cs content were characterized. In four experiments performed in a 2 ft x 2 ft wind tunnel at the Radioactive Aerosol Release Test Facility, soil was pumped into an airstream moving at 3.2, 10.4, 15.2, and 20 mph. These experiments were designed to maximize airborne releases by fluidizing the soil as it was pumped into the wind tunnel. Thus the airborne releases should represent upper limit values for soil-working operations. Airborne concentration and particle size samples were collected and all of the material deposited downstream was collected to calculate a mass balance. The fraction airborne was calculated using these measurements.

  13. Levels of sup 137 Cs and natural radioactivity in Saudi Arabian soil

    SciTech Connect

    Abulfarai, W.; Abdul-Majid, S. )

    1991-01-01

    After the Chernobyl accident, there was concern about contamination from the radioactive plume reaching Saudi Arabia. Cesium-137 concentration in the soil was measured to determine the degree of contamination from the accident. The concentrations of {sup 40}K, {sup 214}Bi, and {sup 228}Ac were determined as well. Bismuth-214 is a member of the {sup 238}U series, while {sup 228}Ac is from the {sup 238}Th series. Each of these isotopes emits several well-resolved photons of relatively high intensity per disintegration.

  14. Transport of radioactive ions in soil by electrokinetics

    SciTech Connect

    Buehler, M.F.; Surma, J.E.; Virden, J.W.

    1994-10-01

    An electrokinetic approach is being evaluated for in situ soil remediation at the Hanford Site in Richland, Washington. This approach uses an applied electric field to induce transport of both radioactive and hazardous waste ions in soil. The work discussed in this paper involves the development of a new method to monitor the movement of the radioactive ions within the soil during the electrokinetic process. A closed cell and a gamma counter were used to provide iii situ measurements of {sup 137}Cs and {sup 60}Co movement in Hanford soil. Preliminary results show that for an applied potential of 200 V over approximately 200 hr, {sup 137}Cs and {sup 60}60 were transported a distance of 4 to 5 in. The monitoring technique demonstrated the feasibility of using electrokinetics for soil separation applications.

  15. Testing amendments for remediation of military range contaminated soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Military range soils are often strongly contaminated with metals. Information on effectiveness of remediation techniques on these soils is scarce. We tested effectiveness of compost and mineral treatments for remediation of military range soil collected in Aberdeen, MD. The soil was barren due to...

  16. Comprehensive methodology for ecological risk assessment of contaminated soils

    SciTech Connect

    Kuperman, R.G.

    1994-12-31

    Development of a comprehensive methodology for ecological risk assessment and monitoring of contaminated soils is essential to assess the impacts of environmental contaminants on soil community and biologically-mediated processes in soil. The proposed four-step plan involves (1) a thorough survey of the soil community to establish biodiversity and a base-line community structure, (2) toxicity trials on indicator species and whole soil invertebrate communities, (3) laboratory and field tests on indicator processes and (4) the use of statistical and simulation models to ascertain changes in the soil ecosystems. This methodology was used in portions of the US Army`s Aberdeen Proving Ground, Maryland as part of an ecological risk assessment. Previous soil analyses showed extensive surface soil contamination with metals, nitrate and PCBs. Preliminary results from field surveys of soil invertebrate communities showed significant reductions in total abundance of animals, reductions in the abundance of several taxonomic and functional groups of soil invertebrates, and changes in the activity of epigeic arthropods in contaminated areas when compared with the local ``background`` area. Laboratory tests also demonstrated that microbial activity and success of egg hatching of ground beetle Harpalus pensylvanicus were reduced in contaminated soils. These results suggest that impacts to soil ecosystems should be explicitly considered in ecological risk assessment. The proposed comprehensive methodology appears to offer an efficient and potentially cost saving tool for remedial investigations of contaminated sites.

  17. Genetics of cattails in radioactively contaminated areas around Chornobyl.

    PubMed

    Tsyusko, Olga V; Smith, Michael H; Oleksyk, Taras K; Goryanaya, Julia; Glenn, Travis C

    2006-08-01

    Research on populations from radioactively contaminated areas around Chornobyl has produced ambiguous results for the presence of radiation effects. More studies are needed to provide information on whether radiation exposure at Chornobyl significantly affected genetic diversity in natural populations of various taxa. Eleven and nine variable microsatellite loci were used to test for differences in genetic diversity between reference and Chornobyl populations of two cattail species (Typha angustifolia and Typha latifolia, respectively) from Ukraine. Our purpose was to determine whether radiation had a significant impact on genetic diversities of the Chornobyl Typha populations, or if their genetic composition might be better explained by species demography and/or changes in population dynamics, mainly in sexual and asexual reproduction. Populations closest to the reactor had increased genetic diversities and high number of genets, which likely were due to factors other than radiation including increased gene flow among Chornobyl populations, enhanced sexual reproduction within populations, and/or origin of the genets from seed bank. Both Typha species also demonstrated small but significant effects associated with latitude, geographical regions, and watersheds. Typha's demography in Ukraine possibly varies with these three factors, and the small difference between Chornobyl and reference populations of T. latifolia detected after partitioning the total genetic variance between them is probably due primarily to these factors. However, the positive correlations of several genetic characteristics with radionuclide concentrations suggest that radiation may have also affected genetics of Chornobyl Typha populations but much less than was expected considering massive contamination of the Chornobyl area. PMID:16842431

  18. Performance study and influence of radiation emission energy and soil contamination level on γ-radiation shielding of stabilised/solidified radionuclide-polluted soils.

    PubMed

    Falciglia, Pietro P; Puccio, Valentina; Romano, Stefano; Vagliasindi, Federico G A

    2015-05-01

    This work focuses on the stabilisation/solidification (S/S) of radionuclide-polluted soils at different (232)Th levels using Portland cement alone and with barite aggregates. The potential of S/S was assessed applying a full testing protocol and calculating γ-radiation shielding (γRS) index, that included the measurement of soil radioactivity before and after the S/S as a function of the emission energy and soil contamination level. The results indicate that setting processes are strongly dependent on the contaminant concentration, and for contamination level higher than 5%, setting time values longer than 72 h. The addition of barite aggregates to the cement gout leads to a slight improvement of the S/S performance in terms of durability and contaminant leaching but reduces the mechanical resistance of the treated soils samples. Barite addition also causes an increase in the γ-rays shielding properties of the S/S treatment up to about 20%. Gamma-ray measurements show that γRS strongly depends on the energy, and that the radioactivity with the contamination level was governed by a linear trend, while, γRS index does not depend on the radionuclide concentration. Results allow the calculated γRS values and those available from other experiments to be applied to hazard radioactive soil contaminations. PMID:25710096

  19. Public perceptions of a radioactively contaminated site: concerns, remediation preferences, and desired involvement.

    PubMed Central

    Feldman, D L; Hanahan, R A

    1996-01-01

    A public attitudes survey was conducted in neighborhoods adjacent to a radioactively contaminated site whose remediation is now under the auspices of the U.S. Department of Energy's Formerly Utilized Sites Remedial Action Program (FUSRAP). The survey's purpose was to ascertain levels of actual and desired public involvement in the remediation process; to identify health, environmental, economic, and future land-use concerns associated with the site; and to solicit remediation strategy preferences. Surface water and groundwater contamination, desire for public involvement, and potential health risks were found to be the most highly ranked site concerns. Preferred remediation strategies included treatment of contaminated soil and excavation with off-site disposal. Among on-site remediation strategies, only institutional controls that leave the site undisturbed and do not require additional excavation of materials were viewed favorably. Cost of remediation appeared to influence remediation strategy preference; however, no strategy was viewed as a panacea. Respondents were also concerned with protecting future generations, better assessment of risks to health and the environment, and avoiding generation of additional contaminated materials. PMID:9118878

  20. ELECTROCHEMICAL PROCESSES FOR IN-SITU TREATMENT OF CONTAMINATED SOILS

    EPA Science Inventory

    This project will study electrochemical processes for the in situ treatment of soils contaminated by mixed wastes, i.e., organic and inorganic. Soil samples collected from selected DOE waste sites will be characterized for specific organic and metal contaminants and hydraulic per...

  1. BIOAVAILABILITY OF METALS IN CONTAMINATED SOIL AND DUST

    EPA Science Inventory

    Due to widespread metal contamination, it is necessary to characterize soils suspected of metal contamination and determine if the metal levels in these soils pose a hazard. Metal toxicity is often not directly related to the total concentration of metals present due to a numb...

  2. Operating and life-cycle costs for uranium-contaminated soil treatment technologies

    SciTech Connect

    Douthat, D.M.; Armstrong, A.Q.; Stewart, R.N.

    1995-09-01

    The development of a nuclear industry in the US required mining, milling, and fabricating a large variety of uranium products. One of these products was purified uranium metal which was used in the Savannah River and Hanford Site reactors. Most of this feed material was produced at the US Department of Energy (DOE) facility formerly called the Feed Materials Production Center at Fernald, Ohio. During operation of this facility, soils became contaminated with uranium from a variety of sources. To avoid disposal of these soils in low-level radioactive waste burial sites, increasing emphasis has been placed on the remediating soils contaminated with uranium and other radionuclides. To address remediation and management of uranium-contaminated soils at sites owned by DOE, the DOE Office of Technology Development (OTD) evaluates and compares the versatility, efficiency, and economics of various technologies that may be combined into systems designed to characterize and remediate uranium-contaminated soils. Each technology must be able to (1) characterize the uranium in soil, (2) decontaminate or remove uranium from soil, (3) treat or dispose of resulting waste streams, (4) meet necessary state and federal regulations, and (5) meet performance assessment objectives. The role of the performance assessment objectives is to provide the information necessary to conduct evaluations of the technologies. These performance assessments provide the basis for selecting the optimum system for remediation of large areas contaminated with uranium. One of the performance assessment tasks is to address the economics of full-scale implementation of soil treatment technologies. The cost of treating contaminated soil is one of the criteria used in the decision-making process for selecting remedial alternatives.

  3. Evaporation of petroleum products from contaminated soils

    SciTech Connect

    Kang, S.H.; Oulman, C.S.

    1996-05-01

    Bioremediation can remove petroleum products from soil that has been contaminated by leaking underground storage tanks, but abiotic processes such as evaporation can contribute significantly to the overall removal process. The mathematical model described in this paper was developed to predict the evaporation rate of volatile liquids from petroleum-contaminated sand. The model is based on simple concepts relating to molecular diffusion embodied in the theory underlying the estimation of binary diffusivities using measurements made with an Arnold diffusion cell. The model in its simplified form indicates that the rate of evaporation for a particular volatile liquid is proportional to the square root of the product of diffusivity and partial pressure divided by the molecular weight of the liquid. This in part explains why evaporative losses from sand are so much higher for gasoline than for diesel fuel. The model also shows that the time for evaporation is directly proportional to the square of the depth dried out and inversely proportional to the vapor pressure of the volatile liquid. The model was tested using gravimetric measurements of the evaporation of n-heptane, unleaded gasoline, and diesel fuel from sand under laboratory conditions.

  4. Geochemical information for sites contaminated with low-level radioactive wastes. III. Weldon Spring Storage Site

    SciTech Connect

    Seeley, F.G.; Kelmers, A.D.

    1985-02-01

    The Weldon Spring Storage Site (WSSS), which includes both the chemical site and the quarry, became radioactively contaminated as the result of wastes that were being stored from operations to recover uranium from pitchblende ores in the 1940s and 1950s. The US Department of Energy (DOE) is considering various remedial action options for the WSSS. This report describes the results of geochemical investigations carried out at Oak Ridge National Laboratory (ORNL) to support these activities and to help quantify various remedial action options. Soil and groundwater samples were characterized, and uranium and radium sorption ratios were measured in site soil/groundwater systems by batch contact methodology. Soil samples from various locations around the raffinate pits were found to contain major amounts of silica, along with illite as the primary clay constituent. Particle sizes of the five soil samples were variable (50% distribution point ranging from 12 to 81 ..mu..m); the surface areas varied from 13 to 62 m/sup 2//g. Elemental analysis of the samples showed them to be typical of sandy clay and silty clay soils. Groundwater samples included solution from Pit 3 and well water from Well D. Anion analyses showed significant concentrations of sulfate and nitrate (>350 and >7000 mg/L, respectively) in the solution from Pit 3. These anions were also present in the well water, but in lower concentrations. Uranium sorption ratios for four of the soil samples contacted with the solution from Pit 3 were moderate to high (approx. 300 to approx. 1000 mL/g). The fifth sample had a ratio of only 12 mL/g. Radium sorption ratios for the five samples were moderate to high (approx. 600 to approx. 1000 mL/g). These values indicate that soil at the WSSS may show favorable retardation of uranium and radium in the groundwater. 13 references, 13 figures, 10 tables.

  5. Background in the context of land contaminated with naturally occurring radioactive material.

    PubMed

    Read, D; Read, G D; Thorne, M C

    2013-06-01

    The financial implications of choosing a particular threshold for clearance of radioactively contaminated land are substantial, particularly when one considers the volume of naturally occurring radioactive material (NORM) created each year by the production and combustion of fossil fuels and the exploitation of industrial minerals. Inevitably, a compromise needs to be reached between the level of environmental protection sought and the finite resources available for remediation. In the case of natural series radionuclides, any anthropogenic input is always superimposed on the inventory already present in the soil; this 'background' inventory is conventionally disregarded when assessing remediation targets. Unfortunately, the term is not well defined and the concept of 'background dose' is open to alternative interpretations. In this paper, we address the issue of natural background from a geochemical rather than from a solely radiological perspective, illustrating this with an example from the china clay industry. We propose a simple procedure for decision making based on activity concentrations of primordial radionuclides and their progeny. Subsequent calculations of dose need to take into account the mineralogical and chemical characteristics of the contamination, which in the case of NORM are invariably reflected in uranium series disequilibrium. PMID:23519083

  6. Study on magnetic separation for decontamination of cesium contaminated soil by using superconducting magnet

    NASA Astrophysics Data System (ADS)

    Igarashi, Susumu; Nomura, Naoki; Mishima, Fumihito; Akiyama, Yoko

    2014-09-01

    The accident of Fukushima Daiichi nuclear power plant caused the diffusion of radioactive cesium over the wide area. We examined the possibility of applying magnetic separation method using the superconducting magnet, which can process a large amount of the soil in high speed, to the soil decontamination and volume reduction of the radioactive cesium contaminated soil. Clay minerals are classified as 2:1 and 1:1 types by the difference of their layer structures, and these types of minerals are respectively paramagnetic and diamagnetic including some exception. It is known that most of the radioactive cesium is strongly adsorbed on the clay, especially on 2:1 type clay minerals. It is expected that the method which can separate only 2:1 type clay minerals selectively from the mixture clay minerals can enormously contribute to the volume reduction of the contaminated soil. In this study, the components in the clay before and after separation were evaluated to estimate the magnetic separation efficiency by using X-ray diffraction. From the results, the decontamination efficiency and the volume reduction ratio were estimated in order to examine the appropriate separation conditions for the practical decontamination of the soil.

  7. Radon Emanation from NORM-Contaminated Pipe Scale, Soil, and Sediment at Petroleum Industry Sites

    SciTech Connect

    Rood, A.S.; White, G.J.

    1999-10-07

    This report describes a study of radon (Rn) emanation from pipe scale and soil samples contaminated with naturally occurring radioactive material (NORM). Samples were collected at petroleum production sites in Oklahoma, Michigan, Kentucky, and Illinois. For comparison, data are also presented from preliminary studies conducted at sites in Texas and Wyoming. All samples collected were analyzed for their Rn emanation fraction, defined as the fraction of 222Rn produced that enters the interconnected pore space within a medium contaminated with 226Ra before the 222Rn undergoes radioactive decay. This measure represents one of the important parameters that determine the overall Rn activity flux from any solid medium. The goal of this project was to determine whether Rn emanation from pipe scale and soil is similar to emanation from uranium mill tailings.

  8. Current methods for evaluating the bioavailability of chemicals from contaminated soils using soil invertebrates

    SciTech Connect

    Lanno, R.P.

    1995-12-31

    Contaminated soils are an extremely complex, variable matrix where many modifying factors of toxicity (e.g., particle size, organic matter content) alter the availability of chemicals to biota. Although many methods have been standardized for assessing the toxicity of contaminated soils to invertebrates and plants, few studies have actually addressed the issue of contaminant bioavailability from soils. Since bioavailability is a measure of uptake of contaminants from the soil by living organisms, one approach to determining bioavailability is to measure residues of contaminants in biota. Body residues related to a specific lethal or sublethal toxicity endpoint offer the unique opportunity to relate bioavailability to biological response. This paper will present an overview of the use of body residues in assessing the bioavailability of soil contaminants by earthworms and soil arthropods. The applications of body residues in the development of soil quality guidelines will also be discussed.

  9. Radioactive contamination screening with laser-induced fluorescence

    SciTech Connect

    Sheely, R.; Di Benedetto, J.

    1994-06-01

    The ability to induce, detect and discriminate fluorescence of uranium oxides makes available new capabilities for screening the surface of large complex facilities for uranium. This paper will present the results of field tests evaluate laser-induced fluorescence (LIF) as a contamination screening tool and report on the progress to produce a field portable instrument for uranium surveys on exposed surfaces. The principal effect is to illuminate the surface of an object or an area with a remotely-located light source, and to evaluate the re-radiated emission energy. A gated intensified CCD camera was used with ultraviolet (UV) laser excitation to discriminate the phosphorescent (persistent) green uranium emission from the prompt background fluorescence which results from excitation of plants, concrete, soils, and other background materials.

  10. Urban Community Gardeners' Knowledge and Perceptions of Soil Contaminant Risks

    PubMed Central

    Kim, Brent F.; Poulsen, Melissa N.; Margulies, Jared D.; Dix, Katie L.; Palmer, Anne M.; Nachman, Keeve E.

    2014-01-01

    Although urban community gardening can offer health, social, environmental, and economic benefits, these benefits must be weighed against the potential health risks stemming from exposure to contaminants such as heavy metals and organic chemicals that may be present in urban soils. Individuals who garden at or eat food grown in contaminated urban garden sites may be at risk of exposure to such contaminants. Gardeners may be unaware of these risks and how to manage them. We used a mixed quantitative/qualitative research approach to characterize urban community gardeners' knowledge and perceptions of risks related to soil contaminant exposure. We conducted surveys with 70 gardeners from 15 community gardens in Baltimore, Maryland, and semi-structured interviews with 18 key informants knowledgeable about community gardening and soil contamination in Baltimore. We identified a range of factors, challenges, and needs related to Baltimore community gardeners' perceptions of risk related to soil contamination, including low levels of concern and inconsistent levels of knowledge about heavy metal and organic chemical contaminants, barriers to investigating a garden site's history and conducting soil tests, limited knowledge of best practices for reducing exposure, and a need for clear and concise information on how best to prevent and manage soil contamination. Key informants discussed various strategies for developing and disseminating educational materials to gardeners. For some challenges, such as barriers to conducting site history and soil tests, some informants recommended city-wide interventions that bypass the need for gardener knowledge altogether. PMID:24516570

  11. Urban community gardeners' knowledge and perceptions of soil contaminant risks.

    PubMed

    Kim, Brent F; Poulsen, Melissa N; Margulies, Jared D; Dix, Katie L; Palmer, Anne M; Nachman, Keeve E

    2014-01-01

    Although urban community gardening can offer health, social, environmental, and economic benefits, these benefits must be weighed against the potential health risks stemming from exposure to contaminants such as heavy metals and organic chemicals that may be present in urban soils. Individuals who garden at or eat food grown in contaminated urban garden sites may be at risk of exposure to such contaminants. Gardeners may be unaware of these risks and how to manage them. We used a mixed quantitative/qualitative research approach to characterize urban community gardeners' knowledge and perceptions of risks related to soil contaminant exposure. We conducted surveys with 70 gardeners from 15 community gardens in Baltimore, Maryland, and semi-structured interviews with 18 key informants knowledgeable about community gardening and soil contamination in Baltimore. We identified a range of factors, challenges, and needs related to Baltimore community gardeners' perceptions of risk related to soil contamination, including low levels of concern and inconsistent levels of knowledge about heavy metal and organic chemical contaminants, barriers to investigating a garden site's history and conducting soil tests, limited knowledge of best practices for reducing exposure, and a need for clear and concise information on how best to prevent and manage soil contamination. Key informants discussed various strategies for developing and disseminating educational materials to gardeners. For some challenges, such as barriers to conducting site history and soil tests, some informants recommended city-wide interventions that bypass the need for gardener knowledge altogether. PMID:24516570

  12. Developing an integration tool for soil contamination assessment

    NASA Astrophysics Data System (ADS)

    Anaya-Romero, Maria; Zingg, Felix; Pérez-Álvarez, José Miguel; Madejón, Paula; Kotb Abd-Elmabod, Sameh

    2015-04-01

    In the last decades, huge soil areas have been negatively influenced or altered in multiples forms. Soils and, consequently, underground water, have been contaminated by accumulation of contaminants from agricultural activities (fertilizers and pesticides) industrial activities (harmful material dumping, sludge, flying ashes) and urban activities (hydrocarbon, metals from vehicle traffic, urban waste dumping). In the framework of the RECARE project, local partners across Europe are focusing on a wide range of soil threats, as soil contamination, and aiming to develop effective prevention, remediation and restoration measures by designing and applying targeted land management strategies (van Lynden et al., 2013). In this context, the Guadiamar Green Corridor (Southern Spain) was used as a case study, aiming to obtain soil data and new information in order to assess soil contamination. The main threat in the Guadiamar valley is soil contamination after a mine spill occurred on April 1998. About four hm3 of acid waters and two hm3 of mud, rich in heavy metals, were released into the Agrio and Guadiamar rivers affecting more than 4,600 ha of agricultural and pasture land. Main trace elements contaminating soil and water were As, Cd, Cu, Pb, Tl and Zn. The objective of the present research is to develop informatics tools that integrate soil database, models and interactive platforms for soil contamination assessment. Preliminary results were obtained related to the compilation of harmonized databases including geographical, hydro-meteorological, soil and socio-economic variables based on spatial analysis and stakeholder's consultation. Further research will be modellization and upscaling at the European level, in order to obtain a scientifically-technical predictive tool for the assessment of soil contamination.

  13. Spectral induced polarization signature of contaminated soil

    NASA Astrophysics Data System (ADS)

    Schwartz, N.; Huisman, J. A.; Shefer, I.; Furman, A.

    2012-04-01

    Spectral induced polarization (SIP) signatures of porous media contaminated with non aqueous phase liquids (NAPL) were measured using an accurate impedance meter. The samples were prepared by mixing air-dried sand with 15% by weight of bentonite clay, tap water and either diesel fuel or motor oil. Next, the soil was packed in a column and left for 24 hr before electrical measurements were performed. For all the samples, water saturation was constant (Sw = 0.47) and the NAPL saturation was 0 (control), 5, or 15 percent. Counter-intuitively, the results show that addition of NAPL to the porous media resulted in an increase of the real part of the complex conductivity. Evidently, for each type of contaminant, an increase in the contaminant saturation resulted in an increase in the real part of the conductivity. The imaginary part of the complex conductivity showed a reversed behavior: higher NAPL saturation resulted in a reduction of the imaginary part of the complex conductivity. For both the real and the imaginary part of the complex conductivity, the effect of NAPL on the complex electrical conductivity was more significant for motor oil than for diesel fuel. In addition to the electrical measurements, we also performed an extraction experiment to examine the effect of the presence of NAPL on the electrical conductivity (EC) of the pore water. The results from the extraction experiment showed that addition of NAPL to the porous media resulted in an increase of the pore water EC. We argue that this increase in the real part of the complex conductivity is related to adsorption of organic polar compounds from the NAPL onto the mineral surface and the associated release of inorganic ions from the mineral surface to the pore water. These exchange processes affect both the surface and the pore water conductivity. In addition, we suggest that the decrease in polarization (associated with the imaginary part of the complex conductivity) of the NAPL contaminated porous media

  14. Remediation of contaminated soils and sludges by green plants

    SciTech Connect

    Cunningham, S.D.; Berti, W.R.; Huang, J.W.

    1995-12-31

    The potential of green plants to remove, contain, or render harmless contaminants in soils and sludges is actively being explored in an increasing number of laboratories throughout the world. This approach, which has been termed phytoremediation, exploits plants, soil amendments, and plant-associated microbiota to remediate contaminated soils. As an in situ stabilization technique, soil amendment with fertilizers, biosolids, or certain industrial by-products alters the chemical and physical nature of the contaminant in the soil matrix, thus reducing its available to biological processes. The site is then vegetated with plants that can (1) grow in the resulting soil matrix; (2) reduce leaching through the soil profile by absorbing, sequestering, or degrading residual contaminants in the soil solution; and (3) minimize wind and rain erosion. The process is known as phytostabilization, or simply site stabilization, and borrows heavily on mine reclamation techniques. As a site decontamination technique, the soil is treated to increase the availability of the contaminant to biological processes and then planted with plants that (1) accumulate the contaminant and are harvested for further pollutant destruction, sequestration, or reclamation or (2) use plant or plant-associated microbial processes to destroy the pollutant in situ.

  15. Apparatus for treatment of soils contaminated with organic pollutants

    DOEpatents

    Wickramanayake, Godage B.

    1993-01-01

    An apparatus for treating soil contaminated by organic compounds wherein an ozone containing gas is treated with acid to increase the stability of the ozone in the soil environment and the treated ozone applied to the contaminated soil in a manner adapted to decompose the organic compounds; one embodiment of the apparatus comprises a means to supply ozone as a gas-ozone mixture, a stability means to treat ozone obtained from the supply and distribution means to apply the stabilized gas-ozone to soil. The soil may be treated in situ or may be removed for treatment and refilled.

  16. Relative bioavailability of arsenic contaminated soils in a mouse model

    EPA Science Inventory

    Exposure to As contaminated soils compels extensive soil cleanups so that human health risks are minimized. In order to improve exposure estimates and potentially reduce remediation costs, determination of the bioavailability of As in soils is needed. The objective of this study ...

  17. Control and assessment of the hydrocarbon contamination of Ukrainian soils

    NASA Astrophysics Data System (ADS)

    Miroshnichenko, N. N.

    2008-05-01

    Regularities governing the self-purification of soils from oil hydrocarbons, as well as migration of hydrocarbons, and the effect on the water-physical properties and fertility of soils were revealed in a series of experiments. A system of ecological, economic, and reclamation standards was proposed for regulating economic activities in the case of soil contamination with hydrocarbons.

  18. THE IMPORTANCE OF BIOAVAILABILITY IN REMEDIATION OF METAL CONTAMINATED SOILS

    EPA Science Inventory

    Reduction in exposure to soil metal contamination has typically been accomplished by soil removal and off site disposal, by covering, or by diluting with uncontaminated soil. Cost, logistical concerns, and regulatory requirements associated with excavation and disposal or ex-situ...

  19. Plutonium contamination in soils and sediments at Mayak PA, Russia.

    PubMed

    Skipperud, Lindis; Salbu, Brit; Oughton, Deborah H; Drozcho, Eugeny; Mokrov, Yuri; Strand, Per

    2005-09-01

    The Mayak Production Association (Mayak PA) was established in the late 1940's to produce plutonium for the Soviet Nuclear Weapons Programme. In total, seven reactors and two reprocessing plants have been in operation. Today, the area comprises both military and civilian reactors as well as reprocessing and metallurgical plants. Authorized and accidental releases of radioactive waste have caused severe contamination to the surrounding areas. In the present study, [alpha]-spectrometry and inductively coupled plasma-mass spectrometry (ICP-MS) have been used to determine plutonium activities and isotope ratios in soil and sediment samples collected from reservoirs of the Techa River at the Mayak area and downstream Techa River. The objective of the study was to determine the total inventory of plutonium in the reservoirs and to identify the different sources contributing to the plutonium contamination. Results based on [alpha]-spectrometry and ICP-MS measurements show the presence of different sources and confirmed recent reports of civilian reprocessing at Mayak. Determination of activity levels and isotope ratios in soil and sediment samples from the Techa River support the hypothesis that most of the plutonium, like other radionuclides in the Techa River, originated from the very early waste discharges to the Techa River between 1949 and 1951. Analysis of reservoir sediment samples suggest that about 75% of the plutonium isotopes could have been released to Reservoir 10 during the early weapons production operation of the plant, and that the majority of plutonium in Reservoir 10 originates from discharges from power production or reprocessing. Enhanced 240Pu/239Pu atom ratios in river sediment upper layers (0-2 cm) between 50 and 250 km downstream from the plant indicate a contribution from other, non-fallout sources. PMID:16096501

  20. A simple model to predict the long-term fate of contaminants in unsaturated soils

    SciTech Connect

    Davis, P.A. ); Sheppard, M.I.; Andres, T.H. )

    1993-01-01

    The authors present a model of contaminant transport in unsaturated soils that is suitable for long-term assessments. The model is based on a series of regression equations that represent the predictions of a mechanistic soil model. It therefore reflects the detailed treatment of processes, and the short time and space scales, of its parent code, but can predict root zone concentrations thousands of years in the future in just a few seconds of computer time, on even the simplest machines. The model accounts for transport via leaching and capillary rise, for chemical exchange between solid and liquid phases of the soil, and for losses, such as radioactive decay, gaseous evasion, and root uptake, that can be described as first-order processes. It can be applied to soils that are contaminated at the surface through irrigation or atmospheric deposition, or from below through contact with contaminated groundwater. It was developed to treat soil types and climates typical of the Canadian Shield, but could be modified for other conditions. The authors discuss the parent mechanistic model briefly, and then describe in detail its simplification and reduction to a simple assessment model. The authors show that the assessment model satisfactorily reproduces the predictions of the mechanistic model, which has been extensively validated against observations of contaminant concentrations in soils. A comparison of the model with multicompartment models, which have traditionally been used for assessment purposes, suggests that differences between the two types of models may cause systematic differences in predictions.

  1. Screening of plants for phytoremediation of oil-contaminated soil.

    PubMed

    Ikeura, Hiromi; Kawasaki, Yu; Kaimi, Etsuko; Nishiwaki, Junko; Noborio, Kosuke; Tamaki, Masahiko

    2016-05-01

    Several species of ornamental flowering plants were evaluated regarding their phytoremediation ability for the cleanup of oil-contaminated soil in Japanese environmental conditions. Thirty-three species of plants were grown in oil-contaminated soil, and Mimosa, Zinnia, Gazania, and cypress vine were selected for further assessment on the basis of their favorable initial growth. No significant difference was observed in the above-ground and under-ground dry matter weight of Gazania 180 days after sowing between contaminated and non-contaminated plots. However, the other 3 species of plants died by the 180(th) day, indicating that Gazania has an especially strong tolerance for oil-contaminated soil. The total petroleum hydrocarbon concentration of the soils in which the 4 species of plants were grown decreased by 45-49% by the 180(th) day. Compared to an irrigated plot, the dehydrogenase activity of the contaminated soil also increased significantly, indicating a phytoremediation effect by the 4 tested plants. Mimosa, Zinnia, and cypress vine all died by the 180(th) day after seeding, but the roots themselves became a source of nutrients for the soil microorganisms, which led to a phytoremediation effect by increase in the oil degradation activity. It has been indicated that Gazania is most appropriate for phytoremediation of oil-contaminated soil. PMID:26587892

  2. Biological Treatment of Petroleum in Radiologically Contaminated Soil

    SciTech Connect

    BERRY, CHRISTOPHER

    2005-11-14

    This chapter describes ex situ bioremediation of the petroleum portion of radiologically co-contaminated soils using microorganisms isolated from a waste site and innovative bioreactor technology. Microorganisms first isolated and screened in the laboratory for bioremediation of petroleum were eventually used to treat soils in a bioreactor. The bioreactor treated soils contaminated with over 20,000 mg/kg total petroleum hydrocarbon and reduced the levels to less than 100 mg/kg in 22 months. After treatment, the soils were permanently disposed as low-level radiological waste. The petroleum and radiologically contaminated soil (PRCS) bioreactor operated using bioventing to control the supply of oxygen (air) to the soil being treated. The system treated 3.67 tons of PCRS amended with weathered compost, ammonium nitrate, fertilizer, and water. In addition, a consortium of microbes (patent pending) isolated at the Savannah River National Laboratory from a petroleum-contaminated site was added to the PRCS system. During operation, degradation of petroleum waste was accounted for through monitoring of carbon dioxide levels in the system effluent. The project demonstrated that co-contaminated soils could be successfully treated through bioventing and bioaugmentation to remove petroleum contamination to levels below 100 mg/kg while protecting workers and the environment from radiological contamination.

  3. Bioremediation of gasoline-contaminated soil using poultry litter

    SciTech Connect

    Gupta, G; Tao, J.

    1996-10-01

    Contaminated soil, excavated from around a leaking underground gasoline storage tank, is commonly subjected to thermal degradation to remove the gasoline. Bioremediation as an alternative treatment technology is now becoming popular. The important hydrocarbon-degrading bacteria include Pseudomonas, Arthrobacter, and Flavobacterium. Poultry litter contains a large number of microorganisms, including Pseudomonas, as well as many inorganic nutrients and organic biomass that may assist in biodegrading gasoline in contaminated soil. During bioremediation of contaminated soil, microbial densities are known to increase by 2-3 orders of magnitude. However, bioremediation may result in a increase in the toxic characteristics of the soil due to the production of potentially toxic degradation intermediates. The objective of this research was to study the influence of the addition of poultry litter on the bioremediation of gasoline-contaminated soil by quantifying the changes in the densities of microorganisms and by monitoring the toxicity of the degradation products. 25 refs., 5 figs., 2 tabs.

  4. Hydrocarbon status of soils under different ages of oil contamination

    NASA Astrophysics Data System (ADS)

    Gennadiev, A. N.; Pikovskii, Yu. I.; Kovach, R. G.; Koshovskii, T. S.; Khlynina, N. I.

    2016-05-01

    Modifications of the hydrocarbon status (HCS) of soils at the stages of the injection input of oil pollutants and the subsequent self-purification of the soil layer from technogenesis products have been revealed in studies conducted on an oil field. Comparison with the HCS of background soils has been performed. Changes in the composition and concentration of bitumoids, polycyclic aromatic hydrocarbons (PAHs), and hydrocarbon gases have been established. The HCS of a freshly contaminated soil is characterized by the predominance of butane (the highest component) in the gaseous phase, an abrupt increase in the concentration of second-kind bitumoids, and a 100-fold increase in the content of PAHs compared to the background soil. In the old contaminated soil, free and fixed methane becomes the predominant gas; the content of bitumoids in the upper soil horizons is lower than in the freshly contaminated soils by two orders of magnitude but higher than in the background soil by an order of magnitude; the PAH composition in the soil with old residual contamination remains slightly more diverse than in the background soil.

  5. Calculation of detection efficiency of the fiber-optic sensor to measure radioactive contamination using MCNP simulation

    NASA Astrophysics Data System (ADS)

    Joo, Hanyoung; Lee, Arim; Kim, Rinah; Park, Chan Hee; Moon, Joo Hyun

    2015-09-01

    In this paper, a fiber-optic radiation sensor (FORS) was developed to measure gamma rays from the radionuclides frequently found in radioactively contaminated soil. The sensing probe of the FORS was made of an inorganic (Lu,Y)2SiO5:Ce (LYSO:Ce) scintillator, a mixture of epoxy resin and hardener and a plastic fiber. The FORS was applied to measure gamma rays from Cs-137 source (1.1 μCi) in a disk shape. Also, MCNP simulation was performed for the same geometry as that in the experimental setup. Comparison between measurements by the FORS and MCNP simulation showed that the detection efficiency of the fiber-optic sensor was about 19.2%. The FORS is expected to be useful in measuring gamma rays from the radioactive soil at nuclear facility site.

  6. Bioremediation of leachate and soil contaminated with petroleum products

    SciTech Connect

    Yocum, P.S.

    1994-01-01

    Petroleum products are generally accepted to be biodegradable, whether they are contaminating a liquid or solid phase. Considerable reference material exist to support this ascertain. However, no parameters exist for design of engineered treatment systems and little is known about how mixed cultures degrade sparingly soluble substrates, particularly in the soil environment. Further the heterogeneity of contaminant distribution in the soil environment, inhibit understanding of the processes involved. This dissertation is an attempt to provide methodologies for the assessment of biodegradation of petroleum products in these environments, together with development of procedures applicable to assessment of remediation in soils with heterogenous distribution of contaminants.

  7. Activity of antibiotics in contaminated wounds containing clay soil.

    PubMed

    Roberts, A H; Rye, D G; Edgerton, M T; Rodeheaver, G T; Edlich, R F

    1979-03-01

    Most traumatic wounds are contaminated to some degree by soil and run a high risk of infection. The presence of soil in wounds interferes with natural tissue defenses, which include phagocytosis and serum bactericidal capacity. The experimental studies reported herein clearly demonstrate that soil also limits the antibacterial effects of specific antibiotics. This inactivation appears to be the result of a chemical reaction between the charged antibiotics and the soil particles. PMID:434335

  8. The existence state in the soil of radioactive cesium from the Fukushima Dai-ichi nuclear power plant accident by imaging plate photograph

    NASA Astrophysics Data System (ADS)

    Satou, Yukihiko; Sueki, Keisuke

    2013-04-01

    In the accident of the Fukushima Daiichi nuclear power plant, the wide area in east Japan was polluted seriously with radioactive cesium. But, unlike Chernobyl, reactor core explosion did not occur in Fukushima. Therefore, it is thought that many radioactive nuclides emitted into the atmosphere were in the gas state and aerosol. However, when the imaging plate photographs of the surface soils in Fukushima was observed, many granular radionuclides existed. Then, in order to confirm a radioactive cesium of particle state, the treatment for the soils contaminated with radioactive cesium by using chemical operation was tried. Three type soils, that is, paddy soil, river sediment, and sea sand, were made applicable to research. The contaminated soil samples were collected in Fukushima and Ibaraki prefecture. Radioactivity concentrations of 137Cs and 134Cs were measured by using gamma-ray spectrometry with a high pure germanium (HPGe) detector. After the radioactively measurement, soils had been burned in oven for five hours in 500 degree Celsius. Concentrated hydrochloric acid was added to soil samples, and they were heated for three hours. These samples were divided into residue and elution by centrifugal separation, and then radioactivity of cesium contained in residue was measured. After chemical operations, 70% and 85% of radioactive cesium from river sediment and sea sand were extracted approximately into elution, respectively. In contrast, in the soil of the paddy field, only 30% of radioactive cesium was approximately eluted. When radiation image photograph of the residues of all three types of soils were taken and observed, the granular radioactive nuclides remained clearly in paddy soil and river sediment. In contrast, all the granular radioactive nuclides in sea sand disappeared after treatment. The results of above things that desorption of radioactive cesium depend on the kind of soil. Furthermore, it was suggested that there was radioactive cesium of

  9. The tolerance efficiency of Panicum maximum and Helianthus annuus in TNT-contaminated soil and nZVI-contaminated soil.

    PubMed

    Jiamjitrpanich, Waraporn; Parkpian, Preeda; Polprasert, Chongrak; Laurent, François; Kosanlavit, Rachain

    2012-01-01

    This study was designed to compare the initial method for phytoremediation involving germination and transplantation. The study was also to determine the tolerance efficiency of Panicum maximum (Purple guinea grass) and Helianthus annuus (Sunflower) in TNT-contaminated soil and nZVI-contaminated soil. It was found that the transplantation of Panicum maximum and Helianthus annuus was more suitable than germination as the initiate method of nano-phytoremediation potting test. The study also showed that Panicum maximum was more tolerance than Helianthus annuus in TNT and nZVI-contaminated soil. Therefore, Panicum maximum in the transplantation method should be selected as a hyperaccumulated plant for nano-phytoremediation potting tests. Maximum tolerance dosage of Panicum maximum to TNT-concentration soil was 320 mg/kg and nZVI-contaminated soil was 1000 mg/kg in the transplantation method. PMID:22702809

  10. Soil Contamination and Remediation Strategies. Current research and future challenge

    NASA Astrophysics Data System (ADS)

    Petruzzelli, G.

    2012-04-01

    Soil contamination: the heritage of industrial development Contamination is only a part of a whole set of soil degradation processes, but it is one of paramount importance since soil pollution greatly influences the quality of water, food and human health. Soil contamination has been identified as an important issue for action in the European strategy for soil protection, it has been estimated that 3.5 million of sites are potentially contaminated in Europe. Contaminated soils have been essentially discovered in industrial sites landfills and energy production plants, but accumulation of heavy metals and organic compounds can be found also in agricultural land . Remediation strategies. from incineration to bioremediation The assessment of soil contamination is followed by remedial action. The remediation of contaminated soils started using consolidates technologies (incineration inertization etc.) previously employed in waste treatment,. This has contributed to consider a contaminated soil as an hazardous waste. This rough approximation was unfortunately transferred in many legislations and on this basis soil knowledge have been used only marginally in the clean up procedures. For many years soil quality has been identified by a value of concentration of a contaminant and excavation and landfill disposal of soil has been largely used. In the last years the knowledge of remediation technology has rapidly grown, at present many treatment processes appear to be really feasible at field scale, and soil remediation is now based on risk assessment procedures. Innovative technologies, largely dependent on soil properties, such as in situ chemical oxidation, electroremediation, bioventing, soil vapor extraction etc. have been successfully applied. Hazardous organic compounds are commonly treated by biological technologies, biorememdiation and phytoremediation, being the last partially applied also for metals. Technologies selection is no longer exclusively based on

  11. Bioremediation of lead contaminated soil with Rhodobacter sphaeroides.

    PubMed

    Li, Xiaomin; Peng, Weihua; Jia, Yingying; Lu, Lin; Fan, Wenhong

    2016-08-01

    Bioremediation with microorganisms is a promising technique for heavy metal contaminated soil. Rhodobacter sphaeroides was previously isolated from oil field injection water and used for bioremediation of lead (Pb) contaminated soil in the present study. Based on the investigation of the optimum culturing conditions and the tolerance to Pb, we employed the microorganism for the remediation of Pb contaminated soil simulated at different contamination levels. It was found that the optimum temperature, pH, and inoculum size for R. sphaeroides is 30-35 °C, 7, and 2 × 10(8) mL(-1), respectively. Rhodobacter sphaeroides did not remove the Pb from soil but did change its speciation. During the bioremediation process, more available fractions were transformed to less accessible and inert fractions; in particular, the exchangeable phase was dramatically decreased while the residual phase was substantially increased. A wheat seedling growing experiment showed that Pb phytoavailability was reduced in amended soils. Results inferred that the main mechanism by which R. sphaeroides treats Pb contaminated soil is the precipitation formation of inert compounds, including lead sulfate and lead sulfide. Although the Pb bioremediation efficiency on wheat was not very high (14.78% root and 24.01% in leaf), R. sphaeroides remains a promising alternative for Pb remediation in contaminated soil. PMID:27179240

  12. Kinetics of Cd Release from Some Contaminated Calcareous Soils

    SciTech Connect

    Sajadi Tabar, S.; Jalali, M.

    2013-03-15

    Contamination of soils with heavy metals may pose long-term risk to groundwater quality leading to health implications. Bioavailability of heavy metals, like cadmium (Cd) is strongly affected by sorption and desorption processes. The release of heavy metals from contaminated soils is a major contamination risks to natural waters. The release of Cd from contaminated soils is strongly influenced by its mobility and bioavailability. In this study, the kinetics of Cd desorption from ten samples of contaminated calcareous soils, with widely varying physicochemical properties, were studied using 0.01 M EDTA extraction. The median percentage of Cd released was about 27.7% of the total extractable Cd in the soils. The release of Cd was characterized by an initial fast release rate (of labile fractions) followed by a slower release rate (of less labile fractions) and a model of two first-order reactions adequately describes the observed release of Cd from the studied soil samples. There was positive correlation between the amount of Cd released at first phase of release and Cd in exchangeable fraction, indicating that this fraction of Cd is the main fraction controlling the Cd in the kinetic experiments. There was strongly negative correlation between the amount of Cd released at first and second phases of release and residual fraction, suggesting that this fraction did not contribute in Cd release in the kinetic experiments. The results can be used to provide information for evaluation of Cd potential toxicity and ecological risk from contaminated calcareous soils.

  13. Humus-assisted cleaning of heavy metal contaminated soils

    NASA Astrophysics Data System (ADS)

    Borggaard, Ole K.; Rasmussen, Signe B.

    2016-04-01

    Contamination of soils with non-degradable heavy metals (HMs) because of human acticities is globally a serious problem threatening human health and ecosystem functioning. To avoid negative effects, HMs must be removed either on-site by plant uptake (phytoremediation) or off-site by extraction (soil washing). In both strategies, HM solubility must be augmented by means of a strong ligand (complexant). Often polycarboxylates such as EDTA and NTA are used but these ligands are toxic, synthetic (non-natural) and may promote HM leaching. Instead naturally occurring soluble humic substances (HS) were tested as means for cleaning HM contaminated soils; HS samples from beech and spruce litter, compost percolate and processed cow slurry were tested. Various long-term HM contaminated soils were extracted with solutions of EDTA, NTA or HS at different pH by single-step and multiple-step extraction mode. The results showed that each of the three complexant types increased HM solubility but the pH-dependent HM extraction efficiency decreased in the order: EDTA ≈ NTA > HS. However, the naturally occurring HS seems suitable for cleaning As, Cd, Cu and Zn contaminated soils both in relation to phytoremediation of moderately contaminated soils and washing of strongly contaminated soils. On the other hand, HS was found unsuited as cleaning agent for Pb polluted calcareous soils. If future field experiments confirm these laboratory results, we have a new cheap and environmentally friendly method for solving a great pollution problem, i.e. cleaning of heavy metal contaminated soils. In addition, humic substances possess additional benefits such as improving soil structure and stimulating microbial activity.

  14. As Leaching into Fresh Water from Highly Contaminated Hawaiian Soils

    NASA Astrophysics Data System (ADS)

    Niklis, N. J.; Rubin, K. H.; El-Kadi, A. I.

    2009-12-01

    Arsenic contamination of current and former agricultural soils in Hawaii is an unfortunate legacy of plantation era agricultural practices. Here, we report an investigation of As mobility in fresh water from highly contaminated (0.8 % As) A-zone Hawaiian andisols from the Hamakua Coast of the Island of Hawai’i. Aliquots of the same acidic soil (pH= 5.0) were exposed to fresh water for varying lengths of time and analyzed to quantify the fraction of As and other elements leached from the soil relative to concentrations determined by total digestion. A maximum of 0.04% of As and 0.05% of Fe were removed from the soils in initial rinses and multi-day leaches using 18 megaohm Millipore water, in experiments lasting up to 35 days. Arsenic concentrations were highest in initial soil rinses, indicating that a small fraction of the total As in the soil is either loosely bound or present as a fine-grained, soluble As-bearing phase. During subsequent leaching experiments, arsenic and most other inorganic ions that we analyzed for reached equilibrium after 3 days; Fe reached equilibrium concentrations after 10 days. All soil solutions contained As levels that exceeded the EPA acceptable drinking water limit of 0.01 ppm. However, contaminant transport modeling suggests that As contaminated leachates would not migrate substantially from this site, so that local isolation and storage of contaminated soils would likely be an acceptable containment method.

  15. Sorption of radioactive contaminants by sediment from the Kara Sea

    SciTech Connect

    Fuhrmann, M.; Zhou, H.; Neiheisel, J.; Dyer, R.

    1995-02-01

    The purpose of this study is to quantify some of the parameters needed to perform near-field modeling of sites in the Kara Sea that were impacted by the disposal of radioactive waste. The parameters of interest are: the distribution coefficients (K{sub d}) for several important radionuclides, the mineralogy of the sediment, and the relationship of K{sub d} to liquid to solid ratio. Sediment from the Kara Sea (location: 73{degrees} 00` N, 58{degrees} 00` E) was sampled from a depth of 287 meters on August 23/24, 1992, during a joint Russian/Norwegian scientific cruise. Analysis of the material included mineralogy, grain size and total organic carbon. Uptake kinetics were determined for {sup 85}Sr, {sup 99}Tc, {sup 125}I, {sup 137}Cs, {sup 210}Pb, {sup 232}U, and {sup 241}Am and distribution coefficients (K{sub d}) were determined for these radionuclides using batch type experiments. Sorption isotherms were developed for {sup 85}Sr, {sup 99}Tc, and {sup 137}Cs to examine the effect that varying the concentration of a tracer has on the quantity of that tracer taken up by the solid. The effect of liquid to solid ratio on the uptake of contaminants was determined for {sup 99}Tc and {sup 137}Cs. In another set of experiments, the sediment was separated into four size fractions and uptake was determined for each fraction for {sup 85}Sr, {sup 99}Tc, and {sup 137}Cs. In addition, the sediment was analyzed to determine if it contains observable concentrations of anthropogenic radionuclides.

  16. X-231B technology demonstration for in situ treatment of contaminated soil: Contaminant characterization and three dimensional spatial modeling

    SciTech Connect

    West, O.R.; Siegrist, R.L.; Mitchell, T.J.; Pickering, D.A.; Muhr, C.A.; Greene, D.W.; Jenkins, R.A.

    1993-11-01

    Fine-textured soils and sediments contaminated by trichloroethylene (TCE) and other chlorinated organics present a serious environmental restoration challenge at US Department of Energy (DOE) sites. DOE and Martin Marietta Energy Systems, Inc. initiated a research and demonstration project at Oak Ridge National Laboratory. The goal of the project was to demonstrate a process for closure and environmental restoration of the X-231B Solid Waste Management Unit at the DOE Portsmouth Gaseous Diffusion Plant. The X-231B Unit was used from 1976 to 1983 as a land disposal site for waste oils and solvents. Silt and clay deposits beneath the unit were contaminated with volatile organic compounds and low levels of radioactive substances. The shallow groundwater was also contaminated, and some contaminants were at levels well above drinking water standards. This document begins with a summary of the subsurface physical and contaminant characteristics obtained from investigative studies conducted at the X-231B Unit prior to January 1992 (Sect. 2). This is then followed by a description of the sample collection and analysis methods used during the baseline sampling conducted in January 1992 (Sect. 3). The results of this sampling event were used to develop spatial models for VOC contaminant distribution within the X-231B Unit.

  17. IN-SITU TREATMENT OF HAZARDOUS WASTE CONTAMINATED SOILS

    EPA Science Inventory

    Techniques were investigated for in-situ treatment of hazardous wastes that could be applied to contaminated soils. Included were chemical treatment methods, biological treatment, photochemical transformations and combination methods. Techniques were developed based on fundamenta...

  18. Radioactivities vs. depth in Apollo 16 and 17 soil

    NASA Technical Reports Server (NTRS)

    Fireman, E. L.; D'Amico, J.; Defelice, J.

    1973-01-01

    The radioactivities of Ar-37, Ar-39, and H-3 measured at a number of depths for Apollo 16 and 17 soil are reported. The Ar-37 activities vs depth in the Apollo 16 drill string increased with depth and reached a broad maximum in the neighborhood of 50 g per sq cm before decreasing. The Ar-39 activities in Apollo 17 soil were higher than in Apollo 16 soil, probably owing to the higher Fe and Ti contents. The H-3 activities in Apollo 16 and 17 soil were quite similar and indicate that the 4 August 1972 flare produced very little H-3 compared to the amount produced by solar flares during the previous 50 years.

  19. Assessing soil and groundwater contamination in a metropolitan redevelopment project.

    PubMed

    Yun, Junki; Lee, Ju Young; Khim, Jeehyeong; Ji, Won Hyun

    2013-08-01

    The purpose of this study was to assess contaminated soil and groundwater for the urban redevelopment of a rapid transit railway and a new mega-shopping area. Contaminated soil and groundwater may interfere with the progress of this project, and residents and shoppers may be exposed to human health risks. The study area has been remediated after application of first remediation technologies. Of the entire area, several sites were still contaminated by waste materials and petroleum. For zinc (Zn) contamination, high Zn concentrations were detected because waste materials were disposed in the entire area. For petroleum contamination, high total petroleum hydrocarbon (TPH) and hydrocarbon degrading microbe concentrations were observed at the depth of 7 m because the underground petroleum storage tank had previously been located at this site. Correlation results suggest that TPH (soil) concentration is still related with TPH (groundwater) concentration. The relationship is taken into account in the Spearman coefficient (α). PMID:23307052

  20. Decreasing the contamination and toxicity of a heavily contaminated soil by in situ bioremediation

    NASA Astrophysics Data System (ADS)

    Groudev, Stoyan; Georgiev, Plamen; Spasova, Irena; Nikolova, Marina

    2013-04-01

    An experimental plot of 140 m2 consisting of acidic soil heavily contaminated with uranium, non-ferrous metals (mainly Cu, Zn and Cd) and arsenic was treated in situ under real field conditions using the activity of the indigenous soil microflora. This activity was enhanced by suitable changes of some essential environmental factors such as pH and water, oxygen and nutrient contents of the soil. The treatment was connected with solubilization and removal of contaminants from the top soil layers (horizon A) due to the joint action of the soil microorganisms (mainly acidophilic chemolithotrophic bacteria) and leach solutions (diluted sulphuric acid). The dissolved contaminants were transferred to the soil horizon B and were removed from the soil profile through a system of drainage collecting pipes. The contaminated soil effluents were treated by means of a multi-component passive system consisting of an anoxic alkalizing drain, a permeable reactive multibarrier and a rock filter. The contamination and toxicity of the soil were regularly tested during the cleaning procedure and were considerably decreased at the end of the treatment.

  1. Toxicity assessment of contaminated soils from an antitank firing range.

    PubMed

    Robidoux, Pierre Yves; Gong, Ping; Sarrazin, Manon; Bardai, Ghalib; Paquet, Louise; Hawari, Jalal; Dubois, Charles; Sunahara, Geoffrey I

    2004-07-01

    Explosives are released into the environment at production and processing facilities, as well as through field use. These compounds may be toxic at relatively low concentrations to a number of ecological receptors. A toxicity assessment was carried out on soils from an explosive-contaminated site at a Canadian Forces Area Training Center. Toxicity studies on soil organisms using endpoints such as microbial processes (potential nitrification activity, dehydrogenase activity, substrate-induced respiration, basal respiration), plant seedling and growth (Lactuca sativa and Hordeum vulgare), and earthworm (Eisenia andrei) growth and reproduction were carried out. Results showed that 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane (HMX) was the principal polynitro-organic compound measured in soils. Soils from the contaminated site decreased microbial processes and earthworm reproduction; whereas plant growth was not significantly reduced. Toxicity to aquatic organisms and genotoxicity were also assessed on soil elutriates using Microtox (Vibrio fischeri), growth inhibition of algae (Selenastrum capricornutum), and SOS Chromotest (Escherichia coli). Results indicated that soil elutriates were generally not toxic to bacteria (Microtox) and algae. However, genotoxicity was found in a number of soil elutriate samples. Thus, the explosive-contaminated soils from the antitank firing range may represent a hazard for the soil organisms. Nevertheless, the global toxicity might have partially resulted from HMX as well as from other (not identified) contaminants such as heavy metals. PMID:15223256

  2. Microbial ecology and transformations associated with munitions contaminated soils

    SciTech Connect

    Martin, J.L.; Li, Z.; Kokjohn, T.A.; Shea, P.J.; Comfort, S.D.

    1994-12-31

    Many acres of soil at the former Nebraska Ordnance Plant (NOP) are contaminated with TNT and other munitions residues. In some areas, solid phase TNT is present and controls the concentration of the soil solution. Native microbial populations in uncontaminated soils similar to those at the NOP site were severely reduced when solid phase TNT was allowed to control the soil solution TNT concentration. However, examination of NOP soil revealed an active population of Pseudomonas sp. A single species that could utilize TNT as a sole C source was isolated from the contaminated soil and tentatively identified as Pseudomonas corrugata through the BIOLOG system. Subsequent growth and characterization experiments indicate that the Pseudomonad metabolizes TNT while in the exponential phase of growth in medium containing glucose as a sole N source. Low TNT mineralization rates (measured by CO{sub 2} evolution) in soil and media using the various isolates suggest reduced availability due to sorption and incorporation of transformation intermediates into the organic matrix and microbial biomass. Pretreatment of TNT by acid-metal catalyzed reduction resulted in an initially higher rate of mineralization following addition to TNT-contaminated soil. Observations indicate more rapid microbial utilization of the 2,4,6-triaminotoluene (TAT) reduction product and its spontaneous decay product, methylphloroglucinol (2,4,6-trihydroxytoluene), than TNT. Abiotic pretreatment may be useful in enhancing microbial transformation and detoxification of TNT in highly contaminated soils.

  3. Selective leaching of uranium from uranium-contaminated soils

    SciTech Connect

    Francis, C.W.; Mattus, A.J.; Farr, L.L.; Lee, S.Y.; Elless, M.P. |

    1993-06-01

    Three soils and a sediment contaminated with uranium were used to determine the effectiveness of sodium carbonate and citric acid leaching to decontaminate or remove uranium to acceptable regulatory levels. The objective was to selectively extract uranium using a soil washing/extraction process without seriously degrading the soil`s physicochemical characteristics or generating a secondary waste form that would be difficult to manage and/or dispose of. Two of the soils were surface soils from the DOE facility formerly called the Feed Materials Production Center (FMPC) at Fernald, Ohio. One of the soils is from near the Plant 1 storage pad and the other soil was taken from near a waste incinerator used to burn low-level contaminated trash. The third soil was a surface soil from an area formally used as a landfarm for the treatment of spent oils at the Oak Ridge Y-12 Plant. The sediment sample was material sampled from a storm sewer sediment trap at the Oak Ridge Y-12 Plant. Uranium concentrations in the Fernald soils ranged from 450 to 550 {mu}g U/g of soil while the samples from the Y-12 Plant ranged from 150 to 200 {mu}g U/g of soil.

  4. In Situ Formation of Calcium Apatite in Soil for Sequestering Contaminants in Soil and Groundwater

    SciTech Connect

    Moore, Robert; Szecsody, Jim; Thompson, Mike

    2015-10-20

    A new method for in situ formation of a calcium apatite permeable reactive barrier that is a groundbreaking technology for containing radioactive/heavy metal contaminants threatening groundwater supplies.

  5. Reconstruction of (131)I radioactive contamination in Ukraine caused by the Chernobyl accident using atmospheric transport modelling.

    PubMed

    Talerko, Nikolai

    2005-01-01

    The evaluation of (131)I air and ground contamination field formation in the territory of Ukraine was made using the model of atmospheric transport LEDI (Lagrangian-Eulerian DIffusion model). The (131)I atmospheric transport over the territory of Ukraine was simulated during the first 12 days after the accident (from 26 April to 7 May 1986) using real aerological information and rain measurement network data. The airborne (131)I concentration and ground deposition fields were calculated as the database for subsequent thyroid dose reconstruction for inhabitants of radioactive contaminated regions. The small-scale deposition field variability is assessed using data of (137)Cs detailed measurements in the territory of Ukraine. The obtained results are compared with available data of radioiodine daily deposition measurements made at the network of meteorological stations in Ukraine and data of the assessments of (131)I soil contamination obtained from the (129)I measurements. PMID:16024139

  6. Remediation of arsenic-contaminated soils and groundwaters

    DOEpatents

    Peters, Robert W.; Frank, James R.; Feng, Xiandong

    1998-01-01

    An in situ method for extraction of arsenic contaminants from a soil medium and remediation of the medium including contacting the medium with an extractant solution, directing the solution within and through the medium, and collecting the solution and contaminants. The method can also be used for arsenate and/or arsenite removal.

  7. Remediation of arsenic-contaminated soils and groundwaters

    DOEpatents

    Peters, R.W.; Frank, J.R.; Feng, X.

    1998-06-23

    An in situ method is described for extraction of arsenic contaminants from a soil medium and remediation of the medium including contacting the medium with an extractant solution, directing the solution within and through the medium, and collecting the solution and contaminants. The method can also be used for arsenate and/or arsenite removal. 8 figs.

  8. Phytoremediation Potential of Lead-Contaminated Soil Using Tropical Grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The global problem concerning contamination of the environment because of human activities is increasing. Most of the environmental contaminants are chemical by-products and heavy metals such as lead (Pb). Lead released into the environment makes its way into the air, soil and water. Lead contribute...

  9. Electroosmotic flow behaviour of metal contaminated expansive soil.

    PubMed

    Sivapullaiah, P V; Prakash, B S Nagendra

    2007-05-17

    It is important to study the flow behaviour through soil during electrokinetic extraction of contaminants to understand their removal mechanism. The flow through the expansive soil containing montmorillonite is monitored during laboratory electrokinetic extraction of heavy metal contaminants. The permeability of soil, which increases due to the presence of contaminants, is further enhanced during electrokinetic extraction of contaminants due to osmotic permeability. The variations in flow rates through the soil while the extracting fluid is changed to dilute acetic acid (used to control the increase of pH) and EDTA solution (used to desorb the metal ions from soil) are studied. The trends of removal of contaminants vis-a-vis the changes in the flow through the soil during different phases of electrokinetic extraction are established. Chromium ions are removed by flushing of water through the soil and increased osmotic flow is beneficial. Removal of iron ions is enhanced by induced osmotic flow and desorption of ions by electrokinetic processes. PMID:17276001

  10. Vertical column hydroclassification of metal-contaminated soils.

    PubMed

    Williford, C W; Li, Z; Wang, Z; Bricka, R M

    1999-04-23

    The purpose of this work was to reduce soil volumes requiring aggressive treatment. A second purpose was to determine differences in separation due to distinct forms of the metal contamination and soil texture. The objectives were to apply hydroclassification and find mass and metal-contaminant distribution of four soils contaminated with heavy metals from firing ranges, a small arms incinerator, and an electroplating operation. The soils were slurried in water, sieved, and exposed to upward flowing water to separate the soil particles into four nominal size ranges. The popping furnace soil exhibited substantial lead among all particle size fractions. The firing range soils exhibited bimodal distributions. The electroplating soil exhibited a strong concentration of metals toward the <63 microm fraction. Attrition scrubbing moderately improved the enrichment of metals in several fractions. Extraction revealed the lead and chromium in the electroplating soil to be relatively immobile. These results suggest metal distributions are influenced by the different mechanisms of introduction into the soil. They also help to predict performance of processing options such as sieving hydroclassification and attrition scrubbing. PMID:10379028

  11. Feasibility Process for Remediation of the Crude Oil Contaminated Soil

    NASA Astrophysics Data System (ADS)

    Keum, H.; Choi, H.; Heo, H.; Lee, S.; Kang, G.

    2015-12-01

    More than 600 oil wells were destroyed in Kuwait by Iraqi in 1991. During the war, over 300 oil lakes with depth of up to 2m at more than 500 different locations which has been over 49km2. Therefore, approximately 22 million m3was crude oil contaminated. As exposure of more than 20 years under atmospheric conditions of Kuwait, the crude oil has volatile hydrocarbons and covered heavy oily sludge under the crude oil lake. One of crude oil contaminated soil which located Burgan Oilfield area was collected by Kuwait Oil Company and got by H-plus Company. This contaminated soil has about 42% crude oil and could not biodegraded itself due to the extremely high toxicity. This contaminated soil was separated by 2mm sieve for removal oil sludge ball. Total petroleum hydrocarbons (TPH) was analysis by GC FID and initial TPH concentration was average 48,783 mg/kg. Ten grams of the contaminated soil replaced in two micro reactors with 20mL of bio surfactant produce microorganism. Reactor 1 was added 0.1g powder hemoglobin and other reactor was not added hemoglobin at time 0 day. Those reactors shake 120 rpm on the shaker for 7 days and CO2 produced about 150mg/L per day. After 7 days under the slurry systems, the rest days operated by hemoglobin as primary carbon source for enhanced biodegradation. The crude oil contaminated soil was degraded from 48,783mg/kg to 20,234mg/kg by slurry process and final TPH concentration degraded 11,324mg/kg for 21days. Therefore, highly contaminated soil by crude oil will be combined bio slurry process and biodegradation process with hemoglobin as bio catalytic source. Keywords: crude-oil contaminated soil, bio slurry, biodegradation, hemoglobin ACKOWLEDGEMENTS This project was supported by the Korea Ministry of Environment (MOE) GAIA Program

  12. ACID EXTRACTION TREATMENT SYSTEM FOR TREATMENT OF METAL CONTAMINATED SOILS

    EPA Science Inventory

    The Acid Extraction Treatment System (AETS) reduces the concentrations and/or leachability of heavy metals in contaminated soils so the soil can be returned to the site from which it originated. he objective of the project was to determine the effectiveness and commercial viabili...

  13. Toxicity testing of trinitrotoluene-contaminated soil composts

    SciTech Connect

    Honeycutt, M.E.; McFarland, V.A.; Jarvis, A.S.

    1997-10-01

    The Mutatox{trademark} assay and earthworm acute toxicity test were employed to evaluate the efficacy of composting in reducing the toxicity of TNT-contaminated soils. The Mutatox assay is a proprietary bacterial bioluminescence test that determines the mutagenic potential of sample extracts. The earthworm acute toxicity test was chosen because it exposes the organisms to the unaltered contaminant/solid matrix. Rockeye soil, a TNT-contaminated soil collected from a military installation, was composted using two methods. This yielded five samples, Rockeye, Compost A composting. Soil extracts were prepared for Mutatox using the sonification method. Ten serial dilution samples were tested soils/artificial soil were tested in the earthworm toxicity test. In the Rockeye soil samples, a toxic response was shown in both test methods. Mutatox indicated no toxicity in Composts A and B after composting but did not show a positive mutagenic response in the lower serial dilutions. The LC50s for Compost A and B after composting in the earthworm toxicity test were 35.3% and 100%, respectively. Using Mutatox and the earthworm toxicity test together provides a sensitive means of monitoring the effectiveness of various composting techniques for remediating TNT-contaminated soils.

  14. ENGINEERING ISSUE: IN SITU BIOREMEDIATION OF CONTAMINATED UNSATURATED SUBSURFACE SOILS

    EPA Science Inventory

    An emerging technology for the remediation of unsaturated subsurface soils involves the use of microorganisms to degrade contaminants which are present in such soils. Understanding the processes which drive in situ bioremediation, as well as the effectiveness and efficiency of th...

  15. Ethanol-enhanced bioremediation of PAH-contaminated soils

    SciTech Connect

    Lee, P.H.; Ong, S.K.; Golchin, J.

    1999-07-01

    Bioremediation of soils contaminated with polycyclic aromatic hydrocarbons (PAHs) is highly challenging because of the low solubility and strong sorption properties of PAHs to soil organic matter. Two PAH-contaminated soils from former manufactured gas plant (MGP) sites were pretreated with ethanol to enhance the bioavailability of PAH compounds. The biodegradation of various PAHs in the pretreated soils was assessed using soil slurry reactor studies. The time needed to degrade 90% of the total PAH in the pretreated soils was at least 5 days faster than soils that were not pretreated with ethanol. A distinctive advantage with the pretreatment of soils with ethanol was the enhanced removal of 4-ring compounds such as chrysene. Approximately 90% of chrysene in the ethanol-treated soils were removed within 15 days while soils without pretreatment needed more than 30 days to obtain similar removal levels. After 35 days of biotreatment in the slurry reactors, approximately 40% of benzo(a)pyrene were removed in the ethanol-treated soils while only 20% were removed in soils not pretreated with ethanol.

  16. Toxicity tests of soil contaminated by recycling of scrap plastics

    SciTech Connect

    Wong, M.H.; Chui, V.W. )

    1990-03-01

    The present investigation studied the toxicity of soil contaminated by untreated discharge from a factory that recycles used plastics. The nearby agricultural areas and freshwater fish ponds were polluted with high concentrations of Cu, Ni, and Mn. Water extracts from the contaminated soil retarded root growth of Brassica chinensis (Chinese white cabbage) and Cynodon dactylon (Bermuda grass) where their seeds were obtained commercially. The contaminated populations of C. dactylon, Panicum repen (panic grass), and Imperata cylindrica (wooly grass) were able to withstand higher concentrations of Cu, Ni, and Mn, especially C. dactylon, when compared with their uncontaminated counterparts.

  17. Laboratory scale vitrification of low-level radioactive nitrate salts and soils from the Idaho National Engineering Laboratory

    SciTech Connect

    Shaw, P.; Anderson, B.; Davis, D.

    1993-07-01

    INEL has radiologically contaminated nitrate salt and soil waste stored above and below ground in Pad A and the Acid Pit at the Radioactive Waste Management Complex. Pad A contain uranium and transuranic contaminated potassium and sodium nitrate salts generated from dewatered waste solutions at the Rocky Flats Plant. The Acid Pit was used to dispose of liquids containing waste mineral acids, uranium, nitrate, chlorinated solvents, and some mercury. Ex situ vitrification is a high temperature destruction of nitrates and organics and immobilizes hazardous and radioactive metals. Laboratory scale melting of actual radionuclides containing INEL Pad A nitrate salts and Acid Pit soils was performed. The salt/soil/additive ratios were varied to determine the range of glass compositions (resulted from melting different wastes); maximize mass and volume reduction, durability, and immobilization of hazardous and radioactive metals; and minimize viscosity and offgas generation for wastes prevalent at INEL and other DOE sites. Some mixtures were spiked with additional hazardous and radioactive metals. Representative glasses were leach tested and showed none. Samples spiked with transuranic showed low nuclide leaching. Wasteforms were two to three times bulk densities of the salt and soil. Thermally co-processing soils and salts is an effective remediation method for destroying nitrate salts while stabilizing the radiological and hazardous metals they contain. The measured durability of these low-level waste glasses approached those of high-level waste glasses. Lab scale vitrification of actual INEL contaminated salts and soils was performed at General Atomics Laboratory as part of the INEL Waste Technology Development and Environmental Restoration within the Buried Waste Integrated Demonstration Program.

  18. ENGINEERING BULLETIN: SEPARATION/CONCENTRATION TECHNOLOGY ALTERNATIVES FOR THE REMEDIATION OF PESTICIDE-CONTAMINATED SOIL

    EPA Science Inventory

    Pesticide contamination includes a wide variety of compounds and may result from manufacturing improper storage, handling, disposal; or agricultural processes. It can occur in soil and can lead to secondary contamination of groundwater. Remediation of pesticide-contaminated soils...

  19. In situ vitrification: Providing a comprehensive solution for remediation of contaminated soils

    SciTech Connect

    Tixier, J.S.; Thompson, L.E.

    1993-09-01

    In situ vitrification is a thermal treatment technology being developed for remediation of contaminated soils. The process transforms easily leached, contaminated soils into a leach-resistant, vitreous and crystalline monolith. The process is applicable to a wide range of soil types and conditions that include virtually any combination of radioactive, hazardous, and mixed waste contaminants. The process is currently applicable to sites that are less than 5-m deep and that do not contain sealed containers. The range of capabilities and limitations of the process is discussed in the paper. Also discussed are the results of two recent demonstrations, one a pilot-scale test on a model radioactive site at Oak Ridge, TN, the other a full-scale test on a mixed waste disposal crib at Hanford, WA. These and other successful tests have led to preparation for three near-term future demonstrations at these sites; a discussion of the plans and expectations for the demonstrations is also included in the paper.

  20. The remediation of lead contaminated soils using solvent extraction chelation techniques. Final report

    SciTech Connect

    Price, M.; Hanson, A.T.; Rudd, B.; Pickins, D.; Krause, K.

    1998-08-01

    This report describes preliminary work leading to the development of an innovative technology for treating a mixed waste problem at Los Alamos National Laboratory (LANL). The specific problem being addressed by this research is the result of research activity at the Meson Physics Facility (LAMPH). The LAMPH facility conducts high energy neutron research. Lead BB`s were placed in containers and used as shielding during experiments.This lead was stored in piles on the ground when it was not in use, and it sometimes sat for extended periods of time, perhaps as long as 20 years. The lead was mobilized overtime, and contaminated the underlying soil. Because of the neutron bombardment, a portion of the lead {sup 207}Pb became radioactive {sup 210}Pb, and the lead became both a listed waste and radioactive, which classified it as a mixed waste. The contaminated soil has been removed from the site and placed in drums for storage until a suitable treatment technology can be identified. The contents of the barrels consists of a mixture of lead contaminated soil and lead BB`s.

  1. Bioremediation Techniques of Oil Contaminated Soils in Ohio

    SciTech Connect

    Hodges, David

    1996-10-03

    The objective of this project is to develop environmentally sound and cost-effective remediation techniques for crude oil contaminated soils. By providing a guidance manual to oil and gas operators, the Ohio Division of Oil and Gas regulatory authority hopes to reduce remediation costs while improving voluntary compliance with soil clean-up requirements. This shall be accomplished by conducting a series of field tests to define the optimum range for nutrient and organic enhancement to biologically remediate soils contaminated with brines and crude oil having a wide rage of viscosity.

  2. Bioremediation potential of diesel-contaminated Libyan soil.

    PubMed

    Koshlaf, Eman; Shahsavari, Esmaeil; Aburto-Medina, Arturo; Taha, Mohamed; Haleyur, Nagalakshmi; Makadia, Tanvi H; Morrison, Paul D; Ball, Andrew S

    2016-11-01

    Bioremediation is a broadly applied environmentally friendly and economical treatment for the clean-up of sites contaminated by petroleum hydrocarbons. However, the application of this technology to contaminated soil in Libya has not been fully exploited. In this study, the efficacy of different bioremediation processes (necrophytoremediation using pea straw, bioaugmentation and a combination of both treatments) together with natural attenuation were assessed in diesel contaminated Libyan soils. The addition of pea straw was found to be the best bioremediation treatment for cleaning up diesel contaminated Libyan soil after 12 weeks. The greatest TPH degradation, 96.1% (18,239.6mgkg(-1)) and 95% (17,991.14mgkg(-1)) were obtained when the soil was amended with pea straw alone and in combination with a hydrocarbonoclastic consortium respectively. In contrast, natural attenuation resulted in a significantly lower TPH reduction of 76% (14,444.5mgkg(-1)). The presence of pea straw also led to a significant increased recovery of hydrocarbon degraders; 5.7log CFU g(-1) dry soil, compared to 4.4log CFUg(-1) dry soil for the untreated (natural attenuation) soil. DGGE and Illumina 16S metagenomic analyses confirm shifts in bacterial communities compared with original soil after 12 weeks incubation. In addition, metagenomic analysis showed that original soil contained hydrocarbon degraders (e.g. Pseudoxanthomonas spp. and Alcanivorax spp.). However, they require a biostimulant (in this case pea straw) to become active. This study is the first to report successful oil bioremediation with pea straw in Libya. It demonstrates the effectiveness of pea straw in enhancing bioremediation of the diesel-contaminated Libyan soil. PMID:27479774

  3. Temperature effects on propylene glycol-contaminated soil cores

    SciTech Connect

    Davis-Hoover, W.J.; Vesper, S.J.

    1995-12-31

    The authors are examining the effect of temperature on the biodegradation of propylene glycol (PPG) in subsurface soil cores. Subsurface soils were contaminated in situ with PPG and allowed to diffuse into the soil for 30 days. The treated soil was reexposed, and intact were incubated for 30 days at temperatures ranging from 9 to 39 C in a temperature gradient incubator. At 30 days, soil moisture, soil pH, microbial activity [fluorescein diacetate (FDA) test], R2A plate counts, and plate counts of PPG degraders were studied. Although the soil moisture and pH remained relatively unchanged, the parameters of microbial activity varied rather consistently with temperature. Multiple populations or subpopulations of bacteria appear to exist between temperatures of 9 and 39 C in these soils.

  4. Bioremediation of an oil-contaminated soil by fungal intervention

    SciTech Connect

    McGugan, B.R.; Lees, Z.M.; Senior, E.

    1995-12-31

    The central aim of this study was to determine if indigenous fungal species present in an oil-contaminated soil are capable of bioremediating the contamination. Some of the contamination has been present at a disused oil-recycling plant site for over two decades, and it was felt that the indigenous microbial species should have been subjected to specific selection pressure for a protracted period, thus effecting key enzymatic capabilities for degradation in situ. Two experimental approaches to a landfarming type or remediation were examined. The first involved a simple biostimulation process of soil fungi. The second incorporated an extensive isolation and screening program with subsequent bulking and reinoculation into the contaminated soil.

  5. Chemical oxidation of hexachlorocyclohexanes (HCHs) in contaminated soils.

    PubMed

    Usman, M; Tascone, O; Faure, P; Hanna, K

    2014-04-01

    Chemical oxidation of hexachlorocyclohexanes (HCHs) was evaluated in (i) artificially spiked sand with HCH isomers (α, β, γ and δ) and (ii) contaminated soil sampled from a former gravel pit backfilled with wastes of lindane (γ-HCH). Following oxidation treatments were employed: hydrogen peroxide alone (HP), hydrogen peroxide with soluble Fe(II) (Fenton-F), sodium persulfate alone (PS), Fe(II) activated persulfate (AP) and permanganate (PM). GC-MS results revealed a significant degradation of all isomers in spiked soil in the order: F>PS>AP>HP>PM. Soluble Fe(II) enhanced the efficiency of H2O2 but decreased the reactivity of persulfate. Similar trend was observed in contaminated soil, but with less degradation probably caused by scavenging effect of organic matter and soil minerals and/or pollutant unavailability. No significant increase in oxidation efficiency was observed after using availability-enhancement agents in contaminated soil. Other limitation factors (oxidant dose, pH, catalyst type etc.) were also addressed. Among all the isomers tested, β-HCH was the most recalcitrant one which could be explained by higher metabolic and chemical stability. No by-products were observed by GC-MS regardless of the oxidant used. For being the premier study reporting chemical oxidation of HCH isomers in contaminated soils, it will serve as a base for in-situ treatments of sites contaminated by HCH isomers and other persistent organic pollutants. PMID:24486498

  6. Effect of biodegradable amendments on uranium solubility in contaminated soils.

    PubMed

    Duquène, L; Tack, F; Meers, E; Baeten, J; Wannijn, J; Vandenhove, H

    2008-02-25

    Chelate-assisted phytoextraction has been proposed as a potential tool for phytoremediation of U contaminated sites. In this context, the effects of five biodegradable amendments on U release in contaminated soils were evaluated. Three soils were involved in this study, one with a relatively high background level of U, and two which were contaminated with U from industrial effluents. Soils were treated with 5 mmol kg(-1) dry weight of either citric acid, NH(4)-citrate/citric acid, oxalic acid, S,S-ethylenediamine disuccinic acid or nitrilotriacetic acid. Soil solution concentration of U was monitored during 2 weeks. All amendments increased U concentration in soil solution, but citric acid and NH(4)-citrate/citric acid mixture were most effective, with up to 479-fold increase. For oxalic acid, S,S-ethylenediamine disuccinic acid and nitrilotriacetic acid, the increase ranged from 10-to 100-fold. The highest concentrations were observed 1 to 7 days after treatment, after which U levels in soil solution gradually decreased. All amendments induced a temporary increase of soil solution pH and TOC that could not be correlated with the release of U in the soil solution. Thermodynamic stability constants (log K) of complexes did not predict the relative efficiency of the selected biodegradable amendments on U release in soil solution. Amendments efficiency was better predicted by the relative affinity of the chelate for Fe compared to U. PMID:18061243

  7. Microemulsion-enhanced remediation of soils contaminated with organochlorine pesticides.

    PubMed

    Zhang, Yanlin; Wong, Jonathan W C; Zhao, Zhenyong; Selvam, Ammaiyappan

    2011-12-01

    Soil contaminated by organic pollutants, especially chlorinated aromatic compounds such as DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane), is an environmental concern because of the strong sorption of organochlorine pesticide onto the soil matrix and persistence in the environment. The remediation of organochlorine pesticide contaminated soils through microemulsion is an innovative technology to expedite this process. The remediation efficiency was evaluated by batch experiments through studying the desorption of DDT and hexachlorocyclohexane (y-HCH) and sorption of microemulsion composed of Triton X-100, 1-pentanol and linseed oil in the soil-surfactant-water suspension system. The reduction of desorption efficiency caused by the sorption loss of microemulsion components onto the soil could be corrected by the appropriate adjustment of C/S (Cosurfactant/Surfactant) and O/S (Oil/Surfactant) ratio. The C/S and O/S ratios of 1:2 and 3:20 were suitable to desorb DDT and gamma-HCH from the studied soils because of the lower sorption of Triton X-100 onto the soil. Inorganic salts added in microemulsion increased the pesticides desorption efficiency of pesticides and calcium chloride has a stronger ability to enhance the desorption of DDT than sodium chloride. From the remediation perspective, the balance of surfactant or cosurfactant sorbed to soil and desorption efficiency should be taken into consideration to enhance the remediation of soils contaminated by organochlorine pesticides. PMID:22439580

  8. Real-Time Identification and Characterization of Asbestos and Concrete Materials with Radioactive Contamination

    SciTech Connect

    Xu, George; Zhang, Xi-Cheng

    1999-06-01

    Concrete and asbestos-containing materials were widely used in U.S. Department of Energy (DOE) building construction in the 1940s and 1950s. Over the years, many of these porous building materials have been contaminated with radioactive sources, on and below the surface. This intractable radioactive-and-hazardous- asbestos mixed-waste-stream has created a tremendous challenge to DOE decontamination and decommissioning (D&D) project managers. The current practice to identify asbestos and to characterize radioactive contamination depth profiles involve bore sampling, and is inefficient, costly, and unsafe. A three-year research project was started on 10/1/98 at Rensselaer with the following ultimate goals: (1) development of novel non-destructive methods for identifying the hazardous asbestos in real-time and in-situ, and (2) development of new algorithms and apparatus for characterizing the radioactive contamination depth profile in real-time and in-situ.

  9. Real-Time Identification and Characterization of Asbestos and Concrete Materials with Radioactive Contamination

    SciTech Connect

    Xu, George; Zhang, Xi-Cheng

    2000-06-01

    Concrete and asbestos-containing materials were widely used in U.S. Department of Energy (DOE) building construction in the 1940s and 1950s. Over the years, many of these porous building materials have been contaminated with radioactive sources, on and below the surface. This intractable radioactive-and-hazardous-asbestos mixed-waste stream has created a tremendous challenge to DOE decontamination and decommissioning (D&D) project managers. The current practice to identify asbestos and to characterize radioactive contamination depth profiles in based solely on bore sampling, which is inefficient, costly, and unsafe. A three-year research project was started 1998 at Rensselaer with the following ultimate goals: (1) development of novel non-destructive methods for identifying the hazardous asbestos in real-time and in-situ, and (2) development of new algorithms and apparatus for characterizing the radioactive contamination depth profile in real-time and in-situ.

  10. Evaluation of ambient dose equivalent rates influenced by vertical and horizontal distribution of radioactive cesium in soil in Fukushima Prefecture.

    PubMed

    Malins, Alex; Kurikami, Hiroshi; Nakama, Shigeo; Saito, Tatsuo; Okumura, Masahiko; Machida, Masahiko; Kitamura, Akihiro

    2016-01-01

    The air dose rate in an environment contaminated with (134)Cs and (137)Cs depends on the amount, depth profile and horizontal distribution of these contaminants within the ground. This paper introduces and verifies a tool that models these variables and calculates ambient dose equivalent rates at 1 m above the ground. Good correlation is found between predicted dose rates and dose rates measured with survey meters in Fukushima Prefecture in areas contaminated with radiocesium from the Fukushima Dai-ichi Nuclear Power Plant accident. This finding is insensitive to the choice for modeling the activity depth distribution in the ground using activity measurements of collected soil layers, or by using exponential and hyperbolic secant fits to the measurement data. Better predictions are obtained by modeling the horizontal distribution of radioactive cesium across an area if multiple soil samples are available, as opposed to assuming a spatially homogeneous contamination distribution. Reductions seen in air dose rates above flat, undisturbed fields in Fukushima Prefecture are consistent with decrement by radioactive decay and downward migration of cesium into soil. Analysis of remediation strategies for farmland soils confirmed that topsoil removal and interchanging a topsoil layer with a subsoil layer result in similar reductions in the air dose rate. These two strategies are more effective than reverse tillage to invert and mix the topsoil. PMID:26408835

  11. Clean-up criteria for remediation of contaminated soils

    SciTech Connect

    Nguyen, H.D.; Wilson, J.R.; Sato, Chikashi

    1997-08-01

    {open_quotes}How clean is clean?{close_quotes} is a question commonly raised in the remediation of contaminated soils. To help with the answer, criteria are proposed to serve as guidelines for remedial actions and to define a clean-up level such that the remaining contaminant residuals in the soil will not violate the Drinking Water Standards (DWS). The equations for computing those criteria are developed from the principle of conservation of mass and are functions of the maximum concentration level in the water (MCL) and the sorption coefficient. A multiplier, ranging from 10 to 1000, is also factored into the soil standard equation to reflect the effectiveness of various remediation techniques. Maximum allowable concentration in the soil (MSCL) is presented for several contaminants which are being regulated at the present time. Future modifications are recommended for better estimates of the MSCLs as additional transport mechanisms are incorporated to account for other potentially dominant effects.

  12. REMEDIATION OF CONTAMINATED SOILS BY SOLVENT FLUSHING

    EPA Science Inventory

    Solvent flushing is a potential technique for remediating a waste disposal/spill site contaminated with organic chemicals. This technique involves the injection of a solvent mixture (e.g., water plus alcohols) that enhances contaminant solubility, reduces the retardation factor, ...

  13. Chemical contamination and transformation of soils in hydrocarbon production regions

    NASA Astrophysics Data System (ADS)

    Zamotaev, I. V.; Ivanov, I. V.; Mikheev, P. V.; Nikonova, A. N.

    2015-12-01

    The current concepts of soil pollution and transformation in the regions of hydrocarbon production have been reviewed. The development of an oil field creates extreme conditions for pedogenesis. Tendencies in the radial migration, spatial distribution, metabolism, and accumulation of pollutants (oil, oil products, and attendant heavy metals) in soils of different bioclimatic zones have been analyzed. The radial and lateral mobility of pollution halos is a universal tendency in the technogenic transformation of soils and soil cover in the regions of hydrocarbon production. The biodegradation time of different hydrocarbon compounds strongly varies under different landscape conditions, from several months to several tens of years. The transformation of original (mineral and organic) soils to their technogenic modifications (mechanically disturbed, chemically contaminated, and chemo soils and chemozems) occurs in the impact zone of technogenic hydrocarbon fluxes under any physiographical conditions. The integrated use of the existing methods for the determination of the total content and qualitative composition of bituminous substances and polyaromatic hydrocarbons in combination with the chromatographic determination of normal alkanes and hydrocarbon gases, as well as innovative methods of studies, allows revealing new processes and genetic relationships in soils and studying the functioning of soils and soil cover. The study of the hydrocarbon contamination of soils is important for development of restoration measures and lays the groundwork for the ecological and hygienic regulation based on the zonation of soil and landscape resistance to different pollutants.

  14. Impact of radioactive waste heat on soil temperatures

    SciTech Connect

    Robinson, B.A.; Gable, C.W.; Lowman, J.P.

    1999-01-04

    Consideration of the impact of radioactive waste heat is necessary for many aspects of potential repository design. Waste heat will alter the mineralogy of the host rock, and may change the character of the zeolitic units below the potential repository that are likely to be the primary natural barriers to radionuclide migration. The impact of waste heat on the near-surface temperature within the soil zone is the focus of the present study. Since 1990, the Nuclear Waste Technical Review Board (NWTRB) has raised the issue of potential impacts on the aboveground ecosystem from increases in soil temperatures. This study is a first step toward understanding the relevant heat transfer processes that controls the near-surface thermal regime and to place bounds on the expected timing and magnitude of the temperature rise. Two-dimensional, site scale thermohydrologic calculations will be used to simulate the large-scale thermohydrologic processes that will feed heat to the soil zone. The potential influence of this heat on soil-zone temperatures will then be examined in a series of simplified one-dimensional model calculations. In future efforts the measured soil-zone temperature variations in the air will be used to calibrate the model, which will tighten the bounds on the possible temperature rise. This study is a precursor to more detailed, three-dimensional simulations with a calibrated model. If it is determined that direct coupling of the site scale and soil zones would be beneficial, this will be done as well.

  15. DOE`s radioactively - contaminated metal recycling: The policy and its implementation

    SciTech Connect

    Warren, S.; Rizkalla, E.

    1997-02-01

    In 1994, the Department of Energy`s Office of Environmental Restoration initiated development of a recycling policy to minimize the amount of radioactively-contaminated metal being disposed of as waste. During the following two years, stakeholders (including DOE and contractor personnel, regulators, members of the public, and representatives of labor and industry) were invited to identify key issues of concern, and to provide input on the final policy. As a result of this process, a demonstration policy for recycling radioactively-contaminated carbon steel resulting from decommissioning activities within the Environmental Management program was signed on September 20, 1996. It specifically recognizes that the Office of Environmental Management has a tremendous opportunity to minimize the disposal of metals as waste by the use of disposal containers fabricated from contaminated steel. The policy further recognizes the program`s demand for disposal containers, and it`s role as the major generator of radioactively-contaminated steel.

  16. Coupling Sorption to Soil Weathering during Reactive Transport: Impacts of Mineral Transformation and Sorbate Aging on Contaminant Speciation and Mobility

    SciTech Connect

    Carl I. Steefel; Aaron Thompson; Jon Chorover

    2006-06-01

    The Hanford subsurface has become contaminated with highly alkaline, radioactive waste generated as a result of weapons production. The radioactive brine was stored in underground storage tanks, a number of which developed leaks and contaminated the surrounding subsurface. The high pH and ionic strength of these wastes has been predicted to accelerate the degree of soil weathering to produce new mineral phases--cancrinite and sodalite among the most abundant. Previous work has demonstrated that Cs and Sr, which along with I represent the most radioactive components in the waste, are sequestered by these neo-formed solids. The present work is aimed at assessing the stability of these neo-formed solids, with special emphasis on the degree of Cs, Sr and I release under ambient (neutral pH, low ionic strength) conditions expected to return to the Hanford area after the caustic radioactive brine waste is removed.

  17. Soil biogeochemistry, plant physiology and phytoremediation of cadmium contaminated soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cadmium (Cd) loading in soil and the environment has been accelerated worldwide due to enhanced industrialization and intensified agricultural production, particularly in the developing countries. Soil Cd pollution, resulting from both anthropogenic and geogenic sources, has posed an increasing chal...

  18. Solubility measurement of uranium in uranium-contaminated soils

    SciTech Connect

    Lee, S.Y.; Elless, M.; Hoffman, F.

    1993-08-01

    A short-term equilibration study involving two uranium-contaminated soils at the Fernald site was conducted as part of the In Situ Remediation Integrated Program. The goal of this study is to predict the behavior of uranium during on-site remediation of these soils. Geochemical modeling was performed on the aqueous species dissolved from these soils following the equilibration study to predict the on-site uranium leaching and transport processes. The soluble levels of total uranium, calcium, magnesium, and carbonate increased continually for the first four weeks. After the first four weeks, these components either reached a steady-state equilibrium or continued linearity throughout the study. Aluminum, potassium, and iron, reached a steady-state concentration within three days. Silica levels approximated the predicted solubility of quartz throughout the study. A much higher level of dissolved uranium was observed in the soil contaminated from spillage of uranium-laden solvents and process effluents than in the soil contaminated from settling of airborne uranium particles ejected from the nearby incinerator. The high levels observed for soluble calcium, magnesium, and bicarbonate are probably the result of magnesium and/or calcium carbonate minerals dissolving in these soils. Geochemical modeling confirms that the uranyl-carbonate complexes are the most stable and dominant in these solutions. The use of carbonate minerals on these soils for erosion control and road construction activities contributes to the leaching of uranium from contaminated soil particles. Dissolved carbonates promote uranium solubility, forming highly mobile anionic species. Mobile uranium species are contaminating the groundwater underlying these soils. The development of a site-specific remediation technology is urgently needed for the FEMP site.

  19. SOLVENT EXTRACTION AND SOIL WASHING TREATMENT OF CONTAMINATED SOILS FROM WOOD PRESERVING SITES: BENCH SCALE STUDIES

    EPA Science Inventory

    Bench-scale solvent extraction and soil washing studies were performed on soil samples obtained from three abandoned wood preserving sites that included in the NPL. The soil samples from these sites were contaminated with high levels of polyaromatic hydrocarbons (PAHs), pentachlo...

  20. RESULTS OF TREATMENT EVALUATIONS OF CONTAMINATED SOILS

    EPA Science Inventory

    Soil and debris from Superfund sites must be treated to minimize their threat to human health and the environment as part of remedial actions at such sites. Studies were conducted on the effectiveness with which five treatment processes removed or immobilized synthetic soils cont...

  1. Soil contamination with 90Sr in the near zone of the Chernobyl accident.

    PubMed

    Kashparov, V A; Lundin, S M; Khomutinin, Y V; Kaminsky, S P; Levchuk, S E; Protsak, V P; Kadygrib, A M; Zvarich, S I; Yoschenko, V I; Tschiersch, J

    2001-01-01

    Representative large-scale soil sampling on a regular grid of step width about 1 km was carried out for the first time in the near zone of the Chernobyl accident (radius 36 km). An integrated map of terrestrial 90Sr contamination density in the 30 km exclusion zone (scale 1:200,000) has been created from the analysed samples. Maps of the main agrochemical characteristics of the soils, which determine the fuel particle dissolution rates and the contamination of vegetation, were produced. The total contents of 90Sr on the ground surface of the 30 km zone in Ukraine (without the reactor site and the radioactive waste storages) was about 810 TBq (8.1 x 10(+14) Bq) in 1997, which corresponds to 0.4-0.5% of the Chernobyl reactor inventory at the time of the accident. This assessment is 3-4 times lower than previous estimates. PMID:11468820

  2. Biochar: an effective amendment for remediating contaminated soil.

    PubMed

    Kong, Lu-Lu; Liu, Wei-Tao; Zhou, Qi-Xing

    2014-01-01

    Biochar is a carbon-rich material derived from incomplete combustion of biomass.Applying biochar as an amendment to treat contaminated soils is receiving increasing attention, and is a promising way to improve soil quality. Heavy metals are persistent and are not environmentally biodegradable. However, they can be stabilized in soil by adding biochar. Moreover, biochar is considered to be a predominant sorptive agent for organic pollutants, having a removal efficiency of about 1 order of magnitude higher than does soil/sediment organic matter or their precursor substances alone.When trying to stabilize organic and inorganic pollutants in soil, several features of biochar' s sorption capacity should be considered, viz., the nature of the pollutants to be remediated, how the biochar is prepared, and the complexity of the soil systemin which biochar may be used. In addition, a significant portion of the biochar or some of its components that are used to remediate soils do change over time through abiotic oxidation and microbial decomposition. This change process is commonly referred to as "aging:" Biochar "aging" in nature is inevitable, and aged biochar exhibits an effect that is totally different than non-aged biochar on stabilizing heavy metals and organic contaminants in soils.Studies that have been performed to date on the use of biochar to remediate contaminated soil are insufficient to allow its use for wide-scale field application.Therefore, considerable new data are necessary to expand both our understanding of how biochar performs in the field, and where it can be best used in the future for soil remediation. For example, how biochar and soil biota (microbial and faunal communities)interact in soils is still poorly understood. Moreover, studies are needed on how to best remove new species of heavy metals, and on how biochar aging affects sorption capacity are also needed. PMID:24162093

  3. DEVELOPMENTS IN CHEMICAL TREATMENT OF CONTAMINATED SOIL

    EPA Science Inventory

    The U.S. Environmental Protection Agency's Office of Research and Development (ORD) is examining processes for remedial action at Superfund sites, and corrective action at operating disposal sites. ecent legislation emphasizes destruction and detoxification of contaminants, rathe...

  4. Environmental projects. Volume 14: Removal of contaminated soil and debris

    NASA Technical Reports Server (NTRS)

    Kushner, Len

    1992-01-01

    Numerous diverse activities at the Goldstone Deep Space Communications Complex (GDSCC) are carried out in support of six parabolic dish antennas. Some of these activities can result in possible spills or leakages of hazardous materials and wastes stored both above ground in steel drums and below ground in underground storage tanks (UST's). These possible leaks or spills, along with the past practice of burial of solid debris and waste in trenches and pits, could cause local subsurface contamination of the soil. In 1987, the Jet Propulsion Laboratory (JPL), retained Engineering-Science, Inc. (E-S), Pasadena, California, to identify the specific local areas within the GDSCC with subsurface soil contamination. The E-S study determined that some of the soils at the Apollo Site and the Mars Site were contaminated with hydrocarbons, while soil at a nonhazardous waste dumpsite at the Mojave Base site was contaminated with copper. This volume is a JPL-expanded version of the PE209 E-S report, and it also reports that all subsurface contaminated soils at the GDSCC were excavated, removed, and disposed of in an environmentally acceptable way, and the excavations were backfilled and covered in accordance with accepted Federal, State, and local environmental rules and regulations.

  5. Use of passive sampling devices to determine soil contaminant concentrations

    SciTech Connect

    Johnson, K.A. |; Hooper, M.J.; Weisskopf, C.P.

    1996-12-31

    The effective remediation of contaminated sites requires accurate identification of chemical distributions. A rapid sampling method using passive sampling devices (PSDs) can provide a thorough site assessment. We have been pursuing their application in terrestrial systems and have found that they increase the ease and speed of analysis, decrease solvent usage and overall cost, and minimize the transport of contaminated soils. Time and cost savings allow a higher sampling frequency than is generally the case using traditional methods. PSDs have been used in the field in soils of varying physical properties and have been successful in estimating soil concentrations ranging from 1 {mu}g/kg (parts per billion) to greater than 200 mg/kg (parts per million). They were also helpful in identifying hot spots within the sites. Passive sampling devices show extreme promise as an analytical tool to rapidly characterize contaminant distributions in soil. There are substantial time and cost savings in laboratory personnel and supplies. By selectively excluding common interferences that require sample cleanup, PSDs can be retrieved from the field and processed rapidly (one technician can process approximately 90 PSDs in an 8-h work day). The results of our studies indicate that PSDs can be used to accurately estimate soil contaminant concentrations and provide lower detection limits. Further, time and cost savings will allow a more thorough and detailed characterization of contaminant distributions. 13 refs., 4 figs., 2 tabs.

  6. Bioremediation of industrially contaminated soil using compost and plant technology.

    PubMed

    Taiwo, A M; Gbadebo, A M; Oyedepo, J A; Ojekunle, Z O; Alo, O M; Oyeniran, A A; Onalaja, O J; Ogunjimi, D; Taiwo, O T

    2016-03-01

    Compost technology can be utilized for bioremediation of contaminated soil using the active microorganisms present in the matrix of contaminants. This study examined bioremediation of industrially polluted soil using the compost and plant technology. Soil samples were collected at the vicinity of three industrial locations in Ogun State and a goldmine site in Iperindo, Osun State in March, 2014. The compost used was made from cow dung, water hyacinth and sawdust for a period of twelve weeks. The matured compost was mixed with contaminated soil samples in a five-ratio pot experimental design. The compost and contaminated soil samples were analyzed using the standard procedures for pH, electrical conductivity (EC), organic carbon (OC), total nitrogen (TN), phosphorus, exchangeable cations (Na, K, Ca and Mg) and heavy metals (Fe, Mn, Cu, Zn and Cr). Kenaf (Hibiscus cannabinus) seeds were also planted for co-remediation of metals. The growth parameters of Kenaf plants were observed weekly for a period of one month. Results showed that during the one-month remediation experiment, treatments with 'compost-only' removed 49 ± 8% Mn, 32 ± 7% Fe, 29 ± 11% Zn, 27 ± 6% Cu and 11 ± 5% Cr from the contaminated soil. On the other hand, treatments with 'compost+plant' remediated 71 ± 8% Mn, 63 ± 3% Fe, 59 ± 11% Zn, 40 ± 6% Cu and 5 ± 4% Cr. Enrichment factor (EF) of metals in the compost was low while that of Cu (EF=7.3) and Zn (EF=8.6) were high in the contaminated soils. Bioaccumulation factor (BF) revealed low metal uptake by Kenaf plant. The growth parameters of Kenaf plant showed steady increments from week 1 to week 4 of planting. PMID:26551220

  7. Electrokinetics for removal of low-level radioactivity from soil

    SciTech Connect

    Pamukcu, S.; Wittle, J.K.

    1993-03-01

    The electrokinetic process is an emerging technology for in situ soil decontamination in which chemical species, both ionic and nonionic, are transported to an electrode site in soil. These products are subsequently removed from the ground via collection systems engineered for each specific application. The work presented here describes part of the effort undertaken to investigate electrokinetically enhanced transport of soil contaminants in synthetic systems. These systems consisted of clay or clay-sand mixtures containing known concentrations of a selected heavy-metal salt solution. These metals included surrogate radionuclides such as Sr, Cs and U, and an anionic species of Cr. Degree of removal of these metals from soil by the electrokinetic treatment process was assessed through the metal concentration profiles generated across the soil between the electrodes. Removals of some metal species up to 99% were achieved at the anode or cathode end of the soil upon 24 to 48 hours of treatment or a maximum of 1 pore volume of water displacement toward the cathode compartment. Transient pH change through the soil had an effect on the metal movement, as evidenced by accumulation of the metals at the discharge ends of the soil specimens. This accumulation was attributed to the precipitation of the metal and increased cation retention capacity of the clay in high pH environment at the cathode end. In general, the reduced mobility and dissociation of the ionic species as they encounter areas of higher ionic concentration in their path of migration resulted in the accumulation of the metals at the discharge ends of the soil specimens.

  8. Innovative treatment for TCE-contaminated saturated clay soils

    SciTech Connect

    West, O.R.; Cameron, P.A.; Smuin, D.R.

    1995-12-31

    This paper describes the evaluation of mixed region vapor stripping (MRVS) coupled with calcium oxide conditioning for removing trichloroethylene (TCE) for a site underlain by saturated clay soils. Volatile organic compound removal during MRVS with and without calcium oxide conditioning were simulated using a previously developed model. The results of the modeling were compared with laboratory MRVS tests on undisturbed soil cores taken from the study site. The modeling results were consistent with laboratory simulations of MRVS on field-contaminated soils from the study site, and showed that calcium oxide conditioning is an effective method for enhancing VOC removal efficiencies in saturated clay soils.

  9. EVALUATION OF REMEDIATION TECHNOLOGIES FOR PLUTONIUM CONTAMINATED SOIL

    SciTech Connect

    Hoeffner, S. L.; Navratil, J. D.; Torrao, G.; Smalley, R.

    2002-02-25

    Soils contaminated with radionuclides are an environmental concern at most Department of Energy (DOE) sites. Clean up efforts at many of these sites are ongoing using conventional remediation techniques. These remediation techniques are often expensive and may not achieve desired soil volume reduction. Several studies using alternative remediation techniques have been performed on plutonium-contaminated soils from the Nevada Test Site. Results to date exhibit less than encouraging results, but these processes were often not fully optimized, and other approaches are possible. Clemson University and teaming partner Waste Policy Institute, through a cooperative agreement with the National Environmental Technologies Laboratory, are assisting the Nevada Test Site (NTS) in re-evaluating technologies that have the potential of reducing the volume of plutonium contaminated soil. This efforts includes (1) a through literature review and summary of (a) NTS soil characterization and (b) volume reduction treatment technologies applied to plutonium-contaminated NTS soils, (2) an interactive workshop for vendors, representatives from DOE sites and end-users, and (3) bench scale demonstration of applicable vendor technologies at the Clemson Environmental Technologies Laboratory.

  10. Release of polyaromatic hydrocarbons from coal tar contaminated soils

    SciTech Connect

    Priddy, N.D.; Lee, L.S.

    1996-11-01

    A variety of process wastes generated from manufactured gas production (MGP) have contaminated soils and groundwater at production and disposal sites. Coal tar, consisting of a complex mixture of hydrocarbons present as a nonaqueous phase liquid, makes up a large portion of MGP wastes. Of the compounds in coal tar, polyaromatic hydrocarbons (PAHs) are the major constituents of environmental concern due to their potential mutagenic and carcinogenic hazards. Characterization of the release of PAHs from the waste-soil matrix is essential to quantifying long-term environmental impacts in soils and groundwater. Currently, conservative estimates for the release of PAHs to the groundwater are made assuming equilibrium conditions and using relationships derived from artificially contaminated soils. Preliminary work suggests that aged coal tar contaminated soils have much lower rates of desorption and a greater affinity for retaining organic contaminants. To obtain better estimates of desorption rates, the release of PAHs from a coal tar soil was investigated using a flow-interruption, miscible displacement technique. Methanol/water solutions were employed to enhance PAH concentrations above limits of detection. For each methanol/water solution employed, a series of flow interrupts of varying times was invoked. Release rates from each methanol/water solution were estimated from the increase in concentration with duration of flow interruption. Aqueous-phase release rates were then estimated by extrapolation using a log-linear cosolvency model.

  11. Electromigration of Contaminated Soil by Electro-Bioremediation Technique

    NASA Astrophysics Data System (ADS)

    Azhar, A. T. S.; Nabila, A. T. A.; Nurshuhaila, M. S.; Shaylinda, M. Z. N.; Azim, M. A. M.

    2016-07-01

    Soil contamination with heavy metals poses major environmental and human health problems. This problem needs an efficient method and affordable technological solution such as electro-bioremediation technique. The electro-bioremediation technique used in this study is the combination of bacteria and electrokinetic process. The aim of this study is to investigate the effectiveness of Pseudomonas putida bacteria as a biodegradation agent to remediate contaminated soil. 5 kg of kaolin soil was spiked with 5 g of zinc oxide. During this process, the anode reservoir was filled with Pseudomonas putida while the cathode was filled with distilled water for 5 days at 50 V of electrical gradient. The X-Ray Fluorescent (XRF) test indicated that there was a significant reduction of zinc concentration for the soil near the anode with 89% percentage removal. The bacteria count is high near the anode which is 1.3x107 cfu/gww whereas the bacteria count at the middle and near the cathode was 5.0x106 cfu/gww and 8.0x106 cfu/gww respectively. The migration of ions to the opposite charge of electrodes during the electrokinetic process resulted from the reduction of zinc. The results obtained proved that the electro-bioremediation reduced the level of contaminants in the soil sample. Thus, the electro-bioremediation technique has the potential to be used in the treatment of contaminated soil.

  12. Soil contamination by petroleum products. Southern Algerian case

    NASA Astrophysics Data System (ADS)

    Belabbas, Amina; Boutoutaou, Djamel; Segaï, Sofiane; Segni, Ladjel

    2016-07-01

    Contamination of soil by petroleum products is a current problem in several countries in the world. In Algeria, this negative phenomenon is highly remarked in Saharan region. Numerous studies at the University of Ouargla that we will review in this paper, have tried to find an effective solution to eliminate the hydrocarbons from the soil by the technique of "biodegradation" which is a natural process based on microorganisms such as Bacillus megaterium and Pseudomonas aeruginosa. Presence of aboriginal strain Bacillus megaterium in the soil samples with different ages of contamination has shown a strong degradation of pollutants. This strain chosen for its short time of generation which is performing as seen the best yields of elimination of hydrocarbons assessed at 98 % biostimule by biosurfactant, also 98% on a sample wich bioaugmente by urea, and 86 % of the sample which biostimule by nutrient solution. The rate of biodegradation of the contaminated soil by crude oil using the strain Pseudomonas aeruginosa is higher in the presence of biosurfactant 53 % that in his absence 35 %. Another elimination technique wich is washing the contaminated soil's sample by centrifugation in the presence of biosurfactant where The rate of hydrocarbons mobilized after washing soil by centrifugation is of 50 % and 76 % but without centrifugation it was of 46% to 79%. Those processes have great capacity in the remobilization of hydrocarbons and acceleration of their biodegradation; thus, they deserve to be further developed in order to prevent environmental degradation in the region of Ouargla.

  13. [Influence of the consumption of radioactive contaminated food on the formation of the irradiation levels and health of the inhabitants of radioactive contaminated regions of Ukraine].

    PubMed

    Khomenko, I M; Omel'yanets, N I

    2014-01-01

    Within all these years after the Chernobyl disaster the population of contaminated areas of the Rivne region was shown to consume radioactive contaminated foodstuffs. The main components of the formation of the internal irradiation of the population in them were and remain locally sourced milk and meat, forest mushrooms and berries. After 1991, the largest annual internal doses in persons observed in 1997 varied from 2,2 to 1,45 mSv/year and in 2011--in the inhabitants of the village of El'no they were yet reaching 1.43 mSv/year. After 2003, exposure levels in most inhabitatants of affected areas exceeded the criterion specified by national legislation for residents of the tightened radioecological control zone (0,5 mSv/year). The long-term residence in the contaminated area, elevated levels of chronic internal exposure, lack of radioactively sound foodstuffs and involuntary consumption in 1987-2011 radioactively contaminated food of local production were noted to led to an increase in general morbidity, and incidence of endocrine diseases rate and their separate nosological forms. PMID:24749279

  14. Field demonstration of soil slurry bioreactor technology for the remediation of explosives-contaminated soils

    SciTech Connect

    Hampton, M.L.; Sisk, W.E.

    1995-11-01

    The past production and handling of conventional munitions has resulted in explosives contamination of the soils at various military facilities. The principal explosive contaminants are trinitrotoluene (TNT), cyclotrimethylenetrinitramine (RDX), and cyclotetramethylenetetranitramine (HMX). Depending on the concentrations present, these explosives-contaminated soils pose both a reactivity and toxicity hazard and the potential for groundwater contamination. Bioremediation technologies are currently being developed by the U.S. Army Environmental Center as cost-effective alternatives to the current proven technology, high temperature incineration. A technology which is gaining popularity in the remediation industry is the use of soil slurry biodegradation systems in which an aqueous slurry is created by combining soils or sludge with water. Previous studies using soils contaminated with explosives from Joliet Army Ammunition Plant (JAAP) demonstrated the feasibility of this technology. A field demonstration to determine the feasibility of using Soil Slurry Sequencing Batch Reactors (SS-SBRs) to treat explosives-contaminated soils is being conducted at JAAP. Key factors to be investigated include the percent reduction of explosives and the identification of degradation products. In addition, the efficiency of reactor operations using different soil replacement volumes will be examined.

  15. Measurement of radioactivity levels and assessment of radioactivity hazards of soil samples in Karaman, Turkey.

    PubMed

    Agar, O; Boztosun, I; Korkmaz, M E; Özmen, S F

    2014-12-01

    In this study, the levels of the natural and artificial radioactivity in soil samples collected from surrounding of Karaman in Turkey were measured. Activity concentrations of the concerned radionuclides were determined by gamma-ray spectrometry using a high-purity germanium detector with a relative efficiency of 40 % at 1.332 MeV. The results obtained for the (238)U series ((226)Ra, (214)Pb and (214)Bi), (232)Th series ((228)Ac), (40)K and fission product (137)Cs are discussed. To evaluate the radiological hazard of radioactivity in samples, the radium equivalent activity (Raeq), the absorbed dose rate (D), the annual effective dose and the external (Hex) and internal hazard index (Hin) were calculated and presented in comparison with the data collected from different areas in the world and Turkey. PMID:24587487

  16. Sustainable remediation of mercury contaminated soils by thermal desorption.

    PubMed

    Sierra, María J; Millán, Rocio; López, Félix A; Alguacil, Francisco J; Cañadas, Inmaculada

    2016-03-01

    Mercury soil contamination is an important environmental problem that needs the development of sustainable and efficient decontamination strategies. This work is focused on the application of a remediation technique that maintains soil ecological and environmental services to the extent possible as well as search for alternative sustainable land uses. Controlled thermal desorption using a solar furnace at pilot scale was applied to different types of soils, stablishing the temperature necessary to assure the functionality of these soils and avoid the Hg exchange to the other environmental compartments. Soil mercury content evolution (total, soluble, and exchangeable) as temperature increases and induced changes in selected soil quality indicators are studied and assessed. On total Hg, the temperature at which it is reduced until acceptable levels depends on the intended soil use and on how restrictive are the regulations. For commercial, residential, or industrial uses, soil samples should be heated to temperatures higher than 280 °C, at which more than 80 % of the total Hg is released, reaching the established legal total Hg level and avoiding eventual risks derived from high available Hg concentrations. For agricultural use or soil natural preservation, conversely, maintenance of acceptable levels of soil quality limit heating temperatures, and additional treatments must be considered to reduce available Hg. Besides total Hg concentration in soils, available Hg should be considered to make final decisions on remediation treatments and potential future uses. Graphical Abstract Solar energy use for remediation of soils affected by mercury. PMID:26545893

  17. Evaluation of electrokinetic remediation of arsenic-contaminated soils.

    PubMed

    Kim, Soon-Oh; Kim, Won-Seok; Kim, Kyoung-Woong

    2005-09-01

    The potential of electrokinetic (EK) remediation technology has been successfully demonstrated for the remediation of heavy metal-contaminated fine-grained soils through laboratory scale and field application studies. Arsenic contamination in soil is a serious problem affecting both site use and groundwater quality. The EK technology was evaluated for the removal of arsenic from two soil samples; a kaolinite soil artificially contaminated with arsenic and an arsenic-bearing tailing-soil taken from the Myungbong (MB) gold mine area. The effectiveness of enhancing agents was investigated using three different types of cathodic electrolytes; deionized water (DIW), potassium phosphate (KH(2)PO(4)) and sodium hydroxide (NaOH). The results of the experiments on the kaolinite show that the potassium phosphate was the most effective in extracting arsenic, probably due to anion exchange of arsenic species by phosphate. On the other hand, the sodium hydroxide seemed to be the most efficient in removing arsenic from the tailing-soil. This result may be explained by the fact that the sodium hydroxide increased the soil pH and accelerated ionic migration of arsenic species through the desorption of arsenic species as well as the dissolution of arsenic-bearing minerals. PMID:16237600

  18. Preliminary Experimental Analysis of Soil Stabilizers for Contamination Control

    SciTech Connect

    Lagos, L.; Varona, J.; Zidan, A.; Gudavalli, R.; Wu, Kuang-His

    2006-07-01

    A major focus of Department of Energy's (DOE's) environmental management mission at the Hanford site involves characterizing and remediating contaminated soil and groundwater; stabilizing contaminated soil; remediating disposal sites; decontaminating and decommissioning structures, and demolishing former plutonium production process buildings, nuclear reactors, and separation plants; maintaining inactive waste sites; transitioning facilities into the surveillance and maintenance program; and mitigating effects to biological and cultural resources from site development and environmental cleanup and restoration activities. For example, a total of 470,914 metric tons of contaminated soil from 100 Areas remediation activities were disposed at the Environmental Restoration Disposal Facility (ERDF) during 2004. The Applied Research Center (ARC) at Florida International University (FIU) is supporting the Hanford's site remediation program by analyzing the effectiveness of several soil stabilizers (fixatives) for contamination control during excavation activities. The study is focusing on determining the effects of varying soil conditions, temperature, humidity and wind velocity on the effectiveness of the candidate stabilizers. The test matrix consists of a soil penetration-depth study, wind tunnel experiments for determination of threshold velocity, and temperature and moisture-controlled drying/curing experiments. These three set of experiments are designed to verify performance metrics, as well as provide insight into what fundamental forces are altered by the use of the stabilizer. This paper only presents the preliminary results obtained during wind tunnel experiments using dry Hanford soil samples (with 2.7% moisture by weight). These dry soil samples were exposed to varying wind speeds from 2.22 m/sec to 8.88 m/sec. Furthermore, airborne particulate data was collected for the dry Hanford soil experiments using an aerosol analyzer instrument. (authors)

  19. Magnetic mineralogy of heavy metals-contaminated soils

    NASA Astrophysics Data System (ADS)

    Shenggao, L.

    2012-04-01

    Soils around mine and in urban areas are often contaminated by heavy metals derived from industrial and human activities [1, 2]. These contaminated soils are often characterized by a magnetic enhancement on topsoils. Many studies demonstrated that there are significant correlations between heavy metals and various magnetic parameters in contaminated soils, indicating a strong affinity of heavy metals to magnetic minerals. The magnetic particles in contaminated soils were separated by a magnetic separation technique. The rock magnetism, XRD, field emission scanning electron microscopy equiped with an energy-dispersive X-ray analyzer (FESEM/EDX) were used to characterize their magnetic mineralogy. Results of XRD analysis indicated that the magnetic particles separated from heavy metal-contaminated soils are composed of quartz, magnetite, and hematite. Based on the X-ray diffraction peak intensity, the Fe3O4 was identified as the predominant magnetic mineral phase. The high-temperature magnetization (Ms-T) curves of magnetic particles extracted from contaminated soils show a sharp Ms decrease at about 580C (the Curie temperature of magnetite), suggesting that magnetite is the dominant magnetic carrier. The hysteresis loops of contaminated soils are closed at about 100-200 mT which is consistent with the presence of a dominant ferrimagnetic mineral phase. The FESEM analysis showed a great variety of shapes of magnetic particles in contaminated soils. The most common morphology are observed in the form of spherules, with the sizes ranging from 20 to 100 um. The chemical composition of magnetic particles consist mainly of Fe, Si, Al, and Ca with minor heavy metal elements (Cu, Zn, Hg, and Cr). The semi-quantitative Fe content identified by FESEM/EDX ranged from 40 to 90%. Combined studies of rock magnetism, XRD, and FESEM/EDX indicated that magnetic mineral phases responsible for the magnetic enhancement of contaminated soils are anthropogenic origin which are coarse

  20. In situ bioremediation of contaminated unsaturated subsurface soils

    SciTech Connect

    Sims, J.L.; Sims, R.C.; Dupont, R.R.; Matthews, J.E.; Russell, H.H.

    1993-05-01

    An emerging technology for the remediation of unsaturated subsurface soils involves the use of microorganisms to degrade contaminants which are present in such soils. Understanding the processes which drive in situ bioremediation, as well as the effectiveness and efficiency of the utilization of these systems, are issues which have been identified by the Regional Superfund Engineering Forum as concerns of Superfund decision makers. Although in situ bioremediation has been used for a number of years in the restoration of ground water contaminated by petroleum hydrocarbons, it has only been in recent years that in situ systems have been directed toward contaminants in unsaturated subsurface soils. Research has contributed greatly to understanding the biotic, chemical, and hydrologic parameters which contribute to or restrict the application of in-situ bioremediation and has been successful at a number of locations in demonstrating its effectiveness at field scale.

  1. Effects of poultry manure on soil biochemical properties in phthalic acid esters contaminated soil.

    PubMed

    Gao, Jun; Qin, Xiaojian; Ren, Xuqin; Zhou, Haifeng

    2015-12-01

    This study aimed to evaluate the effects of poultry manure (PM) on soil biological properties in DBP- and DEHP-contaminated soils. An indoor incubation experiment was conducted. Soil microbial biomass C (Cmic), soil enzymatic activities, and microbial phospholipid fatty acid (PLFA) concentrations were measured during incubation period. The results indicated that except alkaline phosphatase activity, DBP and DEHP had negative effects on Cmic, dehydrogenase, urease, protease activities, and contents of total PLFA. However, 5 % PM treatment alleviated the negative effects of PAEs on the above biochemical parameters. In DBP-contaminated soil, 5 % PM amendment even resulted in dehydroenase activity and Cmic content increasing by 17.8 and 11.8 % on the day 15 of incubation, respectively. During the incubation periods, the total PLFA contents decreased maximumly by 17.2 and 11.6 % in DBP- and DEHP-contaminated soils without PM amendments, respectively. Compared with those in uncontaminated soil, the total PLFA contents increased slightly and the value of bacPLFA/fugalPLFA increased significantly in PAE-contaminated soils with 5 % PM amendment. Nevertheless, in both contaminated soils, the effects of 5 % PM amendment on the biochemical parameters were not observed with 10 % PM amendment. In 10 % PM-amended soils, DBP and DEHP had little effect on Cmic, soil enzymatic activities, and microbial community composition. At the end of incubation, the effects of PAEs on these parameters disappeared, irrespective of PM amendment. The application of PM ameliorated the negative effect of PAEs on soil biological environment. However, further work is needed to study the effect of PM on soil microbial gene expression in order to explain the change mechanisms of soil biological properties. PMID:26298343

  2. Contamination of Austrian soil with caesium-137.

    PubMed

    Bossew, P; Ditto, M; Falkner, T; Henrich, E; Kienzl, K; Rappelsberger, U

    2001-01-01

    Austria ranks among the countries that have been most strongly affected by the Chernobyl fallout. The mean contamination with 137Cs is 21.0 kBq/m2, of which 18.7 kBq/m2 is due to the Chernobyl accident, whereas global fallout contributes 2.3 kBq/m2. Maximum values of total 137Cs contamination are nearly 200 kBq/m2. Total deposition of Chernobyl 137Cs on Austrian territory is 1.6 PBq or a fraction of around 2% of the 137Cs released from the reactor. 2115 measurements were used to draw the Austrian "caesium map". The geographical pattern of fallout distribution shows regional differences of contamination as high as 1:100. PMID:11398378

  3. Contaminant bioavailability in soils, sediments, and aquatic environments

    PubMed Central

    Traina, Samuel J.; Laperche, Valérie

    1999-01-01

    The aqueous concentrations of heavy metals in soils, sediments, and aquatic environments frequently are controlled by the dissolution and precipitation of discrete mineral phases. Contaminant uptake by organisms as well as contaminant transport in natural systems typically occurs through the solution phase. Thus, the thermodynamic solubility of contaminant-containing minerals in these environments can directly influence the chemical reactivity, transport, and ecotoxicity of their constituent ions. In many cases, Pb-contaminated soils and sediments contain the minerals anglesite (PbSO4), cerussite (PbCO3), and various lead oxides (e.g., litharge, PbO) as well as Pb2+ adsorbed to Fe and Mn (hydr)oxides. Whereas adsorbed Pb can be comparatively inert, the lead oxides, sulfates, and carbonates are all highly soluble in acidic to circumneutral environments, and soil Pb in these forms can pose a significant environmental risk. In contrast, the lead phosphates [e.g., pyromorphite, Pb5(PO4)3Cl] are much less soluble and geochemically stable over a wide pH range. Application of soluble or solid-phase phosphates (i.e., apatites) to contaminated soils and sediments induces the dissolution of the “native” Pb minerals, the desorption of Pb adsorbed by hydrous metal oxides, and the subsequent formation of pyromorphites in situ. This process results in decreases in the chemical lability and bioavailability of the Pb without its removal from the contaminated media. This and analogous approaches may be useful strategies for remediating contaminated soils and sediments. PMID:10097045

  4. Immobilization of uranium in contaminated soil by natural apatite addition

    SciTech Connect

    Mrdakovic Popic, Jelena; Stojanovic, Mirjana; Milosevic, Sinisa; Iles, Deana; Zildzovic, Snezana

    2007-07-01

    Available in abstract form only. Full text of publication follows: The goal of this study was to evaluate the effectiveness of Serbian natural mineral apatite as soil additive for reducing the migration of uranium from contaminated sediments. In laboratory study we investigated the sorption properties of domestic apatite upon different experimental conditions, such as pH, adsorbent mass, reaction period, concentration of P{sub 2}O{sub 5} in apatite, solid/liquid ratio. In second part of study, we did the quantification of uranium in soil samples, taken from uranium mine site 'Kalna', by sequential extraction method. The same procedure was, also, used for uranium determination in contaminated soil samples after apatite addition, in order to determine the changes in U distribution in soil fraction. The obtained results showed the significant level of immobilization (96.7%) upon certain conditions. Increase of %P{sub 2}O{sub 5} in apatite and process of mechano-chemical activation led to increase of immobilization capacity from 17.50% till 91.64%. The best results for uranium binding were obtained at pH 5.5 and reaction period 60 days (98.04%) The sequential extraction showed the presence of uranium (48.2%) in potentially available soil fractions, but with the apatite addition uranium content in these fractions decreased (30.64%), what is considering environmental aspect significant fact. In situ immobilization of radionuclide using inexpensive sequestering agents, such as apatite, is very adequate for big contaminated areas of soil with low level of contamination. This investigation study on natural apatite from deposit 'Lisina' Serbia was the first one of this type in our country. Key words: apatite, uranium, immobilization, soil, contamination. (authors)

  5. Human exposure to soil contaminants in subarctic Ontario, Canada

    PubMed Central

    Reyes, Ellen Stephanie; Liberda, Eric Nicholas; Tsuji, Leonard James S.

    2015-01-01

    Background Chemical contaminants in the Canadian subarctic present a health risk with exposures primarily occurring via the food consumption. Objective Characterization of soil contaminants is needed in northern Canada due to increased gardening and agricultural food security initiatives and the presence of known point sources of pollution. Design A field study was conducted in the western James Bay Region of Ontario, Canada, to examine the concentrations of polychlorinated biphenyls, dichlorodiphenyltrichloroethane and its metabolites (ΣDDT), other organochlorines, and metals/metalloids in potentially contaminated agriculture sites. Methods Exposure pathways were assessed by comparing the estimated daily intake to acceptable daily intake values. Ninety soil samples were collected at random (grid sampling) from 3 plots (A, B, and C) in Fort Albany (on the mainland), subarctic Ontario, Canada. The contaminated-soil samples were analysed by gas chromatography with an electron capture detector or inductively coupled plasma mass spectrometer. Results The range of ΣDDT in 90 soil samples was below the limit of detection to 4.19 mg/kg. From the 3 soil plots analysed, Plot A had the highest ΣDDT mean concentration of 1.12 mg/kg, followed by Plot B and Plot C which had 0.09 and 0.01 mg/kg, respectively. Concentrations of other organic contaminants and metals in the soil samples were below the limit of detection or found in low concentrations in all plots and did not present a human health risk. Conclusion Exposure analyses showed that the human risk was below regulatory thresholds. However, the ΣDDT concentration in Plot A exceeded soil guidelines set out by the Canadian Council of Ministers of the Environment of 0.7 mg/kg, and thus the land should not be used for agricultural or recreational purposes. Both Plots B and C were below threshold limits, and this land can be used for agricultural purposes. PMID:26025557

  6. Extraction of pesticides from contaminated soil using supercritical carbon dioxide

    SciTech Connect

    Hunter, G.B.

    1991-01-01

    The demand for processes to clean up contaminated soils without generating additional contaminants, such as hazardous solvents, is increasing. One approach to minimizing this problem is to use supercritical fluids like light hydrocarbons and CO[sub 2] to extract contaminants from soils. Gases exhibit unique properties under supercritical conditions. They retain the ability to diffuse through the interstitial spaces of solid materials, plus they have the solvating power of liquids. Some examples of extractions using SCFs are caffeine from coffee, cholesterol from eggs, drugs from plants, and nicotine from tobacco. Supercritical CO[sub 2] is an attractive, alternative extraction medium for removal of pesticides from soils. Carbon dioxide is readily available, relatively inexpensive, and if recycled, nonpolluting. Contaminants may be easily recovered by evaporating the CO[sub 2] into an expansion vessel. Supercritical fluid extraction technology is discussed and results are given for the extraction of atrazine, bentazon, alachlor, and permethrin from contaminated soil prepared in the laboratory. Initial studies show >95% removal for these pesticides.

  7. Extraction of pesticides from contaminated soil using supercritical carbon dioxide

    SciTech Connect

    Hunter, G.B.

    1991-12-31

    The demand for processes to clean up contaminated soils without generating additional contaminants, such as hazardous solvents, is increasing. One approach to minimizing this problem is to use supercritical fluids like light hydrocarbons and CO{sub 2} to extract contaminants from soils. Gases exhibit unique properties under supercritical conditions. They retain the ability to diffuse through the interstitial spaces of solid materials, plus they have the solvating power of liquids. Some examples of extractions using SCFs are caffeine from coffee, cholesterol from eggs, drugs from plants, and nicotine from tobacco. Supercritical CO{sub 2} is an attractive, alternative extraction medium for removal of pesticides from soils. Carbon dioxide is readily available, relatively inexpensive, and if recycled, nonpolluting. Contaminants may be easily recovered by evaporating the CO{sub 2} into an expansion vessel. Supercritical fluid extraction technology is discussed and results are given for the extraction of atrazine, bentazon, alachlor, and permethrin from contaminated soil prepared in the laboratory. Initial studies show >95% removal for these pesticides.

  8. Arsenic biotransformation in earthworms from contaminated soils.

    PubMed

    Button, Mark; Jenkin, Gawen R T; Harrington, Chris F; Watts, Michael J

    2009-08-01

    Two species of arsenic (As) resistant earthworm, Lumbricus rubellus and Dendrodrillus rubidus, their host soils and soil excretions (casts) were collected from 23 locations at a former As mine in Devon, UK. Total As concentrations, measured by ICP-MS, ranged from 255 to 13,080 mg kg(-1) in soils, 11 to 877 mg kg(-1) in earthworms and 284 to 4221 mg kg(-1) in earthworm casts from a sub-sample of 10 of the 23 investigated sites. The samples were also measured for As speciation using HPLC-ICP-MS to investigate potential As biotransformation pathways. Inorganic arsenate (As(V)) and arsenite (As(III)) were the only species detected in the soil. As(V) and As(III) were also the dominant species found in the earthworms and cast material together with lower proportions of the organic species methylarsonate (MA(V)), dimethylarsinate (DMA(V)), arsenobetaine (AB) and three arsenosugars. Whilst the inorganic As content of the earthworms increased with increasing As body burden, the concentration of organic species remained relatively constant. These results suggest that the biotransformation of inorganic arsenic to organic species does not contribute to As resistance in the sampled earthworm populations. Quantification of As speciation in the soil, earthworms and cast material allows a more comprehensive pathway for the formation of AB in earthworms to be elucidated. PMID:19657532

  9. Use of Carboxymethyl-beta-cyclodextrin (CMCD) as Flushing Agent for Remediation of Metal Contaminated Soil

    NASA Astrophysics Data System (ADS)

    Skold, M. E.; Thyne, G. D.; McCray, J. E.; Drexler, J. W.

    2005-12-01

    One of the major challenges in remediating soil and ground water is the presence of mixed organic and inorganic contaminants. Due to their very different behavior, research has to a large extent focused on remediation of either organic or inorganic contaminants rather than mixed waste. Cyclodextrins (CDs) are a group of non-toxic sugar based molecules that do not sorb to soil particles and do not experience pore size exclusion. Thus, they have good hydraulic properties. CDs enhance the solubility of organic compounds by forming inclusion complexes between organic contaminants and the non-polar cavity at the center of the CD. By substituting functional groups to the cyclodextrin molecule it can form complexes with heavy metals. Previous studies have shown that carboxymethyl-beta-cyclodextrin (CMCD) can simultaneously complex organic and inorganic contaminants. The aim of this study is to compare how strongly CMCD complexes several common heavy metals, radioactive elements and a common divalent cation. Results from batch experiments show that CMCD has the ability to complex a wide array of heavy metals and radioactive elements. The solubility of metal oxalates and metal oxides clearly increased in the presence of CMCD. Logarithmic conditional formation constants ranged from 3.5 to 6 for heavy metals and from 3 to 6 for radioactive elements. Calcium, which may compete for binding sites, has a logarithmic conditional formation constant of 3.1. Batch experiments performed at 10 and 25 degrees C showed little temperature effect on conditional formation constants. Results from batch experiments were compared to results from column experiments where Pb was sorbed onto hydrous ferric oxide coated sand and subsequently removed by a CMCD solution. The results indicate that CMCD is a potential flushing agent for remediation of mixed waste sites.

  10. Magnetic susceptibility properties of pesticide contaminated volcanic soil

    NASA Astrophysics Data System (ADS)

    Agustine, Eleonora; Fitriani, Dini; Safiuddin, La Ode; Tamuntuan, Gerald; Bijaksana, Satria

    2013-09-01

    Pesticides, unfortunately, are still widely used in many countries as way to eradicate agricultural pests. As they are being used continuously over a long period of time, they accumulate as residues in soils posing serious threats to the environment. In this study, we study the changes in magnetite-rich volcanic soils that were deliberately contaminated by pesticide. Such changes, in any, would be useful in the detection of pesticide residue in contaminated soils. Two different types of magnetically strong volcanic soil from the area near Lembang, West Java, Indonesia were used in this study where they were contaminated with varying concentrations of pesticide. The samples were then measured for magnetic susceptibility at two different frequencies. The measurements were then repeated after a period of three months. We found a reduction of magnetic susceptibility as well as a reduction in SP (superparamagnetic) grains proportion in contaminated soil. These might be caused by pesticide-induced magnetic dissolution as supported by SEM analyses. However the impact of pesticide concentration as well as exposure time on magnetic dissolution is still inconclusive.

  11. Extraction of copper in a contaminated soil onto chabazite

    NASA Astrophysics Data System (ADS)

    Liao, P.-H.; Wang, H. Paul; Hsiao, M.-C.; Eyring, Edward M.; Huang, C.-H.; Jou, C.-J. G.

    2009-04-01

    Copper in a contaminated soil nearby a printed-circuit board waste recycling plant has been extracted onto a microporous molecular sieve (chabazite). The chabazite supported CuO can be used as a chemical looping combustion (CLC) oxygen carrier for CO2 capture. Speciation of copper in the contaminated soil and on the chabazite during CLC has been studied by X-ray absorption near edge structure (XANES) and X-ray absorption fine structure (EXAFS) spectroscopy. By XANES, it is found that about 90% of copper (mainly Cu2+) in the contaminated soil can be extracted and adsorbed on the chabazite, in which CuO can be formed on the chabazite after calcination at 773 K for two hours. The EXAFS data show that copper in the soil and chabazite possesses Cu-O bond distances of 1.96 and 1.95 Å, respectively and coordination numbers (CNs) of 1-3. After CLC, CuO on chabazite has been reduced to Cu with a C-C bond distance of 2.4 Å and a CN of 8. This work also exemplifies the utilization of EXAFS and XANES to reveal the migration path of copper between a contaminated soil and a molecular sieve and interconversion of Cu-CuO in the CLC process.

  12. Chemical and toxicological testing of composted explosives-contaminating soil

    SciTech Connect

    Griest, W.H.; Steward, A.J.; Tyndall, R.L.; Caton, J.E.; Ho, C.H.; Ironside, K.S.; Caldwell, W.M.; Tan, E. )

    1993-06-01

    Static-pile and mechanically stirred composts of explosives-contaminated soil at the Umatilla Army Depot Activity (UMDA, Umatilla, OR) in a field composting optimization study were characterized chemically and toxicologically. The concentrations of extractable explosives (e.g., 2,4,6-trinitrotoluene) in the composts and their aqueous leachates, the mutagenicity of organic solvent extracts from the composts, and the toxicity of compost aqueous leachates to Ceriodaphnia dubia all decreased considerably with 20 d of composting. After 44 d or 90 d of composting, the toxicity, mutagenicity, and concentrations of extractable explosives decreased more than 90% in some cases. The composting efficiency was generally inversely proportional to the percentage (v/v) of contaminated soil. Composting in static piles was efficient up to about 20% (v/v) of contaminated soil; composting in the mechanically stirred composters was efficient up to about 25% soil. Mechanical composting was more efficient than composting in static piles. The main conclusion of this study is that composting can effectively remediate explosives contaminated soil and sediment. However, low levels of explosives and metabolites, bacterial mutagenicity, and leachable toxicity to Ceriodaphnia may remain after composting. The sources of residual toxicity and mutagenicity and the ultimate fate of the explosives are unknown.

  13. Geochemistry of lead contaminated wetland soils amended with phosphorus

    NASA Astrophysics Data System (ADS)

    Strawn, Daniel G.; Hickey, Patrick; Knudsen, Andrew; Baker, Leslie

    2007-03-01

    To remediate Pb contaminated soils it is proposed that phosphorus can be amended to the soils to transform the Pb into poorly soluble Pb-phosphate mineral phases. However, remediation strategies must account for variable Pb speciation and site-specific factors. In this study soil mineralogy and Pb speciation in soils from P-amended field trials at sites within the Coeur d’Alene River Basin in Idaho, USA were investigated. The soils are contaminated from mining activities and are enriched with Fe and Mn. Selective extraction of the soils indicated that the Fe oxides are poorly crystalline. XRD of the soil clay size fractions identified quartz, muscovite, kaolinite, siderite, lepidocrocite, and chlorite minerals. Amendment with P fertilizer dissolved the siderite. No Pb-phosphate minerals were detected by XRD. Electron microprobe analysis showed direct correlations between Pb, Fe, and Mn in the unamended soils, and negative correlations between Pb and Si. Lead and Mn were strongly correlated. In the amended soils Fe and P were strongly correlated. Results indicate that the Pb is associated with poorly crystalline Fe and Mn oxides, and that added P is primarily associated with Fe oxide phases. Comparisons of pore water Pb concentrations with chloropyromorphite and plumbogummite solubility suggest that in the phosphate-amended soils the pore waters are undersaturated in these phases, whereas several of the control soil pore waters were oversaturated, indicating the added phosphate suppressed the Pb solubility. Results from this research provide insight into the geochemistry occurring in the P-remediated soils that will help in making management and remediation decisions.

  14. Environmental effects of soil contamination by shale fuel oils.

    PubMed

    Kanarbik, Liina; Blinova, Irina; Sihtmäe, Mariliis; Künnis-Beres, Kai; Kahru, Anne

    2014-10-01

    Estonia is currently one of the leading producers of shale oils in the world. Increased production, transportation and use of shale oils entail risks of environmental contamination. This paper studies the behaviour of two shale fuel oils (SFOs)--'VKG D' and 'VKG sweet'--in different soil matrices under natural climatic conditions. Dynamics of SFOs' hydrocarbons (C10-C40), 16 PAHs, and a number of soil heterotrophic bacteria in oil-spiked soils was investigated during the long-term (1 year) outdoor experiment. In parallel, toxicity of aqueous leachates of oil-spiked soils to aquatic organisms (crustaceans Daphnia magna and Thamnocephalus platyurus and marine bacteria Vibrio fischeri) and terrestrial plants (Sinapis alba and Hordeum vulgare) was evaluated. Our data showed that in temperate climate conditions, the degradation of SFOs in the oil-contaminated soils was very slow: after 1 year of treatment, the decrease of total hydrocarbons' content in the soil did not exceed 25 %. In spite of the comparable chemical composition of the two studied SFOs, the VKG sweet posed higher hazard to the environment than the heavier fraction (VKG D) due to its higher mobility in the soil as well as higher toxicity to aquatic and terrestrial species. Our study demonstrated that the correlation between chemical parameters (such as total hydrocarbons or total PAHs) widely used for the evaluation of the soil pollution levels and corresponding toxicity to aquatic and terrestrial organisms was weak. PMID:24865504

  15. Assessment of combined electro-nanoremediation of molinate contaminated soil.

    PubMed

    Gomes, Helena I; Fan, Guangping; Mateus, Eduardo P; Dias-Ferreira, Celia; Ribeiro, Alexandra B

    2014-09-15

    Molinate is a pesticide widely used, both in space and time, for weed control in rice paddies. Due to its water solubility and affinity to organic matter, it is a contaminant of concern in ground and surface waters, soils and sediments. Previous works have showed that molinate can be removed from soils through electrokinetic (EK) remediation. In this work, molinate degradation by zero valent iron nanoparticles (nZVI) was tested in soils for the first time. Soil is a highly complex matrix, and pollutant partitioning between soil and water and its degradation rates in different matrices is quite challenging. A system combining nZVI and EK was also set up in order to study the nanoparticles and molinate transport, as well as molinate degradation. Results showed that molinate could be degraded by nZVI in soils, even though the process is more time demanding and degradation percentages are lower than in an aqueous solution. This shows the importance of testing contaminant degradation, not only in aqueous solutions, but also in the soil-sorbed fraction. It was also found that soil type was the most significant factor influencing iron and molinate transport. The main advantage of the simultaneous use of both methods is the molinate degradation instead of its accumulation in the catholyte. PMID:24946031

  16. In situ recycling of contaminated soil uses bioremediation

    SciTech Connect

    Shevlin, P.J.; Reel, D.A.

    1996-04-01

    OxyChem Pipeline Operations, primarily an ethylene and propylene products mover, has determined that substantial savings can be realized by adopting a bioremediation maintenance and recycling approach to hydrocarbon-contaminated soil. By this method, the soil can be recycled in situ, or in containers. To implement the soil-recycling program, OxyChem elected to use a soil remediator and natural absorbent product, Oil Snapper. This field maintenance material, based on an Enhanced Urea Technology, provides a diet to stimulate the growth of hydrocarbon-eating microbes. It works well either with indigenous soil microbes or with commercial microbes. The product is carried in field vehicles, which makes it immediately available when leaks or spills are discovered. Procedure for clean-up is to apply product and mix it into affected soil. Thus the contaminant is contained, preventing further migration; the contaminant is dispersed throughout the product, making it more accessible to the microbes; nutrients are immediately available to the microbes; and the material contributes aeration and moisture-retention properties.

  17. Application of Ultrasonic for Decontamination of Contaminated Soil - 13142

    SciTech Connect

    Vasilyev, A.P.; Lebedev, N.M.; Savkin, A.E.

    2013-07-01

    The trials of soil decontamination were carried out with the help of a pilot ultrasonic installation in different modes. The installation included a decontamination bath equipped with ultrasonic sources, a precipitator for solution purification from small particles (less than 80 micrometer), sorption filter for solution purification from radionuclides washing out from soil, a tank for decontamination solution, a pump for decontamination solution supply. The trials were carried out on artificially contaminated sand with specific activity of 4.5 10{sup 5} Bk/kg and really contaminated soil from Russian Scientific Center 'Kurchatovsky Institute' (RSC'KI') with specific activity of 2.9 10{sup 4} Bk/kg. It was established that application of ultrasonic intensify the process of soil reagent decontamination and increase its efficiency. The decontamination factor for the artificially contaminated soil was ∼200 and for soil from RSC'KI' ∼30. The flow-sheet diagram has been developed for the new installation as well as determined the main technological characteristics of the equipment. (authors)

  18. Remediation of Contaminated Soils By Supercritical Carbon Dioxide Extraction

    NASA Astrophysics Data System (ADS)

    Ferri, A.; Zanetti, M. C.; Banchero, M.; Fiore, S.; Manna, L.

    The contaminants that can be found in soils are many, inorganic, like heavy metals, as well as organic. Among the organic contaminants, oil and coal refineries are responsi- ble for several cases of soil contamination with PAHs (Polycyclic Aromatic Hydrocar- bons). Polynuclear aromatic hydrocarbons (PAHs) have toxic, carcinogenic and mu- tagenic effects. Limits have been set on the concentration of most contaminants, and growing concern is focusing on soil contamination issues. USA regulations set the maximum acceptable level of contamination by PAHs equal to 40 ppm at residential sites and 270 ppm at industrial sites. Stricter values are usually adopted in European Countries. Supercritical carbon dioxide extraction is a possible alternative technology to remove volatile organic compounds from contaminated soils. Supercritical fluid extraction (SFE) offers many advantages over conventional solvent extraction. Super- critical fluids combine gaseous properties as a high diffusion coefficient, and liquid properties as a high solvent power. The solvent power is strongly pressure-dependent near supercritical conditions: selective extractions are possible without changing the solvent. Solute can be separate from the solvent depressurising the system; therefore, it is possible to recycle the solvent and recover the contaminant. Carbon dioxide is frequently used as supercritical fluid, because it has moderate critical conditions, it is inert and available in pure form. In this work, supercritical fluid extraction technology has been used to remove a polynuclear aromatic hydrocarbon from contaminated soils. The contaminant choice for the experiment has been naphthalene since several data are available in literature. G. A. Montero et al. [1] studied soil remediation with supercrit- ical carbon dioxide extraction technology; these Authors have found that there was a mass-transfer limitation. In the extraction vessel, the mass transfer coefficient in- creases with the

  19. Recycling Ni from Contaminated and Mineralized Soils.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rare plant species accumulate potentially valuable concentrations of some metals. Alyssum murale readily accumulates over 2% Ni in aboveground dry matter when grown on Ni-mineralized serpentine soils in Oregon, allowing production of “hay” biomass with at least 400 kg Ni ha-1 with low levels of fer...

  20. Transport of agricultural contaminants through karst soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Karst landscapes are common in many agricultural regions in the US. Well-developed karst landscapes are characterized by shallow soils, sinkholes, sinking streams, underground conduits, and springs. In these landscapes surface runoff is minimal and most recharge enters the subsurface relatively quic...

  1. DEMONSTRATION BULLETIN: HYDRAULIC FRACTURING OF CONTAMINATED SOIL

    EPA Science Inventory

    Hydraulic fracturing is a physical process that creates fractures in silty clay soil to enhance its permeability. The technology, developed by the Risk Reduction Engineering Laboratory (RREL) and the University of Cincinnati, creates sand-filled horizontal fractures up to 1 in. i...

  2. Electrokinetic remediation of fluorine-contaminated soil and its impact on soil fertility.

    PubMed

    Zhou, Ming; Wang, Hui; Zhu, Shufa; Liu, Yana; Xu, Jingming

    2015-11-01

    Compared to soil pollution by heavy metals and organic pollutants, soil pollution by fluorides is usually ignored in China. Actually, fluorine-contaminated soil has an unfavorable influence on human, animals, plants, and surrounding environment. This study reports on electrokinetic remediation of fluorine-contaminated soil and the effects of this remediation technology on soil fertility. Experimental results showed that electrokinetic remediation using NaOH as the anolyte was a considerable choice to eliminate fluorine in contaminated soils. Under the experimental conditions, the removal efficiency of fluorine by the electrokinetic remediation method was 70.35%. However, the electrokinetic remediation had a significant impact on the distribution and concentrations of soil native compounds. After the electrokinetic experiment, in the treated soil, the average value of available nitrogen was raised from 69.53 to 74.23 mg/kg, the average value of available phosphorus and potassium were reduced from 20.05 to 10.39 mg/kg and from 61.31 to 51.58 mg/kg, respectively. Meanwhile, the contents of soil available nitrogen and phosphorus in the anode regions were higher than those in the cathode regions, but the distribution of soil available potassium was just the opposite. In soil organic matter, there was no significant change. These experiment results suggested that some steps should be taken to offset the impacts, after electrokinetic treatment. PMID:26109225

  3. Biological attributes of rehabilitated soils contaminated with heavy metals.

    PubMed

    Valentim Dos Santos, Jessé; Varón-López, Maryeimy; Fonsêca Sousa Soares, Cláudio Roberto; Lopes Leal, Patrícia; Siqueira, José Oswaldo; de Souza Moreira, Fatima Maria

    2016-04-01

    This study aimed to evaluate the effects of two rehabilitation systems in sites contaminated by Zn, Cu, Pb, and Cd on biological soil attributes [microbial biomass carbon (Cmic), basal and induced respiration, enzymatic activities, microorganism plate count, and bacterial and fungal community diversity and structure by denaturing gradient gel electrophoresis (DGGE)]. These systems (S1 and S2) consisted of excavation (trenching) and replacement of contaminated soil by uncontaminated soil in rows with Eucalyptus camaldulensis planting (S1-R and S2-R), free of understory vegetation (S1-BR), or completely covered by Brachiaria decumbens (S2-BR) in between rows. A contaminated, non-rehabilitated (NR) site and two contamination-free sites [Cerrado (C) and pasture (P)] were used as controls. Cmic, densities of bacteria and actinobacteria, and enzymatic activities (β-glucosidase, acid phosphatase, and urease) were significantly higher in the rehabilitated sites of system 2 (S2-R and S2-BR). However, even under high heavy metal contents (S1-R), the rehabilitation with eucalyptus was also effective. DGGE analysis revealed similarity in the diversity and structure of bacteria and fungi communities between rehabilitated sites and C site (uncontaminated). Principal component analysis showed clustering of rehabilitated sites (S2-R and S2-BR) with contamination-free sites, and S1-R was intermediate between the most and least contaminated sites, demonstrating that the soil replacement and revegetation improved the biological condition of the soil. The attributes that most explained these clustering were bacterial density, acid phosphatase, β-glucosidase, fungal and actinobacterial densities, Cmic, and induced respiration. PMID:26662102

  4. Assessing Metal Contamination in Lead Arsenate Contaminated Orchard Soils Using Near and Mid-Infrared Diffuse Reflectance Spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Historic use of lead-arsenate as pesticide in apple orchards left many soils contaminated with arsenic (As) and lead (Pb). Notorious health effects and their severe soil contamination are of primary concerns for major regulatory agencies, and community at large. Wet chemistry methods for soil anal...

  5. Phytoremediation: using green plants to clean up contaminate soil, groundwater, and wastewater

    SciTech Connect

    Negri, M.C.; Hinchman, R.R.; Gatliff, E.G.

    1996-07-01

    Phytoremediation, an emerging cleanup technology for contaminated soils, groundwater, and wastewater that is both low-tech and low-cost, is defined as the engineered use of green plants (including grasses, forbs, and woody species) to remove, contain, or render harmless such environmental contaminants as heavy metals, trace elements, organic compounds and radioactive compounds in soil or water. Our research includes a successful field demonstration of a plant bioreactor for processing the salty wastewater from petroleum wells; the demonstration is currently under way at a natural gas well site in Oklahoma, in cooperation with Devon Energy Corporation. A greenhouse experiment on zinc uptake in hybrid poplar (Populus sp.) was initiated in 1995. These experiments are being conducted to confirm and extend field data indicating high levels of zinc (4,200 ppm) in leaves of hybrid poplar growing as a cleanup system at a site with zinc contamination in the root zone of some of the trees. Analyses of soil water from experimental pots that had received several doses of zinc indicated that the zinc was totally sequestered by the plants in about 4 hours during a single pass through the root system. The data also showed concentrations of sequestered metal of >38,000 ppm Zn in the dry root tissue. These levels of sequestered zinc exceed the levels found in either roots or tops of many of the known ``hyperaccumulator`` species. Because the roots sequester most of the contaminant taken up in most plants, a major objective of this program is to determine the feasibility of root harvesting as a method to maximize the removal of contaminants from soils. Available techniques and equipment for harvesting plant roots, including young tree roots, are being evaluated and modified as necessary for use with phytoremediation plants.

  6. Dispersal of radioactivity by wildlife from contaminated sites in a forested landscape

    SciTech Connect

    Garten Jr, Charles T

    1995-12-01

    Oak Ridge National Laboratory (ORNL) is located within the Valley and Ridge Physiographic Province of eastern Tennessee (USA). Wildlife populations have access to some radioactively contaminated sites at ORNL. Contaminated animals or animal nests within the Laboratory's boundaries have been found to contain {sup 90}Sr or {sup 137}Cs on the order of 10{sup -2}-10{sup 4} Bqg{sup -1} and trace amounts of other radionuclides (including transuranic elements). Animals that are capable of flight and animals with behavior patterns or developmental life stages involving contact with sediments in radioactive ponds, like benthic invertebrates, present the greatest potential for dispersal of radioactivity. The emigration of frogs and turtles from waste ponds also presents a potential for dispersal of radioactivity but over distances < 5 km. Mud-dauber wasps (Hymenoptera) and swallows (Hirundinidae) may transport radioactive mud for nest building, but also over relatively short distances (0.2-1 km). Movement by small mammals is limited by several factors, including physical barriers and smaller home ranges. Larger animals, like white-tailed deer (Odocoileus virginianus), are potential vectors of radioactivity due to their greater body size, longer life expectancy, and larger home range. Larger animals contain greater amounts of total radioactivity than smaller animals, but tissue concentrations of {sup 137}Cs generally decline with body size.

  7. Phytoremediation of contaminated soils and groundwater: lessons from the field

    SciTech Connect

    Vangronsveld, J.; van der Lelie, D.; Herzig, R.; Weyens, N.; Boulet, J.; Adriaensen, K.; Ruttens, A.; Thewys, T.; Vassilev, A.; Meers, E.; Nehnevajova, E.; Mench, M.

    2009-11-01

    The use of plants and associated microorganisms to remove, contain, inactivate, or degrade harmful environmental contaminants (generally termed phytoremediation) and to revitalize contaminated sites is gaining more and more attention. In this review, prerequisites for a successful remediation will be discussed. The performance of phytoremediation as an environmental remediation technology indeed depends on several factors including the extent of soil contamination, the availability and accessibility of contaminants for rhizosphere microorganisms and uptake into roots (bioavailability), and the ability of the plant and its associated microorganisms to intercept, absorb, accumulate, and/or degrade the contaminants. The main aim is to provide an overview of existing field experience in Europe concerning the use of plants and their associated microorganisms whether or not combined with amendments for the revitalization or remediation of contaminated soils and undeep groundwater. Contaminations with trace elements (except radionuclides) and organics will be considered. Because remediation with transgenic organisms is largely untested in the field, this topic is not covered in this review. Brief attention will be paid to the economical aspects, use, and processing of the biomass. It is clear that in spite of a growing public and commercial interest and the success of several pilot studies and field scale applications more fundamental research still is needed to better exploit the metabolic diversity of the plants themselves, but also to better understand the complex interactions between contaminants, soil, plant roots, and microorganisms (bacteria and mycorrhiza) in the rhizosphere. Further, more data are still needed to quantify the underlying economics, as a support for public acceptance and last but not least to convince policy makers and stakeholders (who are not very familiar with such techniques).

  8. Heavy-metal contamination of soils in Saxony/Germany by foundry fumes and low-cost rapid analyses of contaminated soils by XRF

    NASA Astrophysics Data System (ADS)

    Mucke, D.

    2012-04-01

    spectrometry (XRF) with a handheld instrument. Approx. 40 elements hereby are determined in a focussed X-ray spot of 3 mm of diameters. The device can be put directly on a section of the soil or measure loose substrata in a PVC bag through or in a cuvette. The measurement time is 30 seconds. In connection with the input of information, the relocating and the sample preparation 20 measurings can be carried out per hour. This leads at personnel expenditures of € 50/hour at a price of € 2.50/analysis of simultaneous 40 components. At requirement the transfer of the files from the instrument in Excel tables still would rise expenses. XRF is a fast low-cost method for the first assessment of the contamination of soils and the delimitation of areas of different contaminations. When exact laboratory analyses are still requested, the interesting areas from which bulk samples have to be taken for the laboratory examinations, with XRF can be fixed. The contamination with arsenic and toxic heavy metals is only subordinated by modern flue gas treatment in metallurgical plants and renunciation of thermal methods with hut smoke today. The whereabouts of arsenic and lead in the soil shows, though, that the soil has protected the groundwater against the contamination. GEOMONTAN has examined the Saxonian areas with radioactive fallout of the Chernobyl accident in the order of the BGR Hannover 1993. In the results of the analysis by BGR Cs-134 was already disintegrated and Cs-137 only 13 cm deep in the uppermost soil layers infiltrated during the 8 years after the accident. This means that soil protects groundwater against contaminations out of the air too. In the last years some German federal state governments decided the end of mine water winning for the public water supply and deregulated the water protection zones. The water supply was converted in water of water supply dams. The hazard of contamination of this open reservoirs by accidents or terrorism is increasing. Underground water

  9. Sediment transfer in coastal catchments exposed to typhoons: lessons learnt from catchments contaminated with Fukushima radioactive fallout

    NASA Astrophysics Data System (ADS)

    Evrard, Olivier; Laceby, J. Patrick; Onda, Yuichi; Lefèvre, Irène

    2016-04-01

    Several coastal catchments located in Northeastern Japan received significant radioactive fallout following the Fukushima nuclear accident in March 2011, with initial 137Cs activities exceeding 100 kBq m-2. Although radiocesium poses a considerable health risk for local populations, it also provides a relatively straightforward tracer to investigate sediment transfers in catchments exposed to spring floods and heavy typhoons in late summer and early fall. This study focused on two catchments (the Niida and Mano Rivers) covering a surface area of 450 km² that drain the main radioactive plume. A database of radiocesium activities measured in potential source samples (n=260) was used to model radiocesium dilution in 342 sediment deposit samples collected at 38 locations during 9 different sampling campaigns conducted every 6 months from Nov. 2011 to Nov. 2015. The dilution of the initial radiocesium contamination in sediment was individually calculated for each of the 342 samples using a distribution model. Results show that the proportion of heavily contaminated sediment increased from 27% to 39% after the occurrence of typhoons in 2013 (with rainfall amount exceeding 100 mm in 48 hours) and from 29% to 45% after the 2015 spring floods, illustrating the occurrence of soil erosion and resuspension of contaminated material stored in the river channel. In contrast, the occurrence of a very strong typhoon in September 2015 (up to 450 mm in 48h) led to the dilution and the flush of the contamination to the Pacific Ocean, with the proportion of heavily contaminated material decreasing from 45 to 21%. This case study in catchments impacted by the Fukushima accident illustrates their high reactivity to both human activities and rainfall. These results will improve our understanding of sediment transfers in similar coastal mountainous environments frequently exposed to heavy rainfall.

  10. Electrokinetic treatment of an agricultural soil contaminated with heavy metals.

    PubMed

    Figueroa, Arylein; Cameselle, Claudio; Gouveia, Susana; Hansen, Henrik K

    2016-07-28

    The high organic matter content in agricultural soils tends to complex and retain contaminants such as heavy metals. Electrokinetic remediation was tested in an agricultural soil contaminated with Co(+2), Zn(+2), Cd(+2), Cu(+2), Cr(VI), Pb(+2) and Hg(+2). The unenhanced electrokinetic treatment was not able to remove heavy metals from the soil due to the formation of precipitates in the alkaline environment in the soil section close to the cathode. Moreover, the interaction between metals and organic matter probably limited metal transportation under the effect of the electric field. Citric acid and ethylenediaminetetraacetic acid (EDTA) were used in the catholyte as complexing agents in order to enhance the extractability and removal of heavy metals from soil. These complexing agents formed negatively charged complexes that migrated towards the anode. The acid front electrogenerated at the anode favored the dissolution of heavy metals that were transported towards the cathode. The combined effect of the soil pH and the complexing agents resulted in the accumulation of heavy metals in the center of the soil specimen. PMID:27127923

  11. Deep soil mixing for reagent delivery and contaminant treatment

    SciTech Connect

    Korte, N.; Gardner, F.G.; Cline, S.R.; West, O.R.

    1997-12-31

    Deep soil mixing was evaluated for treating clay soils contaminated with TCE and its byproducts at the Department of Energy`s Kansas City Plant. The objective of the project was to evaluate the extent of limitations posed by the stiff, silty-clay soil. Three treatment approaches were tested. The first was vapor stripping. In contrast to previous work, however, laboratory treatability studies indicated that mixing saturated, clay soil was not efficient unless powdered lime was added. Thus, powder injection of lime was attempted in conjunction with the mixing/stripping operation. In separate treatment cells, potassium permanganate solution was mixed with the soil as a means of destroying contaminants in situ. Finally, microbial treatment was studied in a third treatment zone. The clay soil caused operational problems such as breakage of the shroud seal and frequent reagent blowouts. Nevertheless, treatment efficiencies of more than 70% were achieved in the saturated zone with chemical oxidation. Although expensive ($1128/yd{sup 3}), there are few alternatives for soils of this type.

  12. Tool samples subsurface soil free of surface contaminants

    NASA Technical Reports Server (NTRS)

    Kemmerer, W. W.; Wooley, B. C.

    1967-01-01

    Sampling device obtains pure subsurface soil that is free of any foreign substance that may exist on the surface. It is introduced through a contaminated surface area in a closed condition, opened, and a subsurface sample collected, sealed while in the subsurface position, and then withdrawn.

  13. USING PLANTS TO REMEDIATE PETROLEUM-CONTAMINATED SOIL: PROJECT CONTINUATION

    EPA Science Inventory

    Crude oil contamination of soil often occurs adjacent to wellheads and storage facilities. Phytoremediation is a promising tool that can be used to remediate such sites and uses plants and agronomic techniques to enhance biodegradation of hydrocarbons. This project has conduct...

  14. SUPERFUND ENGINEERING ISSUE: TREATMENT OF LEAD-CONTAMINATED SOILS

    EPA Science Inventory

    This document summarizes the contents of a seminar on treatment of lead-contaminated soils presented on August 28, 1990, to Region V Superfund and RCRA personnel by members of EPA's Engineering and Treatment Technology Support Center located in the Risk Reduction Engineering Labo...

  15. HANDBOOK ON IN SITU TREATMENT OF HAZARDOUS WASTE- CONTAMINATED SOILS

    EPA Science Inventory

    This handbook comprises an update of Volume1 of the 1984 USEPA document entitled "Review of In-Place Treatment Techniques for Contaminated Surface Soils." The purpose of this handbook is the same as that of the original document - to provide state-of-the-art information on in sit...

  16. DERMAL ABSORPTION OF CONTAMINANTS FROM SEDIMENTS/SOILS

    EPA Science Inventory

    The mechanisms by which contaminants are released from sediments/soils and absorbed into the skin are poorly understood. The project will first conduct invitro experiments to study the effects of particle layering and chemical saturation. Secondly, mechanistic models will be de...

  17. LINKING WATERFOWL WITH CONTAMINANT SPECIATION IN RIPARIAN SOILS

    EPA Science Inventory

    This report summarizes the results of Mine Waste Technology Program (MWTP) Activity III, Project 38, Linking Waterfowl with Contaminant Speciation in Riparian Soils, implemented and funded by the U.S. Environmental Protection Agency (EPA) and jointly administered by EPA and the U...

  18. AN ESTIMATE OF SOILS CONTAMINATED WITH SECONDARY EXPLOSIVES

    EPA Science Inventory

    This report provides the results of a study that examined the quantities of explosives-contaminated soils at Army installations in the United States in order to understand the user requirements for environmental technology research and development work. This report provides a tim...

  19. APPLICATION, PERFORMANCE, AND COSTS OF BIOTREATMENT TECHNOLOGIES FOR CONTAMINATED SOILS

    EPA Science Inventory

    A critical review of biological treatment processes for remediation of contaminated soils is presented. The focus of the review is on documented cost and performance of biological treatment technologies demonstrated at full- or
    field-scale. Some of the data were generated b...

  20. SUMMARY PAPER: IN SITU BIOREMEDIATION OF CONTAMINATED VADOSE ZONE SOIL

    EPA Science Inventory

    The Robert S. Kerr Environmental Research Laboratory (RSKERL) has developed a number of Issue Papers and Briefing Documents which are designed to exchange up-to-date information related to the remediation of contaminated soil and ground water at hazardous waste sites. In an attem...

  1. MUTAGENICITY OF PAH-CONTAMINATED SOILS DURING BIOREMEDIATION

    EPA Science Inventory

    Bioremediation of contaminated soils is considered an effective method for reducing potential health hazards. Although it is assumed that (bio)remediation is a detoxifying process, degradation products of compounds such as polycyclic aromatic compounds (PACs) can be more toxic th...

  2. Chemical methods and phytoremediation of soil contaminated with heavy metals.

    PubMed

    Chen, H M; Zheng, C R; Tu, C; Shen, Z G

    2000-07-01

    The effects of chemical amendments (calcium carbonate (CC), steel sludge (SS) and furnace slag (FS)) on the growth and uptake of cadmium (Cd) by wetland rice, Chinese cabbage and wheat grown in a red soil contaminated with Cd were investigated using a pot experiment. The phytoremediation of heavy metal contaminated soil with vetiver grass was also studied in a field plot experiment. Results showed that treatments with CC, SS and FS decreased Cd uptake by wetland rice, Chinese cabbage and wheat by 23-95% compared with the unamended control. Among the three amendments, FS was the most efficient at suppressing Cd uptake by the plants, probably due to its higher content of available silicon (Si). The concentrations of zinc (Zn), lead (Pb) and Cd in the shoots of vetiver grass were 42-67%, 500-1200% and 120-260% higher in contaminated plots than in control, respectively. Cadmium accumulation by vetiver shoots was 218 g Cd/ha at a soil Cd concentration of 0.33 mg Cd/kg. It is suggested that heavy metal-contaminated soil could be remediated with a combination of chemical treatments and plants. PMID:10819205

  3. Antimony release from contaminated mine soils and its migration in four typical soils using lysimeter experiments.

    PubMed

    Shangguan, Yu-Xian; Zhao, Long; Qin, Yusheng; Hou, Hong; Zhang, Naiming

    2016-11-01

    Antimony (Sb) can pose great risks to the environment in mining and smelting areas. The migration of Sb in contaminated mine soil was studied using lysimeter experiments. The exchangeable concentration of soil Sb decreased with artificial leaching. The concentrations of Sb retained in the subsoil layers (5-25cm deep) were the highest for Isohumosol and Ferrosol and the lowest for Sandy soil. The Sb concentrations in soil solutions decreased with soil depth, and were adequately simulated using a logarithmic function. The Sb migration pattern in Sandy soil was markedly different from the patterns in the other soils which suggested that Sb may be transported in soil colloids. Environmental factors such as water content, soil temperature, and oxidation-reduction potential of the soil had different effects on Sb migration in Sandy soil and Primosol. The high Fe and Mn contents in Ferrosol and Isohumosol significantly decreased the mobility of Sb in these soils. The Na and Sb concentrations in soils used in the experiments positively correlated with each other (P<0.01). The Sb concentrations in soil solutions, the Sb chemical fraction patterns, and the Sb/Na ratios decreased in the order Sandy soil>Primosol>Isohumosol>Ferrosol, and we concluded that the Sb mobility in the soils also decreased in that order. PMID:27395817

  4. Multiscale structure of Cs-137 soil contamination on the Bryansk Region (Russia) due to the accident at the Chernobyl NPP

    NASA Astrophysics Data System (ADS)

    Linnik, Vitaly; Sokolov, Alexander

    2013-04-01

    The Cs-137 contamination of the Bryansk Region occurred in the period from April 27 to May 10 into several stages. The complicated character of the soil radionuclide contamination on the Bryansk Region is caused by different nature of the radioactive fallout: dry and wet. Thus, in a number of cases Cs-137 soil pollution is directly connected with the rain intensity, which is well known, have multifractal nature. In some parts of contaminated territory the overlay of different types of fallout was observed. The radioactive contamination of the landscape is a result from nonlinear interplay of geophysical factors which intervene over a large range of scale. As a result of the fallout Cs-137 pattern can be described as a multifractal. Consequently, fields of contamination observed have an extreme spatial variability, frequently cited "hot spots" or "leopard's skin. As an estimate of background radiation levels, we relied on a dataset of air-gamma-survey of the Bryansk Region, carried out by SSC AEROGEOFIZIKA in the summer of 1993. This dataset includes geo-positioned data of Cs-137 deposition in a grid of 100x100 m with values range from 3 to 11*104 kBq/m2. Airborne gamma survey gave the smoothed values of the Cs-137 density of contamination in comparison with the data, obtained directly as a result of soil sampling. However, even in this case in the east part of the Bryansk test site we can observed the"hot spots" (by size several hundred meters) as natural phenomenon. The article presents the results of the geostatistical and multifractal analysis of the Cs-137 contamination. Scaling analysis was conducted to investigate the linkages between the spatial variability of soil Cs-137 contamination and some landscape characteristics.

  5. Renewed soil erosion and remobilisation of radioactive sediment in Fukushima coastal rivers after the 2013 typhoons

    PubMed Central

    Evrard, Olivier; Chartin, Caroline; Onda, Yuichi; Lepage, Hugo; Cerdan, Olivier; Lefèvre, Irène; Ayrault, Sophie

    2014-01-01

    Summer typhoons and spring snowmelt led to the riverine spread of continental Fukushima fallout to the coastal plains of Northeastern Japan and the Pacific Ocean. Four fieldwork campaigns based on measurement of radioactive dose rates in fine riverine sediment that has recently deposited on channel bed-sand were conducted between November 2011 and May 2013 to document the spread of fallout by rivers. After a progressive decrease in the fresh riverine sediment doses rates between 2011 and early spring in 2013, a fifth campaign conducted in November 2013 showed that they started to increase again after the occurrence of violent typhoons. We show that this increase in dose rates was mostly due to remobilization of contaminated material that was temporarily stored in river channels or, more importantly, in dam reservoirs of the region during the typhoons. In addition, supply of particles from freshly eroded soils in autumn 2013 was the most important in areas where decontamination works are under progress. Our results underline the need to monitor the impact of decontamination works and dam releases in the region, as they may provide a continuous source of radioactive contamination to the coastal plains and the Pacific Ocean during the coming years. PMID:24694549

  6. Sources and remediation techniques for mercury contaminated soil.

    PubMed

    Xu, Jingying; Bravo, Andrea Garcia; Lagerkvist, Anders; Bertilsson, Stefan; Sjöblom, Rolf; Kumpiene, Jurate

    2015-01-01

    Mercury (Hg) in soils has increased by a factor of 3 to 10 in recent times mainly due to combustion of fossil fuels combined with long-range atmospheric transport processes. Other sources as chlor-alkali plants, gold mining and cement production can also be significant, at least locally. This paper summarizes the natural and anthropogenic sources that have contributed to the increase of Hg concentration in soil and reviews major remediation techniques and their applications to control soil Hg contamination. The focus is on soil washing, stabilisation/solidification, thermal treatment and biological techniques; but also the factors that influence Hg mobilisation in soil and therefore are crucial for evaluating and optimizing remediation techniques are discussed. Further research on bioremediation is encouraged and future study should focus on the implementation of different remediation techniques under field conditions. PMID:25454219

  7. Electrokinetic In Situ Treatment of Metal-Contaminated Soil

    NASA Technical Reports Server (NTRS)

    Quinn, Jacqueline; Clausen, Christian A., III; Geiger, Cherie; Reinhart, Debra

    2004-01-01

    An electrokinetic technique has been developed as a means of in situ remediation of soils, sludges, and sediments that are contaminated with heavy metals. Examples of common metal contaminants that can be removed by this technique include cadmium, chromium, zinc, lead, mercury, and radionuclides. Some organic contaminants can also be removed by this technique. In the electrokinetic technique, a low-intensity direct current is applied between electrodes that have been implanted in the ground on each side of a contaminated soil mass. The electric current causes electro-osmosis and migration of ions, thereby moving aqueous-phase subsurface contaminants from one electrode to the other. The half reaction at the anode yields H+, thereby generating an acid front that travels from the anode toward the cathode. As this acid front passes through a given location, the local increase in acidity increases the solubility of cations that were previously adsorbed on soil particles. Ions are transported towards one electrode or the other which one depending on their respective electric charges. Upon arrival at the electrodes, the ionic contaminants can be allowed to become deposited on the electrodes or can be extracted to a recovery system. Surfactants and other reagents can be introduced at the electrodes to enhance rates of removal of contaminants. Placements of electrodes and concentrations and rates of pumping of reagents can be adjusted to maximize efficiency. The basic concept of electrokinetic treatment of soil is not new. What is new here are some of the details of application and the utilization of this technique as an alternative to other techniques (e.g., flushing or bioremediation) that are not suitable for treating soils of low hydraulic conductivity. Another novel aspect is the use of this technique as a less expensive alternative to excavation: The cost advantage over excavation is especially large in settings in which contaminated soil lies near and/or under

  8. Phytoremediation of Metal-Contaminated Soil for Improving Food Safety

    NASA Astrophysics Data System (ADS)

    Shilev, Stefan; Benlloch, Manuel; Dios-Palomares, R.; Sancho, Enrique D.

    The contamination of the environment is a serious problem which provokes great interest in our society and in the whole scientific community. The input of metals into soils has increased during the last few decades as a consequence of different human activities (storage of industrial and municipal wastes, burning of fuels, mining and wastewater treatments, functioning of non-ferrous-metal-producing smelters, etc.). Nowadays, this type of contamination is one of the most serious concerning the chronic toxic effect which it renders on human health and the environment. As a consequence of all these activities, a huge number of toxic metals and metalloids, such as Cu, Zn, Pb, Cd, Hg and As, among many others, have been accumulated in soils, reaching toxic values. Unfortunately, much contaminated land is still in use for crop production, despite the danger that the metal content poses.

  9. Chemical fingerprinting of hydrocarbon-contamination in soil.

    PubMed

    Boll, Esther S; Nejrup, Jens; Jensen, Julie K; Christensen, Jan H

    2015-03-01

    Chemical fingerprinting analyses of 29 hydrocarbon-contaminated soils were performed to assess the soil quality and determine the main contaminant sources. The results were compared to an assessment based on concentrations of the 16 priority polycyclic aromatic hydrocarbons pointed out by the U.S. Environmental Protection Agency (EPAPAH16) and total petroleum hydrocarbon (TPH). The chemical fingerprinting strategy proposed in this study included four tiers: (i) qualitative analysis of GC-FID chromatograms, (ii) comparison of the chemical composition of both un-substituted and alkyl-substituted polycyclic aromatic compounds (PACs), (iii) diagnostic ratios of selected PACs, and (iv) multivariate data analysis of sum-normalized PAC concentrations. The assessment criteria included quantitative analysis of 19 PACs and C1-C4 alkyl-substituted homologues of naphthalene, fluorene, dibenzothiophene, phenanthrene, pyrene, and chrysene; and 13 oxygenated polycyclic aromatic compounds (O-PACs). The chemical composition of un-substituted and alkyl-substituted PACs and visual interpretation of GC-FID chromatograms were in combination successful in differentiating pyrogenic and petrogenic hydrocarbon sources and in assessing weathering trends of hydrocarbon contamination in the soils. Multivariate data analysis of sum-normalized concentrations could as a stand-alone tool distinguish between hydrocarbon sources of petrogenic and pyrogenic origin, differentiate within petrogenic sources, and detect weathering trends. Diagnostic ratios of PACs were not successful for source identification of the heavily weathered hydrocarbon sources in the soils. The fingerprinting of contaminated soils revealed an underestimation of PACs in petrogenic contaminated soils when the assessment was based solely on EPAPAH16. As alkyl-substituted PACs are dominant in petrogenic sources, the evaluation of the total load of PACs based on EPAPAH16 was not representative. Likewise, the O-PACs are not

  10. Changes in the structure and function of soil ecosystems in soils contaminated with heavy metals

    SciTech Connect

    Kuperman, R.; Parmelee, R.; Carreiro, M. ||

    1995-06-01

    The structure and function of soil communities in an area with a wide range of concentrations of heavy metals was studied in portions of the U.S. Army`s Aberdeen Proving Ground, Maryland. The study included survey of soil macro- and microinvertebrate communities, soil microorganisms, enzyme activities and the rates of nutrient dynamics in soil. Soil macroinvertebrate communities showed significant reductions in the abundance of several taxonomic and functional groups in contaminated areas. The total numbers of nematodes and numbers of fungivore, bacterivore and omnivore-predator nematodes were lower in the more contaminated areas. The numbers of active bacteria and fungi were lower in areas of soil contamination. Significant reduction in the activities of all enzymes closely paralleled the increase in heavy metal concentrations. Ten-to-fifty fold reductions in enzyme activities were observed as heavy metal concentrations increased. These results suggest that soil contamination with heavy metals may have detrimental effects on soil biota and the rates of organic matter degradation and subsequent release of nutrients to aboveground communities in the area.

  11. Changes in the structure and function of soil ecosystems in soils contaminated with heavy metals

    SciTech Connect

    Kuperman, R.; Parmelee, R.; Carreiro, M. ||

    1995-09-01

    The structure and function of soil communities in an area with a wide range of concentrations of heavy metals was studied in portions of the U.S. Army`s Aberdeen Proving Ground, Maryland. The study included survey of soil macro- and microinvertebrate communities, soil microorganisms, enzyme activities and the rates of nutrient dynamics in soil. Soil macroinvertebrate communities showed significant reductions in the adundance of several taxonomic and functional groups in contaminated areas. The total numbers of nematodes and numbers of fungivore, bacterivore and omnivore-predator nematodes were lower in the more contaminated areas. The numbers of active bacteria and fungi were lower in areas of soil contamination. Significant reduction in the activities of all enzymes closely paralleled the increase in heavy metal concentrations. Ten-to-fifty fold reductions in enzyme activities were observed as heavy metal concentrations increased. These results suggest that soil contamination with heavy metals may have detrimental effects on soil biota and the rates of organic matter degradation and subsequent release of nutrients to aboveground communities in the area.

  12. EFFECT OF SOIL MODIFYING FACTORS ON THE BIOAVAILABILITY AND TOXICITY OF METAL CONTAMINATED SOILS

    EPA Science Inventory

    Heavy metal and organic chemical contamination of soils is a worldwide problem posing a risk to humans and more directly, soil organisms. Metal toxicity is often not directly related to the total concentration of metals present due to a number of modifying factors that depend,...

  13. Interactive effects of Cd and PAHs on contaminants removal from co-contaminated soil planted with hyperaccumulator plant Sedum alfredii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil contamination by multiple organic and inorganic contaminants is common but its remediation by hyperaccumulator plants is rarely reported. The growth of a cadmium (Cd) hyperaccumulator Sedum alfredii and removal of contaminants from Cd and polycyclic aromatic hydrocarbons(PAHs) co-contaminated s...

  14. [Bio-remediation techniques of crude oil contaminated soils].

    PubMed

    Li, Peijun; Guo, Shuhai; Sun, Tieheng; Tai, Peidong; Zhang, Chungui; Bai, Yuxing; Sun, Qiang; Sheng, Ping

    2002-11-01

    The bioremediation of soils contaminated by different types of petroleum were carried out with composting process in a prepared bed. By the measures of nutrient- and microbiological agent addition, and moisture- and pH control, an ideal environment for microbes were obtained. When total petroleum hydrocarbons, which consist of thin oil, high condensation oil, special viscous oil, and viscous oil, were in the range of 25.8-77.2 g.kg-1 dry soil, the petroleum removal rate could reach 38.37-56.74% by 2 months operation. The contents of aromatic hydrocarbon, asphaltum and resin were important factors controlling the degradation of petroleum. 6 fungi, 6 bacteria and 1 actinomyces were found to be the dominant strains for petroleum degradation. The results could provide theoretical bases for remediation of soil contaminated by petroleum. PMID:12625007

  15. Phytoremediation of heavy metal contaminated soil by Jatropha curcas.

    PubMed

    Chang, Fang-Chih; Ko, Chun-Han; Tsai, Ming-Jer; Wang, Ya-Nang; Chung, Chin-Yi

    2014-12-01

    This study employed Jatropha curcas (bioenergy crop plant) to assist in the removal of heavy metals from contaminated field soils. Analyses were conducted on the concentrations of the individual metals in the soil and in the plants, and their differences over the growth periods of the plants were determined. The calculation of plant biomass after 2 years yielded the total amount of each metal that was removed from the soil. In terms of the absorption of heavy metal contaminants by the roots and their transfer to aerial plant parts, Cd, Ni, and Zn exhibited the greatest ease of absorption, whereas Cu, Cr, and Pb interacted strongly with the root cells and remained in the roots of the plants. J. curcas showed the best absorption capability for Cd, Cr, Ni, and Zn. This study pioneered the concept of combining both bioremediation and afforestation by J. curcas, demonstrated at a field scale. PMID:25236867

  16. Electrokinetic treatment of firing ranges containing tungsten-contaminated soils.

    PubMed

    Braida, Washington; Christodoulatos, Christos; Ogundipe, Adebayo; Dermatas, Dimitris; O'Connor, Gregory

    2007-11-19

    Tungsten-based alloys and composites are being used and new formulations are being considered for use in the manufacturing of different types of ammunition. The use of tungsten heavy alloys (WHA) in new munitions systems and tungsten composites in small caliber ammunition could potentially release substantial amounts of this element into the environment. Although tungsten is widely used in industrial and military applications, tungsten's potential environmental and health impacts have not been thoroughly addressed. This necessitates the research and development of remedial technologies to contain and/or remove tungsten from soils that may serve as a source for water contamination. The current work investigates the feasibility of using electrokinetics for the remediation of tungsten-contaminated soils in the presence of other heavy metals of concern such as Cu and Pb with aim to removing W from the soil while stabilizing in situ, Pb and Cu. PMID:17686582

  17. Electrokinetic remediation of six emerging organic contaminants from soil.

    PubMed

    Guedes, Paula; Mateus, Eduardo P; Couto, Nazaré; Rodríguez, Yadira; Ribeiro, Alexandra B

    2014-12-01

    Some organic contaminants can accumulate in organisms and cause irreversible damages in biological systems through direct or indirect toxic effects. In this study the feasibility of the electrokinetic (EK) process for the remediation of 17β-oestradiol (E2), 17α-ethinyloestradiol (EE2), bisphenol A (BPA), nonylphenol (NP), octylphenol (OP) and triclosan (TCS) in soils was studied in a stationary laboratory cell. The experiments were conducted using a silty loam soil (S2) at 0, 10 and 20mA and a sandy soil (S3) at 0 and 10 mA. A pH control in the anolyte reservoir (pH>13) at 10 mA was carried out using S2, too. Photo and electrodegradation experiments were also fulfilled. Results showed that EK is a viable method for the remediation of these contaminants, both through mobilization by electroosmotic flow (EOF) and electrodegradation. As EOF is very sensible to soil pH, the control in the anolyte increased EOF rate, consequently enhancing contaminants mobilization towards the cathode end. The extent of the mobilization towards the electrode end was mainly dependent on compounds solubility and octanol-water partition coefficient. In the last 24h of experiments, BPA presented the highest mobilization rate (ca. 4 μg min(-1)) with NP not being detected in the catholyte. At the end of all experiments the percentage of contaminants that remained in the soil ranged between 17 and 50 for S2, and between 27 and 48 for S3, with no statistical differences between treatments. The mass balance performed showed that the amount of contaminant not detected in the cell is similar to the quantity that potentially may suffer photo and electrodegradation. PMID:24997283

  18. Identifying root exudates in field contaminated soil systems

    NASA Astrophysics Data System (ADS)

    Rosenfeld, C.; Martinez, C. E.

    2012-12-01

    Carbon (C) compounds exuded from plant roots comprise a significant and reactive fraction of belowground C pools. These exudates substantially alter the soil directly surrounding plant roots and play a vital role in the global C cycle, soil ecology, and ecosystem mobility of both nutrients and contaminants. In soils, the solubility and bioavailability of metals such as iron, zinc, and cadmium are intricately linked to the quantity and chemical characteristics of the C compounds allocated to the soil by plants. Cadmium (Cd), a toxic heavy metal, forms stronger bonds with reduced S- and N-containing compounds than with carboxylic acids, which may influence exudate composition in hyperaccumulator and tolerant plants grown in Cd contaminated soils. We hypothesize that hyperaccumulator plants will exude a larger quantity of aromatic N and chelating di- and tri-carboxylic acid molecules, while plants that exclude heavy metals from uptake will exude a larger proportion of reduced S containing molecules. This study examines how a variety of techniques can measure the low concentrations of complex organic mixtures exuded by hyperaccumulator and non-hyperaccumulator plants grown in Cd-contaminated soils. Two congeneric plants, Thlaspi caerulescens (Ganges ecotype), and T. caerulescens (Prayon ecotype) were grown in 0.5 kg pots filled with Cd-contaminated field soils from Chicago, IL. Field soils were contaminated as a result of the application of contaminated biosolids in the 1960's and 1970's. Pots were fitted for rhizon soil moisture samplers, micro-lysimeters developed for in situ collection of small volumes in unsaturated soils, prior to planting. Plants were grown for 8 weeks before exudate collection. After the 8 weeks of growth, a pulse-chase isotope tracer method using the C stable isotope, 13C, was employed to differentiate plant-derived compounds from background soil and microbial-derived compounds. Plants were placed in a CO2 impermeable chamber, and the soil

  19. Assessment of lead bioaccessibility in peri-urban contaminated soils.

    PubMed

    Smith, Euan; Weber, John; Naidu, Ravi; McLaren, Ronald G; Juhasz, Albert L

    2011-02-15

    Lead (Pb) bioaccessibility was assessed in a range of peri-urban soils (n=31) with differing sources of Pb contamination, including shooting range soils, and soils affected by incinerator, historical fill, mining/smelting, and gasworks activities. A gossan soil sample was also included. Lead bioaccessibility was determined using both gastric and intestinal phases of the SBRC in vitro assay and in vitro data was then incorporated into in vivo-in vitro regression equations to calculate Pb relative bioavailability. Lead bioaccessibility ranged from 26.8-105.2% to 5.5-102.6% for gastric and intestinal phase extractions respectively. Generally, Pb bioaccessibility was highest in the shooting range soils and lowest in the gossan soil. Predictions of relative Pb bioavailability derived from in vitro data were comparable for shooting ranges soils, but highly variable for the other soils examined. For incinerator, historical fill, gasworks and gossan soils, incorporating in vitro gastric data into the in vivo-in vitro regression equation resulting in more conservative Pb relative bioavailability values than those derived using the intestinal in vitro data. PMID:21115224

  20. Overcoming phytoremediation limitations. A case study of Hg contaminated soil

    NASA Astrophysics Data System (ADS)

    Barbafieri, Meri

    2013-04-01

    Phytoremediation is a broad term that comprises several technologies to clean up water and soil. Despite the numerous articles appearing in scientific journals, very few field applications of phytoextraction have been successfully realized. The research here reported on Phytoextraction, the use the plant to "extract" metals from contaminated soil, is focused on implementations to overcome two main drawbacks: the survival of plants in unfavorable environmental conditions (contaminant toxicity, low fertility, etc.) and the often lengthy time it takes to reduce contaminants to the requested level. Moreover, to overcome the imbalance between the technology's potential and its drawbacks, there is growing interest in the use of plants to reduce only the fraction that is the most hazardous to the environment and human health, that is to target the bioavailable fractions of metals in soil. Bioavailable Contaminant Stripping (BCS) would be a remediation approach focused to remove the bioavailable metal fractions. BCS have been used in a mercury contaminated soil from Italian industrial site. Bioavailable fractions were determined by sequential extraction with H2O and NH4Cl.Combined treatments of plant hormone and thioligand to strength Hg uptake by crop plants (Brassica juncea and Helianthus annuus) were tested. Plant biomass, evapotranspiration, Hg uptake and distribution following treatments were compared. Results indicate the plant hormone, cytokinine (CK) foliar treatment, increased evapotranspiration rate in both tested plants. The Hg uptake and translocation in both tested plants increased with simultaneous addition of CK and TS treatments. B. juncea was the most effective in Hg uptake. Application of CK to plants grown in TS-treated soil lead to an increase in Hg concentration of 232% in shoots and 39% in roots with respect to control. While H. annuus gave a better response in plant biomass production, the application of CK to plants grown in TS-treated soil lead to

  1. EVALUATION OF SOLIDIFICATION/STABILIZATION AS A BEST DEMONSTRATED AVAILABLE TECHNOLOGY FOR CONTAMINATED SOILS

    EPA Science Inventory

    This project involved the evaluation of solidification/stabilization technology as a BDAT for contaminated soil. Three binding agents were used on four different synthetically contaminated soils. Performance evaluation data included unconfined compressive strength (UCS) and the T...

  2. Assessing the bioavailability and risk from metal-contaminated soils and dusts

    EPA Science Inventory

    Exposure to contaminated soil and dust is an important pathway in human health risk assessment. Physical and chemical characteristics, as well as biological factors, determine the bioaccessibility/bioavailability of soil and dust contaminants. Within a single sample, contaminat...

  3. Heavy-metal contamination of soils in Saxony/Germany by foundry fumes and low-cost rapid analyses of contaminated soils by XRF

    NASA Astrophysics Data System (ADS)

    Mucke, D.

    2012-04-01

    spectrometry (XRF) with a handheld instrument. Approx. 40 elements hereby are determined in a focussed X-ray spot of 3 mm of diameters. The device can be put directly on a section of the soil or measure loose substrata in a PVC bag through or in a cuvette. The measurement time is 30 seconds. In connection with the input of information, the relocating and the sample preparation 20 measurings can be carried out per hour. This leads at personnel expenditures of € 50/hour at a price of € 2.50/analysis of simultaneous 40 components. At requirement the transfer of the files from the instrument in Excel tables still would rise expenses. XRF is a fast low-cost method for the first assessment of the contamination of soils and the delimitation of areas of different contaminations. When exact laboratory analyses are still requested, the interesting areas from which bulk samples have to be taken for the laboratory examinations, with XRF can be fixed. The contamination with arsenic and toxic heavy metals is only subordinated by modern flue gas treatment in metallurgical plants and renunciation of thermal methods with hut smoke today. The whereabouts of arsenic and lead in the soil shows, though, that the soil has protected the groundwater against the contamination. GEOMONTAN has examined the Saxonian areas with radioactive fallout of the Chernobyl accident in the order of the BGR Hannover 1993. In the results of the analysis by BGR Cs-134 was already disintegrated and Cs-137 only 13 cm deep in the uppermost soil layers infiltrated during the 8 years after the accident. This means that soil protects groundwater against contaminations out of the air too. In the last years some German federal state governments decided the end of mine water winning for the public water supply and deregulated the water protection zones. The water supply was converted in water of water supply dams. The hazard of contamination of this open reservoirs by accidents or terrorism is increasing. Underground water

  4. Enhancing agents for phytoremediation of soil contaminated by cyanophos.

    PubMed

    Ali Romeh, Ahmed

    2015-07-01

    Cyanophos is commonly used in Egypt to control various agricultural and horticultural pests. It is a strong contaminant in the crop culturing environments because it is highly persistent and accumulates in the soil. This contaminant can be removed by phytoremediation, which is the use of plants to clean-up pollutants. Here we tested several several strategies to improve the effectiveness of this technology, which involved various techniques to solubilize contaminants. The phytoremediation efficiency of Plantago major L. was improved more by liquid silicon dioxide (SiO₂) than by other solubility-enhancing agents, resulting in the removal of significant amounts of cyanophos from contaminated soil. Liquid SiO₂ increased the capacity of P. major L. to remove cyanophos from soil by 45.9% to 74.05%. In P. major L. with liquid SiO₂, leaves extracted more cyanophos (32.99 µg/g) than roots (13.33 µg/g) over 3 days. The use of solubilization agents such as surfactants, hydroxypropyl-ß-cyclodextrin (HPßCD), natural humic acid acid (HA), and Tween 80 resulted in the removal of 60 convergents of cyanophos from polluted soil. Although a batch equilibrium technique showed that use of HPßCD resulted in the efficient removal of cyanophos from soil, a greater amount of cyanophos was removed by P. major L. with SiO₂. Moreover, a large amount of cyanophos was removed from soil by rice bran. This study indicates that SiO₂ can improve the efficiency of phytoremediation of cyanophos. PMID:25847752

  5. Derivation of guidelines for uranium residual radioactive material in soil at the Colonie Site, Colonie, New York

    SciTech Connect

    Dunning, D.

    1996-05-01

    Residual radioactive material guidelines for uranium in soil were derived for the Colonie site located in Colonie, New York. This site has been designated for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the U.S. Department of Energy (DOE). The site became contaminated with radioactive material as a result of operations conducted by National Lead (NL) Industries from 1958 to 1984; these activities included brass foundry operations, electroplating of metal products, machining of various components using depleted uranium, and limited work with small amounts of enriched uranium and thorium. The Colonie site comprises the former NL Industries property, now designated the Colonie Interim Storage Site (CISS), and 56 vicinity properties contaminated by fallout from airborne emissions; 53 of the vicinity properties were previously remediated between 1984 and 1988. In 1984, DOE accepted ownership of the CISS property from NL Industries. Residual radioactive material guidelines for individual radionuclides and total uranium were derived on the basis of the requirement that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works in the immediate vicinity of the site should not exceed a dose of 30 mrem/yr following remedial action for the current use and likely future use scenarios or a dose of 100 mrem/yr for less likely future use scenarios. The DOE residual radioactive material guideline computer code, RESRAD, was used in this evaluation; RESRAD implements the methodology described in the DOE manual for establishing residual radioactive material guidelines.

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

    NASA Astrophysics Data System (ADS)

    Lepage, H.; Evrard, O.; Onda, Y.; Chartin, C.; Lefevre, I.; Sophie, A.; Bonte, P.

    2015-03-01

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

  7. FINAL REPORT: REAL-TIME IDENTIFICATION AND CHARACTERIZATION OF ASBESTOS AND CONCRETE MATERIALS WITH RADIOACTIVE CONTAMINATION

    EPA Science Inventory

    Concrete and asbestos-containing materials were widely used in DOE building construction in the 1940s and 1950s. Over the years, many of these porous materials have been contaminated with radioactive sources, on and below the surface. To improve current practice in identifying ha...

  8. REAL-TIME IDENTIFICATION AND CHARACTERIZATION OF ASBESTOS AND CONCRETE MATERIALS WITH RADIOACTIVE CONTAMINATION

    EPA Science Inventory

    Concrete and asbestos-containing materials were widely used in DOE building construction in the 1940s and 1950s. Over the years, many of these porous materials have been contaminated with radioactive sources, on and below the surface. Current practice to identify hazardous asbe...

  9. REAL-TIME IDENTIFICATION AND CHARACTERIZATION OF ASBESTOS AND CONCRETE MATERIALS WITH RADIOACTIVE CONTAMINATION

    SciTech Connect

    XU, X. George; Zhang, X.C.

    2002-05-10

    Concrete and asbestos-containing materials were widely used in DOE building construction in the 1940s and 1950s. Over the years, many of these porous materials have been contaminated with radioactive sources, on and below the surface. To improve current practice in identifying hazardous materials and in characterizing radioactive contamination, an interdisciplinary team from Rensselaer has conducted research in two aspects: (1) to develop terahertz time-domain spectroscopy and imaging system that can be used to analyze environmental samples such as asbestos in the field, and (2) to develop algorithms for characterizing the radioactive contamination depth profiles in real-time in the field using gamma spectroscopy. The basic research focused on the following: (1) mechanism of generating of broadband pulsed radiation in terahertz region, (2) optimal free-space electro-optic sampling for asbestos, (3) absorption and transmission mechanisms of asbestos in THz region, (4) the role of asbestos sample conditions on the temporal and spectral distributions, (5) real-time identification and mapping of asbestos using THz imaging, (7) Monte Carlo modeling of distributed contamination from diffusion of radioactive materials into porous concrete and asbestos materials, (8) development of unfolding algorithms for gamma spectroscopy, and (9) portable and integrated spectroscopy systems for field testing in DOE. Final results of the project show that the combination of these innovative approaches has the potential to bring significant improvement in future risk reduction and cost/time saving in DOE's D and D activities.

  10. Multicomponent and multistep radioactive decay modeling module for groundwater flow and contaminant transport computer code

    NASA Astrophysics Data System (ADS)

    Kharkhordin, I. L.

    2013-12-01

    Correct calculations of multistep radioactive decay is important for radionuclide transport forecast at contaminated sites and designing radionuclide storage facilities as well as for a number applications of natural radioactive tracers for understanding of groundwater flow in complex hydrogeological systems. Radioactive chains can involves a number of branches with certain probabilities of decay and up to fourteen steps. General description of radioactive decay in complex system could be presented as a system of linear differential equations. Numerical solution of this system encounters a difficulties connected with wide rage of radioactive decay constants variations. In present work the database with 1253 records of radioactive isotope decay parameters for 97 elements was created. An algorithm of analytical solution construction and solving was elaborated for arbitrary radioactive isotope system taking into account the possible chain branching and connection. The algorithm is based on radionuclide decay graphs. The main steps of algorithm is as follows: a) searching of all possible isotopes in database, creation full isotope list; b) looking for main parent isotopes; c) construction of all possible radioactive chains; d) looking for branching and connections in decay chains, marking of links as primary (left chain in graph for main parent isotope), secondary (after connection), and recurring (before branching); e) construction and calculation the coefficients for analytical solutions. The developed computer code was tested on a few simple systems like follows: Cs-135 - one step decay, Sr-90 (Y-90) - two steps decay, U-238+U-235 mixture - complex decay with branching. Calculation of radiogenic He-4 is also possible witch could be important application for groundwater flow and transport model calibration using natural tracers. The computer code for multistep radioactive calculation was elaborated for incorporation into NIMFA code. NIMFA is a parallel computer code

  11. Ecotoxicity of a polycyclic aromatic hydrocarbon (PAH)-contaminated soil.

    PubMed

    Eom, I C; Rast, C; Veber, A M; Vasseur, P

    2007-06-01

    Soil samples from a former cokery site polluted with polycyclic aromatic hydrocarbons (PAHs) were assessed for their toxicity to terrestrial and aquatic organisms and for their mutagenicity. The total concentration of the 16 PAHs listed as priority pollutants by the US Environmental Protection Agency (US-EPA) was 2634+/-241 mg/kgdw in soil samples. The toxicity of water-extractable pollutants from the contaminated soil samples was evaluated using acute (Vibrio fischeri; Microtox test, Daphnia magna) and chronic (Pseudokirchneriella subcapitata, Ceriodaphnia dubia) bioassays and the EC values were expressed as percentage water extract in the test media (v/v). Algal growth (EC50-3d=2.4+/-0.2% of the water extracts) and reproduction of C. dubia (EC50-7d=4.3+/-0.6%) were the most severely affected, compared to bacterial luminescence (EC50-30 min=12+/-3%) and daphnid viability (EC50-48 h=30+/-3%). The Ames and Mutatox tests indicated mutagenicity of water extracts, while no response was found with the umu test. The toxicity of the soil samples was assessed on the survival and reproduction of earthworms (Eisenia fetida) and collembolae (Folsomia candida), and on the germination and growth of higher plants (Lactuca sativa L.: lettuce and Brassica chinensis J.: Chinese cabbage). The EC50 values were expressed as percentage contaminated soil in ISO soil test medium (weight per weight-w/w) and indicated severe effects on reproduction of the collembola F. candida (EC50-28 d=5.7%) and the earthworm E. fetida (EC50-28 d=18% and EC50-56 d=8%, based on cocoon and juvenile production, respectively). Survival of collembolae was already affected at a low concentration of the contaminated soil (EC50-28 d=11%). The viability of juvenile earthworms was inhibited at much lower concentrations of the cokery soil (EC50-14 d=28%) than the viability of adults (EC50-14 d=74%). Only plant growth was inhibited (EC50-17d=26%) while germination was not. Chemical analyses of water extracts allowed

  12. Evaluation of soil flushing of complex contaminated soil: an experimental and modeling simulation study.

    PubMed

    Yun, Sung Mi; Kang, Christina S; Kim, Jonghwa; Kim, Han S

    2015-04-28

    The removal of heavy metals (Zn and Pb) and heavy petroleum oils (HPOs) from a soil with complex contamination was examined by soil flushing. Desorption and transport behaviors of the complex contaminants were assessed by batch and continuous flow reactor experiments and through modeling simulations. Flushing a one-dimensional flow column packed with complex contaminated soil sequentially with citric acid then a surfactant resulted in the removal of 85.6% of Zn, 62% of Pb, and 31.6% of HPO. The desorption distribution coefficients, KUbatch and KLbatch, converged to constant values as Ce increased. An equilibrium model (ADR) and nonequilibrium models (TSNE and TRNE) were used to predict the desorption and transport of complex contaminants. The nonequilibrium models demonstrated better fits with the experimental values obtained from the column test than the equilibrium model. The ranges of KUbatch and KLbatch were very close to those of KUfit and KLfit determined from model simulations. The parameters (R, β, ω, α, and f) determined from model simulations were useful for characterizing the transport of contaminants within the soil matrix. The results of this study provide useful information for the operational parameters of the flushing process for soils with complex contamination. PMID:25698434

  13. Sand amendment enhances bioelectrochemical remediation of petroleum hydrocarbon contaminated soil.

    PubMed

    Li, Xiaojing; Wang, Xin; Ren, Zhiyong Jason; Zhang, Yueyong; Li, Nan; Zhou, Qixing

    2015-12-01

    Bioelectrochemical system is an emerging technology for the remediation of soils contaminated by petroleum hydrocarbons. However, performance of such systems can be limited by the inefficient mass transport in soil. Here we report a new method of sand amendment, which significantly increases both oxygen and proton transports, resulting to increased soil porosity (from 44.5% to 51.3%), decreased Ohmic resistance (by 46%), and increased charge output (from 2.5 to 3.5Cg(-1)soil). The degradation rates of petroleum hydrocarbons increased by up to 268% in 135d. The degradation of n-alkanes and polycyclic aromatic hydrocarbons with high molecular weight was accelerated, and denaturing gradient gel electrophoresis showed that the microbial community close to the air-cathode was substantially stimulated by the induced current, especially the hydrocarbon degrading bacteria Alcanivorax. The bioelectrochemical stimulation imposed a selective pressure on the microbial community of anodes, including that far from the cathode. These results suggested that sand amendment can be an effective approach for soil conditioning that will enhances the bioelectrochemical removal of hydrocarbons in contaminated soils. PMID:26135976

  14. Cytotoxic and genotoxic potential of tannery waste contaminated soils.

    PubMed

    Masood, Farhana; Malik, Abdul

    2013-02-01

    Soil samples from agricultural fields in the vicinity of industrial area of Jajmau, Kanpur (India) were collected and found to be heavily contaminated with various toxic heavy metals. GC-MS analysis revealed the presence of organic compounds mainly phthalates in contaminated soils. Samples were extracted using dichloromethane (DCM) and hexane solvents, and the extracts were assayed for genotoxic potential using three different bioassays namely Ames Salmonella/mammalian microsome test, DNA repair defective Escherichia coli K-12 mutants and Allium cepa chromosomal aberration assay. TA98 was found to be the most sensitive strain to all the soil extracts tested. The highest mutagenic potential was observed in DCM extracts of soil as compared with hexane extracts for each strain of Salmonella typhimurium. DCM extracts of the soil exhibited maximum damage to the cells at a dose of 40 μl of soil extracts/ml of culture after a 6-h treatment. The survival was 23% in polA, 40% in lexA and 53% in recA mutants when treated with DCM extract of site I. In A. cepa assay, all the test concentrations of soil extracts (5-100%) affected mitotic index in a dose-dependent manner and several types of abnormalities were observed at different mitotic stages with the treatments: C-mitosis, anaphase bridges, laggards, binucleated cells, stickiness, broken and unequal distributions of chromosomes at anaphase stage of cell division. The soil is accumulating a large number of pollutants as a result of wastewater irrigation and this practice of accumulation has an adverse impact on soil health. PMID:23268142

  15. [Mixture Leaching Remediation Technology of Arsenic Contaminated Soil].

    PubMed

    Chen, Xun-feng; Li, Xiao-ming; Chen, Can; Yang, Qi; Deng, Lin-jing; Xie, Wei-qiang; Zhong, Yui; Huang, Bin; Yang, Wei-qiang; Zhang, Zhi-bei

    2016-03-15

    Soil contamination of arsenic pollution has become a severely environmental issue, while soil leaching is an efficient method for remediation of arsenic-contaminated soil. In this study, batch tests were primarily conducted to select optimal mixture leaching combination. Firstly, five conventional reagents were selected and combined with each other. Secondly, the fractions were analyzed before and after the tests. Finally, to explore the feasibility of mixed leaching, three soils with different arsenic pollution levels were used to compare the leaching effect. Comparing with one-step washing, the two-step sequential washing with different reagents increased the arsenic removal efficiency. These results showed that the mixture of 4 h 0.5 mol · L⁻¹ NaOH + 4 h 0.1 mol · L⁻¹ EDTA was found to be practicable, which could enhance the removal rate of arsenic from 66.67% to 91.83%, and the concentration of arsenic in soil was decreased from 186 mg · kg⁻¹ to 15.2 mg · kg⁻¹. Furthermore, the results indicated that the distribution of fractions of arsenic in soil changed apparently after mixture leaching. Leaching process could significantly reduce the available contents of arsenic in soil. Moreover, the mixture of 0.5 mol · L⁻¹ NaOH + 0.1 mol L⁻¹ EDTA could well decrease the arsenic concentration in aluminum-type soils, while the mixture of 0.5 mol · L⁻¹ OX + 0.5 mol · L⁻¹ NaOH could well decrease the arsenic concentration in iron-type soils. PMID:27337912

  16. Analysis of disposition alternatives for radioactively contaminated scrap metal

    SciTech Connect

    Nieves, L.A.; Chen, S.Y.; Kohout, E.J.; Nabelssi, B.; Tilbrook, R.W.; Wilson, S.E.

    1997-01-01

    Millions of tonnes of slightly radioactive, scrap iron and steel, stainless steel, and copper are likely to become available as nuclear and other facilities and equipment are withdrawn from service. Disposition of this material is an international policy issue under consideration currently. The major alternatives for managing this material are to either develop a regulatory process for decontamination and recycling that will safeguard human health or to dispose of the scrap and replace the metal stocks. To evaluate the alternatives, we estimate quantities of scrap arising from nuclear power plant decommissioning, evaluate potential price impacts of recycling on regional markets, and assess the health and environmental impacts of the management alternatives. We conclude that decontaminating and recycling the scrap is the superior alternative.

  17. Research Spotlight: Potential pathways of radioactive contaminants to surface waters

    NASA Astrophysics Data System (ADS)

    Kumar, Mohi

    2011-02-01

    From the 1940s to the end of the Cold War, the U.S. Department of Energy maintained production facilities for manufacturing nuclear weapons along the Columbia River north of Richland, Wash. Known as the Hanford Site, the Rhode Island-sized area contains more than 53 million gallons of radioactive waste and is the location of a massive environmental cleanup. Of particular concern is that when the facility was active, fluids containing 33-59 tons of uranium were discharged into the shallow subsurface aquifer underneath Hanford. Studies suggest that this pollution is pervasively moving with the groundwater in the direction of the Columbia River. (Water Resources Research, doi:10.1029/2010WR009110, 2010)

  18. On the analytic estimation of radioactive contamination from degraded alphas

    NASA Astrophysics Data System (ADS)

    Kadel, R. W.

    2016-03-01

    The high energy spectrum of alpha particles emitted from a single isotope uniformly contaminating a bulk solid has a flat energy spectrum with a high end cutoff energy equal to the maximal alpha kinetic energy (Tα) of the decay. In this flat region of the spectrum, we show the surface rate rb (Bq keV-1cm-2) arising from a bulk alpha contamination ρb (Bq cm-3) from a single isotope is given by rb =ρb Δ R/ 4 Δ E , where Δ E = E1-E2>0 is the energy interval considered (keV) in the flat region of the spectrum and Δ R = R2-R1, where R2 (R1) is the amount of the bulk material (cm) necessary to degrade the energy of the alpha from Tα to E2 (E1). We compare our calculation to a rate measurement of alphas from 147Sm, (15.32 ± 0.03% of Sm(nat) and half life of (1.06 ± 0.01)× 1011 yr [1]), and find good agreement, with the ratio between prediction to measurement of 100.2%± 1.6% (stat)± 2.1% (sys). We derive the condition for the flat spectrum, and also calculate the relationship between the decay rate measured at the surface for a [near] surface contamination with an exponential dependence on depth and a second case of an alpha source with a thin overcoat. While there is excellent agreement between our implementation of the sophisticated Monte Carlo program SRIM [2] and our intuitive model in all cases, both fail to describe the measured energy distribution of a 148Gd alpha source with a thin (~200μg cm-2) Au overcoat. We discuss possible origins of the disagreement and suggest avenues for future study.

  19. Chelant extraction of heavy metals from contaminated soils.

    PubMed

    Peters, R W

    1999-04-23

    The current state of the art regarding the use of chelating agents to extract heavy metal contaminants has been addressed. Results are presented for treatability studies conducted as worst-case and representative soils from Aberdeen Proving Ground's J-Field for extraction of copper (Cu), lead (Pb), and zinc (Zn). The particle size distribution characteristics of the soils determined from hydrometer tests are approximately 60% sand, 30% silt, and 10% clay. Sequential extractions were performed on the 'as-received' soils (worst case and representative) to determine the speciation of the metal forms. The technique speciates the heavy metal distribution into an easily extractable (exchangeable) form, carbonates, reducible oxides, organically-bound, and residual forms. The results indicated that most of the metals are in forms that are amenable to soil washing (i.e. exchangeable+carbonate+reducible oxides). The metals Cu, Pb, Zn, and Cr have greater than 70% of their distribution in forms amenable to soil washing techniques, while Cd, Mn, and Fe are somewhat less amenable to soil washing using chelant extraction. However, the concentrations of Cd and Mn are low in the contaminated soil. From the batch chelant extraction studies, ethylenediaminetetraacetic acid (EDTA), citric acid, and nitrilotriacetic acid (NTA) were all effective in removing copper, lead, and zinc from the J-Field soils. Due to NTA being a Class II carcinogen, it is not recommended for use in remediating contaminated soils. EDTA and citric acid appear to offer the greatest potential as chelating agents to use in soil washing the Aberdeen Proving Ground soils. The other chelating agents studied (gluconate, oxalate, Citranox, ammonium acetate, and phosphoric acid, along with pH-adjusted water) were generally ineffective in mobilizing the heavy metals from the soils. The chelant solution removes the heavy metals (Cd, Cu, Pb, Zn, Fe, Cr, As, and Hg) simultaneously. Using a multiple-stage batch extraction

  20. The effect of soil type on the bioremediation of petroleum contaminated soils.

    PubMed

    Haghollahi, Ali; Fazaelipoor, Mohammad Hassan; Schaffie, Mahin

    2016-09-15

    In this research the bioremediation of four different types of contaminated soils was monitored as a function of time and moisture content. The soils were categorized as sandy soil containing 100% sand (type I), clay soil containing more than 95% clay (type II), coarse grained soil containing 68% gravel and 32% sand (type III), and coarse grained with high clay content containing 40% gravel, 20% sand, and 40% clay (type IV). The initially clean soils were contaminated with gasoil to the concentration of 100 g/kg, and left on the floor for the evaporation of light hydrocarbons. A full factorial experimental design with soil type (four levels), and moisture content (10 and 20%) as the factors was employed. The soils were inoculated with petroleum degrading microorganisms. Soil samples were taken on days 90, 180, and 270, and the residual total petroleum hydrocarbon (TPH) was extracted using soxhlet apparatus. The moisture content of the soils was kept almost constant during the process by intermittent addition of water. The results showed that the efficiency of bioremediation was affected significantly by the soil type (Pvalue < 0.05). The removal percentage was the highest (70%) for the sandy soil with the initial TPH content of 69.62 g/kg, and the lowest for the clay soil (23.5%) with the initial TPH content of 69.70 g/kg. The effect of moisture content on bioremediation was not statistically significant for the investigated levels. The removal percentage in the clay soil was improved to 57% (within a month) in a separate experiment by more frequent mixing of the soil, indicating low availability of oxygen as a reason for low degradation of hydrocarbons in the clay soil. PMID:27233045

  1. Final report: survey and removal of radioactive surface contamination at environmental restoration sites, Sandia National Laboratories/New Mexico. Volume 1

    SciTech Connect

    Lambert, K.A.; Mitchell, M.M.; Jean, D.; Byrd, C.S.

    1997-09-01

    This report describes the survey and removal of radioactive surface contamination at Sandia`s Environmental Restoration (ER) sites. Radiological characterization was performed as a prerequisite to beginning the Resource Conservation and Recovery Act (RCRA) corrective action process. The removal of radioactive surface contamination was performed in order to reduce potential impacts to human health and the environment. The predominant radiological contaminant of concern was depleted uranium (DU). Between October 1993 and November 1996 scanning surface radiation surveys, using gamma scintillometers, were conducted at 65 sites covering approximately 908 acres. A total of 9,518 radiation anomalies were detected at 38 sites. Cleanup activities were conducted between October 1994 and November 1996. A total of 9,122 anomalies were removed and 2,072 waste drums were generated. The majority of anomalies not removed were associated with a site that has subsurface contamination beyond the scope of this project. Verification soil samples (1,008 total samples) were collected from anomalies during cleanup activities and confirm that the soil concentration achieved in the field were far below the target cleanup level of 230 pCi/g of U-238 (the primary constituent of DU) in the soil. Cleanup was completed at 21 sites and no further radiological action is required. Seventeen sites were not completed since cleanup activities wee precluded by ongoing site activity or were beyond the original project scope.

  2. Electrokinetic treatment of contaminated soils, sludges, and lagoons. Final report

    SciTech Connect

    Wittle, J.K.; Pamukcu, S.

    1993-04-01

    The electrokinetic process is an emerging technology for in-situ soil decontamination, in which chemical species, both ionic and nonionic are transported to an electrode site in soil. These products are subsequently removed from the ground via collection systems engineered for each specific application. Electrokinetics refer to movement of water, ions and charged particles relative to one another under the action of an applied direct current electric field. In a porous compact matrix of surface charged particles such as soil, the ion containing pore fluid may be made to flow to collection sites under the applied field. This report describes the effort undertaken to investigate electrokinetically enhanced transport of soil contaminants in synthetic systems. These systems consisted of clay or clay-sand mixtures containing known concentration of a selected heavy metal salt solution or an organic compound. Metals, surrogate radio nuclides and organic compounds evaluated in the program were representatives of those found at a majority of DOE sites. Degree of removal of these metals from soil by the electrokinetic treatment process was assessed through the metal concentration profiles generated across the soil between the electrodes. The best removals, from about 85 to 95% were achieved at the anode side of the soil specimens. Transient pH change had an effect on the metal movement via transient creation of different metal species with different ionic mobilities, as well as changing of the surface characteristics of the soil medium.

  3. Subchronic exposure of mice to Love Canal soil contaminants

    SciTech Connect

    Silkworth, J.B.; McMartin, D.N.; Rej, R.; Narang, R.S.; Stein, V.B.; Briggs, R.G.; Kaminsky, L.S.

    1984-04-01

    The health hazard potential of soil collected from the surface of the Love Canal chemical dump site in Niagara Falls, New York, was assessed in 90-day exposure studies. Female CD-1 mice were exposed to two concentrations of the volatile components of 1 kg of soil with and without direct soil contact. Control mice were identically housed but without soil. The soil was replaced weekly and 87 compounds were detected in the air in the cages above fresh and 7-day-old soil as analyzed by gas chromatography/mass spectrometry. The concentration of many of these compounds decreased during the 7-day exposure cycle. Histopathologic, hematologic, and serum enzyme studies followed necropsy of all mice. There was no mortality of mice exposed for up to 90 days under any condition. Thymus and spleen weights relative to body weight were increased after 4 weeks of exposure by inhalation but not after 8 or 12 weeks of exposure. alpha-, beta-, and delta- Benzenehexachlorides , pentachlorobenzene, and hexachlorobenzene were detected in liver tissue from these animals. Mice exposed to 5- to 10-fold elevated concentration of volatiles had increased body and relative kidney weights. There was no chemically induced lesion in any animal exposed only to the volatile soil contaminants. Mice exposed by direct contact with the soil without elevated volatile exposure had increased body (10%) and relative liver weights (169%). Centrolobular hepatocyte hypertrophy, which involved 40 to 70% of the lobules, was observed in all mice in this group.

  4. Investigating the control of mercury volatilization from contaminated soil

    NASA Astrophysics Data System (ADS)

    Steffy, D. A.; Nichols, A.

    2009-12-01

    In previous investigations of growing earthworms, Lumbricus terrestris, in contaminated soil, we have found that volatilization of mercury (Hg) to be an active process. The question to be answered is what causes the reduction of Hg to a more volatile state in the soil, could it be the earthworms? A series of laboratory tests were conducted to determine the mechanism of Hg reduction. The tests revealed that earthworms bioaccumulate the Hg in their tissue, but do not aid in the reduction process. Microbial reduction of the Hg appears to be the mechanism. Two dissimilar soil types were tested; both were heated for 96 hours at 100oC. After cooling, both soil types were spiked with 100 mg of Hg per Kg of soil. Integrated Hg vapor samples were collected immediately above the soil surface over a 3 day period and analyzed by cold vapor atomic adsorption. After heat treatment both soil types had a statistically significantly higher rate of volatilization than unheated soils. We interpret this result as indicating that heating preferentially selected microbial spores that facilitated the Hg reduction.

  5. Relationship between the {sup 137}Cs whole-body counting results and soil and food contamination in farms near Chernobyl

    SciTech Connect

    Takatsuji, Toshihiro; Sato, Hitoshi; Takada, Jun

    2000-01-01

    The authors measured the radioactivity in the soil and child food samples from farms near Mogilev (56--270 GBq km{sup {minus}2} {sup 137}Cs), Gomel (36--810 GBq km{sup {minus}2} {sup 137}Cs), and Klincy (59--270 GBq km{sup {minus}2} {sup 137}Cs), who had whole-body {sup 137}Cs counting results measured as part of a health examination in the Chernobyl Sasakawa Health and Medical Cooperation Project. Soil contamination on the family farm seems to be the main source of human contamination because most of the people in the area live on small farms and they and their domestic animals eat crops from the farms. A clear correlation was found between the children's whole-body {sup 137}Cs counting results and the radioactivity in their food (correlation coefficient: 0.76; confidence level of correlation: 3.2 x 10{sup {minus}9}). There were also significant correlations between the whole-body {sup 137}Cs counting results and both the radioactivity of the soil samples (correlation coefficient: 0.22; confidence level of correlation: 0.0107) and the average contamination level of their current residence (correlation coefficient: 0.20; confidence level of correlation: 0.0174).

  6. Effects of past copper contamination and soil structure on copper leaching from soil.

    PubMed

    Paradelo, Marcos; Moldrup, Per; Arthur, Emmanuel; Naveed, Muhammad; Holmstrup, Martin; López-Periago, Jose E; de Jonge, Lis W

    2013-11-01

    Copper contamination affects biological, chemical, and physical soil properties and associated ecological functions. Changes in soil pore organization as a result of Cu contamination can dramatically affect flow and contaminant transport in polluted soils. This study assessed the influence of soil structure on the movement of water and Cu in a long-term polluted soil. Undisturbed soil cores collected along a Cu gradient (from about 20 to about 3800 mg Cu kg soil) were scanned using X-ray computed tomography (CT). Leaching experiments were performed to analyze tracer transport, colloid leaching, and dissolved organic carbon (DOC) and Cu losses. The 5% arrival time () and apparent dispersivity (λ) for tracer breakthrough were calculated by fitting the experimental data to a nonparametric, double-lognormal probability density function. Soil bulk density, which did not follow the Cu gradient, was the main driver of preferential flow, while macroporosity determined by X-ray CT (for pores >180 μm) proved the best predictor of solute transport. Higher preferential flow due to the presence of well-aligned pores and small cracks controlled water movement in compacted soil. Transport of Cu was rapid during the first flush (≈1 pore volume) in association with the movement of colloid particles, followed by slower transport in association with the movement of DOC in the soil solution. The relative amount of Cu released was strongly correlated with macroporosity as determined by X-ray CT, indicating the promising potential of this visualization technique for predicting contaminant transport through soil. PMID:25602425

  7. Electroremediation of PCB contaminated soil combined with iron nanoparticles: Effect of the soil type.

    PubMed

    Gomes, Helena I; Dias-Ferreira, Celia; Ottosen, Lisbeth M; Ribeiro, Alexandra B

    2015-07-01

    Polychlorinated biphenyls (PCB) are carcinogenic and persistent organic pollutants that accumulate in soils and sediments. Currently, there is no cost-effective and sustainable remediation technology for these contaminants. In this work, a new combination of electrodialytic remediation and zero valent iron particles in a two-compartment cell is tested and compared to a more conventional combination of electrokinetic remediation and nZVI in a three-compartment cell. In the new two-compartment cell, the soil is suspended and stirred simultaneously with the addition of zero valent iron nanoparticles. Remediation experiments are made with two different historically PCB contaminated soils, which differ in both soil composition and contamination source. Soil 1 is a mix of soils with spills of transformer oils, while Soil 2 is a superficial soil from a decommissioned school where PCB were used as windows sealants. Saponin, a natural surfactant, was also tested to increase the PCB desorption from soils and enhance dechlorination. Remediation of Soil 1 (with highest pH, carbonate content, organic matter and PCB concentrations) obtained the maximum 83% and 60% PCB removal with the two-compartment and the three-compartment cell, respectively. The highest removal with Soil 2 were 58% and 45%, in the two-compartment and the three-compartment cell, respectively, in the experiments without direct current. The pH of the soil suspension in the two-compartment treatment appears to be a determining factor for the PCB dechlorination, and this cell allowed a uniform distribution of the nanoparticles in the soil, while there was iron accumulation in the injection reservoir in the three-compartment cell. PMID:25841071

  8. Dispersal of radioactivity by wildlife from contaminated sites in a forested landscape

    SciTech Connect

    Garten, C.T. Jr.

    1992-03-27

    Oak Ridge National Laboratory (ORNL) is located within the Ridge and Valley physiographic province of eastern Tennessee (USA). This area is characterized by deciduous forests dominated by hardwood and mixed mesophytic tree species. Wildlife populations have access to some radioactively contaminated sites at ORNL, and contaminated animals or animal nests within the Laboratory's boundaries have been found to contain on the order of 10{sup {minus}12} to 10{sup {minus}6} Ci/g of {sup 90}Sr or {sup 137}Cs, and trace amounts of other radionuclides (including transuranic elements). Theoretical calculations indicate that nanocurie levels of {sup 90}Sr in bone can arise from relatively small amounts (1%) of contaminated browse vegetation in a deer's diet. Measures that have been undertaken at ORNL to curtail the dispersal of radioactivity by animals are briefly reviewed.

  9. Two dimensional imaging of radiation accidents and radioactive contamination

    NASA Astrophysics Data System (ADS)

    Ogawa, Tomoya; Sarukura, Nobuhiko; Watanabe, Masahito; Fukuda, Tsuguo; Nango, Nobuhito

    2010-05-01

    An accident in a nuclear power plant caused by an unpredictable event such as an explosion, fire and earthquake is so serious that we have to carefully and precisely detect any radiation leakage from the plants, given that the number of nuclear power plants is recently increasing in order to cope with the contamination of air due to carbon dioxide emission from conventional power plants. Invisible radiation contamination of the environment due to nuclear fallout in nuclear power plants and research laboratories is also a very serious problem necessitating an urgent solution. For this purpose, bundles composed of well-designed and regularly arranged scintillation fiber segments or thin cylinders have been developed to detect and display the radiation sources as a map, using the directional sensitivity of the segments or cylinders for locating sources of incident radiation. By combining several types of scintillating elements into a bundle, we have developed a "panchromatic" detector that is suitable for use against radiation from different types of sources.

  10. Emerging Environmental Justice Issues in Nuclear Power and Radioactive Contamination

    PubMed Central

    Kyne, Dean; Bolin, Bob

    2016-01-01

    Nuclear hazards, linked to both U.S. weapons programs and civilian nuclear power, pose substantial environment justice issues. Nuclear power plant (NPP) reactors produce low-level ionizing radiation, high level nuclear waste, and are subject to catastrophic contamination events. Justice concerns include plant locations and the large potentially exposed populations, as well as issues in siting, nuclear safety, and barriers to public participation. Other justice issues relate to extensive contamination in the U.S. nuclear weapons complex, and the mining and processing industries that have supported it. To approach the topic, first we discuss distributional justice issues of NPP sites in the U.S. and related procedural injustices in siting, operation, and emergency preparedness. Then we discuss justice concerns involving the U.S. nuclear weapons complex and the ways that uranium mining, processing, and weapons development have affected those living downwind, including a substantial American Indian population. Next we examine the problem of high-level nuclear waste and the risk implications of the lack of secure long-term storage. The handling and deposition of toxic nuclear wastes pose new transgenerational justice issues of unprecedented duration, in comparison to any other industry. Finally, we discuss the persistent risks of nuclear technologies and renewable energy alternatives. PMID:27420080

  11. Emerging Environmental Justice Issues in Nuclear Power and Radioactive Contamination.

    PubMed

    Kyne, Dean; Bolin, Bob

    2016-01-01

    Nuclear hazards, linked to both U.S. weapons programs and civilian nuclear power, pose substantial environment justice issues. Nuclear power plant (NPP) reactors produce low-level ionizing radiation, high level nuclear waste, and are subject to catastrophic contamination events. Justice concerns include plant locations and the large potentially exposed populations, as well as issues in siting, nuclear safety, and barriers to public participation. Other justice issues relate to extensive contamination in the U.S. nuclear weapons complex, and the mining and processing industries that have supported it. To approach the topic, first we discuss distributional justice issues of NPP sites in the U.S. and related procedural injustices in siting, operation, and emergency preparedness. Then we discuss justice concerns involving the U.S. nuclear weapons complex and the ways that uranium mining, processing, and weapons development have affected those living downwind, including a substantial American Indian population. Next we examine the problem of high-level nuclear waste and the risk implications of the lack of secure long-term storage. The handling and deposition of toxic nuclear wastes pose new transgenerational justice issues of unprecedented duration, in comparison to any other industry. Finally, we discuss the persistent risks of nuclear technologies and renewable energy alternatives. PMID:27420080

  12. Migration of Contaminated Soil and Airborne Particulates to Indoor Dust

    PubMed Central

    Layton, David W.; Beamer, Paloma I.

    2009-01-01

    We have developed a modeling and measurement framework for assessing transport of contaminated soils and airborne particulates into a residence, their subsequent distribution indoors via resuspension and deposition processes, and removal by cleaning and building exhalation of suspended particles. The model explicitly accounts for the formation of house dust as a mixture of organic matter (OM) such as shed skin cells and organic fibers, soil tracked-in on footwear, and particulate matter (PM) derived from the infiltration of outdoor air. We derived formulas for use with measurements of inorganic contaminants, crustal tracers, OM, and PM to quantify selected transport parameters. Application of the model to residences in the U.S. Midwest indicates that As in ambient air can account for nearly 60% of the As input to floor dust, with soil track-in representing the remainder. Historic data on Pb contamination in Sacramento, CA, was used to reconstruct sources of Pb in indoor dust, showing that airborne Pb was likely the dominant source in the early 1980s. However, as airborne Pb levels declined due to the phase out of leaded gasoline, soil resuspension and track-in eventually became the primary sources of Pb in house dust. PMID:19924944

  13. Organochlorinated pesticide degrading microorganisms isolated from contaminated soil.

    PubMed

    Lovecka, Petra; Pacovska, Iva; Stursa, Petr; Vrchotova, Blanka; Kochankova, Lucie; Demnerova, Katerina

    2015-01-25

    Degradation of selected organochlorinated pesticides (γ-hexachlorocyclohexane - γ-HCH, dichlorodiphenyltrichloroethane - DDT, hexachlorobenzene - HCB) by soil microorganisms was studied. Bacterial strains isolated from contaminated soil from Klatovy-Luby, Hajek and Neratovice, Czech Republic, capable of growth on the selected pesticides were isolated and characterised. These isolates were subjected to characterisation and identification by MS MALDI-TOF of whole cells and sequence analysis of 16S rRNA genes. The isolates were screened by gas chromatography for their ability to degrade the selected pesticides. Some isolates were able to degrade pesticides, and the formation of degradation products (γ-pentachlorocyclohexane (γ-PCCH), dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD)) observed in liquid culture confirmed their degradation capability. The isolates and DNA samples isolated from the contaminated soil were also screened for the bphA1 gene (encoding biphenyl-2,3-dioxygenase, the first enzyme in the PCB degradation pathway) and its occurrence was demonstrated. The isolates were also screened for the presence of linA, encoding dehydrochlorinase, the first enzyme of the HCH degradation pathway. The linA gene could not be found in any of the tested isolates, possibly due to the high specificity of the primers used. The isolates with the most effective degradation abilities could be used for further in situ bioremediation experiments with contaminated soil. PMID:25094051

  14. An analytically based model for the simultaneous leaching-chain decay of radionuclides from contaminated ground surface soil layers.

    PubMed

    Jarzemba, M S; Manteufel, R D

    1997-12-01

    This paper describes an analytically based method for modeling the time-dependent radionuclide areal densities of contaminated soil surface layers when the soil experiences simultaneous leaching, surface erosion and chain radioactive decay. The model is used to predict time-dependent radionuclide areal densities in a volcanic ash blanket contaminated with spent nuclear fuel particles for the purpose of assessing the risks of radiation exposure from an extrusive volcanic event near a proposed high-level waste repository at Yucca Mountain. The method uses general analytical solutions (an expansion of the Bateman equations) for calculating serial decay, including non-radioactive decay loss terms, in order to calculate time-dependent radionuclide areal densities in the ash blanket. In the presented example, 43 "key" radionuclides are tracked and their concentrations in the blanket are displayed for a 10,000-y time period following the volcanic event. Although the analysis presented herein is for modeling contaminated volcanic ash blankets, the model would work equally well for modeling time-dependent radionuclide contamination of land surfaces in, for example, site decommissioning. It is suggested that the general solutions for serial decay (with non-radioactive decay loss terms) can also be used to model the release of radionuclides from the waste packages under anticipated repository conditions. PMID:9373070

  15. Characterization of bacterial communities in heavy metal contaminated soils.

    PubMed

    Roane, T M; Kellogg, S T

    1996-06-01

    Heavy metal pollution is a principle source of environmental contamination. We analyzed heavy metal impacted soil microbial communities and found that, in general, although lead adversely affected biomass, metabolic activity, and diversity, autochthonous lead- and cadmium-resistant isolates were found. In several metal-stressed soils, the microbial community consisted of two populations, either resistant or sensitive to lead. Additionally, a lead-resistant isolate was isolated from a control soil with no known previous exposure to lead, suggesting widespread lead resistance. Lead-resistant genera isolated included Pseudomonas, Bacillus, Corynebacterium, and Enterobacter species. Plasmids, ranging from 5 to 260 kb, were not detected through standard purifications from lead-resistant isolates. Positive correlations existed between antibiotic resistance and isolation habitat for lead-resistant strains, microbial metabolic activity and soil type, soluble lead concentration and microbial diversity, and arsenic concentration and total or viable cell concentrations. PMID:8801006

  16. Metal contamination of vineyard soils in wet subtropics (southern Brazil).

    PubMed

    Mirlean, Nicolai; Roisenberg, Ari; Chies, Jaqueline O

    2007-09-01

    The vine-growing areas in Brazil are the dampest in the world. Copper maximum value registered in this study was as much as 3200 mg kg(-1), which is several times higher than reported for vineyard soils in temperate climates. Other pesticide-derived metals accumulate in the topsoil layer, surpassing in the old vineyards the background value several times for Zn, Pb, Cr and Cd. Copper is transported to deeper soils' horizons and can potentially contaminate groundwater. The soils from basaltic volcanic rocks reveal the highest values of Cu extracted with CaCl(2), demonstrating a high capacity of copper transference into plants. When evaluating the risks of copper's toxic effects in subtropics, the soils from rhyolitic volcanic rocks are more worrisome, as the Cu extracted with ammonium acetate 1M surpasses the toxic threshold as much as 4-6 times. PMID:17321651

  17. Sources of arsenic and fluoride in highly contaminated soils causing groundwater contamination in Punjab, Pakistan

    SciTech Connect

    Farooqi, A.; Masuda, H.; Siddiqui, R.; Naseem, M.

    2009-05-15

    Highly contaminated groundwater, with arsenic (As) and fluoride (F{sup -}) concentrations of up to 2.4 and 22.8 mg/L, respectively, has been traced to anthropogenic inputs to the soil. In the present study, samples collected from the soil surface and sediments from the most heavily polluted area of Punjab were analyzed to determine the F{sup -} and As distribution in the soil. The surface soils mainly comprise permeable aeolian sediment on a Pleistocene terrace and layers of sand and silt on an alluvial flood plain. Although the alluvial sediments contain low levels of F, the terrace soils contain high concentrations of soluble F{sup -} (maximum, 16 mg/kg; mean, 4 mg/kg; pH > 8.0). Three anthropogenic sources were identified as fertilizers, combusted coal, and industrial waste, with phosphate fertilizer being the most significance source of F{sup -} accumulated in the soil. The mean concentration of As in the surface soil samples was 10.2 mg/kg, with the highest concentration being 35 mg/kg. The presence of high levels of As in the surface soil implies the contribution of air pollutants derived from coal combustion and the use of fertilizers. Intensive mineral weathering under oxidizing conditions produces highly alkaline water that dissolves the F{sup -} and As adsorbed on the soil, thus releasing it into the local groundwater.

  18. Geochemistry Of Lead In Contaminated Soils: Effects Of Soil Physico-Chemical Properties

    NASA Astrophysics Data System (ADS)

    Saminathan, S.; Sarkar, D.; Datta, R.; Andra, S. P.

    2006-05-01

    Lead (Pb) is an environmental contaminant with proven human health effects. When assessing human health risks associated with Pb, one of the most common exposure pathways typically evaluated is soil ingestion by children. However, bioaccessibility of Pb primarily depends on the solubility and hence, the geochemical form of Pb, which in turn is a function of site specific soil chemistry. Certain fractions of ingested soil-Pb may not dissociate during digestion in the gastro-intestinal tract, and hence, may not be available for transport across the intestinal membrane. Therefore, this study is being currently performed to assess the geochemical forms and bioaccessibility of Pb in soils with varying physico-chemical properties. In order to elucidate the level of Pb that can be ingested and assimilated by humans, an in-vitro model that simulates the physiological conditions of the human digestive system has been developed and is being used in this study. Four different types of soils from the Immokalee (an acid sandy soil with minimal Pb retention potential), Millhopper (a sandy loam with high Fe/Al content), Pahokee (a muck soil with more than 80% soil organic matter), and Tobosa series (an alkaline soil with high clay content) were artificially contaminated with Pb as lead nitrate at the rate equivalent to 0, 400, 800, and 1200 mg/kg dry soil. Analysis of soils by a sequential extraction method at time zero (immediately after spiking) showed that Immokalee and Millhopper soils had the highest amount of Pb in exchangeable form, whereas Pahokee and Tobosa soils had higher percentages of carbonate-bound and Fe/Al-bound Pb. The results of in-vitro experiment at time zero showed that majority of Pb was dissolved in the acidic stomach environment in Immokalee, Millhopper, and Tobosa, whereas it was in the intestinal phase in Pahokee soils. Because the soil system is not in equilibrium at time zero, the effect of soil properties on Pb geochemistry is not clear as yet. The

  19. Diuron mobility through vineyard soils contaminated with copper.

    PubMed

    Jacobson, Astrid R; Dousset, Sylvie; Guichard, Nathalie; Baveye, Philippe; Andreux, Francis

    2005-11-01

    The herbicide diuron is frequently applied to vineyard soils in Burgundy, along with repeated treatments with Bordeaux mixture (a blend of copper sulfate and calcium hydroxide) that result in elevated copper concentrations. Cu could in principle affect the fate and transport of diuron or its metabolites in the soil either directly by complexation or indirectly by altering the populations or activity of microbes involved in their degradation. To assess the effect of high Cu concentrations on diuron transport, an experiment was designed with ten undisturbed columns of calcareous and acidic soils contaminated with 17--509 mg kg(-1) total Cu (field-applied). Grass was planted on three columns. Diuron was applied to the soils in early May and in-ground lysimeters were exposed to outdoor conditions until November. Less than 1.2% of the diuron applied was found in the leachates as diuron or its metabolites. Higher concentrations were found in the effluents from the grass-covered columns (0.1--0.45%) than from the bare-soil columns (0.02--0.14%), and they were correlated with increases in dissolved organic carbon. The highest amounts of herbicide were measured in acidic-soil column leachates (0.98--1.14%) due to the low clay and organic matter contents of these soils. Cu also leached more readily through the acidic soils (32.8--1042 microg) than in the calcareous soils (9.5--63.4 microg). Unlike in the leachates, the amount of diuron remaining in the soils at the end of the experiment was weakly related to the Cu concentrations in the soils. PMID:15951080

  20. Effect Of Soil Properties On The Geochemical Speciation Of Arsenic In Contaminated Soils: A Greenhouse Study

    NASA Astrophysics Data System (ADS)

    Sharma, S.; Sarkar, D.; Datta, R.

    2005-05-01

    Land-applied arsenical pesticides have contributed elevated soil arsenic (As) levels. Many baseline risk assessments As-contaminated sites assume that all As present in the soil is bioavailable, thereby potentially overestimating the actual health risk. However, risk from As exposure is associated only with those forms of As that are potentially extractable by the human gastrointestinal juices. It has been demonstrated that As may exist in several geochemical forms depending on soil chemical properties, which may or may not be bioavailable. The current study aims at addressing the issue of soil variability on As bioavailability as a function of soil physico-chemical properties in a greenhouse setting involving dynamic interactions between soil, water and plants. Four different soils were chosen based on their potential differences with respect to As reactivity: Immokalee, an acid sand with low extractable Fe/Al, having minimal arsenic retention capacity; Millhopper, an acid sandy loam with high extractable Fe/Al oxides; Pahokee Muck soil with 85% soil organic matter (SOM) as well as high Fe/Al content; and Orelia soil with high clay and Fe/Al content. Soils were amended with sodium arsenate (675 and 1500 mg/Kg). Rice (Oryza sativa) was used as the test crop. A sequential extraction scheme was employed to identify the geochemical forms of As in soils (soluble, exchangeable, organic, Fe/Al-bound, Ca/Mg-bound, residual) immediately after spiking; after 3 mo; and after 6 mo of equilibration time. Concentrations of these As forms were correlated with the in-vitro bioavailable As fractions to identify those As fractions that are most likely to be bioavailable. Results from this study showed that there was little to no plant growth in the contaminated soils. Sequential extractions of the soil indicated that arsenic is strongly adsorbed onto soil amorphous iron/aluminum oxides, and the degree of arsenic retention is a direct function of equilibration time.

  1. Remediation of lead and cadmium-contaminated soils.

    PubMed

    Salama, Ahmed K; Osman, Khaled A; Gouda, Neama Abdel-Razeek

    2016-01-01

    The research was designated to study the ability of plants to bio-accumulate, translocate and remove the heavy metals, lead and cadmium from contaminated soil. The herbal plant ryegrass, Lolium multiflorum was investigated as a bio-accumulator plant for these metals. The translocation of these heavy metals in the herbal plant was compared considering root to shoot transport and redistribution of metals in the root and shoot system. The trace metal contents from root and shoot parts were determined using atomic absorption spectrometer. The results showed that the percent of lead and cadmium transferred to ryegrass plant were averaged as 51.39, and 74.57%, respectively, while those remained in the soil were averaged as 48.61 and 25.43% following 60 days of treatment. The soil-plant transfer index in root and shoot system of ryegrass was found to be 0.32 and 0.20 for lead, and 0.50 and 0.25 for cadmium. These findings indicated that the herbal plant ryegrass, Lolium multiflorum is a good accumulator for cadmium than lead. The soil-plant transfer factor (the conc. of heavy metal in plant to the conc. in soil) indicated that the mechanism of soil remedy using the investigated plant is phytoextraction where the amounts of heavy metals transferred by plant roots into the above ground portions were higher than that remained in the soil. The method offers green technology solution for the contamination problem since it is effective technology with minimal impact on the environment and can be easily used for soil remedy. PMID:26515924

  2. Electrokinetic electrode system for extraction of soil contaminants from unsaturated soils

    DOEpatents

    Lindgren, E.R.; Mattson, E.D.

    1995-07-25

    An electrokinetic electrode assembly is described for use in extraction of soil contaminants from unsaturated soil in situ. The assembly includes a housing for retaining a liquid comprising an electrolyte solution, pure water, and soil water, the housing being in part of porous material capable of holding a vacuum. An electrode is mounted in the housing. The housing is provided with a vacuum orifice for effecting a vacuum within the housing selectively to control flow of soil water through the housing into the chamber and to control outflow of the liquid from the chamber. The assembly further includes conduit means for removing the liquid from the housing and returning the electrolyte solution to the housing, and a conduit for admitting pure water to the housing. An electrode system and method are also revealed for extraction of soil contaminants. The system and method utilize at least two electrode assemblies as described above. 5 figs.

  3. Electrokinetic electrode system for extraction of soil contaminants from unsaturated soils

    DOEpatents

    Lindgren, Eric R.; Mattson, Earl D.

    1995-01-01

    There is presented an electrokinetic electrode assembly for use in extraction of soil contaminants from unsaturated soil in situ. The assembly includes a housing for retaining a liquid comprising an electrolyte solution, pure water, and soil water, the housing being in part of porous material capable of holding a vacuum. An electrode is mounted in the housing. The housing is provided with a vacuum orifice for effecting a vacuum within the housing selectively to control flow of soil water through the housing into the chamber and to control outflow of the liquid from the chamber. The assembly further includes conduit means for removing the liquid from the housing and returning the electrolyte solution to the housing, and a conduit for admitting pure water to the housing. There is further presented an electrode system and method for extraction of soil contaminants, the system and method utilizing at least two electrode assemblies as described above.

  4. [Methodological Approaches to the Organization of Counter Measures Taking into Account Landscape Features of Radioactively Contaminated Territories].

    PubMed

    Kuznetsov, V K; Sanzharova, N I

    2016-01-01

    Methodological approaches to the organization of counter measures are considered taking into account the landscape features of the radioactively contaminated territories. The current status and new requirements to the organization of counter measures in the contaminated agricultural areas are analyzed. The basic principles, objectives and problems of the formation of counter measures with regard to the landscape characteristics of the territory are presented; also substantiated are the organization and optimization of the counter measures in radioactively contaminated agricultural landscapes. PMID:27245009

  5. Monitoring of radioactive contamination of water systems after Chernobyl accident

    SciTech Connect

    Kuznetsov, Y.V.

    1993-12-31

    The contamination of the water systems within the Russian North-West region, the Danube river and the reservoir of the Dnieper River during the period from June 1986 to 1992 was studied. The water reservoirs in the vicinity of the Chernobyl NPP contained suspended matter and the bottom sediments contained a wide range of radionuclides, including the isotopes of Pu and TPE. In the Baltic Sea and the allied river and lake reservoirs the concentrations of {sup 137}Cs ({sup 134}Cs was also detected) increased drastically, however, the concentrations of {sup 90}Sr and plutonium isotopes remained essentially at the global level. The Danube River contained increased concentrations of {sup 137}Cs and {sup 90}Sr as compared with 1985; no rise in the concentration of plutonium was observed. In subsequent years (1987--1990) the concentration of cesium isotopes in the reservoirs decreased sharply; but, on the other hand, their concentrations in sediments increased.

  6. Remediation of Mercury Contaminated Soils at the Miramas Site - 12243

    SciTech Connect

    Potier, G.; Chambon, F.

    2012-07-01

    Beneficial 'new' use of the Miramas Site is the remediation objective for a former light isotope manufacturing facility. Remediation operations will remove contaminated soils and materials and deconstruct facilities. The remediation objective is faced with project challenges and regulatory requirements that dictate/influence the outcome. The operation consists of the remediation of approximately 100,000 cubic meters of soil and the decommissioning of facilities. The types and ranges of waste are the result of historical processing activities (chemical facilities, pyrotechnic components storage, mining component treatment and light isotope manufacturing activities). Mercury is the primary component of the waste, but metals and organic compounds are also possible waste components. A thermal desorption process is used to remove Mercury from the polluted soil while a biological treatment is considered to the organic nitrate compound removal. A focus is done on the technologies used to remediate the Mercury contaminated soil. After few months of operation, the first results confirm that the technology choices were relevant and the soil remediation project is a success. The first successful month of operation at an industrial scale demonstrate that the Thermal Desorption is an efficient and relevant process to remediate large quantity of mercury contaminated soils. The project is on cost and the mercury removal should be end by 2014. The scrubbing is a good way to limit the volume of material to be treated with the Thermal Desorption Unit. The biological treatment is a promising process for the organic nitrate compound removal and testing at a pilot scale will be done in 2012. (authors)

  7. Ecotoxicity of pentachlorophenol in contaminated soil as affected by soil type.

    PubMed

    Banks, M K; Schwab, A P

    2006-01-01

    Four uncontaminated soils were chosen with a wide range of pH, organic carbon, and clay content to allow us to determine the properties that were most influential on pentachlorophenol (PCP) toxicity. The soils were contaminated in the laboratory at concentrations of 50 and 100 mg/kg and target organisms were exposed to the contaminated soil. Germination and emergence of lettuce seedlings was found to be dependent upon PCP concentration and soil type, and responses were highly correlated to extractable concentrations. Earthworms were sensitive to PCP, regardless of soil properties, and mortality was observed in most samples at the 100 mg/kg concentration. Toxic responses by the worms were not strongly related to soil properties or extractable concentrations. The importance of soil chemical and physical properties on toxicity and bioavailability depends upon the target organism. In the case of lettuce seedlings, PCP is acquired through the aqueous phase; therefore, the chemical interaction between PCP and soil controls toxicity. Since earthworms ingest soil and potentially can change the chemical environment of exposure, the impact of soil properties on PCP toxicity is less apparent. PMID:16423718

  8. Combining phytoextraction and biochar addition improves soil biochemical properties in a soil contaminated with Cd.

    PubMed

    Lu, Huanping; Li, Zhian; Fu, Shenglei; Méndez, Ana; Gascó, Gabriel; Paz-Ferreiro, Jorge

    2015-01-01

    The main goal of phytoremediation is to improve ecosystem functioning. Soil biochemical properties are considered as effective indicators of soil quality and are sensitive to various environmental stresses, including heavy metal contamination. The biochemical response in a soil contaminated with cadmium was tested after several treatments aimed to reduce heavy metal availability including liming, biochar addition and phytoextraction using Amaranthus tricolor L. Two biochars were added to the soil: eucalyptus pyrolysed at 600 °C (EB) and poultry litter at 400 °C (PLB). Two liming treatments were chosen with the aim of bringing soil pH to the same values as in the treatments EB and PLB. The properties studied included soil microbial biomass C, soil respiration and the activities of invertase, β-glucosidase, β-glucosaminidase, urease and phosphomonoesterase. Both phytoremediation and biochar addition improved soil biochemical properties, although results were enzyme specific. For biochar addition these changes were partly, but not exclusively, mediated by alterations in soil pH. A careful choice of biochar must be undertaken to optimize the remediation process from the point of view of metal phytoextraction and soil biological activity. PMID:25010741

  9. Stabilization of contaminated soil and wastewater with chemically bonded phosphate ceramics

    SciTech Connect

    Wagh, A.S.; Jeong, S.Y.; Singh, D.

    1997-01-01

    At Argonne National Laboratory, we have developed chemically Bonded phosphate ceramic (CBPC) technology to stabilize the U.S. Department of Energy`s problem mixed waste streams, for which no other stabilization technology is suitable. In this technology, solid waste is mixed with MgO and reacted with aqueous solutions of phosphoric acid or acid phosphates at room temperature to form a slurry that sets in {approx}2 h into a hard and dense ceramic waste form. Initial studies involved stabilizing the surrogate waste streams and then testing the waste forms for leaching of contaminants. After achieving satisfactory performance of the waste forms, we next incorporated actual waste streams at bench scale and produced waste forms that were then tested with the Toxicity Characteristic Leaching Procedure (TCLP). This presentation deals with stabilization of soil contaminated with Cd, Cr, Pb, Ag, Ba, and Hg, and of low-level radioactive wastewater. To enhance the contaminant levels in the soil, we further spiked the soil with additional amounts of Cd, Cr, Pb, and Hg. Both the soil and the wastewater were incorporated in the same waste form by stabilizing them with the CBPC process. The waste forms had a total waste loading of {approx}77 wt.% and were dense with an open porosity of 2.7 vol.% and a density of 2.17 g/cm{sup 3}. Compression strength was 4910 psi. The TCLP results showed excellent immobilization of all the RCRA metals, and radioactive contaminant levels were below the detection limit of 0.2 pCi/mL. Long-term leaching studies using the ANS 16.1 procedure showed that the retention of contaminants is excellent and comparable to or better than most of other stabilization processes. These results demonstrate that the CBPC process is a very superior process for treatment of low level mixed wastes; we therefore conclude that the CBPC process is well suited to the treatment of low-level mixed waste streams with high waste loading.

  10. Characterization and remediation of soils contaminated with uranium.

    PubMed

    Gavrilescu, Maria; Pavel, Lucian Vasile; Cretescu, Igor

    2009-04-30

    Environmental contamination caused by radionuclides, in particular by uranium and its decay products is a serious problem worldwide. The development of nuclear science and technology has led to increasing nuclear waste containing uranium being released and disposed in the environment. The objective of this paper is to develop a better understanding of the techniques for the remediation of soils polluted with radionuclides (uranium in particular), considering: the chemical forms of uranium, including depleted uranium (DU) in soil and other environmental media, their characteristics and concentrations, and some of the effects on environmental and human health; research issues concerning the remediation process, the benefits and results; a better understanding of the range of uses and situations for which each is most appropriate. The paper addresses the main features of the following techniques for uranium remediation: natural attenuation, physical methods, chemical processes (chemical extraction methods from contaminated soils assisted by various suitable chelators (sodium bicarbonate, citric acid, two-stage acid leaching procedure), extraction using supercritical fluids such as solvents, permeable reactive barriers), biological processes (biomineralization and microbial reduction, phytoremediation, biosorption), and electrokinetic methods. In addition, factors affecting uranium removal from soils are furthermore reviewed including soil characteristics, pH and reagent concentration, retention time. PMID:18771850

  11. Enhanced thermal desorption -- Facile removal of PCBs from contaminated soils

    SciTech Connect

    Krabbenhoft, H.O.; Webb, J.L.; Gascoyne, D.G.

    1995-12-31

    The use of certain organic and inorganic materials, when admixed with soils contaminated with polychlorinated biphenyls (PCBs), greatly facilitates the removal of the PCBs by means of an ex situ thermal desorption process. Thus, for example, heating a soil (with an initial PCB concentration of {approximately}700 ppm A-1260) from 25 C to 300 C over a 30-minute period provided remediated soil with a residual PCB level of 53 ppm (92.4% PCB removal). When the experiment was repeated using a sweep of steam (corresponding to a water delivery rate of 1.0 mL/min), the residual PCB level was 10 ppm (98.6% PCB removal). And when steam was passed through the soil admixed with 5% sodium formate, the residual PCB level was only 0.9 ppm (99.9% PCB removal). Several other additives (such as sodium acetate, ammonium carbamate, formic acid) have been shown to be efficacious for enhanced PCB removal via thermal desorption. A design of experiments study was carried out to optimize the process parameters of temperature, time, additive level, and steam flow. A logarithmic transformation of the data afforded a mathematical model (correlation coefficient 0.96) that allows one to employ the enhanced thermal desorption process in a cost-effective manner to remediate contaminated soil (with an initial PCB level of {approximately}8,000 ppm A-1260) such that residual PCB levels of {<=}2 ppm (99.98% PCB removal) are routinely achieved.

  12. Remediation of PCB contaminated soils using iron nano-particles.

    PubMed

    Varanasi, Patanjali; Fullana, Andres; Sidhu, Sukh

    2007-01-01

    In this study, iron nano-particles were used to remediate PCB contaminated soil and an attempt was made to maximize PCB destruction in each treatment step. The results show that nano-particles do aid in the dechlorination process and high PCB destruction efficiencies can be achieved. The destruction efficiency during the preliminary treatment (mixing of soil and iron nano-particles in water) can be increased by increasing the water temperature. The maximum thermal destruction (pyrolysis/combustion of soil after preliminary treatment) of soil-bound PCBs occurs at 300 degrees C in air. A minimum total PCB destruction efficiency of 95% can be achieved by this process. The effect of changing treatment parameters such as type of mixing, time of mixing and mixing conditions and application of other catalysts like iron oxide and V(2)O(5)/TiO(2) was also investigated. It was found that at 300 degrees C in air, iron oxide and V(2)O(5)/TiO(2) are also good catalysts for remediating PCB contaminated soils. PMID:16962632

  13. Phytoremediation of mercury-contaminated soils by Jatropha curcas.

    PubMed

    Marrugo-Negrete, José; Durango-Hernández, José; Pinedo-Hernández, José; Olivero-Verbel, Jesús; Díez, Sergi

    2015-05-01

    Jatropha curcas plants species were tested to evaluate their phytoremediation capacity in soils contaminated by different levels of mercury. The experimental treatments consisted of four levels of mercury concentrations in the soil - T0, T1, T5, and T10 (0, 1, 5, and 10 μg Hg per g soil, respectively). The total mercury content absorbed by the different plant tissues (roots, stems and leaves) was determined during four months of exposure. The growth behavior, mercury accumulation, translocation (TF) and bioconcentration (BCF) factors were determined. The different tissues in J. curcas can be classified in order of decreasing accumulation Hg as follows: roots>leaves>stems. The highest cumulative absorption of the metal occurred between the second and third month of exposure. Maximum TF was detected during the second month and ranged from 0.79 to 1.04 for the different mercury concentrations. Values of BCF ranged from 0.21 to 1.43. Soils with T1 showed significantly higher BCF (1.43) followed by T10 (1.32) and T5 (0.91), all of them at the fourth month. On the other hand TFs were low (range 0.10-0.26) at the en of the experiment. The maximum reduction of biomass (16.3%) occurred for T10 (10 μg Hg g(-1)). In sum, J. curcas species showed high BCFs and low TFs, and their use could be a promising approach to remediating mercury-contaminated soils. PMID:25655698

  14. Copper phytoavailability and uptake by Elsholtzia splendens from contaminated soil as affected by soil amendments.

    PubMed

    Peng, Hong-Yun; Yang, Xiao-E; Jiang, Li-Ying; He, Zhen-Li

    2005-01-01

    Pot and field experiments were conducted to evaluate bioavailability of Cu in contaminated paddy soil (PS) and phytoremediation potential by Elsholtzia splendens as affected by soil amendments. The results from pot experiment showed that organic manure (M) applied to the PS not only remarkably raised the H2O exchangeable Cu, which were mainly due to the increased exchangeable and organic fractions of Cu in the PS by M, but also stimulated plant growth and Cu accumulation in E. splendens. At M application rate of 5.0%, shoot Cu concentration in the plant increased by four times grown on the PS, so as to the elevated shoot Cu accumulation by three times as compared to the control. In the field trial, soil amendments by M and furnace slag (F), and soil preparations like soil capping (S) and soil discing (D) were performed in the PS. Soil capping and discing considerably declined total Cu in the PS. Application of M solely or together with F enhanced plant growth and increased H2O exchangeable Cu levels in the soil. The increased extractability of Cu in the rhizosphere of E. splendens was noted, which may have mainly attributed to the rhizospheric acidification and chelation by dissolved organic matter (DOM), thus resulting in elevating Cu uptake and accumulation by E. splendens. Amendments with organic manure plus furnace slag (MF) to the PS caused the highest exactable Cu with saturated H2O in the rhizospheric soil of E. splendens after they were grown for 170 days in the PS, thus achieving 1.74 kg Cu ha(-1) removal from the contaminated soil by the whole plant of E. splendens at one season, which is higher than those of the other soil treatments. The results indicated that application of organic manure at a proper rate could enhance Cu bioavailability and increase effectiveness of Cu phytoextraction from the contaminated soil by the metal-tolerant and accumulating plant species (E. splendens). PMID:15792303

  15. Natural radioactivity content in soil and indoor air of Chellanam.

    PubMed

    Mathew, S; Rajagopalan, M; Abraham, J P; Balakrishnan, D; Umadevi, A G

    2012-11-01

    Contribution of terrestrial radiation due to the presence of naturally occurring radionuclides in soil and air constitutes a significant component of the background radiation exposure to the population. The concentrations of natural radionuclides in the soil and indoor air of Chellanam were investigated with an aim of evaluating the environmental radioactivity level and radiation hazard to the population. Chellanam is in the suburbs of Cochin, with the Arabian Sea in the west and the Cochin backwaters in the east. Chellanam is situated at ∼25 km from the sites of these factories. The data obtained serve as a reference in documenting changes to the environmental radioactivity due to technical activities. Soil samples were collected from 30 locations of the study area. The activity concentrations of (232)Th, (238)U and (40)K in the samples were analysed using gamma spectrometry. The gamma dose rates were calculated using conversion factors recommended by UNSCEAR [United Nations Scientific Committee on the Effects of Atomic Radiation. Sources and effects of ionizing radiation. UNSCEAR (2000)]. The ambient radiation exposure rates measured in the area ranged from 74 to 195 nGy h(-1) with a mean value of 131 nGy h(-1). The significant radionuclides being (232)Th, (238)U and (40)K, their activities were used to arrive at the absorbed gamma dose rate with a mean value of 131 nGy h(-1) and the radium equivalent activity with a mean value of 162 Bq kg(-1). The radon progeny levels varied from 0.21 to 1.4 mWL with a mean value of 0.6 mWL. The thoron progeny varied from 0.34 to 2.9 mWL with a mean value of 0.85 mWL. The ratio between thoron and radon progenies varied from 1.4 to 2.3 with a mean of 1.6. The details of the study, analysis and results are discussed. PMID:22951996

  16. Assessing the Educational Needs of Urban Gardeners and Farmers on the Subject of Soil Contamination

    ERIC Educational Resources Information Center

    Harms, Ashley Marie Raes; Presley, DeAnn Ricks; Hettiarachchi, Ganga M.; Thien, Stephen J.

    2013-01-01

    Participation in urban agriculture is growing throughout the United States; however, potential soil contaminants in urban environments present challenges. Individuals in direct contact with urban soil should be aware of urban soil quality and soil contamination issues to minimize environmental and human health risks. The study reported here…

  17. LAND TREATMENT OF PAH-CONTAMINATED SOIL: PERFORMANCE MEASURED BY CHEMICAL AND TOXICITY ASSAYS

    EPA Science Inventory

    The performance of a soil remediation process can be determined by measuring the reduction in target soil contaminant concentrations and by assessing the treatment's ability to lower soil toxicity. Land treatment of polycyclic armomatic hydrocarbon (PAH)-contaminated soil from a ...

  18. LAND TREATMENT OF PAH-CONTAMINATED SOIL: PERFORMANCE MEASURED BY CHEMICAL AND TOXICITY ASSAYS

    EPA Science Inventory

    The performance of a soil remediation process can be determined by measuring the reduction in target soil contaminant concentrations and by assessing the treatment's ability to lower soil toxicity. Land treatment of polycyclic aromatic hydrocarbon (PAH)-contaminated soil from a ...

  19. Evaluation of the Effect of Arsenic Contamination on Selected Soil Enzyme Activities and Microbial Diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Environmental impact of different contaminants which enter the soil can alter the diversity of the soil microflora thus disrupting their ability to maintain soil quality and health. Due to the vital role played by the diverse soil microbes in soil, the measurement of the soil microbial diversity has...

  20. [Soil contamination with Toxocara spp. eggs in the Elblag area].

    PubMed

    Jarosz, W

    2001-01-01

    The distribution of Toxocara spp. eggs in Elbl4g was studied. Out of 72 soil samples collected in public places of the city 13.9% were positive and the mean egg density was 3.75/100g soil. The city backyards were much more contaminated with Toxocara spp. eggs (18.0%) than the playgrounds (4.5%). In sandpits examined the eggs were not found. Almost 80% of Toxocara spp. eggs recovered were infective. T. cati eggs were more frequent than T. canis eggs. Additionally in examined samples two eggs of Ancylostoma caninum and one egg of Ascaris lumbricoides were recognized. PMID:16888965

  1. Functioning of metal contaminated garden soil after remediation.

    PubMed

    Jelusic, Masa; Grcman, Helena; Vodnik, Dominik; Suhadolc, Metka; Lestan, Domen

    2013-03-01

    The effect of remediation using three EDTA doses (10, 30, 60 mmol kg(-1)) on soil functioning was assessed using column experiment and Brassica rapa. Soil washing removed up to 77, 29 and 72% of metals from soil contaminated with 1378, 578 and 8.5 mg kg(-1) of Pb, Zn and Cd, respectively. Sequential extraction indicated removal from the carbonate soil fraction. Metal oral-accessibility from the stomach phase was reduced by up to 75 and from the small intestine by up to 79% (Pb). Part of metals (up to 0.8% Cd) was lost due to leaching from columns. Remediation reduced toxic metal soil-root transfer by up to 61% but did not prevent metal accumulation in leaves. The fitness of plants grown on EDTA washed soils (gas exchange, fluorescence) was not compromised. Remediation initially reduced the soil DNA content (up to 29%, 30 mmol kg(-1) EDTA) and changed the structure of microbial population. PMID:23246748

  2. Remediation of Nitrobenzene Contaminated Soil by Combining Surfactant Enhanced Soil Washing and Effluent Oxidation with Persulfate

    PubMed Central

    Yan, Jingchun; Gao, Weiguo; Qian, Linbo; Han, Lu; Chen, Yun; Chen, Mengfang

    2015-01-01

    The combination of surfactant enhanced soil washing and degradation of nitrobenzene (NB) in effluent with persulfate was investigated to remediate NB contaminated soil. Aqueous solution of sodium dodecylbenzenesulfonate (SDBS, 24.0 mmol L-1) was used at a given mass ratio of solution to soil (20:1) to extract NB contaminated soil (47.3 mg kg-1), resulting in NB desorption removal efficient of 76.8%. The washing effluent was treated in Fe2+/persulfate and Fe2+/H2O2 systems successively. The degradation removal of NB was 97.9%, being much higher than that of SDBS (51.6%) with addition of 40.0 mmol L-1 Fe2+ and 40.0 mmol L-1 persulfate after 15 min reaction. The preferential degradation was related to the lone pair electron of generated SO4•−, which preferably removes electrons from aromatic parts of NB over long alkyl chains of SDBS through hydrogen abstraction reactions. No preferential degradation was observed in •OH based oxidation because of its hydrogen abstraction or addition mechanism. The sustained SDBS could be reused for washing the contaminated soil. The combination of the effective surfactant-enhanced washing and the preferential degradation of NB with Fe2+/persulfate provide a useful option to remediate NB contaminated soil. PMID:26266532

  3. Characterization of the Contaminated Soil Under the Hanford 324 Building B Cell, Washington, USA - 12182

    SciTech Connect

    Josephson, Walter S.

    2012-07-01

    The 324 Building on the Hanford site played a key role in radiochemical and metallurgical research programs conducted by DOE. The B hot cell in the 324 Building was the site of high-level waste vitrification research. During clean-out operations in November 2009, a tear was noted in the stainless steel liner on the floor of B Cell. Exposure rate readings taken at various locations in the soil about 0.5 meters below B Cell reached 8,900 Roentgen (R) per hour, confirming the existence of a significant soil contamination field. The source of the radioactive material was likely a 510 L spill from the Canister Fabrication Project, consisting of purified, concentrated Cs-137 and Sr-90 solutions totaling 48,000 TBq (1.3 MCi). MCNP modeling was used to estimate that the measured exposure rates were caused by 5,900 TBq (160 kCi) of Sr- 90 and Cs-137, although additional contamination was thought to exist deeper in the soil column. Two physical soil samples were obtained at different depths, which helped verify the contamination estimates. A detailed exposure rate survey inside B Cell was combined with additional MCNP modeling to estimate that an additional 1,700 TBq (460 kCi) is present just below the floor. Based on the results of the sampling campaign, it is likely that the radioactive material below B Cell is primarily consists of feed solutions from the FRG Canister Fabrication Project, and that it contains purified Sr-90 and Cs-137 with enough actinide carryover to make some of the soil transuranic. The close agreement between the Geoprobe calculations and the physical samples adds confidence that there are more than 3700 TBq (100,000 Ci) of Sr-90 and Cs-137 in the soil approximately 1 meter below the cell floor. The majority of the Cs-137 is contained in the first meter of soil, while significant Sr-90 contamination extends to 10 meters below the cell floor. It is also likely that an additional 15,000 TBq (400,000 Ci) of Cs-137 and Sr-90 activity is present directly

  4. COPING WITH CONTAMINATED SEDIMENTS AND SOILS IN THE URBAN ENVIRONMENT.

    SciTech Connect

    JONES,K.W.; VAN DER LELIE,D.; MCGUIGAN,M.; ET AL.

    2004-05-25

    Soils and sediments contaminated with toxic organic and inorganic compounds harmful to the environment and to human health are common in the urban environment. We report here on aspects of a program being carried out in the New York/New Jersey Port region to develop methods for processing dredged material from the Port to make products that are safe for introduction to commercial markets. We discuss some of the results of the program in Computational Environmental Science, Laboratory Environmental Science, and Applied Environmental Science and indicate some possible directions for future work. Overall, the program elements integrate the scientific and engineering aspects with regulatory, commercial, urban planning, local governments, and community group interests. Well-developed connections between these components are critical to the ultimate success of efforts to cope with the problems caused by contaminated urban soils and sediments.

  5. EFFECTIVE DOSIMETRIC HALF LIFE OF CESIUM 137 SOIL CONTAMINATION

    SciTech Connect

    Jannik, T; P Fledderman, P; Michael Paller, M

    2008-01-09

    In the early 1960s, an area of privately-owned swamp adjacent to the US Department of Energy's Savannah River Site (SRS), known as Creek Plantation, was contaminated by site operations. Studies conducted in 1974 estimated that approximately 925 GBq of {sup 137}Cs was deposited in the swamp. Subsequently, a series of surveys--composed of 52 monitoring locations--was initiated to characterize and trend the contaminated environment. The annual, potential, maximum doses to a hypothetical hunter were estimated by conservatively using the maximum {sup 137}Cs concentrations measured in the soil. The purpose of this report is to calculate an 'effective dosimetric' half-life for {sup 137}Cs in soil (based on the maximum concentrations) and compare it to the effective environmental half-life (based on the geometric mean concentrations).

  6. Advanced Assay Systems for Radionuclide Contamination in Soils

    SciTech Connect

    J. R. Giles; L. G. Roybal; M. V. Carpenter; C. P. Oertel; J. A. Roach

    2008-02-01

    Through the support of the Department of Energy (DOE) Office of Environmental Management (EM) Technical Assistance Program, the Idaho National Laboratory (INL) has developed and deployed a suite of systems that rapidly scan, characterize, and analyze surface soil contamination. The INL systems integrate detector systems with data acquisition and synthesis software and with global positioning technology to provide a real-time, user-friendly field deployable turn-key system. INL real-time systems are designed to characterize surface soil contamination using methodologies set forth in the Multi-Agency Radiation Surveys and Site Investigation Manual (MARSSIM). MARSSIM provides guidance for planning, implementing, and evaluating environmental and facility radiological surveys conducted to demonstrate compliance with a dose or risk-based regulation and provides real-time information that is immediately available to field technicians and project management personnel. This paper discusses the history of the development of these systems and describes some of the more recent examples and their applications.

  7. Large-scale experience with biological treatment of contaminated soil

    SciTech Connect

    Schulz-Berendt, V.; Poetzsch, E.

    1995-12-31

    The efficiency of biological methods for the cleanup of soil contaminated with total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAH) was demonstrated by a large-scale example in which 38,000 tons of TPH- and PAH-polluted soil was treated onsite with the TERRAFERM{reg_sign} degradation system to reach the target values of 300 mg/kg TPH and 5 mg/kg PAH. Detection of the ecotoxicological potential (Microtox{reg_sign} assay) showed a significant decrease during the remediation. Low concentrations of PAH in the ground were treated by an in situ technology. The in situ treatment was combined with mechanical measures (slurry wall) to prevent the contamination from dispersing from the site.

  8. Bioventing vs. prepared beds for remediation of petroleum contaminated soil

    SciTech Connect

    Hazen, T.C.; Lombard, K.H.; Kastner, J.R.

    1996-10-01

    Bioventing is an in situ biostimulation technique that has become extremely popular recently for remediation of near-surface sediment (soil) contaminated with petroleum products. Prepared Bed bioremediation of petroleum contaminated soil involves the use of a centralized controlled above ground facility that uses contained land-farming techniques. Several sites at the U.S. DOE Savannah River Site have been evaluated and remediated using these two technologies. The characterization cost, capital costs, safety, implementation time, remediation rate, monitoring requirements, final disposition requirements, regulatory requirements, and public acceptance make these techniques better then any other conventional technology, e.g. incineration, and make it difficult to decide which of the two is the best alternative. New rapid site characterization and treatability techniques e.g. laser induced fluorescence and microrespirometry, have allowed better decisions as to which of these two technologies is the most appropriate for a given site.

  9. Bioremediation of oil-contaminated soil -- A rate model

    SciTech Connect

    Li, K.Y.; Zhang, Y.; Xu, T.

    1995-12-31

    Three rate equations, a modified Monod equation and two mass transfer rate equations, were used to calculate the biodegradation rate, oxygen transfer rate and oil transfer rate during a bioremediation process of oil-contaminated soil. Based on experimental rate constants, these three rates were calculated and compared. It was found the bioremediation rate of oil-contaminated soil could be controlled by the mass transfer process of oil into aqueous solution (0.12 mg BOD/(1-h)). When the oil transfer rate is enhanced by at least 10 times, the oxygen transfer process (0.1--1.0 mg BOD/(1-h)) becomes the rate-controlling step. For most of the cases, the biodegradation of oil in aqueous solution is not the limiting step unless the microbial population in the aqueous solution is less than 100 mg VSS/1.

  10. The sensitivity of different environments to radioactive contamination.

    PubMed

    Tracy, B L; Carini, F; Barabash, S; Berkovskyy, V; Brittain, J E; Chouhan, S; Eleftheriou, G; Iosjpe, M; Monte, L; Psaltaki, M; Shen, J; Tschiersch, J; Turcanu, C

    2013-08-01

    This paper describes modelling calculations carried out to determine the sensitivity of various rural and semi-natural environments to radionuclide contamination by (137)Cs, (90)Sr, and (131)I released during a major nuclear accident. Depositions of 1000 Bq/m(3) were assumed for each radionuclide. Four broad types of environments were considered: agricultural, forest or tundra, freshwater aquatic, and coastal marine. A number of different models were applied to each environment. The annual dose to a human population receiving most or all of its food and drinking water from a given environment was taken as a broad measure of sensitivity. The results demonstrated that environmental sensitivity was highly radionuclide specific, with (137)Cs generally giving the highest doses during the first year, especially for adults, in terrestrial and freshwater pathways. However, in coastal marine environments, (131)I and (239)Pu were more significant. Sensitivity was time dependent with doses for the first year dominating those for the 2nd and 10th years after deposition. In agricultural environments the ingestion dose from (137)Cs was higher for adults than other age groups, whereas for (90)Sr and (131)I, the ingestion dose was highest for infants. The dependence of sensitivity on social and economic factors such as individual living habits, food consumption preferences, and agricultural practices is discussed. PMID:23517769

  11. Microbial and enzymatic activity of soil contaminated with azoxystrobin.

    PubMed

    Baćmaga, Małgorzata; Kucharski, Jan; Wyszkowska, Jadwiga

    2015-10-01

    The use of fungicides in crop protection still effectively eliminates fungal pathogens of plants. However, fungicides may dissipate to various elements of the environment and cause irreversible changes. Considering this problem, the aim of the presented study was to evaluate changes in soil biological activity in response to contamination with azoxystrobin. The study was carried out in the laboratory on samples of sandy loam with a pH of 7.0 in 1 Mol KCl dm(-3). Soil samples were treated with azoxystrobin in one of four doses: 0.075 (dose recommended by the manufacturer), 2.250, 11.25 and 22.50 mg kg(-1) soil DM (dry matter of soil). The control soil sample did not contain fungicide. Bacteria were identified based on 16S rRNA gene sequencing, and fungi were identified by internal transcribed spacer (ITS) region sequencing. The study revealed that increased doses of azoxystrobin inhibited the growth of organotrophic bacteria, actinomycetes and fungi. The fungicide also caused changes in microbial biodiversity. The lowest values of the colony development (CD) index were recorded for fungi and the ecophysiological (EP) index for organotrophic bacteria. Azoxystrobin had an inhibitory effect on the activity of dehydrogenases, catalase, urease, acid phosphatase and alkaline phosphatase. Dehydrogenases were found to be most resistant to the effects of the fungicide, while alkaline phosphatase in the soil recovered the balance in the shortest time. Four species of bacteria from the genus Bacillus and two species of fungi from the genus Aphanoascus were isolated from the soil contaminated with the highest dose of azoxystrobin (22.50 mg kg(-1)). PMID:26343782

  12. X-231B technology demonstration for in situ treatment of contaminated soil: Laboratory evaluation of chemical oxidation using hydrogen peroxide

    SciTech Connect

    Gates, D.D.; Siegrist, R.L.

    1993-09-01

    Treatability studies were conducted as part of a comprehensive research project initiated to demonstrate as well as evaluate in situ treatment technologies for volatile organic compounds (VOCs) and radioactive substances in wet, slowly permeable soils. The site of interest for this project was the X-231B Oil Biodegradation unit at the Portsmouth Gaseous Diffusion Plant, a US Department of Energy (DOE) facility in southern Ohio. This report describes the treatability studies that investigated the feasibility of the application of low-strength hydrogen peroxide (H{sub 2}O{sub 2}) solutions to treat trichloroethylene (TCE)-contaminated soil.

  13. Coupling bioleaching and electrokinetics to remediate heavy metal contaminated soils.

    PubMed

    Huang, Qingyun; Yu, Zhen; Pang, Ya; Wang, Yueqiang; Cai, Zhihong

    2015-04-01

    In this study, bioleaching was coupled with electrokinetics (BE) to remove heavy metals (Cu, Zn, Cr and Pb) from contaminated soil. For comparison, bioleaching (BL), electrokinetics (EK), and the chemical extraction method were also applied alone to remove the metals. The results showed that the BE method removed more heavy metals from the contaminated soil than the BL method or the EK method alone. The BE method was able to achieve metal solubilization rates of more than 70 % for Cu, Zn and Cr and of more than 40 % for Pb. Within the range of low current densities (<1 mA cm(-2)), higher current density led to more metal removal. However, the metal solubilization rates did not increase with increasing current density when the current density was higher than 1 mA cm(-2). Therefore, it is suggested that bioleaching coupled with electrokinetics can effectively remediate heavy metal-contaminated soils and that preliminary tests should be conducted before field operation to detect the lowest current density for the greatest metal removal. PMID:25680933

  14. Uptake of cesium-137 by crops from contaminated soils

    SciTech Connect

    Demirel, H.; Oezer, I.; Celenk, I.; Halitligil, M.B.; Oezmen, A.

    1994-11-01

    The Turkish tea crop was contaminated following the Chernobyl nuclear accident. Finding ways to dispose of the contaminated tea (Camellia sinensis L.) without damaging the environment was the goal of this research conducted at the Turkish Atomic Energy Authority (TAEA). In this study, an investigation was made of {sup 137}Cs activities of the plants and the ratios of transfer of {sup 137}Cs activity to plants when the contaminated tea was applied to the soil. Experiments were conducted in the field and in pots under greenhouse conditions. The activities of the tea applied in the field ranged from 12 500 to 72 800 Bq/m{sup 2}, whereas this activity was constant at 8000 Bq/pot in the greenhouse experiment. The transfer of {sup 137}Cs from soil to the plants was between 0.037 and 1.057% for wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), corn (Zea mays indentata Sturt), bean (Phaseolus vulgaris L.), lettuce (Lactuca sativa L.), and grass (Lolium perenne L.). The ratio of the transfer of {sup 137}Cs activity to plants increased as the activity {sup 137}Cs in tea applied to soil was increased. The activity in the plants increased due to increased uptake of {sup 137}Cs by plants. 12 refs., 2 figs., 2 tabs.

  15. Restoration of contaminated soils in abandoned mine areas (Tuscany, Italy)

    NASA Astrophysics Data System (ADS)

    Bini, Claudio; Wahsha, Mohammad

    2016-04-01

    In Italy ore research and exploitation have been nearly exhausted since the end of the last century, and have left on the land a huge amount of mine waste, therefore provoking evident environmental damage including surface and groundwater, soils, vegetation and the food chain, and a potential threat to human health. The main processes occurring at these sites are: rock disgregation, fragments migration, dust dispersion, oxidation (Eh>250mV), acidification (pH<7), hydrolisis and metal leaching, precipitation of oxides and sulphates. The restoration of these sites, therefore, is a primary objective, in order to reduce/eliminate the risk associated to the contamination sources of past activities, and the consequent environmental and human health hazard. The increasing environmental consciousness of general population compelled Public Administrators to set down effective legislation acts on this subject (e.g. D.L. 152/2006), and more generally on environmental contamination. In this work we present the results of a survey carried out at several mixed sulphides mine sites in Tuscany, exploited for at least a millennium, and closed in the last century. Biogeochemical analyses carried out on representative soil profiles (Spolic Technosols) and vegetation in the proximal and distal areas of ore exploitation show heavy metal concentrations (Cd, Cu, Fe, Pb, Zn) overcoming legislation limits on average. Ni, Cr and Mn concentrations, instead, are generally below the reference levels. The results obtained suggest that the abandoned mine sites represent actual natural laboratories where to experiment new opportunities for restoration of anthropogenically contaminated areas, and to study new pedogenetic trends from these peculiar parent materials. Moreover, plants growing on these substrates are genetically adapted to metal-enriched soils, and therefore may be utilized in phytoremediation of contaminated sites. Furthermore, the institution of natural parks in these areas could

  16. In-Situ Containment and Extraction of Volatile Soil Contaminants

    SciTech Connect

    Varvel, Mark Darrell

    2005-12-27

    The invention relates to a novel approach to containing and removing toxic waste from a subsurface environment. More specifically the present invention relates to a system for containing and removing volatile toxic chemicals from a subsurface environment using differences in surface and subsurface pressures. The present embodiment generally comprises a deep well, a horizontal tube, at least one injection well, at least one extraction well and a means for containing the waste within the waste zone (in-situ barrier). During operation the deep well air at the bottom of well (which is at a high pressure relative to the land surface as well as relative to the air in the contaminated soil) flows upward through the deep well (or deep well tube). This stream of deep well air is directed into the horizontal tube, down through the injection tube(s) (injection well(s)) and into the contaminate plume where it enhances volatization and/or removal of the contaminants.

  17. In-Situ Contained And Of Volatile Soil Contaminants

    DOEpatents

    Varvel, Mark Darrell

    2005-12-27

    The invention relates to a novel approach to containing and removing toxic waste from a subsurface environment. More specifically the present invention relates to a system for containing and removing volatile toxic chemicals from a subsurface environment using differences in surface and subsurface pressures. The present embodiment generally comprises a deep well, a horizontal tube, at least one injection well, at least one extraction well and a means for containing the waste within the waste zone (in-situ barrier). During operation the deep well air at the bottom of well (which is at a high pressure relative to the land surface as well as relative to the air in the contaminated soil) flows upward through the deep well (or deep well tube). This stream of deep well air is directed into the horizontal tube, down through the injection tube(s) (injection well(s)) and into the contaminate plume where it enhances volatization and/or removal of the contaminants.

  18. Plume-Scale Testing of a Simplified Method for Detecting Tritium Contamination in Plants and Soil

    NASA Astrophysics Data System (ADS)

    Andraski, B. J.; Halford, K. J.; Johnson, M. J.; Michel, R. L.; Radyk, J. C.

    2003-12-01

    Research at the Amargosa Desert Research Site near Beatty, Nevada indicates that tritium movement from a closed low-level radioactive waste facility occurs primarily in the gas phase with preferential transport through coarse-textured sediment layers. However, models for movement of tritiated water vapor at the site fail to predict the extent of transport indicated by field measurements. In order to develop a better understanding of the spatial distribution of tritium contamination in the near-surface environment adjacent to the waste facility, a recently published tritium contamination-detection method was tested for collection and analysis of plume-scale data. The method entails solar distillation of plant water from foliage, followed by filtration and adsorption of scintillation-interfering constituents on a graphite-based solid-phase-extraction column prior to direct-scintillation counting. Samples were collected from 103 plants (creosote bush; Larrea tridentata) within a 72-ha area adjacent to the waste facility. Plant data showed elevated tritium concentrations up to 300 m from the waste facility. For a small ( ˜ 8 ha) area where high-density soil-water vapor data were already available, plant-based and soil-based concentration contours compared favorably. Plant data for previously unmeasured areas identified "hot spots" that were later verified by direct soil measurements. Regression analysis of tritium concentrations from collocated plant- and soil-sampling sites showed that empirical relations could be developed to predict soil concentrations (y) from the more simply determined plant concentrations (x): e.g., the equation for root-zone soil concentrations (Bq/L) was y = 1.156 x + 55.17 (r2 = 0.9521; SEE = 250). Results of this work have improved knowledge of the extent of tritium contamination in the near-surface environment. The pattern of the tritium concentrations indicated that the observed contamination originates from two sources--the waste

  19. A study of augmented bioremediation for gasoline-contaminated soil

    SciTech Connect

    Gross, M.A.; Thoma, G.J.; Tunnel, A.T.

    1995-12-31

    A field-scale study was performed to evaluate the efficacy of augmenting bioremediation of gasoline-contaminated soil using commercially available products. A portion of the contaminated backfill from recently removed underground storage tanks (UST`s) at a bulk fuel facility in Northeast Arkansas was used in this bioremediation study. Seven polyethylene lined bermed areas (cells), were filled with 3.8 cubic meters (5 cubic yards) of contaminated soil. The USTs had leaked gasoline, diesel and kerosene into the surrounding soil. Four bioaugmentation product vendors participated; each one demonstrated their product in a separate cell. An additional cell was subjected to soil vapor extraction, and the remaining two were used as experimental controls. One control cell remained covered with polyethylene sheeting for the duration of the study period. The other control cell was subjected to mechanical processes similar to the bloaugmented cells. That is, if a vendor rototilled his cell, the control cell was rototilled with a clean rototiller, however, no soil amendments or microorganisms were added. Samples were collected from each comer and the center of each cell over a 39 week period. A composite sample for each cell was placed in a glass sample, container with a lid, packed on ice and delivered to an analytical laboratory for total petroleum hydrocarbon (TPH) analysis. After 39 weeks, the covered control showed little or no decrease in TPH concentration. The remaining cells all had varying degrees of TPH loss. However, the bioaugmentation products did not significantly outperform the tilled control. Both the fertilized control and the oil vapor extraction treatments proved to be nearly as effective as the best of the products and significantly better than two of the products in terms of final TPH and the first order removal rate constant.

  20. Radioactive waste disposal implications of extending Part IIA of the Environmental Protection Act to cover radioactively contaminated land.

    PubMed

    Nancarrow, D J; White, M M

    2004-03-01

    A short study has been carried out of the potential radioactive waste disposal issues associated with the proposed extension of Part IIA of the Environmental Protection Act 1990 to include radioactively contaminated land, where there is no other suitable existing legislation. It was found that there is likely to be an availability problem with respect to disposal at landfills of the radioactive wastes arising from remediation. This is expected to be principally wastes of high volume and low activity (categorised as low level waste (LLW) and very low level waste (VLLW)). The availability problem results from a lack of applications by landfill operators for authorisation to accept LLW wastes for disposal. This is apparently due to perceived adverse publicity associated with the consultation process for authorisation coupled with uncertainty over future liabilities. Disposal of waste as VLLW is limited both by questions over volumes that may be acceptable and, more fundamentally, by the likely alpha activity of wastes (originating from radium and thorium operations). Authorised on-site disposal has had little attention in policy and guidance in recent years, but may have a part to play, especially if considered commercially attractive. Disposal at BNFL's near surface disposal facility for LLW at Drigg is limited to wastes for which there are no practical alternative disposal options (and preference has been given to operational type wastes). Therefore, wastes from the radioactively contaminated land (RCL) regime are not obviously attractive for disposal to Drigg. Illustrative calculations have been performed based on possible volumes and activities of RCL arisings (and assuming Drigg's future volumetric disposal capacity is 950,000 m3). These suggest that wastes arising from implementing the RCL regime, if all disposed to Drigg, would not represent a significant fraction of the volumetric capacity of Drigg, but could have a significant impact on the radiological

  1. Comparison of Kriging and coKriging for soil contamination mapping in abandoned mine sites

    NASA Astrophysics Data System (ADS)

    Lee, Hyeongyu; Choi, Yosoon

    2015-04-01

    Soil contamination mapping around abandoned mines is an important task for the planning and design of mine reclamation. This study compared the ordinary Kriging and the co-Kriging methods for the soil contamination mapping in abandoned mine sites. Four approaches were conducted as follows: (1) soil contamination mapping using the ordinary Kriging and Inductively Coupled Plasma (ICP) data only; (2) soil contamination mapping using the ordinary Kriging and Portable X-Ray Fluorescence (PXRF) data only; (3) soil contamination mapping using the ordinary Kriging and integrated data from ICP and PXRF; and (4) soil contamination mapping using the co-Kriging and integrated data from ICP and PXRF. Results indicate that the approach 3 provides substantial improvements over other three approaches including a more reasonable spatial pattern of soil contamination and reduction in the error of its estimates.

  2. Effect of clays and cement on the solidification/stabilization of phenol-contaminated soils

    SciTech Connect

    Vipulanandan, C.

    1995-12-31

    Solidification/stabilization of phenol-contaminated soil was investigated by studying the interaction between soil, phenol and cement. The soil (with 20% kaolinite or bentonite clay) was contaminated with phenol up to 2,000 mg/kg. Type I Portland cement was used as the binder (20% by weight of contaminated soil) in the solidification/stabilization (S/S) treatment. In the phenol-cement interaction studies, the effect of various phenol concentrations on cement setting time, strength and pore fluid composition was studied. Phenol increased the initial and final setting time of cement and reduced the compressive strength. More than 85% of the phenol was desorped from the contaminated soils. The compressive strength of treated, contaminated soil decreased with higher phenol content but increased with curing time. Leachability of phenol from the solidified cement and treated, contaminated soil cured up to 180 days, was evaluated using the US EPA recommended Toxicity Characteristic Leaching Procedure (TCLP) and the American Nuclear Society`s ANS 16.1 leaching test. The percentage of phenol leached from the solidified contaminated soil was independent of the initial concentration of phenol in the contaminated soil. While the TCLP tests on treated soils showed that over 70% of phenol in the contaminated soil was leached out, the ANS 16.1 tests showed less than 35% phenol in the leachate. A simple model has been proposed to quantify the phenol leached from the cement-solidified, contaminated soil during both leaching tests.

  3. Physical properties, structure, and shape of radioactive Cs from the Fukushima Daiichi Nuclear Power Plant accident derived from soil, bamboo and shiitake mushroom measurements.

    PubMed

    Niimura, Nobuo; Kikuchi, Kenji; Tuyen, Ninh Duc; Komatsuzaki, Masakazu; Motohashi, Yoshinobu

    2015-01-01

    We conducted an elution experiment with contaminated soils using various aqueous reagent solutions and autoradiography measurements of contaminated bamboo shoots and shiitake mushrooms to determine the physical and chemical characteristics of radioactive Cs from the Fukushima Daiichi Nuclear Power Plant accident. Based on our study results and data in the literature, we conclude that the active Cs emitted by the accident fell to the ground as granular non-ionic materials. Therefore, they were not adsorbed or trapped by minerals in the soil, but instead physically adhere to the rough surfaces of the soil mineral particles. Granular Cs* can be transferred among media, such as soils and plants. The physical properties and dynamic behavior of the granular Cs* is expected to be helpful in considering methods for decontamination of soil, litter, and other media. PMID:24445055

  4. A method to estimate the concentration of elements in smoke from burning vegetation growing in contaminated soil

    SciTech Connect

    Murphy, C.E. Jr.

    1991-03-04

    The Savannah River Site has areas where soil is contaminated with metals and/or radionuclides. Many of these areas are surrounded by native vegetation which is growing adjacent to the area and where the roots have penetrated into the contaminated soil of the area. In some cases vegetation has actually invaded the contaminated area. Even though the volume of contaminated vegetation is small, there are problems associated with its disposal. Vegetation decomposes quickly after burial and the volume of buried vegetation can decrease. The voids left can lead to subsidence and possible failure of the clay cap constructed over hazardous and/or radioactive waste burial grounds. An alternative to burying the wood is to burn it and bury the ash. However, burning will introduce the contamination in the vegetation into the air where there is potential for inhalation of the contaminants. A procedure is described to assess the hazard associated with inhalation of contamination from burning of vegetation growing in contaminated soil. The procedure is applied to evaluation of the consequence of burning vegetation grown adjacent to and in the SRL Seepage Basins. The results indicate that burning the vegetation during the day could introduce a level of contaminants to the atmosphere that could cause an exposure greater than the 1 mrem recommended as negligible by the National Council on Radiation Protection and Measurements but lower than the US Department of Energy 100 mrem release guide. A scenario is also investigated where the largest volume of wood, associated with the least contaminated area, is burned. The air concentrations are significantly decreased by this strategy although the total dose commitment due to all radionuclides is still above the 1 mrem dose guide.

  5. Electrokinetic removal of uranium from contaminated, unsaturated soils

    SciTech Connect

    Booher, W.F.; Lindgren, E.R.; Brady, P.V.

    1997-01-01

    Electrokinetic remediation of uranium-contaminated soil was studied in a series of laboratory-scale experiments in test cells with identical geometry using quartz sand at approximately 10 percent moisture content. Uranium, when present in the soil system as an anionic complex, could be migrated through unsaturated soil using electrokinetics. The distance that the uranium migrated in the test cell was dependent upon the initial molar ratio of citrate to uranium used. Over 50 percent of the uranium was recovered from the test cells using the citrate and carbonate complexing agents over of period of 15 days. Soil analyses showed that the uranium remaining in the test cells had been mobilized and ultimately would have been extracted. Uranium extraction exceeded 90 percent in an experiment that was operated for 37 days. Over 70 percent of the uranium was removed from a Hanford waste sample over a 55 day operating period. Citrate and carbonate ligand utilization ratios required for removing 50 percent of the uranium from the uranium-contaminated sand systems were approximately 230 moles ligand per mole uranium and 1320 moles ligand per mole uranium for the waste. Modifying the operating conditions to increasing the residence time of the complexants is expected to improved the utilization efficiency of the complexing agent.

  6. Environmental toxicity testing of contaminated soil based on microcalorimetry.

    PubMed

    Gruiz, K; Feigl, V; Hajdu, Cs; Tolner, M

    2010-10-01

    Contaminated site assessment and monitoring requires efficient risk-management tools including innovative environmental toxicity tests. The first application of microcalorimetry for toxicity testing draw the attention to a possible new tool to increase sensitivity, to eliminate matrix effect and to study effect-mechanism. A Thermal Activity Monitor (TAM) microcalorimeter was used for measuring the heat production of various test organisms when getting in contact with sterile toxic soils. Well known bacterial (Azomonas agilis), animal (Folsomia candida) and plant test organisms (Sinapis alba) were tested for heat production. The heat response of selected testorganisms was measured in case of metal (Cu and Zn) and organic pollutant (Diesel oil, DBNPA and PCP) contaminated soils. In addition to the quantitative determination of the heat production, the mechanism of the toxic effect can be characterized from the shape of the power-time curve (slope of the curve, height and time of the maximum). In certain concentration ranges the higher the pollutant concentration of the soil the lower the maximum of the time-heat curve. At low pollutant concentrations an increased heat production was measured in case of A. agile and 20 and 200 mg Zn kg(-1) soil. The microcalorimetric testing was more sensitive in all cases than the traditional test methods. Our results showed that the microcalorimetric test method offers a new and sensitive option in environmental toxicology, both for research and routine testing. PMID:20549622

  7. Development of Fungal Inocula for Bioaugmentation of Contaminated Soils

    PubMed Central

    Lestan, D.; Lamar, R. T.

    1996-01-01

    This report describes novel fungal inocula for bioaugmentation of soils contaminated with hazardous organic compounds. The inocula are in the form of pelleted solid substrates coated with a sodium alginate suspension of fungal spores or mycelial fragments and incubated until overgrown with the mycelium of selected lignin-degrading fungi. The organisms evaluated were Phanerochaete chrysosporium (BKM F-1767, ATCC 42725), P. sordida (HHB-8922-Sp), Irpex lacteus (Mad-517, ATCC 11245), Bjerkandera adusta (FP-135160-Sp, ATCC 62023), and Trametes versicolor (MD-277). The pelleted fungal inocula resisted competition and proliferation from indigenous soil microbes, were lower in moisture content than current fungal inocula, and had sufficient mechanical strength to allow handling and introduction into the soil without a change in the mechanical consistency of the pellets. Inoculated at a rate of 3% in artificially contaminated nonsterile soil, I. lacteus, B. adusta, and T. versicolor removed 86, 82, and 90%, respectively, of the pentachlorophenol in 4 weeks. A mathematical model was developed to explain moisture distribution in a hydrogel-coated pelleted substrate. PMID:16535337

  8. Analytical characterization of contaminated soils from former manufactured gas plants

    SciTech Connect

    Haeseler, F.; Blanchet, D.; Vandecasteele, J.P.; Druelle, V.; Werner, P.

    1999-03-15

    Detailed analytical characterization of the organic matter (OM) of aged polluted soils from five former manufactured gas plants (MGP) and of two coal tars was completed. It was aimed at obtaining information relevant to the physicochemical state of the polycyclic aromatic hydrocarbon (PAH) pollutants and to their in-situ evolution in time. Overall characterization of total OM (essentially polluting OM) was carried out directly on soil samples with or without prior extraction with solvent. It involved a technique of pyrolysis/oxidation coupled to flame ionization/thermal conductivity detection. Extracts in solvent were fractionated by liquid chromatography into saturated hydrocarbons, PAH, and resins, the first two fractions being further characterized by gas chromatography and mass spectrometry. The compositions of OM of soils were found to be very similar. A total of 28% of organic carbon, including all PAH, was extractable by solvent. The compositions of coal tars were qualitatively similar to those of OM of MGP soils but with a higher proportion (48%) of total extractable OM and of PAH, in particular lower PAH. Contamination of MGP soils appeared essentially as coal tar having undergone natural attenuation. The constant association of PAH with heavy OM in MGP soils is important with respect to the mobility and bioaccessibility of these pollutants.

  9. An approach to detecting delayed effects of radioactive contamination on industrial-urban-area dwellers

    SciTech Connect

    Privalova, L.I.; Katsnelson, B.A. ); Polzik, E.V.; Kazantsev, V.S. ); Lipatov, G.Ya. ); Beikin, Y.B. )

    1994-05-01

    Detecting changes in humans that result from radioactive contamination of the area of residence many years after an incident (i.e., when the radiation has substantially decayed) presents a difficult epidemiological problem. Problems of this kind are even more complicated in areas where the population is continually exposed to other harmful man-made factors. The city of Kamensk-Uralsky (Sverdlovsk region, Russia) is a good case in point. In 1957, part of Kamensk-Uralsky was contaminated as the result of an accident at the Kyshtym nuclear plant. In addition, the population of the contaminated area is being exposed to atmospheric emissions from several industrial enterprises. Two comparable groups of residents were formed: one in the contaminated area and another in a control area within the same city characterized by similar levels of chemical pollution but substantially lower radioactive contamination. The groups were composed of only those people who had been living in these areas continually since time of the accident and who were under 15 years of age at the time of the accident. The groups were matched by sex, age, and socio-occupational characteristics. For each subject, data were gathered on more than 50 parameters including hematological, immunological, and biochemical indices of the health status. All these data were obtained from blood tests taken in the fall of 1992. Data processing was carried out with the help of a computerized mathematical pattern recognition methodology, which ensured reliable discrimination between the generalized health status in the areas under study. We found that the health status of inhabitants of the area more contaminated with radioactive fallouts were adversely affected by radiation.

  10. An approach to detecting delayed effects of radioactive contamination on industrial-urban-area dwellers.

    PubMed

    Privalova, L I; Katsnelson, B A; Polzik, E V; Kazantsev, V S; Lipatov GYa; Beikin, Y B

    1994-05-01

    Detecting changes in humans that result from radioactive contamination of the area of residence many years after an incident (i.e., when the radiation has substantially decayed) presents a difficult epidemiological problem. Problems of this kind are even more complicated ina areas where the population is continually exposed to other harmful man-made factors. The city of Kamensk-Uralsky (Sverdlovsk region, Russia) is a good case in point. In 1957, part of Kamensk-Uralsky was contaminated as the result of an accident at the Kyshtym nuclear plant. In addition, the population of the contaminated area is being exposed to atmospheric emissions from several industrial enterprises. Two comparable groups of residents were formed: one in the contaminated are and another in a control area within the same city characterized by similar levels of chemical pollution but substantially lower radioactive contamination. The groups were composed of only those people who had been living in these areas continually since time of the accident and who were under 15 years of age at the time of the accident. The groups were matched by sex, age, and socio-occupational characteristics. For each subject, data were gathered on more than 50 parameters including hematological, immunological, and biochemical indices of the health status. All these data were obtained from blood tests taken in the fall of 1992. Data processing was carried out with the help of a computerized mathematical pattern recognition methodology, which ensured reliable discrimination between the generalized health status in the areas under study. We found that the health status of inhabitants of the area more contaminated with radioactive fallouts was adversely affected by radiation. PMID:8593851

  11. Fixation of soil surface contamination using natural polysaccharides

    SciTech Connect

    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.

  12. [Stabilization and long-term effect of chromium contaminated soil].

    PubMed

    Wang, Jing; Luo, Qi-Shi; Zhang, Chang-Bo; Tan, Liang; Li, Xu

    2013-10-01

    Short-term (3 d and 28 d) and long-term (1 a) stabilization effects of Cr contaminated soil were investigated through nature curing, using four amendments including ferrous sulfide, ferrous sulfate, zero-valent iron and sodium dithionite. The results indicated that ferrous sulfide and zero-valent iron were not helpful for the stabilization of Cr(VI) when directly used because of their poor solubility and immobility. Ferrous sulfate could effectively and rapidly decrease total leaching Cr and Cr(VI) content. The stabilization effect was further promoted by the generation of iron hydroxides after long-term curing. Sodium dithionite also had positive effect on soil stabilization. Appropriate addition ratio of the two chemicals could help maintain the soil pH in range of 6-8. PMID:24364328

  13. Enhanced bioremediation of petroleum contaminated soils with higher plants

    SciTech Connect

    Schwab, A.P.; Banks, M.K.

    1996-10-01

    Introduction of higher plants into a bioremediation system can enhance degradation of total petroleum hydrocarbons and target compounds, particularly relatively immobile and recalcitrant organic molecules. Over the past several years, an interdisciplinary team of civil engineers, chemical engineers, soil chemists, soil microbiologists, and plant scientists at Kansas State University have been studying phytoremediation systems. Greenhouse experiments have focused on selecting plants that are most adapted to degrading target compounds and to surviving in soils highly contaminated with petroleum hydrocarbons. Plant species do not seem to differ in their ability to aid in the decomposition of pyrene and anthracene, but benzo[a]pyrene is much more difficult to degrade. Most species are ineffective in enhancing the degradation of benzo[a]pyrene. Four field studies have been initiated in California, Texas, New Jersey, and Virginia to test some of our greenhouse observations.

  14. Effect of soil properties, heavy metals and emerging contaminants in the soil nematodes diversity.

    PubMed

    Gutiérrez, Carmen; Fernández, Carlos; Escuer, Miguel; Campos-Herrera, Raquel; Beltrán Rodríguez, M Eulalia; Carbonell, Gregoria; Rodríguez Martín, Jose Antonio

    2016-06-01

    Among soil organisms, nematodes are seen as the most promising candidates for bioindications of soil health. We hypothesized that the soil nematode community structure would differ in three land use areas (agricultural, forest and industrial soils), be modulated by soil parameters (N, P, K, pH, SOM, CaCO3, granulometric fraction, etc.), and strongly affected by high levels of heavy metals (Cd, Pb, Zn, Cr, Ni, Cu, and Hg) and emerging contaminants (pharmaceuticals and personal care products, PPCPs). Although these pollutants did not significantly affect the total number of free-living nematodes, diversity and structure community indices vastly altered. Our data showed that whereas nematodes with r-strategy were tolerant, genera with k-strategy were negatively affected by the selected pollutants. These effects diminished in soils with high levels of heavy metals given their adaptation to the historical pollution in this area, but not to emerging pollutants like PPCPs. PMID:26895540

  15. Uptake and transport of radioactive nickel and cadmium into three vegetables after wet aerial contamination.

    PubMed

    Fismes, Joëlle; Echevarria, Guillaume; Leclerc-Cessac, Elisabeth; Morel, Jean Louis

    2005-01-01

    Knowledge of radionuclide or trace element retention and translocation to plants following an aerial contamination event, for example, sprinkling with contaminated water, is necessary for the evaluation of human exposure through consumption of contaminated vegetables. The fate of 63Ni and 109Cd in all plant parts of three different vegetables after wet deposition on leaves or on fruits was studied. Lettuce (Lactuca sativa L.), radish (Raphanus sativus L.), and bean (Phaseolus vulgaris L.) grown under controlled conditions in a growth chamber were contaminated with 63Ni and 109Cd either on leaves, by means of two different contamination methods (a single early contamination and a repetitive one), or on bean husks (third contamination method: a single contamination at a late stage). Spiked and nonspiked organs were harvested at maturity and radionuclide contents were measured. The fraction retained was on average 56% of the initially administered doses of 63Ni and 87% of 109Cd. The leaf-to-other organ translocation factor was considerably higher for 63Ni (on average 43% of retained radioactivity) than for 109Cd (8%). Nickel-63 migrated throughout the whole plant following foliar contamination, and mainly toward young leaves, seeds in formation, and sink organs, whereas 109Cd migrated to a much lesser extent and only to the organs that were closest to the spiked one, and not at all into fruit. After a fruit contamination event, both radionuclides were translocated into the seeds of spiked fruits. Radionuclide retention and translocation were not affected by plant species, but principally by the type of organ contaminated. PMID:16091602

  16. Evaluation of the phytostabilisation efficiency in a trace elements contaminated soil using soil health indicators.

    PubMed

    Pardo, T; Clemente, R; Epelde, L; Garbisu, C; Bernal, M P

    2014-03-15

    The efficiency of a remediation strategy was evaluated in a mine soil highly contaminated with trace elements (TEs) by microbiological, ecotoxicological and physicochemical parameters of the soil and soil solution (extracted in situ), as a novel and integrative methodology for assessing recovery of soil health. A 2.5-year field phytostabilisation experiment was carried out using olive mill-waste compost, pig slurry and hydrated lime as amendments, and a native halophytic shrub (Atriplex halimus L.). Comparing with non-treated soil, the addition of the amendments increased soil pH and reduced TEs availability, favoured the development of a sustainable vegetation cover (especially the organic materials), stimulated soil microorganisms (increasing microbial biomass, activity and functional diversity, and reducing stress) and reduced direct and indirect soil toxicity (i.e., its potential associated risks). Therefore, under semi-arid conditions, the use of compost and pig slurry with A. halimus is an effective phytostabilisation strategy to improve soil health of nutrient-poor soils with high TEs concentrations, by improving the habitat function of the soil ecosystem, the reactivation of the biogeochemical cycles of essential nutrients, and the reduction of TEs dissemination and their environmental impact. PMID:24468528

  17. Data Collection Handbook to Support Modeling Impacts of Radioactive Material in Soil and Building Structures

    SciTech Connect

    Yu, Charley; Kamboj, Sunita; Wang, Cheng; Cheng, Jing-Jy

    2015-09-01

    This handbook is an update of the 1993 version of the Data Collection Handbook and the Radionuclide Transfer Factors Report to support modeling the impact of radioactive material in soil. Many new parameters have been added to the RESRAD Family of Codes, and new measurement methodologies are available. A detailed review of available parameter databases was conducted in preparation of this new handbook. This handbook is a companion document to the user manuals when using the RESRAD (onsite) and RESRAD-OFFSITE code. It can also be used for RESRAD-BUILD code because some of the building-related parameters are included in this handbook. The RESRAD (onsite) has been developed for implementing U.S. Department of Energy Residual Radioactive Material Guidelines. Hydrogeological, meteorological, geochemical, geometrical (size, area, depth), crops and livestock, human intake, source characteristic, and building characteristic parameters are used in the RESRAD (onsite) code. The RESRAD-OFFSITE code is an extension of the RESRAD (onsite) code and can also model the transport of radionuclides to locations outside the footprint of the primary contamination. This handbook discusses parameter definitions, typical ranges, variations, and measurement methodologies. It also provides references for sources of additional information. Although this handbook was developed primarily to support the application of RESRAD Family of Codes, the discussions and values are valid for use of other pathway analysis models and codes.

  18. The effects of soil amendments on heavy metal bioavailability in two contaminated Mediterranean soils.

    PubMed

    Walker, David J; Clemente, Rafael; Roig, Asuncion; Bernal, M Pilar

    2003-01-01

    Two heavy metal contaminated calcareous soils from the Mediterranean region of Spain were studied. One soil, from the province of Murcia, was characterised by very high total levels of Pb (1572 mg kg(-1)) and Zn (2602 mg kg(-1)), whilst the second, from Valencia, had elevated concentrations of Cu (72 mg kg(-1)) and Pb (190 mg kg(-1)). The effects of two contrasting organic amendments (fresh manure and mature compost) and the chelate ethylenediaminetetraacetic acid (EDTA) on soil fractionation of Cu, Fe, Mn, Pb and Zn, their uptake by plants and plant growth were determined. For Murcia soil, Brassica juncea (L.) Czern. was grown first, followed by radish (Raphanus sativus L.). For Valencia soil, Beta maritima L. was followed by radish. Bioavailability of metals was expressed in terms of concentrations extractable with 0.1 M CaCl2 or diethylenetriaminepentaacetic acid (DTPA). In the Murcia soil, heavy metal bioavailability was decreased more greatly by manure than by the highly-humified compost. EDTA (2 mmol kg(-1) soil) had only a limited effect on metal uptake by plants. The metal-solubilising effect of EDTA was shorter-lived in the less contaminated, more highly calcareous Valencia soil. When correlation coefficients were calculated for plant tissue and bioavailable metals, the clearest relationships were for Beta maritima and radish. PMID:12531318

  19. Evaluation of a soil slurry reactor system for treating soil contaminated with munitions compounds

    SciTech Connect

    Boopathy, R.; Manning, J.; Montemagno, C.; Kulpa, C.F.

    1994-05-01

    Two 0.5-L semicontinuous soil slurry reactors were operated for seven months to evaluate the performance of the slurry reactor system in bioremediating soil contaminated with munitions compounds. Nitrogen and carbon were supplemented. The soil slurry was mixed continuously and aerated 10 min/day. Ten percent of the contaminated soil was replaced every week. The 2,4,6-trinitrotoluene (TNT) concentration in soil began to drop after 15 days of treatment, falling to less than 0.5 mg/kg from 7800 mg/kg. Total plate counts in both reactors indicated that the bacterial population was maintained, with an average plate count of about 10{sup 8} CFU/mL. The soil slurry was slightly acidic. In addition to TNT, the slurry reactor also removed the other munitions compounds trinitrobenzene (TNB), 2,4-dinitrotoluene (2,4-DNT), RDX, and HMX. Radiolabeling studies on the reactor biomass showed that 23% of [{sup C}14]TNT was mineralized, while 27% was used as biomass and 8% was adsorbed on to the soil. The rest of the [{sup 14}C]TNT was accounted for as TNT metabolites. Increasing the frequency of soil replacement from once to two or three times weekly did not affect the TNT removal rates. However, the slurry system showed signs of stress, with highly acidic conditions and low oxygen uptake rates.

  20. US Food and Drug Administration draft recommendations on radioactive contamination of food

    SciTech Connect

    Thompson, D.L.

    1995-12-31

    Recommendations on accidental radioactive contamination of human food were issued in 1982 by the Food and Drug Administration (FDA). The recommendations provided guidance to State and local government officials in the exercise of their respective authorities, and were applicable to emergency response planning and to the conduct of radiation protection activities associated with the production, processing, distribution, and use of human food accidentally contaminated with radioactive material. Review of the 1982 FDA recommendations, stimulated by the events following the 1986 accident at Chernobyl, indicated that it would be appropriate to update the recommendations to incorporate newer scientific information and radiation protection philosophy, to include experience gained since 1982, and to take into account international advances. This paper presents a brief outline of the FDA`s approach to its draft revision. the most recent draft was circulated for interagency review in November 1994. Modification made in response to the comments received are included in this paper. 20 refs., 6 tabs.

  1. Method of determining whether radioactive contaminants are inside or outside a structure

    DOEpatents

    Lattin, Kenneth R.

    1977-01-01

    A measure is obtained of the relative quantities of radioactive material inside and outside a structure such as a pipe by obtaining two spectra of gamma radiation on a dummy structure of the same shape and composition. A first spectrum is obtained with a quantity of the radioactive element to be measured located inside the structure and a second spectrum is obtained with a quantity of the same contaminant located outside the structure. The two spectra are normalized to the same equivalent value in a portion of the spectrum that does not reflect the presence of gamma rays resulting from Compton scattering in the structure. Comparison of that portion of the spectra obtained where Compton scattering is a factor gives a measure of the relative amounts of contaminants inside and outside the structure on a spectrum obtained from a test structure. The invention may also be practiced by obtaining a plurality of spectra at varying known concentrations inside and outside the dummy structure.

  2. [Protection of the Croatian population from accidental radioactive contamination of the food chain].

    PubMed

    Lokobauer, N; Franić, Z; Bauman, A

    1993-03-01

    The paper indicates the importance of investigating radionuclide translocation in the human food chain, and the contribution of selected food components in total exposure of the population after accidental radioactive contamination. Data on radioactive contamination and risk assessment of the Croatian population after the Chernobyl nuclear accident are given and possibilities of decontamination of food chain components are discussed. Literature data on radionuclide removal from the human food chain are compared to the results of own investigations. Emphasis is placed on biologically most important radionuclides, 131I, 90Sr, 137Cs, and the most effective means of protection are sought. The preventive measures following a nuclear accident should be based on the cost-benefit principle i.e. the damage from applying radiation protection measures should not exceed the benefit from possible dose reduction. PMID:8347101

  3. A United States perspective on long-term management of areas contaminated with radioactive materials.

    PubMed

    Jones, C Rick

    2004-01-01

    The US has far-reaching and extensive experience in the long-term management of areas contaminated with radioactive materials. This experience base includes the Department of Energy's continued follow-up with Hiroshima and Nagasaki from the 1940s at the Radiological Effects Research Foundation in Hiroshima, Japan, the long-term management of the Marshall Islands Programme, the clean-up of the US nuclear weapons complex and the ongoing management of accident sites such as in Palomares, Spain. This paper discusses the lessons learnt and best practices gained from this far-reaching and extensive experience in the long-term management of areas contaminated with radioactive materials. PMID:15238660

  4. Status of Activities on Rehabilitation Of Radioactively Contaminated Facilities and the Site of Russian Research Center ''Kurchatov Institute''

    SciTech Connect

    Volkov, V. G.; Ponomarev-Stepnoi, N. N.; Melkov, E. S; Ryazantsev, E. P.; Dikarev, V. S.; Gorodetsky, G. G.; Zverkov, Yu. A.; Kuznetsov, V. V.; Kuznetsova, T. I.

    2003-02-25

    This paper describes the program, the status, and the course of activities on rehabilitation of radioactively contaminated facilities and the territory of temporary radioactive waste (radwaste) disposal at the Russian Research Center ''Kurchatov Institute'' (RRC KI) in Moscow as performed in 2001-2002. The accumulation of significant amounts of radwaste at RRC KI territory is shown to be the inevitable result of Institute's activity performed in the days of former USSR nuclear weapons project and multiple initial nuclear power projects (performed from 1950's to early 1970's). A characterization of RRC KI temporary radwaste disposal site is given. Described is the system of radiation control and monitoring as implemented on this site. A potential hazard of adverse impacts on the environment and population of the nearby housing area is noted, which is due to possible spread of the radioactive plume by subsoil waters. A description of the concept and project of the RRC KI temporary radwaste disposal site is presented. Specific nature of the activities planned and performed stems from the nearness of housing area. This paper describes main stages of the planned activities for rehabilitation, their expected terms and sources of funding, as well as current status of the project advancement. Outlined are the problems faced in the performance and planning of works. The latter include: diagnostics of the concrete-grouted repositories, dust-suppression technologies, packaging of the fragmented ILW and HLW, soil clean-up, radioactive plume spread prevention, broad radiation monitoring of the work zone and environment in the performance of rehabilitation works. Noted is the intention of RRC KI to establish cooperation with foreign, first of all, the U.S. partners for the solution of problems mentioned above.

  5. Effects of temperature and soil components on emissions from pyrolysis of pyrene-contaminated soil.

    PubMed

    Risoul, Véronique; Richter, Henning; Lafleur, Arthur L; Plummer, Elaine F; Gilot, Patrick; Howard, Jack B; Peters, William A

    2005-11-11

    Effects of temperature and soil on yields and identities of light gases (H2, CH4, C2H2, C2H4, C2H6, CO, and CO2) and polycyclic aromatic hydrocarbons (PAH) from thermal treatment of a pyrene-contaminated (5 wt%) soil in the absence of oxygen were determined for a U.S. EPA synthetic soil matrix prepared to proxy U.S. Superfund soils. Shallow piles (140-170 mg) of contaminated soil particles and as controls, neat (non-contaminated) soil (140-160 mg), neat pyrene (10-15 mg), neat sand (230 mg), and pyrene-contaminated sand (160 mg), were heated in a ceramic boat inside a 1.65 cm i.d. pyrex tube at temperatures from 500 to 1100 degrees C under an axial flow of helium. Volatile products spent 0.2-0.4s at temperature before cooling. Light gases, PAH and a dichloromethane extract of the residue in the ceramic boat, were analyzed by gas chromatography or high pressure liquid chromatography (HPLC). Over 99% pyrene removal was observed when heating for a few tens of seconds in all investigated cases, i.e., at 500, 650, 750, 1000, and 1100 degrees C for soil, and 750 and 1000 degrees C for sand. However, each of these experiments gave significant yields (0.2-16 wt% of the initial pyrene) of other PAH, e.g., cyclopenta[cd]pyrene (CPP), which mutates bacterial cells and human cells in vitro. Heating pyrene-polluted soil gave pyrene conversions and yields of acetylene, CPP, and other PAH exceeding those predicted from similar, but separate heating of neat soil and neat pyrene. Up to 750 degrees C, recovered pyrene, other PAH, and light gases accounted for all or most of the initial pyrene whereas at 1000 and 1100 degrees C conversion to soot was significant. A kinetic analysis disentangled effects of soil-pyrene interactions and vapor phase pyrolysis of pyrene. Increase of residence time was found to be the main reason for the enhanced conversion of pyrene in the case of the presence of a solid soil or sand matrix. Light gas species released due to the thermal treatment, such as

  6. Accumulation of heavy metals from contaminated soil to plants and evaluation of soil remediation by vermiculite.

    PubMed

    Malandrino, Mery; Abollino, Ornella; Buoso, Sandro; Giacomino, Agnese; La Gioia, Carmela; Mentasti, Edoardo

    2011-01-01

    We evaluated the distribution of 15 metal ions, namely Al, Cd, Cu, Cr, Fe, La, Mn, Ni, Pb, Sc, Ti, V, Y, Zn and Zr, in the soil of a contaminated site in Piedmont (Italy). This area was found to be heavily contaminated with Cu, Cr and Ni. The availability of these metal ions was studied using Tessier's sequential extraction procedure: the fraction of mobile species, which potentially is the most harmful for the environment, was much higher than that normally present in unpolluted soils. This soil was hence used to evaluate the effectiveness of treatment with vermiculite to reduce the availability of the pollutants to two plants, Lactuca sativa and Spinacia oleracea, by pot experiments. The results indicated that the addition of vermiculite significantly reduces the uptake of metal pollutants by plants, confirming the possibility of using this clay in amendment treatments of metal-contaminated soils. The effect of plant growth on metal fractionation in soils was investigated. Finally, the sum of the metal percentages extracted into the first two fractions of Tessier's protocol was found to be suitable in predicting the phytoavailability of most of the pollutants present in the investigated soil. PMID:21055788

  7. Subchronic exposure of mice to Love Canal soil contaminants.

    PubMed

    Silkworth, J B; McMartin, D N; Rej, R; Narang, R S; Stein, V B; Briggs, R G; Kaminsky, L S

    1984-04-01

    The health hazard potential of soil collected from the surface of the Love Canal chemical dump site in Niagara Falls, New York, was assessed in 90-day exposure studies. Female CD-1 mice were exposed to two concentrations of the volatile components of 1 kg of soil with and without direct soil contact. Control mice were identically housed but without soil. The soil was replaced weekly and 87 compounds were detected in the air in the cages above fresh and 7-day-old soil as analyzed by gas chromatography/mass spectrometry. The concentration of many of these compounds decreased during the 7-day exposure cycle. Histopathologic, hematologic, and serum enzyme studies followed necropsy of all mice. There was no mortality of mice exposed for up to 90 days under any condition. Thymus and spleen weights relative to body weight were increased after 4 weeks of exposure by inhalation but not after 8 or 12 weeks of exposure. alpha-, beta-, and delta- Benzenehexachlorides , pentachlorobenzene, and hexachlorobenzene were detected in liver tissue from these animals. Mice exposed to 5- to 10-fold elevated concentration of volatiles had increased body and relative kidney weights. There was no chemically induced lesion in any animal exposed only to the volatile soil contaminants. Mice exposed by direct contact with the soil without elevated volatile exposure had increased body (10%) and relative liver weights (169%). Centrolobular hepatocyte hypertrophy, which involved 40 to 70% of the lobules, was observed in all mice in this group.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6724196

  8. Development and Performance Assessment of Soil Washing Equipment for Soil Contaminated with Radionuclide

    SciTech Connect

    Gye-Nam Kim; Jei-Kwon Moon; Chong-Hun Jung

    2007-07-01

    The purpose of this study is to develop a soil washing system and to define the most suitable experimental conditions for the individual elemental equipment in a soil washing system for decontaminating the radioactive soil from around a TRIGA (Training, Research, Isotope, General Atomic) reactor in Korea. Analysis results have shown that the main radionuclides were Cs{sup 137} and Co{sup 60}, the soil particle size ranges from 0.063 mm to 1.0 mm and the radioactive concentration was the strongest in a soil particle smaller than 0.063 mm as predicted. Meanwhile, an oxalic acid was found to be the most efficient chemical agent for washing, especially of cobalt. The scrubbing time of four hours was an optimum time to obtain a removal efficiency of more than 75% for {sup 137}Cs and {sup 60}Co. A mixing ratio of the soil weight to the volume of the oxalic acid solution, 1:10, was observed to be the best for a washing and it was estimated to be reasonable for 2 cycles of a scrubbing with 1.0 M of oxalic acid to avoid a generation of an excessive waste-solution. (authors)

  9. Risk assessment based on current release standards for radioactive surface contamination

    SciTech Connect

    Chen, S.Y.

    1993-09-01

    Standards for uncontrolled releases of radioactive surface contamination have been in existence in the United States for about two decades. Such standards have been issued by various agencies, including the US Department of Energy. This paper reviews the technical basis of published standards, identifies areas in need of revision, provides risk interpretations based on current technical knowledge and the regulatory environment, and offers suggestions for improvements.

  10. Effect of soil texture on phytoremediation of arsenic-contaminated soils

    NASA Astrophysics Data System (ADS)

    Pallud, C. E.; Matzen, S. L.; Olson, A.

    2015-12-01

    Soil arsenic (As) contamination is a global problem, resulting in part from anthropogenic activities, including the use of arsenical pesticides and treated wood, mining, and irrigated agriculture. Phytoextraction using the hyperaccumulating fern Pteris vittata is a promising new technology to remediate soils with shallow arsenic contamination with minimal site disturbance. However, many challenges still lie ahead for a global application of phytoremediation. For example, remediation times using P. vittata are on the order of decades. In addition, most research on As phytoextraction with P. vittata has examined As removal from sandy soils, where As is more available, with little research focusing on As removal from clayey soils, where As is less available. The objective of this study is to determine the effects of soil texture and soil fertilization on As extraction by P. vittata, to optimize remediation efficiency and decrease remediation time under complex field conditions. A field study was established 2.5 years ago in an abandoned railroad grade contaminated with As (average 85.5 mg kg-1) with texture varying from sandy loam to silty clay loam. Organic N, inorganic N, organic P, inorganic P, and compost were applied to separate sub-plots; control ferns were grown in untreated soil. In a parallel greenhouse experiment, ferns were grown in sandy loam soil extracted from the field (180 mg As kg-1), with similar treatments as those used at the field site, plus a high phosphate treatment and treatments with arbuscular mycorrhizal fungi. In the field study, fern mortality was 24% higher in clayey soil than in sandy soil due to waterlogging, while As was primarily associated with sandy soil. Results from the sandy loam soil indicate that soil treatments did not significantly increase As phytoextraction, which was lower in phosphate-treated ferns than in control ferns, both in the field and greenhouse study. Under greenhouse conditions, ferns treated with organic N were

  11. Sodium hypochlorite oxidation of petroleum aliphatic contaminants in calcareous soils.

    PubMed

    Picard, François; Chaouki, Jamal

    2016-02-01

    This research project investigated the sodium hypochlorite (NaClO) oxidation of aliphatic petroleum contaminants (C10-C50) in a calcareous soil (average 5473 ppm C10-C50, 15 wt% Ca), which had been excavated from a contaminated industrial site. The decontamination objective was to lower the C10-C50 concentration to 700 ppm. CO2 acidity was used in the project to boost the NaClO oxidation yield and seems to have played a role in desorbing the natural organic matter. The experimental conditions were a 2- to 16-h reaction time, at room temperature, with a 1 to 12.5 wt% NaClO oxidative solution and a fixed 2:1 solution-to-soil ratio. With a 3 wt% NaClO solution and with a CO2 overhead, the NaClO dosage requirement was maintained below 60 g NaClO/g of oxidized C10-C50 over the entire decontamination range. The strong chlorine smell remaining after the reaction was completed suggests that part of the NaClO requirement can be recycled. Except traces of chloroform, there were no regulation-listed organochloride contaminants detected on either the treated soil samples or leachates and the total count of chlorinated compounds in treated soil samples was below the detection limit of 250 mg/kg. The NaClO oxidation mechanism on aliphatic substrates might be triggered by transition metals, such as manganese, but no attempt has been made to investigate the oxidation mechanism. Further investigations would include a constant-fed NaClO system and other techniques to lower the required NaClO dosage. PMID:26702553

  12. Estimated association between dwelling soil contamination and internal radiation contamination levels after the 2011 Fukushima Daiichi nuclear accident in Japan

    PubMed Central

    Tsubokura, Masaharu; Nomura, Shuhei; Sakaihara, Kikugoro; Kato, Shigeaki; Leppold, Claire; Furutani, Tomoyuki; Morita, Tomohiro; Oikawa, Tomoyoshi; Kanazawa, Yukio

    2016-01-01

    Objectives Measurement of soil contamination levels has been considered a feasible method for dose estimation of internal radiation exposure following the Chernobyl disaster by means of aggregate transfer factors; however, it is still unclear whether the estimation of internal contamination based on soil contamination levels is universally valid or incident specific. Methods To address this issue, we evaluated relationships between in vivo and soil cesium-137 (Cs-137) contamination using data on internal contamination levels among Minamisoma (10–40 km north from the Fukushima Daiichi nuclear power plant), Fukushima residents 2–3 years following the disaster, and constructed three models for statistical analysis based on continuous and categorical (equal intervals and quantiles) soil contamination levels. Results A total of 7987 people with a mean age of 55.4 years underwent screening of in vivo Cs-137 whole-body counting. A statistically significant association was noted between internal and continuous Cs-137 soil contamination levels (model 1, p value <0.001), although the association was slight (relative risk (RR): 1.03 per 10 kBq/m2 increase in soil contamination). Analysis of categorical soil contamination levels showed statistical (but not clinical) significance only in relatively higher soil contamination levels (model 2: Cs-137 levels above 100 kBq/m2 compared to those <25 kBq/m2, RR=1.75, p value <0.01; model 3: levels above 63 kBq/m2 compared to those <11 kBq/m2, RR=1.45, p value <0.05). Conclusions Low levels of internal and soil contamination were not associated, and only loose/small associations were observed in areas with slightly higher levels of soil contamination in Fukushima, representing a clear difference from the strong associations found in post-disaster Chernobyl. These results indicate that soil contamination levels generally do not contribute to the internal contamination of residents in Fukushima; thus, individual

  13. Copper removal from contaminated soils by soil washing process using camellian-derived saponin

    NASA Astrophysics Data System (ADS)

    Reyes, Arturo; Fernanda Campos, Maria; Videla, Álvaro; Letelier, María Victoria; Fuentes, Bárbara

    2015-04-01

    Antofagasta Region in North of Chile has been the main copper producer district in the world. As a consequence of a lack of mining closure regulation, a large number of abandon small-to-medium size metal-contaminated sites have been identified in the last survey performed by the Chilean Government. Therefore, more research development on sustainable reclamation technologies must be made in this extreme arid-dry zone. The objective of this study is to test the effectiveness of soil remediation by washing contaminated soil using camellian-derived saponin for the mobilization of copper. Soil samples were taken from an abandoned copper mine site located at 30 km North Antofagasta city. They were dried and sieved at 75 µm for physico-chemical characterization. A commercial saponin extracted from camellias seed was used as biosurfactant. The soil used contains 67.4 % sand, 26.3 % silt and 6.3 % clay. The soil is highly saline (electric conductivity, 61 mScm-1), with low organic matter content (0.41%), with pH 7.30, and a high copper concentration (2200 mg Kg-1 soil). According to the sequential extraction procedure of the whole soil, copper species are mainly as exchangeable fraction (608.2 mg Kg-1 soil) and reducible fraction (787.3 mg Kg-1 soil), whereas the oxidizable and residual fractions are around 205.7 and 598.8 mg Kg-1 soil, respectively. Soil particles under 75 µm contain higher copper concentrations (1242 mg Kg-1 soil) than the particle fraction over 75 µm (912 mg Kg-1 soil). All washing assays were conducted in triplicate using a standard batch technique with and without pH adjustment. The testing protocols includes evaluation of four solid to liquid ratio (0.5:50; 1.0:50; 2.0:50, and 5.0:50) and three saponin concentrations (0, 1, and 4 mg L-1). After shaking (24 h, 20±1 °C) and subsequently filtration (0.45 µm), the supernatants were analyzed for copper and pH. The removal efficiencies of copper by saponin solutions were calculated in according to the

  14. Electroslag Remelting (ESR) Slags for Removal of Radioactive Oxide Contaminants from Stainless Steels

    SciTech Connect

    Chernicoff, W.P.; Chou, K.C.; Gao, H.; MacDonald, C.J.; Molecke, M.A.; Pal, U.B.; Van Den, J.; Woolley, D.

    1999-06-30

    Downsizing and decommissioning of nuclear operations is increasing the stockpile of Radioactive Scrap Metal (RSM). It is estimated that the annual generation of RSM for the entire DOE complex will be approximately 120,000 metric tons beginning in the year 2000. Out of which contaminated stainless steel with high chromium and nickel contents constitutes 25-30 wt. % [1]. Disposal of this material not only represents resource and value lost, but also necessitates long term monitoring for environmental compliance. The latter results in additional recurring expense. Therefore, it is desirable to be able to decontaminate the radioactive stainless steel to a satisfactory level that can be recycled or at least used for fabrication of containers for RSM disposal instead of using virgin stainless steel. Decontamination of radioactive stainless steel using the ESR process is investigated. In this paper the relevant slag properties, capacity to incorporate the radioactive contaminant, slag-metal partition coefficient, volatilization rate, volatile species, viscosity, electrical conductivity and surface tension are presented as a function of temperature. The impact of these properties on the ESR decontamination process is discussed.

  15. A Review of Removable Surface Contamination on Radioactive Materials Transportation Containers

    SciTech Connect

    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.

  16. Radioactive contamination of the Balchug (Upper Yenisey) floodplain, Russia in relation to sedimentation processes and geomorphology.

    PubMed

    Linnik, V G; Brown, J E; Dowdall, M; Potapov, V N; Surkov, V V; Korobova, E M; Volosov, A G; Vakulovsky, S M; Tertyshnik, E G

    2005-03-01

    The radioactive contamination of a riverine floodplain, heavily influenced by discharges from Krasnoyarsk-26, has been studied with respect to sedimentation processes and the geomorphology of the Upper Yenisey floodplain. The study was effected by implementation of a regime of in situ observations and measurements, sampling, and the interpretation of satellite images. The results of the study indicate that on the Balchug Bypass Floodplain, radionuclide contamination is primarily influenced by the thickness of the deposited sediments, and the area can be considered as two depositional environments. The Balchug floodplain area was contaminated due to sedimentation of radionuclide-contaminated alluvium, whose depositional regime significantly changed after the construction of a hydroelectric power station in 1967. Contamination levels are lower on the upstream part of the floodplain where sediment depth is less than 0.2-0.3 m, and this contamination started to accumulate in 1967, while the downstream part of the floodplain, exhibiting deeper deposits, displays higher levels of radionuclide contamination because radionuclides began to deposit here in 1958 when the Krasnoyarsk-26 Mining and Chemical Combine (KMCC) commenced operation. Radionuclide contamination of the floodplain is also related to the elevation of the floodplain, higher regions of the floodplain typically having lower contamination than low-lying areas, which tend to be frequently inundated with sediments being deposited during such inundations. Local relief, its orientation, and vegetation cover have also combined to form sediment traps with significantly higher radionuclide contamination. Lithological analysis combined with radiometric assay indicates a total 137Cs floodplain inventory of 33.7 GBq. PMID:15740772

  17. APPROACHES FOR REMEDIATION OF FEDERAL FACILITY SITES CONTAMINATED WITH EXPLOSIVE/RADIOACTIVE WASTE

    EPA Science Inventory

    Military operations have resulted in the contamination of soil and ground water at many federal facility sites. everal of these sites are undergoing corrective action to reduce risk. his handbook covers safety concerns, sampling methods, and treatment and management options for e...

  18. Remediation of hexachlorobenzene contaminated soils by rhamnolipid enhanced soil washing coupled with activated carbon selective adsorption.

    PubMed

    Wan, Jinzhong; Chai, Lina; Lu, Xiaohua; Lin, Yusuo; Zhang, Shengtian

    2011-05-15

    The present study investigates the selective adsorption of hexachlorobenzene (HCB) from rhamnolipid solution by a powdered activated carbon (PAC). A combined soil washing-PAC adsorption technique is further evaluated on the removal of HCB from two soils, a spiked kaolin and a contaminated real soil. PAC at a dosage of 10 g L(-1) could achieve a HCB removal of 80-99% with initial HCB and rhamnolipid concentrations of 1 mg L(-1) and 3.3-25 g L(-1), respectively. The corresponding adsorptive loss of rhamnolipid was 8-19%. Successive soil washing-PAC adsorption tests (new soil sample was subjected to washing for each cycle) showed encouraging leaching and adsorption performances for HCB. When 25 g L(-1) rhamnolipid solution was applied, HCB leaching from soils was 55-71% for three cycles of washing, and HCB removal by PAC was nearly 90%. An overall 86% and 88% removal of HCB were obtained for kaolin and real soil, respectively, by using the combined process to wash one soil sample for twice. Our investigation suggests that coupling AC adsorption with biosurfactant-enhanced soil washing is a promising alternative to remove hydrophobic organic compounds from soils. PMID:21397398

  19. REMEDIATION OF SOILS CONTAMINATED WITH WOOD-TREATMENT CHEMICALS (PCP AND CREOSOTE)

    EPA Science Inventory

    PCP and creosote PAHs are found in most of the contaminated soils at wood-treatment sites. The treatment methods currently being used for such soils include soil washing, incineration, and biotreatment. Soil washing involves removal of the hazardous chemicals from soils ...

  20. Enhancement of bioremediation of a creosote-contaminated soil

    SciTech Connect

    Carriere, P.P.E.; Mesania, F.A.

    1995-12-31

    There is a growing concern in the US about the increasing number of industrial sites containing concentration of polynuclear aromatic hydrocarbons (PAHs) in their soil and waste sludge above background levels. PAHs, neutral and non-polar organic compounds, consist of two or more fused benzene rings which are generated from industrial activities such as creosote wood treating, gas manufacturing, coke making, coal tar refining, petroleum refining, and aluminum smelting. Low molecular weight PAHs are generally considered as extremely toxic compounds, whereas the higher molecular weight PAHs are carcinogenic in nature. Bioremediation, a viable option for treatment of PAHs contaminated soil, can be enhanced by the use of surfactant. In this study a nonionic surfactant Triton X-100, was investigated. Abiotic soil desorption experiments were performed to determine the kinetics of release of selected PAH compounds from the soil matrix to the aqueous phase. Respirometric experiments were also conducted to evaluate the effect of nonionic surfactant on biodegradation. The N-Con system respirometer was used to monitor the oxygen uptake by the microorganisms. The abiotic experiments results indicated that the addition of surfactant to soil/water systems increases the desorption of PAH compounds. The increase in PAHs availability to the microorganisms produced an increase in oxygen uptake.

  1. Risk of antibiotic resistance from metal contaminated soils

    NASA Astrophysics Data System (ADS)

    Knapp, Charles

    2013-04-01

    It is known that contaminated soils can lead to increased incidence of illness and disease, but it may also prevent our ability to fight disease. Many antibiotic resistant genes (ARG) acquired by bacteria originate from the environment. It is important to understand factors that influence levels of ARG in the environment, which could affect us clinically and agriculturally. The presence of elevated metal content in soils often promotes antibiotic resistance in exposed microorganisms. Using qPCR, the abundances of ARG to compare levels with geochemical conditions in randomly selected soils from several countries. Many ARG positively correlated with soil metal content, especially copper, chromium, nickel, lead, and iron. Results suggest that geochemical metal conditions influence the potential for antibiotic resistance in soil, which might be used to estimate baseline gene presence on various landscape scales and may translate to epidemiological risk of antibiotic-resistance transmission from the environment. This suggests that we may have to reconsider tolerances of metal pollution in the environment.

  2. Toxicity Assessment of Contaminated Soils of Solid Domestic Waste Landfill

    NASA Astrophysics Data System (ADS)

    Pasko, O. A.; Mochalova, T. N.

    2014-08-01

    The paper delivers the analysis of an 18-year dynamic pattern of land pollutants concentration in the soils of a solid domestic waste landfill. It also presents the composition of the contaminated soils from different areas of the waste landfill during its operating period. The authors calculate the concentrations of the following pollutants: chrome, nickel, tin, vanadium, lead, cuprum, zinc, cobalt, beryllium, barium, yttrium, cadmium, arsenic, germanium, nitrate ions and petrochemicals and determine a consistent pattern of their spatial distribution within the waste landfill area as well as the dynamic pattern of their concentration. Test-objects are used in experiments to make an integral assessment of the polluted soil's impact on living organisms. It was discovered that the soil samples of an animal burial site are characterized by acute toxicity while the area of open waste dumping is the most dangerous in terms of a number of pollutants. This contradiction can be attributed to the synergetic effect of the polluted soil, which accounts for the regularities described by other researchers.

  3. Stabilization of lead-contaminated soil saves time

    SciTech Connect

    Hasbach, A.

    1995-03-01

    The Wisconsin Department of Transportation (WisDOT) acquired property adjacent to a former battery-cracking facility. The soil contained extremely high levels of lead from past waste disposal activities. The Wisconsin Department of Natural Resources (WDNR) required WisDOT to perform a remedial investigation and take corrective action. WisDOT retained RMT Inc., Madison, Wisc., to do the work. RMT`s investigation discovered lead levels as high as 50,000 mg/kg in the soil. An action level of 500 mg/kg was negotiated with WDNR. A total of 11 acres exceeded this level; 7.5 acres contained lead exceeding 1,000 mg/kg. In some areas, contamination reached a depth of 12 feet, while in others lead was found only in the top 12 inches. A total of 55,000 cubic yards of soil required treatment. A dig and haul approach to remediation would have cost $200 to $300 per ton. Instead, RMT called for in situ treatment using a patented chemical mixture to tie the lead up in a stable and immobile compound. While it does not render the soil lead free, it does prevent the lead from leaching into nearby soil or groundwater.

  4. Rate controlling model for bioremediation of oil contaminated soil

    SciTech Connect

    Li, K.Y.; Annamali, S.N.; Hopper, J.R. )

    1993-11-01

    A mathematical model of bio-remediation of hydrocarbons in a soil matrix has been developed to predict the rate controlling step and the remediation rate during the bioremediation of a contaminated soil. The model is based on mass transfer of oxygen and oil into the aqueous solution in the soil matrix and the biodegradation of the hydrocarbons in the aqueous solution. Monod's equation was used to describe the biodegradation rate in aqueous solution while the mass transfer equations were used to describe the mass transfer rates of oxygen and oil in the soil matrix. Results from model calculations indicate that the bio-remediation rate increases and approaches a limiting value when one of the rates becomes controlling. When the parameters of the site soil samples are measured and the solubilities of oxygen and oil in aqueous solution are obtained, the bioremediation rate can be predicted by this model. The rate controlling step of the bioremediation site may be identified quickly and steps to improve the bioremediation rate can be recommended. 8 refs., 7 figs.

  5. [Effects and Biological Response on Bioremediation of Petroleum Contaminated Soil].

    PubMed

    Yang, Qian; Wu, Man-li; Nie, Mai-qian; Wang, Ting-ting; Zhang, Ming-hui

    2015-05-01

    Bioaugmentation and biostimulation were used to remediate petroleum-contaminated soil which were collected from Zichang city in North of Shaanxi. The optimal bioremediation method was obtained by determining the total petroleum hydrocarbon(TPH) using the infrared spectroscopy. During the bioremediation, number of degrading strains, TPH catabolic genes, and soil microbial community diversity were determined by Most Probable Number (MPN), polymerase chain reaction (PCR) combined agarose electrophoresis, and PCR-denaturing gradient electrophoresis (DGGE). The results in different treatments showed different biodegradation effects towards total petroleum hydrocarbon (TPH). Biostimulation by adding N and P to soils achieved the best degradation effects towards TPH, and the bioaugmentation was achieved by inoculating strain SZ-1 to soils. Further analysis indicated the positive correlation between catabolic genes and TPH removal efficiency. During the bioremediation, the number of TPH and alkanes degrading strains was higher than the number of aromatic degrading strains. The results of PCR-DGGE showed microbial inoculums could enhance microbial community functional diversity. These results contribute to understand the ecologically microbial effects during the bioremediation of petroleum-polluted soil. PMID:26314140

  6. Leaching of Contamination from Stabilization/Solidification Remediated Soils of Different Texture

    NASA Astrophysics Data System (ADS)

    Burlakovs, Juris; Kasparinskis, Raimonds; Klavins, Maris

    2012-09-01

    Development of soil and groundwater remediation technologies is a matter of great importance to eliminate historically and currently contaminated sites. Stabilization/solidification (S/S) refers to binding of waste contaminants to a more chemically stable form and thus diminishing leaching of contamination. It can be performed using cement with or without additives in order to stabilize and solidify soil with the contamination in matrix. A series of experiments were done to determine leaching properties of spiked soils of different texture bound with cement. Results of experiments showed, that soil texture (content of sand, silt and clay particles) affects the leaching of heavy metals from stabilized soils.

  7. Rhizoremediation of phenanthrene and pyrene contaminated soil using wheat.

    PubMed

    Shahsavari, Esmaeil; Adetutu, Eric M; Taha, Mohamed; Ball, Andrew S

    2015-05-15

    Rhizoremediation, the use of the plant rhizosphere and associated microorganisms represents a promising method for the clean up of soils contaminated with polycyclic aromatic hydrocarbons (PAHs) including phenanthrene and pyrene, two model PAHs. Although numerous studies have been published reporting the degradation of phenanthrene and pyrene, very few evaluate the microbial basis of the rhizoremediation process through the application of molecular tools. The aim of this study was to investigate the effect of wheat on the degradation of two model PAHs (alone or in combination) and also on soil bacterial, fungal and nidA gene (i.e. a key gene in the degradation of pyrene) communities. The addition of wheat plants led to a significant enhancement in the degradation of both phenanthrene and pyrene. In pyrene-contaminated soils, the degradation rate increased from 15% (65 mg/kg) and 18% (90 mg/kg) in unplanted soils to 65% (280 mg/kg) and 70% (350 mg/kg) in planted treatments while phenanthrene reduction was enhanced from 97% (394 mg/kg) and 87% (392 mg/kg) for unplanted soils to 100% (406 mg/kg) and 98% (441 mg/kg) in the presence of wheat. PCR-DGGE results showed that the plant root let to some changes in the bacterial and fungal communities; these variations did not reflect any change in hydrocarbon-degrading communities. However, plate counting, traditional MPN and MPN-qPCR of nidA gene revealed that the wheat rhizosphere led to an increase in the total microbial abundance including PAH degrading organisms and these increased activities resulted in enhanced degradation of phenanthrene and pyrene. This clearer insight into the mechanisms underpinning PAH degradation will enable better application of this environmentally friendly technique. PMID:25819570

  8. Mechanisms for surface contamination of soils and bottom sediments in the Shagan River zone within former Semipalatinsk Nuclear Test Site.

    PubMed

    Aidarkhanov, A O; Lukashenko, S N; Lyakhova, O N; Subbotin, S B; Yakovenko, Yu Yu; Genova, S V; Aidarkhanova, A K

    2013-10-01

    The Shagan River is the only surface watercourse within the former Semipalatinsk Test Site (STS). Research in the valley of the Shagan River was carried out to study the possible migration of artificial radionuclides with surface waters over considerable distances, with the possibility these radionuclides may have entered the Irtysh River. The investigations revealed that radioactive contamination of soil was primarily caused by the first underground nuclear test with soil outburst conducted at the "Balapan" site in Borehole 1004. The surface nuclear tests carried out at the "Experimental Field" site and global fallout made insignificant contributions to contamination. The most polluted is the area in the immediate vicinity of the "Atomic" Lake crater. Contamination at the site is spatial. The total area of contamination is limited to 10-12 km from the crater piles. The ratio of plutonium isotopes was useful to determine the source of soil contamination. There was virtual absence of artificial radionuclide migration with surface waters, and possible cross-border transfer of radionuclides with the waters of Shagan and Irtysh rivers was not confirmed. PMID:23811126

  9. Olive mill waste biochar: a promising soil amendment for metal immobilization in contaminated soils.

    PubMed

    Hmid, Amine; Al Chami, Ziad; Sillen, Wouter; De Vocht, Alain; Vangronsveld, Jaco

    2015-01-01

    The potential use of biochar from olive mill waste for in situ remediation of metal contaminated soils was evaluated. Biochar was mixed with metal contaminated soil originating from the vicinity of an old zinc smelter. Soil-biochar mixtures were equilibrated for 30 and 90 days. At these time points, Ca(NO3)2 exchangeable metals were determined, and effects of the biochar amendment on soil toxicity were investigated using plants, bacteria, and earthworms. Bean (Phaseolus vulgaris) growth, metal content, antioxidative enzymes activities, and soluble protein contents were determined. Furthermore, effects on soil microbial communities (activity, diversity, richness) were examined using Biolog ECOplates. After 120 days of soil-biochar equilibration, effects on weight and reproduction of Eisenia foetida were evaluated. With increasing biochar application rate and equilibration period, Ca(NO3)2 exchangeable metals decreased, and growth of bean plants improved; leaf metal contents reduced, the activities of antioxidative stress enzymes decreased, and soluble protein contents increased. Soil microbial activity, richness, and diversity were augmented. Earthworm mortality lowered, and their growth and reproduction showed increasing trends. PMID:25146122

  10. Spectroscopy as a diagnostic tool for urban soil contaminants

    NASA Astrophysics Data System (ADS)

    Brook, Anna; Kopel, Daniella

    2014-05-01

    Urbanization has become one of the major forces of change around the globe. Land use transformation, especially urbanization has the most profound influences of human activities because it affects so many of the planet's physical and biological systems. Land use changes directly impact the ability of the earth to continue to provide ecological services to human society and the other occupants of the ecosystems. The urban process gradually degrades and transforms agricultural and natural ecosystems into built environments. The urban environment includes cities, suburbs, peri-urban areas and towns. Urban ecosystems are highly heterogeneous due to the variety of land covers and land purposes. Thus, the choices on managing the extent and arranging the land cover patches (e.g., lawns) assist to shape the emergent structure and function of the urban ecosystems. As a result of ecological conditions and current management status the urban soils show substantial spatial heterogeneity. Whereas, adverse effects of pollutants on ecosystems have been demonstrated, one important need for environmental impact assessment have been defined as maintenance of long-term monitoring systems, which can enable to improve monitoring, modelling and assessment of various stressors in agriculture environment. Diffuse reflectance spectroscopy and diffuse reflectance Fourier-transform infrared (FTIR) spectroscopy across visible-near- short- mid- and long- wave infrared (0.4-14μm) has the potential to meet this demand. Relationships between spectral reflectance and soil properties, such as grain size distribution, moisture, iron oxides, carbonate content, and organic matter, have already been established in many studies (Krishnan et al. 1980, Ben-Dor and Banin 1995, Jarmer et al. 2008, Richter et al. 2009). The aims of this study are to develop diagnostic tool for heavy metals, polycyclic aromatic hydrocarbons, asbestos and other anthropogenic contaminants in urban soil using spectroscopy

  11. Phytoremediation`s role in bioremediation of recalcitrant soil contaminants

    SciTech Connect

    Fletcher, J.S.

    1995-12-31

    Flavonoid and coumarin compounds produced by plants supported the growth of polychlorinated biphenyl (PCB)-degrading bacteria, and the bacteria retained their PCB-degrading properties. Root leachates and washings from mulberry trees also supported the growth of a PCB-degrading bacterium. The release of phenolics into the soil by the network of finely separated plant roots may be thought of as a naturally occurring injection system capable of delivering desired substrates into the soil that fosters the growth and action of PCB-degrading bacteria. However, it is important to recognize that the roots of all plant species do not produce and release equal amounts and kinds of phenolic compounds; therefore, the rhizosphere zone of all plants must not be considered a haven for PCB-degrading bacteria. It may be that only a few plant species have the desired characteristics. Awareness of such species would be extremely valuable, because growing such plants at contaminated sites has the potential of selectively fostering the growth of PCB-degrading bacteria over competing organisms. The outcome could be a sustained population of PCB-degrading bacteria that would degrade PCBs over an extended time period. Plant-microbe systems have the potential of providing inexpensive, ecologically stable bioremediation systems, and thereby play a major role in bioremediation of recalcitrant soil contaminants.

  12. Microbial mobilization of plutonium and other actinides from contaminated soil.

    PubMed

    Francis, A J; Dodge, C J

    2015-12-01

    We examined the dissolution of Pu, U, and Am in contaminated soil from the Nevada Test Site (NTS) due to indigenous microbial activity. Scanning transmission x-ray microscopy (STXM) analysis of the soil showed that Pu was present in its polymeric form and associated with Fe- and Mn- oxides and aluminosilicates. Uranium analysis by x-ray diffraction (μ-XRD) revealed discrete U-containing mineral phases, viz., schoepite, sharpite, and liebigite; synchrotron x-ray fluorescence (μ-XRF) mapping showed its association with Fe- and Ca-phases; and μ-x-ray absorption near edge structure (μ-XANES) confirmed U(IV) and U(VI) oxidation states. Addition of citric acid or glucose to the soil and incubated under aerobic or anaerobic conditions enhanced indigenous microbial activity and the dissolution of Pu. Detectable amount of Am and no U was observed in solution. In the citric acid-amended sample, Pu concentration increased with time and decreased to below detection levels when the citric acid was completely consumed. In contrast, with glucose amendment, Pu remained in solution. Pu speciation studies suggest that it exists in mixed oxidation states (III/IV) in a polymeric form as colloids. Although Pu(IV) is the most prevalent and generally considered to be more stable chemical form in the environment, our findings suggest that under the appropriate conditions, microbial activity could affect its solubility and long-term stability in contaminated environments. PMID:26406590

  13. Humic substances-enhanced electroremediation of heavy metals contaminated soil.

    PubMed

    Bahemmat, Mahdi; Farahbakhsh, Mohsen; Kianirad, Mehran

    2016-07-15

    The effects of catholyte conditioning and the use of humic acids (HAs) and fulvic acids (FAs) as chelating agents to improve electrokinetic (EK) remediation efficiency were investigated using a real and highly contaminated soil. By applying a constant voltage (2.0V/cm) to the soil, pH and current changes and heavy metals (HMs) concentration were investigated through a range of durations and positions. The observations demonstrated that both catholyte conditioning with 0.1N HNO3 and using humic substances (HSs) enhance remediation efficiency. After 20 days of EK treatment, the removal efficiency of HMs in HS-enhanced EK remediation was about 2.0-3.0 times greater than when unenhanced. The quantity of HMs moving toward the cathode exceeded the anode, from which it could be reasonably inferred that most negatively charged HM-HS complexes were moved by electroosmotic forces. Further, free HM cations and positively charged complexed HMs migrated to the catholyte compartment by electromigration. The results obtained in this study, demonstrate the suitability of HS-enhanced EK remediation in HMs contaminated soil. PMID:27058638

  14. Effect of oxygen amendments and soil pH on bioremediation of industrially contaminated soils

    SciTech Connect

    Joshi, M.M.; Lee, S.

    1996-04-01

    Polynuclear aromatic hydrocarbons (PAHs), by-products of coal conversion processes, have contaminated soils near coal plant sites either through accidental spills or systematic discharge. Because these compounds are carcinogenic, mutagenic, and teratogenic, remediation of such sites is a legitimate concern. For this study, contaminated soil samples were obtained from the Alberta Research Council (ARC) primary clean-up facility. Preliminary analysis of the soil was done for contaminant characterization and determination of initial contamination levels. Acinetobacter sp. was used for aerobic treatment of soil over a five-week period under optimum conditions. Because the rate of biodegradation is influenced by the pH, it is of interest to study the effect of pH on remediation efficiency in the physiological pH range of 5.0 to 9.0. Also, oxygen amendment via hydrogen peroxide solution was used to improve remediation in a packed bed, and the results were compared with those obtained under completely mixed conditions.

  15. Arsenic and chromium speciation in an urban contaminated soil.

    PubMed

    Landrot, Gautier; Tappero, Ryan; Webb, Samuel M; Sparks, Donald L

    2012-08-01

    The distribution and speciation of As and Cr in a contaminated soil were studied by synchrotron-based X-ray microfluorescence (μ-XRF), microfocused X-ray absorption spectroscopy (μ-XAS), and bulk extended X-ray absorption fine structure spectroscopy (EXAFS). The soil was taken from a park in Wilmington, DE, which had been an important center for the leather tanning industry along the Atlantic seaboard of the United States, until the early 20th century. Soil concentrations of As, Cr, and Pb measured at certain locations in the park greatly exceeded the background levels of these heavy metals in the State of Delaware. Results show that Cr(III) and As(V) species are mainly present in the soil, with insignificant amounts of Cr(VI) and As(III). Micro-XRF maps show that Cr and Fe are distributed together in regions where their concentrations are diffuse, and at local spots where their concentrations are high. Iron oxides, which can reduce Cr(VI) to Cr(III), are present at some of these hot spots where Cr and Fe are highly concentrated. Arsenic is mainly associated with Al in the soil, and to a minor extent with Fe. Arsenate may be sorbed to aluminum oxides, which might have transformed after a long period of time into an As-Al precipitate phase, having a structure and chemical composition similar to mansfieldite (AlAsO(4)⋅2H(2)O). The latter hypothesis is supported by the fact that only a small amount of As present in the soil was desorbed using the characteristic toxicity leaching procedure tests. This suggests that As is immobilized in the soil. PMID:22520924

  16. Land contamination and soil evolution in abandoned mine areas (Italy)

    NASA Astrophysics Data System (ADS)

    Bini, Claudio; Wahsha, Mohammad; Spiandorello, Massimo

    2014-05-01

    In Italy ore research and exploitation are nearly exhausted since the end of the last century, leaving on the land a huge amount of mine waste, therefore provoking evident environmental damage including landscape, vegetation and the food chain, and a potential threat to human health. The increasing environmental consciousness of general population compelled Public Administrators to set down effective legislation acts on this subject (e.g. D.L. 152/2006), and more generally on environmental contamination. In this work we present the results of a survey carried out at several mixed sulphides mine sites in Italy, exploited for at least a millennium, and closed in the '60s of the last century. Biogeochemical analyses carried out on 50 soil profiles (mostly Entisols and Inceptisols) and vegetation in the proximal and distal areas of ore exploitation show metal concentrations overcoming legislation limits on average (Cu up to 3160 mg kg-1 , Pb up to 23600 mg kg-1, Zn up to 1588 mg kg-1, Fe up to 52,30 %). Ni, Cr and Mn concentrations, instead, are generally below the reference levels. Metal concentrations in native vegetation of the examined areas are moderately to highly elevated. Significant amounts of Cu, Pb, Zn in roots of Plantago major and Silene dioica, in leaves of Taraxacum officinale, and Salix spp, have been recorded. Essential elements, in particular, present Translocation Coefficients (TC) >1, with Mn>Zn>Cu>Fe. Toxic elements (Cd, Cr, Pb), instead, present TC<1, suggesting a synergic/antagonist effect to occur among metals and plants, according to their role in mineral nutrition. The results obtained suggest the abandoned mine sites to represent actual natural aboratories where to experiment new opportunities for restoration of anthropogenically contaminated areas, and to study new pedogenetic trends from these peculiar parent materials. Moreover, the examined plants are genetically adapted to naturally metal-enriched soils, and therefore may be utilized in

  17. Application, chemistry, and environmental implications of contaminant-immobilization amendments on agricultural soil and water quality.

    PubMed

    Udeigwe, Theophilus K; Eze, Peter N; Teboh, Jasper M; Stietiya, Mohammed H

    2011-01-01

    Contaminants such as nitrogen (N), phosphorus (P), dissolved organic carbon (DOC), arsenic (As), heavy metals, and infectious pathogens are often associated with agricultural systems. Various soil and water remediation techniques including the use of chemical amendments have been employed to reduce the risks associated with these contaminants. This paper reviews the use of chemical amendments for immobilizing principal agricultural contaminants, the chemistry of contaminant immobilization, and the environmental consequences associated with the use of these chemical products. The commonly used chemical amendments were grouped into aluminum-, calcium-, and iron-containing products. Other products of interest include phosphorus-containing compounds and silicate clays. Mechanisms of contaminant immobilization could include one or a combination of the following: surface precipitation, adsorption to mineral surfaces (ion exchange and formation of stable complexes), precipitation as salts, and co-precipitation. The reaction pH, redox potential, clay minerals, and organic matter are potential factors that could control contaminant-immobilization processes. Reviews of potential environmental implications revealed that undesirable substances such as trace elements, fluoride, sulfate, total dissolved solids, as well as radioactive materials associated with some industrial wastes used as amendment could be leached to ground water or lost through runoff to receiving water bodies. The acidity or alkalinity associated with some of the industrial-waste amendments could also constitute a substantial environmental hazard. Chemical amendments could introduce elements capable of inducing or affecting the activities of certain lithotrophic microbes that could influence vital geochemical processes such as mineral dissolution and formation, weathering, and organic matter mineralization. PMID:20832118

  18. APPLICATION OF STEAM INJECTION/VACUUM EXTRACTION TREATMENT SYSTEMS TO CONTAMINATED SOILS

    EPA Science Inventory

    Steam Injection/Vacuum Extraction (SIVE) is a method to enable vacuum extraction to treat soils contaminated with semivolatile organic compounds (SVOCS) and to speed the cleanup of soils contaminated with volatile organic compounds (VOCs). he steam injection raises the soil tempe...

  19. Assessing the bioavailability and risk from metal contaminated soils and dusts#

    EPA Science Inventory

    Exposure to contaminated soil and dust is an important pathway in human and ecological risk assessment and often is the "risk-driver" for metal contaminated soil. Site-specific soil physical and chemical characteristics, as well as biological factors, determine the bioavailabilit...

  20. RISK ASSESSMENT AND REMEDIATION OF SOILS CONTAMINATED BY MINING AND SMELTING OF LEAD, ZINC AND CADMIUM

    EPA Science Inventory

    Mining nd smelting of Pb, Zn and Cd ores have caused widespread soil contamination in many countries. In locations with severe soil contamination, and strongly acidic soil or mine waste, ecosystems are devastated. Research has shown that An phytotoxicity, Pb-induced phosphate def...

  1. ON-SITE ENGINEERING REPORT FOR THE LOW-TEMPERATURE THERMAL DESORPTION PILOT-SCALE TEST ON CONTAMINATED SOIL

    EPA Science Inventory

    Performance of the thermal desorption process for removal of organic contaminants, mostly polynuclear aromatic hydrocarbons (PAHs), from soils was evaluated. The Superfund Site soil tested was a fine sandy soil contaminated with creosote. An optimum operating temperature of 550 C...

  2. ON-SITE ENGINEERING REPORT FOR THE LOW-TEMPERATURE THERMAL DESORPTION PILOT-SCALE TEST ON CONTAMINATED SOIL

    EPA Science Inventory

    Performance of the thermal desorption process for removal of organic contaminants, mostly polynuclear aromatic hydrocarbons (PAHs), from soils was evaluated. he Superfund Site soil tested was a fine sandy soil contaminated with creosote. n optimum operating temperature of 550 deg...

  3. Helium leak testing of a radioactive contaminated vessel under high pressure in a contaminated environment

    SciTech Connect

    Winter, M.E.

    1996-10-01

    At ANL-W, with the shutdown of EBR-II, R&D has evolved from advanced reactor design to the safe handling, processing, packaging, and transporting spent nuclear fuel and nuclear waste. New methods of processing spent fuel rods and transforming contaminated material into acceptable waste forms are now in development. Storage of nuclear waste is a high interest item. ANL-W is participating in research of safe storage of nuclear waste, with the WIPP (Waste Isolation Pilot Plant) site in New Mexico the repository. The vessel under test simulates gas generated by contaminated materials stored underground at the WIPP site. The test vessel is 90% filled with a mixture of contaminated material and salt brine (from WIPP site) and pressurized with N2-1% He at 2500 psia. Test acceptance criteria is leakage < 10{sup -7} cc/seconds at 2500 psia. The bell jar method is used to determine leakage rate using a mass spectrometer leak detector (MSLD). The efficient MSLD and an Al bell jar replaced a costly, time consuming pressure decay test setup. Misinterpretation of test criterion data caused lengthy delays, resulting in the development of a unique procedure. Reevaluation of the initial intent of the test criteria resulted in leak tolerances being corrected and test efficiency improved.

  4. [Biological treatments for contaminated soils: hydrocarbon contamination. Fungal applications in bioremediation treatment].

    PubMed

    Martín Moreno, Carmen; González Becerra, Aldo; Blanco Santos, María José

    2004-09-01

    Bioremediation is a spontaneous or controlled process in which biological, mainly microbiological, methods are used to degrade or transform contaminants to non or less toxic products, reducing the environmental pollution. The most important parameters to define a contaminated site are: biodegradability, contaminant distribution, lixiviation grade, chemical reactivity of the contaminants, soil type and properties, oxygen availability and occurrence of inhibitory substances. Biological treatments of organic contaminations are based on the degradative abilities of the microorganisms. Therefore the knowledge on the physiology and ecology of the biological species or consortia involved as well as the characteristics of the polluted sites are decisive factors to select an adequate biorremediation protocol. Basidiomycetes which cause white rot decay of wood are able to degrade lignin and a variety of environmentally persistent pollutants. Thus, white rot fungi and their enzymes are thought to be useful not only in some industrial process like biopulping and biobleaching but also in bioremediation. This paper provides a review of different aspects of bioremediation technologies and recent advances on ligninolytic metabolism research. PMID:15709784

  5. SAFETY ASPECTS RELATED TO THE RADIOACTIVELY CONTAMINATED FOREST AREAS IN BELARUS

    SciTech Connect

    SULLIVAN,T.; GIBBS,B.; ANDERSSON,K.G.; ROED,J.; RYMKEVICH,V.; BREKKE,D.

    1998-03-01

    Doses currently received in Belarus through various pathways related to the contamination of forests are evaluated through calculations. A major pathway is, as expected, generally found to be the external radiation from a contaminated forest floor. Also other pathways may in some cases be highly significant. Generally, it is found that the dose contributions to people spending time in the contaminated forest or consuming forest products are highest, whereas for instance doses received from domestic use of fire-wood are found to be negligible. Recommendations for storage of waste from combustion plants fired with radioactive forest material are also given, together with an estimate of the specific activity of the waste to be disposed of.

  6. Risk assessment for chemical pickling of metals contaminated by radioactive materials.

    PubMed

    Donzella, A; Formisano, P; Giroletti, E; Zenoni, A

    2007-01-01

    In recent years, many cases of contamination of metal scraps by unwanted radioactive materials have occurred. Moreover, international organisations are evaluating the possibility to re-use or to recycle metals coming from nuclear power plants. The metal recycling industry has started to worry about radiation exposure of workers that could be in contact with contaminated metals during each manufacturing phase. Risks are strongly dependent on the radiation source features. The aim of this study is to perform risk assessment for workers involved in chemical pickling of steel coils. Monte Carlo simulations have been performed, using the MCNP package and considering coils contaminated with (60)Co, (137)Cs, (241)Am and (226)Ra. Under the most conservative conditions (coil contaminated with 1.0 kBq g(-1) of (60)Co), the dose assessment results lower than the European dose limit for the population (1 mSv y(-1)), considering a maximum number of 10 contaminated coils handled per year. The only exception concerns the case of (241)Am, for which internal contamination could be non- negligible and should be verified in the specific cases. In every case, radiation exposure risk for people standing at 50 m from the coil is widely <1 mSv y(-1). PMID:16849378

  7. 8. Atmospheric, water, and soil contamination after Chernobyl.

    PubMed

    Yablokov, Alexey V; Nesterenko, Vassily B; Nesterenko, Alexey V

    2009-11-01

    Air particulate activity over all of the Northern Hemisphere reached its highest levels since the termination of nuclear weapons testing--sometimes up to 1 million times higher than before the Chernobyl contamination. There were essential changes in the ionic, aerosol, and gas structure of the surface air in the heavily contaminated territories, as measured by electroconductivity and air radiolysis. Many years after the catastrophe aerosols from forest fires have dispersed hundreds of kilometers away. The Chernobyl radionuclides concentrate in sediments, water, plants, and animals, sometimes 100,000 times more than the local background level. The consequences of such a shock on aquatic ecosystems is largely unclear. Secondary contamination of freshwater ecosystems occurs as a result of Cs-137 and Sr-90 washout by the high waters of spring. The speed of vertical migration of different radionuclides in floodplains, lowland moors, peat bogs, etc., is about 2-4 cm/year. As a result of this vertical migration of radionuclides in soil, plants with deep root systems absorb them and carry the ones that are buried to the surface again. This transfer is one of the important mechanisms, observed in recent years, that leads to increased doses of internal irradiation among people in the contaminated territories. PMID:20002050

  8. Phosphate sources and their suitability for remediation of contaminated soils.

    PubMed

    Knox, A S; Kaplan, D I; Paller, M H

    2006-03-15

    Phosphate minerals and specifically apatite show promise for environmental cleanup because they can form stable compounds with a wide range of cationic contaminants. However, phosphate minerals naturally accumulate some heavy metals that may cause additional contamination of the environment if used improperly. Nine commercially available phosphate materials were evaluated for remediation of contaminated soil based on solubility, concentration of metal/metalloid impurities, and leachability of impurity metal/metalloids. The phosphate materials consisted of three groups: processed (i.e., fertilizers), mined (rock phosphates from different formations), and biogenic (ground fish bone). Processed and mined rock phosphates contained relatively high total concentrations of As, Co, Cr, and Cu but did not exceed the RCRA toxicity characteristic leaching procedure (TCLP) limits. Biogenic apatite contained much lower metal concentrations than processed and mined rock phosphate and was appreciably more soluble. By combining biogenic and mined phosphate it is possible to obtain a wide range of phosphate release rates, permitting rapid immobilization of contaminants while providing a slow release of phosphate for continued long-term treatment. PMID:16150478

  9. Phytotoxicity of trace metals in spiked and field-contaminated soils: Linking soil-extractable metals with toxicity.

    PubMed

    Hamels, Fanny; Malevé, Jasmina; Sonnet, Philippe; Kleja, Dan Berggren; Smolders, Erik

    2014-11-01

    Soil tests have been widely developed to predict trace metal uptake by plants. The prediction of metal toxicity, however, has rarely been tested. The present study was set up to compare 8 established soil tests for diagnosing phytotoxicity in contaminated soils. Nine soils contaminated with Zn or Cu by metal mining, smelting, or processing were collected. Uncontaminated reference soils with similar soil properties were sampled, and series of increasing contamination were created by mixing each with the corresponding soil. In addition, each reference soil was spiked with either ZnCl2 or CuCl2 at several concentrations. Total metal toxicity to barley seedling growth in the field-contaminated soils was up to 30 times lower than that in corresponding spiked soils. Total metal (aqua regia-soluble) toxicity thresholds of 50% effective concentrations (EC50) varied by factors up to 260 (Zn) or 6 (Cu) among soils. For Zn, variations in EC50 thresholds decreased as aqua regia > 0.43 M HNO3  > 0.05 M ethylenediamine tetraacetic acid (EDTA) > 1 M NH4 NO3  > cobaltihexamine > diffusive gradients in thin films (DGT) > 0.001 M CaCl2 , suggesting that the last extraction is the most robust phytotoxicity index for Zn. The EDTA extraction was the most robust for Cu-contaminated soils. The isotopically exchangeable fraction of the total soil metal in the field-contaminated soils markedly explained the lower toxicity compared with spiked soils. The isotope exchange method can be used to translate soil metal limits derived from soils spiked with metal salts to site-specific soil metal limits. PMID:25053440

  10. Stabilization/Solidification Remediation Method for Contaminated Soil: A Review

    NASA Astrophysics Data System (ADS)

    Tajudin, S. A. A.; Azmi, M. A. M.; Nabila, A. T. A.

    2016-07-01

    Stabilization/Solidification (S/S) is typically a process that involves a mixing of waste with binders to reduce the volume of contaminant leachability by means of physical and chemical characteristics to convert waste in the environment that goes to landfill or others possibly channels. Stabilization is attempts to reduce the solubility or chemical reactivity of the waste by changing the physical and chemical properties. While, solidification attempt to convert the waste into easily handled solids with low hazardous level. These two processes are often discussed together since they have a similar purpose of improvement than containment of potential pollutants in treated wastes. The primary objective of this review is to investigate the materials used as a binder in Stabilization/Solidification (S/S) method as well as the ability of these binders to remediate the contaminated soils especially by heavy metals.

  11. Defenses against keratinolytic bacteria in birds living in radioactively contaminated areas.

    PubMed

    Ruiz-Rodríguez, Magdalena; Møller, Anders Pape; Mousseau, Timothy A; Soler, Juan J

    2016-10-01

    Microorganisms have shaped the evolution of a variety of defense mechanisms against pathogenic infections. Radioactivity modifies bacterial communities and, therefore, bird hosts breeding in contaminated areas are expected to adapt to the new bacterial environment. We tested this hypothesis in populations of barn swallows (Hirundo rustica) from a gradient of background radiation levels at Chernobyl and uncontaminated controls from Denmark. Investment in defenses against keratinolytic bacteria was measured from feather structure (i.e., susceptibility to degradation) and uropygial secretions. We studied degradability of tail feathers from areas varying in contamination in laboratory experiments using incubation of feathers with a feather-degrading bacterium, Bacillus licheniformis, followed by measurement of the amount of keratin digested. The size of uropygial glands and secretion amounts were quantified, followed by antimicrobial tests against B. licheniformis and quantification of wear of feathers. Feathers of males, but not of females, from highly contaminated areas degraded at a lower rate than those from medium and low contamination areas. However, feathers of both sexes from the Danish populations showed little evidence of degradation. Individual barn swallows from the more contaminated areas of Ukraine produced the largest uropygial secretions with higher antimicrobial activity, although wear of feathers did not differ among males from different populations. In Denmark, swallows produced smaller quantities of uropygial secretion with lower antimicrobial activity, which was similar to swallow populations from uncontaminated areas in Ukraine. Therefore, barn swallows breeding in contaminated areas invested more in all defenses against keratinolytic bacteria than in uncontaminated areas of Ukraine and Denmark, although they had similar levels of feather wear. Strong natural selection exerted by radioactivity may have selected for individuals with higher defense

  12. Comparison of the accident process, radioactivity release and ground contamination between Chernobyl and Fukushima-1.

    PubMed

    Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

    2015-12-01

    In this report, we have reviewed the basic features of the accident processes and radioactivity releases that occurred in the Chernobyl accident (1986) and in the Fukushima-1 accident (2011). The Chernobyl accident was a power-surge accident that was caused by a failure of control of a fission chain reaction, which instantaneously destroyed the reactor and building, whereas the Fukushima-1 accident was a loss-of-coolant accident in which the reactor cores of three units were melted by decay heat after losing the electricity supply. Although the quantity of radioactive noble gases released from Fukushima-1 exceeded the amount released from Chernobyl, the size of land area severely contaminated by (137)Cesium ((137)Cs) was 10 times smaller around Fukush