Science.gov

Sample records for 05-19-02 contaminated soil

  1. (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.

  2. 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.

  3. Evaluating soil contamination

    USGS Publications Warehouse

    Beyer, W.N.

    1990-01-01

    This 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. There are several entries for a few of the most thoroughly studied contaminants, but for most of them the information available is meager. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Process for treating contaminated soil

    SciTech Connect

    Lebowitz, H.E.; Kulik, C.J.

    1995-10-24

    A process is provided for treating soil contaminated with oils, tars and light hydrocarbons. A slurry is formed with coal, water and the contaminated soil and agitated at elevated temperature, resulting in the transfer of the oil from the soil to the coal. The coal and soil mixture is then dewatered for disposal by burning or burial in a landfill. 2 figs.

  8. Evaluating potential groundwater contamination from contaminated soils

    SciTech Connect

    Pratt, J.R.; McCormick, P.V.; Pontasch, K.W.; Cairns, J.

    1987-01-01

    Contamination of soils at toxic and hazardous-waste sites can adversely affect groundwater and surface water. Water-soluble materials can move in soil by leaching and percolation and by runoff. The project evaluated the toxicity of leachable toxicants from seven soils, five of which were obtained from designated toxic or hazardous-waste sites. Acidified, dechlorinated tap water was used to extract toxic materials from surface soils. Extracts were used as complex mixtures in acute-toxicity tests using Daphnia and in chronic-effect tests using microcosms. Three classes of effects were observed. Some leachates (including control soils) showed no toxicity. Some soil leachates had moderate acute toxicity (50-80% diluted leachate) and no chronic toxicity. Very toxic soils showed both acute and chronic toxicity at <3% leachate. Toxicological evaluations of contaminants in waste-site soils can provide information not available from chemical analyses and may be useful in verifying the effectiveness of cleanup effort.

  9. Hydrocarbon contaminated soils and groundwater

    SciTech Connect

    Kostecki, P.T.

    1992-01-01

    This book contains the proceedings of hydrocarbon contaminated soils and groundwater. Topics covered include: Perspectives on hydrocarbon contamination; regulations; environmental fate and modeling; sampling and site assessment; remediation assessment and design; and remediation case studies.

  10. Natural attenuation of contaminated soils.

    PubMed

    Mulligan, Catherine N; Yong, Raymond N

    2004-06-01

    Natural attenuation is increasing in use as a low cost means of remediating contaminated soil and groundwater. Modelling of contaminant migration plays a key role in evaluating natural attenuation as a remediation option and in ensuring that there will be no adverse impact on humans and the environment. During natural attenuation, the contamination must be characterized thoroughly and monitored through the process. In this paper, attenuation mechanisms for both organic and inorganic contaminants, use of models and protocols, role of monitoring and field case studies will be reviewed.

  11. Treatment of radionuclide contaminated soils

    SciTech Connect

    Pettis, S.A.; Kallas, A.J.; Kochen, R.L.; McGlochlin, S.C.

    1988-06-01

    Rockwell, International, Rocky Flats Plants, is committed to remediating within the scope of RCRA/CERCLA, Solid Waste Managements Units (SWMUs) at Rocky Flats found to be contaminated with hazardous substances. SWMUs fund to have radionuclide (uranium, plutonium, and/or americium) concentrations in the soils and/or groundwater that exceed background levels or regulatory limits will also be included in this remediation effort. This paper briefly summarizes past and present efforts by Rockwell International, Rocky Flats Plant, to identify treatment technologies appropriate for remediating actinide contaminated soils. Many of the promising soil treatments evaluated in Rocky Flats' laboratories during the late 1970's and early 1980's are currently being revisited. These technologies are generally directed toward substantially reducing the volume of contaminated soils, with the subsequent intention of disposing of a small remaining concentrated fraction of contaminated soil in a facility approved to receive radioactive wastes. Treatment processes currently will be treated to remove actinides, and recycled back to the process. Past investigations have included evaluations of dry screening, wet screening, scrubbing, ultrasonics, chemical oxidation, calcination, desliming, flotation, and heavy-liquid density separation. 8 refs., 2 figs.

  12. 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...

  13. 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.

  14. Review of soil contamination guidance

    SciTech Connect

    Mueller, M.A.; Kennedy, W.E. Jr.; Soldat, J.K.

    1981-08-01

    A review of existing and proposed radioactive soil contamination standards and guidance was conducted for United Nuclear Corporation (UNC), Office of Surplus Facilities Management. Information was obtained from both government agencies and other sources during a literature survey. The more applicable standards were reviewed, evaluated, and summarized. Information pertaining to soil contamination for both facility operation and facility decommissioning was obtained from a variety of sources. These sources included: the Code of Federal Regulations, regulatory guides, the Federal Register, topical reports written by various government agencies, topical reports written by national laboratories, and publications from the American National Standards Institute (ANSI). It was difficult to directly compare the standards and guidance obtained from these sources since each was intended for a specific situation and different units or bases were used. However, most of the information reviewed was consistent with the philosophy of maintaining exposures at levels as low as reasonably achievable (ALARA).

  15. Cleaning up soils contaminated with petroleum hydrocarbons

    SciTech Connect

    Arniella, E.F. ); Holley, R.E. )

    1991-08-01

    This article describes one new technology used to clean up soils contaminated with petroleum hydrocarbons from underground storage tanks. Topics covered include cleanup criteria, soil remediation technologies, air stripping-soil venting system and process design and performance. This contaminated site was located in the Atlanta, Georgia metropolitan area.

  16. 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.

  17. 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...

  18. Hydrogen peroxide treatment of TCE contaminated soil

    SciTech Connect

    Hurst, D.H.; Robinson, K.G.; Siegrist, R.L.

    1993-12-31

    Solvent contaminated soils are ubiquitous in the industrial world and represent a significant environmental hazard due to their persistence and potentially negative impacts on human health and the environment. Environmental regulations favor treatment of soils with options which reduce the volume and toxicity of contaminants in place. One such treatment option is the in-situ application of hydrogen peroxide to soils contaminated with chlorinated solvents such as trichloroethylene (TCE). This study investigated hydrogen peroxide mass loading rates on removal of TCE from soils of varying organic matter content. Batch experiments conducted on contaminated loam samples using GC headspace analysis showed up to 80% TCE removal upon peroxide treatment. Column experiments conducted on sandy loam soils with high organic matter content showed only 25% TCE removal, even at hydrogen peroxide additions of 25 g peroxide per kg soil.

  19. 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.

  20. 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.

  1. 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.

  2. Assessing inhalation exposure from airborne soil contaminants

    SciTech Connect

    Shinn, J.H.

    1998-04-01

    A method of estimation of inhalation exposure to airborne soil contaminants is presented. this method is derived from studies of airborne soil particles with radioactive tags. The concentration of contaminants in air (g/m{sup 3}) can be derived from the product of M, the suspended respirable dust mass concentration (g/m{sup 3}), S, the concentration of contaminant in the soil (g/g), and E{sub f}, an enhancement factor. Typical measurement methods and values of M, and E{sub f} are given along with highlights of experiences with this method.

  3. 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.

  4. Surfactant screening of diesel-contaminated soil

    SciTech Connect

    Peters, R.W.; Montemagno, C.D.; Shem, L. ); Lewis, B.A. . Dept. of Civil Engineering)

    1990-01-01

    At one installation, approximately 60,000 gal of No. 2 diesel fuel leaked into the subsurface environment, with contamination at depths of 6 to 34 m below the surface. Argonne National Laboratory was contracted to perform treatability studies for site remediation. The treatability studies focused on four separate phases: (1) leachability studies on the various contaminated soil borings, (2) air stripping studies, (3) bioremediation studies, and (4) surfactant screening/surfactant flooding studies. This paper summarizes the fourth phase of the research program in which twenty-one surfactants were screened for possible use to mobilize the organics from the contaminated soil prior to bioremediation. Anionic surfactants resulted in the greatest degree of diesel mobilization. The most promising surfactants will be employed on actual contaminated soil samples obtained from the site. 18 refs., 16 figs., 1 tab.

  5. 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...

  6. 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.

  7. 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

  8. 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

  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. 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.

  12. 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.

  13. 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.

  14. Bioremediation of hydrocarbon-contaminated polar soils.

    PubMed

    Aislabie, Jackie; Saul, David J; Foght, Julia M

    2006-06-01

    Bioremediation is increasingly viewed as an appropriate remediation technology for hydrocarbon-contaminated polar soils. As for all soils, the successful application of bioremediation depends on appropriate biodegradative microbes and environmental conditions in situ. Laboratory studies have confirmed that hydrocarbon-degrading bacteria typically assigned to the genera Rhodococcus, Sphingomonas or Pseudomonas are present in contaminated polar soils. However, as indicated by the persistence of spilled hydrocarbons, environmental conditions in situ are suboptimal for biodegradation in polar soils. Therefore, it is likely that ex situ bioremediation will be the method of choice for ameliorating and controlling the factors limiting microbial activity, i.e. low and fluctuating soil temperatures, low levels of nutrients, and possible alkalinity and low moisture. Care must be taken when adding nutrients to the coarse-textured, low-moisture soils prevalent in continental Antarctica and the high Arctic because excess levels can inhibit hydrocarbon biodegradation by decreasing soil water potentials. Bioremediation experiments conducted on site in the Arctic indicate that land farming and biopiles may be useful approaches for bioremediation of polar soils.

  15. 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.

  16. Mutagens in contaminated soil: a review.

    PubMed

    White, Paul A; Claxton, Larry D

    2004-11-01

    The intentional and accidental discharges of toxic pollutants into the lithosphere results in soil contamination. In some cases (e.g., wood preserving wastes, coal-tar, airborne combustion by-products), the contaminated soil constitutes a genotoxic hazard. This work is a comprehensive review of published information on soil mutagenicity. In total, 1312 assessments of genotoxic activity from 118 works were examined. The majority of the assessments (37.6%) employed the Salmonella mutagenicity test with strains TA98 and/or TA100. An additional 37.6% of the assessments employed a variety of plant species (e.g., Tradescantia clone 4430, Vicia faba, Zea mays, Allium cepa) to assess mutagenic activity. The compiled data on Salmonella mutagenicity indicates significant differences (p<0.0001) in mean potency (revertents per gram dry weight) between industrial, urban, and rural/agricultural sites. Additional analyses showed significant empirical relationships between S9-activated TA98 mutagenicity and soil polycyclic aromatic hydrocarbon (PAH) concentration (r2=0.19 to 0.25, p<0.0001), and between direct-acting TA98 mutagenicity and soil dinitropyrene (DNP) concentration (r2=0.87, p<0.0001). The plant assay data revealed excellent response ranges and significant differences between heavily contaminated, industrial, rural/agricultural, and reference sites, for the anaphase aberration in Allium cepa (direct soil contact) and the waxy locus mutation assay in Zea mays (direct soil contact). The Tradescantia assays appeared to be less responsive, particularly for exposures to aqueous soil leachates. Additional data analyses showed empirical relationships between anaphase aberrations in Allium, or mutations in Arabidopsis, and the 137Cs contamination of soils. Induction of micronuclei in Tradescantia is significantly related to the soil concentration of several metals (e.g., Sb, Cu, Cr, As, Pb, Cd, Ni, Zn). Review of published remediation exercises showed effective removal of

  17. 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...

  18. 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...

  19. 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...

  20. 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.

  1. 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

  2. Landfarming in a PAH-contaminated soil.

    PubMed

    Picado, A; Nogueira, A; Baeta-Hall, L; Mendonça, E; de Fátima Rodrigues, M; do Céu Sàágua, M; Martins, A; Anselmo, A M

    2001-01-01

    The present work describes a coke oven soil treatability study by land-farming, conducted on-site in a field scale facility covering 100 m2. The soil contamination was mainly due to high concentrations of polynuclear aromatic hydrocarbons (PAHs) up to 1,140 mg/Kg dry weight (sigma EPA). Along the treatment process the soil was characterised at the chemical, microbiological and ecotoxicological levels. After 3 months a reduction of 63% in total PAHs concentration was observed, being detected a more pronounced reduction for PAHs with 2, 3 and 4 rings (79%). Concomitantly, a change in the composition of the microbial population was observed with a significant increase in the PAHs degrading and total heterotrophic colonies. Concerning the ecotoxicity and genotoxicity data no effect was detected in the treated soil samples eluates.

  3. Soil Properties Controlling Zn Speciation and Fractionation in Contaminated Soils

    SciTech Connect

    Jacquat, O.; Voegelin, A; Kretzschmar, R

    2009-01-01

    We determined the speciation of Zn in 49 field soils differing widely in pH (4.1-7.7) and total Zn content (251-30,090 mg/kg) by using extended X-ray absorption fine structure (EXAFS) spectroscopy. All soils had been contaminated since several decades by inputs of aqueous Zn with runoff-water from galvanized power line towers. Pedogenic Zn species identified by EXAFS spectroscopy included Zn in hydroxy-interlayered minerals (Zn-HIM), Zn-rich phyllosilicates, Zn-layered double hydroxide (Zn-LDH), hydrozincite, and octahedrally and tetrahedrally coordinated sorbed or complexed Zn. Zn-HIM was only observed in (mostly acidic) soils containing less than 2000 mg/kg of Zn, reflecting the high affinity but limited sorption capacity of HIM. Zn-bearing precipitates, such as Zn-LDH and Zn-rich trioctahedral phyllosilicates, became more dominant with increasing pH and increasing total Zn content relative to available adsorption sites. Zn-LDH was the most abundant Zn-precipitate and was detected in soils with pH > 5.2. Zn-rich phyllosilicates were detected even at lower soil pH, but were generally less abundant than Zn-LDH. Hydrozincite was only identified in two calcareous soils with extremely high Zn contents. In addition to Zn-LDH, large amounts of Zn in highly contaminated soils were mainly accumulated as sorbed/complexed Zn in tetrahedral coordination. Soils grouped according to their Zn speciation inferred from EXAFS spectroscopy mainly differed with respect to soil pH and total Zn content. Clear differences were observed with respect to Zn fractionation by sequential extraction: From Zn-HIM containing soils, most of the total Zn was recovered in the exchangeable and the most recalcitrant fractions. In contrast, from soils containing the highest percentage of Zn-precipitates, Zn was mainly extracted in intermediate extraction steps. The results of this study demonstrate that soil pH and Zn contamination level relative to available adsorption sites are the most important

  4. Microwave remediation of soil contaminated with hexachlorobenzene.

    PubMed

    Yuan, Songhu; Tian, Meng; Lu, Xiaohua

    2006-09-21

    This study describes the remediation of hexachlorobenzene (HCB) contaminated soils by microwave (MW) radiation in a sealed vial. When powdered MnO2 was used as MW absorber, a complete removal of HCB was obtained with 10 min MW by the addition of H2SO4 (50%). But no significant decomposition was observed by the addition of NaOH (10 mol/L) or H2O in the same conditions. In contrast, when powdered Fe was used instead of MnO2, the difference of HCB removals between H2SO4 and NaOH were not obvious. It is noteworthy that more than 95% removal was achieved in any case when the sole aqueous solution of H2SO4, NaOH, H2O or Na2SO4 was added without MnO2 or Fe. As a result, it is possible that water itself contained in the damp soil may act as MW absorber and remediate the contaminated soil without addition of any other MW absorbers. Gas chromatograph/mass spectrum (GC/MS) analysis detected no intermediates in all the processes. The decomposition mechanism of HCB by MW radiation was suggested as the binding of HCB and soil. Whatever fragments formed from HCB by heat were tightly bound to the soil, making it impossible to extract them out. In the end, treatment of practical HCB contaminated soil by MW reduced HCB from 55.8 mg/kg to 0.91 mg/kg.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. The organic contamination level based on the total soil mass is not a proper index of the soil contamination intensity

    USGS Publications Warehouse

    Hung, H.-W.; Daniel, Sheng G.; Lin, T.-F.; Su, Y.; Chiou, C.T.

    2009-01-01

    Concentrations of organic contaminants in common productive soils based on the total soil mass give a misleading account of actual contamination effects. This is attributed to the fact that productive soils are essentially water-saturated, with the result that the soil uptake of organic compounds occurs principally by partition into the soil organic matter (SOM). This report illustrates that the soil contamination intensity of a compound is governed by the concentration in the SOM (Com) rather than by the concentration in whole soil (Cs). Supporting data consist of the measured levels and toxicities of many pesticides in soils of widely differing SOM contents and the related levels in in-situ crops that defy explanation by the Cs values. This SOM-based index is timely needed for evaluating the contamination effects of food crops grown in different soils and for establishing a dependable priority ranking for intended remediation of numerous contamination sites.

  12. 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.

  13. 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.

  14. In situ venting of jet fuel-contaminated soil

    SciTech Connect

    Elliott, M.G.; DePaoli, D.W.

    1989-01-01

    The Air Force Engineering and Services center is performing a field demonstration of in situ soil venting at a 27,000-gallon jet fuel spill site at Hill AFB UT. In situ soil venting is a soil cleanup technique which uses vacuum blowers to pull large volumes of air through contaminated soil. The air flow sweeps out the soil gas, disrupting the equilibrium existing between the contaminants on the soil and in the vapor. This causes volatilization of the contaminants and subsequent removal in the air stream. In situ soil venting has been used for removing volatile contaminants such as gasoline and trichloroethylene, but a full-scale demonstration for removing jet fuel from soil has not been reported. This paper describes our initial site characterization, the one-vent pilot test, and the design and preliminary results of our full-scale in situ soil venting system. 5 refs., 7 figs.

  15. 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

  16. 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....

  17. 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.

  18. 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.

  19. 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

  20. Radiolytic treatment of dioxin contaminated soils

    NASA Astrophysics Data System (ADS)

    Gray, Kimberly A.; Hilarides, Roger J.

    1995-09-01

    Recent work in our laboratory has demonstrated that γ-radiolysis is a feasible method by which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can be converted to products of negligible toxicity. In the presence of 25% water, 2.5% non-ionic surfactant and at a dose of 800 kGy greater than 98% destruction was achieved in a standard soil artificially contaminated with 100 ppb TCDD. By-product analysis has illustrated that the destruction occurs via step-wise reductive dechlorination producing a suite of lesser chlorinated dioxins. These results in combination with scavenger studies, target theory calculations and yields indicate that direct radiation effects account for the major route of destruction. Radiolysis has also been conducted on a real soil contaminated with TCDD and other chlorinated aromatic compounds verifying the results of model studies. Based on the data of these experiments some designs of batch gamma systems are considered and a discussion of estimated capital and operating costs associated with γ-radiolysis is presented. Given the high costs of the alternatives (i.e. incineration), radiolysis appears to be not only technically feasible, but it may also be economically competitive.

  1. 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...

  2. 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.

  3. Full-scale anaerobic bioremediation of trinitrotoluene (TNT) contaminated soil

    SciTech Connect

    Funk, S.B.; Crawford, D.L.; Crawford, R.L.

    1995-12-31

    An anaerobic bioremediation process for the degradation of nitroaromatic compounds in soil was demonstrated. This ex situ process was demonstrated full-scale at a 2,4,6-trinitrotoluene (TNT)-contaminated site near Weldon Spring, MO. A bioreactor was loaded with approx 23 m{sup 3} of TNT-contaminated soil in the form of a 50:50 soil: water slurry. This slurry was augmented with a starchy carbon source (1-2% w/v) and buffered with phosphate to near-neutral pH. Indigenous soil bacteria utilized the oxygen, making the slurry anaerobic within 1-2 d. Anaerobes then degraded the TNT (3000 mg/kg) in approx 11 wk. A relatively long treatment time for the bioremediation of the TNT-contaminated soil was necessary, possibly because of the cool ambient temperatures, high clay content of the soil, high level of contamination, and high level of recalcitrance of TNT in soils.

  4. Layer of organic pine forest soil on top of chlorophenol-contaminated mineral soil enhances contaminant degradation.

    PubMed

    Sinkkonen, Aki; Kauppi, Sari; Simpanen, Suvi; Rantalainen, Anna-Lea; Strömmer, Rauni; Romantschuk, Martin

    2013-03-01

    Chlorophenols, like many other synthetic compounds, are persistent problem in industrial areas. These compounds are easily degraded in certain natural environments where the top soil is organic. Some studies suggest that mineral soil contaminated with organic compounds is rapidly remediated if it is mixed with organic soil. We hypothesized that organic soil with a high degradation capacity even on top of the contaminated mineral soil enhances degradation of recalcitrant chlorophenols in the mineral soil below. We first compared chlorophenol degradation in different soils by spiking pristine and pentachlorophenol-contaminated soils with 2,4,6-trichlorophenol in 10-L buckets. In other experiments, we covered contaminated mineral soil with organic pine forest soil. We also monitored in situ degradation on an old sawmill site where mineral soil was either left intact or covered with organic pine forest soil. 2,4,6-Trichlorophenol was rapidly degraded in organic pine forest soil, but the degradation was slower in other soils. If a thin layer of the pine forest humus was added on top of mineral sawmill soil, the original chlorophenol concentrations (high, ca. 70 μg g(-1), or moderate, ca. 20 μg g(-1)) in sawmill soil decreased by >40 % in 24 days. No degradation was noticed if the mineral soil was kept bare or if the covering humus soil layer was sterilized beforehand. Our results suggest that covering mineral soil with an organic soil layer is an efficient way to remediate recalcitrant chlorophenol contamination in mineral soils. The results of the field experiment are promising.

  5. 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...

  6. Phytoremediation of organic contaminants in soil and groundwater.

    PubMed

    Reichenauer, Thomas G; Germida, James J

    2008-01-01

    Phytoremediation is an emerging technology for the clean-up of sites contaminated with hazardous chemicals. The term phytoremediation refers to a number of technologies that use photoautotrophic vascular plants for the remediation of sites contaminated with inorganic and organic contaminants. Phytoremediation of organic contaminants can be organized by considering 1) the green liver concept, which elucidates the metabolism of contaminants in planta versus that of contaminants ex planta (e.g. rhizosphere), 2) processes that lead to complete degradation (mineralization) of contaminants as opposed to those that only lead to partial degradation or transformation, and 3) active plant uptake versus passive processes (e.g. sorption). Understanding of these processes needs an interdisciplinary approach involving chemists, biologists, soil scientists, and environmentalists. This Review presents the basic concepts of phytoremediation of organic contaminants in soil and groundwater using selected contaminants as examples.

  7. Accumulation of heavy metals in oil-contaminated peat soils

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.; Savichev, A. T.; Trofimov, S. Ya.; Shishkonakova, E. A.

    2012-10-01

    X-ray fluorescence and X-ray radiometry represent easy and simple methods to determine concentrations of heavy metals in the ash of peat soils contaminated with oil and can be applied for soil monitoring purposes. Oil spills on peat bogs produce two contamination zones differing in the composition of heavy metals. In the zone of primary contamination, the peat surface is covered by a bitumen crust with V, Ni, Sr, Ba, Ce, and La accumulating there. This zone adjoins the zone of secondary peat contamination, where heavy alkaline-earth metals (Sr, Ba) and lanthanides (Ce and La) are accumulated to a lesser extent. Biological preparations recommended for remediation of oil-contaminated peat soils should be tolerant to high concentrations of heavy metals, particularly, V, Ni, and Ba that are present in the oil contaminated soils in relatively high amounts.

  8. Pressure-assisted chelation extraction of lead from contaminated soil.

    PubMed

    Hong, P K Andy; Cai, Xiaoxiao; Cha, Zhixiong

    2008-05-01

    Soil contamination by metallic elements including lead occurs frequently. Contaminant metals in soil pose a serious risk to public health and groundwater supplies. Extraction using chelants is seen as a remediation option; however, it is often hampered by access to the contaminants that are shielded by the soil matrix. We have developed a novel extraction technique that utilizes a mildly elevated pressure in consecutive cycles of compression and decompression along with a chelating agent for the soil slurry. Complete extraction of 3300 mg/kg of Pb from soil was achieved by 100 mM of EDTA (ethylenediaminetetraacetic acid) in 10 min using 20 pressure cycles at 150 psi (10 atm). Extraction was studied according to pressure, number of pressure cycles, chelant concentration, solid content, pH, agitation, and use of consecutive washings. Heightened extraction is attributed to fracturing of the soil particles that leads to enhanced contaminant exposure to the chelating agent.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. [Vapor extraction technology in oil contaminated soil remediation].

    PubMed

    Li, Jinhui; Nie, Yongfeng; Ma, Haibin; Xia, Xin; Liang, Fuyan; Zhen, Xiaoyue

    2002-01-30

    In order to study the Vapor Extraction Technology that can be applied to China, on the basis of mechanism analysis of Vapor Extraction Technology for oil-contaminated soil, a simplified and practical contaminant removal model to simulate the soil remediation time was presented. With the typical unsaturated soils in North of China, the effects of the vapor flow rate, soil water content and quality on the remediation process were studied. The results showed that the best value of flow velocity was existed, and water content had different influence on different kinds of soil, for silty soil, the efficiency of remediation enhanced with water content increase, but there was a reverse result for clayey soil. Through one-dimension soil column experiments, the results showed that these factors had different effects on remediation time. The research using the soil column apparatus show that the predicted results were validated and the applied conditions of this model were qualified.

  14. 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.

  15. 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.

  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. In Situ Remediation and Ecosystem Restoration on Toxic Mine and Smelter Contaminated Soils Using Soil Amendments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At many locations, dispersal of mine wastes or smelter emissions caused extensive contamination of soils with Zn, Cd, Pb, Ni, or Cu and associated elements. When contaminated soils are acidic (from pyrite in ores, or SO2 emissions, or native acidic soils), highly phytoavailable Zn or Ni caused seve...

  18. Pleasure Boatyard Soils are Often Highly Contaminated

    NASA Astrophysics Data System (ADS)

    Eklund, Britta; Eklund, David

    2014-05-01

    The contamination in pleasure boatyards has been investigated. Measured concentrations of copper, zinc, lead, mercury, cadmium, tributyltin (TBT), the 16 most common polycyclic aromatic hydrocarbons (∑16 PAHs), and the seven most common polychlorinated biphenyls (∑7 PCBs) from investigations at 34 boatyards along the Swedish coast have been compiled. The maximum concentrations were 7,700 for Cu, 10,200, for Zn, 40,100 for Pb, 188 for Hg, 18 for Cd, 107 for TBT, 630 for carcinogenic PAHs, 1,480 for ∑16 PAHs, and 3.8 mg/kg DW for ∑7 PCB; all 10-2,000 higher than the Swedish environmental qualitative guidelines. In addition, the mean of the median values found at the 34 places shows that the lower guidance value for sensitive use of land was exceeded for the ∑7 PCBs, carcinogenic PAHs, TBT, Pb, Hg, and Cu by a factor of 380, 6.8, 3.6, 2.9, 2.2 and 1.7, respectively. The even higher guideline value for industrial use was exceeded for the ∑7 PCBs and TBT by a factor of 15 and 1.8, respectively. TBT, PAHs, Pb, Cd, and Hg are prioritized substances in the European Water Framework Directive and should be phased out as quickly as possible. Because of the risk of leakage from boatyards, precautions should be taken. The high concentrations measured are considered to be dangerous for the environment and human health and highlight the urgent need for developing and enforcing pleasure boat maintenance guidelines to minimize further soil and nearby water contamination.

  19. 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.

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

    PubMed

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

    2016-01-01

    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 180th 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 180th 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 180th 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.

  1. 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.

  2. 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.

  3. Bioventing remediation and ecotoxicity evaluation of phenanthrene-contaminated soil.

    PubMed

    García Frutos, F Javier; Escolano, Olga; García, Susana; Babín, Mar; Fernández, M Dolores

    2010-11-15

    The objectives of soil remediation processes are usually based on threshold levels of soil contaminants. However, during remediation processes, changes in bioavailability and metabolite production can occur, making it necessary to incorporate an ecotoxicity assessment to estimate the risk to ecological receptors. The evolution of contaminants and soil ecotoxicity of artificially phenanthrene-contaminated soil (1000 mg/kg soil) during soil treatment through bioventing was studied in this work. Bioventing was performed in glass columns containing 5.5 kg of phenanthrene-contaminated soil and uncontaminated natural soil over a period of 7 months. Optimum conditions of mineralisation (humidity=60% WHC; C/N/P=100:20:1) were determined in a previous work. The evolution of oxygen consumption, carbon dioxide production, phenanthrene concentration and soil toxicity were studied on sacrificed columns at periods of 0, 3 and 7 months. Toxicity to soil and aquatic organisms was determined using a multispecies system in the soil columns (MS-3). In the optimal bioventing treatability test, we obtained a reduction rate in phenanthrene concentration higher that 93% after 7 months of treatment. The residual toxicity obtained at the end of the treatment was not attributed to the low phenanthrene concentration, but to the ammonia used to restore the optimal C/N ratio.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. Laboratory and greenhouse assessment of phytoremediation of petroleum contaminated soils

    SciTech Connect

    Banks, M.K.; Schwab, A.P.; Wang, X.

    1996-12-31

    Phytoremediation of soils contaminated with petroleum and associated priority pollutants was evaluated in greenhouse and laboratory experiments. Mineralization of several PAHs was measured in rhizosphere soil, non-rhizosphere soil, and sterile soil amended with simulated root exudates. The least amount of mineralization was observed in sterile soil, but there were no differences among all other soils. Mineralization of 14 C-benzo[a]pyrene was determined in chambers to determine the effects of tall fescue on dissipation of this compound. After 180 days, the soils with fescue had more than twice the mineralization than soils without plants. In the soils with plants, evolution of 14CO2 from the soil was five times greater than from the plant biomass. These experiments demonstrate that the presence of plants is a necessary part of the phytoremediation process. There appears to be no residual rhizosphere effect, and the simple exudation of organic compounds does not mimic fully the presence of roots.

  10. 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.

  11. Earthworm metabolomic responses after exposure to aged PCB contaminated soils.

    PubMed

    Whitfield Åslund, Melissa; Simpson, Myrna J; Simpson, André J; Zeeb, Barbara A; Rutter, Allison

    2012-10-01

    (1)H NMR metabolomics was used to measure earthworm sub-lethal responses to polychlorinated biphenyls (PCBs) in historically contaminated (>30 years) soils (91-280 mg/kg Aroclor 1254/1260) after two and 14 days of exposure. Although our previous research detected a distinct earthworm metabolic response to PCBs in freshly spiked soil at lower concentrations (0.5-25 mg/kg Aroclor 1254), the results of this study suggest only weak or non-significant relationships between earthworm metabolic profiles and soil PCB concentrations. This concurs with the expectation that decades of contaminant aging have likely decreased PCB bioavailability and toxicity in the field. Instead of being influenced by soil contaminant concentration, earthworm metabolic profiles were more closely correlated to soil properties such as total soil carbon and soil inorganic carbon. Overall, these results suggested that (1)H NMR metabolomics may be capable of detecting both site specific responses and decreased contaminant bioavailability to earthworms after only two days of exposure, whereas traditional toxicity tests require much more time (e.g. 14 days for acute toxicity and >50 days for reproduction tests). Therefore, there is significant opportunity to develop earthworm metabolomics as a sensitive tool for rapid assessment of the toxicity associated with contaminated field soils.

  12. 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.

  13. 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

  14. 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).

  15. 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.

  16. Ecological effects of soil contamination at Aberdeen Proving Ground, Maryland

    SciTech Connect

    Kuperman, R.G.; Dunn, C.P. )

    1994-06-01

    Assessment of the ecological condition of contaminated soil was conducted in portions of the U.S. Army's Aberdeen Proving Ground, Maryland as part of an ecological risk assessment. This area is covered by open fields, woods and nontidal marshes. Chemicals disposed of in open burning pits included methylphosphonothioic acid, dichlorodiethyl sulfide, and titanium tetrachloride and sulfur trioxide/chlorosulfonic acid. Previous soil analysis showed extensive surface soil contamination with metals, nitrate, PCBs and pesticides. This assessment included characterizing soil biota, biologically-mediated processes in soil and aboveground biomass. Field surveys of the soil invertebrate communities showed significant reductions in the 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 [open quotes]background[close quotes] area. Laboratory toxicity 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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...

  3. 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.

  4. 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.

  5. Does Diffusion Sequester Heavy Metals in Old Contamination Soils?

    NASA Astrophysics Data System (ADS)

    Ma, J.; Jennings, A. A.

    2002-12-01

    Old soil contamination refers to soil contamination that has aged over a long period of time. For example, at some brownfields, the soil heavy metal contamination can be one hundred or more years old. When contamination is young, the heavy metals are bound relatively weakly to the soil. However, the speciation and/or mechanisms of association evolve with aging into much more stable forms. It also appears that the metals migrate deeper into the bulk soil matrix where they are less available to participate in surface-related phenomena. Previous research showed elevated heavy metal extraction result after the soil was pulverized, with all other experiment conditions remaining unchanged. This indicates the presence of sequestered heavy metal contamination within the large soil particles (aggregate). The mechanisms of sequestering are uncertain, but diffusion appears to be a major factor. There are two possible pathways of diffusion that can account for heavy metal sequestering: solid-state diffusion through the bulk aggregate or liquid-phase diffusion through micro-pores within the aggregate structure. The second diffusion mechanism can be coupled with sorption (or other surface-related phenomena) on the pore walls. The remediation of sequestered heavy metals is also impacted by diffusion. Grinding a soil significantly reduces its average particle size. This exposes more of its internal bulk volume to extraction and results in much shorter diffusion pathway for the sequestered heavy metals to be released. Evidence has illustrated that this both improves remediation efficiency and provides a method by which the degree of sequestering can be quantified. This paper will present the results of ongoing research that is developing methods to identify the mechanisms of, quantify the magnitude of and determine the relative importance of (i.e. risk analysis) heavy metals sequestered in old contamination soils.

  6. Evaluation of the Parameters of Radioactive Contamination of Soils

    SciTech Connect

    Panasyuk M.I.; Skorbun A.D.; Klyuchnikov O.O.

    2002-02-26

    After Chornobyl NPP (ChNPP) accident the territory near destroyed Unit 4 (that now with the special confinement has the name the ''Shelter'' object) is contaminated of fuel fallouts. During liquidation of the accident consequences this territory was covered with pure earth, concrete, etc. As a result a contaminated anthropogenic layer of the soil on the depth up to 10 m was formed. Now the problem of contamination estimation and the soils management arose. For this tasks a gamma logging method was modified conformably to ChNPP conditions. The methods for necessary coefficients receiving and log treatment have been suggested.

  7. 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.

  8. 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...

  9. Selection of plants for phytoremediation of soils contaminated with radionuclides

    SciTech Connect

    Entry J.A.; Vance, N.C.; Watrud, L.S.

    1996-12-31

    Remediation of soil contaminated with radionuclides typically requires that soil be removed from the site and treated with various dispersing and chelating chemicals. Numerous studies have shown that radionuclides are generally not leached from the top 0.4 meters of soil, where plant roots actively accumulate elements. Restoration of large areas of land contaminated with low levels of radionuclides may be feasible using phytoremediation. Criteria for the selection of plants for phytoremediation, molecular approaches to increase radio nuclide uptake, effects of cultural practices on uptake and assessment of environmental effects of phytoremediation will be discussed.

  10. Biotreatment of aqueous extract from chlorobenzene-contaminated soil

    SciTech Connect

    Guiot, S.R.; Frigon, J.C.; Albu-Cimpoia, R.; Deschamps, S.; Zhou, X.Q.; Hawari, J.; Sanschagrin, S.; Samson, R.

    1995-12-31

    Chlorobenzene-contaminated groundwater originating from soil steam flooding was considered for treatment in a biological reactor. The present study addresses optimal conditions for biotreatment of 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, and 1,2,4-trichlorobenzene at average initial concentrations (mg/L) of 25, 2.1, 3.9, and 0.4, respectively. Microcosm tests demonstrated that soil indigenous populations were able to mineralize all contaminants, with a 57 to 72% CO{sub 2} recovery. Assays were performed in a mechanically stirred bioreactor that was inoculated with contaminated soil and municipal activated sludge. Contaminants such as tri- and dichlorobenzene are easily degraded under aerobic conditions. Concentrations of all contaminants were less than 10 {micro}g/L in the released effluent after 30 to 45 days of reaction with soil at 5% (w/w) and dissolved O{sub 2} at 80% of saturation. Within the bioreactor operating range, the contaminant did not volatilize significantly. Biodegradation was preceded by a transient adsorption of the compounds. The specific rate of dichlorobenzene degradation was improved four-fold when the soil inoculum was supplemented with municipal activated sludge.

  11. 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

  12. 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.

  13. 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.

  14. Surfactant-enhanced remediation of organic contaminated soil and water.

    PubMed

    Paria, Santanu

    2008-04-21

    Surfactant based remediation technologies for organic contaminated soil and water (groundwater or surface water) is of increasing importance recently. Surfactants are used to dramatically expedite the process, which in turn, may reduce the treatment time of a site compared to use of water alone. In fact, among the various available remediation technologies for organic contaminated sites, surfactant based process is one of the most innovative technologies. To enhance the application of surfactant based technologies for remediation of organic contaminated sites, it is very important to have a better understanding of the mechanisms involved in this process. This paper will provide an overview of the recent developments in the area of surfactant enhanced soil and groundwater remediation processes, focusing on (i) surfactant adsorption on soil, (ii) micellar solubilization of organic hydrocarbons, (iii) supersolubilization, (iv) density modified displacement, (v) degradation of organic hydrocarbon in presence surfactants, (vi) partitioning of surfactants onto soil and liquid organic phase, (vii) partitioning of contaminants onto soil, and (viii) removal of organics from soil in presence of surfactants. Surfactant adsorption on soil and/or sediment is an important step in this process as it results in surfactant loss reduced the availability of the surfactants for solubilization. At the same time, adsorbed surfactants will retained in the soil matrix, and may create other environmental problem. The biosurfactants are become promising in this application due to their environmentally friendly nature, nontoxic, low adsorption on to soil, and good solubilization efficiency. Effects of different parameters like the effect of electrolyte, pH, soil mineral and organic content, soil composition etc. on surfactant adsorption are discussed here. Micellar solubilization is also an important step for removal of organic contaminants from the soil matrix, especially for low aqueous

  15. 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, ...

  16. 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.

  17. 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.

  18. Electrokinetic remediation of oil-contaminated soils.

    PubMed

    Korolev, Vladimir A; Romanyukha, Olga V; Abyzova, Anna M

    2008-07-01

    This investigation was undertaken to determine the factors influencing electrokinetic remediation of soils from petroleum pollutants. The remediation method was applied in two versions: (i) static and (ii) flowing, when a sample was washed with leaching solution. It was found that all the soils studied can be purified using this technique. It was also observed that the mineral and grain-size composition of soils, their properties, and other parameters affect the remediation efficiency. The static and flowing versions of the remediation method removed 25-75% and 90-95% of the petroleum pollutants, respectively from the soils under study.

  19. 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.

  20. 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.

  1. 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...

  2. Evaluation of soil amendments as a remediation alternative for cadmium contaminated soils under cacao plantations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Elevated plant-available cadmium (Cd) in soils results in contamination to cacao (Theobroma cacao L) beans. Effectiveness of vermicompost and zeolite in reducing available Cd in three cacao-growing soils was studied under laboratory conditions. Sorption-desorption experiments were conducted in soils...

  3. 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...

  4. Electrokinetic remediation of fluorine-contaminated soil: conditioning of anolyte.

    PubMed

    Kim, Do-Hyung; Jeon, Chil-Sung; Baek, Kitae; Ko, Sung-Hwan; Yang, Jung-Seok

    2009-01-15

    The feasibility of anolyte conditioning on electrokinetic remediation of fluorine-contaminated soil was investigated with a field soil. The initial concentration of fluorine, pH and water content in the soil were 414mg/kg, 8.91 and 15%, respectively. Because the extraction of fluorine generally increased with the soil pH, the pH of the anode compartment was controlled by circulating strong alkaline solution to enhance the extraction of fluorine during electrokinetic remediation. The removal of fluorine increased with the concentration of the alkaline solution and applied current density and fluorine removed up to 75.6% within 14 days. Additionally, anolyte conditioning sharply increased the electro-osmotic flow, which enhanced the removal of fluorine in this study. In many respects, anolyte conditioning in electrokinetic remediation of fluorine-contaminated soil will be a promising technology.

  5. 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.

  6. 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.

  7. Soil contamination with emissions of non-ferrous metallurgical plants

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.; Plekhanova, I. O.; Prokopovich, E. V.; Savichev, A. T.

    2011-02-01

    The upper soil horizons are strongly contaminated in the area influenced by the Mid-Urals copper smelter. In the technogenic desert and impact zones, the contents of a number of elements (Cu, Zn, As, Pb, P, and S) by many times exceed their clarke values and the maximum permissible concentrations (or provisional permissible concentrations). The degree of technogeneity (Tg) for these elements is very high in these zones. In the far buffer zone, Tg is about zero for many elements and increases up to Tg = 27-42% for four heavy elements (Cu, Zn, Pb, and As) and up to 81-98% for P and S. The buffer capacity of the humus horizon depends on the soil's location within the technogeochemical anomaly and also on the particular pollutant. In the impact zone, it is equal to 70-77% for lead and arsenic, although other technogenic elements (Zn, Cr, S, and P) are poorly retained and readily migrate into the deeper horizons (the buffer capacity is equal to 14-25%). Nearly all the heavy metals enter the soil in the form of sulfides. The soils in the area affected by the Noril'sk mining and smelting metallurgical enterprise are subdivided into two groups according to the degree of their contamination, i.e., the soils within Noril'sk proper and the soils in its suburbs to a distance of 4-15 km. The strongest soil contamination is recorded in the city: the clarke values are exceeded by 287, 78, 16, 4.1, and 3.5 times for Cu, Ni, Cr, Fe, and S, respectively. The major pollutants enter the soil from the ferruginous slag. The soil's contamination degree is lower in the suburbs, where heavy metal sulfides reach the soils with the aerial emission from the enterprise.

  8. Behaviour of polychlorinated biphenyls contaminating soil near Zadar.

    PubMed

    Kobasić, Vedranka Hodak; Picer, Mladen; Picer, Nena; Sraka, Mario; Kovac, Tatjana

    2006-09-01

    This study analysed PCB-contaminated natural soil excavated from an area adjacent to an electrical transformer station in Zadar, Croatia. For one year, PCB concentrations were measured in the soil and leachate water under natural climatic conditions. After 12 months, a negligible quantity of Aroclor 1248 (0.024% in average) and a total of seven key PCB congeners (IUPAC No: PCB-28, PCB-52, PCB-101, PCB-118, PCB-138, PCB-153, and PCB-180) were leached through the soils into water collected under lysimeters (0.032% in average). Although the amounts of leached PCBs were relatively small, their range 2 microg L(-1) to 15 microg L(-1) substantially exceeds the maximal allowed concentration of total PCBs in fishponds which is 1 ng L(-1). Soil samples were taken on two occasions from three depths from each lysimeter. The distribution of total PCBs as Aroclor 1248 equivalents and seven individual PCB congeners was determined within soil layers before and after planting seeds. In all soil plots the content of total seven PCBs and some individual PCB congeners in the surface soil layers significantly decreased. The total content of the seven PCB congeners in the surface soil layer of all soil plots decreased between 19.0% (soil plot 2) and 47.6% (soil plot 1) and in the middle soil layer between 8.1% (soil plot 4) and 37.4% (soil plot 1). PCB-28 and PCB-52 showed the highest percent of removal in all soil plots after 12 months of the experiment. The most important mechanism of removal of "lighter" congeners may be evaporation from the soil surface. Generally, our results showed that the PCBs accumulated in the deepest level of the soil, probably due to vertical transport and decreased evaporation. Some of the PCB content was lost to their degradation in the rhizosphere of the plants growing on the analysed soil plots. PMID:17121001

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. [Rhizosphere enhanced remediation of petroleum contaminated soil].

    PubMed

    Lu, Mang; Zhang, Zhong-zhi; Sun, Shan-shan; Qiao, Wei; Liu, Xiao

    2009-12-01

    The effects of growing tall fescue on the biodegradation of hydrocarbons was studied in laboratory scale pots. Degradation of hydrocarbons as well as microbial counts, soil fluorescein diacetate activity, catalase activity and dehydrogenase activity were determined. The results showed that, in the rhizosphere soil system, total petroleum hydrocarbons disappeared faster than that in unvegetated pots soil. After 10 weeks, 11.8% and 27.4% of spiked petroleum hydrocarbons disappeared from the bulk and rhizosphere soils respectively. Abiotic loss of petroleum hydrocarbons by evaporation was of minor significance in the test. The microbial plate counts and soil enzyme activities were significantly higher in the rhizosphere than in the bulk soil. Petroleum compounds had significant effect on fluorescein diacetate hydrolyzing activity. Vegetation resulted in significantly greater first-order decay constants compared to the unvegetated control. Oxygenated polycyclic aromatic hydrocarbons that were present in the soil were generally degraded more slowly than the parent compounds, suggesting that they were formed during the treatment or that they are more persistent. Four oxidation products of polycyclic aromatic hydrocarbons, 1-acenaphthenone, 9-fluorenone, anthraquinone, and benzfluorenone were found at significantly higher concentrations at the end of the study.

  15. 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.

  16. 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

  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.

  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. Bioremediation of di(2-ethylhexyl)phthalate in contaminated soil

    SciTech Connect

    Yu, J.J.; Ward, O.P.

    1995-12-31

    An efficient process has been developed for bioremediation of di(2-ethylhexyl) phthalate (DEHP) using soil tilling. The process involves application of a proprietary nutrient formulation and bioaugmentation with a site-specific DEHP-degrading inoculum. Laboratory feasibility studies were conducted to evaluate different factors that affect the process. The effects of moisture content, inoculum, nutrient rate, and initial DEHP concentration on biodegradation were investigated. A novel supplementary system--treatment system 2--was shown to accelerate DEHP degradation and facilitate remediation of residual persistent contaminant DEHP, which may be tightly bound to soil. In pilot studies, DEHP-contaminated soils were remediated to below 100 mg/kg in 70 to 80 days. Use of treatment system 2 resulted in reduction of contaminants to less than 15 mg/kg.

  1. [Feasibility of applying ornamental plants in contaminated soil remediation].

    PubMed

    Liu, Jia-Nü; Zhou, Qi-Xing; Sun, Ting; Wang, Xiao-Fei

    2007-07-01

    Phytoremediation is one of the effective ways in resolving problems of contaminated soils, but limited hyperaccumulation plant species were reported and documented. This shortage could be offset if remediation plants can be screened out from various ornamental plants. In addition, such doing can beautify the environment while bring some economic effects. Starting from the importance of phytoremediation, this paper generalized the characters and standards of remediation plants. Through describing the resources of ornamental plants and their functions on environmental protection, particularizing their superiorities to other plants, and analyzing their endurance, accumulation traits and remediation types, the feasibility of applying ornamental plants in the practices of contaminated soil remediation was discussed. To screening out hyperaccumulators from ornamental plants would be an entirely new research area in the remediation of contaminated soils.

  2. Low-cost in-soil organic contaminant sensor

    NASA Astrophysics Data System (ADS)

    Brossia, Charles E.; Wu, Samuel C.

    1991-03-01

    The First Omega Group Inc. has developed a low cost optical fiber sensing technique for detecting the presence of oils gasoline organic solvents and other oily contaminants in soils. The sensing means consists of a continuous optical fiber having a portion of its surface specially processed to render it sensitive to the presence of soil contandnants. The processed area of the fiber is positioned within the environment that is at risk of contaniination. Contact by a contaminant with the processed area of the optical fiber changes the attenuation of infrared light through the processed area in a characteristic way and in real time. The change in light attenuation is detected using a conven tional photo detector to provide indication of contamination within the soil.

  3. 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.

  4. 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.

  5. Phytoremediation of contaminated soils: Progress and promise

    SciTech Connect

    Cunningham, S.D.; Berti, D.R.; Dupont, E.I.

    1993-12-31

    {open_quotes}Phytoremediation{close_quotes} refers to the use of green plants, including plant-associated microflora, to remediated contaminated sites. The talk addresses the remediation of solids only, although green-plant based systems are well established in waste-water treatment and air pollution control. Phytoremediation has potential significant economic, regulatory and aesthetic advantages over many engineering-based solutions. The technology can be targeted to both inorganic and organic contaminants. The focus of this talk will be on lead (Pb). A brief overview of activities in organic remediation will be included at the end of the talk.

  6. 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

  7. 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)

  8. 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.

  9. 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.

  10. Phenanthrene and pyrene oxidation in contaminated soils using Fenton's reagent.

    PubMed

    Silva, Paula Tereza de Souza E; Silva, Valdinete Lins da; Neto, Benício de Barros; Simonnot, Marie-Odile

    2009-01-30

    Fenton's reagent has shown its applicability to oxidizing these biorefractory organic contaminants. The purpose of this contribution was to investigate the influence of operating parameters on the process efficiency for soil highly contaminated by PAHs. Five variables were selected: pH, reaction time, UV irradiation, hydrogen peroxide concentration and Fe (II) amendment. Their effects on the oxidation of (i) phenanthrene and on (ii) phenanthrene and pyrene present in freshly contaminated soil samples were studied through batch reactor experiments following factorial designs. For phenanthrene oxidation run with a soil contaminated at 700 mg kg(-1), one set of variables enabled us to reach a residual concentration lower than 40 mg kg(-1) (Dutch legislation threshold). The most important factor was the reaction time, followed at a certain distance by UV irradiation, Fe (II), H(2)O(2) concentration and pH, this last variable being the least significant. The possibility of operating without pH adjustment is of importance in the treatment at the field scale. This shows the feasibility of photo-Fenton-like oxidation for the treatment of soil highly contaminated with PAH and the relative importance of the process variables. PMID:18524479

  11. 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

  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. 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.

  14. 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

  15. The potential inhalation hazard posed by dioxin contaminated soil

    SciTech Connect

    Paustenbach, D.J.; Sarlos, T.T.; Lau, V.; Finley, B.L.; Jeffrey, D.A.; Ungs, M.J. )

    1991-10-01

    Mathematical models and field data were used to estimate the airborne concentrations of 2,3,7,8 tetratchlorodibenxo-p-dioxin (TCDD) vapor and particulates which could originate from soil containing 100 ppb TCDD. The model of Jury et al. (1983) and the box approach were used to predict the concentration of TCDD vapor from soil. These results indicate that the concentration predicted by the Jury et al. model are about 1,000 fold greater than which actually occur. The inability of the Jury model to accurately estimate the rate of violation of TCDD from soil is probably because the TCDD was applied to the sol in a formulated state where it could easily migrate below the surface. A recent modification of the Jury model (1990) suggests that a 5-50 mm layer of clean soil will significantly retard (or eliminate) the vapor hazard posed by TCDD contaminated soil. The risks due to fugitive dust will always be greater than the vapor hazard, but for soil concentrations of 100 ppb the cancer risk should be less than 10{sup {minus}6}. Since few sites have average soil concentrations as high as 100 ppb, this nearly worst case analysis indicates that inhalation will rarely, if ever, be a significant route of exposure to TCDD-contaminated soil.

  16. 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.

  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. 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.

  19. 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

  20. 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...

  1. 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...

  2. 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...

  3. 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.

  4. 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

  5. Radionuclide contaminated soil: Laboratory study and economic analysis of soil washing. Final report

    SciTech Connect

    Fuhrmann, M.; Zhou, H.; Patel, B.; Bowerman, B.; Brower, J.

    1996-05-20

    The objective of the work discussed in this report is to determine if soil washing is a feasible method to remediate contaminated soils from the Hazardous Waste Management Facility (HWMF) at Brookhaven National Laboratory (BNL). The contaminants are predominantly Cs-137 and Sr-90. The authors have assumed that the target activity for Cs-137 is 50 pCi/g and that remediation is required for soils having greater activities. Cs-137 is the limiting contaminant because it is present in much greater quantities than Sr-90. This work was done in three parts, in which they: estimated the volume of contaminated soil as a function of Cs-137 content, determined if simple removal of the fine grained fraction of the soil (the material that is less than 0.063 mm) would effectively reduce the activity of the remaining soil to levels below the 50 pCi/g target, assessed the effectiveness of chemical and mechanical (as well as combinations of the two) methods of soil decontamination. From this analysis the authors were then able to develop a cost estimate for soil washing and for a baseline against which soil washing was compared.

  6. Contaminated Soil Volume Estimation at the Maywood Site - 12292

    SciTech Connect

    Johnson, Robert; Quinn, John; Durham, Lisa; Moore, James; Hays, David

    2012-07-01

    As part of the ongoing remediation process at the Maywood Formerly Utilized Sites Remedial Action Program properties, Argonne National Laboratory assisted the U.S. Army Corps of Engineers (USACE) New York District in revising contaminated soil volume estimates for the remaining areas of the Stepan/Sears properties that require soil remediation. As part of the volume estimation process, an initial conceptual site model (ICSM) was prepared for the entire site that captured existing information (with the exception of soil sampling results) pertinent to the possible location of surface and subsurface contamination above cleanup requirements. This ICSM was based on historical anecdotal information, aerial photographs, and the logs from several hundred soil cores that identified the depth of fill material and the depth to bedrock under the site. Specialized geostatistical software developed by Argonne was used to update the ICSM with historical sampling results and down-hole gamma survey information for hundreds of soil core locations; both sampling results and down-hole gamma data were coded to identify whether the results indicated the presence of contamination above site cleanup requirements. Significant effort was invested in developing complete electronic data sets for the site by incorporating data contained in various scanned documents, maps, etc. The updating process yielded both a best guess estimate of contamination volumes and upper and lower bounds on the volume estimate that reflected the estimate's uncertainty. The site-wide contaminated volume estimate (with associated uncertainty) was adjusted to reflect areas where remediation was complete; the result was a revised estimate of the remaining soil volumes requiring remediation that the USACE could use for planning. Other environmental projects may benefit from this process for estimating the volume of contaminated soil. A comparison of sample and DHG results for various stations with the site ICSM provides

  7. Role of soil rhizobacteria in phytoremediation of heavy metal contaminated soils*

    PubMed Central

    Jing, Yan-de; He, Zhen-li; Yang, Xiao-e

    2007-01-01

    Heavy metal pollution of soil is a significant environmental problem and has its negative impact on human health and agriculture. Rhizosphere, as an important interface of soil and plant, plays a significant role in phytoremediation of contaminated soil by heavy metals, in which, microbial populations are known to affect heavy metal mobility and availability to the plant through release of chelating agents, acidification, phosphate solubilization and redox changes, and therefore, have potential to enhance phytoremediation processes. Phytoremediation strategies with appropriate heavy metal-adapted rhizobacteria have received more and more attention. This article paper reviews some recent advances in effect and significance of rhizobacteria in phytoremediation of heavy metal contaminated soils. There is also a need to improve our understanding of the mechanisms involved in the transfer and mobilization of heavy metals by rhizobacteria and to conduct research on the selection of microbial isolates from rhizosphere of plants growing on heavy metal contaminated soils for specific restoration programmes. PMID:17323432

  8. 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).

  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. 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.

  11. 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

  12. 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.

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  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. 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

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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

  5. Metal ion leaching from contaminated soils: Model calibration and application

    SciTech Connect

    Ganguly, C.; Rabideau, A.J.; Matsumoto, M.R.; Van Benschoten, J.E.

    1998-12-01

    A previously developed model that describes leaching of heavy metals from contaminated soils is applied to four hazardous-waste-site soils contaminated with Pb. Processes included in the model are intraparticle diffusion, rate expressions for irreversibly and reversibly sorbed fractions, and metal complexation by ions in solution. The model is calibrated using laboratory experimental data in the pH 1--3 range, liquid-to-solid mass ratios from 5 to 20, and leaching times of 24 h. Parameters for the model are estimated through a combination of independent experiments, literature correlations, and mathematical optimization. Equilibrium data were used to estimate site density and an adsorption equilibrium constant. Two kinetic rate coefficients, a particle tortuosity factor, and a distribution coefficient ({alpha}{sub a}) that defined the amount of Pb in two contaminant fractions were adjusted to match kinetic leaching data. Using one set of parameter estimates for each soil, the model successfully simulated experimental data collected under different leaching conditions. The fraction of Pb associated with easily leachable, irreversibly sorbed fraction (1 {minus} {alpha}{sub a}) provides some insight to the geochemical distribution of Pb in the soils tested. The model is used to explore effects of process variables such as liquid-to-solid ratio and sequential washes. The model should be useful for simulating ex-situ soil washing processes and may, with further development, have applications for in-situ flushing processes.

  6. 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...

  7. Heavy metals contamination of soils surrounding waste deposits in Romania

    NASA Astrophysics Data System (ADS)

    Matache, M.; Rozylowicz, L.; Ropota, M.; Patroescu, C.

    2003-05-01

    Soils contamination with heavy metals is one of the most severe aspects of environmental pollution in Romania, independently of the origin sources (domestic or industrial activities) or type of disposal (organised landfill or hazardous deposits)[l-2]. This fact is the consequence of the poor state of the existing waste deposits in Romania and of the significant costs involved by the establishing of a new landfill according with the international regulations. The present study is trying to emphasise the contamination of soils surrounding different categories of waste deposits (sewage sludge ponds, domestic and industrial waste landfills, hillocks, sterile deposits) from various regions of Romania. Some case studies show a special interest being localise in a protected area (Iron Gates Natural Park). In order to quantify the concentration of metals like Cd, Cr, Cu, Pb, Zn, Ni, Mo in soil samples, analysis were performed using Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES). Romanian standards were used as reference values[3].

  8. 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

  9. 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.

  10. [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.

  11. Soil slurry reactors for the assessment of contaminant biodegradation

    NASA Astrophysics Data System (ADS)

    Toscano, G.; Colarieti, M. L.; Greco, G.

    2012-04-01

    Slurry reactors are frequently used in the assessment of feasibility of biodegradation in natural soil systems. The rate of contaminant removal is usually quantified by zero- or first-order kinetics decay constants. The significance of such constants for the evaluation of removal rate in the field could be questioned because the slurry reactor is a water-saturated, well-stirred system without resemblance with an unsaturated fixed bed of soil. Nevertheless, a kinetic study with soil slurry reactors can still be useful by means of only slightly more sophisticated kinetic models than zero-/first-order decay. The use of kinetic models taking into account the role of degrading biomass, even in the absence of reliable experimental methods for its quantification, provides further insight into the effect of nutrient additions. A real acceleration of biodegradation processes is obtained only when the degrading biomass is in the growth condition. The apparent change in contaminant removal course can be useful to diagnose biomass growth without direct biomass measurement. Even though molecular biology techniques are effective to assess the presence of potentially degrading microorganism in a "viable-but-nonculturable" state, the attainment of conditions for growth is still important to the development of enhanced remediation techniques. The methodology is illustrated with reference to data gathered for two test sites, Oslo airport Gardermoen in Norway (continuous contamination by aircraft deicing fluids) and the Trecate site in Italy (aged contamination by crude oil spill). This research is part of SoilCAM project (Soil Contamination, Advanced integrated characterisation and time-lapse Monitoring 2008-2012, EU-FP7).

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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,...

  17. 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

  18. 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

  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 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...

  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. 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

  2. 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.

  3. 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

  4. [An approach to the establishment of remediation standards for contaminated soils].

    PubMed

    Chao, Lei; Zhou, Qixing; Chen, Su

    2006-02-01

    With the rapid development of remediation technology for contaminated soils in China, remediation standard has become a bottleneck in judging the effects of this technology. In this paper, some suggestions on the establishment of remediation standards for contaminated soils, e.g., choice of contaminants, methods of detection, classification of contaminated soils, protection of groundwater, and assessment of toxicological risks were put forward, based on the analysis of the disadvantages of Soil Environmental Quality Standard.

  5. Application of autoradiographic techniques for contaminant distribution studies in soils

    NASA Astrophysics Data System (ADS)

    Povetko, Oleg G.

    In order to determine the physical location of contaminants in soil, two solidified soil "thin" sections, which preserve the undisturbed structural characteristics of the original soil, containing weapons-grade plutonium from the Rocky Flats Environmental Test Site were prepared. Two autoradiographic methods were used in radionuclide mapping: contact autoradiography using CR-39RTMplastic alpha track detectors and neutron-induced autoradiography that produced fission fragment tracks in LexanRTM plastic detectors. The combination of the two autoradiographic methods distinguished alpha-emitting particles of natural U, from 239+240Pu and non-fissile alpha-emitters. The locations of 990 alpha "stars" caused by plutonium "hot particles" in two soil sections were recorded, particles were sized, their size-frequency and depth distributions were analyzed. Several large colloidal conglomerates of "hot particles" were found in soil profiles. One such conglomerate with a geometric size of about 500 mum contained over 94% of the total recorded contaminant alpha activity in the sample. It was found that the upper 6.5 cm of soil contained 20% of all recorded particles (mean equivalent size 0.35 mum). The deeper portion of the surface 6.5 cm soil layer contained 80% of the particles (with mean equivalent size 0.25 mum). The average specific activity (SA) for 989 hot particles (with the conglomerate of the particles excluded) with equivalent diameters over 80 nm was found to be greater than 23.9 Bq g-1 (about 90% of the overall average SA). For dissolved and defragmented (below 80 nm of equivalent diameter) actinide particles, SA was found smaller than 2.9 Bq g-1. Over 99% of the total actinide contaminant activity in the analyzed soil sample (with the conglomerate of the particles included) was found in particles with equivalent diameters over 0.08 mum. It suggests that larger particles of plutonium oxide moved down more slowly than smaller ones and no significant breakup of

  6. Testing amendments for remediation of military range contaminated soil.

    PubMed

    Siebielec, Grzegorz; Chaney, Rufus L

    2012-10-15

    Military range soils are often strongly contaminated with metals. Information on the effectiveness of remediation of these soils is scarce. We tested the effectiveness of compost and mineral treatments for remediation and revegetation of military range soil collected in Aberdeen, MD. The soil was barren due to zinc (Zn) phytotoxicity while lead (Pb) posed a substantial risk to soil biota, wildlife and humans through various pathways. Seven treatments were tested: untreated control, agricultural NPK fertilization, high phosphate fertilization plus agricultural rates of NK, CaCO(3), "Orgro" biosolid compost, "Orgro" + CaCO(3), "Orgro" + CaCO(3) + Mn sulfate. All compost treatments alleviated Zn phytotoxicity to tall fescue; however compost combined with liming reduced plant Zn content up to 158-162 mg kg(-1). Compost added with lime reduced Pb in-vitro bioaccessibility from 32.5 to 20.4% of total Pb and was the most effective among the tested treatments. The study revealed the effectiveness of biosolids compost and lime mixture in the rapid stabilization of metals and revegetation of military range contaminated soils. The persistence of the remediation needs to be, however, confirmed in the long-term field study.

  7. Process for reduction of volume of contaminated soil by compaction

    SciTech Connect

    Johanan, W.L.

    1994-12-31

    Burial costs for low-level radioactive waste are assessed by the volume of the waste. These costs are presently at $10 per cubic foot and will continue to increase with time. A reduction in waste volume can be directly converted to a reduction in burial costs. A large amount of low-level contaminated soil exists throughout the DOE complex. The Nuclear Complex Modernization Task Force has identified over 5 million cubic feet of contaminated soil for eventual clean-up at the Mound site ($50,000,000 to bury at FY 1991 costs). By using a combination of a rock separator (trommel), crusher, clay soil compactor, automatic loading system, specially designed dust enclosures, and specifically designed containers for both on-site haulage and shipment to the Nevada Test Site (NTS), the total waste volume, and burial cost, can be reduced by up to 30% by compacting the soil into high-density bricks (depending upon the compaction quality of the soil). Several tests have been performed on Mound`s cold on-site soils, with resulting densities of 131 pounds per cubic foot. When this is compared to normal LSA metal box filling of 80--90 pounds per cubic foot, one can readily see the savings.

  8. 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.

  9. [Anolyte enhanced electrokinetic remediation of fluorine-contaminated soils].

    PubMed

    Zhu, Shu-Fa; Yan, Chun-Li; Dong, Tie-You; Tang, Hong-Yan

    2009-07-15

    An experimental study was carried out in order to determine the characteristics of migration and its influencing factor of soil fluorine in the electrokinetic process under different applied voltage and concentration of anolyte. The feasibility of anolyte enhanced on electrokinetic remediation of fluorine-contaminated soil was analyzed. The results show that when deionized water is used as anolyte with the 1.0 V/cm voltage gradient, the cumulative mass of fluorine in catholyte and anolyte are 8.2 mg and 47.7 mg respectively and the removal rate of fluorine is only 8.8%. Anolyte enhanced electrokinetic process can promote effectively the migration of fluoride in soil. When 0.02 mol/L NaOH solutionis employed as the anolyte, the removal rates are 25.9%, 31.2% and 47.3% with 1.0, 1.5 and 2.0 V/cm voltage gradient respectively. As the concentration of anolyte increased to 0.1 mol/L, the removal rates are 55.4%, 61.1% and 73.0%. The electromigration is the main transport mechanism and the electroosmotic flow has an effect on the migration of fluorine in soil. The voltage gradient and the concentration of anolyte are the main factors influencing the removal rate of fluorine in soil. Appropriate anolyte enhanced electrokinetic method can be applied to remediate fluorine from contaminated soil.

  10. Impact of transgenic tobacco on trinitrotoluene (TNT) contaminated soil community.

    PubMed

    Travis, Emma R; Hannink, Nerissa K; Van der Gast, Christopher J; Thompson, Ian P; Rosser, Susan J; Bruce, Neil C

    2007-08-15

    Environmental contamination with recalcitrant toxic chemicals presents a serious and widespread problem to the functional capacity of soil. Soil bacteria play an essential role in ecosystem processes, such as nutrient cycling and decomposition; thus a decrease in their biomass and community diversity, resulting from exposure to toxic chemicals, negatively affects the functioning of soil. Plants provide the primary energy source to soil microorganisms and affect the size and composition of microbial communities, which in turn have an effect on vegetation dynamics. We have found that transgenic tobacco plants overexpressing a bacterial nitroreductase gene detoxify soil contaminated with the high explosive 2,4,6-trinitrotoluene (TNT), with a significantly increased microbial community biomass and metabolic activity in the rhizosphere of transgenic plants compared with wild type plants. This is the first report to demonstrate that transgenic plants engineered for the phytoremediation of organic pollutants can increase the functional and genetic diversity of the rhizosphere bacterial community in acutely polluted soil compared to wild type plants. PMID:17874797

  11. 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

  12. [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

  13. [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.

  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.

  15. Remediation of contaminated soils and sediments using Daramend bioremediation

    SciTech Connect

    Burwell, S.W.; Bucens, P.G.; Seech, A.G.

    1996-05-01

    Soils and sediments containing polyaromatic hydrocarbons (PAH), petroleum hydrocarbons, heavy oils, chlorinated phenols, pesticides, herbicides and phthalates, either individually or in combination, have been difficult to remediate in the past. Not only the species of contaminant, but contaminant concentrations were roadblocks to successful use of bioremediation. Daramend{sup Tm} remediation has removed many of these obstacles through extensive research. Bench-scale, pilot-scale and full-scale demonstrations have been conducted at a variety of industrial sites. At a manufactured gas site, 295 days of Daramend remediation reduced concentrations of chrysene and fluoranthene from 38.9 mg/kg to 5.9 mg/kg and 84.6 mg/kg to 7.8 mg/kg respectively. Elsewhere, the total PAH concentration in a silty soil was reduced from 1,442 mg/kg to 36 mg/kg. Concentrations of even the most refractory PAHs (e.g. pyrene, benzo(a)pyrene) were reduced to below the established clean-up guidelines. Total petroleum hydrocarbons (diesel fuel) have also been reduced from 8,700 mg/kg to 34 mg/kg after 182 days of treatment. Similarly, in a clay soil contaminated by crude oil processing, the concentrations of high molecular weight aliphatic hydrocarbons were rapidly reduced (138 days) to below the remediation criteria. Demonstrations with wood treatment site soils have proven Daramend remediation effective in enhancing the target compound degradation rates. Soils containing 2170 mg PCP/kg were shown to contain only 11 mg PCP/kg after 280 days of Darmend remediation. The issue of toxicity of soil containing increased amounts of pentachlorophenols was solved. Performance data collected during these projects indicate that Daramend remediation provides a cost effective method for clean-up of soils and sediments containing a variety of organic compounds.

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. [Phytoavailability and chemical speciation of cadmium in different Cd-contaminated soils with crop root return].

    PubMed

    Zhang, Jing; Yu, Ling-Ling; Xin, Shu-Zhen; Su, De-Chun

    2013-02-01

    Pot experiments were conducted under greenhouse condition to investigate the effects of crop root return on succeeding crops growth, Cd uptake and soil Cd speciation in Cd-contaminated soil and artificial Cd-contaminated soil. The results showed that the amount of root residue returned to soil by corn and kidney bean growth successive for 3 times was 0.4%-1.1%. The Cd returned to soil by root residue was 1.3%-3.5% to the total soil Cd. There was no significant difference in the shoot dry weights of winter wheat and Chinese cabbage grown on the 2 Cd-contaminated soils with and without root return. While Cd concentration of Chinese cabbage increased significantly in the Cd-contaminated soil with corn or kidney bean root return. Light fraction of soil organic matter increased with root return in both of the Cd-contaminated soils. The percentage of Cd in the light fraction of soil organic matter increased with root return in the artificial Cd-contaminated soil. Soil carbonates-bound Cd concentration decreased significantly with corn root return in the Cd-contaminated soil. Soil exchangeable Cd concentration decreased and soil Fe-Mn oxide-bound Cd concentration increased significantly with kidney bean root return in the artificial Cd-contaminated soil.

  4. Migration of contaminated soil and airborne particulates to indoor dust.

    PubMed

    Layton, David W; Beamer, Paloma I

    2009-11-01

    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, were 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.

  5. 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

  6. 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.

  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. Sources of arsenic and fluoride in highly contaminated soils causing groundwater contamination in Punjab, Pakistan.

    PubMed

    Farooqi, Abida; Masuda, Harue; Siddiqui, Rehan; Naseem, Muhammad

    2009-05-01

    Highly contaminated groundwater, with arsenic (As) and fluoride (F(-)) 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(-) 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(-) (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(-) 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(-) and As adsorbed on the soil, thus releasing it into the local groundwater.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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)

  18. Assessment of the ecotoxic potential of soil contaminants by using a soil-algae test.

    PubMed

    Hammel, W; Steubing, L; Debus, R

    1998-01-01

    To assess the ecotoxic potential of soil contaminants, a test with the soil alga Chlorococcum infusionum has been developed, enabling investigations of soil pollutions with soluble and fairly soluble chemicals. Three soil types artificially contaminated with Sb compounds and five soils from a historical mining area, which were highly polluted with Sb, As, Hg, and Cu, were used as test soils. For antimony, EC50 values from 125 mg/kg up to > 1000 mg/kg, depending on soil type, were determined. Two of five soils from the mining area caused toxic effects. Additionally, aqueous extracts of all soils were exposed in established tests (daphnid, alga, bacterium). In contrast with the soil-algae test, no toxic effects were found. Aquatic tests with SbO/K tartrate were performed to point out the toxicity of antimony. The following EC50 values in milligrams of Sb per liter were determined: Scenedesmus subspicatus, 59 mg/liter; Chlorococcum infusionum, 43 mg/liter; Daphnia magna, 8 mg/liter; and Vibrio fisheri, 7 mg/liter.

  19. 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.

  20. Evaluation of solidification/stabilization for treating explosives contaminated soils

    SciTech Connect

    Cullinane, M.J. Jr.; Channell, M.

    1996-12-31

    The success of solidification/stabilization (S/S) for treating explosives contaminated soils was evaluated using a variety of physical, chemical, and contaminant release testing methods. The analytes of concern included explosives and their degradation products (TNT, RDX, HMX, 2, 4-Dinitrotoluene, 2,6-dinitrotoluene, 2,4,6-Trinitrotoluene, 2-Amino-4,6-Dinitrotoluene, 4-Amino-2,6-Dinitrobenzene, 2,4-Dinitrotoluene) and PAH`s (Benzo(a)anthracene, Benzo(b)fluoranthene, Benzo(k)fluoranthene, Benzo(a)pyrene, Chrysene, Dibenz(a,h) anthracene, and Ideno (1,2,3-cd)pyrene). All Toxicity Characteristic Leaching Procedure (TCLP) leachate analytes, except 2-Am-4,6-TNT was reduced approximately 97%. The release of 2,4-DNT was also significantly reduced. The results of the Sequential Batch Leach Test (SBLT) were mixed. The PAH compounds were not identified above detectable limits in the leachates from either the untreated soil or the treated soils. Release of 2,4,6-TNT was reduced to undetectable. However, other explosives related compounds (2-Am-4, 6-DNT) were identified in the leachates from the treated soils that were not identified in the untreated soil. Organic transformations in the highly alkaline environment associated with S/S or sample heterogeneity are suspected to cause this phenomena.

  1. 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

  2. Evaluation of biosurfactants for crude oil contaminated soil washing.

    PubMed

    Urum, Kingsley; Pekdemir, Turgay

    2004-12-01

    An evaluation of the ability of aqueous biosurfactant solutions (aescin, lecithin, rhamnolipid, saponin and tannin) for possible applications in washing crude oil contaminated soil was carried out. The biosurfactants behaviour in soil-water, water-oil and oil-soil systems (such as foaming, solubilization, sorption to soil, emulsification, surface and interfacial tension) was measured and compared with a well-known chemical surfactant (sodium dodecyl sulphate, SDS) at varying concentrations. Results showed that the biosurfactants were able to remove significant amount of crude oil from the contaminated soil at different solution concentrations for instance rhamnolipid and SDS removed up to 80% oil and lecithin about 42%. The performance of water alone in crude oil removal was equally as good as those of the other biosurfactants. Oil removal was due to mobilization, caused by the reduction of surface and interfacial tensions. Solubilization and emulsification effects in oil removal were negligible due to the low crude oil solubilization of 0.11%. Therefore, these studies suggest that knowledge of surfactants' behaviour across different systems is paramount before their use in the practical application of oil removal.

  3. Phytoremediation of soils contaminated with toxic elements and radionuclides

    SciTech Connect

    Cornish, J.E.; Goldberg, W.C.; Levine, R.S.; Benemann, J.R.

    1995-12-31

    At many US Department of Energy (US DOE) facilities and other sites, surface soils over relatively large areas are contaminated with heavy metals, radionuclides, and other toxic elements, often at only a relatively small factor above regulatory action levels. Cleanup of such sites presents major challenges, because currently available soil remediation technologies can be very expensive. In response, the US DOE`s Office of Technology Development, through the Western Environmental Technology Office, is sponsoring research in the area of phytoremediation. Phytoremediation is an emerging technology that uses higher plants to transfer toxic elements and radionuclides from surface soils into aboveground biomass. Some plants, termed hyperaccumulators, take up toxic elements in substantial amounts, resulting in concentrations in aboveground biomass over 100 times those observed with conventional plants. After growth, the plant biomass is harvested, and the toxic elements are concentrated and reclaimed or disposed of. As growing, harvesting, and processing plant biomass is relatively inexpensive, phytoremediation can be a low-cost technology for remediation of extensive areas having lightly to moderately contaminated soils. This paper reviews the potential of hyper- and moderate accumulator plants in soil remediation, provides some comparative cost estimates, and outlines ongoing work initiated by the US DOE.

  4. 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.

  5. 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 ...

  6. 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 ...

  7. 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…

  8. 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

  9. Intrasite sampling of Hong Kong soils contaminated by Caesium-137.

    PubMed

    Ruse, M E; Peart, M R

    2000-07-01

    Previous measurements of soil contamination by Caesium-137 (137Cs) in Hong Kong have been used both to estimate background levels prior to the construction of the Guangdong Nuclear Power Station (GNPS) at Daya Bay and to evaluate health hazards arising from the radionuclide. These measurements are reviewed and contrasted with recent advances in understanding of 137Cs distribution in soil. Preliminary research findings are used to illustrate the microscale variability of 137Cs in the Hong Kong environment and to suggest intrasite sampling methods for establishing suitable reference values.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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).

  15. PRACTICAL DIAGNOSIS OF BIOSTIMULATION FOR VOC CONTAMINATED SOIL AND GROUNDWATER

    NASA Astrophysics Data System (ADS)

    Suzuki, Keiichi; Ando, Takuya; Ito, Yoshitaka; Sato, Takeshi

    Biostimulation has been widely used as a remediation of soil and groundwater contaminated by chlorinated volatile organic compounds (VOC). The chemical and biological systems in actual field are so complicated that it is hard to know the mathematical modeling parameters prior to laboratory tests using contaminated soil and groundwater sampled from specific site. The paper addresses an diagnostic method to evaluate the parameters controlling the lag time an d the chemical reaction rate which are essential to predict efficiency of biostimulation in actual field. In this paper, laboratory test results of thirtyseven sites are stochastically reanalyzed to make clear the dependency of the lag time and the chemical reaction rate on groundwater quality indices, such as DO, ORP, pH, etc.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. Spectral induced polarization (SIP) measurement of NAPL contaminated soils

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    The potential applicability of spectral induce polarization (SIP) as a tool to map NAPLs (non aqueous phase liquids) contaminants at the subsurface lead researchers to investigate the electric signature of those contaminant on the spectral response. However, and despite the cumulative efforts, the effect of NAPL on the electrical properties of soil, and the mechanisms that control this effect are largely unknown. In this work a novel experiment is designed to further examine the effect of NAPL on the electrical properties of partially saturated soil. The measurement system that used is the ZEL-SIP04 impedance meter developed at the Forschungszentrum Julich, Germany. The system accurately (nominal phase precision of 0.1 mrad below 1 kHz) measures the phase and the amplitude of a material possessing a very low polarization (such as soil). The sample holder has a dimension of 60 cm long and 4.6 cm in diameter. Current and potential electrodes were made of brass, and while the current electrodes were inserted in full into the soil, the contact between the potential electrode and the soil was made through an Agarose bridge. Two types of soils were used: clean quartz sand, and a mixture of sand with clean Bentonite. Each soil (sandy or clayey) was mixed with water to get saturation degree of 30%. Following the mixture with water, NAPL was added and the composite were mixed again. Packing was done by adding and compressing small portions of the soil to the column. A triplicate of each mixture was made with a good reproducible bulk density. Both for the sandy and clayey soils, the results indicate that additions of NAPL decrease the real part of the complex resistivity. Additionally, for the sandy soil this process is time depended, and that a further decrease in resistivity develops over time. The results are analyzed considering geometrical factors: while the NAPL is electrically insulator, addition of NAPL to the soil is expected to increase the connectivity of the

  1. 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.

  2. 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.

  3. 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

  4. In-Situ Containment and Extraction 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.

  5. 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.

  6. 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.

  7. 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.

  8. Assessing soil and groundwater contamination from biofuel spills.

    PubMed

    Chen, Colin S; Shu, Youn-Yuen; Wu, Suh-Huey; Tien, Chien-Jung

    2015-03-01

    Future modifications of fuels should include evaluation of the proposed constituents for their potential to damage environmental resources such as the subsurface environment. Batch and column experiments were designed to simulate biofuel spills in the subsurface environment and to evaluate the sorption and desorption behavior of target fuel constituents (i.e., monoaromatic and polyaromatic hydrocarbons) in soil. The extent and reversibility of the sorption of aromatic biofuel constituents onto soil were determined. When the ethanol content in ethanol-blended gasoline exceeded 25%, enhanced desorption of the aromatic constituents to water was observed. However, when biodiesel was added to diesel fuel, the sorption of target compounds was not affected. In addition, when the organic carbon content of the soil was higher, the desorption of target compounds into water was lower. The empirical relationships between the organic-carbon normalized sorption coefficient (Koc) and water solubility and between Koc and the octanol-water partition coefficient (Kow) were established. Column experiments were carried out for the comparison of column effluent concentration/mass from biofuel-contaminated soil. The dissolution of target components depended on chemical properties such as the hydrophobicity and total mass of biofuel. This study provides a basis for predicting the fate and transport of hydrophobic organic compounds in the event of a biofuel spill. The spill scenarios generated can assist in the assessment of biofuel-contaminated sites.

  9. Ex situ bioremediation of oil-contaminated soil.

    PubMed

    Lin, Ta-Chen; Pan, Po-Tsen; Cheng, Sheng-Shung

    2010-04-15

    An innovative bioprocess method, Systematic Environmental Molecular Bioremediation Technology (SEMBT) that combines bioaugmentation and biostimulation with a molecular monitoring microarray biochip, was developed as an integrated bioremediation technology to treat S- and T-series biopiles by using the landfarming operation and reseeding process to enhance the bioremediation efficiency. After 28 days of the bioremediation process, diesel oil (TPH(C10-C28)) and fuel oil (TPH(C10-C40)) were degraded up to approximately 70% and 63% respectively in the S-series biopiles. When the bioaugmentation and biostimulation were applied in the beginning of bioremediation, the microbial concentration increased from approximately 10(5) to 10(6) CFU/g dry soil along with the TPH biodegradation. Analysis of microbial diversity in the contaminated soils by microarray biochips revealed that Acinetobacter sp. and Pseudomonas aeruginosa were the predominant groups in indigenous consortia, while the augmented consortia were Gordonia alkanivorans and Rhodococcus erythropolis in both series of biopiles during bioremediation. Microbial respiration as influenced by the microbial activity reflected directly the active microbial population and indirectly the biodegradation of TPH. Field experimental results showed that the residual TPH concentration in the complex biopile was reduced to less than 500 mg TPH/kg dry soil. The above results demonstrated that the SEMBT technology is a feasible alternative to bioremediate the oil-contaminated soil.

  10. 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.

  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. Implementation of in situ vitrification for contaminated soils

    SciTech Connect

    Luey, J.; Roberts, J.S.; Timmerman, C.L.

    1993-08-01

    Geosafe Corporation will be implementing the in situ vitrification (ISV) technology commercially at a Superfund site in Michigan. In preparation for the Michigan site, Geosafe Corporation performed two operational acceptance tests (OATs) at the Geosafe Test Site in Richland, Washington. The objectives were to test the performance of the equipment and to train operating personnel. In addition, Geosafe cooperated with the Pacific Northwest Laboratory and the US Department of Energy, Office of Technology Development in a full-scale field data collection effort to obtain data characterizing the dynamic conditions in the soil created by the advancing ISV melt. This full-scale information provides empirical data to support the current understanding of the ISV technology for contaminated soil applications and provides verification of the accuracy of computational modeling tools being used to evaluate the applicability of the ISV technology to different soil sites.

  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. Modeling arsenic desorption from herbicide-contaminated soils.

    PubMed

    Qi, Yongqiang; Donahoe, Rona J

    2009-06-01

    The application of arsenical herbicides has created legacy environmental problems by contaminating soil in some agricultural areas and at various industrial sites. Numerous previous studies have suggested that the adsorption of arsenic by common soil components is largely controlled by kinetic factors. Four arsenic-contaminated soil samples collected from industrial sites were characterized and subjected to sequential leaching using a synthetic acid rain solution in order to study the release of arsenic. A dual-site numerical sorption-desorption model was constructed that describes arsenic desorption from these soils in terms of two different release mechanisms: Release from type I (equilibrium) and type II (kinetic) sorption sites. Arsenic held on both type I and II sorption sites is accessible through extensive acid rain leaching. Arsenic desorption from these sites follows a linear Kd model; the manner of approaching the Kd model, however, differs. Arsenic desorption from type I sites reached equilibrium with the aqueous phase under the physical environment provided by the experiment (shaking for 24 h at 25 degrees C), while desorption from type II sites followed a first-order kinetic pattern when approaching equilibrium. During synthetic acid rain sequential leaching of the soils, type I sites released their sorbed arsenic rapidly and subsequent desorption was dominated by the kinetic release of arsenic from type II sites. This shift in desorption mechanism dominance generated data corresponding to two intersecting straight lines in the n-logC dimension for all four soils. The dual-site desorption model was solved analytically and proven to be successful in simulating sorption processes where two different mechanisms are simultaneously controlling the aqueous concentration of a trace element.

  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. 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.

  18. 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.

  19. Effect of soil texture on surfactant-based remediation of hydrophobic organic-contaminated soil.

    PubMed

    Lee, Dal-Heui; Cody, Robert D; Kim, Dong-Ju; Choi, Sangil

    2002-03-01

    Surfactants may be used in remediation of subsoil and aquifer contaminated with hydrophobic compounds. The objectives of this study were to examine the effect of soil texture on hydrophobic organic contaminant (HOC; toluene, or 1,2,4-trichlorobenzene [TCB]) removal from six soils and to evaluate the optimal composition of soil texture for maximum HOC removal using aqueous surfactant solution. Selected surfactants were 4% (vol/vol) sodium diphenyl oxide disulfonate (DOSL) and 4% (wt/vol) sodium lauryl sulfate (LS). Toluene and TCB were selected as the lighter-than-water nonaqueous phase liquid (LNAPL) and denser-than-water nonaqueous phase liquid (DNAPL) model substances, respectively. Soil types used for this study were Ottawa sand and five Iowa soils (Fruitfield, Keomah, Crippin, Webster, and Galvar). The greatest recovery of toluene and TCB in batch tests was 73% and 84%, respectively, which was obtained with DOSL surfactant in Ottawa sand. The toluene removal of 95% in column tests has been achieved in the Ottawa sand and three Iowa soils (Fruitfield, Keomah, Crippin) with DOSL after effluent volume of 3750 ml (about 32 pore volume) passed. TCB removal of 98% in column tests has been achieved in Ottawa sand and three Iowa soils (Fruitfield, Keomah, Crippin) with DOSL after effluent volume of 2500 ml (about 21 pore volume) passed. These results were related with soil texture (clay content 30%), clay mineralogy (kaolinite and smectite), as a function of transported pore volume. PMID:11934118

  20. Effect of soil texture on surfactant-based remediation of hydrophobic organic-contaminated soil.

    PubMed

    Lee, Dal-Heui; Cody, Robert D; Kim, Dong-Ju; Choi, Sangil

    2002-03-01

    Surfactants may be used in remediation of subsoil and aquifer contaminated with hydrophobic compounds. The objectives of this study were to examine the effect of soil texture on hydrophobic organic contaminant (HOC; toluene, or 1,2,4-trichlorobenzene [TCB]) removal from six soils and to evaluate the optimal composition of soil texture for maximum HOC removal using aqueous surfactant solution. Selected surfactants were 4% (vol/vol) sodium diphenyl oxide disulfonate (DOSL) and 4% (wt/vol) sodium lauryl sulfate (LS). Toluene and TCB were selected as the lighter-than-water nonaqueous phase liquid (LNAPL) and denser-than-water nonaqueous phase liquid (DNAPL) model substances, respectively. Soil types used for this study were Ottawa sand and five Iowa soils (Fruitfield, Keomah, Crippin, Webster, and Galvar). The greatest recovery of toluene and TCB in batch tests was 73% and 84%, respectively, which was obtained with DOSL surfactant in Ottawa sand. The toluene removal of 95% in column tests has been achieved in the Ottawa sand and three Iowa soils (Fruitfield, Keomah, Crippin) with DOSL after effluent volume of 3750 ml (about 32 pore volume) passed. TCB removal of 98% in column tests has been achieved in Ottawa sand and three Iowa soils (Fruitfield, Keomah, Crippin) with DOSL after effluent volume of 2500 ml (about 21 pore volume) passed. These results were related with soil texture (clay content 30%), clay mineralogy (kaolinite and smectite), as a function of transported pore volume.

  1. 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

  2. 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.

  3. 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

  4. Innovative treatment of soil contamination: Radiolytic destruction of dioxin and co-contaminants by cobalt-60

    SciTech Connect

    Hilarides, R.J.; Gray, K.A.

    1994-12-31

    Recent work in the laboratory has demonstrated that gamma radiolysis is a feasible method by which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can bee converted to products of negligible toxicity. A standard soil has been artificially contaminated to a level of 100 ppb TCDD and destruction to a level less than 1 ppb has been achieved at a radiation dose of 800 KGy and with the addition of certain soil amendments (water and surfactant). By-product analysis has illustrated that the destruction occurs via step-wise reductive dechlorination and mass balance on carbon has been demonstrated. The presence of co-contaminants at much higher levels does not interfere with TCDD destruction. These results in combination with scavenger studies and target theory calculations indicate that direct radiation effects account for the major route of destruction. Process efficiency has been verified using real contaminated soils and sediments. A reactor design is proposed and an economic analysis is presented to show that radiolysis is technically feasible and economically competitive.

  5. 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.

  6. 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

  7. 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

  8. 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

  9. 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

  10. [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.

  11. 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.

  12. 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.

  13. Efficacy of indigenous soil microbes in arsenic mitigation from contaminated alluvial soil of India.

    PubMed

    Majumder, Aparajita; Bhattacharyya, Kallol; Kole, S C; Ghosh, Sagarmoy

    2013-08-01

    Selected arsenic-volatilizing indigenous soil bacteria were isolated and their ability to form volatile arsenicals from toxic inorganic arsenic was assessed. Approximately 37 % of AsIII (under aerobic conditions) and 30 % AsV (under anaerobic conditions) were volatilized by new bacterial isolates in 3 days. In contrast to genetically modified organism, indigenous soil bacteria was capable of removing 16 % of arsenic from contaminated soil during 60 days incubation period while applied with a low-cost organic nutrient supplement (farm yard manure).

  14. In Situ Depth Profiling of CS-137 Contamination in Soils

    SciTech Connect

    Christopher P. Oertel; John R. Giles; Kenneth C. Thompson; Richard P. Wells

    2004-12-01

    Preremediation characterization of Cs-137 contamination in soils was conducted at the Auxiliary Reactor Area (ARA)-23 Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) site, located at the Idaho National Engineering and Environmental Laboratory. Characterization activities included verification of the lateral extent of the contaminated area using the INEEL Global Positioning Radiometric Scanner. The vertical extent of the contamination in select areas of the site also was evaluated with an in-situ gamma-ray spectrometer, and depth discrete samples were collected at 2-inch depth intervals down to a depth of 8 inches. A comparison was made between the depth distribution data from the in-situ spectrometric measurements and the physical, depth-discrete samples. The results of the study and of the aforementioned comparison indicate that use of in situ high purity germanium (HpGe) detectors during the remediation of the ARA-23 site will aid in directing the depth of excavation, thereby helping to (a) minimize the amount of soils excavated and removed for disposal, and (b) reduce overall project costs.

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. Microwave thermal remediation of crude oil contaminated soil enhanced by carbon fiber.

    PubMed

    Li, Dawei; Zhang, Yaobin; Quan, Xie; Zhao, Yazhi

    2009-01-01

    Thermal remediation of the soil contaminated with crude oil using microwave heating enhanced by carbon fiber (CF) was explored. The contaminated soil was treated with 2.45 GHz microwave, and CF was added to improve the conversion of microwave energy into thermal energy to heat the soil. During microwave heating, the oil contaminant was removed from the soil matrix and recovered by a condensation system of ice-salt bath. The experimental results indicated that CF could efficiently enhance the microwave heating of soil even with relatively low-dose. With 0.1 wt.% CF, the soil could be heated to approximately 700 degrees C within 4 min using 800 W of microwave irradiation. Correspondingly, the contaminated soil could be highly cleaned up in a short time. Investigation of oil recovery showed that, during the remediation process, oil contaminant in the soil could be efficiently recovered without causing significant secondary pollution.

  1. 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

  2. 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...

  3. 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...

  4. Corrective Action Plan for Corrective Action Unit 166: Storage Yards and Contaminated Materials, Nevada Test Site, Nevada

    SciTech Connect

    NSTec Environmental Restoration

    2007-10-01

    Corrective Action Unit (CAU) 166, Storage Yards and Contaminated Materials, is listed in the Federal Facility Agreement and Consent Order (FFACO) of 1996 (FFACO, 1996). CAU 166 consists of seven Corrective Action Sites (CASs) located in Areas 2, 3, 5, and 18 of the Nevada Test Site (NTS), which is located approximately 65 miles northwest of Las Vegas, Nevada (Figure 1). CAU 166 consists of the following CASs: (1) CAS 02-42-01, Cond. Release Storage Yd - North; (2) CAS 02-42-02, Cond. Release Storage Yd - South; (3) CAS 02-99-10, D-38 Storage Area; (4) CAS 03-42-01, Conditional Release Storage Yard; (5) CAS 05-19-02, Contaminated Soil and Drum; (6) CAS 18-01-01, Aboveground Storage Tank; and (7) CAS 18-99-03, Wax Piles/Oil Stain. Details of the site history and site characterization results for CAU 166 are provided in the approved Corrective Action Investigation Plan (CAIP) (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2006) and in the approved Corrective Action Decision Document (CADD) (NNSA/NSO, 2007).

  5. [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.

  6. Quality of trace element contaminated soils amended with compost under fast growing tree Paulownia fortunei plantation.

    PubMed

    Madejón, P; Xiong, J; Cabrera, F; Madejón, E

    2014-11-01

    The use of fast growing trees could be an alternative in trace element contaminated soils to stabilize these elements and improve soil quality. In this study we investigate the effect of Paulownia fortunei growth on trace element contaminated soils amended with two organic composts under semi-field conditions for a period of 18 months. The experiment was carried out in containers filled with tree different soils, two contaminated soils (neutral AZ and acid V) and a non contaminated soil, NC. Three treatments per soil were established: two organic amendments (alperujo compost, AC, and biosolid compost, BC) and a control without amendment addition. We study parameters related with fertility and contamination in soils and plants. Paulownia growth and amendments increased pH in acid soils whereas no effect of these factors was observed in neutral soils. The plant and the amendments also increased organic matter and consequently, soil fertility. Positive results were also found in soils that were only affected by plant growth (without amendment). A general improvement of "soil biochemical quality" was detected over time and treatments, confirming the positive effect of amendments plus paulownia. Even in contaminated soils, except for Cu and Zn, trace element concentrations in leaves were in the normal range for plants. Results of this mid-term study showed that Paulownia fortunei is a promising species for phytoremediation of trace element polluted soils. PMID:24950211

  7. Quality of trace element contaminated soils amended with compost under fast growing tree Paulownia fortunei plantation.

    PubMed

    Madejón, P; Xiong, J; Cabrera, F; Madejón, E

    2014-11-01

    The use of fast growing trees could be an alternative in trace element contaminated soils to stabilize these elements and improve soil quality. In this study we investigate the effect of Paulownia fortunei growth on trace element contaminated soils amended with two organic composts under semi-field conditions for a period of 18 months. The experiment was carried out in containers filled with tree different soils, two contaminated soils (neutral AZ and acid V) and a non contaminated soil, NC. Three treatments per soil were established: two organic amendments (alperujo compost, AC, and biosolid compost, BC) and a control without amendment addition. We study parameters related with fertility and contamination in soils and plants. Paulownia growth and amendments increased pH in acid soils whereas no effect of these factors was observed in neutral soils. The plant and the amendments also increased organic matter and consequently, soil fertility. Positive results were also found in soils that were only affected by plant growth (without amendment). A general improvement of "soil biochemical quality" was detected over time and treatments, confirming the positive effect of amendments plus paulownia. Even in contaminated soils, except for Cu and Zn, trace element concentrations in leaves were in the normal range for plants. Results of this mid-term study showed that Paulownia fortunei is a promising species for phytoremediation of trace element polluted soils.

  8. Influence of brown coal on limit of phytotoxicity of soils contaminated with heavy metals.

    PubMed

    Pusz, A

    2007-11-19

    The paper gives knowledge and application values in efficiency of applying brown coal to limit uptake of heavy metals from contaminated soils by different plant species. The paper determines possibility and principles of using brown coal in reclamation of soils contaminated with heavy metals and rebuilding soils on devastated terrains like terrain in the influence zone of Copper-Smelter "Legnica". On the basis of pot experiment it was stated that increasing doses of brown coal limited phytotoxicity of soils. Results of the paper show that tested fertilizer could be applied on soils strongly contaminated with heavy metals giving long-lasting improvement of reclaimed soils. PMID:17693020

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Using Iron to Treat Chlorohydrocarbon-Contaminated Soil

    NASA Technical Reports Server (NTRS)

    Hitchens, G. Duncan; Hodko, Dalibor; Kim, Heekyung; Rogers, Tom; Singh, Waheguru Pal; Giletto, Anthony; Cisar, Alan

    2004-01-01

    A method of in situ remediation of soil contaminated with chlorinated hydrocarbon solvents involves injection of nanometer-size iron particles. The present method exploits a combination of prompt chemical remediation followed by longer-term enhanced bioremediation and, optionally, is practiced in conjunction with the method of bioremediation described earlier. Newly injected iron particles chemically reduce chlorinated hydrocarbons upon contact. Thereafter, in the presence of groundwater, the particles slowly corrode via chemical reactions that effect sustained release of dissolved hydrogen. The hydrogen serves as an electron donor, increasing the metabolic activity of the anaerobic bacteria and thereby sustaining bioremediation at a rate higher than the natural rate.

  15. Biochemical remediation of a TNT contaminated soil. Doctoral thesis

    SciTech Connect

    Young, D.G.

    1995-06-01

    This research presents the first field evidence for the phytoremediation of a TNT contaminated soil by the emersed aquatic plant, Myriophyllum brasiliense. Commonly known as Parrotfeather, this plant features a nitroreductase enzyme capable of promoting the reduction of the nitro groups on TNT to the corresponding amino groups. The proposed reductive pathway takes the TNT through isomers of monoamino and diamino to the final triaminonitrotoluene (TNT) Once in the TAT form and in the presence of oxygen, the final oxidative step quickly yields ring opened products and complete phytoremediation of TNT.

  16. TXRF analysis of soils and sediments to assess environmental contamination.

    PubMed

    Bilo, Fabjola; Borgese, Laura; Cazzago, Davide; Zacco, Annalisa; Bontempi, Elza; Guarneri, Rita; Bernardello, Marco; Attuati, Silvia; Lazo, Pranvera; Depero, Laura E

    2014-12-01

    Total reflection x-ray fluorescence spectroscopy (TXRF) is proposed for the elemental chemical analysis of crustal environmental samples, such as sediments and soils. A comparative study of TXRF with respect to flame atomic absorption spectroscopy and inductively coupled plasma optical emission spectroscopy was performed. Microwave acid digestion and suspension preparation methods are evaluated. A good agreement was found among the results obtained with different spectroscopic techniques and sample preparation methods for Cr, Mn, Fe, Ni, Cu, and Zn. We demonstrated that TXRF is suitable for the assessment of environmental contamination phenomena, even if the errors for Pb, As, V, and Ba are ingent.

  17. Uranium-contaminated soils: Ultramicrotomy and electron beam analysis

    SciTech Connect

    Buck, E.C.; Dietz, N.L.; Bates, J.K.; Cunnane, J.C.

    1994-04-01

    Uranium contaminated soils from the Fernald Operation Site, Ohio, have been examined by a combination of optical microscopy, scanning electron microscopy with backscattered electron detection (SEM/BSE), and analytical electron microscopy (AEM). A method is described for preparing of transmission electron microscopy (TEM) thin sections by ultramicrotomy. By using these thin sections, SEM and TEM images can be compared directly. Uranium was found in iron oxides, silicates (soddyite), phosphates (autunites), and fluorite. Little uranium was associated with clays. The distribution of uranium phases was found to be inhomogeneous at the microscopic level.

  18. Optimization of contaminant removal for heterogeneous systems by soil venting

    SciTech Connect

    Walton, J.C.; Casey, D.; Anker, C.; LeMone, D.

    1996-12-31

    The efficiency of remediation of vadose zone organic compounds can be enhanced by refinement of methods for soil venting and bioventing in complex heterogeneous systems. This can be accomplished by (a) identification of physical and chemical conditions (e.g., soil temperature, moisture content, flow rates) required for rapid contaminant removal rates, (b) precise engineering control of identified parameters in the subsurface, and (c) development of knowledge-based operational strategies providing greater removal efficiencies at low cost. One method with promise is to moderately heat and humidify the input/replacement air during venting. Initial calculations indicate that this strategy may be quite effective in enhancing remediation of heterogeneous systems with diffusional control of cleanup time.

  19. Chemically enhanced phytoextraction of lead-contaminated soils.

    PubMed

    Perry, V Ryan; Krogstad, Eirik J; El-Mayas, Hanan; Greipsson, Sigurdur

    2012-08-01

    The effects of the combined application of soil fungicide (benomyl) and ethylenediaminetetraacetic acid (EDTA) on lead (Pb) phytoextraction by ryegrass (Lolium perenne) were examined. Twenty-five pots of Pb-contaminated soil (200 mg Pb kg(-1)) were seeded with ryegrass and randomly arranged into the following treatments: (1) Control, (2) benomyl, (3) EDTA, (4) benomyl and EDTA (B+E), and (5) benomyl followed by an application of EDTA 14 days later (B .. . E). Chemicals were applied when plants had reached maximum growth. Plants were analyzed for foliage Pb concentration using inductively coupled argon plasma (ICAP) spectrometry. The synergistic effects of the combined benomyl and EDTA application (treatments 4 and 5) were made evident by the significantly (p < 0.05) highest foliage Pb concentrations. However, the foliage dry biomass was significantly lowest for plants in treatments 4 and 5. The bioaccumulation factor (BF) and phytoextraction ratio (PR) were highest for plants in treatment 5 followed by plants in treatment 4.

  20. Assessing microbial activities in metal contaminated agricultural volcanic soils--An integrative approach.

    PubMed

    Parelho, C; Rodrigues, A S; Barreto, M C; Ferreira, N G C; Garcia, P

    2016-07-01

    Volcanic soils are unique naturally fertile resources, extensively used for agricultural purposes and with particular physicochemical properties that may result in accumulation of toxic substances, such as trace metals. Trace metal contaminated soils have significant effects on soil microbial activities and hence on soil quality. The aim of this study is to determine the soil microbial responses to metal contamination in volcanic soils under different agricultural land use practices (conventional, traditional and organic), based on a three-tier approach: Tier 1 - assess soil microbial activities, Tier 2 - link the microbial activity to soil trace metal contamination and, Tier 3 - integrate the microbial activity in an effect-based soil index (Integrative Biological Response) to score soil health status in metal contaminated agricultural soils. Our results showed that microbial biomass C levels and soil enzymes activities were decreased in all agricultural soils. Dehydrogenase and β-glucosidase activities, soil basal respiration and microbial biomass C were the most sensitive responses to trace metal soil contamination. The Integrative Biological Response value indicated that soil health was ranked as: organic>traditional>conventional, highlighting the importance of integrative biomarker-based strategies for the development of the trace metal "footprint" in Andosols. PMID:27057992

  1. Modification of soil microbial activity and several hydrolases in a forest soil artificially contaminated with copper

    NASA Astrophysics Data System (ADS)

    Bellas, Rosa; Leirós, Mā Carmen; Gil-Sotres, Fernando; Trasar-Cepeda, Carmen

    2010-05-01

    Soils have long been exposed to the adverse effects of human activities, which negatively affect soil biological activity. As a result of their functions and ubiquitous presence microorganisms can serve as environmental indicators of soil pollution. Some features of soil microorganisms, such as the microbial biomass size, respiration rate, and enzyme activity are often used as bioindicators of the ecotoxicity of heavy metals. Although copper is essential for microorganisms, excessive concentrations have a negative influence on processes mediated by microorganisms. In this study we measured the response of some microbial indicators to Cu pollution in a forest soil, with the aim of evaluating their potential for predicting Cu contamination. Samples of an Ah horizon from a forest soil under oakwood vegetation (Quercus robur L.) were contaminated in the laboratory with copper added at different doses (0, 120, 360, 1080 and 3240 mg kg-1) as CuCl2×2H2O. The soil samples were kept for 7 days at 25 °C and at a moisture content corresponding to the water holding capacity, and thereafter were analysed for carbon and nitrogen mineralization capacity, microbial biomass C, seed germination and root elongation tests, and for urease, phosphomonoesterase, catalase and ß-glucosidase activities. In addition, carbon mineralization kinetics were studied, by plotting the log of residual C against incubation time, and the metabolic coefficient, qCO2, was estimated. Both organic carbon and nitrogen mineralization were lower in polluted samples, with the greatest decrease observed in the sample contaminated with 1080 mg kg-1. In all samples carbon mineralization followed first order kinetics; the C mineralization constant was lower in contaminated than in uncontaminated samples and, in general, decreased with increasing doses of copper. Moreover, it appears that copper contamination not only reduced the N mineralization capacity, but also modified the N mineralization process, since in

  2. [Study on composite stabilization of arsenic (As) contaminated soil].

    PubMed

    Wang, Hao; Pan, Li-xiang; Zhang, Xiang-yu; Li, Meng; Song, Bao-hua

    2013-09-01

    Since the contaminated soil may contain various kinds of heavy metals, use of single chemical reagent leads to poor remediation and high cost. In this study, soil containing As, Zn, Cd was sampled, and different reagents were selected to carry out the rapid stabilization of contaminated soil. The TCLP (toxicity characteristic leaching procedure) was used to evaluate the leachate toxicity of heavy metals and the results indicated that calcium-containing, sulphur-containing and iron-containing reagents had good performance in reducing the metal mobility. The stabilization efficiency of the six reagents tested ranked in the order of CaO > Na2S > organic sulfur > Chitosan > FeSO4 > (C2H5)2NCS2Na. Two types of reagents (six reagents) were combined based on the target properties of different reagents and the stabilization efficiency was evaluated and analyzed. The results indicated that the composite reagents had higher stabilization efficiency: the efficiency of 3% FeSO4 + 5% CaO was 81.7%, 97.2% and 68.2% for As, Cd and Zn, respectively, and the efficiency of 3% CaO + 5% organic sulfur was 76.6%, 95.7% and 93.8% for these three metals, respectively. Speciation analysis was carried out in this study and the results suggested that it was the change of metals from the exchangeable state to the reduction (for inorganic reagent) or oxidation state (for organic reagent) that caused the soil stabilization and the degree of change determined the stabilization efficiency. PMID:24289009

  3. Weeds ability to phytoremediate cadmium-contaminated soil.

    PubMed

    Hammami, Hossein; Parsa, Mehdi; Mohassel, Mohammad Hassan Rashed; Rahimi, Salman; Mijani, Sajad

    2016-01-01

    An alternative method to other technologies to clean up the soil, air and water pollution by heavy metals is phytoremediation. Therefore, a pot culture experiment was conducted at the College of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran, in 2014 to determine the potential absorption of cadmium by Portulaca oleracea (Common purslane), Solanum nigrum (Black nightshade), Abutilon theophrasti (Velvetleaf) and Taraxacum officinale (Dandelion). The type of experiment was completely randomized design with factorial arrangement and four replications. The soil in pot was treated with different rates of CdCl2.H2O (0 (control), 10, 20, 40, 60, and 80 mg Cd/kg soil) and the plants were sown. With increasing concentration levels, fresh weight and dry weight of shoots and roots of all plant species were reduced. The reduction severity was ranked according the following order, P. oleracea > A. theophrasti > S. nigrum > T. officinale. Bioconcentration factor (BCF), Translocation factor (TF) and Translocation efficiency (TE%) was ranked according the following order, T. officinale > S. nigrum > A. theophrasti > P. oleracea. The results of this study revealed that T. officinale and S. nigrum are effective species to phytoremediate Cd-contaminated soil. PMID:26125671

  4. Remediation of Cu-contaminated soil using chelant and EAOP.

    PubMed

    Pociecha, Maja; Sircelj, Helena; Lestan, Domen

    2009-09-01

    An electrochemical advanced oxidation process (EAOP) was used for treatment of the washing solution obtained during leaching of Cu (364 +/- 2 mg kg(-1)) contaminated soil, with chelant S,S isomer of ethylenediamine disuccinate ([S,S]-EDDS). In the EAOP (constant current density 40 mA cm(-2)), a boron-doped diamond anode was used for the generation of hydroxyl radicals and oxidative decomposition of [S,S]-EDDS-metal complexes in the washing solution. The released Cu was mostly electro-deposited on the stainless-steel cathode. Three consecutive additions of 5 mmol kg(-1) [S,S]-EDDS removed 46% of the Cu from the soil, mostly from carbonate and oxide soil fractions (87 and 99% Cu reduction). The soil Cu oral availability in the simulated stomach and intestinal phases (in vitro physiologically based extraction test) was reduced by 5.5 and 4.6-times. Cu plant availability (in vitro diethylenetriamine pentaacetate test) was reduced by 3.6-times. The discharge solution was clear, almost colorless, with pH 8.4, 0.45 mg L(-1) Cu and 0.01 mM EDDS. PMID:19847704

  5. Bioremediation treatment of hydrocarbon-contaminated Arctic soils: influencing parameters.

    PubMed

    Naseri, Masoud; Barabadi, Abbas; Barabady, Javad

    2014-10-01

    The Arctic environment is very vulnerable and sensitive to hydrocarbon pollutants. Soil bioremediation is attracting interest as a promising and cost-effective clean-up and soil decontamination technology in the Arctic regions. However, remoteness, lack of appropriate infrastructure, the harsh climatic conditions in the Arctic and some physical and chemical properties of Arctic soils may reduce the performance and limit the application of this technology. Therefore, understanding the weaknesses and bottlenecks in the treatment plans, identifying their associated hazards, and providing precautionary measures are essential to improve the overall efficiency and performance of a bioremediation strategy. The aim of this paper is to review the bioremediation techniques and strategies using microorganisms for treatment of hydrocarbon-contaminated Arctic soils. It takes account of Arctic operational conditions and discusses the factors influencing the performance of a bioremediation treatment plan. Preliminary hazard analysis is used as a technique to identify and assess the hazards that threaten the reliability and maintainability of a bioremediation treatment technology. Some key parameters with regard to the feasibility of the suggested preventive/corrective measures are described as well.

  6. Physical properties of soils contaminated by oil lakes, Kuwait

    SciTech Connect

    Mohammad, A.S.; Wahba, S.A.; Al-Khatieb, S.O.

    1996-08-01

    In preparation for a marine assault by the coalition forces, the Iraqi Army heavily mined Kuwait`s coastal zone and the oil fields. Over a million mines were placed on the Kuwait soil. Burning of 732 oil wells in the State of Kuwait due to the Iraqi invasion caused damages which had direct and indirect effect on environment. A total of 20-22 million barrels of spilled crude oil were collected in natural desert depressions and drainage network which formed more than 300 oil lakes. The total area covered with oil reached 49 km{sup 2}. More than 375 trenches revealed the existence of hard, massive caliche (CaCO{sub 3}) subsoil which prevent leached oil from reaching deeper horizons, and limited the maximum depth of penetration to 1.75 m. Total volume of soil contaminated reached 22,652,500 m{sup 3} is still causing environmental problems and needs an urgent cleaning and rehabilitation. Kuwait Oil Company has recovered approximately 21 million barrels from the oil lakes since the liberation of Kuwait. In our examined representative soil profiles the oil penetration was not deeper than 45 cm. Infiltration rate, soil permeability, grain size distribution, aggregates formation and water holding capacity were assessed. 15 refs., 5 figs., 5 tabs.

  7. Chromium and arsenic in contaminated soils (Review of publications)

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.

    2009-05-01

    In the last decades, the chromium clarke in the world’s soils has been revised and reduced; at present, it is equal to 70 mg/kg. No maximal permissible concentration is accepted for the total chromium content in the soils of Russia; it appears reasonable to use the Western European and North American standards in Russia and to take the average value of the maximal permissible concentration equal to 200 mg Cr/kg. Chromium toxicity depends on its oxidizing status. The hazardous effect decreases with the reduction of Cr(VI) to Cr(III). There are various chemical reducers of Cr(VI), including sulfides, dissolved organic substance, aqueous Fe(II) and minerals enriched in Fe(II), and Fe(0). As-containing ore tailings represent a powerful source of technogenic arsenic. Significant environment contamination with natural As is registered in a number of Asian countries. The maximal permissible concentration of total arsenic is equal to 2 mg/kg in Russian soils; it is probably underestimated, because it is lower than the As clarke in soil (5 mg/kg). The approximately permissible concentration (APC) values for As look more reasonable. Arsenic toxicity depends on its oxidation degree: As(III) is 2-3 times more toxic than As(V).

  8. Plumbum contamination detecting model for agricultural soil using hyperspectral data

    NASA Astrophysics Data System (ADS)

    Liu, Xiangnan; Huang, Fang; Wang, Ping

    2008-10-01

    The issue of environmental pollution due to toxic heavy metals in agricultural land has caused worldwide growing concern in recent years. Being one of toxic heavy metals, the accumulation of Plumbum (Pb) may have negative effects on natural and agricultural vegetation growth, yield and quality. It can also constitute short-term and long-term health risks by entering the food chain. In this study, we analyze the relationships between physical and chemical characteristics, biological parameters of soil-vegetation system and hyperspectral spectrum responses systematically. The relation between hyperspectral data and the biological parameters of Pb polluted wheat canopy such as leaf pigments, leaf moisture, cell structure and leaf area index (LAI) are discussed. We detect the changes in the wheat biological parameters and spectral response associated with Pb concentration in soil. To reveal the impact mechanisms of Pb concentration on agricultural soil, six models including chlorophyll-leaf moisture model, chlorophyll-cell structure model, chlorophyll-LAI model, leaf moisture-cell structure model, leaf moisture-LAI model, cell structure- LAI model are explored. We find that changes in Pb concentration present various features in different models. Pb contamination in agricultural soil can be identified and assessed effectively while integrating the characteristics of those developed models.

  9. Weeds ability to phytoremediate cadmium-contaminated soil.

    PubMed

    Hammami, Hossein; Parsa, Mehdi; Mohassel, Mohammad Hassan Rashed; Rahimi, Salman; Mijani, Sajad

    2016-01-01

    An alternative method to other technologies to clean up the soil, air and water pollution by heavy metals is phytoremediation. Therefore, a pot culture experiment was conducted at the College of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran, in 2014 to determine the potential absorption of cadmium by Portulaca oleracea (Common purslane), Solanum nigrum (Black nightshade), Abutilon theophrasti (Velvetleaf) and Taraxacum officinale (Dandelion). The type of experiment was completely randomized design with factorial arrangement and four replications. The soil in pot was treated with different rates of CdCl2.H2O (0 (control), 10, 20, 40, 60, and 80 mg Cd/kg soil) and the plants were sown. With increasing concentration levels, fresh weight and dry weight of shoots and roots of all plant species were reduced. The reduction severity was ranked according the following order, P. oleracea > A. theophrasti > S. nigrum > T. officinale. Bioconcentration factor (BCF), Translocation factor (TF) and Translocation efficiency (TE%) was ranked according the following order, T. officinale > S. nigrum > A. theophrasti > P. oleracea. The results of this study revealed that T. officinale and S. nigrum are effective species to phytoremediate Cd-contaminated soil.

  10. Degradation of alkyllead compounds to inorganic lead in contaminated soil.

    PubMed

    Gallert, C; Winter, J

    2004-11-01

    In glass columns with sandy soil from a former antiknocking agents factory hydrophobic tetraalkyllead was transformed in oxygen-saturated water to inorganic lead. Up to 324 mg l(-1) trialkyllead, but only very little dialkyllead accumulated. After 740 days 49.1+/-6.7% of the organic lead was converted to inorganic lead. Conversion of hydrocarbons was 39.6+/-5.1%. To reduce toxicity of high trialkyllead concentrations the water of soil columns was replaced by tap water after 450d. Trialkyllead in the new water increased again to more than 150 mg l(-1). If the alkyllead-containing water from these columns was diluted to concentrations of alkyllead compounds that were found in the groundwater after air injection (total alkyllead<10 mg l(-1)) and used as a source of alkyllead compounds in columns with non-contaminated sandy soil, elimination of tetra-, tri- and dialkyllead compounds followed first-order kinetics. In the soil 85.8-93.6% of the alkyllead dissappeared in only 170 days with 51% being converted to inorganic lead. This makes in situ remediation reasonable.

  11. Thermal treatment of soils contaminated with gas oil: influence of soil composition and treatment temperature.

    PubMed

    Piña, Juliana; Merino, Jerónimo; Errazu, Alberto F; Bucalá, Verónica

    2002-10-14

    Samples of two soils containing different organic matter contents, neat or contaminated with gas oil (diesel fuel oil) at 2.5 wt.% were heated from room temperature to different final temperatures (200-900 degrees C). The experiments, performed in an anaerobic media, simulate conditions pertinent to ex situ thermal desorptive and thermal destructive treatments. The products generated during the heating were collected and light gases were analyzed by gas chromatography. The results indicate that the chemical composition of the soil is a key factor since it strongly influences the quantity and composition of the off-gases. According to the liquid and light gas yields, the gas oil does not affect appreciably the generation of pyrolysis products of the own soil constituents and the gas oil does not suffer significant chemical transformations even at high operating temperatures (e.g. 900 degrees C). With surface areas of 16000 cm(2)/g (Soil A) and 85000 cm(2)/g (Soil B) based on the monolayer adsorbed model, 4 and 20%, respectively, of the original gas oil can be adsorbed. These values are in good agreement with experimental data. Even for high temperatures, the employed thermal treatment is capable to practically remove the gas oil from the soil bed without changing appreciably the original chemical composition of the contaminant.

  12. Remediation of Cr(VI)-Contaminated Soil Using the Acidified Hydrazine Hydrate.

    PubMed

    Ma, Yameng; Li, Fangfang; Jiang, Yuling; Yang, Weihua; Lv, Lv; Xue, Haotian; Wang, Yangyang

    2016-09-01

    Acidified hydrazine hydrate was used to remediate Cr(VI)-contaminated soil. The content of water-soluble Cr(VI) in contaminated soil was 4977.53 mg/kg. The optimal initial pH of hydrazine hydrate solution, soil to solution ratio and molar ratio of Cr(VI) to hydrazine hydrate for remediation of Cr(VI)-contaminated soil were 5.0, 3:1 and 1:3, respectively. Over 99.50 % of water-soluble Cr(VI) in the contaminated soil was reduced at the optimal condition within 30 min. The remediated soil can keep stable within 4 months. Meanwhile the total phosphorus increased from 0.47 to 4.29 g/kg, indicating that using of acidified hydrazine hydrate is an effective method to remediate Cr(VI)-contaminated soil.

  13. Remediation of Cr(VI)-Contaminated Soil Using the Acidified Hydrazine Hydrate.

    PubMed

    Ma, Yameng; Li, Fangfang; Jiang, Yuling; Yang, Weihua; Lv, Lv; Xue, Haotian; Wang, Yangyang

    2016-09-01

    Acidified hydrazine hydrate was used to remediate Cr(VI)-contaminated soil. The content of water-soluble Cr(VI) in contaminated soil was 4977.53 mg/kg. The optimal initial pH of hydrazine hydrate solution, soil to solution ratio and molar ratio of Cr(VI) to hydrazine hydrate for remediation of Cr(VI)-contaminated soil were 5.0, 3:1 and 1:3, respectively. Over 99.50 % of water-soluble Cr(VI) in the contaminated soil was reduced at the optimal condition within 30 min. The remediated soil can keep stable within 4 months. Meanwhile the total phosphorus increased from 0.47 to 4.29 g/kg, indicating that using of acidified hydrazine hydrate is an effective method to remediate Cr(VI)-contaminated soil. PMID:27351195

  14. Germination and initial growth of Campomanesia xanthocarpa O. Berg. (Myrtaceae), in petroleum-contaminated soil and bioremediated soil.

    PubMed

    Gogosz, A M; Bona, C; Santos, G O; Botosso, P C

    2010-11-01

    In 2000 there was an oil spill at the Getúlio Vargas Refinery (REPAR) in Paraná. Nearly five years after contamination and the use of bioremediation, a study was carried out to identify the effects of the contaminated soil and the bioremediated soil on the germination and initial growth of C. xanthocarpa. The experiment was established with soil from REPAR, with three treatment groups: contaminated soil (C), bioremediated soil (B) and uncontaminated soil (U); with five repetitions of 50 seeds each. There was no significant difference in the percentage of germination and the speed of germination index. The production of total biomass (30 - 60 days) and shoot biomass (60 days) was greater in the bioremediated soil compared to the other treatments. The averages for the root biomass were lower in the contaminated soil than in the bioremediated soil. The shoot length and the total length of the seedling in the contaminated soil and uncontaminated soil were lower than in the bioremediated soil.

  15. Stabilization and solidification of chromium-contaminated soil

    SciTech Connect

    Cherne, C.A.; Thomson, B.M.; Conway, R.

    1997-11-01

    Chromium-contaminated soil is a common environmental problem in the United States as a result of numerous industrial processes involving chromium. Hexavalent chromium [Cr(VI)] is the species of most concern because of its toxicity and mobility in groundwater. One method of diminishing the environmental impact of chromium is to reduce it to a trivalent oxidation state [Cr(III)], in which it is relatively insoluble and nontoxic. This study investigated a stabilization and solidification process to minimize the chromium concentration in the Toxicity Characteristic Leaching Procedure (TCLP) extract and to produce a solidified waste form with a compressive strength in the range of 150 to 300 pounds per square inch (psi). To minimize the chromium in the TCLP extract, the chromium had to be reduced to the trivalent oxidation state. The average used in this study was an alluvium contaminated with chromic and sulfuric acid solutions. The chromium concentration in the in the in situ soil was 1212 milligrams per kilogram (mg/kg) total chromium and 275 mg/kg Cr(VI). The effectiveness of iron, ferrous sulfate to reduce Cr(VI) was tested in batch experiments.

  16. Chemometric assessment of enhanced bioremediation of oil contaminated soils.

    PubMed

    Soleimani, Mohsen; Farhoudi, Majid; Christensen, Jan H

    2013-06-15

    Bioremediation is a promising technique for reclamation of oil polluted soils. In this study, six methods for enhancing bioremediation were tested on oil contaminated soils from three refinery areas in Iran (Isfahan, Arak, and Tehran). The methods included bacterial enrichment, planting, and addition of nitrogen and phosphorous, molasses, hydrogen peroxide, and a surfactant (Tween 80). Total petroleum hydrocarbon (TPH) concentrations and CHEMometric analysis of Selected Ion Chromatograms (SIC) termed CHEMSIC method of petroleum biomarkers including terpanes, regular, diaromatic and triaromatic steranes were used for determining the level and type of hydrocarbon contamination. The same methods were used to study oil weathering of 2 to 6 ring polycyclic aromatic compounds (PACs). Results demonstrated that bacterial enrichment and addition of nutrients were most efficient with 50% to 62% removal of TPH. Furthermore, the CHEMSIC results demonstrated that the bacterial enrichment was more efficient in degradation of n-alkanes and low molecular weight PACs as well as alkylated PACs (e.g. C₃-C₄ naphthalenes, C₂ phenanthrenes and C₂-C₃ dibenzothiophenes), while nutrient addition led to a larger relative removal of isoprenoids (e.g. norpristane, pristane and phytane). It is concluded that the CHEMSIC method is a valuable tool for assessing bioremediation efficiency.

  17. Relative Bioavailability and Bioaccessability and Speciation of Arsenic in Contaminated Soils

    EPA Science Inventory

    Background: Assessment of soil arsenic (As) bioavailability may profoundly affect the extent of remediation required at contaminated sites by improving human exposure estimates. Because small adjustments in soil As bioavailability estimates can significantly alter risk assessment...

  18. 40 CFR 267.116 - What must I do with contaminated equipment, structure, and soils?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... that waste following all applicable requirements of 40 CFR part 262. ... equipment, structure, and soils? 267.116 Section 267.116 Protection of Environment ENVIRONMENTAL PROTECTION..., structure, and soils? You must properly dispose of or decontaminate all contaminated equipment,...

  19. 40 CFR 267.116 - What must I do with contaminated equipment, structure, and soils?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... that waste following all applicable requirements of 40 CFR part 262. ... equipment, structure, and soils? 267.116 Section 267.116 Protection of Environment ENVIRONMENTAL PROTECTION..., structure, and soils? You must properly dispose of or decontaminate all contaminated equipment,...

  20. 40 CFR 267.116 - What must I do with contaminated equipment, structure, and soils?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... that waste following all applicable requirements of 40 CFR part 262. ... equipment, structure, and soils? 267.116 Section 267.116 Protection of Environment ENVIRONMENTAL PROTECTION..., structure, and soils? You must properly dispose of or decontaminate all contaminated equipment,...

  1. 40 CFR 267.116 - What must I do with contaminated equipment, structure, and soils?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... that waste following all applicable requirements of 40 CFR part 262. ... equipment, structure, and soils? 267.116 Section 267.116 Protection of Environment ENVIRONMENTAL PROTECTION..., structure, and soils? You must properly dispose of or decontaminate all contaminated equipment,...

  2. 40 CFR 267.116 - What must I do with contaminated equipment, structure, and soils?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... that waste following all applicable requirements of 40 CFR part 262. ... equipment, structure, and soils? 267.116 Section 267.116 Protection of Environment ENVIRONMENTAL PROTECTION..., structure, and soils? You must properly dispose of or decontaminate all contaminated equipment,...

  3. Legacy soil contamination at abandoned mine sites: making a case for guidance on soil protection.

    PubMed

    Kostarelos, Konstantinos; Gavriel, Ifigenia; Stylianou, Marinos; Zissimos, Andreas M; Morisseau, Eleni; Dermatas, Dimitris

    2015-03-01

    Within the European Union, guidance in the form of a uniform Soil Directive does not exist and member states are left to enact their own legislation governing historic soil contamination. Several historic or "legacy" sites exist in Cyprus - an EU member state with a long history of mining and a significant number of abandoned mining sites. The gold-silver enrichment plant of Mitsero village was abandoned 70 years ago, yet soil samples inside and outside the plant were extremely low in pH, exhibited high leachability of heavy metals and high cyanide levels. Water samples collected from an ephemeral stream located down-gradient of the site contained high levels of heavy metals. Two abandoned open-pit mines (Kokkinopezoula and Mathiatis) were investigated, where elevated metal content in soil samples from the surrounding streams and spoil heaps, and extremely low pH and high metal content in water samples from the mine crater were measured. PMID:25600021

  4. Effect of OSE(II)-Enhanced Soil Washing(OESW) for TPH -Contaminated Soil Remediation

    NASA Astrophysics Data System (ADS)

    Hwang, J. H.; Lee, D. H.; Woo, N. C.

    2015-12-01

    The objectives of this study were to perform potentially suitable active agent that solubilize total petroleum hydrocarbon (TPH) present as contaminants and to evaluate the optimal range of process parameters that can increase the removal efficiency in OSE(II)-enhanced soil washing (OESW) pilot tests. Used experimental method for solubilisation of TPH by using OSE(II) was batch experiments. The active agent solution parameters for OESW pilot tests were solution concentration, solution pH in the OESW pilot tests. Based on the batch experiments, OSE(II) was proved as a suitable active agent that solubilizes TPH present as contaminants. The highest recovery (92-95 %) of the contaminants was obtained using a OSE(II) in the batch experiments. The pilot test results revealed that the optimum conditions were achieved with a OSE(II) surfactant solution concentration of 10 % (v/v), a OSE(II) surfactant solution pH of 6.5-7.5 of OSE(II) active agent solution. The maximum removal of contaminants (88 %) was obtained when optimum conditions were simultaneously met in pilot-scale OESW operations. These results confirm the viability of OESW for treating TPH-contaminated soil.

  5. Bioreduction of uranium in a contaminated soil column.

    PubMed

    Gu, Baohua; Wu, Wei-Min; Ginder-Vogel, Matthew A; Yan, Hui; Fields, Matthew W; Zhou, Jizhong; Fendorf, Scott; Criddle, Craig S; Jardine, Philip M

    2005-07-01

    The bioreduction of soluble uranium [U(VI)] to sparingly soluble U(IV) species is an attractive remedial technology for contaminated soil and groundwater due to the potential for immobilizing uranium and impeding its migration in subsurface environments. This manuscript describes a column study designed to simulate a three-step strategy proposed for the remediation of a heavily contaminated site at the U.S. Department of Energy's NABIR Field Research Center in Oak Ridge, TN. The soil is contaminated with high concentrations of uranium, aluminum, and nitrate and has a low, highly buffered pH (approximately 3.5). Steps proposed for remediation are (i) flushing to remove nitrate and aluminum, (ii) neutralization to establish pH conditions favorable for biostimulation, and (iii) biostimulation for U(VI) reduction. We simulated this sequence using a packed soil column containing undisturbed aggregates of U(VI)-contaminated saprolite that was flushed with an acidified salt solution (pH 4.0), neutralized with bicarbonate (60 mM), and then biostimulated by adding ethanol. The column was operated anaerobically in a closed-loop recirculation setup. However, during the initial month of biostimulation, ethanol was not utilized, and U(VI) was not reduced. A bacterial culture enriched from the site groundwaterwas subsequently added, and the consumption of ethanol coupled with sulfate reduction immediately ensued. The aqueous concentration of U(VI) initially increased, evidently because of the biological production of carbonate, a ligand known to solubilize uranyl. After approximately 50 days, aqueous U(VI) concentrations rapidly decreased from approximately 17 to <1 mg/L. At the conclusion of the experiment,the presence of reduced solid phase U(IV) was confirmed using X-ray absorption near edge structure spectroscopy. The results indicate that bioreduction to immobilize uranium is potentially feasible at this site; however, the stability of the reduced U(IV) and its potential

  6. Repeated phytoextraction of four metal-contaminated soils using the cadmium/zinc hyperaccumulator Sedum plumbizincicola.

    PubMed

    Li, Zhu; Wu, Longhua; Hu, Pengjie; Luo, Yongming; Zhang, Hao; Christie, Peter

    2014-06-01

    A cadmium/zinc hyperaccumulator extracted metals from four contaminated soils over three years in a glasshouse experiment. Changes in plant metal uptake and soil total (aqua regia-extractable) and available metals were investigated. Plant Cd concentrations in a high-Cd acid soil and plant Zn concentrations in two acid soils decreased during repeated phytoextraction and were predicted by soil available metal concentrations. However, on repeated phytoextraction, plant Cd concentrations remained constant in lightly Cd-polluted acid soils, as did plant Cd and Zn in alkaline soils, although soil available metal concentrations decreased markedly. After phytoextraction acid soils showed much higher total metal removal efficiencies, indicating possible suitability of phytoextraction for acid soils. However, DGT-testing, which takes soil metal re-supply into consideration, showed substantial removal of available metal and distinct decreases in metal supply capacity in alkaline soils after phytoextraction, suggesting that a strategy based on lowering the bioavailable contaminant might be feasible. PMID:24675367

  7. Effect of soil type on distribution and bioaccessibility of metal contaminants in shooting range soils.

    PubMed

    Sanderson, Peter; Naidu, Ravi; Bolan, Nanthi; Bowman, Mark; McLure, Stuart

    2012-11-01

    Shooting ranges from Department of Defence sites around Australia were investigated for extent of metal contamination. Shooting range soils contained concentrations ranging from 399 to 10,403 mg/kg Pb, 6.57 to 252 mg/kg Sb, 28.7 to 1250 mg/kg Cu, 5.63 to 153 mg/kg Zn, 1.35 to 8.8 mg/kg Ni and 3.08 to 15.8 mg/kg As. Metal(loid)s were primarily concentrated in the stop butt and the surface soil (0-10 cm). The distribution of contamination reflected firing activity, soil properties, climate and management practices. Climatic variations among sites in Australia are significant, with a temperate climate in the south and tropical climate with high rainfall in the north. Up to 8% of total Pb resided in soil fines (<0.075 mm), due to the fragmentation of bullets on impact. Distribution and bioaccessibility varied between each site. Acidic Townsville soil had the highest proportion of water extractable Pb at 10%, compared to the alkaline Murray Bridge with only 2% Pb water extractable. Soil properties such as CEC, pH and dissolved organic carbon influence mobility. This is reflected in the subsoil concentrations of Pb in Townsville and Darwin which are up to 30 and 46% of surface concentration in the subsoil respectively. Similarly bioaccessibility is influenced by soil properties and ranges from 46% in Townsville to 70% in Perth. Acidic pH promotes dissolution of secondary minerals and the downward movement of Pb in the profile. The secondary Pb minerals formed as a result of weathering in these soils were cerussite, hydrocerussite, pyromorphite, galena and anglesite. Copper oxide was also reported on fragments from bullet jackets. These results have implications for range management. PMID:23026152

  8. 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.

  9. Effect of long-term zinc pollution on soil microbial community resistance to repeated contamination.

    PubMed

    Klimek, Beata

    2012-04-01

    The aim of the study was to compare the effects of stress (contamination trials) on the microorganisms in zinc-polluted soil (5,018 mg Zn kg(-1) soil dry weight) and unpolluted soil (141 mg Zn kg(-1) soil dw), measured as soil respiration rate. In the laboratory, soils were subjected to copper contamination (0, 500, 1,500 and 4,500 mg kg(-1) soil dw), and then a bactericide (oxytetracycline) combined with a fungicide (captan) along with glucose (10 mg g(-1) soil dw each) were added. There was a highly significant effect of soil type, copper treatment and oxytetracycline/captan treatment. The initial respiration rate of chronically zinc-polluted soil was higher than that of unpolluted soil, but in the copper treatment it showed a greater decline. Microorganisms in copper-treated soil were more susceptible to oxytetracycline/captan contamination. After the successive soil contamination trials the decline of soil respiration was greater in zinc-polluted soil than in unpolluted soil.

  10. Thermal desorption of PCBs from contaminated soil with copper dichloride.

    PubMed

    Liu, Jie; Qi, Zhifu; Li, Xiaodong; Chen, Tong; Buekens, Alfons; Yan, Jianhua; Ni, Mingjiang

    2015-12-01

    Copper dichloride is an important catalyst both in the dechlorination of chlorinated aromatic compounds and the formation of PCDD/Fs. The effect of copper dichloride on polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) was studied in treated soil and off gas after thermal desorption of PCB-contaminated soil at 300, 400, 500, 600 °C. The presence of copper dichloride clearly enhances thermal desorption by promoting PCBs removal, destruction, and dechlorination. After thermal treatment at 600 °C for 1 h, the removal efficiency and destruction efficiency for PCBs reached 98.1 and 93.9%, respectively. Compared with the positive influence on PCBs, copper dichloride catalyzed large amount of PCDFs formation at 300 °C, with the concentration ratio of 2.35. The effect of CuCl2 on PCDFs formation weakened with the rising temperature since PCDFs destruction became dominant under higher temperature. Different from PCDFs, PCDDs concentration in treated soil and off gas decreased continuously with the increasing temperature. PMID:26233752

  11. Thermal desorption of PCBs from contaminated soil with copper dichloride.

    PubMed

    Liu, Jie; Qi, Zhifu; Li, Xiaodong; Chen, Tong; Buekens, Alfons; Yan, Jianhua; Ni, Mingjiang

    2015-12-01

    Copper dichloride is an important catalyst both in the dechlorination of chlorinated aromatic compounds and the formation of PCDD/Fs. The effect of copper dichloride on polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) was studied in treated soil and off gas after thermal desorption of PCB-contaminated soil at 300, 400, 500, 600 °C. The presence of copper dichloride clearly enhances thermal desorption by promoting PCBs removal, destruction, and dechlorination. After thermal treatment at 600 °C for 1 h, the removal efficiency and destruction efficiency for PCBs reached 98.1 and 93.9%, respectively. Compared with the positive influence on PCBs, copper dichloride catalyzed large amount of PCDFs formation at 300 °C, with the concentration ratio of 2.35. The effect of CuCl2 on PCDFs formation weakened with the rising temperature since PCDFs destruction became dominant under higher temperature. Different from PCDFs, PCDDs concentration in treated soil and off gas decreased continuously with the increasing temperature.

  12. Potassium permanganate oxidation of phenanthrene and pyrene in contaminated soils.

    PubMed

    de Souza e Silva, Paula Tereza; da Silva, Valdinete Lins; Neto, Benício de Barros; Simonnot, Marie-Odile

    2009-09-15

    Potassium permanganate, widely used in water treatment, has shown its applicability to reduce PAH contamination in groundwater and soils. The first stage to design a treatment at the site scale is the feasibility study at the bench scale, generally performed by means of batch experiments. The aim of the present contribution was to investigate the influence of two factors on PAH degradation in spiked soils, following the method of factorial designs. These factors were the weight ratio KMnO(4)/PAH and the reaction time. Three factorial designs were performed and batch experiments were run to study the degradation of phenanthrene and pyrene on soils spiked at different concentrations, between 700 and 2100 mg kg(-1). We showed that treatment with potassium permanganate significantly reduced PAH concentration, but pyrene was more recalcitrant than phenanthrene. Both variables had negative main effects and a positive two-factor interaction effect: increasing the weight ratio or the reaction time enhanced PAH degradation but the reduction produced by the two factors was lower than the sum of the individual contributions. The comparison of these results with results that we published previously under comparable conditions showed that Fenton's reagent was more efficient than potassium permanganate.

  13. Impact of coal mine dump contaminated soils on elemental uptake by Spinacia oleracea (spinach)

    SciTech Connect

    Chunilall, V.; Kindness, A.; Jonnalagadda, S.B.

    2006-07-01

    The elemental uptake and the growth response of Spinacia oleracea (spinach) to the soil contaminated with the South African bituminous coal mine dump soil, viz. 0%, 5%, 15%, and 25% w/w, was investigated. The contaminated soils were analyzed for pH, cation exchange capacity (CEC), soil organic matter (SOM), and concentrations of selected heavy metals. The pH, SOM, and CEC decreased with an increase in contamination indicating the acidic nature of coal mine soil and the raise in the soil binding sites. The distribution of Fe, Mn, Ni, Cd, and Pb in the roots and leaves of the plants was determined in two stages of plant growth. Spinach showed high accumulation of Fe and increased levels of Ni and Cd with an increase in contamination. No plant growth was recorded with 25% contamination.

  14. Approaches to assessing the risk of chemical contamination of Urban Soils

    NASA Astrophysics Data System (ADS)

    Makarov, O. A.; Makarov, A. A.

    2016-09-01

    The existing approaches to studying the risk of chemical contamination of soils are analyzed. It is noted that the actual and critical loads of contaminants on the soil cover are often compared for estimating these risks. The insufficient use of economic tools and methods for assessing the risk of soil contamination is emphasized. The sanitary-hygienic standards are found out to be exceeded for lead, zinc, cadmium and copper content in soils in six localities, each of 6250 m2 in the area, situated in the industrial and transport zones of Podol'sk and Moscow. The values of actual and maximal permissible damage exerted by the heavy-metal contamination to the studied soils are calculated. The probable damage R and the degree of probable damage implementation (DPDI) are used as the indices of soil contamination risk.

  15. Growth response of Avena sativa in amino-acids-rich soils converted from phenol-contaminated soils by Corynebacterium glutamicum.

    PubMed

    Lee, Soo Youn; Kim, Bit-Na; Choi, Yong Woo; Yoo, Kye Sang; Kim, Yang-Hoon; Min, Jiho

    2012-04-01

    The biodegradation of phenol in laboratory-contaminated soil was investigated using the Gram-positive soil bacterium Corynebacterium glutamicum. This study showed that the phenol degradation caused by C. glutamicum was greatly enhanced by the addition of 1% yeast extract. From the toxicity test using Daphnia magna, the soil did not exhibit any hazardous effects after the phenol was removed using C. glutamicum. Additionally, the treatment of the phenolcontaminated soils with C. glutamicum increased various soil amino acid compositions, such as glycine, threonine, isoleucine, alanine, valine, leucine, tyrosine, and phenylalanine. This phenomenon induced an increase in the seed germination rate and the root elongation of Avena sativa (oat). This probably reflects that increased soil amino acid composition due to C. glutamicum treatment strengthens the plant roots. Therefore, the phenol-contaminated soil was effectively converted through increased soil amino acid composition, and additionally, the phenol in the soil environment was biodegraded by C. glutamicum.

  16. Treatment of Aroclor 1016 contaminated soil by hydrogen peroxide: laboratory column study.

    PubMed

    Viisimaa, Marika; Veressinina, Jelena; Goi, Anna

    2012-09-01

    The potential and feasibility of treating soil contaminated with electrical insulating oil, Aroclor 1016, containing polychlorinated biphenyls (PCBs) with stabilized hydrogen peroxide were evaluated using columns packed with soils of two different matrixes. The column experiments showed that PCBs degraded by the stabilized hydrogen peroxide treatment in both soil matrixes, although the efficacy of the treatment depended strongly on the soil characteristics. The removal of PCB-containing oil was higher in sandy silt soil than in sandy soil. While a higher iron content promoted hydrogen peroxide oxidation of the contaminant in sandy silt soil, lower permeability and higher organic matter content contributed to an oxidation decrease as a function of depth. Dehydrogenase activity measurements indicated no substantial changes in microbial activity during the treatment of both sandy and sandy silt soils, thus offering opportunities to apply the hydrogen peroxide treatment to the remediation of PCB-contaminated soil.

  17. Assessment of sampling strategy for explosives-contaminated soils

    SciTech Connect

    Thiboutot, S.; Ampleman, G.; Jenkins, T.F.; Walsh, M.E.; Thorne, P.G.; Ranney, T.A.; Grant, C.L.

    1997-12-31

    An explosives-contaminated site was characterized using composite sampling, in-field sample homogenization and on-site analysis. Explosives contaminated sites demonstrate large short-range heterogeneity due to the crystalline nature and poor water solubility of the dispersed contaminants. The sampling strategy must be carefully planned in order to minimize sampling error and total uncertainty. The site investigated in this particular study is an anti-tank firing range that has been in-use for over 20 years. The ammunition fired at this range is a melt-cast explosive based on a mixture of HMX and TNT in the ratio of 70:30. Two previous preliminary sampling surveys of this site have shown high levels of HMX in soil samples collected nearby the targeted tanks. This particular site was chosen for a collaborative effort between the Canadian Department of National Defence and the USA Department of Defense to study sampling strategies and sample heterogeneity where HMX is the main contaminant. On-site colorimetric TNT and HMX methods and enzyme immunoassay TNT and RDX methods were used initially to evaluate if the sampling pattern used provided representative results. A 6 m square grid (36 m{sup 2}) pattern was established, including two of the targeted tanks. Seventeen grids were installed and composite samples were collected within those grids. Four surface composite samples were collected in each quadrant of each grid using a circular pattern that sampled about 10% of the top 5 cm of the surface. Replicates were collected to assess the representativeness achieved. Field analysis showed concentrations of HMX ranged from as high as 1640 mg/kg near one target to 2.1 mg/kg at a distance of 15 m from the target. On the other hand, TNT concentrations were much lower than would be expected based on the 70:30 composition ratio. Results from the colorimetric on-site analyses were in excellent agreement with laboratory results.

  18. Quantitative assessment on soil enzyme activities of heavy metal contaminated soils with various soil properties.

    PubMed

    Xian, Yu; Wang, Meie; Chen, Weiping

    2015-11-01

    Soil enzyme activities are greatly influenced by soil properties and could be significant indicators of heavy metal toxicity in soil for bioavailability assessment. Two groups of experiments were conducted to determine the joint effects of heavy metals and soil properties on soil enzyme activities. Results showed that arylsulfatase was the most sensitive soil enzyme and could be used as an indicator to study the enzymatic toxicity of heavy metals under various soil properties. Soil organic matter (SOM) was the dominant factor affecting the activity of arylsulfatase in soil. A quantitative model was derived to predict the changes of arylsulfatase activity with SOM content. When the soil organic matter content was less than the critical point A (1.05% in our study), the arylsulfatase activity dropped rapidly. When the soil organic matter content was greater than the critical point A, the arylsulfatase activity gradually rose to higher levels showing that instead of harm the soil microbial activities were enhanced. The SOM content needs to be over the critical point B (2.42% in our study) to protect its microbial community from harm due to the severe Pb pollution (500mgkg(-1) in our study). The quantitative model revealed the pattern of variation of enzymatic toxicity due to heavy metals under various SOM contents. The applicability of the model under wider soil properties need to be tested. The model however may provide a methodological basis for ecological risk assessment of heavy metals in soil.

  19. Test plan for the soils facility demonstration: A petroleum contaminated soil bioremediation facility

    SciTech Connect

    Lombard, K.H.

    1994-08-01

    The objectives of this test plan are to show the value added by using bioremediation as an effective and environmentally sound method to remediate petroleum contaminated soils (PCS) by: demonstrating bioremediation as a permanent method for remediating soils contaminated with petroleum products; establishing the best operating conditions for maximizing bioremediation and minimizing volatilization for SRS PCS during different seasons; determining the minimum set of analyses and sampling frequency to allow efficient and cost-effective operation; determining best use of existing site equipment and personnel to optimize facility operations and conserve SRS resources; and as an ancillary objective, demonstrating and optimizing new and innovative analytical techniques that will lower cost, decrease time, and decrease secondary waste streams for required PCS assays.

  20. Managing long-term polycyclic aromatic hydrocarbon contaminated soils: a risk-based approach.

    PubMed

    Duan, Luchun; Naidu, Ravi; Thavamani, Palanisami; Meaklim, Jean; Megharaj, Mallavarapu

    2015-06-01

    Polycyclic aromatic hydrocarbons (PAHs) are a family of contaminants that consist of two or more aromatic rings fused together. Soils contaminated with PAHs pose significant risk to human and ecological health. Over the last 50 years, significant research has been directed towards the cleanup of PAH-contaminated soils to background level. However, this achieved only limited success especially with high molecular weight compounds. Notably, during the last 5-10 years, the approach to remediate PAH-contaminated soils has changed considerably. A risk-based prioritization of remediation interventions has become a valuable step in the management of contaminated sites. The hydrophobicity of PAHs underlines that their phase distribution in soil is strongly influenced by factors such as soil properties and ageing of PAHs within the soil. A risk-based approach recognizes that exposure and environmental effects of PAHs are not directly related to the commonly measured total chemical concentration. Thus, a bioavailability-based assessment using a combination of chemical analysis with toxicological assays and nonexhaustive extraction technique would serve as a valuable tool in risk-based approach for remediation of PAH-contaminated soils. In this paper, the fate and availability of PAHs in contaminated soils and their relevance to risk-based management of long-term contaminated soils are reviewed. This review may serve as guidance for the use of site-specific risk-based management methods.

  1. Corrective Action Decision Document for Corrective Action Unit 166: Storage Yards and Contaminated Materials, Nevada Test Site, Nevada with Errata Sheet

    SciTech Connect

    Grant Evenson

    2007-03-01

    This Corrective Action Decision Document (CADD) has been prepared for Corrective Action Unit (CAU) 166, Storage Yards and Contaminated Materials, in accordance with the Federal Facility Agreement and Consent Order (1996). The corrective action sites (CASs) are located in Areas 2, 3, 5, and 18 of the Nevada Test Site, Nevada. Corrective Action Unit 166 is comprised of the following CASs: • 02-42-01, Cond. Release Storage Yd - North • 02-42-02, Cond. Release Storage Yd - South • 02-99-10, D-38 Storage Area • 03-42-01, Conditional Release Storage Yard • 05-19-02, Contaminated Soil and Drum • 18-01-01, Aboveground Storage Tank • 18-99-03, Wax Piles/Oil Stain The purpose of this CADD is to identify and provide the rationale for the recommendation of a corrective action alternative (CAA) for the seven CASs within CAU 166. Corrective action investigation (CAI) activities were performed from July 31, 2006, through February 28, 2007, as set forth in the CAU 166 Corrective Action Investigation Plan (NNSA/NSO, 2006).

  2. EFFECT OF SOIL PB INACTIVATION TREATMENTS ON BIOAVAILABILITY OF JOPLIN, MO, SMELTER CONTAMINATED SOIL PB TO RATS

    EPA Science Inventory

    The effects of treating contaminated soils with various soil amendments on the bioavailability of lead were assessed in the weanling rat model. The effect of treatment was assessed by comparing the adsorption of Pb of animals fed soil samples treated with (0.5%, 1% P and 2.5% Fe ...

  3. Effect of Soil Aging on the Phytoremediation Potential of Zea mays in Chromium and Benzo[a]Pyrene Contaminated Soils.

    PubMed

    Chigbo, Chibuike

    2015-06-01

    This study compared the phytoremediation potential of Zea mays in soil either aged or freshly amended with chromium (Cr) and benzo[a]pyrene (B[a]P). Z. mays showed increased shoot biomass in aged soils than in freshly spiked soils. The shoot biomass in contaminated soils increased by over 50% in aged soil when compared to freshly amended soils, and over 29% more Cr was accumulated in the shoot of Z. mays in aged soil than in freshly amended soil. Planting Z. mays in aged soil helped in the dissipation of more than 31% B[a]P than in freshly spiked soil, but in the absence of plants, there seemed to be no difference between the dissipation rates of B[a]P in freshly and aged co-contaminated soil. Z. mays seemed to enhance the simultaneous removal of Cr and B[a]P in aged soil than in freshly spiked soil and hence can be a good plant choice for phytoremediation of co-contaminated soils.

  4. Physicochemical and mineralogical characterization of transuranic contaminated soils for uranium soil integrated demonstration

    SciTech Connect

    Elless, M.P.; Lee, S.Y.

    1994-10-01

    DOE has initiated the Uranium Soils Integrated Demonstration (USID) project. The objective of the USID project is to develop a remediation strategy that can be adopted for use at other DOE sites requiring remediation. Four major task groups within the USID project were formed, namely the Characterization Task Group (CTG), the Treatability Task Group (TTG), the Secondary Waste Treatment and Disposal Task Group (SWTDTG), and the Risk and Performance Assessment Task Group (RPATG). The CTG is responsible for determining the nature of the uranium contamination in both untreated and treated soil. The TTG is responsible for the selective removal of uranium from these soils in such a manner that the leaching does not seriously degrade the soil`s physicochemical characteristics or generate a secondary waste form that is difficult to manage and/or dispose. The SWTDTG is responsible for developing strategies for the removal of uranium from all wastewaters generated by the TTGs. Finally the RPATG is responsible for developing the human health and environmental risk assessment of the untreated and treated soils. Because of the enormity of the work required to successfully remediate uranium-contaminated soils, an integrated approach was designed to avoid needless repetition of activities among the various participants in the USID project. Researchers from Oak Ridge National Laboratory (ORNL), Los Alamos National Laboratory (LANL), Argonne National Laboratory (ANL), and Idaho National Engineering Laboratory (INEL) were assigned characterization and/or treatability duties in their areas of specialization. All tasks groups are involved in the integrated approach; however, the thrust of this report concentrates on the utility of the integrated approach among the various members of the CTG. This report illustrates the use of the integrated approach for the overall CTG and to provide the results generated specifically by the CTG or ORNL from FY1993 to the present.

  5. [Strengthening Effects of Sodium Salts on Washing Kerosene Contaminated Soil with Surfactants].

    PubMed

    Huang, Zhao-lu; Chen, Quan-yuan; Zhou, Juan; Xie, Mo-han

    2015-05-01

    The impact of sodium salt on kerosene contaminated soil washing with surfactants was investigated. The results indicated that sodium silicate greatly enhanced the washing efficiency of SDS. Sodium tartrate can largely enhance the washing efficiency of SDBS and Brij35. Sodium salts can enhance the washing efficiency on kerosene contaminated with TX-100. No significant differences were observed between different sodium salts. Sodium salt of humic acid and sodium silicate had similar enhancement on kerosene contaminated soil washing with saponin. Sodium humate can be a better choice since its application can also improve soil quality. The enhancement of sodium silicate on kerosene contaminated soil washing with Tw-80 increased with the increase of Tw-80 dosage. However, the impact of sodium chloride and sodium tartrate was opposite to sodium silicate. Sodium salts can reduce surface tension and critical micelle concentration of ionic surfactants to enhance the washing. Sodium salts can also reduce re-adsorption of oil to soil with nonionic surfactants to enhance the washing. Kerosene contamination can increase the contact angle of soil, which indicated the increase of hydrophilicity of soil. Washing with surfactants can reduce the hydrophilicitiy of soil according to contact angle measurement, which indicated that kerosene contaminated soil remediation with surfactant can also benefit nutrient and water transportation in the contaminated soil.

  6. Calcium polysulfide treatment of Cr(VI)-contaminated soil.

    PubMed

    Chrysochoou, Maria; Ferreira, Daniel R; Johnston, Chad P

    2010-07-15

    Batch treatability studies for a Cr(VI)-contaminated glacial soil from a Cr plating facility were conducted using 1X and 2X the stoichiometric ratio of calcium polysulfide (CPS). The pH of the treated soil increased from 6 to 11 upon CPS addition, but progressively returned to 8-8.5 over the course of 1 year. The 1X dosage maintained a highly reducing environment up to 21 days of monitoring with the samples exposed to atmospheric oxygen, while 2X was reducing up to 180 days of curing. The EPA regulatory method for solid Cr(VI) could not reliably predict Cr(VI) in the treated solid due to ongoing reduction during the test. SPLP results showed that the CPS created an apparent Cr(VI) mobilization during the first 60 days of treatment, with subsequent decrease in soluble Cr(VI) up to 1 year of monitoring. Synchrotron micro-X-ray analyses at 60 days curing showed that Cr(VI) was predominantly bound as highly insoluble PbCrO(4) that precipitated in the interstitial pores of the soil, with very little to no Cr(VI) associated with the abundant iron oxyhydroxides. Despite its spatial accessibility and due to its low solubility, PbCrO(4) was recalcitrant to treatment, which proceeded only very slowly as judged by the SPLP data. It is concluded that, while CPS has a long residence time in the environment and is a promising reductant, in situ reduction is not an efficient treatment method for soils with highly insoluble Cr(VI) compounds, especially in surficial layers such as the one studied.

  7. Contamination of soils in the urbanized areas of Belarus with polycyclic aromatic hydrocarbons

    NASA Astrophysics Data System (ADS)

    Kukharchyk, T. I.; Khomich, V. S.; Kakareka, S. V.; Kurman, P. V.; Kozyrenko, M. I.

    2013-02-01

    The content of polycyclic aromatic hydrocarbons (PAHs) in the soils of urbanized areas, including the impact zones of Belarus, were studied. The concentrations of 16 PAHs in the soils were determined for individual and high-rise building zones, forests, and forest parks of Belarus. The levels of the PAH accumulation in the soils of different industrial enterprises and boiler stations were analyzed. Possible sources of soil contamination with PAHs were considered, and the structure of the PAHs in the soils was shown. The levels of the soil contamination were determined from the regulated parameters for individual compounds and the sum of 16 PAHs.

  8. Biochar- and phosphate-induced immobilization of heavy metals in contaminated soil and water: implication on simultaneous remediation of contaminated soil and groundwater.

    PubMed

    Liang, Yuan; Cao, Xinde; Zhao, Ling; Arellano, Eduardo

    2014-03-01

    Long-term wastewater irrigation or solid waste disposal has resulted in the heavy metal contamination in both soil and groundwater. It is often separately implemented for remediation of contaminated soil or groundwater at a specific site. The main objective of this study was to demonstrate the hypothesis of simultaneous remediation of both heavy metal contaminated soil and groundwater by integrating the chemical immobilization and pump-and-treat methods. To accomplish the objective, three experiments were conducted, i.e., an incubation experiment was first conducted to determine how dairy-manure-derived biochar and phosphate rock tailing induced immobilization of Cd in the Cd-contaminated soils; second, a batch sorption experiment was carried out to determine whether the pre-amended contaminated soil still had the ability to retain Pb, Zn and Cd from aqueous solution. BCR sequential extraction as well as XRD and SEM analysis were conducted to explore the possible retention mechanism; and last, a laboratory-scale model test was undertaken by leaching the Pb, Zn, and Cd contaminated groundwater through the pre-amended contaminated soils to demonstrate how the heavy metals in both contaminated soil and groundwater were simultaneously retained and immobilized. The incubation experiment showed that the phosphate biochar were effective in immobilizing soil Cd with Cd concentration in TCLP (toxicity characteristics leaching procedure) extract reduced by 19.6 % and 13.7 %, respectively. The batch sorption experiment revealed that the pre-amended soil still had ability to retain Pb, Zn, and Cd from aqueous solution. The phosphate-induced metal retention was mainly due to the metal-phosphate precipitation, while both sorption and precipitation were responsible for the metal stabilization in the biochar amendment. The laboratory-scale test demonstrated that the soil amended with phosphate removed groundwater Pb, Zn, and Cd by 96.4 %, 44.6 %, and 49.2 %, respectively, and the

  9. Biochar- and phosphate-induced immobilization of heavy metals in contaminated soil and water: implication on simultaneous remediation of contaminated soil and groundwater.

    PubMed

    Liang, Yuan; Cao, Xinde; Zhao, Ling; Arellano, Eduardo

    2014-03-01

    Long-term wastewater irrigation or solid waste disposal has resulted in the heavy metal contamination in both soil and groundwater. It is often separately implemented for remediation of contaminated soil or groundwater at a specific site. The main objective of this study was to demonstrate the hypothesis of simultaneous remediation of both heavy metal contaminated soil and groundwater by integrating the chemical immobilization and pump-and-treat methods. To accomplish the objective, three experiments were conducted, i.e., an incubation experiment was first conducted to determine how dairy-manure-derived biochar and phosphate rock tailing induced immobilization of Cd in the Cd-contaminated soils; second, a batch sorption experiment was carried out to determine whether the pre-amended contaminated soil still had the ability to retain Pb, Zn and Cd from aqueous solution. BCR sequential extraction as well as XRD and SEM analysis were conducted to explore the possible retention mechanism; and last, a laboratory-scale model test was undertaken by leaching the Pb, Zn, and Cd contaminated groundwater through the pre-amended contaminated soils to demonstrate how the heavy metals in both contaminated soil and groundwater were simultaneously retained and immobilized. The incubation experiment showed that the phosphate biochar were effective in immobilizing soil Cd with Cd concentration in TCLP (toxicity characteristics leaching procedure) extract reduced by 19.6 % and 13.7 %, respectively. The batch sorption experiment revealed that the pre-amended soil still had ability to retain Pb, Zn, and Cd from aqueous solution. The phosphate-induced metal retention was mainly due to the metal-phosphate precipitation, while both sorption and precipitation were responsible for the metal stabilization in the biochar amendment. The laboratory-scale test demonstrated that the soil amended with phosphate removed groundwater Pb, Zn, and Cd by 96.4 %, 44.6 %, and 49.2 %, respectively, and the

  10. Phytoremediation of dye contaminated soil by Leucaena leucocephala (subabul) seed and growth assessment of Vigna radiata in the remediated soil.

    PubMed

    Jayanthy, V; Geetha, R; Rajendran, R; Prabhavathi, P; Karthik Sundaram, S; Dinesh Kumar, S; Santhanam, P

    2014-09-01

    The present study was investigated for soil bioremediation through sababul plant biomass (Leucaena leucocephala). The soil contaminated with textile effluent was collected from Erode (chithode) area. Various physico-chemical characterizations like N, P, and K and electrical conductivity were assessed on both control and dye contaminated soils before and after remediation. Sababul (L. leucocephala) powder used as plant biomass for remediation was a tool for textile dye removal using basic synthetic dyes by column packing and eluting. The concentration of the dye eluted was compared with its original concentration of dye and were analyzed by using UV-vis spectrophotometer. Sababul plant biomass was analyzed for its physico-chemical properties and active compounds were detected by GC-MS, HPTLC and FTIR. Plant growth was assessed with green gram on the textile contaminated soil and sababul had the potential of adsorbing the dye as the contaminated soil and also check the growth of green gram. PMID:25183943

  11. Phytoremediation of dye contaminated soil by Leucaena leucocephala (subabul) seed and growth assessment of Vigna radiata in the remediated soil

    PubMed Central

    Jayanthy, V.; Geetha, R.; Rajendran, R.; Prabhavathi, P.; Karthik Sundaram, S.; Dinesh Kumar, S.; Santhanam, P.

    2013-01-01

    The present study was investigated for soil bioremediation through sababul plant biomass (Leucaena leucocephala). The soil contaminated with textile effluent was collected from Erode (chithode) area. Various physico-chemical characterizations like N, P, and K and electrical conductivity were assessed on both control and dye contaminated soils before and after remediation. Sababul (L. leucocephala) powder used as plant biomass for remediation was a tool for textile dye removal using basic synthetic dyes by column packing and eluting. The concentration of the dye eluted was compared with its original concentration of dye and were analyzed by using UV–vis spectrophotometer. Sababul plant biomass was analyzed for its physico-chemical properties and active compounds were detected by GC–MS, HPTLC and FTIR. Plant growth was assessed with green gram on the textile contaminated soil and sababul had the potential of adsorbing the dye as the contaminated soil and also check the growth of green gram. PMID:25183943

  12. Experimental increase in availability of a PAH complex organic contamination from an aged contaminated soil: consequences on biodegradation.

    PubMed

    Cébron, Aurélie; Faure, Pierre; Lorgeoux, Catherine; Ouvrard, Stéphanie; Leyval, Corinne

    2013-06-01

    Although high PAH content and detection of PAH-degraders, the PAH biodegradation is limited in aged-contaminated soils due to low PAH availability (i.e., 1%). Here, we tried to experimentally increase the soil PAH availability by keeping both soil properties and contamination composition. Organic extract was first removed and then re-incorporated in the raw soil as fresh contaminants. Though drastic, this procedure only allowed a 6-time increase in the PAH availability suggesting that the organic constituents more than ageing were responsible for low availability. In the re-contaminated soil, the mineralization rate was twice more important, the proportion of 5-6 cycles PAH was higher indicating a preferential degradation of lower molecular weight PAH. The extraction treatment induced bacterial and fungal community structures modifications, Pseudomonas and Fusarium solani species were favoured, and the relative quantity of fungi increased. In re-contaminated soil the percentage of PAH-dioxygenase gene increased, with 10 times more Gram negative representatives.

  13. Straw Compost and Bioremediated Soil as Inocula for the Bioremediation of Chlorophenol-Contaminated Soil

    PubMed Central

    Laine, M. M.; Jorgensen, K. S.

    1996-01-01

    We evaluated the use of straw compost and remediated soil as inocula for bioremediation of chlorophenol-contaminated soil. The in situ biotransformation of pentachlorophenol (PCP) and mineralization of radiolabeled [U-(sup14)C]PCP by straw compost and remediated soil were studied under field-simulating conditions before and after 3 months of adaptation with PCP in a percolator. After PCP adaptation, the straw compost mineralized up to 56% of the [(sup14)C]PCP. No partial dechlorination of PCP was found. The native straw compost did not mineralize PCP, but partial dechlorination of PCP occurred (i) at pH 8 under near-thermophilic conditions (45(deg)C) and (ii) at pH 7 under aerobic and mesophilic conditions. No biotransformation reactions occurred at room temperature (25(deg)C) at pH 8. Enrichment in the percolator enhanced the mineralization rate of remediated soil to 56% compared with that of the native remediated soil, which mineralized 24% of [(sup14)C]PCP added. Trace amounts of chloroanisoles as the only biotransformation products were detected in PCP-adapted remediated soil. Both inoculants studied here showed effective mineralization of PCP when they were adapted to PCP in the percolator. No harmful side reactions, such as extensive methylation, were observed. PMID:16535304

  14. Photo-Fenton treatment of TNT contaminated soil extract solutions obtained by soil flushing with cyclodextrin.

    PubMed

    Yardin, Gwenine; Chiron, Serge

    2006-03-01

    The technical feasibility and performances of coupling flushing abilities of cyclodextrin solutions for 2,4,6-trinitrotoluene (TNT) removal from contaminated soil and the ability of Photo-Fenton treatment for final disposal of soil extract solutions containing high TNT loads have been investigated at laboratory scale. Methylated-beta-cyclodextrin (MCD) has shown better ability than hydroxypropyl-beta-cyclodextrin (HPCD) to complex TNT. The MCD solution increased the aqueous concentration of TNT in soil extract effluents as much as 2.1 times the concentrations obtained during the water flush of the soil. TNT in soil extract solution has been treated by Photo-Fenton. Our results indicate that MCD has a beneficial effect on the degradation rates of TNT. This relative improvement of TNT degradation rate (1.3 time) in presence of high amounts of hydroxyl radical scavengers can be ascribed to the formation of a ternary complex (TNT-cyclodextrin-iron) which can direct hydroxyl radical reaction toward TNT. Complete mineralization of soil extraction solutions was not achieved and TNT degradation pathway has been elucidated in order to ensure that no potential toxic intermediate is left at the end of the treatment time. After successive TNT hydroxylations, oxidative opening of the TNT aromatic ring quickly occurred, leading to the accumulation of short chain carboxylic acids such as oxalic acid and formic acid.

  15. Cysteine-β-cyclodextrin enhanced phytoremediation of soil co-contaminated with phenanthrene and lead.

    PubMed

    Wang, Guanghui; Wang, Yin; Hu, Suhang; Deng, Nansheng; Wu, Feng

    2015-07-01

    It is necessary to find an effective soil remediation technology for the simultaneous removal of hydrophobic organic contaminants and heavy metals from contaminated soils. In this work, a novel cysteine-β-cyclodextrin (CCD) was synthesized by the reaction of β-cyclodextrin with cysteine, and the structure of CCD was confirmed by (1)H-NMR, (13)C-NMR, FT-IR spectroscopy and elemental analysis. Pot-culture experiments were conducted to investigate the effects of CCD on the phytoremediation of soil co-contaminated with phenanthrene and lead. The results showed that CCD can enhance the phytoremediation of soil co-contaminated with phenanthrene and lead. When CCD was added to the co-contaminated soil, the concentrations of phenanthrene and Pb in roots and shoots of ryegrass (Lolium perenne L.) significantly increased, the presence of CCD is beneficial to the accumulation of phenanthrene and Pb in ryegrass, and the residual concentrations of phenanthrene and Pb in soils significantly decreased. Under the co-contamination of 500 mg Pb kg(-1) and 50 mg PHE kg(-1), the bioconcentration factor of phenanthrene and Pb in the presence of CCD was increased by 1.43-fold and 4.47-fold, respectively. After CCD was added to the contaminated soils, the residual concentration of phenanthrene and Pb in unplanted soil was decreased by 18 and 25%, respectively. However, for the planted soil, the residual concentration of phenanthrene and Pb was decreased by 48 and 56%, respectively. CCD may improve the bioavailability of phenanthrene and Pb in co-contaminated soil; CCD enhanced phytoremediation technology may be a good alternative for the removal of hydrophobic organic contaminants and heavy metals from contaminated soils.

  16. AIR EMISSIONS FROM THE TREATMENT OF SOILS CONTAMINATED WITH PETROLEUM FUELS AND OTHER SUBSTANCES

    EPA Science Inventory

    The report updates a 1992 report that summarizes available information on air emissions from the treatment of soils contaminated with fuels. Soils contaminated by leaks or spills of fuel products, such as gasoline or jet fuel, are a nationwide concern. Air emissions during remedi...

  17. Isolation and identification of dioxin degrading bacteria found in soils contaminated with dioxins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a need to identify bacteria that can degrade environmental contaminants; a fruitful place to identify such bacteria is within contaminated soil. The dioxin content and congener distribution in soils collected from adjacent to old railroad track that were treated with pentachlorophenol (PCP...

  18. PHYTOREMEDIATION OF SOILS CONTAMINATED WITH WOOD PRESERVATIVES: GREENHOUSE AND FIELD EVALUATIONS

    EPA Science Inventory

    Phytoremediation was evaluated as a potential treatment for the creosote-contaminated surface soil at the McCormick and Baxter (M&B) Superfund Site in Portland, OR. Soil a the M&B site is contaminated with pentachlorophenol (PCP) and polyaromatic hydrocarbons (PAHs). Eight indivi...

  19. Phosphate Treatment of Lead-Contaminated Soil: Effects on Water Quality, Plant Uptake, and Lead Speciation

    EPA Science Inventory

    Water quality threats associated with using phosphate-based amendments to remediate Pb-contaminated soils are a concern, particularly in riparian areas. This study investigated the effects of P application rates to a Pb-contaminated alluvial soil on Pb and P loss via surface wat...

  20. Contaminant Immobilization and Nutrient Release by Biochar Soil Amendment: Roles of Natural Organic Matter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Contamination of soil interstitial waters by labile heavy metals such as CuII, CdII, and NiII is of worldwide concern. Carbonaceous materials such as char and activated carbon have received considerable attention in recent years as soil amendment for both sequestering heavy metal contaminants and r...

  1. Evaluation of soil amendments as a remediation alternative for cadmium-contaminated soils under cacao plantations.

    PubMed

    Chavez, E; He, Z L; Stoffella, P J; Mylavarapu, R; Li, Y; Baligar, V C

    2016-09-01

    Elevated plant-available cadmium (Cd) in soils results in contamination to cacao (Theobroma cacao L) beans. Effectiveness of vermicompost and zeolite in reducing available Cd in three cacao-growing soils was studied under laboratory conditions. Sorption-desorption experiments were conducted in soils and amendments. Cadmium was added at 0 or 5 mg kg(-1) (spiked), then, amendments were incorporated at 0, 0.5, or 2 %. Amended soils were incubated at room temperature for 28 days. Plant-available Cd was determined using 0.01 M CaCl2 (WSE) and Mehlich 3 (M3) extraction procedures in subsamples taken from individual bags at six time intervals. Soils and amendments displayed different sorption characteristics and a better fit was attained with Freundlich model (R (2) > 0.82). Amendments were ineffective in reducing extractable Cd in non-spiked soils. In Cd-spiked soils, vermicompost at 2 % significantly reduced WSE-Cd (P < 0.01) from 3.36, 0.54, and 0.38 mg kg(-1) to values lower that instrument's detection in all the three soils and significantly diminished M3-extractable Cd (P < 0.05) from 4.62 to 4.11 mg kg(-1) in only one soil. Vermicompost at 0.5 % significantly decreased WSE-Cd (P < 0.01) from 3.04 and 0.31 to 1.69 and 0.20 mg kg(-1), respectively, in two soils with low sorption capacity for Cd. In contrast, zeolite failed to reduce WSE- or M3-extractable Cd in all studied soils. A negative correlation occurred between soil pH and WSE-Cd (r > -0.89, P < 0.01). The decrease in WSE-Cd appears to be associated with the increase in pH of the vermicompost-amended soils. PMID:27234831

  2. Evaluation of soil amendments as a remediation alternative for cadmium-contaminated soils under cacao plantations.

    PubMed

    Chavez, E; He, Z L; Stoffella, P J; Mylavarapu, R; Li, Y; Baligar, V C

    2016-09-01

    Elevated plant-available cadmium (Cd) in soils results in contamination to cacao (Theobroma cacao L) beans. Effectiveness of vermicompost and zeolite in reducing available Cd in three cacao-growing soils was studied under laboratory conditions. Sorption-desorption experiments were conducted in soils and amendments. Cadmium was added at 0 or 5 mg kg(-1) (spiked), then, amendments were incorporated at 0, 0.5, or 2 %. Amended soils were incubated at room temperature for 28 days. Plant-available Cd was determined using 0.01 M CaCl2 (WSE) and Mehlich 3 (M3) extraction procedures in subsamples taken from individual bags at six time intervals. Soils and amendments displayed different sorption characteristics and a better fit was attained with Freundlich model (R (2) > 0.82). Amendments were ineffective in reducing extractable Cd in non-spiked soils. In Cd-spiked soils, vermicompost at 2 % significantly reduced WSE-Cd (P < 0.01) from 3.36, 0.54, and 0.38 mg kg(-1) to values lower that instrument's detection in all the three soils and significantly diminished M3-extractable Cd (P < 0.05) from 4.62 to 4.11 mg kg(-1) in only one soil. Vermicompost at 0.5 % significantly decreased WSE-Cd (P < 0.01) from 3.04 and 0.31 to 1.69 and 0.20 mg kg(-1), respectively, in two soils with low sorption capacity for Cd. In contrast, zeolite failed to reduce WSE- or M3-extractable Cd in all studied soils. A negative correlation occurred between soil pH and WSE-Cd (r > -0.89, P < 0.01). The decrease in WSE-Cd appears to be associated with the increase in pH of the vermicompost-amended soils.

  3. Analysis of predictors related to soil contamination in recreational areas of Romania.

    PubMed

    Gagiu, C; Pica, E M; Querol, X; Botezan, C S

    2015-12-01

    Soil contamination in recreational areas can considerably affect children's health, as they are the segment of the population most sensitive to anthropogenic contamination. Soil contamination in recreational areas is influenced by a number of factors such as type and age of the recreational area, nearby traffic intensity, proximity to industrial areas, presence of vegetation, level of usage, treated wood structures, and the extent of maintenance operations carried out in the area. These can most often be observed during a simple site visit. The purpose of the present research is to analyze to which extent the presence of these factors can trigger an alarm signal, highlighting soil contamination in urban recreational areas. In this regard, soil contamination was scaled using the integrated pollution index applied on nine distinctive contaminants (As, Cu, Cd, Zn, Pb, Hg, Co, Ni, Mg) identified using inductively coupled plasma mass spectrometry (ICP-MS). Multiple linear regression analysis was performed in order to assess predictors of soil contamination. The research was carried out in a number of 88 recreational areas, parks, and playgrounds from 19 Romanian cities, revealing the fact that proximity to industrial areas and intensive traffic had statistically significant effects on soil contamination. Furthermore, it was observed that in 78 out of the 88 analyzed locations, the concentrations of contaminants exceeded the guidelines established through national legislation, thus confirming the presumption that high concentrations of contaminants exist in the parks and playgrounds of Romania.

  4. Chelant extraction and REDOX manipulation for mobilization of heavy metals from contaminated soils

    SciTech Connect

    Brewster, M.D.; Peters, R.W.; Miller, G.A.; Patton, T.L.; Martino, L.E.

    1994-12-01

    Was the result of open burning and open detonation of chemical agents and munitions in the Toxic Burning Pits area at J-Field, located in the Edgewood Area of Aberdeen Proving Ground in Harford County, Maryland, soils have been contaminated with heavy metals. Simultaneous extraction is complicated because of the multitude of contaminant forms that exist. This paper uses data from a treatability study performed at Argonne National Laboratory to discuss and compare several treatment methods that were evaluated for remediating metals-contaminated soils. J-Field soils were subjected to a series of treatability experiments designed to determine the feasibility of using soil washing/soil flushing, enhancements to soil washing/soil flushing, solidification/stabilization, and electrokinetics for remediating soils contaminated with metals. Chelating and mobilizing agents evaluated included ammonium acetate, ethylenediaminetetraacetic acid, citric acid, Citranox, gluconic acid, phosphoric acid, oxalic acid, and nitrilotriacetic acid, in addition to pH-adjusted water. REDOX manipulation can maximize solubilities, increase desorption, and promote removal of heavy metal contaminants. Reducing agents that were studied included sodium borohydride, sodium metabisulfite, and thiourea dioxide. The oxidants studied included hydrogen peroxide, sodium percarbonate, sodium hypochlorite, and potassium permanganate. This paper summaries the results from the physical/chemical characterization, soil washing/soil flushing, and enhancements to soil washing/soil flushing portions of the study.

  5. Bioremediation: An effective remedial alternative for petroleum hydrocarbon-contaminated soil

    SciTech Connect

    Autry, A.R.; Ellis, G.M. )

    1992-11-01

    Bioremediation technologies applied to contaminated soil usually mitigate environmental rate-limiting factors so that biodegradation rates are maximized for any given compound. A newer approach to soil bioremediation mitigates these environmental rate-limiting factors simultaneously, initially allowing biodegradation to proceed at a maximal rate without the need for additional action. This technology involves intensive mixing of contaminated soil in a ribbon blender, introduction of a protein-based, surfactant-containing nutrient additive to the soil while in the mixer, physical entrainment of oxygen-containing air into the soil, discharge of the mixed soil from the mixer, and placement of the mixed soil in curing piles, for curing, during which time biodegradation can occur. No additional treatment actions (e.g., tillage, fertilizer or water applications) are typically required. The remediation, using this approach, of a former distribution facility which possessed soil contaminated with gasoline, is summarized. 22 refs., 6 figs.

  6. Selection of surfactant in remediation of DDT-contaminated soil by comparison of surfactant effectiveness.

    PubMed

    Guo, Ping; Chen, Weiwei; Li, Yueming; Chen, Tao; Li, Linhui; Wang, Guanzhu

    2014-01-01

    With an aim to select the most appropriate surfactant for remediation of DDT-contaminated soil, the performance of nonionic surfactants Tween80, TX-100, and Brij35 and one anionic surfactant sodium dodecyl benzene sulfonate (SDBS) in enhancement of DDT water solubility and desorption of DDT from contaminated soil and their adsorption onto soil and ecotoxicities were investigated in this study. Tween80 had the highest solubilizing and soil-washing ability for DDT among the four experimental surfactants. The adsorption loss of surfactants onto soil followed the order of TX-100 > Tween80 > Brij35 > SDBS. The ecotoxicity of Tween80 to ryegrass (Lolium perenne L.) was lowest. The overall performance considering about the above four aspects suggested that Tween80 should be selected for the remediation of DDT-contaminated soil, because Tween80 had the greatest solubilizing and soil-washing ability for DDT, less adsorption loss onto soil, and the lowest ecotoxicity in this experiment.

  7. Efficiency of non-ionic surfactants - EDTA for treating TPH and heavy metals from contaminated soil

    PubMed Central

    2013-01-01

    Introduction of fuel hydrocarbons and inorganic compounds (heavy metals) into the soil, resulting in a change of the soil quality, which is likely to affect use of the soil or endangering public health and ground water. This study aimed to determine a series of parameters to remediation of TPH and heavy metals contaminated soil by non-ionic surfactants- chelating agents washing process. In this experimental study, the effects of soil washing time, agitation speed, concentration of surfactant, chelating agent and pH on the removal efficiency were studied. The results showed that TPH removal by nonionic surfactants (Tween 80, Brij 35) in optimal condition were 70–80% and 60–65%, respectively. Addition of chelating agent (EDTA) significantly increases Cd and Pb removal. The washing of soil by non- ionic surfactants and EDTA was effective in remediation of TPH and heavy metals from contaminated soil, thus it can be recommended for remediation of contaminated soil. PMID:24359927

  8. [Immobilization remediation of Cd and Pb contaminated soil: remediation potential and soil environmental quality].

    PubMed

    Sun, Yue-Bing; Wang, Peng-Chao; Xu, Ying-Ming; Sun, Yang; Qin, Xu; Zhao, Li-Jie; Wang, Lin; Liang, Xue-Feng

    2014-12-01

    A pot experiment was conducted to investigate the immobilization remediation effects of sepiolite on soils artificially combined contamination by Cd and Pb using a set of various pH and speciation of Cd and Pb in soil, heavy metal concentration in Oryza sativa L., and soil enzyme activity and microbial quantity. Results showed that the addition of sepiolite increased the soil pH, and the exchangeable fraction of heavy metals was converted into Fe-Mn oxide, organic and residual forms, the concentration of exchangeable form of Cd and Pb reduced by 1.4% - 72.9% and 11.8% - 51.4%, respectively, when compared with the control. The contents of heavy metals decreased with increasing sepiolite, with the maximal Cd reduction of 39.8%, 36.4%, 55.2% and 32.4%, respectively, and 22.1%, 54.6%, 43.5% and 17.8% for Pb, respectively, in the stems, leaves, brown rice and husk in contrast to CK. The addition of sepiolite could improve the soil environmental quality, the catalase and urease activities and the amount of bacteria and actinomycete were increased to some extents. Although the fungi number and invertase activity were inhibited compared with the control group, it was not significantly different (P > 0.05). The significant correlation between pH, available heavy metal content, urease and invertase activities and heavy metal concentration in the plants indicated that these parameters could be used to evaluate the effectiveness of stabilization remediation of heavy metal contaminated soil.

  9. [Immobilization remediation of Cd and Pb contaminated soil: remediation potential and soil environmental quality].

    PubMed

    Sun, Yue-Bing; Wang, Peng-Chao; Xu, Ying-Ming; Sun, Yang; Qin, Xu; Zhao, Li-Jie; Wang, Lin; Liang, Xue-Feng

    2014-12-01

    A pot experiment was conducted to investigate the immobilization remediation effects of sepiolite on soils artificially combined contamination by Cd and Pb using a set of various pH and speciation of Cd and Pb in soil, heavy metal concentration in Oryza sativa L., and soil enzyme activity and microbial quantity. Results showed that the addition of sepiolite increased the soil pH, and the exchangeable fraction of heavy metals was converted into Fe-Mn oxide, organic and residual forms, the concentration of exchangeable form of Cd and Pb reduced by 1.4% - 72.9% and 11.8% - 51.4%, respectively, when compared with the control. The contents of heavy metals decreased with increasing sepiolite, with the maximal Cd reduction of 39.8%, 36.4%, 55.2% and 32.4%, respectively, and 22.1%, 54.6%, 43.5% and 17.8% for Pb, respectively, in the stems, leaves, brown rice and husk in contrast to CK. The addition of sepiolite could improve the soil environmental quality, the catalase and urease activities and the amount of bacteria and actinomycete were increased to some extents. Although the fungi number and invertase activity were inhibited compared with the control group, it was not significantly different (P > 0.05). The significant correlation between pH, available heavy metal content, urease and invertase activities and heavy metal concentration in the plants indicated that these parameters could be used to evaluate the effectiveness of stabilization remediation of heavy metal contaminated soil. PMID:25826946

  10. Phyotoxicity of diesel soil contamination on the germination of Lactuca sativa and Ipomoea batatas.

    PubMed

    Fatokun, Kayode; Lewu, Francis Bayo; Zharare, Godfrey Elijah

    2015-11-01

    Phytotoxic effect of diesel contaminated soil on germination rate of Lactuca sativa and Ipomoea batatas, at two concentrations ranges (0-6ml and 0-30ml), were investigated and compared. Diesel soil contamination was simulated and soil samples were taken from contaminated soil at 1, 5,10, 15, 25, 50, 75 and 100 days should be after planting. The result showed that in both plant species, diesel inhibited germination in a concentration dependent manner, Also, the influence of diesel contamination diminished with increased time duration; suggesting possible reduction in diesel toxicity over time. However, germination of lettuce was significant and negatively correlated (r2 = -0.941) with diesel contamination as compared to sweet potato (r2 = -0.638).Critical concentration of diesel in relation to seed germination of L. sativa was lower than vegetative germination of I. batatas, indicating that germination of I. batatas was less sensitive to diesel contamination as compared to L. sativa.

  11. Plant communities in relation to flooding and soil contamination in a lowland Rhine River floodplain.

    PubMed

    Schipper, Aafke M; Lotterman, Kim; Leuven, Rob S E W; Ragas, Ad M J; de Kroon, Hans; Hendriks, A Jan

    2011-01-01

    Using canonical correspondence analysis (CCA), relationships were investigated between plant species composition and flooding characteristics, heavy metal contamination and soil properties in a lowland floodplain of the Rhine River. Floodplain elevation and yearly average flooding duration turned out to be more important for explaining variation in plant species composition than soil heavy metal contamination. Nevertheless, plant species richness and diversity showed a significant decrease with the level of contamination. As single heavy metal concentrations seemed mostly too low for causing phytotoxic effects in plants, this trend is possibly explained by additive effects of multiple contaminants or by the concomitant influences of contamination and non-chemical stressors like flooding. These results suggest that impacts of soil contamination on plants in floodplains could be larger than expected from mere soil concentrations. In general, these findings emphasize the relevance of analyzing effects of toxic substances in concert with the effects of other relevant stressors.

  12. Phyotoxicity of diesel soil contamination on the germination of Lactuca sativa and Ipomoea batatas.

    PubMed

    Fatokun, Kayode; Lewu, Francis Bayo; Zharare, Godfrey Elijah

    2015-11-01

    Phytotoxic effect of diesel contaminated soil on germination rate of Lactuca sativa and Ipomoea batatas, at two concentrations ranges (0-6ml and 0-30ml), were investigated and compared. Diesel soil contamination was simulated and soil samples were taken from contaminated soil at 1, 5,10, 15, 25, 50, 75 and 100 days should be after planting. The result showed that in both plant species, diesel inhibited germination in a concentration dependent manner, Also, the influence of diesel contamination diminished with increased time duration; suggesting possible reduction in diesel toxicity over time. However, germination of lettuce was significant and negatively correlated (r2 = -0.941) with diesel contamination as compared to sweet potato (r2 = -0.638).Critical concentration of diesel in relation to seed germination of L. sativa was lower than vegetative germination of I. batatas, indicating that germination of I. batatas was less sensitive to diesel contamination as compared to L. sativa. PMID:26688970

  13. Soil pollution in the railway junction Niš (Serbia) and possibility of bioremediation of hydrocarbon-contaminated soil

    NASA Astrophysics Data System (ADS)

    Jovanovic, Larisa; Aleksic, Gorica; Radosavljevic, Milan; Onjia, Antonije

    2015-04-01

    Mineral oil leaking from vehicles or released during accidents is an important source of soil and ground water pollution. In the railway junction Niš (Serbia) total 90 soil samples polluted with mineral oil derivatives were investigated. Field work at the railway Niš sites included the opening of soil profiles and soil sampling. The aim of this work is the determination of petroleum hydrocarbons concentration in the soil samples and the investigation of the bioremediation technique for treatment heavily contaminated soil. For determination of petroleum hydrocarbons in the soil samples method of gas-chromatography was carried out. On the basis of measured concentrations of petroleum hydrocarbons in the soil it can be concluded that: Obtained concentrations of petroleum hydrocarbons in 60% of soil samples exceed the permissible values (5000 mg/kg). The heavily contaminated soils, according the Regulation on the program of systematic monitoring of soil quality indicators for assessing the risk of soil degradation and methodology for development of remediation programs, Annex 3 (Official Gazette of RS, No.88 / 2010), must be treated using some of remediation technologies. Between many types of phytoremediation of soil contaminated with mineral oils and their derivatives, the most suitable are phytovolatalisation and phytostimulation. During phytovolatalisation plants (poplar, willow, aspen, sorgum, and rye) absorb organic pollutants through the root, and then transported them to the leaves where the reduced pollutants are released into the atmosphere. In the case of phytostimulation plants (mulberry, apple, rye, Bermuda) secrete from the roots enzymes that stimulates the growth of bacteria in the soil. The increase in microbial activity in soil promotes the degradation of pollutants. Bioremediation is performed by composting the contaminated soil with addition of composting materials (straw, manure, sawdust, and shavings), moisture components, oligotrophs and

  14. Chemically enhanced phytoextraction of lead-contaminated soils.

    PubMed

    Perry, V Ryan; Krogstad, Eirik J; El-Mayas, Hanan; Greipsson, Sigurdur

    2012-08-01

    The effects of the combined application of soil fungicide (benomyl) and ethylenediaminetetraacetic acid (EDTA) on lead (Pb) phytoextraction by ryegrass (Lolium perenne) were examined. Twenty-five pots of Pb-contaminated soil (200 mg Pb kg(-1)) were seeded with ryegrass and randomly arranged into the following treatments: (1) Control, (2) benomyl, (3) EDTA, (4) benomyl and EDTA (B+E), and (5) benomyl followed by an application of EDTA 14 days later (B .. . E). Chemicals were applied when plants had reached maximum growth. Plants were analyzed for foliage Pb concentration using inductively coupled argon plasma (ICAP) spectrometry. The synergistic effects of the combined benomyl and EDTA application (treatments 4 and 5) were made evident by the significantly (p < 0.05) highest foliage Pb concentrations. However, the foliage dry biomass was significantly lowest for plants in treatments 4 and 5. The bioaccumulation factor (BF) and phytoextraction ratio (PR) were highest for plants in treatment 5 followed by plants in treatment 4. PMID:22908638

  15. [Immobilization impact of different fixatives on heavy metals contaminated soil].

    PubMed

    Wu, Lie-shan; Zeng, Dong-mei; Mo, Xiao-rong; Lu, Hong-hong; Su, Cui-cui; Kong, De-chao

    2015-01-01

    Four kinds of amendments including humus, ammonium sulfate, lime, superphosphate and their complex combination were added to rapid immobilize the heavy metals in contaminated soils. The best material was chosen according to the heavy metals' immobilization efficiency and the Capacity Values of the fixative in stabilizing soil heavy metals. The redistributions of heavy metals were determined by the European Communities Bureau of Referent(BCR) fraction distribution experiment before and after treatment. The results were as follows: (1) In the single material treatment, lime worked best with the dosage of 2% compared to the control group. In the compound amendment treatments, 2% humus combined with 2% lime worked best, and the immobilization efficiency of Pb, Cu, Cd, Zn reached 98.49%, 99.40%, 95.86%, 99.21%, respectively. (2) The order of Capacity Values was lime > humus + lime > ammonium sulfate + lime > superphosphate > ammonium sulfate + superphosphate > humus + superphosphate > humus > superphosphate. (3) BCR sequential extraction procedure results indicated that 2% humus combined with 2% lime treatment were very effective in immobilizing heavy metals, better than 2% lime treatment alone. Besides, Cd was activated firstly by 2% humus treatment then it could be easily changed into the organic fraction and residual fraction after the subsequent addition of 2% lime. PMID:25898680

  16. [Immobilization impact of different fixatives on heavy metals contaminated soil].

    PubMed

    Wu, Lie-shan; Zeng, Dong-mei; Mo, Xiao-rong; Lu, Hong-hong; Su, Cui-cui; Kong, De-chao

    2015-01-01

    Four kinds of amendments including humus, ammonium sulfate, lime, superphosphate and their complex combination were added to rapid immobilize the heavy metals in contaminated soils. The best material was chosen according to the heavy metals' immobilization efficiency and the Capacity Values of the fixative in stabilizing soil heavy metals. The redistributions of heavy metals were determined by the European Communities Bureau of Referent(BCR) fraction distribution experiment before and after treatment. The results were as follows: (1) In the single material treatment, lime worked best with the dosage of 2% compared to the control group. In the compound amendment treatments, 2% humus combined with 2% lime worked best, and the immobilization efficiency of Pb, Cu, Cd, Zn reached 98.49%, 99.40%, 95.86%, 99.21%, respectively. (2) The order of Capacity Values was lime > humus + lime > ammonium sulfate + lime > superphosphate > ammonium sulfate + superphosphate > humus + superphosphate > humus > superphosphate. (3) BCR sequential extraction procedure results indicated that 2% humus combined with 2% lime treatment were very effective in immobilizing heavy metals, better than 2% lime treatment alone. Besides, Cd was activated firstly by 2% humus treatment then it could be easily changed into the organic fraction and residual fraction after the subsequent addition of 2% lime.

  17. Assessing the technogenic contamination of urban soils from the profile distribution of heavy metals and the soil bulk density

    NASA Astrophysics Data System (ADS)

    Korchagina, K. V.; Smagin, A. V.; Reshetina, T. V.

    2014-08-01

    The contamination of soils with heavy metals in the city of Moscow has been assessed using the conventional procedure and a new resource approach developed at the Faculty of Soil Science of Moscow State University. The approach involved the consideration of the profile distribution of a pollutant and the variation in the bulk density of the enclosing soil. The integral parameter of contamination was the reserve of the pollutant in a conventional normative soil layer 1 m in thickness according to the Moscow Law On the Urban Soils. In the soil samples taken in the main administrative districts of Moscow, the contents of heavy metals of the first (zinc, lead, cadmium, arsenic, and mercury) and second (nickel and copper) hazard classes were determined. For each profile, distribution graphs of all of the above elements have been developed, and the element reserves have been calculated in the upper 1-m-thick layer with consideration for the changes in the soil density with depth. The obtained data have been compared with the normative reserves of heavy metals and the estimates of technogenic contamination derived using the conventional procedure. An increase in the total reserves of pollutants has been observed at the increase in their concentrations with depth; therefore, a clean soil according to the conventional procedure can be classified as contaminated. Analogously, a decrease in the total reserve of a pollutant in the upper 1-m-thik layer and, hence, a decrease in the degree of soil contamination have been observed when the concentration of the pollutant reduced with the depth. In general, the profile distributions of heavy metals and the soil bulk density strongly interfere with the estimation of the contamination of the soil as a spatially heterogeneous body and should be taken into consideration in the development of a present-day system of quality criteria and norms for urban soils.

  18. Toxicity assessment for petroleum-contaminated soil using terrestrial invertebrates and plant bioassays.

    PubMed

    Hentati, Olfa; Lachhab, Radhia; Ayadi, Mariem; Ksibi, Mohamed

    2013-04-01

    The assessment of soil quality after a chemical or oil spill and/or remediation effort may be measured by evaluating the toxicity of soil organisms. To enhance our understanding of the soil quality resulting from laboratory and oil field spill remediation, we assessed toxicity levels by using earthworms and springtails testing and plant growth experiments. Total petroleum hydrocarbons (TPH)-contaminated soil samples were collected from an oilfield in Sfax, Tunisia. Two types of bioassays were performed. The first assessed the toxicity of spiked crude oil (API gravity 32) in Organization for Economic Co-operation and Development artificial soil. The second evaluated the habitat function through the avoidance responses of earthworms and springtails and the ability of Avena sativa to grow in TPH-contaminated soils diluted with farmland soil. The EC50 of petroleum-contaminated soil for earthworms was 644 mg of TPH/kg of soil at 14 days, with 67 % of the earthworms dying after 14 days when the TPH content reached 1,000 mg/kg. The average germination rate, calculated 8 days after sowing, varied between 64 and 74 % in low contaminated soils and less than 50 % in highly contaminated soils. PMID:22773148

  19. Risk perception of heavy metal soil contamination and attitudes toward decontamination strategies.

    PubMed

    Weber, O; Scholz, R W; Bühlmann, R; Grasmück, D

    2001-10-01

    Contaminated soils are a common environmental risk all over the world. One major source of risk is heavy metal soil contamination caused by industrial emissions. This quasiexperimental study investigated the perception of these risks by exposed and nonexposed people, their attitudes toward bioremediation methods using hyperaccumulating plants, and the influence of long-term aspects of sustainability on the acceptance of bioremediation methods. Major findings were that people living in a contaminated area perceived the risk of the heavy metal soil contamination as higher than the general risk of contamination. Second, a factor analysis showed that the factors dread, control, and catastrophic potential were relevant for the perception and valuation of low-dose environmental risks such as the contamination of the investigated area. In addition, a cluster analysis showed that the risk of heavy metal soil contamination was perceived as similar to that of oil contamination, ozone layer, preservatives and genetic technology. It was perceived indifferently with regard to dread. The uncontrollability of heavy metal soil contamination was estimated as medium, and its catastrophic potential as low. Third, exposed and nonexposed participants preferred bioremediation methods to classical methods (e.g., excavation and chemical treatment of the soil), because they perceived the environmental and esthetical performance of the bioremediation as important criteria. Sustainability or precautionary issues, such as the prevention of harm for future generations, were highly correlated with the acceptance of the use of bioremediation methods in people's residential areas.

  20. Managed bioremediation of soil contaminated with crude oil soil chemistry and microbial ecology three years later.

    PubMed

    Duncan, K; Levetin, E; Wells, H; Jennings, E; Hettenbach, S; Bailey, S; Lawlor, K; Sublette, K; Berton Fisher, J

    1997-01-01

    Analysis of samples taken from three experimental soil lysimeters demonstrated marked long-term effects of managed bioremediation on soil chemistry and on bacterial and fungal communities 3 yr after the application of crude oil or crude oil and fertilizer. The lysimeters were originally used to evaluate the short-term effectiveness of managed (application of fertilizer and water, one lysimeter) vs unmanaged bioremediation (one lysimeter) of Michigan Silurian crude oil compared to one uncontaminated control lysimeter. Three years following the original experiment, five 2-ft-long soil cores were extracted from each lysimeter, each divided into three sections, and the like sections mixed together to form composited soil samples. All subsequent chemical and microbiological analyses were performed on these nine composited samples. Substantial variation was found among the lysimeters for certain soil chemical characteristics (% moisture, pH, total Kjeldahl nitrogen [TKN], ammonia nitrogen [NH4-N], phosphate phosphorous [PO4-P], and sulfate [SO4 (-2)]). The managed lysimeter had 10% the level of total petroleum hydrocarbons (TPH-IR) found in the unmanaged lysimeter. Assessment of the microbial community was performed for heterotropic bacteria, fungi, and aromatic hydrocarbon-degrading bacteria (toluene, naphthalene, and phenanthrene) by dilution onto solid media. There was little difference in the number of heterotrophic bacteria, in contrast to counts of fungi, which were markedly higher in the contaminated lysimeters. Hydrocarbon-degrading bacteria were elevated in both oil-contaminated lysimeters. In terms of particular hydrocarbons as substrates, phenanthrene degraders were greater in number than naphthalene degraders, which outnumbered toluene degraders. Levels of sulfate-reducing bacteria seem to have been stimulated by hydrocarbon degradation. PMID:18576141

  1. Construction of a chemical ranking system of soil pollution substances for screening of priority soil contaminants in Korea.

    PubMed

    Jeong, Seung-Woo; An, Youn-Joo

    2012-04-01

    The Korean government recently proposed expanding the number of soil-quality standards to 30 by 2015. The objectives of our study were to construct a reasonable protocol for screening priority soil contaminants for inclusion in the planned soil quality standard expansion. The chemical ranking system of soil pollution substances (CROSS) was first developed to serve as an analytical tool in chemical scoring and ranking of possible soil pollution substances. CROSS incorporates important parameters commonly used in several previous chemical ranking and scoring systems and the new soil pollution parameters. CROSS uses soil-related parameters in its algorithm, including information related to the soil environment, such as soil ecotoxicological data, the soil toxic release inventory (TRI), and soil partitioning coefficients. Soil TRI and monitoring data were incorporated as local specific parameters. In addition, CROSS scores the transportability of chemicals in soil because soil contamination may result in groundwater contamination. Dermal toxicity was used in CROSS only to consider contact with soil. CROSS uses a certainty score to incorporate data uncertainty. CROSS scores the importance of each candidate substance and assigns rankings on the basis of total scores. Cadmium was the most highly ranked. Generally, metals were ranked higher than other substances. Pentachlorophenol, phenol, dieldrin, and methyl tert-butyl ether were ranked the highest among chlorinated compounds, aromatic compounds, pesticides, and others, respectively. The priority substance list generated from CROSS will be used in selecting substances for possible inclusion in the Korean soil quality standard expansion; it will also provide important information for designing a soil-environment management scheme.

  2. The effects of freezing and thawing on the aqueous availability of creosote contamination in soil

    SciTech Connect

    Bevel, A.; Hrudey, S.; Dudas, M.; Sego, D.

    1996-11-01

    A variety of methods have been tested in attempts to remediate contaminated sites. Fine-grained soils are extremely problematic to remediate, due to the high adsorption capacity of the fine soil particles and the trapping effect of soil particle micropores. It is well documented that freezing of soil causes particle restructuring and reorganization, with different pore structures found after freezing. Some factors affecting restructuring include soil moisture content, freezing rate, freezing end-point temperature, and number of freezing cycles. This poster presents an experiment that determines if freezing creosote contaminated soil improves accessibility of the creosote, by measuring aqueous phase contaminant dissolution. This method was selected since water is the most common solvent in naturally occurring systems, and water represents a worst-case scenario since many contaminants have low aqueous solubilities. Freezing is carried out under controlled laboratory conditions. Variables examined include moisture content, freezing rate, and soil contamination level. If contaminant availability is increased through soil freezing, remediation becomes an easier task in fine grained soils.

  3. Biochar as possible long-term soil amendment for phytostabilisation of TE-contaminated soils.

    PubMed

    Bopp, Charlotte; Christl, Iso; Schulin, Rainer; Evangelou, Michael W H

    2016-09-01

    Soils contaminated by trace elements (TEs) pose a high risk to their surrounding areas as TEs can spread by wind and water erosion or leaching. A possible option to reduce TE transfer from these sites is phytostabilisation. It is a long-term and cost-effective rehabilitation strategy which aims at immobilising TEs within the soil by vegetation cover and amendment application. One possible amendment is biochar. It is charred organic matter which has been shown to immobilise metals due to its high surface area and alkaline pH. Doubts have been expressed about the longevity of this immobilising effect as it could dissipate once the carbonates in the biochar have dissolved. Therefore, in a pot experiment, we determined plant metal uptake by ryegrass (Lolium perenne) from three TE-contaminated soils treated with two biochars, which differed only in their pH (acidic, 2.80; alkaline, 9.33) and carbonate (0.17 and 7.3 %) content. Root biomass was increased by the application of the alkaline biochar due to the decrease in TE toxicity. Zinc and Cu bioavailability and plant uptake were equally reduced by both biochars, showing that surface area plays an important role in metal immobilisation. Biochar could serve as a long-term amendment for TE immobilisation even after its alkalinity effect has dissipated. PMID:27230149

  4. Biochar as possible long-term soil amendment for phytostabilisation of TE-contaminated soils.

    PubMed

    Bopp, Charlotte; Christl, Iso; Schulin, Rainer; Evangelou, Michael W H

    2016-09-01

    Soils contaminated by trace elements (TEs) pose a high risk to their surrounding areas as TEs can spread by wind and water erosion or leaching. A possible option to reduce TE transfer from these sites is phytostabilisation. It is a long-term and cost-effective rehabilitation strategy which aims at immobilising TEs within the soil by vegetation cover and amendment application. One possible amendment is biochar. It is charred organic matter which has been shown to immobilise metals due to its high surface area and alkaline pH. Doubts have been expressed about the longevity of this immobilising effect as it could dissipate once the carbonates in the biochar have dissolved. Therefore, in a pot experiment, we determined plant metal uptake by ryegrass (Lolium perenne) from three TE-contaminated soils treated with two biochars, which differed only in their pH (acidic, 2.80; alkaline, 9.33) and carbonate (0.17 and 7.3 %) content. Root biomass was increased by the application of the alkaline biochar due to the decrease in TE toxicity. Zinc and Cu bioavailability and plant uptake were equally reduced by both biochars, showing that surface area plays an important role in metal immobilisation. Biochar could serve as a long-term amendment for TE immobilisation even after its alkalinity effect has dissipated.

  5. Chemodynamics of heavy metals in long-term contaminated soils: metal speciation in soil solution.

    PubMed

    Kim, Kwon-Rae; Owens, Gary

    2009-01-01

    The concentration and speciation of heavy metals in soil solution isolated from long-term contaminated soils were investigated. The soil solution was extracted at 70% maximum water holding capacity (MWHC) after equilibration for 24 h. The free metal concentrations (Cd2+, CU2+, Pb2+, and Zn2+) in soil solution were determined using the Donnan membrane technique (DMT). Initially the DMT was validated using artificial solutions where the percentage of free metal ions were significantly correlated with the percentages predicted using MINTEQA2. However, there was a significant difference between the absolute free ion concentrations predicted by MINTEQA2 and the values determined by the DMT. This was due to the significant metal adsorption onto the cation exchange membrane used in the DMT with 20%, 28%, 44%, and 8% mass loss of the initial total concentration of Cd, Cu, Pb, and Zn in solution, respectively. This could result in a significant error in the determination of free metal ions when using DMT if no allowance for membrane cation adsorption was made. Relative to the total soluble metal concentrations the amounts of free Cd2+ (3%-52%) and Zn2+ (11%-72%) in soil solutions were generally higher than those of Cu2+ (0.2%-30%) and Pb2+ (0.6%-10%). Among the key soil solution properties, dissolved heavy metal concentrations were the most significant factor governing free metal ion concentrations. Soil solution pH showed only a weak relationship with free metal ion partitioning coefficients (K(p)) and dissolved organic carbon did not show any significant influence on K(p). PMID:20108686

  6. Soil water and vegetation management for cleanup of selenium contaminated soils

    SciTech Connect

    Not Available

    1989-05-01

    Over the past year scientists have initiatived a new effort aimed at developing a soil water and vegetation management plan for Kesterson Reservoir. The plan is intended to result in a gradual depletion of the inventory of soluble selenium at the Reservoir through a combination agriculturally oriented practices that enhance dissipation of selenium from near surface soils. Agriculturally oriented processes that will contribute to depletion include microbial volatilization from the soils, direct volatilization by living plants, decomposition and volatilization of selenium-bearing vegetation, harvest and removal of seleniferous vegetation, and leaching. The benefits of using this integrated approach are that (1) no single mechanism needs to be relied upon to detoxify the soils, (2) a stable plant community can be established during this period so that impacts to wildlife can be more easily evaluated and controlled, (3) cleanup and management of the site can be carried out in a cost-effective manner. The management plan is also intended to facilitate control over wildlife exposure to selenium contaminated biota by creating a well managed environment. The majority of research associated with this new effort is being carried out at a 200 m by 50 m test plot in Pond 7. A two-line irrigation system , providing local groundwater as an irrigation supply, has been installed. Through an intensive program of soil water sampling, soil gas sampling, vegetation sampling, groundwater monitoring, and soil moisture monitoring, the mass balance for selenium under irrigated conditions is being evaluated. These studies, in conjunction with supplementary laboratory experiments will provide the information needed to develop an optimal management plan for the site. 23 refs., 38 figs., 10 tabs.

  7. Effects of metal-contaminated forest soils from the Canadian shield to terrestrial organisms.

    PubMed

    Feisthauer, Natalie C; Stephenson, Gladys L; Princz, Juliska I; Scroggins, Richard P

    2006-03-01

    The effects of elevated metal concentrations in forest soils on terrestrial organisms were investigated by determining the toxicity of six site soils from northern Ontario and Quebec, Canada, using a battery of terrestrial toxicity tests. Soils were collected from three sites on each of two transects established downwind of nickel (Sudbury, ON, Canada) and copper (Rouyn-Noranda, PQ, Canada) smelting operations. Site soils were diluted to determine if toxicity estimates for the most-contaminated site soils could be quantified as a percent of site soil. Rouyn-Noranda soils were toxic following acute exposure (14 d) to plants, but not to invertebrates (7 d for collembola and 14 d for earthworms). However, Rouyn-Noranda soils were toxic to all species following chronic exposure (21, 35, and 63 d for plants, collembola, and earthworms, respectively). The toxicity of the Rouyn-Noranda site soils did not correspond to the gradient of metal concentrations in soil. Metal-contaminated Sudbury soils were toxic to plants but not to invertebrates, following acute exposure. Chronic exposure to Sudbury soils caused adverse effects to plant growth and invertebrate survival and reproduction. The toxicity of Sudbury soils corresponded to the metal concentration gradient, with one exception: The reference soil collected in October was toxic to collembola following acute and chronic exposure. This study evaluated the applicability of the new Environment Canada terrestrial toxicity test methods, developed using agricultural soils, to forest soils and also provided useful data to assess the ecological risk associated with mixtures of metals in soil.

  8. Approach to study of heavy metal contamination effect on biological activity in Mediterranean Spanish soils

    NASA Astrophysics Data System (ADS)

    Roca-Pérez, L.; Gil, C.; Mormeneo, S.; Abad, M.; Cervera, M.; González, A.; Boluda, R.

    2009-04-01

    Heavy metal contaminated soils results in various negative environmental effects such as a decrease in biological diversity, decline crop productivity or human exposure to toxic elements in the others. The influence of heavy metal contamination in Spanish Mediterranean soils on its biological activity was studied. Non-polluted soils and heavy metal contaminated soils were sampled from different sites affected by several industrial activities. Soil characteristics, heavy metals (As, Ba, Cd, Cr, Cu, Ni, Pb, Se, Sr, Zn and V), soil organic matter, microorganism numbers, biomass microbial carbon, soil respiration and dehydrogenase activity were determined. Except to a rice farming soil, the results indicate that soils with high concentrations of As, Cd, Cr, Cu, Ni, Pb, Sr and Zn showed low soil respiration, biomass carbon and dehydrogenase activity with respect non-polluted soils with similar characteristics. Our results provide evidence that these parameters are good approach to study of heavy metal contamination effect on biological activity in Mediterranean soils. We would like to thank Spanish government-MICINN for funding and support (MICINN, project CGL2006-09776).

  9. APPLICATION OF PLANT AND EARTHWORM BIOASSAYS TO EVALUATE REMEDIATION OF A LEAD-CONTAMINATED SOIL

    EPA Science Inventory

    Earthworm acute toxicity, plant seed germination/root elongation (SG/RE) and plant genotoxicity bioassays were employed to evaluate the remediation of a lead-contaminated soil. The remediation involved removal of heavy metals by a soil washing/soil leaching treatment process. A p...

  10. FORMATION OF CHLOROPYROMORPHITE IN A LEAD-CONTAMINATED SOIL AMENDED WITH HYDROXYAPATITE

    EPA Science Inventory

    To evaluate conversion of soil Pb to pyromorphite, a Pb contaminated soil collected adjacent to a historical smelter was reacted with hydroxyapatite in a traditional incubation experiment and in a dialysis system in which the soil and hydroxyapatite solids were separated by a dia...

  11. [Field scale demonstration of fungi-bacteria augmented remediation of petroleum-contaminated soil].

    PubMed

    Han, Hui-long; Chen, Zhen; Yang, Jian-min; Miao, Chang-chun; Zhang, Kun; Jin, Wen-biao; Liu, Zheng

    2008-02-01

    Pilot demonstration of the fungal-bacterial augmented in situ remediation of petroleum contaminated soil was carried out in Zhongyuan Oilfield, Henan, using artificially prepared soil, newly and aged contaminated soil as sample, respectively. For the first run of the experiment started from Nov. 5, 2004 and lasted for 122 days, the removal of contaminate was 61.0%, 48.3% and 38.3% for diesel, lube and crude oil, respectively. For the second run started from May 18, 2005 and lasted for 161 days, the removal of TPH was 75% for the artificially contaminated soil sample while 46.0% and 56.6% for the fresh and aged contaminated soil. The removal of high concentration salt was involved in the remediation of the freshly and aged contaminated soil. The changes of the petroleum composition was monitored during the remediation process, which confirmed the effective degradation of alkanes, aromatic hydrocarbons and non-hydrocarbon compounds by the fungi-bacteria consortia, as compared to that obtained without the inoculation of the consortia. To further demonstrate the remediation, wheat was planted in above reclaimed soil. While wheat production in the reclaimed artificially contaminated soil yielded nearly as much as that obtained in the normal farmland, the output of wheat in the reclaimed refresh and aged contaminated soil was 57.2% and 70.3% of the averaged output of the normal farmland. The above results further confirmed the workability of fungal-bacterial augmented in situ remediation of petroleum contaminated soil and its application potential as well.

  12. [Dynamic changes in functional genes for nitrogen bioremediation of petroleum-contaminated soil cycle during].

    PubMed

    Wu, Bin-Bin; Lu, Dian-Nan; Liu, Zheng

    2012-06-01

    Microorganisms in nitrogen cycle serve as an important part of the ecological function of soil. The aim of this research was to monitor the abundance of nitrogen-fixing, denitrifying and nitrifying bacteria during bioaugmentation of petroleum-contaminated soil using real-time polymerase chain reaction (real-time PCR) of nifH, narG and amoA genes which encode the key enzymes in nitrogen fixation, nitrification and ammoniation respectively. Three different kinds of soils, which are petroleum-contaminated soil, normal soil, and remediated soil, were monitored. It was shown that the amounts of functional microorganisms in petroleum-contaminated soil were far less than those in normal soil, while the amounts in remediated soil and normal soil were comparable. Results of this experiment demonstrate that nitrogen circular functional bacteria are inhibited in petroleum-contaminated soil and can be recovered through bioremediation. Furthermore, copies of the three functional genes as well as total petroleum hydrocarbons (TPH) for soils with six different treatments were monitored. Among all treatments, the one, into which both E. cloacae as an inoculant and wheat straw as an additive were added, obtained the maximum copies of 2.68 x 10(6), 1.71 x 10(6) and 8.54 x 10(4) per gram dry soil for nifH, narG and amoA genes respectively, companying with the highest degradation rate (48% in 40 days) of TPH. The recovery of functional genes and removal of TPH were better in soil inoculated with E cloacae and C echinulata collectively than soil inoculated with E cloacae only. All above results suggest that the nitrogen circular functional genes could be applied to monitor and assess the bioremediation of petroleum-contaminated soil.

  13. Assessment of Soil-Gas and Soil Contamination at the Former Military Police Range, Fort Gordon, Georgia, 2009-2010

    USGS Publications Warehouse

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

    2011-01-01

    Soil gas and soil were assessed for organic and inorganic contaminants at the former military police range at Fort Gordon, Georgia, from May to September 2010. The assessment evaluated organic contaminants in soil-gas samplers and inorganic contaminants in soil samples. This assessment was conducted to provide environmental contamination data to Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. Soil-gas samplers deployed and collected from May 20 to 24, 2010, identified masses above method detection level for total petroleum hydrocarbons, gasoline-related and diesel-related compounds, and chloroform. Most of these detections were in the southwestern quarter of the study area and adjacent to the road on the eastern boundary of the site. Nine of the 11 chloroform detections were in the southern half of the study area. One soil-gas sampler deployed adjacent to the road on the southern boundary of the site detected a mass of tetrachloroethene greater than, but close to, the method detection level of 0.02 microgram. For soil-gas samplers deployed and collected from September 15 to 22, 2010, none of the selected organic compounds classified as chemical agents and explosives were detected above method detection levels. Inorganic concentrations in the five soil samples collected at the site did not exceed the U.S. Environmental Protection Agency regional screening levels for industrial soil and were at or below background levels for similar rocks and strata in South Carolina.

  14. Assessment of Soil Moisture and Fixatives Performance in Controlling Wind Erosion of Contaminated Soil at the Hanford Site

    SciTech Connect

    Lagos, L.E.; Gudavalli, R.K.

    2008-07-01

    During the remediation of burial grounds at the US Department of Energy's (DOE's) Hanford Site in Washington State, the dispersion of contaminated soil particles and dust is an issue that is faced by site workers on a daily basis. This contamination issue is even more of a concern when one takes into account the semi-arid characteristics of the region where the site is located. To mitigate this problem, workers at the site use a variety of engineered methods to minimize the dispersion of contaminated soil and dust particles. Once such methods is the use of water and/or suppression agents (fixatives) that stabilizes the soil prior to soil excavation, segregation, and removal activities. A primary contributor to the dispersion of contaminated soil and dust is wind soil erosion. The erosion process occurs when the wind speed exceeds a certain threshold value (threshold shear velocity), which depends on a number of factors including wind force loading, particle size, surface soil moisture, and the geometry of the soil. Thus under these circumstances the mobility of contaminated soil and generation and dispersion of particulate matter are significantly influenced by these parameters. Wind tunnel experiments were conducted at the Florida International University's Applied Research Center (FIU-ARC) to evaluate the effectiveness of three commercially available fixatives in controlling the mobility of soil particles on soil mounds when exposed to varying wind forces. The fixatives tested included: (1) a calcium chloride solution; (2) a petroleum hydrocarbon emulsion; and 3) a synthetic organic. As an initial step, approximately 500 lbs of uncontaminated soil was obtained from the Hanford Reservation in Washington State. Soil samples were placed in an open-loop, low speed wind tunnel and exposed to wind forces ranging from 10 to 30 miles per hour (mph). Wind erosion controlling capabilities of commercially available fixatives and soil moisture were tested at a laboratory

  15. Effects of Soil Oxygen Conditions and Soil pH on Remediation of DDT-contaminated Soil by Laccase from White Rot Fungi

    PubMed Central

    Zhao, Yuechun; Yi, Xiaoyun

    2010-01-01

    High residues of DDT in agricultural soils are of concern because they present serious threats to food security and human health. This article focuses on remediation of DDT-contaminated soil using laccase under different soil oxygen and soil pH conditions. The laboratory experiment results showed significant effects of soil oxygen conditions and soil pH on remediation of DDT-contaminated soil by laccase at the end of a 25-d incubation period. This study found the positive correlation between the concentration of oxygen in soil and the degradation of DDT by laccase. The residue of DDTs in soil under the atmosphere of oxygen decreased by 28.1% compared with the atmosphere of nitrogen at the end of the incubation with laccase. A similar pattern was observed in the remediation of DDT-contaminated soil by laccase under different flooding conditions, the higher the concentrations of oxygen in soil, the lower the residues of four DDT components and DDTs in soils. The residue of DDTs in the nonflooding soil declined by 16.7% compared to the flooded soil at the end of the incubation. The residues of DDTs in soils treated with laccase were lower in the pH range 2.5–4.5. PMID:20617049

  16. Effects of soil oxygen conditions and soil pH on remediation of DDT-contaminated soil by laccase from white rot fungi.

    PubMed

    Zhao, Yuechun; Yi, Xiaoyun

    2010-04-01

    High residues of DDT in agricultural soils are of concern because they present serious threats to food security and human health. This article focuses on remediation of DDT-contaminated soil using laccase under different soil oxygen and soil pH conditions. The laboratory experiment results showed significant effects of soil oxygen conditions and soil pH on remediation of DDT-contaminated soil by laccase at the end of a 25-d incubation period. This study found the positive correlation between the concentration of oxygen in soil and the degradation of DDT by laccase. The residue of DDTs in soil under the atmosphere of oxygen decreased by 28.1% compared with the atmosphere of nitrogen at the end of the incubation with laccase. A similar pattern was observed in the remediation of DDT-contaminated soil by laccase under different flooding conditions, the higher the concentrations of oxygen in soil, the lower the residues of four DDT components and DDTs in soils. The residue of DDTs in the nonflooding soil declined by 16.7% compared to the flooded soil at the end of the incubation. The residues of DDTs in soils treated with laccase were lower in the pH range 2.5-4.5. PMID:20617049

  17. Phytoremediation of uranium-contaminated soils: Role of organic acids in triggering uranium hyperaccumulation in plants

    SciTech Connect

    Huang, J.W.; Blaylock, M.J.; Kapulnik, Y.; Ensley, B.D.

    1998-07-01

    Uranium phytoextraction, the use of plants to extract U from contaminated soils, is an emerging technology. The authors report on the development of this technology for the cleanup of U-contaminated soils. In this research, they investigated the effects of various soil amendments on U desorption from soil to soil solution, studied the physiological characteristics of U uptake and accumulation in plants, and developed techniques to trigger U hyperaccumulation in plants. A key to the success of U phytoextraction is to increase soil U availability to plants. The authors have found that some organic acids can be added to soils to increase U desorption from soil to soil solution and to trigger a rapid U accumulation in plants. Of the organic acids (acetic acid, citric acid, and malic acid) tested, citric acid was the most effective in enhancing U accumulation in plants. Shoot U concentrations of Brassica juncea and Brassica chinensis grown in a U-contaminated soil increased from less than 5 mg kg{sup {minus}1} to more than 5,000 mg kg{sup {minus}1} in citric acid-treated soils. To their knowledge, this is the highest shoot U concentration reported for plants grown on U-contaminated soils. Using this U hyperaccumulation technique, they are now able to increase U accumulation in shoots of selected plant species grown in two U-contaminated soils by more than 1,000-fold within a few days. The results suggest that U phytoextraction may provide an environmentally friendly alternative for the cleanup of U-contaminated soils.

  18. Radionuclide Activities in Contaminated Soils: Effects of Sampling Bias on Remediation of Coarse-Grained Soils in Hanford Formation

    SciTech Connect

    Mattigod, Shas V.; Martin, Wayne J.

    2001-08-28

    Only a limited set of particle size-contaminant concentration data is available for soils from the Hanford Site. These data are based on bench-scale tests on single soil samples from one waste site each in operable units 100-BC-1, 100-DR-1, and 100-FR-1, and three samples from the North Pond 300-FF-1 operable unit. The objective of this study was to 1) examine available particle size-contaminant of concern activity and concentration data for 100 and 300 Area soils, 2) assess the effects of sampling bias, 3) suggest sampling protocols, and 4) formulate a method to determine the contaminant of concern activities and concentrations of the whole soil based on the measurements conducted on a finer size fraction of the whole soil.

  19. Removal of uranium from uranium-contaminated soils -- Phase 1: Bench-scale testing. Uranium in Soils Integrated Demonstration

    SciTech Connect

    Francis, C. W.

    1993-09-01

    To address the management of uranium-contaminated soils at Fernald and other DOE sites, the DOE Office of Technology Development formed the Uranium in Soils Integrated Demonstration (USID) program. The USID has five major tasks. These include the development and demonstration of technologies that are able to (1) characterize the uranium in soil, (2) decontaminate or remove uranium from the soil, (3) treat the soil and dispose of any waste, (4) establish performance assessments, and (5) meet necessary state and federal regulations. This report deals with soil decontamination or removal of uranium from contaminated soils. The report was compiled by the USID task group that addresses soil decontamination; includes data from projects under the management of four DOE facilities [Argonne National Laboratory (ANL), Los Alamos National Laboratory (LANL), Oak Ridge National Laboratory (ORNL), and the Savannah River Plant (SRP)]; and consists of four separate reports written by staff at these facilities. The fundamental goal of the soil decontamination task group has been the selective extraction/leaching or removal of uranium from soil faster, cheaper, and safer than current conventional technologies. The objective is to selectively remove uranium from soil without seriously degrading the soil`s physicochemical characteristics or generating waste forms that are difficult to manage and/or dispose of. Emphasis in research was placed more strongly on chemical extraction techniques than physical extraction techniques.

  20. Carbon nanomaterials in clean and contaminated soils: environmental implications and applications

    NASA Astrophysics Data System (ADS)

    Riding, M. J.; Martin, F. L.; Jones, K. C.; Semple, K. T.

    2014-06-01

    The exceptional sorptive ability of carbon nanomaterials (CNMs) for hydrophobic organic contaminants (HOCs) is driven by their characteristically large reactive surface areas and highly hydrophobic nature. Given these properties, it is possible for CNMs to impact on the persistence, mobility and bioavailability of contaminants within soils, either favourably through sorption and sequestration, hence reducing their bioavailability, or unfavourably through increasing contaminant dispersal. This review considers the complex and dynamic nature of both soil and CNM physicochemical properties to determine their fate and behaviour, together with their interaction with contaminants and the soil micro-flora. It is argued that assessment of CNMs within soil should be conducted on a case-by-case basis, and further work to assess the long-term stability of sorbed contaminants and the toxicity of CNMs is required before their sorptive abilities can be applied to remedy environmental issues.

  1. Carbon nanomaterials in clean and contaminated soils: environmental implications and applications

    NASA Astrophysics Data System (ADS)

    Riding, M. J.; Martin, F. L.; Jones, K. C.; Semple, K. T.

    2015-01-01

    The exceptional sorptive ability of carbon nanomaterials (CNMs) for hydrophobic organic contaminants (HOCs) is driven by their characteristically large reactive surface areas and highly hydrophobic nature. Given these properties, it is possible for CNMs to impact on the persistence, mobility and bioavailability of contaminants within soils, either favourably through sorption and sequestration, hence reducing their bioavailability, or unfavourably through increasing contaminant dispersal. This review considers the complex and dynamic nature of both soil and CNM physicochemical properties to determine their fate and behaviour, together with their interaction with contaminants and the soil microflora. It is argued that assessment of CNMs within soil should be conducted on a case-by-case basis and further work to assess the long-term stability and toxicity of sorbed contaminants, as well as the toxicity of CNMs themselves, is required before their sorptive abilities can be applied to remedy environmental issues.

  2. Methodology for setting risk-based concentrations of contaminants in soil and groundwater and application to a model contaminated site.

    PubMed

    Fujinaga, Aiichiro; Uchiyama, Iwao; Morisawa, Shinsuke; Yoneda, Minoru; Sasamoto, Yuzuru

    2012-01-01

    In Japan, environmental standards for contaminants in groundwater and in leachate from soil are set with the assumption that they are used for drinking water over a human lifetime. Where there is neither a well nor groundwater used for drinking, the standard is thus too severe. Therefore, remediation based on these standards incurs excessive effort and cost. In contrast, the environmental-assessment procedure used in the United States and the Netherlands considers the site conditions (land use, existing wells, etc.); however, a risk assessment is required for each site. Therefore, this study proposes a new framework for judging contamination in Japan by considering the merits of the environmental standards used and a method for risk assessment. The framework involves setting risk-based concentrations that are attainable remediation goals for contaminants in soil and groundwater. The framework was then applied to a model contaminated site for risk management, and the results are discussed regarding the effectiveness and applicability of the new methodology.

  3. Cleaning contaminated soil using electrical heating and air stripping

    SciTech Connect

    Buettner, H.M.; Daily, W.D.

    1995-08-01

    In the summer of 1992, a proof-of-concept demonstration of direct electrical heating and air stripping was conducted for enhancing the removal of a volatile organic contaminant, trichloroethylene (TCSE), from soil. Six electrodes were buried in shallow boreholes so that a target region 6.1 m in diameter and 3.05 m in height was heated by ohmic dissipation of power-line-frequency electrical currents supplied by a diesel generator. Air stripping of TCE contamination from the same region was accomplished from a single well at the center of the heated volume. The electrical energy used during the demonstration was 3.46 {times} 10{sup 10} J (9,600 kW {center_dot} h), and the temperature of the extracted air rose from 16 C to 38 C. An energy balance shows that input energy is consistent with the temperature rise in the target volume and the amount of water vaporized at the electrodes. Prior to heating, the TCE concentration in the vapor decreased from about 80 parts per million by volume (ppm{sub v}) to around 60 ppm{sub v}. As soon as electrical heating started, TCE concentrations began to increase. Some concentration data were lost shortly after electrical heating began. After the system was repaired, the TCE concentration fell rapidly from about 140 ppm{sub v} to 5 ppm{sub v} over a period of about 25 days. A simple two-dimensional model for calculation of heating rates is also presented and verified experimentally. Finally some of the operation and safety issues associated with electrical heating are discussed.

  4. Health risk-based assessment and management of heavy metals-contaminated soil sites in Taiwan.

    PubMed

    Lai, Hung-Yu; Hseu, Zeng-Yei; Chen, Ting-Chien; Chen, Bo-Ching; Guo, Horng-Yuh; Chen, Zueng-Sang

    2010-10-01

    Risk-based assessment is a way to evaluate the potential hazards of contaminated sites and is based on considering linkages between pollution sources, pathways, and receptors. These linkages can be broken by source reduction, pathway management, and modifying exposure of the receptors. In Taiwan, the Soil and Groundwater Pollution Remediation Act (SGWPR Act) uses one target regulation to evaluate the contamination status of soil and groundwater pollution. More than 600 sites contaminated with heavy metals (HMs) have been remediated and the costs of this process are always high. Besides using soil remediation techniques to remove contaminants from these sites, the selection of possible remediation methods to obtain rapid risk reduction is permissible and of increasing interest. This paper discusses previous soil remediation techniques applied to different sites in Taiwan and also clarified the differences of risk assessment before and after soil remediation obtained by applying different risk assessment models. This paper also includes many case studies on: (1) food safety risk assessment for brown rice growing in a HMs-contaminated site; (2) a tiered approach to health risk assessment for a contaminated site; (3) risk assessment for phytoremediation techniques applied in HMs-contaminated sites; and (4) soil remediation cost analysis for contaminated sites in Taiwan.

  5. Characterization and Low-Cost Remediation of Soils Contaminated by Timbers in Community Gardens.

    PubMed

    Heiger-Bernays, W; Fraser, A; Burns, V; Diskin, K; Pierotti, D; Merchant-Borna, K; McClean, M; Brabander, D; Hynes, H P

    2009-01-01

    Urban community gardens worldwide provide significant health benefits to those gardening and consuming fresh produce from them. Urban gardens are most often placed in locations and on land in which soil contaminants reflect past practices and often contain elevated levels of metals and organic contaminants. Garden plot dividers made from either railroad ties or chromated copper arsenate (CCA) pressure treated lumber contribute to the soil contamination and provide a continuous source of contaminants. Elevated levels of polycyclic aromatic hydrocarbons (PAHs) derived from railroad ties and arsenic from CCA pressure treated lumber are present in the gardens studied. Using a representative garden, we 1) determined the nature and extent of urban community garden soil contaminated with PAHs and arsenic by garden timbers; 2) designed a remediation plan, based on our sampling results, with our community partner guided by public health criteria, local regulation, affordability, and replicability; 3) determined the safety and advisability of adding city compost to Boston community gardens as a soil amendment; and 4) made recommendations for community gardeners regarding healthful gardening practices. This is the first study of its kind that looks at contaminants other than lead in urban garden soil and that evaluates the effect on select soil contaminants of adding city compost to community garden soil. PMID:21804925

  6. Characterization and Low-Cost Remediation of Soils Contaminated by Timbers in Community Gardens

    PubMed Central

    Heiger-Bernays, W.; Fraser, A.; Burns, V.; Diskin, K.; Pierotti, D.; Merchant-Borna, K.; McClean, M.; Brabander, D.; Hynes, H. P.

    2011-01-01

    Urban community gardens worldwide provide significant health benefits to those gardening and consuming fresh produce from them. Urban gardens are most often placed in locations and on land in which soil contaminants reflect past practices and often contain elevated levels of metals and organic contaminants. Garden plot dividers made from either railroad ties or chromated copper arsenate (CCA) pressure treated lumber contribute to the soil contamination and provide a continuous source of contaminants. Elevated levels of polycyclic aromatic hydrocarbons (PAHs) derived from railroad ties and arsenic from CCA pressure treated lumber are present in the gardens studied. Using a representative garden, we 1) determined the nature and extent of urban community garden soil contaminated with PAHs and arsenic by garden timbers; 2) designed a remediation plan, based on our sampling results, with our community partner guided by public health criteria, local regulation, affordability, and replicability; 3) determined the safety and advisability of adding city compost to Boston community gardens as a soil amendment; and 4) made recommendations for community gardeners regarding healthful gardening practices. This is the first study of its kind that looks at contaminants other than lead in urban garden soil and that evaluates the effect on select soil contaminants of adding city compost to community garden soil. PMID:21804925

  7. Soil biotransformation of thiodiglycol, the hydrolysis product of mustard gas: understanding the factors governing remediation of mustard gas contaminated soil.

    PubMed

    Li, Hong; Muir, Robert; McFarlane, Neil R; Soilleux, Richard J; Yu, Xiaohong; Thompson, Ian P; Jackman, Simon A

    2013-02-01

    Thiodiglycol (TDG) is both the precursor for chemical synthesis of mustard gas and the product of mustard gas hydrolysis. TDG can also react with intermediates of mustard gas degradation to form more toxic and/or persistent aggregates, or reverse the pathway of mustard gas degradation. The persistence of TDG have been observed in soils and in the groundwater at sites contaminated by mustard gas 60 years ago. The biotransformation of TDG has been demonstrated in three soils not previously exposed to the chemical. TDG biotransformation occurred via the oxidative pathway with an optimum rate at pH 8.25. In contrast with bacteria isolated from historically contaminated soil, which could degrade TDG individually, a consortium of three bacterial strains isolated from the soil never contaminated by mustard gas was able to grow on TDG in minimal medium and in hydrolysate derived from an historical mustard gas bomb. Exposure to TDG had little impacts on the soil microbial physiology or on community structure. Therefore, the persistency of TDG in soils historically contaminated by mustard gas might be attributed to the toxicity of mustard gas to microorganisms and the impact to soil chemistry during the hydrolysis. TDG biodegradation may form part of a remediation strategy for mustard gas contaminated sites, and may be enhanced by pH adjustment and aeration. PMID:22752796

  8. Soil biotransformation of thiodiglycol, the hydrolysis product of mustard gas: understanding the factors governing remediation of mustard gas contaminated soil.

    PubMed

    Li, Hong; Muir, Robert; McFarlane, Neil R; Soilleux, Richard J; Yu, Xiaohong; Thompson, Ian P; Jackman, Simon A

    2013-02-01

    Thiodiglycol (TDG) is both the precursor for chemical synthesis of mustard gas and the product of mustard gas hydrolysis. TDG can also react with intermediates of mustard gas degradation to form more toxic and/or persistent aggregates, or reverse the pathway of mustard gas degradation. The persistence of TDG have been observed in soils and in the groundwater at sites contaminated by mustard gas 60 years ago. The biotransformation of TDG has been demonstrated in three soils not previously exposed to the chemical. TDG biotransformation occurred via the oxidative pathway with an optimum rate at pH 8.25. In contrast with bacteria isolated from historically contaminated soil, which could degrade TDG individually, a consortium of three bacterial strains isolated from the soil never contaminated by mustard gas was able to grow on TDG in minimal medium and in hydrolysate derived from an historical mustard gas bomb. Exposure to TDG had little impacts on the soil microbial physiology or on community structure. Therefore, the persistency of TDG in soils historically contaminated by mustard gas might be attributed to the toxicity of mustard gas to microorganisms and the impact to soil chemistry during the hydrolysis. TDG biodegradation may form part of a remediation strategy for mustard gas contaminated sites, and may be enhanced by pH adjustment and aeration.

  9. Reducing the bioavailability of cadmium in contaminated soil by dithiocarbamate chitosan as a new remediation.

    PubMed

    Yin, Zheng; Cao, Jingjing; Li, Zhen; Qiu, Dong

    2015-07-01

    Dithiocarbamate chitosan (DTC-CTS) was used as a new amendment for remediation of cadmium (Cd)-contaminated soils to reduce the Cd bioavailability. Arabidopsis thaliana was chosen as a model plant to evaluate its efficiency. It was found that DTC-CTS could effectively improve the growth of A. thaliana. The amount of Cd up-taken by A. thaliana could be decreased by as much as 50% compared with that grown in untreated Cd-contaminated soil samples. The chlorophyll content and the aerial biomass of Arabidopsis also increased substantially and eventually returned to a level comparable to plants grown in non-contaminated soils, with the addition of DTC-CTS. These findings suggested that DTC-CTS amendment could be effective in immobilizing Cd and mitigating its accumulation in plants grown in Cd-contaminated soils, with potential application as an in situ remediation of Cd-polluted soils.

  10. Characterization and solubility measurements of uranium-contaminated soils to support risk assessment.

    PubMed

    Elless, M P; Armstrong, A Q; Lee, S Y

    1997-05-01

    Remediation of uranium-contaminated soils is considered a high priority by the U.S. Department of Energy because these soils, if left untreated, represent a hazard to the environment and human health. Because the risk to human health is a function of the solubility of uranium in the soils, the objectives of this work are to measure the uranium solubility of two contaminated soils, before and after remedial treatment, and determine the health risk associated with these soils. Two carbonate-rich, uranium-contaminated soils from the U.S. Department of Energy Fernald Environmental Management Project facility near Cincinnati, Ohio, as well as two nearby background soils were characterized and their uranium solubility measured in a 75-d solubility experiment using acid rain, groundwater, lung serum, and stomach acid simulants. Results show that the soluble uranium levels of each soil by each simulant are greatly influenced by their contamination source term. Risk calculations and biokinetic modeling based on the solubility data show that the risks from the soil ingestion and groundwater ingestion pathways are the predominant contributors to the total carcinogenic risk, whereas the risk from the soil inhalation pathway is the smallest contributor to this risk. However, kidney toxicity was the greater health concern of the Fernald Environmental Management Project soils, primarily from undiluted ingestion of the groundwater solution following contact with the contaminated soils. Sensitivity analyses indicate that uranium solubility is a key parameter in defining kidney toxicity; therefore, without proper consideration of the solubility of radionuclides/metals in untreated and treated soils, important factors may be overlooked which may result in soil cleanup goals or limits which are not protective of human health and the environment. We recommend that characterization and measurement of target radionuclides/metals solubilities should also be required by the regulatory

  11. Organic and inorganic diffuse contamination in urban soils: the case of Torino (Italy).

    PubMed

    Biasioli, Mattia; Ajmone-Marsan, Franco

    2007-08-01

    Soils in urban parks are useful tracers of diffuse contamination and could represent a potential health risk for citizens. Soils in the parks of Torino, Italy, were sampled and analysed for a broad range of organic and inorganic contaminants. Concentrations of potentially toxic elements, PAHs, PCBs and polychlorinated dibenzo-p-dioxins and dibenzofurans were often above national legislation limits, and higher than surrounding rural areas or than other cities. Mean concentrations were 233 mg kg(-1) for Cr, 164 mg kg(-1) for Ni, 124 mg kg(-1) for Pb and 170 mg kg(-1) for Zn. Other inorganic contaminants such as Cd, As, and Hg showed high concentrations in some soils. Organic contaminants were also found to be enriched in the sampled parks (e.g. maximum concentrations of PCDDs/DFs and PCBs were 12.6 ng kg(-1) and 0.310 mg kg(-1), respectively). Data from this study reveal an important enrichment of parks for some contaminants, reflecting the intensity of phenomena of diffuse contamination. Historical parks presented the highest degree of contamination, suggesting that the age of soils rather than their proximity to sources of emissions is a key factor in determining soil contamination. Data obtained in this study could be of help in the investigation and remediation practices of urban contaminated sites within large cities.

  12. Copper speciation and microbial activity in long-term contaminated soils.

    PubMed

    Dumestre, A; Sauvé, S; McBride, M; Baveye, P; Berthelin, J

    1999-02-01

    Most soil quality guidelines do not distinguish among the various forms of metals in soils; insoluble, nonreactive, and nonbioavailable forms are deemed as hazardous as highly soluble, reactive, and toxic forms. The objective of this study was to better understand the long-term effects of copper on microorganisms in relation to its chemical speciation in the soil environment. Carbon mineralization processes and the global structure of different microbial communities (fungi, eubacteria, actinomycetes) are still affected after more than 50 years of copper contamination in 20 soils sampled from two different agricultural sites. The microbial respiration lag period (LP) preceding the beginning of mineralization process increases with the level of soil copper contamination and is not significantly affected by other environmental factors such as soil pH and soil organic matter (SOM) content. The total copper concentration showed the best correlation with the LP when each site is considered separately. However, when considering the whole set of data, soil solution free Cu2+ activity (pCu2+) is the best predictor of Cu toxicity determined by LP (quite likely because pCu2+ integrates the soil physicochemical variability). The maximum mineralization rate (MMR), even if well correlated with the pCu2+, appears not to be a good biomonitor of copper contamination in soils since it is highly sensitive to soil characteristics such as SOM content. This study emphasizes the importance of the physicochemical properties of the environment on soil heavy metal toxicity and on soil toxicological measurements. These properties must be characterized in soil toxicological studies with respect to (1) their interactions with heavy metals, and (2) their direct impact on the selected biological test. The measurement of pCu2+ to characterize the level of soil contamination and of lag period as a bioindicator of metal effects in the soil are recognized as useful tools for the evaluation of the

  13. Soil application of biochar produced from biomass grown on trace element contaminated land.

    PubMed

    Evangelou, Michael W H; Brem, Anette; Ugolini, Fabio; Abiven, Samuel; Schulin, Rainer

    2014-12-15

    Trace element (TE) contamination of soils is a worldwide problem. However, although not considered safe anymore for food production without clean-up, many of these soils may still be used to produce biomass for non-food purposes such as biochar. Exploring the suitability of such biochar for the amendment of low-fertility soil, we investigated growth and metal accumulation of ryegrass (Lolium perenne, var. Calibra) as well as soil microbial abundance on a non-contaminated soil after amendment with biochar from birch (Betula pendula) wood produced on TE contaminated soil in comparison to a treatment with birch wood biochar originating from non-contaminated soil. Biochars were produced from both feedstocks by pyrolysis at two temperatures: 450 and 700 °C. During the pyrolysis, in contrast to Cu, Fe, Mg, K, Mn and P, the elements Cd, Pb, S and Na volatilized. The root biomass of the biochar treated plants was lower than that of the non-amended plants, while that of the shoot was higher. Plant shoot K and Zn concentrations were increased significantly by up to 7- and 3.3-fold respectively. For P, Mg, Mn, Fe and Cu no significant increase in shoot concentration could be detected. Neither the TE-contaminated biochar, nor the non-contaminated biochar had adverse effect on the bacterial community of the soil.

  14. Remediation of contaminated soils using supercritical fluid extraction: a review (1994-2004).

    PubMed

    Saldaña, M D A; Nagpal, V; Guigard, S E

    2005-09-01

    Considerable effort is being made to remediate soils contaminated with petroleum hydrocarbons, polyaromatic hydrocarbons, polychlorinated biphenyls, dioxins, heavy metals and other organic and inorganic compounds that have resulted from industrial activities, accidental spills and improper waste disposal practices. Current remediation technologies may be limited when treating certain types of contaminated soils and therefore new, efficient and cost effective technologies are being investigated. Supercritical fluid extraction is a potential remediation technology for contaminated soils. It is a simple, fast and selective solvent extraction process that uses a supercritical fluid as the solvent. A commonly used fluid is carbon dioxide at pressures and temperatures greater than 7.4 MPa and 31 degrees C, respectively. In supercritical fluid extraction, the extracted contaminants first dissolve into the supercritical solvent and then these contaminants are separated from the supercritical solvent via a simple change in pressure and temperature conditions or by using a separation process. This paper provides a review of supercritical fluid extraction and its application to the remediation of contaminated soils. This review focuses on the removal of organic contaminants (such as petroleum hydrocarbons, polyaromatic hydrocarbons, polychlorinated biphenyls and others) and inorganic contaminants (such as heavy metals and radioactive elements) from soils. Recent data (1994-2004) on the supercritical fluid extraction of spiked soils and field-contaminated soils were collected. The success of supercritical fluid extraction as a method for removing these contaminants from soils is highlighted and some of the future research needed to develop it as a commercial-scale economic remediation technology are discussed. PMID:16196410

  15. Time-dependent performance of soil mix technology stabilized/solidified contaminated site soils.

    PubMed

    Wang, Fei; Wang, Hailing; Al-Tabbaa, Abir

    2015-04-01

    This paper presents the strength and leaching performance of stabilized/solidified organic and inorganic contaminated site soil as a function of time and the effectiveness of modified clays applied in this project. Field trials of deep soil mixing application of stabilization/solidification (S/S) were performed at a site in Castleford in 2011. A number of binders and addictives were applied in this project including Portland cement (PC), ground granulated blastfurnace slag (GGBS), pulverised fuel ash (PFA), MgO and modified clays. Field trial samples were subjected to unconfined compressive strength (UCS), BS CN 12457 batch leaching test and the extraction of total organics at 28 days and 1.5 years after treatment. The results of UCS test show that the average strength values of mixes increased from 0-3250 kPa at 28 days to 250-4250 kPa at 1.5 years curing time. The BS EN 12457 leachate concentrations of all metals were well below their drinking water standard, except Ni in some mixes exceed its drinking water standard at 0.02 mg/l, suggesting that due to varied nature of binders, not all of them have the same efficiency in treating contaminated soil. The average leachate concentrations of total organics were in the range of 20-160 mg/l at 28 days after treatment and reduced to 18-140 mg/l at 1.5 years. In addition, organo clay (OC)/inorgano-organo clay (IOC) slurries used in this field trial were found to have a negative effect on the strength development, but were very effective in immobilizing heavy metals. The study also illustrates that the surfactants used to modify bentonite in this field trail were not suitable for the major organic pollutants exist in the site soil in this project. PMID:25603299

  16. Soil ventilation: Effects on microbial populations in gasoline-contaminated subsurface soils

    SciTech Connect

    Hickey, W.J.

    1995-07-01

    Short- and long-term effects of vapor extraction (VE) in an unsaturated subsurface soil and in situ biodegradation of gasoline were evaluated in a field study. Subsurface temperature, moisture, solid- and gas-phase contaminant levels, atmospheric gases, nutrient levels, and microbial population densities were measured during and after soil VE for 462 d. Microbial activity, based on in situ O{sub 2} consumption rates, measured 7 d after VE started averaged 3.8% O{sub 2} d{sup -1}; by Day 62 these rates dropped to 0.2% O{sub 2} d{sup -1}. Soil VE was stopped on Day 180 and about 70 d elapsed before renewed, low-level (0.05% O{sub 2} d{sup -1}) activity was detectable. Following a second round of VE, average O{sub 2} consumption rates increased to 0.11% O{sub 2} d{sup -1}. Microbial population densities did not consistently reflect activity changes measured by O{sub 2} consumption. Activity increases in the latter part of the study were not adequately accounted for by changes in subsurface moisture levels, temperature, or contaminant vapor concentrations. At the study`s completion, 400 kg of gasoline was volatilized from the soil and another 139 kg estimated to be biodegraded in situ. A two-phase process is proposed to account for the effects of VE on microbial activity. The initial phase is characterized by declining microbial activity levels in response to substrate reduction. Microbial activity slowly increases as a result of interactions between gasoline vapor concentrations and possibly changes in degradative activities of the microbial population. More work is needed to identify the gasoline constituents serving as substrates for microbial populations before and after ventilation. 31 refs., 8 figs., 5 tabs.

  17. Delineation of Hydrocarbon Contamination of Soils and Sediments With Environmental Magnetic Methods: Laboratory and Field Studies

    NASA Astrophysics Data System (ADS)

    Rijal, M. L.; Appel, E.; Porsch, K.; Kappler, A.; Blaha, U.; Petrovsky, E.

    2008-12-01

    Hydrocarbon contamination of soils and sediments is a worldwide environmental problem. The present research focuses on the study of magnetic properties of hydrocarbon contaminated soils and sediments using environmental magnetic methods both on field sites as well as in laboratory batch experiments. The main objectives of this research are i) to determine a possible application of magnetic proxies for the delineation of organic contamination in soils and sediments and ii) to examine the role of bacteria in changing soil magnetic properties after hydrocarbon contamination. A former oil field and a former military site which are heavily contaminated with hydrocarbons were studied. Additionally, three different types of natural clean soils were investigated in laboratory experiments by simulating hydrocarbon contamination in sterile and microbial active setups. Magnetic properties, soil properties, iron bioavailability, iron redox state and hydrocarbon content of samples were measured. Additionally, magnetic susceptibility (MS) was monitored weekly in laboratory batch set-ups during several months. Results from the field sites showed that there is an increase of MS and a good correlation between MS and hydrocarbon content. A weekly monitored MS result from the laboratory study clearly indicated~~10% change (increase as well as decrease) of initial MS of respective soils only in microbial active set-ups with saturation after a few weeks of experimental period. This depicts that there is a change of MS caused by microbial iron mineral transformation in presence of hydrocarbon contamination in soils. The results from the field study demonstrate that magnetic proxies can be used to localize hydrocarbon contamination. However, more field sites with hydrocarbon contaminated soils and sediments need to be investigated by using environmental magnetic methods for better understanding the factors driving such changes in magnetic properties.

  18. A partition-limited model for the plant uptake of organic contaminants from soil and water

    USGS Publications Warehouse

    Chiou, C.T.; Sheng, G.; Manes, M.

    2001-01-01

    In dealing with the passive transport of organic contaminants from soils to plants (including crops), a partition-limited model is proposed in which (i) the maximum (equilibrium) concentration of a contaminant in any location in the plant is determined by partition equilibrium with its concentration in the soil interstitial water, which in turn is determined essentially by the concentration in the soil organic matter (SOM) and (ii) the extent of approach to partition equilibrium, as measured by the ratio of the contaminant concentrations in plant water and soil interstitial water, ??pt (??? 1), depends on the transport rate of the contaminant in soil water into the plant and the volume of soil water solution that is required for the plant contaminant level to reach equilibrium with the external soil-water phase. Through reasonable estimates of plant organic-water compositions and of contaminant partition coefficients with various plant components, the model accounts for calculated values of ??pt in several published crop-contamination studies, including near-equilibrium values (i.e., ??pt ??? 1) for relatively water-soluble contaminants and lower values for much less soluble contaminants; the differences are attributed to the much higher partition coefficients of the less soluble compounds between plant lipids and plant water, which necessitates much larger volumes of the plant water transport for achieving the equilibrium capacities. The model analysis indicates that for plants with high water contents the plant-water phase acts as the major reservoir for highly water-soluble contaminants. By contrast, the lipid in a plant, even at small amounts, is usually the major reservoir for highly water-insoluble contaminants.

  19. [Response of soil microbial community to the bioremediation of soil contaminated with PAHs].

    PubMed

    Zhang, Jing; Lin, Xian-gui; Liu, Wei-wei; Yin, Rui

    2012-08-01

    The diversity of bacterial community in soil contaminated with polycyclic aromatic hydrocarbons (PAHs) was investigated during the plant-microbe remediation enhanced by biosurfactant rhamnolips (RH), using the polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method. The results showed that Shannon-Weaver diversity index was only 3.17 before bioremediation, and increased to 3.24-3.45 after bioremediation, in particular, highest value was found in the treatment of alfalfa (AL) inoculated with arbuscular mycorrhizal fungi (AM) and PAHs-degrading bacteria (DB) among all the treatments. The clustering analysis showed that the similarities of soil bacterial community of AL, AL + RH, AL + AM and AL + AM + RH were above 90%. At the same time, the similarity of AL + DB was much closer to those of the four treatments mentioned above. Additionally, when the bacterial communities of AL + DB + RH, AL + DB + AM and AL + DB + AM + RH were grouped together, the similarities of these three treatments were also higher than 80%. By sequence alignment, it was found that the predominant and characteristic bands in DGGE patterns were closely related with PAHs-degrading bacteria, such as Bacillus, Pseudomonas, Acidobacteria, Sphingmonas, Rhodopseudomonas, Firmicutes, and Methylocytaceae. Application of rhamnolipids in plant-microbe bioremediation not only improved the bioavailability of PAHs, but also had a simultaneous influence on the diversity of soil bacterial community, resulting in the efficient promotion of PAHs removal from soils.

  20. In vitro assessment of arsenic bioaccessibility in contaminated (anthropogenic and geogenic) soils.

    PubMed

    Juhasz, Albert L; Smith, Euan; Weber, John; Rees, Matthew; Rofe, Allan; Kuchel, Tim; Sansom, Lloyd; Naidu, Ravi

    2007-08-01

    Arsenic (As) bioaccessibility in contaminated soils (n=50) was assessed using the simplified bioaccessibility extraction test (SBET). Soils used in the study were collected from sites where As was used as an herbicide (railway corridor) or pesticide (cattle dip sites), from former gold mines and from highly mineralised locations containing geogenic As sources (gossans). In all but three soils, As bioaccessibility was less than 50% indicating that a significant proportion of the total As concentration may not be available for absorption in the gastrointestinal tract following incidental soil ingestion. When regression models were developed based on soil properties, the descriptive variables best able to describe As bioaccessibility in railway corridor, dip site and mine site soils were total As and total or dithionite-citrate extractable (free) iron (Fe). While As bioaccessibility could be predicted (r(2)=0.955, n=50) in these contaminated soils, As bioaccessibility for gossan soils was a poor fit using linear or multivariate regression analysis.

  1. Assessing the biological activity of oil-contaminated soddy-podzolic soils with different textures

    NASA Astrophysics Data System (ADS)

    Vershinin, A. A.; Petrov, A. M.; Akaikin, D. V.; Ignat'ev, Yu. A.

    2014-02-01

    The respiratory activity features in oil-contaminated soddy-podzolic soils of different textures have been studied. Unidirectional processes occur in contaminated loamy and loamy sandy soddy-podzolic soils; their intensities depend on the soil parameters. The mineralization rates of the oil products and the activity of the microflora in loamy soils exceed the corresponding parameters for loamy sandy soils. The long-term impact of oil and its transformation products results in more important disturbances of the microbial community in light soils. It has been shown that light soils containing 9% oil require longer time periods or more intensive remediation measures for the restoration of soil microbial cenoses disturbed by the pollutant.

  2. Possibilities of implementation of bioavailability methods for organic contaminants in the Dutch Soil Quality Assessment Framework.

    PubMed

    Brand, Ellen; Lijzen, Johannes; Peijnenburg, Willie; Swartjes, Frank

    2013-10-15

    In the Netherlands, risk assessment of contaminated soils is based on determining the total contaminant concentration. If this measured soil concentration exceeds the Soil Quality Standards (SQS) a higher tier risk evaluation must be performed. Experiences from the field have given rise to the perception that performing risk evaluations based on (measured) total concentrations may lead to an inaccurate assessment of the actual risks. Assuming that only the bioavailable fraction is capable of exerting adverse effects in the soil ecosystem, it is suggested, that by taking bioavailability into account in a (higher tier) risk evaluation, a more effect-based risk assessment can be performed. Bioavailability has been a subject of research for several decades. However up to now bioavailability has not been implemented in the Dutch Soil Quality Assessment Framework. First actions were taken in the Netherlands to determine whether the concept of bioavailability could be implemented in the risk assessment of contaminated soils and to find out how bioavailability can become part of the Dutch Soil Quality Assessment Framework. These actions have led to a concrete proposal for implementation of bioavailability methods in the risk assessment of organic contaminants in soils. This paper focuses on the chemical prediction of bioavailability for ecological risk assessment of contaminated soils.

  3. Microbial activity, arbuscular mycorrhizal fungi and inoculation of woody plants in lead contaminated soil

    PubMed Central

    Gattai, Graziella S.; Pereira, Sônia V.; Costa, Cynthia M. C.; Lima, Cláudia E. P.; Maia, Leonor C.

    2011-01-01

    The goals of this study were to evaluate the microbial activity, arbuscular mycorrhizal fungi and inoculation of woody plants (Caesalpinia ferrea, Mimosa tenuiflora and Erythrina velutina) in lead contaminated soil from the semi-arid region of northeastern of Brazil (Belo Jardim, Pernambuco). Dilutions were prepared by adding lead contaminated soil (270 mg Kg-1) to uncontaminated soil (37 mg Pb Kg soil-1) in the proportions of 7.5%, 15%, and 30% (v:v). The increase of lead contamination in the soil negatively influenced the amount of carbon in the microbial biomass of the samples from both the dry and rainy seasons and the metabolic quotient only differed between the collection seasons in the 30% contaminated soil. The average value of the acid phosphatase activity in the dry season was 2.3 times higher than observed during the rainy season. There was no significant difference in the number of glomerospores observed between soils and periods studied. The most probable number of infective propagules was reduced for both seasons due to the excess lead in soil. The mycorrhizal colonization rate was reduced for the three plant species assayed. The inoculation with arbuscular mycorrhizal fungi benefited the growth of Erythrina velutina in lead contaminated soil. PMID:24031701

  4. Feasibility of supercritical CO{sub 2} extraction as a remediation technology for Hanford contaminated soils

    SciTech Connect

    Moody, T.E.; Krukonis, V.J.

    1994-12-31

    A technology used by the petroleum industry for separation and purification and the coffee industry for caffeine removal is being used by a Hanford scientist with the prospect of remediating organic contaminated Hanford soil. The process is known as Supercritical Fluid Extraction or SFE. Dr. Timothy Moody of the Westinghouse Hanford Company and the Phasex Corporation of Lawrence, Mass., have conducted successful bench-scale experiments at the 50g, 500g, and 5kg levels showing that SFE can remove various chemicals from large volumes of contaminated soil. The results indicate that organic contaminant removal from soil is much more efficient than the current industrial uses of SFE.

  5. [Application prospect about bioremediation of polychlorinated biphenyls-contaminated soil with immobilized microorganism technique: a review].

    PubMed

    Hu, Jin-Xing; Su, Xiao-Mei; Han, Hui-Bo; Shen, Chao-Feng; Shi, Ji-Yan

    2014-06-01

    As one type of the persistent organic pollutants, polychlorinated biphenyls (PCBs) are tremendously harmful to organisms. These compounds are easily absorbed onto soil particles and able to accumulate in soil after they are released into the environment. Bioremediation technology of PCBs-contaminated soils has become a research hotspot in recent years, and immobilized microorganism technique has high developing and applying value because of its unique advantages in environmental remediation. This paper reviewed the chief remediation technology of PCBs-contaminated soils and then analyzed the characteristics of immobilized microorganism technique and its research progress in remediation of organic polluted soil. Finally, the feasibility and problems of this technique in remediation of PCBs-contaminated soil were also discussed.

  6. Electrokinetic remediation and microbial community shift of β-cyclodextrin-dissolved petroleum hydrocarbon-contaminated soil.

    PubMed

    Wan, Chunli; Du, Maoan; Lee, Duu-Jong; Yang, Xue; Ma, Wencheng; Zheng, Lina

    2011-03-01

    Electrokinetic (EK) migration of β-cyclodextrin (β-CD), which is inclusive of total petroleum hydrocarbon (TPH), is an economically beneficial and environmentally friendly remediation process for oil-contaminated soils. Remediation studies of oil-contaminated soils generally prepared samples using particular TPHs. This study investigates the removal of TPHs from, and electromigration of microbial cells in field samples via EK remediation. Both TPH content and soil respiration declined after the EK remediation process. The strains in the original soil sample included Bacillus sp., Sporosarcina sp., Beta proteobacterium, Streptomyces sp., Pontibacter sp., Azorhizobium sp., Taxeobacter sp., and Williamsia sp. Electromigration of microbial cells reduced the biodiversity of the microbial community in soil following EK remediation. At 200 V m(-1) for 10 days, 36% TPH was removed, with a small population of microbial cells flushed out, demonstrating that EK remediation is effective for the present oil-contaminated soils collected in field.

  7. Biochar and compost amendments enhance copper immobilisation and support plant growth in contaminated soils.

    PubMed

    Jones, Sarah; Bardos, R Paul; Kidd, Petra S; Mench, Michel; de Leij, Frans; Hutchings, Tony; Cundy, Andrew; Joyce, Chris; Soja, Gerhard; Friesl-Hanl, Wolfgang; Herzig, Rolf; Menger, Pierre

    2016-04-15

    Contamination of soil with trace elements, such as Cu, is an important risk management issue. A pot experiment was conducted to determine the effects of three biochars and compost on plant growth and the immobilisation of Cu in a contaminated soil from a site formerly used for wood preservation. To assess Cu mobility, amended soils were analysed using leaching tests pre- and post-incubation, and post-growth. Amended and unamended soils were planted with sunflower, and the resulting plant material was assessed for yield and Cu concentration. All amendments significantly reduced leachable Cu compared to the unamended soil, however, the greatest reductions in leachable Cu were associated with the higher biochar application rate. The greatest improvements in plant yields were obtained with the higher application rate of biochar in combination with compost. The results suggest joint biochar and compost amendment reduces Cu mobility and can support biomass production on Cu-contaminated soils. PMID:26850677

  8. Electrokinetic remediation and microbial community shift of β-cyclodextrin-dissolved petroleum hydrocarbon-contaminated soil.

    PubMed

    Wan, Chunli; Du, Maoan; Lee, Duu-Jong; Yang, Xue; Ma, Wencheng; Zheng, Lina

    2011-03-01

    Electrokinetic (EK) migration of β-cyclodextrin (β-CD), which is inclusive of total petroleum hydrocarbon (TPH), is an economically beneficial and environmentally friendly remediation process for oil-contaminated soils. Remediation studies of oil-contaminated soils generally prepared samples using particular TPHs. This study investigates the removal of TPHs from, and electromigration of microbial cells in field samples via EK remediation. Both TPH content and soil respiration declined after the EK remediation process. The strains in the original soil sample included Bacillus sp., Sporosarcina sp., Beta proteobacterium, Streptomyces sp., Pontibacter sp., Azorhizobium sp., Taxeobacter sp., and Williamsia sp. Electromigration of microbial cells reduced the biodiversity of the microbial community in soil following EK remediation. At 200 V m(-1) for 10 days, 36% TPH was removed, with a small population of microbial cells flushed out, demonstrating that EK remediation is effective for the present oil-contaminated soils collected in field. PMID:21052991

  9. Comparison of germination and seed vigor of sunflower in two contaminated soils of different texture

    NASA Astrophysics Data System (ADS)

    Zhao, Xin; Han, Jaemaro; Lee, Jong Keun; Kim, Jae Young

    2014-05-01

    Phytoremediation as an emerging low-cost and ecologically friendly alternative to the conventional soil remediation technologies has gained a great deal of attention and into lots of research. As a kind of the methods that use of green plants to remediate heavy metals contaminated soils, the early growth status of plant seeds in the contaminated environmental directly affects the effect of phytoremediation. Germination test in the water (aqueous solution of heavy metal) is generally used for assessing heavy metal phytotoxicity and possibility of plant growth, but there is a limit. Because soil is commonly main target of phytoremediation, not the water. The bioavailability of heavy metals in the soil also depends on the texture. So soil texture is an important factor of phytoremediation effect. Sunflower is the representative species which have good tolerance to various heavy metals; furthermore, the seeds of sunflower can be used as the raw-material for producing bio-diesel. The objectives of this research were to investigate germination rate of sunflowers in various heavy metal contaminated soils and to compare the seedling vigor index (SVI) of sunflower in two contaminated soils of different texture. Sunflower (Helianthusannuus L.) seeds were obtained from a commercial market. In order to prove the soil texture effect on heavy metal contaminated soil, germination tests in soil were conducted with two different types of soil texture (i.e., loam soil and sandy loam soil) classified by soil textural triangle (defined by USDA) including representative soil texture of Korea. Germination tests in soil were conducted using KS I ISO 11260-1 (2005) for reference that sunflower seeds were incubated for 7 days in dark at 25 ± 1 Celsius degree. The target heavy metals are Nickel (Ni) and Zinc (Zn). The Ni and Zn concentrations were 0, 10, 50, 100, 200, 300, 500 mg-Ni/kg-dry soil, and 0, 10, 50, 100, 300, 500, 900 mg-Zn/kg-dry soil, respectively. After germination test for 7

  10. Chryseobacterium taichungense sp. nov., isolated from contaminated soil.

    PubMed

    Shen, Fo-Ting; Kämpfer, Peter; Young, Chiu-Chung; Lai, Wei-An; Arun, A B

    2005-05-01

    A bacterial strain (CC-TWGS1-8(T)) isolated from a tar-contaminated soil in Taiwan was studied in a detailed taxonomic study. The cells were Gram-negative, rod-shaped and non-spore-forming. Phylogenetic analyses using the 16S rRNA gene sequence of the strain clearly revealed an affiliation to the genus Chryseobacterium, the highest sequence similarities being to the type strain of Chryseobacterium indologenes (96.8 %), to Chryseobacterium gleum (96.8 %) and to Chryseobacterium joostei (96.4 %). The 16S rRNA gene sequence similarities to all other Chryseobacterium species were below 96 %. The major whole-cell fatty acids were 15 : 0 iso (35.4 %) and 17 : 0 iso 3OH (22.5 %). DNA-DNA hybridization values and the biochemical and chemotaxonomic properties demonstrate that strain CC-TWGS1-8(T) represents a novel species, for which the name Chryseobacterium taichungense sp. nov. is proposed. The type strain is CC-TWGS1-8(T) (= CCUG 50001(T) = CIP 108519(T)).

  11. Thermal desorption of PCB-contaminated soil with sodium hydroxide.

    PubMed

    Liu, Jie; Qi, Zhifu; Zhao, Zhonghua; Li, Xiaodong; Buekens, Alfons; Yan, Jianhua; Ni, Mingjiang

    2015-12-01

    The thermal desorption was combined with sodium hydroxide to remediate polychlorinated biphenyl (PCB)-contaminated soil. The experiments were conducted at different temperatures ranging from 300 to 600 °C with three NaOH contents of 0.1, 0.5, and 1 %. The results showed that thermal desorption was effective for PCB removal, destruction, and detoxication, and the presence of NaOH enhanced the process by significant dechlorination. After treatment with 0.1 % NaOH, the removal efficiency (RE) increased from 84.8 % at 300 °C to 98.0 % at 600 °C, corresponding to 72.7 and 91.7 % of destruction efficiency (DE). With 1 % NaOH content treated at 600 °C, the RE and DE were 99.0 and 93.6 %, respectively. The effect of NaOH content on PCB removal was significant, especially at lower temperature, yet it weakened under higher temperature. The interaction between NaOH content and temperature influenced the PCB composition. The higher temperature with the help of NaOH effectively increased the RE and DE of 12 dioxin-like PCBs (based on WHO-TEQ).

  12. Characterization and solubility measurements of uranium-contaminated soils to support risk assessment

    SciTech Connect

    Elless, M.P.; Armstrong, A.Q.; Lee, S.Y.

    1997-05-01

    Remediation of uranium-contaminated soils is considered a high priority by the US Department of Energy because these soils, if left untreated, represent a hazard to the environment and human health. Because the risk to human health is a function of the solubility of uranium in the soils, the objectives of this work are to measure the uranium solubility of two contaminated soils, before and after remedial treatment, and determine the health risk associated with these soils. Two carbonate-rich, uranium-contaminated soils from the US Department of Energy Fernald Environmental Management Project facility near Cincinnati, Ohio, as well as two nearby background soils were characterized and their uranium solubility measured in a 75-d solubility experiment using acid rain, groundwater, lung serum, and stomach acid simulants. Results show that the soluble uranium levels of each soil by each simulant are greatly influenced by their contamination source term. Risk calculations and biokinetic modeling based on the solubility data show that the risks from the soil ingestion and groundwater ingestion pathways are the predominant contributors to the total carcinogenic risk, whereas the risk from the soil inhalation pathway is the smallest contributor to this risk. However, kidney toxicity was the greater health concern of the Fernald Environmental Management Project soils, primarily from undiluted ingestion of the groundwater solution following contact with the contaminated soils. Sensitivity analyses indicate that uranium solubility is a key parameter in defining kidney toxicity; therefore, without proper consideration of the solubility of radionuclides/metals in untreated and treated soils, important factors may be overlooked which may result in soil cleanup goals or limits which are not protective of human health and the environment.

  13. Time-dependent changes of zinc speciation in four soils contaminated with zincite or sphalerite.

    PubMed

    Voegelin, Andreas; Jacquat, Olivier; Pfister, Sabina; Barmettler, Kurt; Scheinost, Andreas C; Kretzschmar, Ruben

    2011-01-01

    The long-term speciation of Zn in contaminated soils is strongly influenced by soil pH, clay, and organic matter content as well as Zn loading. In addition, the type of Zn-bearing contaminant entering the soil may influence the subsequent formation of pedogenic Zn species, but systematic studies on such effects are currently lacking. We therefore conducted a soil incubation study in which four soils, ranging from strongly acidic to calcareous, were spiked with 2000 mg/kg Zn using either ZnO (zincite) or ZnS (sphalerite) as the contamination source. The soils were incubated under aerated conditions in moist state for up to four years. The extractability and speciation of Zn were assessed after one, two, and four years using extractions with 0.01 M CaCl(2) and Zn K-edge X-ray absorption fine structure (XAFS) spectroscopy, respectively. After four years, more than 90% of the added ZnO were dissolved in all soils, with the fastest dissolution occurring in the acidic soils. Contamination with ZnO favored the formation of Zn-bearing layered double hydroxides (LDH), even in acidic soils, and to a lesser degree Zn-phyllosilicates and adsorbed Zn species. This was explained by locally elevated pH and high Zn concentrations around dissolving ZnO particles. Except for the calcareous soil, ZnS dissolved more slowly than ZnO, reaching only 26 to 75% of the added ZnS after four years. ZnS dissolved more slowly in the two acidic soils than in the near-neutral and the calcareous soil. Also, the resulting Zn speciation was markedly different between these two pairs of soils: Whereas Zn bound to hydroxy-interlayered clay minerals (HIM) and octahedrally coordinated Zn sorption complexes prevailed in the two acidic soils, Zn speciation in the neutral and the calcareous soil was dominated by Zn-LDH and tetrahedrally coordinated inner-sphere Zn complexes. Our results show that the type of Zn-bearing contaminant phase can have a significant influence on the formation of pedogenic Zn

  14. Contaminant-induced changes to soil properties: From general overview to study of metal oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Ben Moshe, T.; Dror, I.; Yaron, B.; Berkowitz, B.

    2011-12-01

    A contemporary metapedogenetic process in which anthropogenic contaminants become an additional soil-forming factor is presented. Several examples that link contamination and modification of soil properties from the existing literature are reviewed. Also, recent experimental results that show possible soil property modifications as a result of application of metal oxide nanoparticles to natural soils are shown. Research results published in literature on chemical contaminant-soil interactions show that in some cases, irreversible changes to the soil matrix and properties may occur. In such cases, a pristine soil may become the parent material for a newly-formed soil. In contrast to natural processes over geological time scales, contaminant-induced soil modification occurs over much shorter time scales. In recent years, the effects of soil on the behavior and properties of nanoparticles released to the environment have been studied extensively. The behavior, transport and mobility of nanoparticles were shown to be strongly dependent on environmental conditions. However, little is known about the possible effects of nanoparticles on soil properties. In this study, two types of metal oxide nanoparticles, CuO and Fe3O4 were mixed with two types of soil and the effects of the nanoparticles on various soil properties were assessed. Metal oxide nanoparticles were previously shown to catalyze the oxidation of organic pollutants in aqueous suspensions, and they were therefore expected to induce changes in the organic material in the soil, especially upon addition of an oxidant. It was found that the nanoparticles did not change the total amount of organic materials in the soil or the total organic carbon in the soil extract; however, three-dimensional fluorescence spectroscopy demonstrated changes in humic substances.

  15. Closure Report for Corrective Action Unit 166: Storage Yards and Contaminated Materials, Nevada Test Site, Nevada

    SciTech Connect

    NSTec Environmental Restoration

    2009-08-01

    Corrective Action Unit (CAU) 166 is identified in the Federal Facility Agreement and Consent Order (FFACO) as 'Storage Yards and Contaminated Materials' and consists of the following seven Corrective Action Sites (CASs), located in Areas 2, 3, 5, and 18 of the Nevada Test Site: CAS 02-42-01, Condo Release Storage Yd - North; CAS 02-42-02, Condo Release Storage Yd - South; CAS 02-99-10, D-38 Storage Area; CAS 03-42-01, Conditional Release Storage Yard; CAS 05-19-02, Contaminated Soil and Drum; CAS 18-01-01, Aboveground Storage Tank; and CAS 18-99-03, Wax Piles/Oil Stain. Closure activities were conducted from March to July 2009 according to the FF ACO (1996, as amended February 2008) and the Corrective Action Plan for CAU 166 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, 2007b). The corrective action alternatives included No Further Action and Clean Closure. Closure activities are summarized. CAU 166, Storage Yards and Contaminated Materials, consists of seven CASs in Areas 2, 3, 5, and 18 of the NTS. The closure alternatives included No Further Action and Clean Closure. This CR provides a summary of completed closure activities, documentation of waste disposal, and confirmation that remediation goals were met. The following site closure activities were performed at CAU 166 as documented in this CR: (1) At CAS 02-99-10, D-38 Storage Area, approximately 40 gal of lead shot were removed and are currently pending treatment and disposal as MW, and approximately 50 small pieces of DU were removed and disposed as LLW. (2) At CAS 03-42-01, Conditional Release Storage Yard, approximately 7.5 yd{sup 3} of soil impacted with lead and Am-241 were removed and disposed as LLW. As a BMP, approximately 22 ft{sup 3} of asbestos tile were removed from a portable building and disposed as ALLW, approximately 55 gal of oil were drained from accumulators and are currently pending disposal as HW, the portable building was removed and disposed as

  16. [Carbon source utilization characteristics of microbial communities in a petroleum-contaminated soil in Daqing Oil Field, Northeast China].

    PubMed

    Yue, Bing-Bing; Li, Xin; Ren, Fang-Fei; Meng, Fan-Juan; Yin, Peng-Da; Zhang, Hui-Hui; Sun, Guang-Yu

    2011-12-01

    By using Biolog technique, this paper studied the carbon source utilization characteristics of microbial communities in different layers (0-10 cm, 10-20 cm, and 20-30 cm) of a petroleum-contaminated soil near an oil well having exploited for 36 years in Daqing Oil Field. Petroleum contamination enhanced the metabolic activity of the soil microbial communities obviously. In the three layers of the petroleum-contaminated soil, the metabolic activity of the microbes was higher than that of the control, and there existed significant differences between different layers of the petroleum-contaminated soil. The carbon source metabolic capacity of the microbes in different layers of the petroleum-contaminated soil was in the order of 20-30 cm > 10-20 cm > 0-10 cm. Petroleum contamination made the kinds of soil carbon source and the metabolic diversity of soil microbes increased, being more obvious in 10-20 cm and 20-30 cm soil layers but less change in 0-10 cm soil layer. In the contaminated soil, the majority of the carbon sources utilized by the microbes in 10-20 cm soil layer were carbohydrates instead of the carboxylic acids in non-contaminated soil, whereas the majority of the carbon substrates utilized in 20-30 cm soil layer were carboxylic acids. All the results suggested that petroleum-contaminated soil had its unique microbial community structure and peculiar microbial carbon source utilization characteristics.

  17. Speciation and phytoavailability of cadmium in soil treated with cadmium-contaminated rice straw.

    PubMed

    Wang, Shuai; Huang, Dao-You; Zhu, Qi-Hong; Zhu, Han-Hua; Liu, Shou-Long; Luo, Zun-Chang; Cao, Xiao-Ling; Wang, Ji-Yu; Rao, Zhong-Xiu; Shen, Xin

    2015-02-01

    When grown on Cd-contaminated soil, rice typically accumulates considerable Cd in straw, and which may return to the soil after harvest. This work was undertaken to assess the pollution risk of Cd associated to the Cd-contaminated rice straw after incorporating into an uncontaminated soil. With the Cd-contaminated rice straw added at 0, 1, 2, 3, 4 and 5 % (w/w), an incubation experiment (28 days) with non-planting and a followed pot experiment sequent with two planting (rice and Chinese cabbage, transplanted after 28-day incubation) were carried out to investigate the changes of soil Cd speciation and phytoavailability. The results indicated that the Cd-contaminated rice straw addition significantly increased soil pH and dissolved organic carbon during the 28-day incubation. For the high availability of Cd in contaminated rice straw, diethylenetriaminepentaacetic acid (DTPA) extractable Cd significantly increased, and the percentages of acetic acid extractable and reducible Cd in soil significantly enhanced after the addition of Cd-contaminated rice straw. However, the Cd-contaminated rice straw addition inhibited the rice growth and induced the decrease of Cd in rice grain and straw by 12.8 to 70.2 % and 39.3 to 57.3 %, respectively, whereas the Cd contents increased by 13.9 to 84.1 % in Chinese cabbage that planted after rice harvest. In conclusion, Cd associated with Cd-contaminated rice straw was highly available after incorporating into the soil, and thus the Cd pollution risk via the Cd-contaminated rice straw incorporation should be evaluated in the Cd-contaminated paddy region.

  18. Potential soil contaminant levels of polychlorinated dibenzodioxins and dibenzofurans at industrial facilities employing heat transfer operations

    SciTech Connect

    Korte, N.E.; Muhr, C.A.; Greene, D.W.

    1992-04-01

    Certain manufacturing facilities formerly used large quantities of polychlorinated biphenyl (PCB) fluids in heat transfer operations. At many of these locations, operations have also involved PCB-containing electrical equipment. Commonly, over many years of plant operations, spills and leaks have resulted in PCB soil contamination. Dioxins and furans have been associated with PCB contamination in both the technical and popular press. Consequently, the need for analyses for dioxins and furans must be evaluated at locations where soils are contaminated with PCBs. This report presents an evaluation of potential dioxin and furan soil contamination based on heat transfer operations and spills from electrical equipment. The following five scenarios were examined for dioxin and furan contamination: (1) impurities in heat transfer fluids, (2) formation during heat transfer operations, (3) pyrolysis of heat transfer fluids, (4) impurities in dielectric fluids, and (5) pyrolysis of dielectric fluids. The potential contamination with dioxins and furans was calculated and compared with a 20 ppb guideline that has been used by the Centers for Disease Control for dioxin in subsoil. The results demonstrated that dioxins are formed only under pyrolytic conditions and only from the trichlorobenzenes present in dielectric fluids. Furans are found as impurities in PCB fluids but, as with dioxins, are not formed in significant quantities except during pyrolysis. Fortunately, pyrolytic conditions involving PCB fluids and soil contamination are unlikely; therefore, analyses for dioxin and furan contamination in soils will rarely be needed.

  19. Bioavailability and mobility of organic contaminants in soil: new three-step ecotoxicological evaluation.

    PubMed

    Prokop, Zbyněk; Nečasová, Anežka; Klánová, Jana; Čupr, Pavel

    2016-03-01

    A novel approach was developed for rapid assessment of bioavailability and potential mobility of contaminants in soil. The response of the same test organism to the organic extract, water extract and solid phase of soil was recorded and compared. This approach was designed to give an initial estimate of the total organic toxicity (response to organic extractable fraction), as well as the mobile (response to water extract) and bioavailable fraction (response to solid phase) of soil samples. Eighteen soil samples with different levels of pollution and content of organic carbon were selected to validate the novel three-step ecotoxicological evaluation approach. All samples were chemically analysed for priority contaminants, including aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) and dichlordiphenyltrichloroethane (DDT). The ecotoxicological evaluation involved determination of toxicity of the organic, mobile and bioavailable fractions of soil to the test organism, bacterium Bacillus cereus. We found a good correlation between the chemical analysis and the toxicity of organic extract. The low toxicity of water extracts indicated low water solubility, and thus, low potential mobility of toxic contaminants present in the soil samples. The toxicity of the bioavailable fraction was significantly greater than the toxicity of water-soluble (mobile) fraction of the contaminants as deduced from comparing untreated samples and water extracts. The bioavailability of the contaminants decreased with increasing concentrations of organic carbon in evaluated soil samples. In conclusion, the three-step ecotoxicological evaluation utilised in this study can give a quick insight into soil contamination in context with bioavailability and mobility of the contaminants present. This information can be useful for hazard identification and risk assessment of soil-associated contaminants. Graphical Abstract New three-step ecotoxicological

  20. [Leaching Remediation of Copper and Lead Contaminated Lou Soil by Saponin Under Different Conditions].

    PubMed

    Deng, Hong-xia; Yang, Ya-li; Li, Zhen; Xu, Yan; Li, Rong-hua; Meng, Zhao-fu; Yang, Ya-ti

    2015-04-01

    In order to investigate the leaching remediation effect of the eco-friendly biosurfactant saponin for Cu and Pb in contaminated Lou soil, batch tests method was used to study the leaching effect of saponin solution on single Cu, Pb contaminated Lou soil and mixed Cu and Pb contaminated Lou soil under different conditions such as reaction time, mass concentration of saponin, pH, concentration of background electrolyte and leaching times. The results showed that the maximum leaching removal effect of Cu and Pb in contaminated Lou soil was achieved by complexation of the heavy metals with saponin micelle, when the mass concentration of saponin solution was 50 g x L(-1), pH was 5.0, the reaction time was 240 min, and there was no background electrolyte. In single and mixed contaminated Lou soil, the leaching percentages of Cu were 29.02% and 25.09% after a single leaching with 50 g x L(-1) saponin under optimal condition, while the single leaching percentages of Pb were 31.56% and 28.03%, respectively. The result indicated the removal efficiency of Pb was more significant than that of Cu. After 4 times of leaching, the cumulative leaching percentages of Cu reached 58.92% and 53.11%, while the cumulative leaching percentages of Pb reached 77.69% and 65.32% for single and mixed contaminated Lou soil, respectively. The fractionation results of heavy metals in soil before and after a single leaching showed that the contents of adsorbed and exchangeable Cu and Pb increased in the contaminated soil, while the carbonate-bound, organic bound and sulfide residual Cu and Pb in the contaminated Lou soil could be effectively removed by saponin.

  1. Remediation of saturated soil contaminated with petroleum products using air sparging with thermal enhancement.

    PubMed

    Mohamed, A M I; El-menshawy, Nabil; Saif, Amany M

    2007-05-01

    Pollutants in the form of non-aqueous phase liquids (NAPLs), such as petroleum products, pose a serious threat to the soil and groundwater. A mathematical model was derived to study the unsteady pollutant concentrations through water saturated contaminated soil under air sparging conditions for different NAPLs and soil properties. The comparison between the numerical model results and the published experimental results showed acceptable agreement. Furthermore, an experimental study was conducted to remove NAPLs from the contaminated soil using the sparging air technique, considering the sparging air velocity, air temperature, soil grain size and different contaminant properties. This study showed that sparging air at ambient temperature through the contaminated soil can remove NAPLs, however, employing hot air sparging can provide higher contaminant removal efficiency, by about 9%. An empirical correlation for the volatilization mass transfer coefficient was developed from the experimental results. The dimensionless numbers used were Sherwood number (Sh), Peclet number (Pe), Schmidt number (Sc) and several physical-chemical properties of VOCs and porous media. Finally, the estimated volatilization mass transfer coefficient was used for calculation of the influence of heated sparging air on the spreading of the NAPL plume through the contaminated soil.

  2. Accumulation and tolerance characteristics of zinc in Agropyron cristatum plants exposed to zinc-contaminated soil.

    PubMed

    Meng, Lin; Guo, Qiang; Mao, Peichun; Tian, Xiaoxia

    2013-09-01

    In phytoremediation, plants are used to stabilize or remove toxins from soil. In this study, a pot experiment was conducted in a greenhouse to evaluate the phytoremediation potential of Agropyron cristatum (Poaceae) grown on Zinc (Zn) contaminated soils. Results indicated that Zn accumulation in both shoots and roots increased with soil Zn concentration, and Zn concentrations in roots were greater than in shoots. A significantly negative correlation was found between translocation factor or bioconcentration factor values and Zn concentrations in soil. Overall, A. cristatum was Zn excluder with an innate capacity to tolerate Zn stress and may have potential for the phytostabilization of sites contaminated with Zn. PMID:23771314

  3. Ultrasonic desorption of petroleum hydrocarbons from crude oil contaminated soils.

    PubMed

    Li, Jianbing; Song, Xinyuan; Hu, Guangji; Thring, Ronald Wallen

    2013-01-01

    Ultrasonic irradiation was applied to improve the desorption of petroleum hydrocarbons (PHC) in crude oil from three types of soil. Soil A was an Ottawa sand, while soil B and soil C were fine soils that contained 27.6% and 55.3% of silt and clay contents, respectively. It was found that the ultrasonic desorption was highly related to soil types, with the highest and the lowest desorption occurring in coarse soil (i.e., soil A) and finer soil (i.e., soil C), respectively. Under the experimental conditions, the maximum ultrasonic desorption enhancement of the total petroleum hydrocarbons (TPH) reached 22% for soil A, 61% for soil B, and 49% for soil C, respectively. The maximum enhancement on the F2 (n-C10 to n-C16), F3 (n-C16 to n-C34), and F4 (n-C34 to n-C50) fractions of PHC reached 91, 44, and 51% for soil B, and 90, 38, and 31% for soil C, respectively. The desorption enhancement also illustrated an increasing trend with initial soil TPH concentration. PMID:23705614

  4. Potential impact of soil microbial heterogeneity on the persistence of hydrocarbons in contaminated subsurface soils.

    PubMed

    Aleer, Sam; Adetutu, Eric M; Weber, John; Ball, Andrew S; Juhasz, Albert L

    2014-04-01

    In situ bioremediation is potentially a cost effective treatment strategy for subsurface soils contaminated with petroleum hydrocarbons, however, limited information is available regarding the impact of soil spatial heterogeneity on bioremediation efficacy. In this study, we assessed issues associated with hydrocarbon biodegradation and soil spatial heterogeneity (samples designated as FTF 1, 5 and 8) from a site in which in situ bioremediation was proposed for hydrocarbon removal. Test pit activities showed similarities in FTF soil profiles with elevated hydrocarbon concentrations detected in all soils at 2 m below ground surface. However, PCR-DGGE-based cluster analysis showed that the bacterial community in FTF 5 (at 2 m) was substantially different (53% dissimilar) and 2-3 fold more diverse than communities in FTF 1 and 8 (with 80% similarity). When hydrocarbon degrading potential was assessed, differences were observed in the extent of (14)C-benzene mineralisation under aerobic conditions with FTF 5 exhibiting the highest hydrocarbon removal potential compared to FTF 1 and 8. Further analysis indicated that the FTF 5 microbial community was substantially different from other FTF samples and dominated by putative hydrocarbon degraders belonging to Pseudomonads, Xanthomonads and Enterobacteria. However, hydrocarbon removal in FTF 5 under anaerobic conditions with nitrate and sulphate electron acceptors was limited suggesting that aerobic conditions were crucial for hydrocarbon removal. This study highlights the importance of assessing available microbial capacity prior to bioremediation and shows that the site's spatial heterogeneity can adversely affect the success of in situ bioremediation unless area-specific optimizations are performed.

  5. Assessing the toxicity of contaminated soils using the nematode Caenorhabditis elegans as test organism.

    PubMed

    Höss, S; Jänsch, S; Moser, T; Junker, T; Römbke, J

    2009-10-01

    In this study, nine uncontaminated reference soils and 22 contaminated soils with different physico-chemical properties and contamination patterns were tested with a standardized toxicity test, using the nematode, Caenorhabditis elegans, as test organism. Fertility, growth and reproduction of C. elegans in the soils were compared with the exposure in standard soil Lufa St.2.2. C. elegans showed 100% fertility and a very low variability of growth in the reference soils. Although, reproduction varied considerably between the various reference soils, validity criteria (>30 offspring per test organism) were met in all reference soils. Moreover, Lufa St. 2.2 turned out to be a suitable and representative control soil. In order to clearly classify the effects of the polluted soils on C. elegans, toxicity thresholds were derived for nematode fertility (20% inhibition), growth (10% inhibition) and reproduction (40% inhibition) on the basis of the test inherent variability (MDD=minimal detectable difference), as well as their variability between the uncontaminated reference soils (MTI=maximal tolerable inhibition). The contaminated soils showed clear toxic effects on the nematodes, whereas the toxicity was better correlated to organic than to heavy metal contamination in bulk soil. Interestingly, the results of the nematode toxicity test were not well correlated with those of tests with oligochaetes, collembolans and plants, performed with the same soils, showing that the results are not redundant. The toxicity test using C. elegans turned out to be suitable for testing the toxicity of field collected soils and might by a valuable addition to soil test batteries.

  6. Efficiency of soil organic and inorganic amendments on the remediation of a contaminated mine soil: II. Biological and ecotoxicological evaluation.

    PubMed

    Pardo, T; Clemente, R; Alvarenga, P; Bernal, M P

    2014-07-01

    The feasibility of two organic materials (pig slurry and compost) in combination with hydrated lime for the remediation of a highly acidic trace elements (TEs) contaminated mine soil was assessed in a mesocosm experiment. The effects of the amendments on soil biochemical and ecotoxicological properties were evaluated and related with the main physicochemical characteristics of soil and soil solution. The original soil showed impaired basic ecological functions due to the high availability of TEs, its acidic pH and high salinity. The three amendments slightly reduced the direct and indirect soil toxicity to plants, invertebrates and microorganisms as a consequence of the TEs' mobility decrease in topsoil, reducing therefore the soil associated risks. The organic amendments, especially compost, thanks to the supply of essential nutrients, were able to improve soil health, as they stimulated plant growth and significantly increased enzyme activities related with the key nutrients in soil. Therefore, the use of compost or pig slurry, in combination with hydrated lime, decreased soil ecotoxicity and seems to be a suitable management strategy for the remediation of highly acidic TEs contaminated soils. PMID:24875876

  7. Efficiency of soil organic and inorganic amendments on the remediation of a contaminated mine soil: II. Biological and ecotoxicological evaluation.

    PubMed

    Pardo, T; Clemente, R; Alvarenga, P; Bernal, M P

    2014-07-01

    The feasibility of two organic materials (pig slurry and compost) in combination with hydrated lime for the remediation of a highly acidic trace elements (TEs) contaminated mine soil was assessed in a mesocosm experiment. The effects of the amendments on soil biochemical and ecotoxicological properties were evaluated and related with the main physicochemical characteristics of soil and soil solution. The original soil showed impaired basic ecological functions due to the high availability of TEs, its acidic pH and high salinity. The three amendments slightly reduced the direct and indirect soil toxicity to plants, invertebrates and microorganisms as a consequence of the TEs' mobility decrease in topsoil, reducing therefore the soil associated risks. The organic amendments, especially compost, thanks to the supply of essential nutrients, were able to improve soil health, as they stimulated plant growth and significantly increased enzyme activities related with the key nutrients in soil. Therefore, the use of compost or pig slurry, in combination with hydrated lime, decreased soil ecotoxicity and seems to be a suitable management strategy for the remediation of highly acidic TEs contaminated soils.

  8. Laboratory-scale bioremediation of oil-contaminated soil of Kuwait with soil amendment materials.

    PubMed

    Cho, B H; Chino, H; Tsuji, H; Kunito, T; Nagaoka, K; Otsuka, S; Yamashita, K; Matsumoto, S; Oyaizu, H

    1997-10-01

    A huge amount of oil-contaminated soil remains unremediated in the Kuwait desert. The contaminated oil has the potentiality to cause pollution of underground water and to effect the health of people in the neighborhood. In this study, laboratory scale bioremediation experiments were carried out. Hyponex (Hyponex, Inc.) and bark manure were added as basic nutrients for microorganisms, and twelve kinds of materials (baked diatomite, microporous glass, coconut charcoal, an oil-decomposing bacterial mixture (Formula X from Oppenheimer, Inc.), and eight kinds of surfactants) were applied to accelerate the biodegradation of oil hydrocarbons. 15% to 33% of the contaminated oil was decomposed during 43 weeks' incubation. Among the materials tested, coconut charcoal enhanced the biodegradation. On the contrary, the addition of an oil-decomposing bacterial mixture impeded the biodegradation. The effects of the other materials were very slight. The toxicity of the biodegraded compounds was estimated by the Ames test and the tea pollen tube growth test. Both of the hydrophobic (dichloromethane extracts) and hydrophilic (methanol extracts) fractions showed a very slight toxicity in the Ames test. In the tea pollen tube growth test, the hydrophobic fraction was not toxic and enhanced the growth of pollen tubes.

  9. Laboratory-scale bioremediation of oil-contaminated soil of Kuwait with soil amendment materials.

    PubMed

    Cho, B H; Chino, H; Tsuji, H; Kunito, T; Nagaoka, K; Otsuka, S; Yamashita, K; Matsumoto, S; Oyaizu, H

    1997-10-01

    A huge amount of oil-contaminated soil remains unremediated in the Kuwait desert. The contaminated oil has the potentiality to cause pollution of underground water and to effect the health of people in the neighborhood. In this study, laboratory scale bioremediation experiments were carried out. Hyponex (Hyponex, Inc.) and bark manure were added as basic nutrients for microorganisms, and twelve kinds of materials (baked diatomite, microporous glass, coconut charcoal, an oil-decomposing bacterial mixture (Formula X from Oppenheimer, Inc.), and eight kinds of surfactants) were applied to accelerate the biodegradation of oil hydrocarbons. 15% to 33% of the contaminated oil was decomposed during 43 weeks' incubation. Among the materials tested, coconut charcoal enhanced the biodegradation. On the contrary, the addition of an oil-decomposing bacterial mixture impeded the biodegradation. The effects of the other materials were very slight. The toxicity of the biodegraded compounds was estimated by the Ames test and the tea pollen tube growth test. Both of the hydrophobic (dichloromethane extracts) and hydrophilic (methanol extracts) fractions showed a very slight toxicity in the Ames test. In the tea pollen tube growth test, the hydrophobic fraction was not toxic and enhanced the growth of pollen tubes. PMID:9314191

  10. Plant--rhizosphere-microflora association during phytoremediation of PAH-contaminated soil.

    PubMed

    Muratova, A; Hūbner, Th; Tischer, S; Turkovskaya, O; Möder, M; Kuschk, P

    2003-01-01

    The capability of plants to promote the microbial degradation of pollutants in rhizosphere soil is a principal mechanism of phytoremediation of PAH-contaminated soil. The formation of a specific rhizosphere microbocenosis with a high degradative potential toward contaminants is largely determined by plant species. The comparative PAH-degradation in unplanted soil and in soil planted with reed (Phragmites australis) and alfalfa (Medicago sativa) was studied in pot experiments during 2 years. Both alfalfa and reed successfully remediated contaminated soil by degrading 74.5 and 68.7% of PAHs, respectively. The study of the rhizosphere, rhizoplane, and unplanted-soil microflora in experimental pots showed that alfalfa stimulated the rhizosphere microflora of PAH-contaminated soil more effectively than did reed. Alfalfa clearly enhanced both the total number of microorganisms (1.3 times, according to fluorescence microscopy data) and the rate of the PAH-degrading population (almost seven times, according to plate counting). The degradative potential of its rhizosphere microflora toward PAHs was higher than the degradative activity of the reed rhizosphere. This study provides relevant information for the successful application of alfalfa to phytoremediate PAH-contaminated soil.

  11. Biological treatment of TNT-contaminated soil. 2: Biologically induced immobilization of the contaminants and full-scale application

    SciTech Connect

    Lenke, H.; Daun, G.; Sieglen, U.; Knackmuss, H.J.; Warrelmann, J.; Walter, U.; Hund, K.

    1998-07-01

    Anaerobic treatment of originally contaminated soil from a former ammunition plant was carried out in a laboratory slurry reactor. While fermenting glucose to ethanol, acetate, and propionate, the anaerobic bacteria completely reduced the nitro groups of 2,4,6-trinitrotoluene (TNT) and aminodinitrotoluenes, which led to a complete and irreversible binding of the reduced products to the soil. 2,4-dinitrotoluene and hexahydro-1,3,5-trinitro-1,3,5-triazine were also reduced in the soil slurry and were no longer detectable after the anaerobic treatment. To mineralize the fermentation products, a subsequent aerobic treatment was necessary to complete the bioremediation process. This bioremediation process was tested in a technical scale at Hessisch Lichtenau-Hirschhagen, Germany. A sludge reactor (Terranox system) was filled with 18 m{sup 3} of contaminated soil (main contaminants were TNT, 2,4-dinitrotoluene, hexahydro-1,3,5-trinitro-1,3,5-triazine) and 10 m{sup 3} of water. The anaerobic stage was carried out by periodical feeding of sucrose. The sludge was subsequently dewatered and treated aerobically. Chemical analysis revealed an overall reduction of more than 99% of the contaminants. Ecotoxicological tests performed with various aquatic systems (luminescent bacteria, daphnids, algae) and terrestrial systems (respiring bacteria, nitrifying bacteria, cress plants, earth worms) showed that residual toxicity could not be detected after the anaerobic/aerobic treatment.

  12. ON-SITE TREATMENT OF CREOSOTE AND PENTACHLOROPHENOL SLUDGES AND CONTAMINATED SOIL

    EPA Science Inventory

    Information is presented for quantitative evaluation of treatment potential for creosote and pentachlorophenol (PCP) wood treating contaminants in soil systems. The study was conducted in three phases: 1) characterization, (2) treatability screening and (3) field evaluation. Data...

  13. Use of immunoassay testing and landfarming to remediate pesticide - contaminated soil at agrichemical businesses

    SciTech Connect

    Frank, J.F.

    1994-12-31

    The recent combination of two new technologies - immunoassay and landfarming - now offers an efficient, effective and economical option in the remediation of pesticide-contaminated soil. Participation in 28 landfarming projects in Illinois - 20 with pesticide-contaminated soil and eight with fuel-contaminated soil - has convinced the author that the combination offers the best method of remediation for most agrichemical sites. The procedures are currently used in Illinois as well as several other states and are being considered in even more. This paper describes the legislative and regulatory background for landfarming; defines immunoassay testing; defines landfarming: (1) contaminated site sampling and analysis; (2) education of participants; (3) selection of cooperator and host farm; (4) soil spreading considerations; a. rates, b. techniques; host site sampling and analysis; and factors affecting cost.

  14. 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.

  15. 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.

  16. ISSUES IN ASSESSING LOW LEVEL IONIZABLE CONTAMINANT PARTITIONING IN SOILS AND SEDIMENTS

    EPA Science Inventory

    Solubilization has profound implications for such diverse risk assessment activities as assessing sediment contaminant porewater exposures to benthic fauna, determining half lives of refractory toxicants in natural soils and sediments, and assessing the fate and transport of th...