Science.gov

Sample records for soil remediation demonstration

  1. SITE Technology Capsule. Demonstration of Rocky Mountain Remediation Services Soil Amendment

    EPA Science Inventory

    This report briefly summarizes the Rocky Mountain Remediation Services treatment technology demonstration of a soil amendment process for lead contaminated soil at Roseville, OH. The evaluation included leaching, bioavailability, geotechnical, and geochemical methods.

  2. Review of the Vortec soil remediation demonstration program

    SciTech Connect

    Patten, J.S.

    1994-11-01

    The DOE`s clean-up of its nuclear complex require the development of innovative technologies to convert soils contaminated by hazardous and/or radioactive wastes to forms which can be readily disposed in accordance with current waste disposal methods. The unique features of Votec CMS technology should make it particularly cost-effective process for the vitrification of soils, sediments, sludges, and mill tailings containing organic metallic and/or radioactive contaminants. This article describes the technology (Votec`s combustion and melting system), the results of testing, the demonstration plant system, and summarizes the future schedule and the equipment needed. 3 figs., 3 tabs.

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

    SciTech Connect

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

    1995-11-01

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

  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. SITE TECHNOLOGY CAPSULE DEMONSTRATION OF ROCKY MOUNTAIN REMEDIATION SERVICES SOIL AMENDMENT PROCESS

    EPA Science Inventory

    RMRS developed the Envirobond� process to treat heavy metals in soil.This phosphate-based technology consists of a proprietary powder and solution that binds with metals in contaminated waste. RMRS claims that the Envirobond� process converts metal contaminants from their leachab...

  6. Laboratory Experiment on Electrokinetic Remediation of Soil

    ERIC Educational Resources Information Center

    Elsayed-Ali, Alya H.; Abdel-Fattah, Tarek; Elsayed-Ali, Hani E.

    2011-01-01

    Electrokinetic remediation is a method of decontaminating soil containing heavy metals and polar organic contaminants by passing a direct current through the soil. An undergraduate chemistry laboratory is described to demonstrate electrokinetic remediation of soil contaminated with copper. A 30 cm electrokinetic cell with an applied voltage of 30…

  7. Remediation and Reuse of Soils

    NASA Astrophysics Data System (ADS)

    Zihms, Stephanie; Switzer, Christine; Tarantino, Alessandro

    2013-04-01

    Links between contaminant remediation and impacts on soil properties have not been explored in a systematic way. Most remediation studies focus on the effectiveness of the remediation process. Contamination and remediation can have significant effects on soil properties and function. Considering that in most remediation cases the soil will be re-used in some way, it is important to understand the effects of the remediation process on soil properties and the post-remediation soil behaviour. This understanding can help to determine the best re-use of the soil and therefore improve post-remediation site development. Laboratory experiments on coal tar contaminated soil treated with smouldering remediation show that thermal treatments affect a variety of soil properties ranging from mineralogical composition, particle size distribution, and pH. Dynamic responses like permeability and shear strength are impacted as well and these responses are linked to the changes in soil properties. Soil permeability, capillary rise, and contact angle change dramatically after this remediation process, indicating some degree of hydrophobicity and significant implications for water movement through the post-remediation soil. The observed changes in permeability are linked to physical changes to the soil grain surface combined with small amounts (<1ppm) of coal tar and combustion product residue. Decoupling these effects is essential to understanding the extent of impact remediation processes have on long-term soil function. While chemical residue within the pores can be removed through "polishing" remediation steps, physical changes are likely to be permanent. Physical changes and chemical residue also have important implications with respect to the response of the soil under shear. These observed changes indicate that the remediated soil and its behaviour should be considered by remediation research. Monitoring of soil properties and behaviour during aggressive remediation can improve

  8. REMOVAL OF ISOPROPHYL ALCOHOL FROM A SURFACTANT-BASED SOIL REMEDIATION FLUID BY PERVAPORATION: PILOT SCALE FIELD DEMONSTRATION

    EPA Science Inventory

    The USEPA, NRMRL participated in a field demonstration of a surfactant enhanced aquifer remediation (SEAR) process. The main purpose of this field demonstration was to combine and optimize the subsurface extraction of a dense non-aqueous phase liquid with the above ground deconta...

  9. Innovative Vitrification for Soil Remediation

    SciTech Connect

    Hnat, James G.; Patten, John S.; Jetta, Norman W.

    1996-12-31

    Vortec has successfully completed Phases 1 and 2 of a technology demonstration program for an ''Innovative Fossil Fuel Fired Vitrification Technology for Soil Remediation.'' The principal objective of the program is to demonstrate the ability of a Vortec Cyclone Melting System (CMS) to remediate DOE contaminated soils and other waste forms containing TM RCRA hazardous materials, low levels of radionuclides and TSCA (PCB) containing wastes. The demonstration program will verify the ability of this vitrification process to produce a chemically stable glass final waste form which passes both TCLP and PCT quality control requirements, while meeting all federal and state emission control regulations. The demonstration system is designed to process 36 ton/day of as-received drummed or bulk wastes. The processing capacity equates to approximately 160 barrels/day of waste materials containing 30% moisture at an average weight of 450 lbs./barrel.

  10. ELECTROCHEMICAL REMEDIATION TECHNOLOGIES (ECRTS) DEMONSTRATION BULLETIN

    EPA Science Inventory

    The ElectroChemical Remediation Technologies (ECRTs) process was developed by P2-Soil Remediation, Inc. P-2 Soil Remediation, Inc. formed a partnership with Weiss Associates and ElectroPetroleum, Inc. to apply the technology to contaminated sites. The ECRTs process was evaluated ...

  11. Field demonstration of a full-scale in situ thermal desorption system for the remediation of soil containing PCBS and other hydrocarbons

    SciTech Connect

    Sheldon, R.B.; Iben, I.E.T.; Edelstein, W.A.

    1996-12-31

    A field demonstration of a full-sale, innovative and cost-effective remediation system using in situ thermal description (ISTD) was conducted at a state Superfund site in the northeastern United States in early 1996. The Demonstration was performed as part of the regulatory process to obtain a nationwide Toxic Substances Control Act (TSCA) permit for the remediation of soils containing PCBs at concentrations up to 5,000 ppm. An area of approximately 4800 square feet was remediated during six applications of an in situ Thermal Blanket covering an area of 800 square feet. Each application utilized five 160 square foot, electrically heated, 100-kilowatt modules. The Thermal Blanket heaters were operated at temperatures as high as 925 C. The modules contain 10 in. of vermiculite insulation to reduce upward heat losses to less than 10% of total power. The modules are covered with an impermeable silicone sheet and the in situ process is run at negative pressure to collect contaminants, prevent contaminant migration and eliminate odors. Off-gas emissions are controlled by a vapor extraction system comprised of a cyclonic separator for particulate removal, a flameless thermal oxidizer for destruction of residual contaminants, and a carbon polishing unit. Treatment times ranged from slightly more than 24 hours to treat the upper six inches to approximately four days to treat soil 12 to 18 inches deep. Temperature profiles and remedial efficiency are consistent with results from a computer thermal simulator. Post-treatment soil samples demonstrated the capability to achieve stringent soil cleanup levels of less than 2 ppm for PCBs while concurrently meeting ambient air quality standards with respect to air emissions and worker exposure limits. The Thermal Blanket is less intrusive than other permanent remedies and produces less noise, generates less dust and has a minimum of other impacts on the surrounding community.

  12. Soil Remediation Test

    SciTech Connect

    Manlapig, D. M.; Williamsws

    2002-04-01

    Soils contaminated with petroleum by-products can now be effectively remediated using a variety of technologies. Among these are in-situ bioremediation, land farming, and landfill/replacing of soil. The range of efficiencies and cost effectiveness of these technologies has been well documented. Exsorbet Plus is showing promise as an in-situ bioremediation agent. It is made of naturally grown Spaghnum Peat Moss which has been activated for encapsulation and blended with nitrogen-rich fertilizer. In its initial field test in Caracas, Venezuela, it was able to remediate crude oil-contaminated soil in 90 days at less than half of the cost of competing technologies. Waste Solutions, Corp and the US Department of Energy signed a Cooperative Research and Development Agreement to test Exsorbet Plus at the Rocky Mountain Oilfield Testing Center near Casper, Wyoming. As part of the test, soil contaminated with crude oil was treated with Exsorbet Plus to aid the in-situ bioremediation process. Quantitative total petroleum hydrocarbon (TPH) measurements were acquired comparing the performance of Exsorbet Plus with an adjacent plot undergoing unaided in-situ bioremediation.

  13. Water as a Reagent for Soil Remediation

    SciTech Connect

    Jayaweera, Indira S.; Marti-Perez, Montserrat; Diaz-Ferrero, Jordi; Sanjurjo, Angel

    2003-03-06

    SRI International conducted experiments in a two-year, two-phase process to develop and evaluate hydrothermal extraction technology, also known as hot water extraction (HWE) technology, for remediating petroleum-contaminated soils. The bench-scale demonstration of the process has shown great promise, and the implementation of this technology will revolutionize the conventional use of water in soil remediation technologies and provide a standalone technology for removal of both volatile and heavy components from contaminated soil.

  14. Saxton soil remediation project

    SciTech Connect

    Holmes, R.D.

    1995-12-31

    The Saxton Nuclear Experimental Facility (SNEF) consists of a 23-MW(thermal) pressurized light water thermal reactor located in south central Pennsylvania. The Saxton Nuclear Experimental Corporation (SNEC), a wholly owned subsidiary of the General Public Utilities (GPU) Corporation, is the licensee for the SNEF. Maintenance and decommissioning activities at the site are conducted by GPU Nuclear, also a GPU subsidiary and operator of the Three Mile Island and Oyster Creek nuclear facilities. The remediation and radioactive waste management of contaminated soils is described.

  15. 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.

  16. Results of the Lasagna{trademark} Phase IIa field demonstration for the remediation of TCE in clay soils

    SciTech Connect

    Athmer, C.J.; Ho, S.V.; Hughes, B.M.; Clausen, J.L.; Johnstone, F.; Hines, R.L.

    1998-12-31

    The Lasagna{trademark} technology is an integrated in-situ treatment in which established geotechnical methods are used to install degradation zones directly in the contaminated soil and electrokinetics is utilized to move the contaminants through those zones until the treatment is completed. The Phase IIa demonstration was the second field demonstration at a trichloroethylene (TCE) contaminated site in Paducah, Ky. The first demonstration, Phase I, proved that TCE could be mobilized and captured using Lasagna{trademark}. This second demonstration measured 30 feet by 21 feet by 45 feet deep and showed for the first time TCE, including pure phase residual TCE, could be mobilized in tight soils using electrokinetics and degraded in-situ using iron filings. Over 95% removal of TCE was observed in areas of the demonstration site including pure phase residual TCE regions.

  17. DEMONSTRATION OF ELECTROCHEMICAL REMEDIATION TECHNOLOGIES-INDUCED COMPLEXATION

    SciTech Connect

    Barry L. Burks

    2002-12-01

    The Project Team is submitting this Topical Report on the results of its bench-scale demonstration of ElectroChemical Remediation Technologies (ECRTs) and in particular the Induced Complexation (ECRTs-IC) process for remediation of mercury contaminated soils at DOE Complex sites. ECRTs is an innovative, in-situ, geophysically based soil remediation technology with over 50 successful commercial site applications involving remediation of over two million metric tons of contaminated soils. ECRTs-IC has been successfully used to remediate 220 cu m of mercury-contaminated sediments in the Union Canal, Scotland. In that operation, ECRTs-IC reduced sediment total mercury levels from an average of 243 mg/kg to 6 mg/kg in 26 days of operation. The clean up objective was to achieve an average total mercury level in the sediment of 20 mg/kg.

  18. Innovative vitrification for soil remediation

    SciTech Connect

    Jetta, N.W.; Patten, J.S.; Hart, J.G.

    1995-12-01

    The objective of this DOE demonstration program is to validate the performance and operation of the Vortec Cyclone Melting System (CMS{trademark}) for the processing of LLW contaminated soils found at DOE sites. This DOE vitrification demonstration project has successfully progressed through the first two phases. Phase 1 consisted of pilot scale testing with surrogate wastes and the conceptual design of a process plant operating at a generic DOE site. The objective of Phase 2, which is scheduled to be completed the end of FY 95, is to develop a definitive process plant design for the treatment of wastes at a specific DOE facility. During Phase 2, a site specific design was developed for the processing of LLW soils and muds containing TSCA organics and RCRA metal contaminants. Phase 3 will consist of a full scale demonstration at the DOE gaseous diffusion plant located in Paducah, KY. Several DOE sites were evaluated for potential application of the technology. Paducah was selected for the demonstration program because of their urgent waste remediation needs as well as their strong management and cost sharing financial support for the project. During Phase 2, the basic nitrification process design was modified to meet the specific needs of the new waste streams available at Paducah. The system design developed for Paducah has significantly enhanced the processing capabilities of the Vortec vitrification process. The overall system design now includes the capability to shred entire drums and drum packs containing mud, concrete, plastics and PCB`s as well as bulk waste materials. This enhanced processing capability will substantially expand the total DOE waste remediation applications of the technology.

  19. X-231A demonstration of in-situ remediation of DNAPL compounds in low permeability media by soil fracturing with thermally enhanced mass recovery or reactive barrier destruction

    SciTech Connect

    Siegrist, R.L. |; Lowe, K.S.; Murdoch, L.D. |; Slack, W.W.; Houk, T.C.

    1998-03-01

    The overall goal of the program of activities is to demonstrate robust and cost-effective technologies for in situ remediation of DNAPL compounds in low permeability media (LPM), including adaptations and enhancements of conventional technologies to achieve improved performance for DNAPLs in LPM. The technologies sought should be potential for application at simple, small sites (e.g., gasoline underground storage tanks) as well as at complex, larger sites (e.g., DOE land treatment units). The technologies involved in the X-231A demonstration at Portsmouth Gaseous Diffusion Plant (PORTS) utilized subsurface manipulation of the LPM through soil fracturing with thermally enhanced mass recovery or horizontal barrier in place destruction. To enable field evaluation of these approaches, a set of four test cells was established at the X-231A land treatment unit at the DOE PORTS plant in August 1996 and a series of demonstration field activities occurred through December 1997. The principal objectives of the PORTS X-231A demonstration were to: determine and compare the operational features of hydraulic fractures as an enabling technology for steam and hot air enhanced soil vapor extraction and mass recovery, in situ interception and reductive destruction by zero valent iron, and in situ interception and oxidative destruction by potassium permanganate; determine the interaction of the delivered agents with the LPM matrix adjacent to the fracture and within the fractured zone and assess the beneficial modifications to the transport and/or reaction properties of the LPM deposit; and determine the remediation efficiency achieved by each of the technology strategies.

  20. Innovative vitrification for soil remediation

    SciTech Connect

    Jetta, N.W.; Patten, J.S.; Hnat, J.G.

    1995-10-01

    The objective of this DOE demonstration program is to validate the performance and operation of the Vortec Cyclone Melting System (CMS{trademark}) for the processing of LLW contaminated soils found at DOE sites. This DOE vitrification demonstration project has successfully progressed through the first two phases. Phase I consisted of pilot scale testing with surrogate wastes and the conceptual design of a process plant operating at a generic DOE site. The objective of Phase 2, which is scheduled to be completed the end of FY 95, is to develop a definitive process plant design for the treatment of wastes at a specific DOE facility. During Phase 2, a site specific design was developed for the processing of LLW soils and muds containing TSCA organics and RCRA metal contaminants. Phase 3 will consist of a full scale demonstration at the DOE gaseous diffusion plant located in Paducah, KY. Several DOE sites were evaluated for potential application of the technology. Paducah was selected for the demonstration program because of their urgent waste remediation needs as well as their strong management and cost sharing financial support for the project.

  1. SOIL BIOVENTING DEMONSTRATION PROJECT

    EPA Science Inventory

    A pilot scale demonstration project of a soil bioventing system, which utilizes the biodegradation in soil and physical removal of VOC by induced air flow, is in operation at the U.S. Coast Guard Aviation Field in Traverse City, Michigan. he system is being tested to determine it...

  2. ENHANCED REMEDIATION DEMONSTRATIONS AT HILL AFB: INTRODUCTION

    EPA Science Inventory

    Nine enhanced aquifer remediation technologies were demonstrated side-by-side at a Hill Air Force Base Chemical Disposal Pit/Fire Training Area site. The demonstrations were performed inside 3 x 5 m cells isolated from the surrounding shallow aquifer by steel piling. The site w...

  3. Lasagna{trademark} soil remediation

    SciTech Connect

    1996-04-01

    Lasagna{trademark} is an integrated, in situ remediation technology being developed which remediates soils and soil pore water contaminated with soluble organic compounds. Lasagna{trademark} is especially suited to sites with low permeability soils where electroosmosis can move water faster and more uniformly than hydraulic methods, with very low power consumption. The process uses electrokinetics to move contaminants in soil pore water into treatment zones where the contaminants can be captured and decomposed. Initial focus is on trichloroethylene (TCE), a major contaminant at many DOE and industrial sites. Both vertical and horizontal configurations have been conceptualized, but fieldwork to date is more advanced for the vertical configuration. Major features of the technology are electrodes energized by direct current, which causes water and soluble contaminants to move into or through the treatment layers and also heats the soil; treatment zones containing reagents that decompose the soluble organic contaminants or adsorb contaminants for immobilization or subsequent removal and disposal; and a water management system that recycles the water that accumulates at the cathode (high pH) back to the anode (low pH) for acid-base neutralization. Alternatively, electrode polarity can be reversed periodically to reverse electroosmotic flow and neutralize pH.

  4. Lasagna{trademark} soil remediation

    SciTech Connect

    1996-04-01

    Lasagna{trademark} is an integrated, in situ remediation technology being developed by an industrial consortium consisting of Monsanto, E. I. DuPont de Nemours & Co., Inc. (DuPont), and General Electric, with participation from the Department of Energy (DOE) Office of Environmental Management, Office of Science and Technology (EM-50), and the Environmental Protection Agency (EPA) Office of Research and Development (Figure 1). Lasagna{trademark} remediates soils and soil pore water contaminated with soluble organic compounds. Lasagna{trademark} is especially suited to sites with low permeability soils where electroosmosis can move water faster and more uniformly than hydraulic methods, with very low power consumption. The process uses electrokinetics to move contaminants in soil pore water into treatment zones where the contaminants can be captured or decomposed. Initial focus is on trichloroethylene (TCE), a major contaminant at many DOE and industrial sites. Both vertical and horizontal configurations have been conceptualized, but fieldwork to date is more advanced for the vertical configuration.

  5. WATER AS A REAGENT FOR SOIL REMEDIATION

    SciTech Connect

    Indira S. Jayaweera; Montserrat Marti-Perez; Jordi Diaz-Ferrero; Angel Sanjurjo

    2001-11-12

    SRI International conducted experiments in a two-year, two-phase process to develop and evaluate hydrothermal extraction technology, also known as hot water extraction (HWE) technology, to separate petroleum-related contaminants and other hazardous pollutants from soil and sediments. In this process, water with added electrolytes (inexpensive and environmentally friendly) is used as the extracting solvent under subcritical conditions (150-300 C). The use of electrolytes allows us to operate reactors under mild conditions and to obtain high separation efficiencies that were hitherto impossible. Unlike common organic solvents, water under subcritical conditions dissolves both organics and inorganics, thus allowing opportunities for separation of both organic and inorganic material from soil. In developing this technology, our systematic approach was to (1) establish fundamental solubility data, (2) conduct treatability studies with industrial soils, and (3) perform a bench-scale demonstration using a highly contaminated soil. The bench-scale demonstration of the process has shown great promise. The next step of the development process is the successful pilot demonstration of this technology. Once pilot tested, this technology can be implemented quite easily, since most of the basic components are readily available from mature technologies (e.g., steam stripping, soil washing, thermal desorption). The implementation of this technology will revolutionize the conventional use of water in soil remediation technologies and will provide a stand-alone technology for removal of both volatile and heavy components from contaminated soil.

  6. EDTA retention and emissions from remediated soil.

    PubMed

    Jez, Erika; Lestan, Domen

    2016-05-01

    EDTA-based remediation is reaching maturity but little information is available on the state of chelant in remediated soil. EDTA soil retention was examined after extracting 20 soil samples from Pb contaminated areas in Slovenia, Austria, Czech Republic and USA with 120 mM kg(-1) Na2H2EDTA, CaNa2EDTA and H4EDTA for 2 and 24 h. On average, 73% of Pb was removed from acidic and 71% from calcareous soils (24 h extractions). On average, 15% and up to 64% of applied EDTA was after remediation retained in acidic soils. Much less; in average 1% and up to the 22% of EDTA was retained in calcareous soils. The secondary emissions of EDTA retained in selected remediated soil increased with the acidity of the media: the TCLP (Toxicity Characteristic Leaching Procedure) solution (average pH end point 3.6) released up to 36% of EDTA applied in the soil (28.1 mmol kg(-1)). Extraction with deionised water (pH > 6.0) did not produce measurable EDTA emissions. Exposing soil to model abiotic (thawing/freezing cycles) and biotic (ingestion by earthworms Lumbricus rubellus) ageing factors did not induce additional secondary emissions of EDTA retained in remediated soil. PMID:26943741

  7. Electrokinetic soil remediation--critical overview.

    PubMed

    Virkutyt, Jurate; Sillanpää, Mika; Latostenmaa, Petri

    2002-04-22

    In recent years, there has been increasing interest in finding new and innovative solutions for the efficient removal of contaminants from soils to solve groundwater, as well as soil, pollution. The objective of this review is to examine several alternative soil-remediating technologies, with respect to heavy metal remediation, pointing out their strengths and drawbacks and placing an emphasis on electrokinetic soil remediation technology. In addition, the review presents detailed theoretical aspects, design and operational considerations of electrokinetic soil-remediation variables, which are most important in efficient process application, as well as the advantages over other technologies and obstacles to overcome. The review discusses possibilities of removing selected heavy metal contaminants from clay and sandy soils, both saturated and unsaturated. It also gives selected efficiency rates for heavy metal removal, the dependence of these rates on soil variables, and operational conditions, as well as a cost-benefit analysis. Finally, several emerging in situ electrokinetic soil remediation technologies, such as Lasagna, Elektro-Klean, electrobioremediation, etc., are reviewed, and their advantages, disadvantages and possibilities in full-scale commercial applications are examined. PMID:12049409

  8. Uranium soils integrated demonstration, 1993 status

    SciTech Connect

    Nuhfer, K.

    1994-08-01

    The Fernald Environmental Management Project (FEMP), operated by the Fernald Environmental Restoration Management Corporation (FERMCO) for the DOE, was selected as the host site for the Uranium Soils Integrated Demonstration. The Uranium Soils ID was established to develop and demonstrate innovative remediation methods which address the cradle to grave elements involved in the remediation of soils contaminated with radionuclides, principally uranium. The participants in the ID are from FERMCO as well as over 15 other organizations from DOE, private industry and universities. Some of the organizations are technology providers while others are members of the technical support groups which were formed to provide technical reviews, recommendations and labor. The following six Technical Support Groups (TSGs) were formed to focus on the objective of the ID: Characterization, Excavation, Decontamination, Waste Treatment/Disposal, Regulatory, and Performance Assessment. This paper will discuss the technical achievements made to date in the program as well as the future program plans. The focus will be on the realtime analysis devices being developed and demonstrated, the approach used to characterize the physical/chemical properties of the uranium waste form in the soil and lab scale studies on methods to remove the uranium from the soil.

  9. 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.

  10. 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.

  11. Encapsulation as a passive soil remediation alternative

    SciTech Connect

    Mario, B.R. De

    1996-12-31

    By implementing institutional and engineering controls, a passive, cost-effective, remedial alternative has allowed redevelopment of an abandoned, industrial, site located in Newark, New Jersey. Soil and groundwater contaminants at the site include volatile and semi-volatile organic compounds and metals. The New Jersey Department of Environmental Protection (NJDEP) recognized the impracticality of requiring an aggressive, localized, remedial action to clean up contaminated soil and groundwater in a region that has historically used fill to create land along the state`s waterways. By placing an institutional control, known as a Declaration of Environmental Restriction (DER), on the property, the NJDEP allowed contaminated fill to remain on site and approved encapsulation as the remedial action for the soil. The approved engineering control, encapsulation, consisted of the design and placement of an asphalt pavement cap that covered the affected areas of concern. The asphalt pavement cap prevents direct human contact to contaminated soil and leaching of contaminants in the soil into the groundwater by surface water infiltration. This paper focuses on the subsurface soil investigation and establishment of the DER. The benefits of this remedial alternative are: (1) the urban redevelopment of contaminated land while simultaneously ensuring protection to human health and the environment; (2) costs savings of not having to clean up a regional problem as if it were local; and (3) the facilitation of a property transfer transaction without the risk of future liability for an historical problem.

  12. 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)

  13. Remediation of Soil at Nuclear Sites

    SciTech Connect

    Holmes, R.; Boardman, C.; Robbins, R; Fox, Robert Vincent; Mincher, Bruce Jay

    2000-03-01

    As the major nuclear waste and decontamination and decommissioning projects progress, one of the remaining problems that faces the nuclear industry is that of site remediation. The range of contamination levels and contaminants is wide and varied and there is likely to be a significant volume of soil contaminated with transuranics and hazardous organic materials that could qualify as mixed TRU waste. There are many technologies that offer the potential for remediating this waste but few that tackle all or most of the contaminants and even fewer that have been deployed with confidence. This paper outlines the progress made in proving the ability of Supercritical Fluid Extraction as a method of remediating soil, classified as mixed (TRU) transuranic waste.

  14. 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

  15. Uranium soils integrated demonstration: Soil characterization project report

    SciTech Connect

    Cunnane, J.C.; Gill, V.R.; Lee, S.Y.; Morris, D.E.; Nickelson, M.D.; Perry, D.L.; Tidwell, V.C.

    1993-08-01

    An Integrated Demonstration Program, hosted by the Fernald Environmental Management Project (FEMP), has been established for investigating technologies applicable to the characterization and remediation of soils contaminated with uranium. Critical to the design of relevant treatment technologies is detailed information on the chemical and physical characteristics of the uranium waste-form. To address this need a soil sampling and characterization program was initiated which makes use of a variety of standard analytical techniques coupled with state-of-the-art microscopy and spectroscopy techniques. Sample representativeness is evaluated through the development of conceptual models in an effort to identify and understand those geochemical processes governing the behavior of uranium in FEMP soils. Many of the initial results have significant implications for the design of soil treatment technologies for application at the FEMP.

  16. Soil contamination with radionuclides and potential remediation.

    PubMed

    Zhu, Y G; Shaw, G

    2000-07-01

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

  17. SYNOPSES OF FEDERAL DEMONSTRATIONS OF INNOVATIVE REMEDIATION TECHNOLOGIES

    EPA Science Inventory

    This collection of abstracts, compiled by the Federal Remediation Technology Roundtable, describes field demonstrations of innovative technologies to treat hazardous waste. The collection is intended to be an information resource for hazardous waste site project managers for asse...

  18. DEMONSTRATION BULLETIN STEAM ENHANCED REMEDIATION STEAM TECH ENVIRONMENTAL SERVICES, INC.

    EPA Science Inventory

    Steam Enhanced Remediation is a process in which steam is injected into the subsurface to recover volatile and semivolatile organic contaminants. It has been applied successfully to recover contaminants from soil and aquifers and at a fractured granite site. This SITE demonstra...

  19. 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.

  20. Testing amendments for remediation of military range contaminated soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  1. In situ soil remediation using electrokinetics

    SciTech Connect

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

    1994-11-01

    Electrokinetics is emerging as a promising technology for in situ soil remediation. This technique is especially attractive for Superfund sites and government operations which contain large volumes of contaminated soil. The approach uses an applied electric field to induce transport of both radioactive and hazardous waste ions in soil. The transport mechanisms include electroosmosis, electromigration, and electrophoresis. The feasibility of using electrokinetics to move radioactive {sup 137}Cs and {sup 60}Co at the Hanford Site in Richland, Washington, is discussed. A closed cell is used to provide in situ measurements of {sup 137}Cs and {sup 60}Co movement in Hanford soil. Preliminary results of ionic movement, along with the corresponding current response, are presented.

  2. 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

  3. In situ soil remediation: Bacteria or fungi?

    SciTech Connect

    Cutright, T.J.; Lee, S.

    1995-07-01

    Contamination of the environment is not a new problem. For most of recorded history, the unwanted byproducts of industrial and residential processes have been dumped into unlined pits or nearby streams. Although disposal techniques have greatly improved, significant quantities of hazardous materials are still being released to the environment via accidental spills and leaking underground storage tanks. One particular group of contaminants of critical environmental concern is polycyclic aromatic hydrocarbons (PAHs). PAH-contaminated sites typically cover large areas; therefore, the development of in situ remediation techniques such as bioremediation is strongly emphasized. In situations when inherent microorganisms are not capable of degrading the contaminants, foreign strains must be used. Bioremediation experiments were conducted to compare the remediation efficiencies of a bacteria and a fungus for an industrially PAH contaminated soil. Specifically, the use of three supplemental nutrient solutions were investigated in conjunction with the bacteria Achromobacter sp. and fungus Cunninghamella echinulata var. elegans.

  4. Cost studies of thermally enhanced in situ soil remediation technologies

    SciTech Connect

    Bremser, J.; Booth, S.R.

    1996-05-01

    This report describes five thermally enhanced technologies that may be used to remediate contaminated soil and water resources. The standard methods of treating these contaminated areas are Soil Vapor Extraction (SVE), Excavate & Treat (E&T), and Pump & Treat (P&T). Depending on the conditions at a given site, one or more of these conventional alternatives may be employed; however, several new thermally enhanced technologies for soil decontamination are emerging. These technologies are still in demonstration programs which generally are showing great success at achieving the expected remediation results. The cost savings reported in this work assume that the technologies will ultimately perform as anticipated by their developers in a normal environmental restoration work environment. The five technologies analyzed in this report are Low Frequency Heating (LF or Ohmic, both 3 and 6 phase AC), Dynamic Underground Stripping (DUS), Radio Frequency Heating (RF), Radio Frequency Heating using Dipole Antennae (RFD), and Thermally Enhanced Vapor Extraction System (TEVES). In all of these technologies the introduction of heat to the formation raises vapor pressures accelerating contaminant evaporation rates and increases soil permeability raising diffusion rates of contaminants. The physical process enhancements resulting from temperature elevations permit a greater percentage of volatile organic compound (VOC) or semi- volatile organic compound (SVOC) contaminants to be driven out of the soils for treatment or capture in a much shorter time period. This report presents the results of cost-comparative studies between these new thermally enhanced technologies and the conventional technologies, as applied to five specific scenarios.

  5. Soil amendment: a technique for soil remediation of lactofen.

    PubMed

    Mukherjee, Irani; Gopal, Madhuban; Das, T K

    2007-07-01

    Lactofen, a member of the diphenyl ether chemical family, shows great potential for the control of broadleaf weeds associated with leguminous crops. It presents a high degree of selectivity when applied post-emergence to soybean and peanut crops. This paper presents the persistence of lactofen under a soybean crop under various conditions, including without remediation techniques, under soil solarization with polyethene sheets, and soil solarization followed by straw amendment. The results indicate that dissipation is faster when using the soil solarization technique (set II) compared to no treatment (set I) and is further enhanced by tstraw amendment, where almost 90% dissipation was recorded (set III). The dissipation followed first-order kinetics with a half-life that varied from 30 to 10 days. The half-life of lactofen was 15 days in treatments of soil solarization and straw amendments alone, indicating that both techniques have to be used in combination to achieve successful remediation of soil. Use of biodegradable polythene/substitute material will make this process a popular technique and may also improve its commercial viability. PMID:17599224

  6. FEASIBILITY OF ELECTROKINETIC SOIL REMEDIATION IN HORIZONTAL LASAGNA CELLS

    EPA Science Inventory

    An integrated soil remediation technology called Lasagna has been developed that combines electrokinetics with treatment zones for use in low permeability soils where the rates of hydraulic and electrokinetic transport are too low to be useful for remediation of contaminants. The...

  7. Use of manure to remediate eroded hill top soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soils damaged by the dustbowl years can still be found across the Western Central Great Plains. Most of these soils have lost top soil rich in organic matter. Our objective was to determine best management practices for remediating these soils using beef manure as an organic amendment. In a field ...

  8. Ferritization treatment of copper in soil by electrokinetic remediation.

    PubMed

    Kimura, Tomoyuki; Takase, Ken-Ichi; Terui, Norifumi; Tanaka, Shunitz

    2007-05-17

    The usefulness of the combined use of the electrokinetic (EK) remediation and a ferrite treatment zone (FTZ) was demonstrated for a treatment of the contaminated soil with heavy metal ions. Copper ions in contaminated soil were transferred into the FTZ by the EK technology and were ferritized in this system. The distribution of copper in a migration chamber after EK treatment with FTZ for 48h showed the large difference in the total and eluted concentration of copper. This indicated that copper ions transferred by EK into the FTZ were ferritized there with ferrite reagent in soil alkalified by EK process. The copper-ferrite compound, which was not dissolved with diluted acid, was retained in the FTZ and accumulated there. The ratio of the ferritized amount of copper against total copper was 92% in the EK process with FTZ after 48 h. PMID:17374444

  9. Surface heating blanket for soil remediation

    SciTech Connect

    Van Egmond, C.F.; Carl, F.G. Jr.; Stegemeier, G.L.; Vinegar, H.J.

    1993-07-20

    A heater assembly is described for use in soil remediation comprising: a plurality of metallic support rods spaced parallel to each other; a continuous metallic strand spirally encircling adjacent ones of said support rods and forming rungs therearound, said rungs extending the length of said support rods, making low resistance contact therewith but being frictionally movable with respect thereto; an electric beater element located between and parallel to a selected pair of said support rods and between said rungs encircling said selected support rods, said heater being in low resistance frictional contact with said rungs along its length; a layer of insulation on top of said assembly; and an impermeable sheet placed on top of said insulation.

  10. WATER AS A REAGENT FOR SOIL REMEDIATION

    SciTech Connect

    Indira S. Jayaweera; Montserrat Marti-Perez; Jordi Diaz-Ferrero; Angel Sanjurjo

    2001-03-29

    SRI International is conducting experiments to develop and evaluate hydrothermal extraction technology or hot water extraction (HWE) technology for remediating petroleum-contaminated soils. Most current remediation practices either fail to remove the polycyclic aromatic hydrocarbons (PAHs) found in petroleum-contaminated sites, are too costly, or require the use of organic solvents at the expense of additional contamination and with the added cost of recycling solvents. Hydrothermal extraction offers the promise of efficiently extracting PAHs and other kinds of organics from contaminated soils at moderate temperatures and pressures, using only water and inorganic salts such as carbonate. SRI has conducted experiments to measure the solubility and rate of solubilization of selected PAHs (fluoranthene, pyrene, chrysene, 9,10-dimethylanthracene) in water using SRI's hydrothermal optical cell with the addition of varying amounts of sodium carbonate to evaluate the efficiency of the technology for removing PAHs from the soil. SRI data shows a very rapid increase in solubility of PAHs with increase in temperature in the range 25-275 C. SRI also measured the rate of solubilization, which is a key factor in determining the reactor parameters. SRI results for fluoranthene, pyrene, chrysene, and 9,10-dimethylanthracene show a linear relationship between rate of solubilization and equilibrium solubility. Also, we have found the rate of solubilization of pyrene at 275 C to be 6.5 ppm/s, indicating that the equilibrium solubilization will be reached in less than 3 min at 275 C; equilibrium solubility of pyrene at 275 C is 1000 ppm. Also, pyrene and fluoranthene appear to have higher solubilities in the presence of sodium carbonate. In addition to this study, SRI studied the rate of removal of selected PAHs from spiked samples under varying conditions (temperature, pore sizes, and pH). We have found a higher removal of PAHs in the presence of sodium carbonate in both sand and

  11. Lust remediation technologies. Part 2. Soil corrective action descriptions

    SciTech Connect

    Not Available

    1993-08-01

    Leaking underground storage tanks (LUSTs) have been recognized as a major potential source of ground water contamination in the U.S. Current state and federal regulations require the remediation of sites where the soil and/or ground water has been contaminated by leaking underground storage tanks. The document presents information on technologies for the remediation of contaminated soils at LUST sites. A companion volume, LUST Remediation Technologies: Part III - Ground Water Corrective Action Descriptions, presents information on technologies for the remediation of contaminated ground water at LUST sites.

  12. Using soil function evaluation in multi-criteria decision analysis for sustainability appraisal of remediation alternatives.

    PubMed

    Volchko, Yevheniya; Norrman, Jenny; Rosén, Lars; Bergknut, Magnus; Josefsson, Sarah; Söderqvist, Tore; Norberg, Tommy; Wiberg, Karin; Tysklind, Mats

    2014-07-01

    Soil contamination is one of the major threats constraining proper functioning of the soil and thus provision of ecosystem services. Remedial actions typically only address the chemical soil quality by reducing total contaminant concentrations to acceptable levels guided by land use. However, emerging regulatory requirements on soil protection demand a holistic view on soil assessment in remediation projects thus accounting for a variety of soil functions. Such a view would require not only that the contamination concentrations are assessed and attended to, but also that other aspects are taking into account, thus addressing also physical and biological as well as other chemical soil quality indicators (SQIs). This study outlines how soil function assessment can be a part of a holistic sustainability appraisal of remediation alternatives using multi-criteria decision analysis (MCDA). The paper presents a method for practitioners for evaluating the effects of remediation alternatives on selected ecological soil functions using a suggested minimum data set (MDS) containing physical, biological and chemical SQIs. The measured SQIs are transformed into sub-scores by the use of scoring curves, which allows interpretation and the integration of soil quality data into the MCDA framework. The method is demonstrated at a study site (Marieberg, Sweden) and the results give an example of how soil analyses using the suggested MDS can be used for soil function assessment and subsequent input to the MCDA framework. PMID:24529453

  13. 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...

  14. A mechanistic study of arsenate removal from artificially contaminated clay soils by electrokinetic remediation.

    PubMed

    Suzuki, Tasuma; Moribe, Mai; Okabe, Yohhei; Niinae, Masakazu

    2013-06-15

    Batch desorption experiments and bench-scale electrokinetic experiments were performed to elucidate the electrokinetic remediation mechanisms of arsenate from artificially contaminated kaolinite. The electrokinetic experiments in which a constant voltage was applied demonstrated that high soil pH favored arsenate remediation with respect to both the remediation time and electricity consumption. It was also demonstrated that applying a pulse voltage (1 h ON, 1 h OFF) significantly improved the electricity consumption efficiency when the soil pH was maintained at the initial value during the experiments; this trend was not observed when the soil pH was gradually increased from the cathode side. These electrokinetic experimental results, with the support of arsenate desorption data obtained from batch experiments, indicate that the remediation rate-limiting step varied with soil pH. When the soil pH was maintained at the initial value of 7.2 during the experiments, arsenate desorption was the remediation rate-limiting step rather than the migration of dissolved arsenate toward the anode. Conversely, when the cathode pH was not controlled and the soil pH was correspondingly increased gradually from the cathode side, the migration of hydroxyl and desorbed arsenate ions toward the anode played a more important role in the control of the overall remediation efficiency. PMID:23643955

  15. 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.

  16. Remediating soils: Designing biochars to meet the need

    EPA Science Inventory

    Biochar, the porous, carbon-rich product of pyrolysis, may provide an additional tool for remediating both metal and organic contaminated soils and for reducing other soil limitations. Soils contaminated with metals, organics or limited in some other way is a world-wide problem...

  17. [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

  18. Soil hydrologic characterization for modeling large scale soil remediation protocols

    NASA Astrophysics Data System (ADS)

    Romano, Nunzio; Palladino, Mario; Di Fiore, Paola; Sica, Benedetto; Speranza, Giuseppe

    2014-05-01

    In Campania Region (Italy), the Ministry of Environment identified a National Interest Priority Sites (NIPS) with a surface of about 200,000 ha, characterized by different levels and sources of pollution. This area, called Litorale Domitio-Agro Aversano includes some polluted agricultural land, belonging to more than 61 municipalities in the Naples and Caserta provinces. In this area, a high level spotted soil contamination is moreover due to the legal and outlaw industrial and municipal wastes dumping, with hazardous consequences also on the quality of the water table. The EU-Life+ project ECOREMED (Implementation of eco-compatible protocols for agricultural soil remediation in Litorale Domizio-Agro Aversano NIPS) has the major aim of defining an operating protocol for agriculture-based bioremediation of contaminated agricultural soils, also including the use of crops extracting pollutants to be used as biomasses for renewable energy production. In the framework of this project, soil hydrologic characterization plays a key role and modeling water flow and solute transport has two main challenging points on which we focus on. A first question is related to the fate of contaminants infiltrated from stormwater runoff and the potential for groundwater contamination. Another question is the quantification of fluxes and spatial extent of root water uptake by the plant species employed to extract pollutants in the uppermost soil horizons. Given the high variability of spatial distribution of pollutants, we use soil characterization at different scales, from field scale when facing root water uptake process, to regional scale when simulating interaction between soil hydrology and groundwater fluxes.

  19. Effects of aggressive remediation on soil properties and function

    NASA Astrophysics Data System (ADS)

    Switzer, Christine; Zihms, Stephanie; Pape, Andrew; Robson, Andrew; Knapp, Charles

    2013-04-01

    Aggressive remediation processes such as thermal desorption, smouldering, and chemical oxidiation remediation processes have significant promise to deliver substantial contaminant reduction in short periods of time, effecting as much as 95-99+% mass removal from non-aqueous phase liquid (NAPL) source zones. In situ thermal remediation exposes soils to temperatures of 100+°C for periods of weeks or months. In situ smouldering exposes soils to 600-1000+°C for hours to days. Chemical oxidation exposes soils to harsh oxidizing chemicals for weeks or months effecting reactive degradation of chemical contaminants but also surrounding soils. These processes have the potential to result in significant changes to the soil properties, particularly at the particle surface and grain interfaces. The dynamic effects of these changes have important implications in soil management practice. The mobilisation of soil nutrients may challenge rehabilitation or biological "polishing" after aggressive remediation. Plant germination and growth are inhibited and water dynamics are affected as well. Although permeability remains unaffected, infiltration is more rapid and capillary rise is reduced after smouldering remediation. Mobilisation of fines does not explain the change in infiltration and capillary rise; these effects persist after removal of the smaller half of the particle size distribution. Some separation of the soil column is observed in water infiltration after both thermal and smouldering remediation, indicating that erosion and subsidence are potential problems. These effects may be manifestations of subcritical water repellency. Based on the retention of capillary rise and lack of effects on other soil properties, the soil should be amenable to improvement measures. This presentation will place the effects of aggressive remediation into context within real soils and model materials.

  20. FEASIBILITY OF HYDRAULIC FRACTURING OF SOILS TO IMPROVE REMEDIAL ACTIONS

    EPA Science Inventory

    Hydraulic fracturing, a method of increasing fluid flow within the subsurface, should improve the effectiveness of several remedial techniques, including pump and treat, vapor extraction, bio-remediation, and soil-flushing. he technique is widely used to increase the yields of oi...

  1. GROUND WATER ISSUE: STEAM INJECTION FOR SOIL AND AQUIFER REMEDIATION

    EPA Science Inventory

    The purpose of this Issue Paper is to provide to those involved in assessing remediation technologies for specific sites basic technical information on the use of steam injection for the remediation of soils and aquifers that are contaminated by volatile or semivolatile organic c...

  2. Remediation case studies: In situ soil treatment technologies (soil vapor extraction, thermal processes). Volume 8

    SciTech Connect

    1998-09-01

    The case studies present available cost and performance information for full-scale remediation efforts. The studies contain varying levels of detail, reflecting the differences in the availability of data and information. The case studies in this volume describe 14 applications of soil vapor extraction (SVE) and in situ thermal processes. These include 10 full-scale and one pilot-scale SVE applications used to treat soil contaminated with chlorinated solvents and petroleum hydrocarbons. Three of these applications involved treatment or containment of both contaminated soil and groundwater through a combination of SVE, air sparging, groundwater extraction, and/or in situ bioremediation technologies. One case study describes a photolytic technology demonstrated for treatment of contaminated vapors from an SVE system. In addition, this volume describes two in situ thermal treatment applications, one used to recover free and residual coal tar, and one that was a demonstration of an in situ process to desorb PCBs from soil.

  3. VOCs in Non-Arid Soils Integrated Demonstration: Technology summary

    SciTech Connect

    Not Available

    1994-02-01

    The Volatile Organic Compounds (VOCs) in Non-Arid Soils Integrated Demonstration (ID) was initiated in 1989. Objectives for the ID were to test the integrated demonstration concept, demonstrate and evaluate innovative technologies/systems for the remediation of VOC contamination in soils and groundwater, and to transfer technologies and systems to internal and external customers for use in fullscale remediation programs. The demonstration brought together technologies from DOE laboratories, other government agencies, and industry for demonstration at a single test bed. The Savannah River Site was chosen as the location for this ID as the result of having soil and groundwater contaminated with VOCS. The primary contaminants, trichlorethylene and tetrachloroethylene, originated from an underground process sewer line servicing a metal fabrication facility at the M-Area. Some of the major technical accomplishments for the ID include the successful demonstration of the following: In situ air stripping coupled with horizontal wells to remediate sites through air injection and vacuum extraction; Crosshole geophysical tomography for mapping moisture content and lithologic properties of the contaminated media; In situ radio frequency and ohmic heating to increase mobility, of the contaminants, thereby speeding recovery and the remedial process; High-energy corona destruction of VOCs in the off-gas of vapor recovery wells; Application of a Brayton cycle heat pump to regenerate carbon adsorption media used to trap VOCs from the offgas of recovery wells; In situ permeable flow sensors and the colloidal borescope to determine groundwater flow; Chemical sensors to rapidly quantify chlorinated solvent contamination in the subsurface; In situ bioremediation through methane/nutrient injection to enhance degradation of contaminants by methanotrophic bateria.

  4. 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

  5. DEMONSTRATION BULLETIN: SOIL WASHING SYSTEM - BIOTROL, INC.

    EPA Science Inventory

    The three component technologies of the BioTrol Soil Washing System (BSWS). Tested in the SITE demonstration were a Soil Washer (SW), and Aqueous Treatment System (ATS), and a Slurry Bio-Reactor (SBR). The Soil Washer operates on the principle that a significant fraction of the...

  6. Laboratory Experiments on Electrochemical Remediation of the Environment Part 3: Microscale Electrokinetic Processing of Soils

    NASA Astrophysics Data System (ADS)

    Ibanez, Jorge G.; Singh, Mono M.; Pike, Ronald M.; Szafran, Zvi

    1998-05-01

    Electrochemical remediation of the environment is gaining widespread acceptance due to the mild conditions used, the cleanliness of the electron as a reagent, the easiness for automation, its versatility, etc. In this paper three phenomena are presented at the microscale level, originating from the application of an electric field to a simulated soil sample: a) Demonstration of metal ion migration, b) Demonstration of the creation and movement of an acidic and a basic front, and c) Demonstration of water movement through soil.

  7. In situ remediation technologies for mercury-contaminated soil

    DOE PAGESBeta

    He, Feng; Gao, Jie; Pierce, Eric; Strong, P. J.; Wang, Hailong; Liang, Liyuan

    2015-04-09

    A pollutant that poses significant risks to humans and the environment is mercury from anthropogenic activities. In soils, mercury remediation can be technically challenging and costly, depending on the subsurface mercury distribution, the types of mercury species, and the regulatory requirements. Our paper introduces the chemistry of mercury and its implications for in situ mercury remediation, which is followed by a detailed discussion of several in situ Hg remediation technologies in terms of applicability, cost, advantages, and disadvantages. The effect of Hg speciation on remediation performance, as well as Hg transformation during different remediation processes, was detailed. Thermal desorption, electrokinetic,more » and soil flushing/washing treatments are removal technologies that mobilize and capture insoluble Hg species, while containment, solidification/stabilization, and vitrification immobilize Hg by converting it to less soluble forms. We also discussed two emerging technologies, phytoremediation and nanotechnology, in this review.« less

  8. In situ remediation technologies for mercury-contaminated soil.

    PubMed

    He, Feng; Gao, Jie; Pierce, Eric; Strong, P J; Wang, Hailong; Liang, Liyuan

    2015-06-01

    Mercury from anthropogenic activities is a pollutant that poses significant risks to humans and the environment. In soils, mercury remediation can be technically challenging and costly, depending on the subsurface mercury distribution, the types of mercury species, and the regulatory requirements. This paper introduces the chemistry of mercury and its implications for in situ mercury remediation, which is followed by a detailed discussion of several in situ Hg remediation technologies in terms of applicability, cost, advantages, and disadvantages. The effect of Hg speciation on remediation performance, as well as Hg transformation during different remediation processes, was detailed. Thermal desorption, electrokinetic, and soil flushing/washing treatments are removal technologies that mobilize and capture insoluble Hg species, while containment, solidification/stabilization, and vitrification immobilize Hg by converting it to less soluble forms. Two emerging technologies, phytoremediation and nanotechnology, are also discussed in this review. PMID:25850737

  9. In situ remediation technologies for mercury-contaminated soil

    SciTech Connect

    He, Feng; Gao, Jie; Pierce, Eric; Strong, P. J.; Wang, Hailong; Liang, Liyuan

    2015-04-09

    A pollutant that poses significant risks to humans and the environment is mercury from anthropogenic activities. In soils, mercury remediation can be technically challenging and costly, depending on the subsurface mercury distribution, the types of mercury species, and the regulatory requirements. Our paper introduces the chemistry of mercury and its implications for in situ mercury remediation, which is followed by a detailed discussion of several in situ Hg remediation technologies in terms of applicability, cost, advantages, and disadvantages. The effect of Hg speciation on remediation performance, as well as Hg transformation during different remediation processes, was detailed. Thermal desorption, electrokinetic, and soil flushing/washing treatments are removal technologies that mobilize and capture insoluble Hg species, while containment, solidification/stabilization, and vitrification immobilize Hg by converting it to less soluble forms. We also discussed two emerging technologies, phytoremediation and nanotechnology, in this review.

  10. 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

  11. Uranium in Soils Integrated Demonstration: Technology summary, March 1994

    SciTech Connect

    Not Available

    1994-03-01

    A recent Pacific Northwest Laboratory (PNL) study identified 59 waste sites at 14 DOE facilities across the nation that exhibit radionuclide contamination in excess of established limits. The rapid and efficient characterization of these sites, and the potentially contaminated regions that surround them represents a technological challenge with no existing solution. In particular, the past operations of uranium production and support facilities at several DOE sites have occasionally resulted in the local contamination of surface and subsurface soils. Such contamination commonly occurs within waste burial sites, cribs, pond bottom sediments and soils surrounding waste tanks or uranium scrap, ore, tailings, and slag heaps. The objective of the Uranium In Soils Integrated Demonstration is to develop optimal remediation methods for soils contaminated with radionuclides, principally uranium (U), at DOE sites. It is examining all phases involved in an actual cleanup, including all regulatory and permitting requirements, to expedite selection and implementation of the best technologies that show immediate and long-term effectiveness specific to the Fernald Environmental Management Project (FEMP) and applicable to other radionuclide contaminated DOE sites. The demonstration provides for technical performance evaluations and comparisons of different developmental technologies at FEMP sites, based on cost-effectiveness, risk-reduction effectiveness, technology effectiveness, and regulatory and public acceptability. Technology groups being evaluated include physical and chemical contaminant separations, in situ remediation, real-time characterization and monitoring, precise excavation, site restoration, secondary waste treatment, and soil waste stabilization.

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

    PubMed

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

    2016-03-01

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

  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. PMID:22439580

  14. Fixed capital investments for the uranium soils integrated demonstration soil treatment technologies

    SciTech Connect

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

    1995-05-01

    The development of a nuclear industry in the United States required mining, milling, and fabricating a large variety of uranium products. One of these products was purified uranium metal which was used in the Savannah River and Hanford Site reactors. Most of this feed material was produced at the United States Department of Energy (DOE) facility formerly called the Feed Materials Production Center at Fernald, Ohio. During operation of this facility, soils became contaminated with uranium from a variety of sources. To address remediation and management of uranium-contaminated soils at sites owned by DOE, the Uranium Soils Integrated Demonstration (USID) Program was formed to evaluate and compare the versatility, efficiency, and economics of various technologies that may be combined into systems designed to characterize and remediate uranium contaminated soils. The USID Program has five major tasks in developing and demonstrating these technologies. Each must be able to (1) characterize the uranium in soil, (2) decontaminate or remove uranium from soil, (3) treat or dispose of resulting waste streams, (4) meet necessary state and federal regulations, and (5) meet performance assessment objectives. The role of the performance assessment objectives is to provide the information necessary to conduct evaluations of the technologies. These performance assessments provide the basis for selecting the optimum system for remediation of large areas contaminated with uranium. One of the performance assessment tasks is to address the economics of full-scale implementation of soil treatment technologies developed by the USID Program. The cost of treating contaminated soil is one of the criteria used in the decision-making process for selecting remedial alternatives.

  15. In-situ remediation system for groundwater and soils

    DOEpatents

    Corey, J.C.; Kaback, D.S.; Looney, B.B.

    1991-01-01

    The present invention relates to a system for in-situ remediation of contaminated groundwater and soil. In particular the present invention relates to stabilizing toxic metals in groundwater and soil. The United States Government has rights in this invention pursuant to Contract No. DE-AC09-89SR18035 between the US Department of Energy and Westinghouse Savannah River Company.

  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. Surfactant remediation field demonstration using a vertical circulation well

    SciTech Connect

    Knox, R.C.; Sabatini, D.A.; Harwell, J.H.; Brown, R.E.; West, C.C.; Blaha, F.; Griffin, C.

    1997-11-01

    A field demonstration of surfactant-enhanced solubilization was completed in a shallow unconfined aquifer located at a Coast Guard Station in Traverse City, Michigan. The primary objectives of the study were: (1) to assess the ability of the vertical circulation well (VCW) system for controlling chemical extractants added to the subsurface; and (2) to assess the behavior of the surfactant solution in the subsurface, with a goal of maximum surfactant recovery. A secondary objective was to demonstrate enhanced removal of PCE and recalcitrant components of a jet fuel. The analytical results showed that the surfactant increased the contaminant mass extracted by 40-fold and 90-fold for the PCE and jet fuel constituents, respectively. The surfactant solution demonstrated minimal sorption (retardation) and did not precipitate in the subsurface formation. In addition, the VCW system was able to capture in excess of 95% of the injected surfactant solution. Additional field testing and full-scale implementation of surfactant-enhanced subsurface remediation should be performed.

  18. Integrated technologies for expedited soil and groundwater remediation

    SciTech Connect

    Lewis, R.; Wellman, D.

    1996-12-01

    A fast-track and economic approach was necessary to meet the needs of a property transfer agreement and to minimize impact to future usage of a site in the Los Angeles Basin. Woodward-Clyde responded by implementing site investigation, remedial action plan preparation for soil and groundwater, and selection and installation of remedial alternatives in an aggressive schedule of overlapped tasks. Assessment of soil and groundwater was conducted at the site, followed by design and construction of remediation systems. This phase of activity was completed within 2 years. Soil and groundwater were found to be impacted by chlorinated solvents and petroleum hydrocarbons. A vapor extraction system (2,000 scfm capacity) was installed for soil remediation, and an innovative air sparging system was installed for cost effective groundwater cleanup. A bioventing system was also applied in selected areas. The vapor extraction wellfield consists of 26 extraction and monitoring well points, with multiple screened casings. The air sparging wellfield consists of 32 sparging wells with a designed maximum flow of 400 scfm. The systems began operation in 1993, and have resulted in the estimated removal of approximately 30,000 pounds of contaminants, or about 90% of the estimated mass in place. The combined vapor extraction/air sparging system is expected to reduce the time for on-site groundwater remediation from 1/3 to 1/6 the time when compared to the conventional pump and treat method for groundwater remediation.

  19. In-situ demonstration of radio-frequency enhanced chlorinated hydrocarbon remediation

    SciTech Connect

    Kasevich, R.S.; Price, S.L.; Faust, D.L.; Jarosch, T.R.

    1994-06-01

    This paper discusses the results of a successful demonstration of radio frequency (RF) heating for enhanced chlorinated hydrocarbon remediation at the M-Area Seepage Basin of the Department of Energy`s Savannah River Site. RF heating was integrated with soil vapor extraction (SVE) to enhance the release of residual volatile chlorinated hydrocarbons which are concentrated in low permeable clay lenses in the unsaturated zone. Participants in this effort consisted of the Westinghouse Savannah River Technology Center; the Westinghouse Science and Technology Center (Pittsburgh, PA); and KAI Technologies, Inc. which provided the RF technology. Additionally, a better understanding of RF heating technology is gained through a description of the RF heating system.

  20. Advanced multivariate analysis to assess remediation of hydrocarbons in soils.

    PubMed

    Lin, Deborah S; Taylor, Peter; Tibbett, Mark

    2014-10-01

    Accurate monitoring of degradation levels in soils is essential in order to understand and achieve complete degradation of petroleum hydrocarbons in contaminated soils. We aimed to develop the use of multivariate methods for the monitoring of biodegradation of diesel in soils and to determine if diesel contaminated soils could be remediated to a chemical composition similar to that of an uncontaminated soil. An incubation experiment was set up with three contrasting soil types. Each soil was exposed to diesel at varying stages of degradation and then analysed for key hydrocarbons throughout 161 days of incubation. Hydrocarbon distributions were analysed by Principal Coordinate Analysis and similar samples grouped by cluster analysis. Variation and differences between samples were determined using permutational multivariate analysis of variance. It was found that all soils followed trajectories approaching the chemical composition of the unpolluted soil. Some contaminated soils were no longer significantly different to that of uncontaminated soil after 161 days of incubation. The use of cluster analysis allows the assignment of a percentage chemical similarity of a diesel contaminated soil to an uncontaminated soil sample. This will aid in the monitoring of hydrocarbon contaminated sites and the establishment of potential endpoints for successful remediation. PMID:25028320

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

    PubMed

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

    2014-01-01

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

  2. Overview of Green and Sustainable Remediation for Soil and Groundwater Remediation - 12545

    SciTech Connect

    Simpkin, Thomas J.; Favara, Paul

    2012-07-01

    Making remediation efforts more 'sustainable' or 'green' is a topic of great interest in the remediation community. It has been spurred on by Executive Orders from the White House, as well as Department of Energy (DOE) sustainability plans. In private industry, it is motivated by corporate sustainability goals and corporate social responsibility. It has spawned new organizations, areas of discussion, tools and practices, and guidance documents around sustainable remediation or green remediation. Green remediation can be thought of as a subset of sustainable remediation and is mostly focused on reducing the environmental footprint of cleanup efforts. Sustainable remediation includes both social and economic considerations, in addition to environmental. Application of both green and sustainable remediation (GSR) may involve two primary activities. The first is to develop technologies and alternatives that are greener or more sustainable. This can also include making existing remediation approaches greener or more sustainable. The second is to include GSR criteria in the evaluation of remediation alternatives and strategies. In other words, to include these GSR criteria in the evaluation of alternatives in a feasibility study. In some cases, regulatory frameworks allow the flexibility to include GSR criteria into the evaluation process (e.g., state cleanup programs). In other cases, regulations allow less flexibility to include the evaluation of GSR criteria (e.g., Comprehensive Environmental Response Compensation, and Liability Act (CERCLA)). New regulatory guidance and tools will be required to include these criteria in typical feasibility studies. GSR provides a number of challenges for remediation professionals performing soil and groundwater remediation projects. Probably the most significant is just trying to stay on top of the ever changing landscape of products, tools, and guidance documents coming out of various groups, the US EPA, and states. However, this

  3. GROUNDWATER AND SOIL REMEDIATION USING ELECTRICAL FIELD

    EPA Science Inventory

    Enhancements of contaminants removal and degradation in low permeability soils by electrical fields are achieved by the processes of electrical heating, electrokinetics, and electrochemical reactions. Electrical heating increases soil temperature resulting in the increase of cont...

  4. 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.

  5. 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, ...

  6. INNOVATIVE FOSSIL FUEL FIRED VITRIFICATION TECHNOLOGY FOR SOIL REMEDIATION

    SciTech Connect

    J. Hnat; L.M. Bartone; M. Pineda

    2001-07-13

    This Summary Report summarizes the progress of Phases 3, 3A and 4 of a waste technology Demonstration Project sponsored under a DOE Environmental Management Research and Development Program and administered by the U.S. Department of Energy National Energy Technology Laboratory-Morgantown (DOE-NETL) for an ''Innovative Fossil Fuel Fired Vitrification Technology for Soil Remediation''. The Summary Reports for Phases 1 and 2 of the Program were previously submitted to DOE. The total scope of Phase 3 was to have included the design, construction and demonstration of Vortec's integrated waste pretreatment and vitrification process for the treatment of low level waste (LLW), TSCA/LLW and mixed low-level waste (MLLW). Due to funding limitations and delays in the project resulting from a law suit filed by an environmental activist and the extended time for DOE to complete an Environmental Assessment for the project, the scope of the project was reduced to completing the design, construction and testing of the front end of the process which consists of the Material Handling and Waste Conditioning (MH/C) Subsystem of the vitrification plant. Activities completed under Phases 3A and 4 addressed completion of the engineering, design and documentation of the Material Handling and Conditioning System such that final procurement of the remaining process assemblies can be completed and construction of a Limited Demonstration Project be initiated in the event DOE elects to proceed with the construction and demonstration testing of the MH/C Subsystem.

  7. 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

  8. 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

  9. [Optimization of electrode configuration in soil electrokinetic remediation].

    PubMed

    Liu, Fang; Fu, Rong-Bing; Xu, Zhen

    2015-02-01

    Electric field distributions of several different electrode configurations in non-uniform electric field were simulated using MATLAB software, and the electrokinetic remediation device was constructed according to the best electrode configuration. The changes of soil pH and heavy metal residues in different parts of the device during the electrokinetic remediation were also studied. The results showed that, in terms of the effectiveness of the electric field strength, the square (1-D-1) and hexagonal (2-D-3) were the optimal electrode configurations for one-dimensional and two-dimensional respectively and the changes of soil pH, the removal of heavy metals and the distribution of electric field were closely related to one another. An acidic migration band, which could prevent premature precipitation of heavy metals to a certain extent and promote electrokinetic removal of heavy metals, was formed gradually along with the remediation in the whole hexagon device when the cathodic pH was controlled during the remediation of the four cationic metallic ions, Cd2+, Ni2+, Pb2+ and Cu2+. After 480-hour remediation, the total removals of Cd, Ni, Pb and Cu were 86.6%, 86.2%, 67.7% and 73.0%, respectively. Remediation duration and replacement frequency of the electrodes could be adjusted according to the repair target. PMID:26031098

  10. Bioventing vs. prepared beds for remediation of petroleum contaminated soil

    SciTech Connect

    Hazen, T.C.; Lombard, K.H.; Kastner, J.R.

    1996-10-01

    Bioventing is an in situ biostimulation technique that has become extremely popular recently for remediation of near-surface sediment (soil) contaminated with petroleum products. Prepared Bed bioremediation of petroleum contaminated soil involves the use of a centralized controlled above ground facility that uses contained land-farming techniques. Several sites at the U.S. DOE Savannah River Site have been evaluated and remediated using these two technologies. The characterization cost, capital costs, safety, implementation time, remediation rate, monitoring requirements, final disposition requirements, regulatory requirements, and public acceptance make these techniques better then any other conventional technology, e.g. incineration, and make it difficult to decide which of the two is the best alternative. New rapid site characterization and treatability techniques e.g. laser induced fluorescence and microrespirometry, have allowed better decisions as to which of these two technologies is the most appropriate for a given site.

  11. Electroosmosis remediation of DNAPLS in low permeability soils

    SciTech Connect

    Ho, S V.

    1996-08-01

    Electroosmosis is the movement of water through a soil matrix induced by a direct current (DC) electric field. The technique has been used since the 1930s for dewatering and stabilizing fine-grained soils. More recently, electroosmosis has been considered as an in-situ method for soil remediation in which water is injected into the soil at the anode region to flush the contaminants to the cathode side for further treatment or disposal. The major advantage of electroosmosis is its inherent ability to move water uniformly through clayey, silty soils at 100 to 1000 times faster than attainable by hydraulic means, and with very low energy usage. Drawbacks of electroosmosis as a stand-alone technology include slow speed, reliance on solubilizing the contaminants into the groundwater for removal, potentially an unstable process for long term operation, and necessary additional treatment and disposal of the collected liquid. Possible remediation applications of electroosmosis for DNAPLs would be primarily in the removal of residual DNAPLs in the soil pores by electroosmotic flushing. The future of electroosmosis as a broad remedial method lies in how well it can be coupled with complementary technologies. Examples include combining electroosmosis with vacuum extraction, with surfactant usage to deal with non-aqueous phase liquids (NAPLs) through enhanced solubilization or mobilization, with permeability enhancing methods (hydrofracturing, pneumatic fracturing, etc.) to create recovery zones, and with in-situ degradation zones to eliminate aboveground treatment. 33 refs., 1 fig., 1 tab.

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

    EPA Science Inventory

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

  13. 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.

  14. 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.

  15. FEASIBILITY OF HYDRAULIC FRACTURING OF SOILS TO IMPROVE REMEDIAL ACTIONS

    EPA Science Inventory

    Hydraulic fracturing, a technique commonly used to increase the yields of oil wells, could improve the effectiveness of several methods of in situ remediation. This project consisted of laboratory and field tests in which hydraulic fractures were created in soil. Laboratory te...

  16. Arsenic chemistry and remediation in Hawaiian soils.

    PubMed

    Hue, Nguyen V

    2013-01-01

    Past use of arsenical pesticides has resulted in elevated levels of arsenic (As) in some Hawaiian soils. Total As concentrations of 20-100 mg/kg are not uncommon, and can exceed 900 mg/kg in some lands formerly planted with sugarcane. With high contents of amorphous aluminosilicates and iron oxides in many Hawaii's volcanic ash-derived Andisols, a high proportion (25-30%) of soil As was associated with either these mineral phases or with organic matter. Less than 1% of the total As was water soluble or exchangeable. Furthermore, the soils can sorb As strongly: the addition of 1000 mg/kg as As (+5) resulted in only between 0.03 and 0.30 mg/L As in soil solution. In contrast, soils having more crystalline minerals (e.g., Oxisols) sorb less As and thus often contain less As. Phosphate fertilization increases As bioaccessibility, whereas the addition of Fe(OH)3 decreases it. Brake fern (Pteris vittata L.) can be used to remove some soil As. Concentrations of As in fronds varied on average from 60 mg/kg when grown on a low-As Oxisol to 350 mg/kg when grown on a high-As Andisol. Ratios of leaf As to CaCl2-extractable soil As were 12 and 222 for the Oxisol and Andisol, respectively. PMID:23487989

  17. Ammonium citrate as enhancement for electrodialytic soil remediation and investigation of soil solution during the process.

    PubMed

    Dias-Ferreira, Celia; Kirkelund, Gunvor M; Ottosen, Lisbeth M

    2015-01-01

    Seven electrodialytic experiments were conducted using ammonium citrate as enhancing agent to remediate copper and chromium-contaminated soil from a wood-preservation site. The purpose was to investigate the effect of current density (0.2, 1.0 and 1.5 mA cm(-2)), concentration of enhancing agent (0.25, 0.5 and 1.0 M) and remediation times (21, 42 and 117 d) for the removal of Cu and Cr from a calcareous soil. To gain insight on metal behavior, soil solution was periodically collected using suction cups. It was seen that current densities higher than 1.0 mA cm(-2) did not increase removal and thus using too high current densities can be a waste of energy. Desorption rate is important and both remediation time and ammonium citrate concentration are relevant parameters. It was possible to collect soil solution samples following an adaptation of the experimental set-up to ensure continuous supply of ammonium citrate to the soil in order to keep it saturated during the remediation. Monitoring soil solution gives valuable information on the evolution of remediation and helps deciding when the soil is remediated. Final concentrations in the soil ranged from 220 to 360 mg Cu kg(-1) (removals: 78-86%) and 440-590 mg Cr kg(-1) (removals: 35-51%), being within the 500 mg kg(-1) limit for a clean soil only for Cu. While further optimization is still required for Cr, the removal percentages are the highest achieved so far, for a real Cu and Cr-contaminated, calcareous soil. The results highlight EDR potential to remediate metal polluted soils at neutral to alkaline pH by choosing a good enhancement solution. PMID:25240953

  18. Operable Unit 3-13, Group 3, Other Surface Soils Remediation Sets 4-6 (Phase II) Remedial Design/Remedial Action Work Plan

    SciTech Connect

    D. E. Shanklin

    2006-06-01

    This Remedial Design/Remedial Action Work Plan provides the framework for defining the remedial design requirements, preparing the design documentation, and defining the remedial actions for Waste Area Group 3, Operable Unit 3-13, Group 3, Other Surface Soils, Remediation Sets 4-6 (Phase II) located at the Idaho Nuclear Technology and Engineering Center at the Idaho National Laboratory. This plan details the design developed to support the remediation and disposal activities selected in the Final Operable Unit 3-13, Record of Decision.

  19. Demonstration testing and evaluation of in situ soil heating. Revision 1, Demonstration system design

    SciTech Connect

    Dev, H.

    1994-08-16

    Over the last nine years IIT Research Institute (IITRI) has been developing and testing the in situ heating and soil decontamination process for the remediation of soils containing hazardous organic contaminants. In this process the soil is heated in situ using electrical energy. The contaminants are removed from the soil due to enhanced vaporization, steam distillation and stripping. The vaporized contaminants, water vapor and air are recovered from the heated zone by means of a vacuum manifold system which collects gases from below surface as well as from the soil surface. A vapor barrier is used to prevent fugitive emissions of the contaminants and to control air infiltration to minimize dilution of the contaminant gases and vapors. The recovered gases and vapors are conveyed to an on site vapor treatment system for the clean up of the vent gases. Electrical energy is applied to the soil by forming an array of electrodes in the soil which are electrically interconnected and supplied with power. The electrodes are placed in drilled bore holes which are made through the contaminated zone. There are two versions of the in situ heating and soil treatment process: the f irst version is called the In Situ Radio Frequency (RF) Soil Decontamination Process and the second version is called the In Situ Electromagnetic (EM) Soil Decontamination Process. The first version, the RF Process is capable of heating the soil in a temperature range of 100{degrees} to 400{degrees}C. The soil temperature in the second version, the EM Process, is limited to the boiling point of water under native conditions. Thus the soil will be heated to a temperature of about 85{degrees} to 95{degrees}C. In this project IITRI will demonstrate the EM Process for in situ soil decontamination at K-25 Site due to the fact that most of the contaminants of concern are volatile organics which can be removed by heating the soil to a temperature range of 85{degrees} to 95{degrees}C.

  20. Use of plant and earthworm bioassays to evaluate remediation of soil from a site contaminated with polychlorinated biphenyls

    SciTech Connect

    Meier, J.R.; Chang, L.W.; Meckes, M.C.; Smith, M.K.; Jacobs, S.; Torsella, J.

    1997-05-01

    Soil from a site heavily contaminated with polychlorinated biphenyls (PCBs) was treated with a pilot-scale, solvent extraction technology. Bioassays in earthworms and plants were used to examine the efficacy of the remediation process for reducing the toxicity of the soil. The earthworm toxicity bioassays were the 14-d survival test and 21-d reproduction test, using Lumbricus terrestris and Eisenia fetida andrei. The plant bioassays included phytotoxicity tests for seed germination and root elongation in lettuce and oats, and a genotoxicity test (anaphase aberrations) in Allium cepa (common onion). Although the PCB content of the soil was reduced by 99% (below the remediation goal), toxicity to earthworm reproduction remained essentially unchanged following remediation. Furthermore, phytotoxicity and genotoxicity were higher for the remediated soil compared to the untreated soil. The toxicity remaining after treatment appeared to be due to residual solvent introduced during the remediation process, and/or to heavy metals or other inorganic contaminants not removed by the treatment. Mixture studies involving isopropanol and known toxicants indicated possible synergistic effects of the extraction solvent and soil contaminants. The toxicity in plants was essentially eliminated by a postremediation, water-rinsing step. These results demonstrate a need for including toxicity measurements in the evaluation of technologies used in hazardous waste site remediations, and illustrate the potential value of such measurements for making modifications to remediation processes.

  1. Characterization and remediation of soils contaminated with uranium.

    PubMed

    Gavrilescu, Maria; Pavel, Lucian Vasile; Cretescu, Igor

    2009-04-30

    Environmental contamination caused by radionuclides, in particular by uranium and its decay products is a serious problem worldwide. The development of nuclear science and technology has led to increasing nuclear waste containing uranium being released and disposed in the environment. The objective of this paper is to develop a better understanding of the techniques for the remediation of soils polluted with radionuclides (uranium in particular), considering: the chemical forms of uranium, including depleted uranium (DU) in soil and other environmental media, their characteristics and concentrations, and some of the effects on environmental and human health; research issues concerning the remediation process, the benefits and results; a better understanding of the range of uses and situations for which each is most appropriate. The paper addresses the main features of the following techniques for uranium remediation: natural attenuation, physical methods, chemical processes (chemical extraction methods from contaminated soils assisted by various suitable chelators (sodium bicarbonate, citric acid, two-stage acid leaching procedure), extraction using supercritical fluids such as solvents, permeable reactive barriers), biological processes (biomineralization and microbial reduction, phytoremediation, biosorption), and electrokinetic methods. In addition, factors affecting uranium removal from soils are furthermore reviewed including soil characteristics, pH and reagent concentration, retention time. PMID:18771850

  2. 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.

  3. Medium temperature thermal desorption soil remediation case study - Selfridge Air National Guard Base, Mt. Clemens, Michigan

    SciTech Connect

    Flemingloss, K. )

    1994-08-01

    Carlo Environmental Technologies, Inc., (CET) was contracted by the Selfridge Air National Guard base (SANG) to remove an abandoned underground storage tank (UST) farm and remediate the contaminated soil using thermal desorption technology. The first phase of this project was to remove fourteen 25,000 gal underground storage tanks that had been installed during the 1930's, including all ancillary equipment at the facility. The USTs had been used to store aviation fuels, including both av-gas and jet fuels. The tank-removal project disclosed over 5000 yd[sup 3] of contaminated soil in the tank excavation pit, and excavation continued until analytical sampling demonstrated that the perimeter was within the Michigan Department of Natural Resources (MDNR) Act 307 Type B cleanup criteria (state superfund act). The contaminated soil was trucked to a remote location on the base property for the thermal remediation. CET employed its Cedarapids 64MT thermal desorption plant to treat the contaminated soils from the tank removal site. These soils were predominantly clays, and the contamination included BTEX compounds up to 5 parts per million (ppm), and PNA compounds per 100 ppm. The medium temperature thermal desorption process, which heats the contaminated soil to approximately 850[degrees]F was successful in removing BTEX and PNA contamination from the soil (to levels below MDNR Type B cleanup criteria). The vapor stream from the desorption process was then filtered to minimize particulate emissions, and the contaminant compounds were then destroyed in the thermal oxidizer section of the process, at temperatures up to 1800[degrees]F. The remediated soil was returned to the original excavation as clean compacted fill material. With the use of the thermal desorption technology, CET remediated the site to MDNR cleanup standards, recycled the soils from the site, and eliminated off-site disposal liability for SANG.

  4. REMEDIATION OF PCB IN CONTAMINATED SOIL

    EPA Science Inventory

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

  5. 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...

  6. Remediation of Sucarnoochee soil by agglomeration with fine coal

    SciTech Connect

    Narayanan, P.S.; Arnold, D.W.; Rahnama, M.B. )

    1994-01-01

    Fine-sized Blue Creek coal was used to remove high molecular weight hydrocarbons from Sucarnoochee soil, a fine-sized high-organic soil. Fine coal in slurry form was blended with Sucarnoochee soil contaminated with 15.0% by wt of crude oil, and agglomerates were removed in a standard flotation cell. Crude oil in the remediated soil was reduced from the original 15.0% to less than a tenth of a wt% by a two-step process. Oil removal of approx. 99.3% was obtained. An added benefit was that the low-grade coal used in the process was simultaneously upgraded. The final level of cleaning was not affected by initial oil concentration. The process compared favorably with a hot water wash technique used to recovery oils from contaminated soil.

  7. Surfactant enhanced electrokinetic remediation of DDT from soils.

    PubMed

    Karagunduz, Ahmet; Gezer, Aras; Karasuloglu, Gulden

    2007-10-15

    Electrokinetic remediation has been investigated extensively as one of the noble technologies in remediation of metal contaminated soils. However, its applications in remediation of organic contaminants have been limited due to low solubilities of organics in water. In addition, most organic contaminants are non-ionic and therefore, they are not mobile under electrical field. The use of surfactants may increase the remediation efficiency by increasing the solubility of organics. Significant fraction of organics associated with soil, can be transferred to micellar phase, which then can be transported toward either cathode or anode, depending on the ionic group of surfactants. In this study, the removal of hydrophobic organic contaminants from a soil using electrokinetic method was investigated in the presence of surfactants. A nonionic surfactant, Tween 80, and an anionic surfactant, SDBS, were used in the experiments. DDT was chosen as the model organic contaminant. Phase distribution studies and column experiments were conducted. It was found that both Tween 80 and SDBS had similar solubilization potentials for DDT. It was also shown that the aqueous DDT mass could reach from 0.01 to 13% of the total mass in the presence of 7500 mg/L of SDBS. No significant movement of DDT was observed when Tween 80 was used in the column experiments. This was attributed to low rates of electroosmotic flows and strong interaction of Tween 80 with the soil. The amount of surfactant was not enough to mobilize DDT significantly in the column studies. On the other hand, electrokinetic transport with SDBS yielded much better results. DDT transport toward the anode within the negatively charged micelles overcame the opposite electrosmotic flow. This was attributed to the lower degree of interaction between the soil and SDBS, and the electrokinetic transport of negatively charged micelles. PMID:17706747

  8. INNOVATIVE FOSSIL FUEL FIRED VITRIFICATION TECHNOLOGY FOR SOIL REMEDIATION

    SciTech Connect

    J. Hnat; L.M. Bartone; M. Pineda

    2001-10-31

    This Final Report summarizes the progress of Phases 3,3A and 4 of a waste technology Demonstration Project sponsored under a DOE Environmental Management Research and Development Program and administered by the U.S. Department of Energy National Energy Technology Laboratory-Morgantown (DOE-NETL) for an ''Innovative Fossil Fuel Fired Vitrification Technology for Soil Remediation''. The Summary Reports for Phases 1 and 2 of the Program were previously submitted to DOE. The total scope of Phase 3 was to have included the design, construction and demonstration of Vortec's integrated waste pretreatment and vitrification process for the treatment of low level waste (LLW), TSCA/LLW and mixed low-level waste (MLLW). Due to funding limitations and delays in the project resulting from a law suit filed by an environmental activist and the extended time for DOE to complete an Environmental Assessment for the project, the scope of the project was reduced to completing the design, construction and testing of the front end of the process which consists of the Material Handling and Waste Conditioning (MH/C) Subsystem of the vitrification plant. Activities completed under Phases 3A and 4 addressed completion of the engineering, design and documentation of the MH/C System such that final procurement of the remaining process assemblies can be completed and construction of a Limited Demonstration Project be initiated in the event DOE elects to proceed with the construction and demonstration testing of the MH/C Subsystem. Because of USEPA policies and regulations that do not require treatment of low level or low-level/PCB contaminated wastes, DOE terminated the project because there is no purported need for this technology.

  9. Assessment of the Use of Natural Materials for the Remediation of Cadmium Soil Contamination

    PubMed Central

    de O. Pinto, Tatiana; García, Andrés C.; Guedes, Jair do N.; do A. Sobrinho, Nelson M. B.; Tavares, Orlando C. H.

    2016-01-01

    Rice plants accumulate cadmium (Cd2+) within the grain, increasing the danger of human exposure. Natural materials have been used in soil remediation, but few studies have examined the risks (based on the bioavailability of these metals to plants) of using these materials, so the practice remains controversial. In the present study, we evaluated the effectiveness of biochar produced from sugarcane bagasse, vermicompost (VC), vermicompost solid residue (VCR) and humin for remediation of Cd2+-contaminated soils. We characterized the interactions between these materials and Cd2+ and evaluated their capacity to alter Cd2+ availability to rice plants. Our results show that under the conditions in this study, biochar and humin were not effective for soil remediation. Although biochar had high Cd2+ retention, it was associated with high Cd2+ bioavailability and increased Cd2+ accumulation in rice plants. VC and VCR had high Cd2+ retention capacity as well as low Cd2+ availability to plants. These characteristics were especially notable for VCR, which was most effective for soil remediation. The results of our study demonstrate that in the tested materials, the bioavailability of Cd2+ to plants is related to their structural characteristics, which in turn determine their retention of Cd2+. PMID:27341440

  10. Assessment of the Use of Natural Materials for the Remediation of Cadmium Soil Contamination.

    PubMed

    de O Pinto, Tatiana; García, Andrés C; Guedes, Jair do N; do A Sobrinho, Nelson M B; Tavares, Orlando C H; Berbara, Ricardo L L

    2016-01-01

    Rice plants accumulate cadmium (Cd2+) within the grain, increasing the danger of human exposure. Natural materials have been used in soil remediation, but few studies have examined the risks (based on the bioavailability of these metals to plants) of using these materials, so the practice remains controversial. In the present study, we evaluated the effectiveness of biochar produced from sugarcane bagasse, vermicompost (VC), vermicompost solid residue (VCR) and humin for remediation of Cd2+-contaminated soils. We characterized the interactions between these materials and Cd2+ and evaluated their capacity to alter Cd2+ availability to rice plants. Our results show that under the conditions in this study, biochar and humin were not effective for soil remediation. Although biochar had high Cd2+ retention, it was associated with high Cd2+ bioavailability and increased Cd2+ accumulation in rice plants. VC and VCR had high Cd2+ retention capacity as well as low Cd2+ availability to plants. These characteristics were especially notable for VCR, which was most effective for soil remediation. The results of our study demonstrate that in the tested materials, the bioavailability of Cd2+ to plants is related to their structural characteristics, which in turn determine their retention of Cd2+. PMID:27341440

  11. Biochar and the remediation of soil micropollutants

    NASA Astrophysics Data System (ADS)

    Brennan, A.; Switzer, C.

    2012-04-01

    Persistent Organic Pollutants (POPs) present a globally significant problem in soil and water management due to their recalcitrance, tendency to bioaccumulate and their suspected or confirmed effects on human health. Biochar, defined as biomass pyrolysed in the absence of oxygen, has strong potential for the long-term sequestration of POPs that could otherwise be mobilised into ground and surface waters and contaminate soil and sediment matrices. The initial hypothesis is that biochar derived from green waste materials represents an effective means for sequestering these contaminants. The present work is investigating the potential of biochar to sequester POPs through adsorption isotherm sorption experiments, with current focuses being biochar material characterisation and contaminant behaviour. Contaminants of interest are polycyclic aromatic hydrocarbons (PAHs) as well as emerging contaminants of concern such as hormones and other micropollutants. Preliminary adsorption studies suggest that biochar shows significant promise for contaminant removal. Desorption studies address important questions that remain about long-term contaminant sequestration and potential remobilisation via fine particles and leachate from the biochar. The amounts of fine particles and leachate associated with each biochar are linked to the source material and pyrolysis process conditions used to create it. This work is attempting to establish a mass balance around the soil to determine the sequestration potential of a range of biochars. Analysis of contaminant concentrations is being carried out by GC-MS and HPLC. The ultimate aim of this work is to define the conditions where biochar and biochar-amended soils are able to effectively sequester trace levels of contaminants.

  12. Electrokinetic remediation of organochlorines in soil: enhancement techniques and integration with other remediation technologies.

    PubMed

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

    2012-06-01

    Electrokinetic remediation has been increasingly used in soils and other matrices for numerous contaminants such as inorganic, organic, radionuclides, explosives and their mixtures. Several strategies were tested to improve this technology effectiveness, namely techniques to solubilize contaminants, control soil pH and also couple electrokinetics with other remediation technologies. This review focus in the experimental work carried out in organochlorines soil electroremediation, aiming to systemize useful information to researchers in this field. It is not possible to clearly state what technique is the best, since experimental approaches and targeted contaminants are different. Further research is needed in the application of some of the reviewed techniques. Also a number of technical and environmental issues will require evaluation for full-scale application. Removal efficiencies reported in real contaminated soils are much lower than the ones obtained with spiked kaolinite, showing the influence of other factors like aging of the contamination and adsorption to soil particles, resulting in important challenges when transferring technologies into the field. PMID:22386462

  13. 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.

  14. Sour gas plant remediation technology research and demonstration project, Task 7.53. Topical report, January--December 1993

    SciTech Connect

    Stepan, D.J.; Kuehnel, V.; Schmit, C.R.

    1994-02-01

    Recognizing the potential impacts of sour gas plant operations on the subsurface environment, the Canadian Association of Petroleum Producers (CAPP) and Environment Canada initiated a multiphase study focusing on research related to the development and demonstration of remedial technologies for soil and groundwater contamination at these facilities. Research performed under this project was designed to supplement and be coordinated with research activities being conducted at an operational sour gas plant located in Rocky Mountain House, Alberta, Canada. These research tasks included hydrogeological site characterization, subsurface contaminant characterization, ex situ treatment of groundwater, and subsurface remediation of residual contamination in the unsaturated zone. Ex situ treatment of groundwater included evaluations of air stripping, steam stripping, advanced oxidation, and biological treatment, as well as the development of an artificial freeze crystallization process. Soil vapor extraction was evaluated as a technique to address residual contamination in the unsaturated zone.

  15. Remediation of PCB contaminated soils using iron nano-particles.

    PubMed

    Varanasi, Patanjali; Fullana, Andres; Sidhu, Sukh

    2007-01-01

    In this study, iron nano-particles were used to remediate PCB contaminated soil and an attempt was made to maximize PCB destruction in each treatment step. The results show that nano-particles do aid in the dechlorination process and high PCB destruction efficiencies can be achieved. The destruction efficiency during the preliminary treatment (mixing of soil and iron nano-particles in water) can be increased by increasing the water temperature. The maximum thermal destruction (pyrolysis/combustion of soil after preliminary treatment) of soil-bound PCBs occurs at 300 degrees C in air. A minimum total PCB destruction efficiency of 95% can be achieved by this process. The effect of changing treatment parameters such as type of mixing, time of mixing and mixing conditions and application of other catalysts like iron oxide and V(2)O(5)/TiO(2) was also investigated. It was found that at 300 degrees C in air, iron oxide and V(2)O(5)/TiO(2) are also good catalysts for remediating PCB contaminated soils. PMID:16962632

  16. Physicochemical and biological quality of soil in hexavalent chromium-contaminated soils as affected by chemical and microbial remediation.

    PubMed

    Liao, Yingping; Min, Xiaobo; Yang, Zhihui; Chai, Liyuan; Zhang, Shujuan; Wang, Yangyang

    2014-01-01

    Chemical and microbial methods are the main remediation technologies for chromium-contaminated soil. These technologies have progressed rapidly in recent years; however, there is still a lack of methods for evaluating the chemical and biological quality of soil after different remediation technologies have been applied. In this paper, microbial remediation with indigenous bacteria and chemical remediation with ferrous sulphate were used for the remediation of soils contaminated with Cr(VI) at two levels (80 and 1,276 mg kg(-1)) through a column leaching experiment. After microbial remediation with indigenous bacteria, the average concentration of water-soluble Cr(VI) in the soils was reduced to less than 5.0 mg kg(-1). Soil quality was evaluated based on 11 soil properties and the fuzzy comprehensive assessment method, including fuzzy mathematics and correlative analysis. The chemical fertility quality index was improved by one grade using microbial remediation with indigenous bacteria, and the biological fertility quality index increased by at least a factor of 6. Chemical remediation with ferrous sulphate, however, resulted in lower levels of available phosphorus, dehydrogenase, catalase and polyphenol oxidase. The result showed that microbial remediation with indigenous bacteria was more effective for remedying Cr(VI)-contaminated soils with high pH value than chemical remediation with ferrous sulphate. In addition, the fuzzy comprehensive evaluation method was proven to be a useful tool for monitoring the quality change in chromium-contaminated soils. PMID:23784058

  17. Remediation of lead and cadmium-contaminated soils.

    PubMed

    Salama, Ahmed K; Osman, Khaled A; Gouda, Neama Abdel-Razeek

    2016-01-01

    The research was designated to study the ability of plants to bio-accumulate, translocate and remove the heavy metals, lead and cadmium from contaminated soil. The herbal plant ryegrass, Lolium multiflorum was investigated as a bio-accumulator plant for these metals. The translocation of these heavy metals in the herbal plant was compared considering root to shoot transport and redistribution of metals in the root and shoot system. The trace metal contents from root and shoot parts were determined using atomic absorption spectrometer. The results showed that the percent of lead and cadmium transferred to ryegrass plant were averaged as 51.39, and 74.57%, respectively, while those remained in the soil were averaged as 48.61 and 25.43% following 60 days of treatment. The soil-plant transfer index in root and shoot system of ryegrass was found to be 0.32 and 0.20 for lead, and 0.50 and 0.25 for cadmium. These findings indicated that the herbal plant ryegrass, Lolium multiflorum is a good accumulator for cadmium than lead. The soil-plant transfer factor (the conc. of heavy metal in plant to the conc. in soil) indicated that the mechanism of soil remedy using the investigated plant is phytoextraction where the amounts of heavy metals transferred by plant roots into the above ground portions were higher than that remained in the soil. The method offers green technology solution for the contamination problem since it is effective technology with minimal impact on the environment and can be easily used for soil remedy. PMID:26515924

  18. Efficiency of modified chemical remediation techniques for soil contaminated by organochlorine pesticides

    NASA Astrophysics Data System (ADS)

    Correa-Torres, S. N.; Kopytko, M.; Avila, S.

    2016-07-01

    This study reports the optimization of innovation chemical techniques in order to improve the remediation of soils contaminated with organochloride pesticides. The techniques used for remediation were dehalogenation and chemical oxidation in soil contaminated by pesticides. These techniques were applied sequentially and combined to evaluate the design optimize the concentration and contact time variables. The soil of this study was collect in cotton crop zone in Agustin Codazzi municipality, Colombia, and its physical properties was measure. The modified dehalogenation technique of EPA was applied on the contaminated soil by adding Sodium Bicarbonate solution at different concentrations and rates during 4, 7 and 14 days, subsequently oxidation technique was implemented by applying a solution of KMnO4 at different concentration and reaction times. Organochlorine were detected by Gas Chromatography analysis coupled Mass Spectrometry and its removals were between 85.4- 90.0% of compounds such as 4, 4’-DDT, 4,4’-DDD, 4,4-DDE, trans-Clordane y Endrin. These results demonstrate that the technique of dehalogenation with oxidation chemistry can be used for remediation soils contaminated by organochloride pesticides.

  19. Investigating biochar as a tool for mine soil remediation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar is a cost-effective, carbon negative soil amendment that can lead to improved soil quality. Research has also demonstrated the efficacy of biochar to sorb heavy metals and agricultural chemicals from contaminated soils, thus effectively reducing the potential for metal and chemical contamin...

  20. Three Soil Quality Demonstrations for Educating Extension Clientele

    ERIC Educational Resources Information Center

    Hoorman, James J.

    2014-01-01

    There is a renewed interest in educating youth, Master Gardeners, and agricultural producers about soil quality. Three soil demonstrations show how soil organic matter increases water holding capacity, improves soil structure, and increases nutrient retention. Exercise one uses clay bricks and sponges to represent mineral soils and soil organic…

  1. Summary performance assessment of in situ remediation technologies demonstrated at Savannah River

    SciTech Connect

    Rosenberg, N.D.; Robinson, B.A.; Birdsell, K.H.; Travis, B.J.

    1994-06-01

    The Office of Technology Development (OTD) in the Department of Energy`s (DOE) Office of Environmental Restoration and Waste Management is investigating new technologies for ``better, faster, cheaper, safer`` environmental remediation. A program at DOE`s Savannah River site was designed to demonstrate innovative technologies for the remediation of volatile organic compounds (VOCs) at nonarid sites. Two remediation technologies, in situ air stripping and in situ bioremediation--both using horizontal wells, were demonstrated at the site between 1990--1993. This brief report summarizes the conclusions from three separate modeling studies on the performance of these technologies.

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

    PubMed

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

    2002-11-01

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

  3. IMPROVED RISK ASSESSMENT AND REMEDIATION OF SOIL METALS BASED ON BIOAVAILABILITY MEASUREMENTS

    EPA Science Inventory

    Heavy metals in soils can comprise risk through plant uptake or soil ingestion. Recent research results and progress in understandings of risks and methods for soil metal remediation will be presented. Beneficial use of composts/bosolids plus limestone to remediate metal killed e...

  4. 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...

  5. Ground water and soil remediation: In situ air stripping using horizontal wells

    SciTech Connect

    Kaback, D.S.; Looney, B.B.; Eddy, C.A.; Hazen, T.C.

    1990-01-01

    An innovative environmental restoration technology, in situ air stripping, has been demonstrated at the US Department of Energy (DOE) Savannah River Site (SRS) in South Carolina. This process, using horizontal wells, is designed to concurrently remediate unsaturated-zone soils and ground water containing Volatile Organic Compounds (VOC). In situ technologies have the potential to substantially reduce costs and time required for remediation as well as improve effectiveness of remediation. Horizontal wells were selected to deliver and extract fluids from the subsurface because their geometry can maximize the efficiency of a remediation system and they have great potential for remediating contaminant sources under existing facilities. The first demonstration of this new technology was conducted for a period of twenty weeks. A vacuum was first drawn on the vadose zone well until a steady-state removal of VOCs was obtained. Air was then injected at three different rates and at two different temperatures. An extensive characterization program was conducted at the site and an extensive monitoring network was installed prior to initiation of the test. Significant quantities of VOCs have been removed from the subsurface (equivalent to an eleven-well, 500-gpm, pump-and-treat system at the same site). Concentrations of VOCs in the ground water have been significantly reduced in a number of the monitoring wells.

  6. Ground water and soil remediation: In situ air stripping using horizontal wells

    SciTech Connect

    Kaback, D.S.; Looney, B.B.; Eddy, C.A.; Hazen, T.C.

    1990-12-31

    An innovative environmental restoration technology, in situ air stripping, has been demonstrated at the US Department of Energy (DOE) Savannah River Site (SRS) in South Carolina. This process, using horizontal wells, is designed to concurrently remediate unsaturated-zone soils and ground water containing Volatile Organic Compounds (VOC). In situ technologies have the potential to substantially reduce costs and time required for remediation as well as improve effectiveness of remediation. Horizontal wells were selected to deliver and extract fluids from the subsurface because their geometry can maximize the efficiency of a remediation system and they have great potential for remediating contaminant sources under existing facilities. The first demonstration of this new technology was conducted for a period of twenty weeks. A vacuum was first drawn on the vadose zone well until a steady-state removal of VOCs was obtained. Air was then injected at three different rates and at two different temperatures. An extensive characterization program was conducted at the site and an extensive monitoring network was installed prior to initiation of the test. Significant quantities of VOCs have been removed from the subsurface (equivalent to an eleven-well, 500-gpm, pump-and-treat system at the same site). Concentrations of VOCs in the ground water have been significantly reduced in a number of the monitoring wells.

  7. Lead immobilization in thermally remediated soils and igneous rocks

    SciTech Connect

    Hickmott, D.D.; Carey, J.W.; Stimac, J.; Larocque, A.; Abell, R.; Gauerke, E.; Eppler, A.

    1997-06-01

    This is the final report for a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The principal goal of this project was to investigate the speciation of lead in the environment at LANL and to determine the feasibility of using thermal remediation methods to immobilize lead in the environment. Lead occurs as pyromorphite [Pb(PO{sub 4}){sub 3}(Cl, OH)], cerussite (PbCO{sub 3}) and galena (PbS) in vapor-phase-altered Bandelier Tuff samples. LANL soils primarily contain cerussite and PbO. Thermal remediation experiments at high temperatures (up to 400 C) suggest that thermal immobilization of highly-reactive Pb compounds in the environment may be feasible, but that this technique is not optimal for more refractory lead phases such as cerussite and PbO.

  8. Immobilization and phytotoxicity of chromium in contaminated soil remediated by CMC-stabilized nZVI.

    PubMed

    Wang, Yu; Fang, Zhanqiang; Kang, Yuan; Tsang, Eric Pokeung

    2014-06-30

    The toxic effect of Cr(VI)-contaminated soil remediated by sodium carboxymethyl cellulose stabilized nanoscale zero-valent iron (CMC-stabilized nZVI) was assessed through in vitro toxicity and phytotoxicity tests. In vitro tests showed that 0.09 g L(-1) of Fe(0) nanoparticles (soil-to-solution ratio was 1 g:5 mL) significantly reduced the toxicity characteristic leaching procedure (TCLP) leachability and physiological based extraction test (PBET) bioaccessibility of Cr by 82% and 58%, respectively. Sequential extraction procedures (SEP) revealed that exchangeable (EX) Cr was completely converted to Fe-Mn oxides (OX) and organic matter (OM). Accordingly, phytotoxicity tests indicated that after 72-h remediation, Cr uptakes by edible rape and Chinese cabbage were suppressed by 61% and 36%, respectively. Moreover, no significant increase in Cr uptake was observed for either species after a 1-month static period for the amended soil. Regarding Fe absorption, germination and seedling growth, both plant species were significantly affected by CMC-nZVI-exposed soils. However, similar phytotoxicity tests conducted after 1 month showed an improvement in cultivation for both plants. Overall, this study demonstrated that CMC-nZVI could significantly enhance Cr immobilization, which reduced its leachability, bioavailability and bioaccumulation by plants. From a detoxification perspective, such remediation is technologically feasible and shows great potential in field applications. PMID:24880637

  9. The Impact of Thermal Remediation on Soil Rehabilitation

    NASA Astrophysics Data System (ADS)

    Pape, Andrew; Switzer, Christine; Knapp, Charles

    2013-04-01

    In an effort to restore the social and economic value of brownfield sites contaminated by hazardous organic liquids, many new remediation techniques involving the use of elevated temperatures to desorb and extract or destroy these contaminants have been developed. These approaches are typically applied to heavily contaminated soils to effect substantial source removal from the subsurface. These processes operate over a range of temperatures from just above ambient to in excess of 1000˚C depending on technology choice and contaminant type. To facilitate the successful rehabilitation of treated soils for agriculture, biomass production, or habitat enrichment the effects of high temperatures on the ability of soil to support biological activity needs to be understood. Four soils were treated with high temperatures or artificially contaminated and subjected to a smouldering treatment (600-1100°C) in this investigation. Subsequent chemical analysis, plant growth trials and microbial analysis were used to characterise the impacts of these processes on soil geochemistry, plant health, and potential for recovery. Decreases were found in levels of carbon (>250˚C), nitrogen (>500˚C) and phosphorus (1000˚C) with intermediate temperatures having variable affects on bio-available levels. Macro and micro nutrients such as potassium, calcium, zinc and copper also showed changes with general trends towards reduced bioavailability at higher temperatures. Above 500°C, cation exchange capacity and phosphate adsorption were lowered indicating that nutrient retention will be a problem in some treated soils. In addition, these temperatures reduced the content of clay sized particles changing the texture of the soils. These changes had a statistically significant impact on plant growth with moderate growth reductions occurring at 250°C and 500°C. Above 750°C, growth was extremely limited and soils treated at these temperatures would need major restorative efforts. Microbial re

  10. In-situ remediation system for groundwater and soils

    DOEpatents

    Corey, J.C.; Kaback, D.S.; Looney, B.B.

    1993-11-23

    A method and system are presented for in-situ remediation of contaminated groundwater and soil where the contaminants, such as toxic metals, are carried in a subsurface plume. The method comprises selection and injection into the soil of a fluid that will cause the contaminants to form stable, non-toxic compounds either directly by combining with the contaminants or indirectly by creating conditions in the soil or changing the conditions of the soil so that the formation of stable, non-toxic compounds between the contaminants and existing substances in the soil are more favorable. In the case of non-toxic metal contaminants, sulfides or sulfates are injected so that metal sulfides or sulfates are formed. Alternatively, an inert gas may be injected to stimulate microorganisms in the soil to produce sulfides which, in turn, react with the metal contaminants. Preferably, two wells are used, one to inject the fluid and one to extract the unused portion of the fluid. The two wells work in combination to create a flow of the fluid across the plume to achieve better, more rapid mixing of the fluid and the contaminants. 4 figures.

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

    PubMed

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

    2015-12-01

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

  12. In-situ remediation system for groundwater and soils

    DOEpatents

    Corey, John C.; Kaback, Dawn S.; Looney, Brian B.

    1993-01-01

    A method and system for in-situ remediation of contaminated groundwater and soil where the contaminants, such as toxic metals, are carried in a subsurface plume. The method comprises selection and injection into the soil of a fluid that will cause the contaminants to form stable, non-toxic compounds either directly by combining with the contaminants or indirectly by creating conditions in the soil or changing the conditions of the soil so that the formation of stable, non-toxic compounds between the contaminants and existing substances in the soil are more favorable. In the case of non-toxic metal contaminants, sulfides or sulfates are injected so that metal sulfides or sulfates are formed. Alternatively, an inert gas may be injected to stimulate microorganisms in the soil to produce sulfides which, in turn, react with the metal contaminants. Preferably, two wells are used, one to inject the fluid and one to extract the unused portion of the fluid. The two wells work in combination to create a flow of the fluid across the plume to achieve better, more rapid mixing of the fluid and the contaminants.

  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. PMID:27337912

  14. SURFACTANT REMEDIATION FIELD DEMONSTRATION USING A VERTICAL CIRCULATION WELL

    EPA Science Inventory

    A field demonstration of surfactant-enhanced solubilization was completed in a shallow unconfined aquifer located at a Coast Guard Station in Traverse City, Michigan. The primary objectives of the study were: (1) to assess the ability of the vertical circulation well (VCW) system...

  15. Remediation of arsenic contaminated soil by coupling oxalate washing with subsequent ZVI/Air treatment.

    PubMed

    Cao, Menghua; Ye, Yuanyao; Chen, Jing; Lu, Xiaohua

    2016-02-01

    The application of a novel coupled process with oxalate washing and subsequent zero-valent iron (ZVI)/Air treatment for remediation of arsenic contaminated soil was investigated in the present study. Oxalate is biodegradable and widely present in the environment. With addition of 0.1 mol L(-1) oxalate under circumneutral condition, 83.7% and 52.6% of arsenic could be removed from a spiked kaolin and an actual contaminated soil respectively. Much more oxalate adsorption on the actual soil was attributed to the higher soil organic matter and clay content. Interestingly, oxalate retained in the washing effluent could act as an organic ligand to promote the oxidation efficiency of ZVI/Air at near neutral pH. Compared with the absence of oxalate, much more As(III) was oxidized. Arsenic was effectively adsorbed on iron (hydr)oxides as the consumption of oxalate and the increase of pH value. For the actual soil washing effluent, about 94.9% of total arsenic was removed after 120 min's treatment without pH adjustment. It has been demonstrated that As(V) was the dominant arsenic speciation adsorbed on iron (hydr)oxides. This study provides a promising alternative for remediation of arsenic contaminated soil in view of its low cost and environmental benign. PMID:26476769

  16. Monitoring of Soil Remediation Process in the Metal Mining Area

    NASA Astrophysics Data System (ADS)

    Kim, Kyoung-Woong; Ko, Myoung-Soo; Han, Hyeop-jo; Lee, Sang-Ho; Na, So-Young

    2016-04-01

    Stabilization using proper additives is an effective soil remediation technique to reduce As mobility in soil. Several researches have reported that Fe-containing materials such as amorphous Fe-oxides, goethite and hematite were effective in As immobilization and therefore acid mine drainage sludge (AMDS) may be potential material for As immobilization. The AMDS is the by-product from electrochemical treatment of acid mine drainage and mainly contains Fe-oxide. The Chungyang area in Korea is located in the vicinity of the huge abandoned Au-Ag Gubong mine which was closed in the 1970s. Large amounts of mine tailings have been remained without proper treatment and the mobilization of mine tailings can be manly occurred during the summer heavy rainfall season. Soil contamination from this mobilization may become an urgent issue because it can cause the contamination of groundwater and crop plants in sequence. In order to reduce the mobilization of the mine tailings, the pilot scale study of in-situ stabilization using AMDS was applied after the batch and column experiments in the lab. For the monitoring of stabilization process, we used to determine the As concentration in crop plants grown on the field site but it is not easily applicable because of time and cost. Therefore, we may need simple monitoring technique to measure the mobility or leachability which can be comparable with As concentration in crop plants. We compared several extraction methods to suggest the representative single extraction method for the monitoring of soil stabilization efficiency. Several selected extraction methods were examined and Mehlich 3 extraction method using the mixture of NH4F, EDTA, NH4NO3, CH3COOH and HNO3 was selected as the best predictor of the leachability or mobility of As in the soil remediation process.

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

    PubMed

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

    2014-12-01

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

  18. Natural remediation of an unremediated soil twelve years after a mine accident: trace element mobility and plant composition.

    PubMed

    Burgos, Pilar; Madejón, Paula; Madejón, Engracia; Girón, Ignacio; Cabrera, Francisco; Murillo, José Manuel

    2013-01-15

    The long-term influence of a mine spill in soil was studied 12 years after the Aznalcóllar accident. Soils where the pyritic sludge was not removed, a fenced plot established for research purposes (2000 m(2)) and soils where the process of remediation was accomplished successfully were sampled and studied in detail. Soils were characterized at different depths, down to 100 cm depth, determining chemical parameters and total concentrations of major and trace elements. Moreover plants colonizing remediated (RE) and non remediated (NRE) soils were also analysed attending their potential risk for herbivores. Strong acidification was observed in the NRE soil except in surface (0-10 cm). The progressive colonization of natural vegetation, more than 90% of the fenced plot covered by plants, could facilitate this increased pH values in the top soil (pH 6). In the NRE soil, the successive oxidation and hydrolysis of sulphide in the deposited sludge on the surface after the accident resulted in a re-dissolution of the most mobile element (Cd, Cu and Zn) and a penetration to deeper layers. Trace element concentrations in plants growing in the NRE soil showed normal contents for higher plants and tolerable for livestock. Nitrogen and mineral nutrients were of the same order in both soils, and also normal for high plants and adequate for animal nutrition. Despite of the natural remediation of the NRE soil, results demonstrate that the remediation tasks carried out in all the area, the Guadiamar Green Corridor at present, were necessary to avoid the leaching of the most mobile elements and minimize the risk of contamination of groundwater sources, many of them close to the Doñana National Park. PMID:23201603

  19. Ecotoxicological impact of two soil remediation treatments in Lactuca sativa seeds.

    PubMed

    Rede, Diana; Santos, Lúcia H M L M; Ramos, Sandra; Oliva-Teles, Filipe; Antão, Cristina; Sousa, Susana R; Delerue-Matos, Cristina

    2016-09-01

    Pharmaceuticals have been identified as environmental emerging pollutants and are present in different compartments, including soils. Chemical remediation showed to be a good and suitable approach for soil remediation, though the knowledge in their impact for terrestrial organisms is still limited. Therefore, in this work, two different chemical remediation treatments (Fenton oxidation and nanoremediation) were applied to a soil contaminated with an environmental representative concentration of ibuprofen (3 ng g(-1)). The phytotoxic impact of a traditional soil remediation treatment (Fenton oxidation) and of a new and more sustainable approach for soil remediation (nanoremediation using green nano-scale zero-valent iron nanoparticles (nZVIs)) was evaluated in Lactuca sativa seeds. Percentage of seed germination, root elongation, shoot length and leaf length were considered as endpoints to assess the possible acute phytotoxicity of the soil remediation treatments as well as of the ibuprofen contaminated soil. Both chemical remediation treatments showed to have a negative impact in the germination and development of lettuce seeds, exhibiting a reduction up to 45% in the percentage of seed germination and a decrease around 80% in root elongation comparatively to the contaminated soil. These results indicate that chemical soil remediation treatments could be more prejudicial for terrestrial organisms than contaminated soils. PMID:27289206

  20. The influence of soil remediation on lead in house dust.

    PubMed

    von Lindern, Ian H; Spalinger, Susan M; Bero, Bridget N; Petrosyan, Varduhi; von Braun, Margrit C

    2003-02-15

    Lead in house dust has long been recognized as a principal source of excess lead absorption among children at the Bunker Hill Superfund Site (BHSS) in northern Idaho. House dust lead concentration from homeowner's vacuum cleaner bags has been monitored since the epidemic of childhood lead poisoning in 1974. Geometric mean house dust lead concentrations decreased from >10000 mg/kg in 1974 to approximately 4000 mg/kg in 1975, in response to air pollution control initiatives at the defective primary lead smelter. After smelter closure, 1983 mean dust lead concentrations were near 3000 mg/kg and were most dependent on soil sources. Following emergency soil removals from public areas and roadsides and fugitive dust control efforts in the mid-1980s, house dust lead decreased by approximately 40-60% to 1200-1500 mg/kg. In 1992, a cleanup goal of 500 mg/kg dust lead community average, with no individual home exceeding 1000 mg/kg, was adopted. This goal was to be achieved by a combination of contaminated soil removals and fugitive dust control efforts throughout the 21 square mile BHSS. Continual reductions in house dust lead concentrations have been noted throughout the residential area soil cleanup. Geometric mean house dust lead concentrations averaged approximately 500-600 mg/kg from 1996 to 1999 and dropped below 500 mg/kg in 2000. Analysis of these data indicates that approximately 20% of the variance in dust lead concentrations is attributed to yard, neighborhood, and community soil lead concentrations. Since 1996, dust lead concentrations and dust and lead loading rates have also been measured by dust mats placed at entryways into the homes. Neighborhood soil lead concentrations, household hygiene, the number of adults living in the home, and the number of hours a child spends outdoors in summer explain approximately 26% of the variance in mat dust lead loading rates. It is estimated that post-remedial house dust lead concentrations will stabilize at 400-500 mg

  1. 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.

  2. Avian Conservation Areas as a Proxy for Contaminated Soil Remediation.

    PubMed

    Lin, Wei-Chih; Lin, Yu-Pin; Anthony, Johnathen; Ding, Tsun-Su

    2015-07-01

    Remediation prioritization frequently falls short of systematically evaluating the underlying ecological value of different sites. This study presents a novel approach to delineating sites that are both contaminated by any of eight heavy metals and have high habitat value to high-priority species. The conservation priority of each planning site herein was based on the projected distributions of eight protected bird species, simulated using 900 outputs of species distribution models (SDMs) and the subsequent application of a systematic conservation tool. The distributions of heavy metal concentrations were generated using a geostatistical joint-simulation approach. The uncertainties in the heavy metal distributions were quantified in terms of variability among 1000 realization sets. Finally, a novel remediation decision-making approach was presented for delineating contaminated sites in need of remediation based on the spatial uncertainties of multiple realizations and the priorities of conservation areas. The results thus obtained demonstrate that up to 42% of areas of high conservation priority are also contaminated by one or more of the heavy metal contaminants of interest. Moreover, as the proportion of the land for proposed remediated increased, the projected area of the pollution-free habitat also increased. Overall uncertainty, in terms of the false positive contamination rate, also increased. These results indicate that the proposed decision-making approach successfully accounted for the intrinsic trade-offs among a high number of pollution-free habitats, low false positive rates and robustness of expected decision outcomes. PMID:26193297

  3. Avian Conservation Areas as a Proxy for Contaminated Soil Remediation

    PubMed Central

    Lin, Wei-Chih; Lin, Yu-Pin; Anthony, Johnathen; Ding, Tsun-Su

    2015-01-01

    Remediation prioritization frequently falls short of systematically evaluating the underlying ecological value of different sites. This study presents a novel approach to delineating sites that are both contaminated by any of eight heavy metals and have high habitat value to high-priority species. The conservation priority of each planning site herein was based on the projected distributions of eight protected bird species, simulated using 900 outputs of species distribution models (SDMs) and the subsequent application of a systematic conservation tool. The distributions of heavy metal concentrations were generated using a geostatistical joint-simulation approach. The uncertainties in the heavy metal distributions were quantified in terms of variability among 1000 realization sets. Finally, a novel remediation decision-making approach was presented for delineating contaminated sites in need of remediation based on the spatial uncertainties of multiple realizations and the priorities of conservation areas. The results thus obtained demonstrate that up to 42% of areas of high conservation priority are also contaminated by one or more of the heavy metal contaminants of interest. Moreover, as the proportion of the land for proposed remediated increased, the projected area of the pollution-free habitat also increased. Overall uncertainty, in terms of the false positive contamination rate, also increased. These results indicate that the proposed decision-making approach successfully accounted for the intrinsic trade-offs among a high number of pollution-free habitats, low false positive rates and robustness of expected decision outcomes. PMID:26193297

  4. Remediation and reclamation of soils heavily contaminated with toxic metals as a substrate for greening with ornamental plants and grasses.

    PubMed

    Jelusic, Masa; Lestan, Domen

    2015-11-01

    Soils highly contaminated with toxic metals are currently treated as waste despite their potential inherent fertility. We applied EDTA washing technology featuring chelant and process water recovery for remediation of soil with 4037, 2527, and 26 mg kg(-1) of Pb, Zn and Cd, respectively in a pilot scale. A high EDTA dose (120 mmol kg(-1) of soil) removed 70%, 15%, and 58% of Pb, Zn, and Cd, respectively, and reduced human oral bioaccessibility of Pb below the limit of quantification and that of Zn and Cd 3.4 and 3.2 times. In a lysimeters experiment, the contaminated and remediated soils were laid into two garden beds (4×1×0.15 m) equipped with lysimeters, and subjected to cultivation of ornamental plants: Impatiens walleriana, Tagetes erecta, Pelargonium×peltatum, and Verbena×hybrida and grasses: Dactylis glomerata, Lolium multiflorum, and Festuca pratensis. Plants grown on remediated soil demonstrated the same or greater biomass yield and reduced the uptake of Pb, Zn and Cd up to 10, 2.5 and 9.5 times, respectively, compared to plants cultivated on the original soil. The results suggest that EDTA remediation produced soil suitable for greening. PMID:25577699

  5. Organics in soils and groundwater at non-arid sites (A-1) integrated demonstration

    SciTech Connect

    Steele, J.L.; Kaback, D.S.; Looney, B.B.

    1994-06-01

    One of the most common environmental problems in the United States is soils and groundwater contaminated with volatile chemical solvents classified as Volatile Organic Compounds (VOCs), which were used as degreasers and cleaning agents. Leakage of solvents (trichloroethylene and tetrachloroethylene) from an underground process sewer line has contaminated soils and underlying groundwaters at SRS. This site was chosen for DOE-OTD`s integrated demonstration program to demonstrate innovative technologies for cleanup of soils and groundwater contaminated with VOCs. The Savannah River Site was especially well suited as the test bed for this integrated demonstration project due to the presence of a pre-existing line source of soil and groundwater-based contamination, on-going environmental remediation efforts at the site, and full cooperation from the concerned environmental regulatory agencies. The Integrated Demonstration (ID) at the Savannah River Site has demonstrated systems of technologies and evaluated them with respect to performance, safety and cost effectiveness.

  6. DEMONSTRATION OF PILOT-SCALE PREVAPORATION SYSTEMS FOR VOLATILE ORGANIC COMPOUND REMOVAL FROM A SURFACTANT ENHANCED AQUIFER REMEDIATION FLUID. I. SPIRAL WOUND MEMBRANE MODULES

    EPA Science Inventory

    During the summer of 1996, a pilot-scale demonstration of a surfactant enhanced aquifer remediation (SEAR) process for removal of dense non-aqueous phase liquids (DNAPLs) from soils was conducted at Hill Air Force Base in Layton, Utah. Five thousand gallons of the extracted DNAP...

  7. 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...

  8. DEMONSTRATION BULLETIN: BIOGENESIS SOIL WASHING TECHNOLOGY - BIOGENESIS

    EPA Science Inventory

    The BioGenesisSM soil washing technology was developed by BioGenesis Enterprises, Inc. to remove organic compounds from soil. The technology uses a proprietary solution (BioGenesisSM cleaner) to transfer organic compounds from the soil matrix to a liquid phase. BioGenesis claims...

  9. Efficient remediation of pentachlorophenol contaminated soil with tetrapolyphosphate washing and subsequent ZVI/Air treatment.

    PubMed

    Cao, Menghua; Wang, Li; Ai, Zhihui; Zhang, Lizhi

    2015-07-15

    In this study, we demonstrate that pentachlorophenol contaminated soil can be efficiently remediated with tetrapolyphosphate washing and subsequent zerovalent iron (ZVI)/Air treatment. 2 mmol L(-1) of tetrapolyphosphate could wash away 52.8% of pentachlorophenol (PCP) at pH 7.0 and 84.2% of pentachlorophenol at pH 11.0 from contaminated soil owing to the promotion effect of tetrapolyphosphate on the soil matrix dispersion and the subsequent solubilization of pentachlorophenol. More importantly, tetrapolyphosphate ions remained in the washing effluent could greatly enhance the molecular oxygen activation by ZVI to oxidize the desorbed PCP without any pH adjustment, and also avoid the competitive consumption of reactive oxygen species, as caused by the common organic surfactants in the washing effluent. Therefore, 85.1% of pentachlorophenol could be aerobically removed from the washing effluent by merely using 5 g L(-1) of ZVI. We also interestingly found that the dissolved iron ions released from the soil could enhance the oxidation of pentachlorophenol in the washing effluent, but the dissolved organic matter had the opposite effect. This study suggests the coupling tetrapolyphosphate washing and subsequent ZVI/Air treatment is an optional approach to remediate pentachlorophenol contaminated soil in view of its low cost and environmental benign. PMID:25781373

  10. Control technologies for remediation of contaminated soil and waste deposits at Superfund lead-battery recycling sites

    SciTech Connect

    Royer, M.D.; Selvakumar, A.; Gaire, R.

    1992-01-01

    The paper primarily addresses remediation of contaminated soils and waste deposits at defunct lead-acid battery recycling sites (LBRS) via immobilization and separation processes. Metallic lead and lead compounds are generally the principal contaminants of concern in soils and waste deposits. Other metals (e.g., cadmium, copper, arsenic, antimony, and selenium) are often present at LBRS. The article is primarily based on experience gained from: (1) Superfund site investigation, removal, and remedial actions, and (2) development and demonstration of control technologies under the Superfund Innovative Technology Evaluation (SITE) Program. The primary remedial options for lead contaminated soils and waste deposits include: (1) no action, (2) off-site disposal, (3) containment, (4) immobilization, (5) separation with resource recovery, and (6) separation without resource recovery.

  11. Review of remediation practices regarding cadmium-enriched farmland soil with particular reference to China.

    PubMed

    Tang, X; Li, Q; Wu, M; Lin, L; Scholz, M

    2016-10-01

    Cadmium-enrichment of farmland soil greatly threatens the sustainable use of soil resources and the safe cultivation of grain. This review paper briefly introduces the status of farmland soil as well as grain, which are both often polluted by cadmium (Cd) in China, and illustrates the major sources of Cd contaminants in farmland soil. In order to meet soil environmental quality standards and farmland environmental quality evaluation standards for edible agricultural products, Cd-enriched farmland soil is frequently remediated with the following prevailing techniques: dig and fill, electro-kinetic remediation, chemical elution, stabilisation and solidification, phytoremediation, field management and combined remediation. Most remediation techniques are still at the stage of small-scale trial experiments in China and few techniques are assessed in field trials. After comparing the technical and economical applicability among different Cd-enriched farmland soil remediation techniques, a novel ecological and hydraulic remediation technique has been proposed, which integrated the advantages of chemical elution, solidification and stabilisation, phytoremediation and field management. The ecological and hydraulic remediation concept is based on existing irrigation and drainage facilities, ecological ditches (ponds) and agronomic measures, which mainly detoxify the Cd-enriched soil during the interim period of crop cultivation, and guarantee the grain safety during its growth period. This technique may shift the challenge from soil to water treatment, and thus greatly enhances the remediation efficiency and shortens the remediation duration. Moreover, the proposed ecological and hydraulic remediation method matches well with the practical choice of cultivation while remediation for Cd-enriched soil in China, which has negligible impacts on the normal crop cultivation process, and thus shows great potential for large area applications. PMID:27562701

  12. Transient behavior of heavy metals in soils during electrokinetic remediation.

    PubMed

    Al-Hamdan, Ashraf Z; Reddy, Krishna R

    2008-03-01

    This paper presents a systematic bench-scale laboratory study performed to assess the transient behavior of chromium, nickel, and cadmium in different soils during electrokinetic remediation. A series of laboratory electrokinetic experiments was conducted using two different clayey soils, kaolin and glacial till. For each type of soil, four electrokinetic experiments with 1, 2, 4, and 10 d of treatment time were performed. In all tests, the contaminants were Cr(VI), Ni(II), and Cd(II) combined in the soil. A geochemical assessment was performed using the geochemical model MINEQL(+) to determine the partitioning of the heavy metals in soils as precipitated, adsorbed, and aqueous forms. Results showed that in kaolin, the extent of Ni(II) and Cd(II) migration towards the cathode increased as the treatment time increased. Unlike kaolin, in glacial till treatment time had no effect on nickel and cadmium migration because of its high buffering capacity. In both kaolin and glacial till, the extent of Cr(VI) migration towards the anode increased as the treatment time increased. However, Cr(VI) migration was higher in glacial till as compared to kaolin because of the high pH conditions that existed in glacial till. In all tests, some Cr(VI) was reduced to Cr(III), and the Cr(VI) reduction rate to Cr(III) as well as the Cr(III) migration were significantly affected by the treatment time. Overall, this study showed that the electroosmotic flow as well as the direction and extent of contaminant migration and removal depend on the polarity of the contaminant, the type of soil, and the treatment duration. PMID:18155269

  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. 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

  15. Coupling bioleaching and electrokinetics to remediate heavy metal contaminated soils.

    PubMed

    Huang, Qingyun; Yu, Zhen; Pang, Ya; Wang, Yueqiang; Cai, Zhihong

    2015-04-01

    In this study, bioleaching was coupled with electrokinetics (BE) to remove heavy metals (Cu, Zn, Cr and Pb) from contaminated soil. For comparison, bioleaching (BL), electrokinetics (EK), and the chemical extraction method were also applied alone to remove the metals. The results showed that the BE method removed more heavy metals from the contaminated soil than the BL method or the EK method alone. The BE method was able to achieve metal solubilization rates of more than 70 % for Cu, Zn and Cr and of more than 40 % for Pb. Within the range of low current densities (<1 mA cm(-2)), higher current density led to more metal removal. However, the metal solubilization rates did not increase with increasing current density when the current density was higher than 1 mA cm(-2). Therefore, it is suggested that bioleaching coupled with electrokinetics can effectively remediate heavy metal-contaminated soils and that preliminary tests should be conducted before field operation to detect the lowest current density for the greatest metal removal. PMID:25680933

  16. Enzymatic technologies for remediation of hydrophobic organic pollutants in soil.

    PubMed

    Eibes, G; Arca-Ramos, A; Feijoo, G; Lema, J M; Moreira, M T

    2015-11-01

    Worldwide there are numerous contaminated sites as a result of the widespread production and use of chemicals in industrial and military activities as well as poor schemes of waste disposal and accidental spillages. The implementation of strategies for decontamination and restoration of polluted sites has become a priority, being bioremediation with biological agents a promising alternative. Enzyme-based technologies offer several advantages over the use of microbial cells, provided that the biocatalyst meets specific requirements: efficiency to remove the target pollutant/s, non-dependency on expensive coenzymes or cofactors, enzyme stability, and an affordable production system. In this mini-review, the direct application of enzymes for in situ soil bioremediation is explored, and also novel ex situ enzymatic technologies are presented. This new perspective provides a valuable insight into the different enzymatic alternatives for decontamination of soils. Examples of recent applications are reported, including pilot-scale treatments and patented technologies, and the principles of operation and the main requirements associated are described. Furthermore, the main challenges regarding the applicability of enzymatic technologies for remediation of hydrophobic organic pollutants from soil are discussed. PMID:26293336

  17. Assessing phytotoxicity of heavy metals in remediated soil.

    PubMed

    Branzini, A; Zubillaga, M S

    2010-01-01

    Copper (Cu), zinc (Zn) and chromium (Cr) are pollutants that usually are accumulated in soils. Their toxicity can be decreased by applying amendments. We proposed to evaluate changes in Cu, Zn, and Cr availability, due to the application of amendments, through chemical analysis and phytotoxicity tests. The phytotoxicity test was carried out using species belonging to Sesbania genus; plant parameters were measured 48, 72, 96, and 168 hours after the start of incubation. The treatments included enriched soil, in addition to biosolid compost and triple superphosphate. Cu and Zn amounts were higher in treatments without amendments, indicating immobilization on the part of these. The amounts of Cr tended to decrease with amendments application. The amendments increased pH values and decreased EC; however, this had no impact on the results. No relationship was found among pH, EC, and plant parameters. Different behaviors were observed. S. virgata showed germination seed delay. In addition, while in S. virgata the IG increased during the assay, in S. punicea it diminished. The application of compost, fertilizer or both combined could be of interest for contaminated soils remediation. The use of chemical analysis and phytotoxicity tests allowed to estimate heavy metal availability and the effect on both Sesbania species. PMID:20734911

  18. Remediation case studies: Ex situ soil treatment technologies (bioremediation, solvent extraction, thermal desorption). Volume 7

    SciTech Connect

    1998-09-01

    The case studies in this volume describe ten applications of ex situ soil treatment technologies, including three applications of land treatment (bioremediation), one application of solvent extraction, and six applications of thermal desorption. Two of the land treatment applications were full-scale remediations of sites contaminated with polycyclic aromatic hydrocarbons (PAHs) and petroleum hydrocarbons, and one was a field demonstration at a site contaminated with pesticides. The solvent extraction application was a full-scale application to treat soil contaminated with PCBs. All six thermal desorption applications were full-scale, and involved treatment of soil contaminated with chlorinated solvents, petroleum hydrocarbons, PAHs, and pesticides. All case studies in this volume are for completed applications.

  19. 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.

  20. Scientific Opportunity to Reduce Risk in Groundwater and Soil Remediation

    SciTech Connect

    Pierce, Eric M.; Freshley, Mark D.; Hubbard, Susan S.; Looney, Brian B.; Zachara, John M.; Liang, Liyuan; Lesmes, D.; Chamberlain, G. M.; Skubal, Karen L.; Adams, V.; Denham, Miles E.; Wellman, Dawn M.

    2009-08-25

    In this report, we start by examining previous efforts at linking science and DOE EM research with cleanup activities. Many of these efforts were initiated by creating science and technology roadmaps. A recurring feature of successfully implementing these roadmaps into EM applied research efforts and successful cleanup is the focus on integration. Such integration takes many forms, ranging from combining information generated by various scientific disciplines, to providing technical expertise to facilitate successful application of novel technology, to bringing the resources and creativity of many to address the common goal of moving EM cleanup forward. Successful projects identify and focus research efforts on addressing the problems and challenges that are causing “failure” in actual cleanup activities. In this way, basic and applied science resources are used strategically to address the particular unknowns that are barriers to cleanup. The brief descriptions of the Office of Science basic (Environmental Remediation Science Program [ERSP]) and EM’s applied (Groundwater and Soil Remediation Program) research programs in subsurface science provide context to the five “crosscutting” themes that have been developed in this strategic planning effort. To address these challenges and opportunities, a tiered systematic approach is proposed that leverages basic science investments with new applied research investments from the DOE Office of Engineering and Technology within the framework of the identified basic science and applied research crosscutting themes. These themes are evident in the initial portfolio of initiatives in the EM groundwater and soil cleanup multi-year program plan. As stated in a companion document for tank waste processing (Bredt et al. 2008), in addition to achieving its mission, DOE EM is experiencing a fundamental shift in philosophy from driving to closure to enabling the long-term needs of DOE and the nation.

  1. Agronomic Practices for Improving Gentle Remediation of Trace Element-Contaminated Soils.

    PubMed

    Kidd, Petra; Mench, Michel; Álvarez-López, Vanessa; Bert, Valérie; Dimitriou, Ioannis; Friesl-Hanl, Wolfgang; Herzig, Rolf; Janssen, Jolien Olga; Kolbas, Aliaksandr; Müller, Ingo; Neu, Silke; Renella, Giancarlo; Ruttens, Ann; Vangronsveld, Jaco; Puschenreiter, Markus

    2015-01-01

    The last few decades have seen the rise of Gentle soil Remediation Options (GRO), which notably include in situ contaminant stabilization ("inactivation") and plant-based (generally termed "phytoremediation") options. For trace element (TE)-contaminated sites, GRO aim to either decrease their labile pool and/or total content in the soil, thereby reducing related pollutant linkages. Much research has been dedicated to the screening and selection of TE-tolerant plant species and genotypes for application in GRO. However, the number of field trials demonstrating successful GRO remains well below the number of studies carried out at a greenhouse level. The move from greenhouse to field conditions requires incorporating agronomical knowledge into the remediation process and the ecological restoration of ecosystem services. This review summarizes agronomic practices against their demonstrated or potential positive effect on GRO performance, including plant selection, soil management practices, crop rotation, short rotation coppice, intercropping/row cropping, planting methods and plant densities, harvest and fertilization management, pest and weed control and irrigation management. Potentially negative effects of GRO, e.g., the introduction of potentially invasive species, are also discussed. Lessons learnt from long-term European field case sites are given for aiding the choice of appropriate management practices and plant species. PMID:25581041

  2. Remediation of Nitrobenzene Contaminated Soil by Combining Surfactant Enhanced Soil Washing and Effluent Oxidation with Persulfate

    PubMed Central

    Yan, Jingchun; Gao, Weiguo; Qian, Linbo; Han, Lu; Chen, Yun; Chen, Mengfang

    2015-01-01

    The combination of surfactant enhanced soil washing and degradation of nitrobenzene (NB) in effluent with persulfate was investigated to remediate NB contaminated soil. Aqueous solution of sodium dodecylbenzenesulfonate (SDBS, 24.0 mmol L-1) was used at a given mass ratio of solution to soil (20:1) to extract NB contaminated soil (47.3 mg kg-1), resulting in NB desorption removal efficient of 76.8%. The washing effluent was treated in Fe2+/persulfate and Fe2+/H2O2 systems successively. The degradation removal of NB was 97.9%, being much higher than that of SDBS (51.6%) with addition of 40.0 mmol L-1 Fe2+ and 40.0 mmol L-1 persulfate after 15 min reaction. The preferential degradation was related to the lone pair electron of generated SO4•−, which preferably removes electrons from aromatic parts of NB over long alkyl chains of SDBS through hydrogen abstraction reactions. No preferential degradation was observed in •OH based oxidation because of its hydrogen abstraction or addition mechanism. The sustained SDBS could be reused for washing the contaminated soil. The combination of the effective surfactant-enhanced washing and the preferential degradation of NB with Fe2+/persulfate provide a useful option to remediate NB contaminated soil. PMID:26266532

  3. Soil remediation using a coupled process: soil washing with surfactant followed by photo-Fenton oxidation.

    PubMed

    Villa, Ricardo D; Trovó, Alam G; Nogueira, Raquel F Pupo

    2010-02-15

    In the present work the use of a coupled process, soil washing and photo-Fenton oxidation, was investigated for remediation of a soil contaminated with p,p'-DDT (DDT) and p,p'-DDE (DDE), and a soil artificially contaminated with diesel. In the soil washing experiments, Triton X-100 (TX-100) aqueous solutions were used at different concentrations to obtain wastewaters with different compositions. Removal efficiencies of 66% (DDT), 80% (DDE) and 100% (diesel) were achieved for three sequential washings using a TX-100 solution strength equivalent to 12 times the effective critical micelle concentration of the surfactant (12 CMC(eff)). The wastewater obtained was then treated using a solar photo-Fenton process. After 6h irradiation, 99, 95 and 100% degradation efficiencies were achieved for DDT, DDE and diesel, respectively. In all experiments, the concentration of dissolved organic carbon decreased by at least 95%, indicating that residual concentration of contaminants and/or TX-100 in the wastewater was very low. The co-extraction of metals was also evaluated. Among the metals analyzed (Pb, Cr, Ni, Cu, Cd, Mn and Co), only Cr and Mn were detected in the wastewater at concentrations above the maximum value permitted by current Brazilian legislation. The effective removal of contaminants from soil by the TX-100 washing process, together with the high degradation efficiency of the solar photo-Fenton process, suggests that this procedure could be a useful option for soil remediation. PMID:19853992

  4. EPA site demonstration of the Biotrol Soil Washing Process

    SciTech Connect

    Stinson, M.K.; Skovronek, H.S.; Ellis, W.D.

    1992-01-01

    A pilot-scale soil washing process, patented by BioTrol, was demonstrated on soil that was contaminated by wood treating waste. The BioTrol Soil Washing was demonstrated in a treatment train sequence with two other pilot-scale units of BioTrol technologies for treatment of waste streams from the soil washer. The three technologies of the treatment train were: The BioTrol Soil Washer (BSW), the BioTrol Aqueous Treatment System (BATS), and the Slurry Bioreactor (SBR). The BioTrol processes were evaluated on pentachlorophenol (PCP) and polynuclear aromatic hydrocarbons (PAHs), which were the primary soil contaminants at the site. The sandy site soil, consisting of less than 10% of fines, was well suited for treatment by soil washing. The BSW successfully separated the feed soil (100% by weight) into 83% of washed soil, 10% of woody residues, and 7% of fines. The soil washer achieved up to 89% removal of PCP and PAHs, based on the difference between their levels in the feed soil and in the washed soil. The BATS degraded up to 94% of PCP in the process water from soil washing. The SBR achieved over 90% removals of PCP and 70-90% removals of PAHs, respectively from the soil washing. Cost of a commercial-scale soil washing, assuming use of all three technologies, was estimated to be $168 per ton of treated soil.

  5. Approaches to the Assessment of the Efficiency of Remediation of Oil-Polluted Soils

    NASA Astrophysics Data System (ADS)

    Anchugova, E. M.; Melekhina, E. N.; Markarova, M. Yu.; Shchemelinina, T. N.

    2016-02-01

    Indices characterizing the enzymatic activity of soils and the contents of aliphatic and polycyclic aromatic hydrocarbons have been applied for estimating the efficiency of remediation of oil-polluted soils in the north of European Russia. Oil-polluted test plots treated with the Universal and Roder biopreparations and subjected to the agrochemical reclamation have been examined. The suggested indices can be used to diagnose and monitor the oil-polluted soils and to assess the efficiency of their remediation.

  6. Use of surfactants for the remediation of contaminated soils: a review.

    PubMed

    Mao, Xuhui; Jiang, Rui; Xiao, Wei; Yu, Jiaguo

    2015-03-21

    Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation. PMID:25528485

  7. Remediation of lead contaminated soil by biochar-supported nano-hydroxyapatite.

    PubMed

    Yang, Zhangmei; Fang, Zhanqiang; Zheng, Liuchun; Cheng, Wen; Tsang, Pokeung Eric; Fang, Jianzhang; Zhao, Dongye

    2016-10-01

    In this study, a high efficiency and low cost biochar-supported nano-hydroxyapatite (nHAP@BC) material was used in the remediation of lead (Pb)-contaminated soil. The remediation effect of nHAP@BC on Pb-contaminated soil was evaluated through batch experiments. The stability, bioaccessibility of Pb in the soil and the change in soil characteristics are discussed. Furthermore, the effects of the amendments on the growth of cabbage mustard seedlings and the accumulation of Pb were studied. The results showed that the immobilization rates of Pb in the soil were 71.9% and 56.8%, respectively, after a 28 day remediation using 8% nHAP and nHAP@BC materials, and the unit immobilization amount of nHAP@BC was 5.6 times that of nHAP, indicating that nHAP@BC can greatly reduce the cost of remediation of Pb in soil. After the nHAP@BC remediation, the residual fraction Pb increased by 61.4%, which greatly reduced the bioaccessibility of Pb in the soil. Moreover, nHAP@BC could effectively reduce the accumulation of Pb in plants by 31.4%. Overall, nHAP@BC can effectively remediate Pb-contaminated soil and accelerate the recovery of soil fertility. PMID:27337496

  8. 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

  9. Electro-osmotic infusion for joule heating soil remediation techniques

    DOEpatents

    Carrigan, Charles R.; Nitao, John J.

    1999-01-01

    Electro-osmotic infusion of ground water or chemically tailored electrolyte is used to enhance, maintain, or recondition electrical conductivity for the joule heating remediation technique. Induced flows can be used to infuse electrolyte with enhanced ionic conductivity into the vicinity of the electrodes, maintain the local saturation of near-electrode regions and resaturate a partially dried out zone with groundwater. Electro-osmotic infusion can also tailor the conductivity throughout the target layer by infusing chemically modified and/or heated electrolyte to improve conductivity contrast of the interior. Periodic polarity reversals will prevent large pH changes at the electrodes. Electro-osmotic infusion can be used to condition the electrical conductivity of the soil, particularly low permeability soil, before and during the heating operation. Electro-osmotic infusion is carried out by locating one or more electrodes adjacent the heating electrodes and applying a dc potential between two or more electrodes. Depending on the polarities of the electrodes, the induced flow will be toward the heating electrodes or away from the heating electrodes. In addition, electrodes carrying a dc potential may be located throughout the target area to tailor the conductivity of the target area.

  10. Effect of EDTA washing of metal polluted garden soils. Part II: Can remediated soil be used as a plant substrate?

    PubMed

    Jelusic, Masa; Vodnik, Dominik; Macek, Irena; Lestan, Domen

    2014-03-15

    In a field experiment on metal contaminated and EDTA-remediated soil we studied plant performance, mycorrhizal associations and prospects of potential re-use of remediated soil as a garden substrate. Two experimental plots of 4 × 1 × 0.3 m were filled, one with remediated and the other with original contaminated soil. Selected cultivars were rotated over the course of 16months. Pb, Zn, Cd and micronutrient plant uptake was measured and their phytoaccessibility was analyzed by the DTPA method. Plant fitness was assessed by chlorophyll fluorescence and gas exchange measurements and evaluation of root colonization were analyzed with mycorrhizal fungi. Remediation reduced Pb and Cd concentrations in roots, green parts and fruits in most of the plants. Phytoaccumulation of Zn was reduced in one half of the cultivars. Some plants suffered from Mn deficiency as total soil Mn was reduced 4-fold and phytoaccessibility of micronutrients Cu, Fe and Mn for 54, 26 and 79%, respectively. Plant biomass was reduced. Photosynthetic parameters of plants grown in original and remediated soil were similar, except for the reduction in Spinacia oleracea. The frequency of mycorrhizal colonization in the roots of Pisum sativum was reduced five-fold and no significant changes were found in Allium cepa roots. Remediation reduced plant uptake of Pb below the concentration stipulated by legislation. Measures to reduce plant accumulation of other toxic metals and to revitalize remediated soil are needed. PMID:24342493

  11. PHYTOTECHNOLOGY RESEARCH: REMEDIATION OF SOIL, SEDIMENT, GROUNDWATER, AND ET CAPS

    EPA Science Inventory

    NRMRL has a number of research efforts underway in the general field of using plants as all or part of an environmental improvement strategy. Planted systems have been demonstrated on several SITE program locations for PAH and PCP degradation in soil, TCE uptake and degradation ...

  12. 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...

  13. Air-Based Remediation Workshop - Section 2 Soil Vapor Extraction

    EPA Science Inventory

    Pursuant to the EPA-AIT Implementing Arrangement 7 for Technical Environmental Collaboration, Activity 11 "Remediation of Contaminated Sties," the USEPA Office of International Affairs Organized a Forced Air Remediation Workshop in Taipei to deliver expert training to the Environ...

  14. EPA SITE DEMONSTRATION OF THE BIOTROL SOIL WASHING PROCESS

    EPA Science Inventory

    A pilot-scale soil washing process, patented by BioTrol, Inc., was demonstrate on soil contaminated by wood treating waste, primarily pentachlorophenol (PCP) and creosote-derived polynuclear aromatic hydrocarbons (PAHs). Although soil washing was the main object of this demonstra...

  15. Phosphorus Amendment Efficacy for In Situ Remediation of Soil Lead Depends on the Bioaccessible Method

    EPA Science Inventory

    A validated method is needed to measure reductions of in vitro bioaccessible (IVBA) Pb in urban soil remediated with amendments. This study evaluated the effect of in vitro extraction solution pH and glycine buffer on bioaccesible Pb in P-treated soils. Two Pb-contaminated soils...

  16. Soil remediation by an advanced oxidative method assisted with ultrasonic energy.

    PubMed

    Flores, Roberto; Blass, Georgina; Domínguez, Vanessa

    2007-02-01

    A new process for the remediation of soil contaminated with hydrocarbons is proposed. The innovation consists on coupling an advanced oxidative method, using a Fenton-type catalyst, with the application of ultrasonic energy. The use of ultrasonic energy not only assists the desorption of the contaminants from the soil, but also promotes the formation of OH radicals, which are the oxidant agents involved in the oxidation process. Different Fenton-like catalysts were employed in the present study; however, the highest removal of toluene and xylenes were obtained with iron sulfate and copper sulfate, respectively. Also, hydrogen peroxide was tested at different concentrations, and it was found that increasing its concentration enhanced the removal of all the contaminants. Finally, it was demonstrated that applying ultrasonic energy to the reacting system process noticeably enhanced the global efficiency of the process due to a synergistic effect in conjunction with the hydrogen peroxide concentration and type of catalyst. PMID:17079076

  17. Experimental and Numerical Investigations of Soil Desiccation for Vadose Zone Remediation: Report for Fiscal Year 2007

    SciTech Connect

    Ward, Andy L.; Oostrom, Mart; Bacon, Diana H.

    2008-02-04

    Apart from source excavation, the options available for the remediation of vadose zone metal and radionuclide contaminants beyond the practical excavation depth (0 to 15 m) are quite limited. Of the available technologies, very few are applicable to the deep vadose zone with the top-ranked candidate being soil desiccation. An expert panel review of the work on infiltration control and supplemental technologies identified a number of knowledge gaps that would need to be overcome before soil desiccation could be deployed. The report documents some of the research conducted in the last year to fill these knowledge gaps. This work included 1) performing intermediate-scale laboratory flow cell experiments to demonstrate the desiccation process, 2) implementing a scalable version of Subsurface Transport Over Multiple Phases–Water-Air-Energy (STOMP-WAE), and 3) performing numerical experiments to identify the factors controlling the performance of a desiccation system.

  18. Determining uranium speciation in contaminated soils by molecular spectroscopic methods: Examples from the Uranium in Soils Integrated Demonstration

    SciTech Connect

    Allen, P.G.; Berg, J.M.; Chisholm-Brause, C.J.; Conradson, S.D.; Donohoe, R.J.; Morris, D.E.; Musgrave, J.A.; Tait, C.D.

    1994-03-01

    The US Department of Energy`s former uranium production facility located at Fernald, OH (18 mi NW of Cincinnati) is the host site for an Integrated Demonstration for remediation of uranium-contaminated soils. A wide variety of source terms for uranium contamination have been identified reflecting the diversity of operations at the facility. Most of the uranium contamination is contained in the top {approximately}1/2 m of soil, but uranium has been found in perched waters indicating substantial migration. In support of the development of remediation technologies and risk assessment, we are conducting uranium speciation studies on untreated and treated soils using molecular spectroscopies. Untreated soils from five discrete sites have been analyzed. We have found that {approximately}80--90% of the uranium exists as hexavalent UO{sub 2}{sup 2+} species even though many source terms consisted of tetravalent uranium species such as UO{sub 2}. Much of the uranium exists as microcrystalline precipitates (secondary minerals). There is also clear evidence for variations in uranium species from the microscopic to the macroscopic scale. However, similarities in speciation at sites having different source terms suggest that soil and groundwater chemistry may be as important as source term in defining the uranium speciation in these soils. Characterization of treated soils has focused on materials from two sites that have undergone leaching using conventional extractants (e.g., carbonate, citrate) or novel chelators such as Tiron. Redox reagents have also been used to facilitate the leaching process. Three different classes of treated soils have been identified based on the speciation of uranium remaining in the soils. In general, the effective treatments decrease the total uranium while increasing the ratio of U(IV) to U(VI) species.

  19. Remediation of Heavy Metal(loid)s Contaminated Soils – To Mobilize or To Immobilize?

    EPA Science Inventory

    Unlike organic contaminants, metal(loid)s do not undergo microbial or chemical degradation and persist for a long time after their introduction. Bioavailability of metal(loid)s plays a vital role in the remediation of contaminated soils. In this review, the remediation of heavy ...

  20. Heavy Metal Phytoremediation: Microbial Indicators of Soil Health for the Assessment of Remediation Efficiency

    NASA Astrophysics Data System (ADS)

    Epelde, Lur; Ma Becerril, José; Alkorta, Itziar; Garbisu, Carlos

    Phytoremediation is an effective, non-intrusive, inexpensive, aesthetically pleasing, socially accepted, promising phytotechnology for the remediation of polluted soils. The objective of any soil remediation process must be not only to remove the contaminant(s) from the soil but, most importantly, to restore the continued capacity of the soil to perform or function according to its potential (i.e., to recover soil health). Hence, indicators of soil health are needed to properly assess the efficiency of a phytoremediation process. Biological indicators of soil health, especially those related to the size, activity and diversity of the soil microbial communities, are becoming increasingly used, due to their sensitivity and capacity to provide information that integrates many environmental factors. In particular, microbial indicators of soil health are valid tools to evaluate the success of metal phytoremediation procedures such as phytoextraction and phytostabilization processes.

  1. Electrical resistance and transport numbers of ion-exchange membranes used in electrodialytic soil remediation

    SciTech Connect

    Hansen, H.K.; Ottosen, L.M.; Villumsen, A.

    1999-08-01

    Electrodialytic soil remediation is a recently developed method to decontaminate heavy metal polluted soil using ion-exchange membranes. In this method one side of the ion-exchange membrane is in direct contact with the polluted soil. It is of great importance to known if this contact with the soil causes damage to the membrane. This work presents the result of transport number and electrical resistance measurements done on four sets of ion-exchange membranes (Ionics, Inc CR67 HMR412 cation-exchange membranes and Ionics, Inc AR204 SXZR anion-exchange membranes), which have been used in four different electrodialytic soil remediation experiments. The experiments showed that after the use in electrodialytic soil remediation, the ion-exchange membranes had transport numbers in the same magnitude as new membranes. The electrical resistance for six membranes did not differ from that of new membranes, whereas two membranes showed a slightly increased resistance.

  2. SF Box--a tool for evaluating the effects on soil functions in remediation projects.

    PubMed

    Volchko, Yevheniya; Norrman, Jenny; Rosén, Lars; Norberg, Tommy

    2014-10-01

    Although remediation is usually aimed at reducing the risks posed by contaminants to human health and the environment, it is also desirable that the remediated soil within future green spaces is capable of providing relevant ecological functions, e.g., basis for primary production. Yet while addressing a contamination problem by reducing contaminant concentration and/or amounts in the soil, the remedial action itself can lead to soil structure disturbances, decline in organic matter and nutrient deficiencies, and in turn affect a soil's capacity to carry out its ecological soil functions. This article presents the Soil Function Box (SF Box) tool that is aimed to facilitate integration of information from suggested soil quality indicators (SQIs) into a management process in remediation using a scoring method. The scored SQIs are integrated into a soil quality index corresponding to 1 of 5 classes. SF Box is applied to 2 cases from Sweden (Kvillebäcken and Hexion), explicitly taking into consideration uncertainties in the results by means of Monte Carlo simulations. At both sites the generated soil quality indices corresponded to a medium soil performance (soil class 3) with a high certainty. The main soil constraints at both Kvillebäcken and Hexion were associated with biological activity in the soil, as soil organisms were unable to supply plant-available N. At the Kvillebäcken site the top layer had a content of coarse fragment (ø > 2 mm) higher than 35%, indicating plant rooting limitations. At the Hexion site, the soil had limited amount of organic matter, thus poor aggregate stability and nutrient cycling potential. In contrast, the soil at Kvillebäcken was rich in organic matter. The soils at both sites were capable of storing a sufficient amount of water for soil organisms between precipitation events. PMID:24903441

  3. Potential Use of Halophytes to Remediate Saline Soils

    PubMed Central

    Hasanuzzaman, Mirza; Nahar, Kamrun; Alam, Md. Mahabub; Bhowmik, Prasanta C.; Hossain, Md. Amzad; Rahman, Motior M.; Prasad, Majeti Narasimha Vara; Ozturk, Munir; Fujita, Masayuki

    2014-01-01

    Salinity is one of the rising problems causing tremendous yield losses in many regions of the world especially in arid and semiarid regions. To maximize crop productivity, these areas should be brought under utilization where there are options for removing salinity or using the salt-tolerant crops. Use of salt-tolerant crops does not remove the salt and hence halophytes that have capacity to accumulate and exclude the salt can be an effective way. Methods for salt removal include agronomic practices or phytoremediation. The first is cost- and labor-intensive and needs some developmental strategies for implication; on the contrary, the phytoremediation by halophyte is more suitable as it can be executed very easily without those problems. Several halophyte species including grasses, shrubs, and trees can remove the salt from different kinds of salt-affected problematic soils through salt excluding, excreting, or accumulating by their morphological, anatomical, physiological adaptation in their organelle level and cellular level. Exploiting halophytes for reducing salinity can be good sources for meeting the basic needs of people in salt-affected areas as well. This review focuses on the special adaptive features of halophytic plants under saline condition and the possible ways to utilize these plants to remediate salinity. PMID:25110683

  4. Potential use of halophytes to remediate saline soils.

    PubMed

    Hasanuzzaman, Mirza; Nahar, Kamrun; Alam, Md Mahabub; Bhowmik, Prasanta C; Hossain, Md Amzad; Rahman, Motior M; Prasad, Majeti Narasimha Vara; Ozturk, Munir; Fujita, Masayuki

    2014-01-01

    Salinity is one of the rising problems causing tremendous yield losses in many regions of the world especially in arid and semiarid regions. To maximize crop productivity, these areas should be brought under utilization where there are options for removing salinity or using the salt-tolerant crops. Use of salt-tolerant crops does not remove the salt and hence halophytes that have capacity to accumulate and exclude the salt can be an effective way. Methods for salt removal include agronomic practices or phytoremediation. The first is cost- and labor-intensive and needs some developmental strategies for implication; on the contrary, the phytoremediation by halophyte is more suitable as it can be executed very easily without those problems. Several halophyte species including grasses, shrubs, and trees can remove the salt from different kinds of salt-affected problematic soils through salt excluding, excreting, or accumulating by their morphological, anatomical, physiological adaptation in their organelle level and cellular level. Exploiting halophytes for reducing salinity can be good sources for meeting the basic needs of people in salt-affected areas as well. This review focuses on the special adaptive features of halophytic plants under saline condition and the possible ways to utilize these plants to remediate salinity. PMID:25110683

  5. Phosphate sources and their suitability for remediation of contaminated soils.

    PubMed

    Knox, A S; Kaplan, D I; Paller, M H

    2006-03-15

    Phosphate minerals and specifically apatite show promise for environmental cleanup because they can form stable compounds with a wide range of cationic contaminants. However, phosphate minerals naturally accumulate some heavy metals that may cause additional contamination of the environment if used improperly. Nine commercially available phosphate materials were evaluated for remediation of contaminated soil based on solubility, concentration of metal/metalloid impurities, and leachability of impurity metal/metalloids. The phosphate materials consisted of three groups: processed (i.e., fertilizers), mined (rock phosphates from different formations), and biogenic (ground fish bone). Processed and mined rock phosphates contained relatively high total concentrations of As, Co, Cr, and Cu but did not exceed the RCRA toxicity characteristic leaching procedure (TCLP) limits. Biogenic apatite contained much lower metal concentrations than processed and mined rock phosphate and was appreciably more soluble. By combining biogenic and mined phosphate it is possible to obtain a wide range of phosphate release rates, permitting rapid immobilization of contaminants while providing a slow release of phosphate for continued long-term treatment. PMID:16150478

  6. Is soil dressing a way once and for all in remediation of arsenic contaminated soils? A case study of arsenic re-accumulation in soils remediated by soil dressing in Hunan Province, China.

    PubMed

    Su, Shiming; Bai, Lingyu; Wei, Caibing; Gao, Xiang; Zhang, Tuo; Wang, Yanan; Li, Lianfang; Wang, Jinjin; Wu, Cuixia; Zeng, Xibai

    2015-07-01

    The investigation of arsenic (As) re-accumulation in an area previously remediated by soil dressing will help in sustainable controlling the risks of As to local ecosystems and should influence management decisions about remediation strategies. In this study, As content in an area remediated by soil dressing and the possible As accumulation risk in agricultural products were investigated. The results indicated that after 7 years of agricultural activities, the average As content (24.6 mg kg(-1)) in surface soil of the investigated area increased by 83.6% compared with that (13.4 mg kg(-1)) in clean soil. Of the surface soil samples (n = 88), 21.6% had As levels that exceeded the limits of the Environmental Quality Standard for Soils of China (GB 15618-1995) and 98.9% of the surface soil samples with As contents exceeding that in clean soil was observed. Soil dressing might be not a remediation method once and for all in some contaminated areas, even though no significant difference in available As content was found between clean (0.18 mg kg(-1)) and surface (0.22 mg kg(-1)) soils. The foreign As in surface soil of the investigated area mainly specifically sorbed with soil colloid or associated with hydrous oxides of Fe and Al, or existed in residual fraction. The upward movement of contaminated soil from the deeper layers and the atmospheric deposition of slag particles might be responsible for the re-accumulation of As in the investigated area. Decreases in soil pH in the investigated soils and the fact that no plant samples had As levels exceeding the limits of the National Food Safety Standards for Contaminants of China (GB 2762-2012) were also observed. PMID:25712882

  7. Electrokinetic soil remediation: Impact of aqueous phase properties on soil surface charge and electroosmotic efficiency

    SciTech Connect

    Vane, L.M.; Zang, G.M.

    1995-10-01

    The electrokinetic remediation of soils is described. The effect of pore fluid properties on the surface charge of clays was examined. Zeta potential results indicate that the electro-osmotic efficiency (flow/voltage ratio) in bentonite should be relatively insensitive to pH and ionic strength variations. The zeta potential of kaolinite, however, was found to be quite sensitive to pH. The electro-osmotic efficiency for kaolinite was found to be equally sensitive to pH. Zeta potential results further indicate that the electro-osmotic efficiency as well as the direction of electroosmosis in kaolinite will be impacted dramatically by the presence of metal cations. These results suggest that zeta potential measurements could be used to study the impact on electro osmotic efficiency of initial site conditions as well as conditions expected during an electrokinetic remediation process.

  8. Effects from different types of construction refuse in the soil on electrodialytic remediation.

    PubMed

    Ottosen, Lisbeth M; Eriksson, Thomas; Hansen, Henrik K; Ribeiro, Alexandra B

    2002-04-26

    At abandoned industrial sites some of the previous buildings are often left behind. If the soil at such site is polluted with heavy metals and is to be remediated by an electrochemical method, the construction refuse within the soil matrix will influence the remediation action. The influence of different sorts of construction refuse on electrodialytic soil remediation was investigated in laboratory cells. An insulator, a stone, resulted in an uneven Cu removal in the close vicinity of the stone itself. An electric conductive screw disturbed the Cu removal due to the redox reactions occurring at the surface of the screw causing pH changes in the soil. Two types of refuse with ionic conducting properties were placed within the test cell, a piece of brick and concrete. The brick did not influence the Cu removal from the soil to a high extent, but it was seen that during the remediation the Cu concentration in the brick itself increased. In the case of concrete the Cu mobilized from the soil was simply found to adsorb very strongly to the concrete and thus the Cu could not be removed from the soil and the concrete as a whole. Furthermore, the removal of Cu in the soil next to the concrete was quite poor. It is very important to be aware of the presence of construction refuse at such sites when planning an electrochemical remediation action. All the refuse types investigated here influenced the Cu removal negatively compared to the reference experiment. PMID:11900914

  9. Microbial fuel cell driving electrokinetic remediation of toxic metal contaminated soils.

    PubMed

    Habibul, Nuzahat; Hu, Yi; Sheng, Guo-Ping

    2016-11-15

    An investigation of the feasibility of in-situ electrokinetic remediation for toxic metal contaminated soil driven by microbial fuel cell (MFC) is presented. Results revealed that the weak electricity generated from MFC could power the electrokinetic remediation effectively. The metal removal efficiency and its influence on soil physiological properties were also investigated. With the electricity generated through the oxidation of organics in soils by microorganisms, the metals in the soils would mitigate from the anode to the cathode. The concentrations of Cd and Pb in the soils increased gradually through the anode to the cathode regions after remediation. After about 143days and 108 days' operation, the removal efficiencies of 31.0% and 44.1% for Cd and Pb at the anode region could be achieved, respectively. Soil properties such as pH and soil conductivity were also significantly redistributed from the anode to the cathode regions. The study shows that the MFC driving electrokinetic remediation technology is cost-effective and environmental friendly, with a promising application in soil remediation. PMID:27388419

  10. 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. PMID:23900948

  11. Electrokinetic-Enhanced Remediation of Phenanthrene-Contaminated Soil Combined with Sphingomonas sp. GY2B and Biosurfactant.

    PubMed

    Lin, Weijia; Guo, Chuling; Zhang, Hui; Liang, Xujun; Wei, Yanfu; Lu, Guining; Dang, Zhi

    2016-04-01

    Electrokinetic-microbial remediation (EMR) has emerged as a promising option for the removal of polycyclic aromatic hydrocarbons (PAHs) from contaminated soils. The aim of this study was to enhance degradation of phenanthrene (Phe)-contaminated soils using EMR combined with biosurfactants. The electrokinetic (EK) remediation, combined with Phe-degrading Sphingomonas sp. GY2B, and biosurfactant obtained by fermentation of Pseudomonas sp. MZ01, degraded Phe in the soil with an efficiency of up to 65.1 % at the anode, 49.9 % at the cathode after 5 days of the treatment. The presence of biosurfactants, electricity, and a neutral electrolyte stimulated the growth of the degrading bacteria as shown by a rapid increase in microbial biomass with time. The electrical conductivity and pH changed little during the course of the treatment, which benefitted the growth of microorganisms and the remediation of Phe-contaminated soil. The EMR system with the addition of biosurfactant had the highest Phe removal, demonstrating the biosurfactant may enhance the bioavailability of Phe and the interaction with the microorganism. This study suggests that the EMR combined with biosurfactants can be used to enhance in situ bioremediation of PAH-contaminated soils. PMID:26683200

  12. Fiscal Year 2010 Program of the U.S. DOE Office of Groundwater and Soil Remediation

    SciTech Connect

    Chamberlain, G. M.; Skubal, Karen L.; Wellman, Dawn M.

    2011-03-07

    The mission of the Office of Groundwater and Soil Remediation (EM-32) is to perform assessments, establish technical criteria and promote cross-site integration. The Office provides guidance for the development and implementation of plans for remediation of groundwater and is responsible for development of technologies needed to reduce risk from groundwater contamination. It is also responsible for providing technical direction and/or assistance to sites in resolving difficult technical groundwater and soil remediation problems. This paper discusses the activities funded by EM-32 for FY-2010.

  13. Enhanced electrokinetic remediation of lead-contaminated soil by complexing agents and approaching anodes.

    PubMed

    Zhang, Tao; Zou, Hua; Ji, Minhui; Li, Xiaolin; Li, Liqiao; Tang, Tang

    2014-02-01

    Optimizing process parameters that affect the remediation time and power consumption can improve the treatment efficiency of the electrokinetic remediation as well as determine the cost of a remediation action. Lab-scale electrokinetic remediation of Pb-contaminated soils was investigated for the effect of complexant ethylenediaminetetraacetic acid (EDTA) and acetic acid and approaching anode on the removal efficiency of Pb. When EDTA was added to the catholyte, EDTA dissolved insoluble Pb in soils to form soluble Pb-EDTA complexes, increasing Pb mobility and accordingly removal efficiency. The removal efficiency was enhanced from 47.8 to 61.5 % when the EDTA concentration was increased from 0.1 to 0.2 M, showing that EDTA played an important role in remediation. And the migration rate of Pb was increased to 72.3 % when both EDTA and acetic acid were used in the catholyte. The "approaching anode electrokinetic remediation" process in the presence of both EDTA and acetic acid had a higher Pb-removal efficiency with an average efficiency of 83.8 %. The efficiency of electrokinetic remediation was closely related to Pb speciation. Exchangeable and carbonate-bounded Pb were likely the forms which could be removed. All results indicate that the approaching anode method in the presence of EDTA and acetic acid is an advisable choice for electrokinetic remediation of Pb-contaminated soil. PMID:24203258

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

    SciTech Connect

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

    1993-09-01

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

  15. The Office of Groundwater & Soil Remediation Fiscal Year 2011 Research & Development Program

    SciTech Connect

    Gerdes, Kurt D.; Chamberlain, Grover S.; Aylward, R. S.; Cercy, Mike; Seitz, Roger; Ramirez, Rosa; Skubal, Karen L.; Marble, Justin; Wellman, Dawn M.; Bunn, Amoret L.; Liang, Liyuan; Pierce, Eric M.

    2011-12-02

    The U.S. Department of Energy’s (DOE) Office of Groundwater and Soil Remediation supports applied research and technology development (AR&TD) for remediation of environments contaminated by legacy nuclear waste. The program centers on delivering advanced scientific approaches and technologies from highly-leveraged, strategic investments that maximize impact to reduce risk and life-cycle cleanup costs. The current groundwater and soil remediation program consists of four applied programmatic areas: • Deep Vadose Zone – Applied Field Research Initiative • Attenuation Based Remedies – Applied Field Research Initiative • Remediation of Mercury and Industrial Contaminants – Applied Field Research Initiative • Advanced Simulation Capability for Environmental Management. This paper provides an overview of the applied programmatic areas, fiscal year 11 accomplishments, and their near-term technical direction.

  16. Changes in soil organic carbon fractions after remediation of a coastal floodplain soil.

    PubMed

    Wong, V N L; McNaughton, C; Pearson, A

    2016-03-01

    Coastal floodplain soils and wetland sediments can store large amounts of soil organic carbon (SOC). These environments are also commonly underlain by sulfidic sediments which can oxidise to form coastal acid sulfate soils (CASS) and contain high concentrations of acidity and trace metals. CASS are found on every continent globally except Antarctica. When sulfidic sediments are oxidised, scalds can form, which are large bare patches without vegetation. However, SOC stocks and fractions have not been quantified in these coastal floodplain environments. We studied the changes in soil geochemistry and SOC stocks and fractions three years after remediation of a CASS scald. Remediation treatments included raising water levels, and addition of either lime (LO) or lime and mulch (LM) relative to a control (C) site. We found SOC concentrations in the remediated sites (LO and LM) were more than double than that found at site C, reflected in the higher SOC stocks to a depth of 1.6 m (426 Mg C/ha, 478 Mg C/ha and 473 Mg C/ha at sites C, LO and LM, respectively). The particulate organic C (POC) fraction was higher at sites LO and LM due to increased vegetation and biomass inputs, compared to site C. Reformation of acid volatile sulfide (AVS) occurred throughout the profile at site LM, whereas only limited AVS reformation occurred at sites LO and C. Higher AVS at site LM may be linked to the additional source of organic matter provided by the mulch. POC can also potentially contribute to decreasing acidity as a labile SOC source for Fe(3+) and SO4(2-) reduction. Therefore, coastal floodplains and wetlands are a large store of SOC and can potentially increase SOC following remediation due to i) reduced decomposition rates with higher water levels and waterlogging, and ii) high C inputs due to rapid revegetation of scalded areas and high rates of biomass production. These results highlight the importance of maintaining vegetation cover in coastal floodplains and wetlands for

  17. Phosphate-Based Mineralization of Arsenic in Contaminated Soil: A Potential Remediation Method for Soil and Groundwater

    NASA Astrophysics Data System (ADS)

    Neupane, G.; Donahoe, R. J.

    2009-12-01

    Soil arsenic contamination resulting from the use of arsenical compounds is a widespread environmental problem. A phosphate-based remediation method which has the potential to immobilize arsenic in both oxidizing and reducing subsurface systems is under laboratory investigation. Although phosphate treatments have been reported to be effective in removal of arsenic from contaminated water, its use in contaminated soils has not been tested. This study aims to (1) determine the competitive adsorption/desorption of arsenate and phosphate at surfaces of ferric hydroxide coated sand in the absence or presence of calcium ions, and (2) develop a method of arsenic fixation which involves phosphoric acid flushing of arsenic from contaminated soil and precipitation of arsenic as apatite-like phases. Ferric hydroxide is a significant arsenic sequestering constituent in soil. Phosphate competes with arsenate for adsorption sites on the ferric hydroxide surface. Batch adsorption experiments conducted using ferric hydroxide coated sand have indicated similar pH-controlled adsorption mechanisms for both arsenate and phosphate. The data obtained from the adsorption experiments is being used to guide the development of a phosphate-based method for soil and groundwater arsenic remediation. Batch experiments were performed using 3g of contaminated soil in contact with 45 ml of treatment fluid (a dilute phosphoric acid and calcium hydroxide solution). Solution samples were collected at 24, 72, 144, 312, and 384 hours, with continuous agitation at 200 rpm. Solution concentrations of phosphorus and calcium generally decreased with time and were primarily controlled by pH. It has been experimentally demonstrated that solution arsenic concentrations can be lowered by maintaining high pH with adequate calcium supply. A batch experiment conducted at pH > 11, using 1 kg of soil in contact with 1 liter of 0.25% H3PO4, precipitated a white material giving an XRD signature indicative of brushite

  18. Implications of Using Thermal Desorption to Remediate Contaminated Agricultural Soil: Physical Characteristics and Hydraulic Processes.

    PubMed

    O'Brien, Peter L; DeSutter, Thomas M; Casey, Francis X M; Derby, Nathan E; Wick, Abbey F

    2016-07-01

    Given the recent increase in crude oil production in regions with predominantly agricultural economies, the determination of methods that remediate oil contamination and allow for the land to return to crop production is increasingly relevant. Ex situ thermal desorption (TD) is a technique used to remediate crude oil pollution that allows for reuse of treated soil, but the properties of that treated soil are unknown. The objectives of this research were to characterize TD-treated soil and to describe implications in using TD to remediate agricultural soil. Native, noncontaminated topsoil and subsoil adjacent to an active remediation site were separately subjected to TD treatment at 350°C. Soil physical characteristics and hydraulic processes associated with agricultural productivity were assessed in the TD-treated samples and compared with untreated samples. Soil organic carbon decreased more than 25% in both the TD-treated topsoil and the subsoil, and total aggregation decreased by 20% in the topsoil but was unaffected in the subsoil. The alteration in these physical characteristics explains a 400% increase in saturated hydraulic conductivity in treated samples as well as a decrease in water retention at both field capacity and permanent wilting point. The changes in soil properties identified in this study suggest that TD-treated soils may still be suitable for sustaining vegetation, although likely at a slightly diminished capacity when directly compared with untreated soils. PMID:27380094

  19. Effects of different remediation treatments on crude oil contaminated saline soil.

    PubMed

    Gao, Yong-Chao; Guo, Shu-Hai; Wang, Jia-Ning; Li, Dan; Wang, Hui; Zeng, De-Hui

    2014-12-01

    Remediation of the petroleum contaminated soil is essential to maintain the sustainable development of soil ecosystem. Bioremediation using microorganisms and plants is a promising method for the degradation of crude oil contaminants. The effects of different remediation treatments, including nitrogen addition, Suaeda salsa planting, and arbuscular mycorrhiza (AM) fungi inoculation individually or combined, on crude oil contaminated saline soil were assessed using a microcosm experiment. The results showed that different remediation treatments significantly affected the physicochemical properties, oil contaminant degradation and bacterial community structure of the oil contaminated saline soil. Nitrogen addition stimulated the degradation of total petroleum hydrocarbon significantly at the initial 30d of remediation. Coupling of different remediation techniques was more effective in degrading crude oil contaminants. Applications of nitrogen, AM fungi and their combination enhanced the phytoremediation efficiency of S. salsa significantly. The main bacterial community composition in the crude oil contaminated saline soil shifted with the remediation processes. γ-Proteobacteria, β-Proteobacteria, and Actinobacteria were the pioneer oil-degraders at the initial stage, and Firmicutes were considered to be able to degrade the recalcitrant components at the later stage. PMID:25240723

  20. Effect of electrokinetic remediation on indigenous microbial activity and community within diesel contaminated soil.

    PubMed

    Kim, Seong-Hye; Han, Hyo-Yeol; Lee, You-Jin; Kim, Chul Woong; Yang, Ji-Won

    2010-07-15

    Electrokinetic remediation has been successfully used to remove organic contaminants and heavy metals within soil. The electrokinetic process changes basic soil properties, but little is known about the impact of this remediation technology on indigenous soil microbial activities. This study reports on the effects of electrokinetic remediation on indigenous microbial activity and community within diesel contaminated soil. The main removal mechanism of diesel was electroosmosis and most of the bacteria were transported by electroosmosis. After 25 days of electrokinetic remediation (0.63 mA cm(-2)), soil pH developed from pH 3.5 near the anode to pH 10.8 near the cathode. The soil pH change by electrokinetics reduced microbial cell number and microbial diversity. Especially the number of culturable bacteria decreased significantly and only Bacillus and strains in Bacillales were found as culturable bacteria. The use of EDTA as an electrolyte seemed to have detrimental effects on the soil microbial activity, particularly in the soil near the cathode. On the other hand, the soil dehydrogenase activity was enhanced close to the anode and the analysis of microbial community structure showed the increase of several microbial populations after electrokinetics. It is thought that the main causes of changes in microbial activities were soil pH and direct electric current. The results described here suggest that the application of electrokinetics can be a promising soil remediation technology if soil parameters, electric current, and electrolyte are suitably controlled based on the understanding of interaction between electrokinetics, contaminants, and indigenous microbial community. PMID:20452646

  1. 75 FR 984 - Draft Recommended Interim Preliminary Remediation Goals for Dioxin in Soil at CERCLA and RCRA Sites

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-07

    ... AGENCY RIN 2050-ZA05 Draft Recommended Interim Preliminary Remediation Goals for Dioxin in Soil at CERCLA...) developed in the Draft Recommended Interim Preliminary Remediation Goals for Dioxin in Soil at Comprehensive... draft recommended interim PRGs for dioxin in soil. These draft recommended interim PRGs were...

  2. Microbial metabolism and community structure in response to bioelectrochemically enhanced remediation of petroleum hydrocarbon-contaminated soil.

    PubMed

    Lu, Lu; Huggins, Tyler; Jin, Song; Zuo, Yi; Ren, Zhiyong Jason

    2014-04-01

    This study demonstrates that electrodes in a bioelectrochemical system (BES) can potentially serve as a nonexhaustible electron acceptor for in situ bioremediation of hydrocarbon contaminated soil. The deployment of BES not only eliminates aeration or supplement of electron acceptors as in contemporary bioremediation but also significantly shortens the remediation period and produces sustainable electricity. More interestingly, the study reveals that microbial metabolism and community structure distinctively respond to the bioelectrochemically enhanced remediation. Tubular BESs with carbon cloth anode (CCA) or biochar anode (BCA) were inserted into raw water saturated soils containing petroleum hydrocarbons for enhancing in situ remediation. Results show that total petroleum hydrocarbon (TPH) removal rate almost doubled in soils close to the anode (63.5-78.7%) than that in the open circuit positive controls (37.6-43.4%) during a period of 64 days. The maximum current density from the BESs ranged from 73 to 86 mA/m(2). Comprehensive microbial and chemical characterizations and statistical analyses show that the residual TPH has a strongly positive correlation with hydrocarbon-degrading microorganisms (HDM) numbers, dehydrogenase activity, and lipase activity and a negative correlation with soil pH, conductivity, and catalase activity. Distinctive microbial communities were identified at the anode, in soil with electrodes, and soil without electrodes. Uncommon electrochemically active bacteria capable of hydrocarbon degradation such as Comamonas testosteroni, Pseudomonas putida, and Ochrobactrum anthropi were selectively enriched on the anode, while hydrocarbon oxidizing bacteria were dominant in soil samples. Results from genus or phylum level characterizations well agree with the data from cluster analysis. Data from this study suggests that a unique constitution of microbial communities may play a key role in BES enhancement of petroleum hydrocarbons

  3. 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

  4. [Effects of Remedies on the Remediation of Typical Pb and Zn-contaminated soil in Huanjiang, Guangxi].

    PubMed

    Zeng, Wei-quan; Song, Bo; Yuan, Li-zhu; Huang, Yu-fei; Fu, Feng-yan

    2015-06-01

    Due to the collapse of the Pb/Zn tailing dam of Huanjiang, Guangxi, the farmland along Huanjiang River are strongly acidic and heavy metal-contaminated, resulting in the loss of agricultural production. To explore some remedies and the migration of heavy metals in heavy metal contaminated-soil of Huanjiang, this study investigated the effects of different types of amendments (lime, calcium magnesium phosphate, organic fertilizer, polypropylene amide) on tested soils through soil leaching test. The results showed that T1 soil was severely acidified, reducing the pH of the soil layer to clean contact, while T2, T3, T4, T5 could significantly improve the contaminated soil pH, ranging from 2.7 to 3.2, 1.6 to 2.7 respectively. Compared with T1, in the contaminated soil at 0-20 cm, T2, T3, T4, T5 could effectively activate Pb and immobilize Zn. Compared with T1, in 20-60 cm clean soil, there was no significant differences in the effect of different treatments on DTPA-Pb and DTPA-Zn (P < 0.05). Compared with T1, T4 and T5 could provide good growing conditions for plants, which might provide technical support for future measurements such as bioremediation. PMID:26387340

  5. Smoldering Remediation of Coal-Tar-Contaminated Soil: Pilot Field Tests of STAR.

    PubMed

    Scholes, Grant C; Gerhard, Jason I; Grant, Gavin P; Major, David W; Vidumsky, John E; Switzer, Christine; Torero, Jose L

    2015-12-15

    Self-sustaining treatment for active remediation (STAR) is an emerging, smoldering-based technology for nonaqueous-phase liquid (NAPL) remediation. This work presents the first in situ field evaluation of STAR. Pilot field tests were performed at 3.0 m (shallow test) and 7.9 m (deep test) below ground surface within distinct lithological units contaminated with coal tar at a former industrial facility. Self-sustained smoldering (i.e., after the in-well ignition heater was terminated) was demonstrated below the water table for the first time. The outward propagation of a NAPL smoldering front was mapped, and the NAPL destruction rate was quantified in real time. A total of 3700 kg of coal tar over 12 days in the shallow test and 860 kg over 11 days in the deep test was destroyed; less than 2% of total mass removed was volatilized. Self-sustaining propagation was relatively uniform radially outward in the deep test, achieving a radius of influence of 3.7 m; strong permeability contrasts and installed barriers influenced the front propagation geometry in the shallow test. Reductions in soil hydrocarbon concentrations of 99.3% and 97.3% were achieved in the shallow and deep tests, respectively. Overall, this provides the first field evaluation of STAR and demonstrates that it is effective in situ and under a variety of conditions and provides the information necessary for designing the full-scale site treatment. PMID:26523324

  6. SITE DEMONSTRATION OF THE TORONTO HARBOUR COMMISSIONERS SOIL RECYCLING PROJECT

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA), in cooperation with the Toronto Harbour Commissioners (THC), conducted a Superfund InnovativeTechnology Evaluation (SITE) demonstration of the THC Soil Recycle Treatment Train. The treatment train consists of three technologies op...

  7. 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...

  8. Effects of gentle remediation technologies on soil biological and biochemical activities - a review.

    NASA Astrophysics Data System (ADS)

    Marschner, B.; Haag, R.; Renella, G.

    2009-04-01

    Remediation technologies for contaminated sites are generally designed to reduce risks for human health, groundwater or plant quality. While some drastic remediation measures such as soil excavation, thermal treatment or soil washing eliminate or strongly reduce soil life, in-situ treatments involving plants or immobilizing additives may also restore soil functionality by establishing or promoting a well structured and active community of soil organisms. Biological parameters that are sensitive to contaminants and other pedo-environmental conditions and which contribute to biogeochemical nutrient cycles, can be used as synthetic indicators of the progress and also the efficiency of given remediation approaches. Data from long-term studies on re-vegetated mine spoils show that biological and biochemical activity is enhanced with increasing plant density and diversity. Among the soil amendments, most measures that introduce organic matter or alkalinity to the contaminated soils also improve microbial or faunal parameters. Only few amendments, such as phosphates and chelators have deleterious effects on soil biota. In this review, soil microbial biomass and the activity of the enzymes phosphatase and arylsulphatase are identified as suitable and sensitive biological indicators for soil health. The results and future research needs are are summarized.

  9. 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

  10. Minimizing soil remediation volume through specification of excavation and materials handling procedures

    SciTech Connect

    Oresik, W.L.S.; Otten, M.T.; Nelson, M.D.

    1994-12-31

    The technologies currently available for treating soils contaminated with the explosives 2,4,6-trinitroluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazene (RDX) are both limited and expensive. Therefore, an important consideration in soils remediation is the preparation of construction specifications and contract drawings which limit the volume of soil that will be required to undergo treatment. Construction specifications and contract drawings were developed for the Contaminated Soil Remediation of the Explosives Washout Lagoons at Umatilla Depot Activity (UMDA) with the following primary objectives: (1) limit the volume of soil excavated from the Explosives Washout Lagoons and Explosives Washout Plant Areas, (2) minimize materials handling, and (3) reduce the excavated volume of soil which will undergo treatment.

  11. Demonstration testing and evaluation of in situ soil heating. Treatability study work plan, Revision 1

    SciTech Connect

    Sresty, G.C.

    1994-07-07

    A Treatability Study planned for the demonstration of the in situ electromagnetic (EM) heating process to remove organic solvents is described in this Work Plan. The treatability study will be conducted by heating subsurface vadose-zone soils in an organic plume adjacent to the Classified Burial Ground K-1070-D located at K-25 Site, Oak Ridge. The test is scheduled to start during the fourth quarter of FY94 and will be completed during the first quarter of FY95. The EM heating process for soil decontamination is based on volumetric heating technologies developed during the `70s for the recovery of fuels from shale and tar sands by IIT Research Institute (IITRI) under a co-operative program with the US Department of Energy (DOE). Additional modifications of the technology developed during the mid `80s are currently used for the production of heavy oil and waste treatment. Over the last nine years, a number of Government agencies (EPA, Army, AF, and DOE) and industries sponsored further development and testing of the in situ heating and soil decontamination process for the remediation of soils containing hazardous organic contaminants. In this process the soil is heated in situ using electrical energy. The contaminants are removed from the soil due to enhanced vaporization, steam distillation and stripping. IITRI will demonstrate the EM Process for in situ soil decontamination at K-25 Site under the proposed treatability study. Most of the contaminants of concern are volatile organics which can be removed by heating the soil to a temperature range of 85 to 95 C. The efficiency of the treatment will be determined by comparing the concentration of contaminants in soil samples. Samples will be obtained before and after the demonstration for a measurement of the concentration of contaminants of concern.

  12. Anionic-nonionic mixed-surfactant-enhanced remediation of PAH-contaminated soil.

    PubMed

    Shi, Zhentian; Chen, Jiajun; Liu, Jianfei; Wang, Ning; Sun, Zheng; Wang, Xingwei

    2015-08-01

    Soil washing is an efficient remediation technique that enhances the solubility of polycyclic aromatic hydrocarbons (PAHs) in specific surfactant to remediate PAH-contaminated soil. This study evaluated the remediation efficiency of PAH-contaminated soil from a coke oven plant by comparing sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), and Triton X-100 (TX100), as well as TX100-SDS and TX100-SDBS mixed surfactants. Results showed that SDS-TX100 and SDBS-TX100 had synergistic effects on PAH solubilization when surfactant concentrations were above their critical micelle concentration. Competitive effects of the three solubilized PAHs (phenanthrene with three rings, fluoranthene with four rings, and benzo[a]pyrene with five rings) with a particular anionic-nonionic mixed surfactant were investigated. PAHs with more rings were found to slightly decrease the solubility in surfactant solution of PAHs with fewer rings, whereas PAHs with fewer rings promoted the solubility in surfactant solution of PAHs with more rings. The removal ratios of PAHs during the remediation of actual PAH-contaminated soil were best improved by the anionic-nonionic mixed surfactant TX100-SDS (9:1), followed by TX100-SDS (8:2), TX100-SDS (7:3), TX100-SDBS (7:3), TX100, SDBS, and SDS. Therefore, anionic-nonionic mixed surfactants can help improve the remediation performance of PAHs based on their application in tests of cleaning actual PAH-contaminated soil from a coke oven plant. PMID:26002358

  13. [Effect of different soil types on the remediation of copper-pyrene compound contaminated soils by EK-oxidation process].

    PubMed

    Fan, Guang-Ping; Cang, Long; Zhou, Dong-Mei; Zhou, Li-Xiang

    2011-11-01

    The effect of different soil types (red soil,yellow-brown soil and black soil) on the electrokinetic (EK)-oxidation remediation of heavy metals-organic pollutant contaminated soil was studied in laboratory-scale experiments. Copper and pyrene were chosen as model pollutant, and 12% H2O2, 10% hydroxypropyl-beta-cyclodextrin and 0.01 mol x L(-1) NaNO3 solution were added into the anode and cathode cell. The applied voltage was 1 V x cm(-1). After 15 days of EK remediation, the removal rate of pyrene and copper in red soil, yellow-brown soil and black soil were 38.5%, 46.8%, 51.3% for pyrene and 85.0%, 22.6%, 24.1% for Cu, respectively. The high pH of black soil produced high electroosmotic flow and increased the exposure of oxidants and pollutants, meanwhile the low clay content was also conducive to the desorption of pyrene. The low pH and organic matter of red soil affected the chemical species distribution of Cu and increased its removal rate. It is concluded that soil pH, clay content and heavy metal speciation in soil are the dominant factors affecting the migration and removal efficiency of pollutants. PMID:22295647

  14. Assessment of salt tolerant plants to remediate saline soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil salinity has intensified in the James River valley in east central South Dakota in the past 20 years. Surface evaporation on poorly drained and subirrigated soils leaves salts on the soil surface. Replacing evaporation from the soil surface with transpiration through deep-rooted salt-tolerant...

  15. Microbial fuel cells demonstrate high coulombic efficiency applicable for water remediation.

    PubMed

    Devasahayam, Mercy; Masih, Sam A

    2012-06-01

    Microbial fuel cells (MFCs) convert biomass into electricity by the metabolic activity of microorganisms and are also used for remediation and water treatment. Power output was compared for a dual chambered membrane MFC using either E. coli or two Yamuna river samples, Yamuna (before the Sangam region)--slow flow (sample 1) and Sangam region--fast flow (sample 2). E. coli and the two river water samples 1 and 2 gave a maximum voltage of 779, 463 and 415 mV respectively. Using E. coli the maximum power density obtained with a 100 omega resistor was 220.66 mW/cm2 and the highest power generated 6068.41 mW. The results demonstrate E. coli, river sample 1 and river sample 2 have a comparable coulombic efficiency of 85.2, 71 and 77% respectively when using 0.4% sucrose as substrate. The decrease in chemical oxidative demand of all river water samples using MFC technology demonstrates efficient remediation of inland water. PMID:22734255

  16. Design, installation and operational methods of implementing horizontal wells for in situ groundwater and soil remediation

    SciTech Connect

    Larson, R.B.

    1996-12-31

    The design and installation of horizontal wells is the primary factor in the efficiency of the remedial actions. Often, inadequacies in the design and installation of remediation systems are not identified until remedial actions have commenced, at which time, required modifications of operational methods can be costly. The parameters required for designing a horizontal well remediation system include spatial variations in contaminant concentrations and lithology, achievable injection and/or extraction rates, area of influence from injection and/or extraction processes, and limitations of installation methods. As with vertical wells, there are several different methods for the installation of horizontal wells. This paper will summarize four installation methods for horizontal wells, including four sites where horizontal wells have been utilized for in-situ groundwater and soil remediation.

  17. 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

  18. Synergistic effects of bioremediation and electrokinetics in the remediation of petroleum-contaminated soil.

    PubMed

    Guo, Shuhai; Fan, Ruijuan; Li, Tingting; Hartog, Niels; Li, Fengmei; Yang, Xuelian

    2014-08-01

    The present study evaluated the coupling interactions between bioremediation (BIO) and electrokinetics (EK) in the remediation of total petroleum hydrocarbons (TPH) by using bio-electrokinetics (BIO-EK) with a rotatory 2-D electric field. The results demonstrated an obvious positive correlation between the degradation extents of TPH and electric intensity both in the EK and BIO-EK tests. The use of BIO-EK showed a significant improvement in degradation of TPH as compared to BIO or EK alone. The actual degradation curve in BIO-EK tests fitted well with the simulated curve obtained by combining the degradation curves in BIO- and EK-only tests during the first 60 d, indicating a superimposed effect of biological degradation and electrochemical stimulation. The synergistic effect was particularly expressed during the later phase of the experiment, concurrent with changes in the microbial community structure. The community composition changed mainly according to the duration of the electric field, leading to a reduction in diversity. No significant spatial shifts in microbial community composition and bacterial numbers were detected among different sampling positions. Soil pH was uniform during the experimental process, soil temperature showed no variations between the soil chambers with and without an electric field. PMID:24613072

  19. Effect of Remediation Parameters on in-Air Ambient Dose Equivalent Rates When Remediating Open Sites with Radiocesium-contaminated Soil.

    PubMed

    Malins, Alex; Kurikami, Hiroshi; Kitamura, Akihiro; Machida, Masahiko

    2016-10-01

    Calculations are reported for ambient dose equivalent rates [H˙*(10)] at 1 m height above the ground surface before and after remediating radiocesium-contaminated soil at wide and open sites. The results establish how the change in H˙*(10) upon remediation depends on the initial depth distribution of radiocesium within the ground, on the size of the remediated area, and on the mass per unit area of remediated soil. The remediation strategies considered were topsoil removal (with and without recovering with a clean soil layer), interchanging a topsoil layer with a subsoil layer, and in situ mixing of the topsoil. The results show the ratio of the radiocesium components of H˙*(10) post-remediation relative to their initial values (residual dose factors). It is possible to use the residual dose factors to gauge absolute changes in H˙*(10) upon remediation. The dependency of the residual dose factors on the number of years elapsed after fallout deposition is analyzed when remediation parameters remain fixed and radiocesium undergoes typical downward migration within the soil column. PMID:27575348

  20. Leaching of Contamination from Stabilization/Solidification Remediated Soils of Different Texture

    NASA Astrophysics Data System (ADS)

    Burlakovs, Juris; Kasparinskis, Raimonds; Klavins, Maris

    2012-09-01

    Development of soil and groundwater remediation technologies is a matter of great importance to eliminate historically and currently contaminated sites. Stabilization/solidification (S/S) refers to binding of waste contaminants to a more chemically stable form and thus diminishing leaching of contamination. It can be performed using cement with or without additives in order to stabilize and solidify soil with the contamination in matrix. A series of experiments were done to determine leaching properties of spiked soils of different texture bound with cement. Results of experiments showed, that soil texture (content of sand, silt and clay particles) affects the leaching of heavy metals from stabilized soils.

  1. Technology needs for remediation: Hanford and other DOE sites. Buried Waste Integrated Demonstration Program

    SciTech Connect

    Stapp, D.C.

    1993-01-01

    Technologies are being developed under the Buried Waste Integrated Demonstration (BWID) program to facilitate remediation of the US Department of Energy`s (DOE) buried and stored low-level radioactive, transuranic (TRU), and mixed radioactive and hazardous buried wastes. The BWID program is being coordinated by the Idaho National Engineering Laboratory (INEL) in southeastern Idaho, a DOE site that has large volumes of buried radioactive wastes. The program is currently focusing its efforts on the problems at INEL`s Subsurface Disposal Area (SDA) of the Radioactive Waste Management Complex (RWMC). As specific technologies are successfully demonstrated, they will be available for transfer to applications at other DOE buried waste sites. The purpose of this study is to present buried waste technology needs that have been identified for DOE sites other than INEL.

  2. Laboratory and field evaluation of the gas treatment approach for insitu remediation of chromate-contaminated soils

    SciTech Connect

    Thornton, E.C.; Jackson, R.L.

    1994-04-01

    Laboratory scale soil treatment tests have been conducted as part of an effort to develop and implement an in situ chemical treatment approach to the remediation of chromate-contaminated soils through the use of reactive gases. These tests involved three different soil samples that were contaminated with Cr(VI) at the 200 ppM level. Treatment of the contaminated soils was performed by passing 100 ppM and 2000 ppM concentrations of hydrogen sulfide in nitrogen through soil columns until a S:Cr mole ratio of 10:1 was achieved. The treated soils were then leached with groundwater or deionized water and analyzed to assess the extent of chromium immobilization. Test results indicate >90% immobilization of chromium and demonstrate that the treatment process is irreversible. Ongoing developmental efforts are being directed towards the demonstration and evaluation of the gas treatment approach in a field test at a chromate-contaminated site. Major planned activities associated with this demonstration include laboratory testing of waste site soil samples, design of the treatment system and injection/extraction well network, geotechnical and geochemical characterization of the test site, and identification and resolution of regulatory and safety requirements.

  3. Operable Unit 3-13, Group 3, Other Surface Soils (Phase I) Remedial Action Report

    SciTech Connect

    L. Davison

    2007-07-31

    This Remedial Action Report summarizes activities undertaken to remediate the Operable Unit 3-13, Group 3, Other Surface Soils, Phase I sites at the Idaho Nuclear Technology and Engineering Center at the Idaho National Laboratory Site. The 10 sites addressed in this report were defined in the Operable Unit 3-13 Record of Decision and subsequent implementing documents. This report concludes that remediation requirements and cleanup goals established for these 10 sites have been accomplished and are hereafter considered No Action or No Further Action sites.

  4. An assessment of the effectiveness and impact of electrokinetic remediation for pyrene-contaminated soil.

    PubMed

    Xu, Sujuan; Guo, Shuhai; Wu, Bo; Li, Fengmei; Li, Tingting

    2014-11-01

    The effectiveness of electrokinetic remediation for pyrene-contaminated soil was investigated by an anode-cathode separated system using a salt bridge. The applied constant voltage was 24 V and the electrode gap was 24 cm. Two types of soil (sandy soil and loam soil) were selected because of their different conductive capabilities. The initial concentrations of pyrene in these soil samples were 261.3mg/kg sandy soil and 259.8 mg/kg loam soil. After treatment of the sandy soil and loam soil for seven days, 56.8% and 20.1% of the pyrene had been removed respectively. Under the same power supply voltage, the removal of the pollutant from the sandy soil was greater than that from the loam soil, due to the higher current and lower pH. Further analysis revealed that the effectiveness of electrokinetic remediation was affected by the energy expenditure, and was associated with changes in soil properties. PMID:25458684

  5. [Research on the Screening Method of Soil Remediation Technology at Contaminated Sites and Its Application].

    PubMed

    Bai, Li-ping; Luo, Yun; Liu, Li; Zhou, You-ya; Yan, Zeng-guang; Li, Fa-sheng

    2015-11-01

    Soil remediation technology screening is an important procedure in the supervision of contaminated sites. The efficiency and costs of contaminated site remediation will be directly affected by the applicability of soil remediation technology. The influencing factors include characteristics of contaminants, site conditions, remediation time and costs should be considered to determine the most applicable remediation technology. The remediation technology screening was commonly evaluated by the experienced expert in China, which limited the promotion and application of the decision making method. Based on the supervision requirements of contaminated sites and the research status at home and abroad, the screening method includes preliminary screening and explicit evaluation was suggested in this paper. The screening index system was constructed, and the extension theory was used to divide the technology grade. The extension theory could solve the problem of human interference in the evaluation process and index value assignment. A chromium residue contaminated site in China was selected as the study area, and the applicable remediation technologies were suggested by the screening method. The research results could provide a scientific and technological support for the supervision and management of contaminated sites in China. PMID:26911012

  6. Field demonstration of remedial technologies at a former manufactured gas plant site

    SciTech Connect

    Moreau, J.P.

    1998-12-31

    From the mid 1800s until the late 1950s, the major energy source for domestic lighting, heating, and cooking was a manufactured fuel derived from the pyrolysis of coal and oil. These manufactured gas production facilities were located throughout the country; at one time more than 3000 plants may have been in operation, with 180 in New York state alone. During the 1950s, the installation of a vast interstate gas pipeline system allowed the transport of relatively inexpensive natural gas from oil production fields to the metropolitan areas. This natural gas had a BTU content of almost twice that of manufactured gas and, being inherently cheaper, resulted in the overnight demise of the MGP industry. The vast majority of the MGP facilities were demolished and the sites either converted to other uses or abandoned. In the early 1980s, utilities discovered these long abandoned production facilities during various environmental site assessments and audits. In 1990, NMPC initiated a project at a MGP byproduct disposal site (EPRI Site 24) to investigate the technologies necessary for removal of contaminated source materials and soils, treatment of the impacted soil, and evaluation of the potential for natural attenuation of a contaminated groundwater plume (EPRI, 1996). MGP-impacted soil from this site was transported to two treatment facilities: a cement Kiln in North Carolina, and an asphalt plant in Virginia. This experience generated considerable data on management of these sites, even though this site was a simple disposal area and not a former production facility. A long-term monitoring program is indicating that natural attenuation processes appear to b responsible for the decreasing levels of key constituents in the groundwater after source materials are removed. A number of key lessons learned were generated from the study, especially recognizing that transportation is a major cost component in site remediation.

  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. PMID:24875876

  8. Impact of carbonate on the efficiency of heavy metal removal from kaolinite soil by the electrokinetic soil remediation method.

    PubMed

    Ouhadi, V R; Yong, R N; Shariatmadari, N; Saeidijam, S; Goodarzi, A R; Safari-Zanjani, M

    2010-01-15

    While the feasibility of using electrokinetics to decontaminate soils has been studied by several authors, the effects of soil composition on the efficiency of this method of decontamination has yet to be fully studied. This study focuses its attention on the effect of "calcite or carbonate" (CaCO(3)) on removal efficiency in electrokinetic soil remediation. Bench scale experiments were conducted on two soils: kaolinite and natural-soil of a landfill in Hamedan, Iran. Prescribed quantities of carbonates were mixed with these soils which were subsequently contaminated with zinc nitrate. After that, electrokinetic experiments were conducted to determine the efficiency of electrokinetic remediation. The results showed that an increase in the quantity of carbonate caused a noticeable increase on the contaminant retention of soil and on the resistance of soil to the contaminant removal by electrokinetic method. Because the presence of carbonates in the soil increases its buffering capacity, acidification is reduced, resulting in a decrease in the rate of heavy metal removed from the contaminant soil. This conclusion was validated by the evaluation of efficiency of electrokinetic method on a soil sample from the liner of a waste disposal site, with 28% carbonates. PMID:19733966

  9. Remediation of hexavalent chromium contaminated soil by biochar-supported zero-valent iron nanoparticles.

    PubMed

    Su, Huijie; Fang, Zhanqiang; Tsang, Pokeung Eric; Zheng, Liuchun; Cheng, Wen; Fang, Jianzhang; Zhao, Dongye

    2016-11-15

    In this study, a kind of high-efficiency and low-cost biochar-supported zero-valent iron nanoparticles (nZVI@BC) was synthesised and used in the remediation of Cr(VI)-contaminated soil. The remediation tests indicated that the immobilisation efficiency of Cr(VI) and Crtotal was 100% and 91.94%, respectively, by 8g nZVI@BC per kg soil for 15 d of remediation. Further investigations showed that exchangeable Cr was almost completely converted to Fe-Mn oxides and organic matter. Moreover, nZVI@BC could effectively improve soil fertility and reduce the leachability of Fe caused by nZVI. At the same time, the cabbage mustard growth experiments indicated that the phytotoxicity of Cr(VI) and Fe in the seedlings was effectively decreased by nZVI@BC treatment, and that the cabbage mustard growth was enhanced. PMID:27469041

  10. Use of phytoremediation and biochar to remediate heavy metal polluted soils: a review

    NASA Astrophysics Data System (ADS)

    Paz-Ferreiro, J.; Lu, H.; Fu, S.; Méndez, A.; Gascó, G.

    2014-02-01

    Anthropogenic activities are resulting in an increase of the use and extraction of heavy metals. Heavy metals cannot be degraded and hence accumulate in the environment, having the potential to contaminate the food chain. This pollution threatens soil quality, plant survival and human health. The remediation of heavy metals deserves attention, but it is impaired by the cost of these processes. Phytoremediation and biochar are two sound environmental technologies which could be at the forefront to mitigate soil pollution. This review provides an overview of the state of the art of the scientific research on phytoremediation and biochar application to remediate heavy-metal-contaminated soils. Research to date has attempted only in a limited number of occasions to combine both techniques, however we discuss the potential advantages of combining both, and the potential mechanisms involved in the interaction between phytoremediators and biochar. We identified specific research needs to ensure a sustainable use of phytoremediation and biochar as remediation tools.

  11. Remediation of PAH-contaminated soil at a gas manufacturing plant by a combined two-phase partition system washing and microbial degradation process.

    PubMed

    Gong, Xuan; Xu, Xinyang; Gong, Zongqiang; Li, Xiaojun; Jia, Chunyun; Guo, Meixia; Li, Haibo

    2015-08-01

    The aim of this study was to design a remediation technique using both soil washing and microbial degradation to remove polycyclic aromatic hydrocarbons (PAHs) from contaminated soil. PAH biodegradation by inoculation of Mycobacterium sp. was first tested. The effectiveness of washing agents (Tween 80 solution, biodiesel, and a two-phase partition system (TPPS)) was then evaluated with column experiments. Third, the combination of TPPS washing and microbial degradation was studied. PAH bioavailability before and after biodegradation and the joint remediation was also assessed using hydroxypropyl-β-cyclodextrin (HPCD) extraction. Only phenanthrene and anthracene were noticeably biodegradable when the soil was inoculated with Mycobacterium sp. TPPS containing 2% (v/v) biodiesel and 2.5% (w/v) Tween 80 was used as the washing agent for the joint remediation test because it gave higher PAH extractions than Tween 80 solution with lower doses, and there was less residue in the soil. Joint TPPS washing and microbial degradation gave a total PAH removal of 92.6%, which was much higher than the results from either the biodegradation or washing experiments alone. Removals of all high molecular weight (HMW) PAHs were improved. Bioavailable concentrations of all PAHs decreased significantly after the joint remediation process, indicating that there were reduced risks from all PAHs. The results demonstrate that the combination of TPPS washing and microbial degradation is a useful and innovative process for remediation of PAH-contaminated soils. PMID:25874432

  12. 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. PMID:25628112

  13. Tourmaline combined with Phanerochaete chrysosporium to remediate agricultural soil contaminated with PAHs and OCPs.

    PubMed

    Wang, Cuiping; Yu, Li; Zhang, Zhiyuan; Wang, Baolin; Sun, Hongwen

    2014-01-15

    The potential application on tourmaline was explored. The combination of tourmaline and Phanerochaete chrysosporium was conducted to remediate the field soil from the Dagu Drainage River bank of Tianjin in China. The total PAH and OCP concentrations in the soil were 6.4±0.05 and 145.9±1.9mg/kg, respectively. During the 60 day remediation program, the remediation degradation rates of all the 16 U.S. EPA priority PAHs and OCPs were 53.2±4.7% and 43.5±3.1%, respectively. The PAH and OCP removal rates were 31.9±2.9% and 26.4±1.8%, respectively, in soil with the addition of tourmaline, and the removal rates were 40.5±2.3% and 34.2±3.9%, respectively, in soil with the addition of P. chrysosporium. Thus, the combination of tourmaline and P. chrysosporium promoted the bioremediation rate of PAHs and OCPs in the soil, compared with the rates obtained using tourmaline or P. chrysosporium individually for the remediation of PAH and OCP degradation. In addition, tourmaline can promote the generation of soil hydrogen peroxidase and invertase enzyme, significantly increase the indigenous bacterial community and the number of PAH and OCP-degraders compared to those in the control, and reduce the soil humic acid content. Hence, the present study provides a potential alternative for the remediation of soils contaminated by PAHs and OCPs. PMID:24333677

  14. Acoustically enhanced remediation of contaminated soils and ground water. Volume 1

    SciTech Connect

    1995-10-01

    The Phase 1 laboratory bench-scale investigation results have shown that acoustically enhanced remediation (AER) technology can significantly accelerate the ground water remediation of non-aqueous phase liquids (NAPLs) in unconsolidated soils. The testing also determined some of the acoustic parameters which maximize fluid and contaminant extraction rates. A technology merit and trade analysis identified the conditions under which AER could be successfully deployed in the field, and an analysis of existing acoustical sources and varying methods for their deployment found that AER technology can be successfully deployed in-situ. Current estimates of deployability indicate that a NAPL plume 150 ft in diameter can be readily remediated. This program focused on unconsolidated soils because of the large number of remediation sites located in this type of hydrogeologic setting throughout the nation. It also focused on NAPLs and low permeability soil because of the inherent difficult in the remediation of NAPLs and the significant time and cost impact caused by contaminated low permeability soils. This overall program is recommended for Phase 2 which will address the technology scaling requirements for a field scale test.

  15. Simultaneous removal of organic contaminants and heavy metals from kaolin using an upward electrokinetic soil remediation process.

    PubMed

    Wang, Jing-Yuan; Huang, Xiang-Jun; Kao, Jimmy C M; Stabnikova, Olena

    2007-06-01

    Kaolins contaminated with heavy metals, Cu and Pb, and organic compounds, p-xylene and phenanthrene, were treated with an upward electrokinetic soil remediation (UESR) process. The effects of current density, cathode chamber flushing fluid, treatment duration, reactor size, and the type of contaminants under the vertical non-uniform electric field of UESR on the simultaneous removal of the heavy metals and organic contaminants were studied. The removal efficiencies of p-xylene and phenanthrene were higher in the experiments with cells of smaller diameter or larger height, and with distilled water flow in the cathode chamber. The removal efficiency of Cu and Pb were higher in the experiments with smaller diameter or shorter height cells and 0.01M HNO(3) solution as cathode chamber flow. In spite of different conditions for removal of heavy metals and organics, it is possible to use the upward electrokinetic soil remediation process for their simultaneous removal. Thus, in the experiments with duration of 6 days removal efficiencies of phenanthrene, p-xylene, Cu and Pb were 67%, 93%, 62% and 35%, respectively. The experiment demonstrated the feasibility of simultaneous removal of organic contaminants and heavy metals from kaolin using the upward electrokinetic soil remediation process. PMID:17110023

  16. Effects of remediation train sequence on decontamination of heavy metal-contaminated soil containing mercury.

    PubMed

    Hseu, Zeng-Yei; Huang, Yu-Tuan; Hsi, Hsing-Cheng

    2014-09-01

    When a contaminated site contains pollutants including both nonvolatile metals and Hg, one single remediation technology may not satisfactorily remove all contaminants. Therefore, in this study, chemical extraction and thermal treatment were combined as a remediation train to remove heavy metals, including Hg, from contaminated soil. A 0.2 M solution of ethylenediamine tetraacetic acid (EDTA) was shown to be the most effective reagent for extraction of considerable amounts of Cu, Pb, and Zn (> 50%). Hg removal was ineffective using 0.2 M EDTA, but thermogravimetric analysis suggested that heating to 550 degrees C with a heating rate of 5 degrees C/min for a duration of 1 hr appeared to be an effective approach for Hg removal. With the employment of thermal treatment, up to 99% of Hg could be removed. However executing thermal treatment prior to chemical extraction reduced the effectiveness of the subsequent EDTA extraction because nonvolatile heavy metals were immobilized in soil aggregates after the 550 degrees C treatment. The remediation train of chemical extraction followed by thermal treatment appears to remediate soils that have been contaminated by many nonvolatile heavy metals and Hg. Implications: A remediation train conjoining two or more techniques has been initialized to remove multiple metals. Better understandings of the impacts of treatment sequences, namely, which technique should be employed first on the soil properties and the decontamination efficiency, are in high demand. This study provides a strategy to remove multiple heavy metals including Hg from a contaminated soil. The interactions between thermal treatment and chemical extraction on repartitioning of heavy metals was revealed. The obtained results could offer an integrating strategy to remediate the soil contaminated with both heavy metals and volatile contaminants. PMID:25282998

  17. Remediation of saline-sodic soil with flue gas desulfurization gypsum in a reclaimed tidal flat of southeast China.

    PubMed

    Mao, Yumei; Li, Xiaping; Dick, Warren A; Chen, Liming

    2016-07-01

    Salinization and sodicity are obstacles for vegetation reconstruction of coastal tidal flat soils. A study was conducted with flue gas desulfurization (FGD)-gypsum applied at rates of 0, 15, 30, 45 and 60Mg/ha to remediate tidal flat soils of the Yangtze River estuary. Exchangeable sodium percentage (ESP), exchangeable sodium (ExNa), pH, soluble salt concentration, and composition of soluble salts were measured in 10cm increments from the surface to 30cm depth after 6 and 18months. The results indicated that the effect of FGD-gypsum is greatest in the 0-10cm mixing soil layer and 60Mg/ha was the optimal rate that can reduce the ESP to below 6% and decrease soil pH to neutral (7.0). The improvement effect was reached after 6months, and remained after 18months. The composition of soluble salts was transformed from sodic salt ions mainly containing Na(+), HCO3(-)+CO3(2-) and Cl(-) to neutral salt ions mainly containing Ca(2+) and SO4(2-). Non-halophyte plants were survived at 90%. The study demonstrates that the use of FGD-gypsum for remediating tidal flat soils is promising. PMID:27372137

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

    EPA Science Inventory

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

  19. 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.

  20. REMEDIAL COSTS FOR MTBE IN SOIL AND GROUND WATER

    EPA Science Inventory

    The extensive contamination of methyl tertiary butyl ether (MTBE) in ground water has introduced concerns about the increased cost of remediation of MTBE releases compared to sites with BTEX only contamination. In an attempt to evaluate these costs, cost information for 311 sit...

  1. REMEDIAL COSTS FOR MTBE IN SOIL AND GROUND WATER

    EPA Science Inventory

    Widespread contamination of methyl tert-butyl ether (MTBE) in ground water has raised concerns about the increased cost of remediation of MTBE releases compared to BTEX-only sites. To evaluate these costs, cost information for 311 sites was furnished by U.S. EPA Office of Underg...

  2. REMEDIAL COSTS FOR MTBE IN SOIL AND GROUND WATER

    EPA Science Inventory

    The extensive contamination of methyl tertiary butyl ether (MTBE) in ground water has introduced concerns about the increased cost of remediation of MTBE releases compared to sites with BTEX only contamination. In an attempt to evaluate these costs, cost information for 311 site...

  3. Remediation of hydrocarbon-contaminated soils by ex situ microwave treatment: technical, energy and economic considerations.

    PubMed

    Falciglia, P P; Vagliasindi, F G A

    2014-01-01

    In this study, the remediation of diesel-polluted soils was investigated by simulating an ex situ microwave (MW) heating treatment under different conditions, including soil moisture, operating power and heating duration. Based on experimental data, a technical, energy and economic assessment for the optimization of full-scale remediation activities was carried out. Main results show that the operating power applied significantly influences the contaminant removal kinetics and the moisture content in soil has a major effect on the final temperature reachable during MW heating. The first-order kinetic model showed an excellent correlation (r2 > 0.976) with the experimental data for residual concentration at all operating powers and for all soil moistures tested. Excellent contaminant removal values up to 94.8% were observed for wet soils at power higher than 600 W for heating duration longer than 30 min. The use of MW heating with respect to a conventional ex situ thermal desorption treatment could significantly decrease the energy consumption needed for the removal of hydrocarbon contaminants from soils. Therefore, the MW treatment could represent a suitable cost-effective alternative to the conventional thermal treatment for the remediation of hydrocarbon-polluted soil. PMID:25145181

  4. Study of Soil Washing for Remediation of Pb and Zn Contaminated Coastal Landfill

    NASA Astrophysics Data System (ADS)

    Park, S.; Kim, S.; Lee, M.

    2013-12-01

    As a result of analyzing the pre-treatment process of Pb, Zn in contaminated coastal landfill soil presented by Korean Soil Analysis Method, the each concentration was presented 577.00mg/kg, 3894.34mg/kg. This soil was critically contaminated with Pb and Zn because it was exceeded the Standard of soil contamination(2area: Pb-400mg/kg, Zn-600mg/kg). Soil remediation efficiency of the soil washing process for the removal of Pb and Zn was determined to be consistent with the results. The batch experiment on the several washing solutions(HCl, HNO3), washing solutions concentrations(0.1-0.8M) and the ratio of soil vs. solution for soil washing(1:3, 1:5 and 1:10) was performed. The results of experiments, washing time was appropriate in 30 minutes. The removal efficiency of soil washing increased as the ratio of soil vs. washing solution increased. But, in the case of heavy metals, the soil vs. solution for soil washing was determined as the optimal ratio of 1 : 5. Five consecutive soil washing with 0.5M of HCl and HNO3 solutions were performed. Results of experiments, in case of Pb was removed by target removal efficiency from soil on the twice washing. With in case of Zn was over on the first washing by target removal efficiency, but suggesting that twice consecutive soil washing is desirable as stability at field. Results of consecutive soil washing experiments, the removal efficiency maintained lower than 10 % after the 4th washing. From the results, demanding consecutive washing is not recommended. Results about the heavy metal contaminated soil washing experiments of the coastal landfill, in the case of HCl with more than 0.5 M of solution was performed at 1:5 of soil ratio vs. solution, 30 minutes of washing time and 2-3 consecutive soil washing. And in the case of HNO3 with 0.8 M of solution was performed various ratios of soil vs. washing solution, suggesting that 2-3 consecutive soil washing was reached to Pb and Zn target removal efficiency. Key words

  5. SRS Data Report for Lynntech Soil Ozone Treatment Demonstration Adjacent to the 321-M Solvent Storage Tank Pad

    SciTech Connect

    Vangelas, K.M.

    2000-08-29

    At large industrial sites like the A/M Area of the Savannah River Site (SRS), undissolved dense non-aqueous phase liquid (DNAPL) in soil and groundwater is the most significant barrier to successful clean up. DNAPL acts as a reservoir that will continue to generate contaminant levels far above remediation concentration goals well into the future. In an effort to achieve remediation goals and reduce future costs, the SRS DNAPL program is evaluating technologies that will recycle or destroy DNAPL. In situ oxidation is one class of DNAPL destruction technologies. A demonstration of this class of technologies was conducted at SRS in the winter of 1999 and spring of 2000 employing ozone as the oxidant. Lynntech Inc. through a Small Business Innovative Research grant partnered with the Savannah River Site to demonstrate their soil ozone treatment technology. The Savannah River Site provided the demonstration location and field support of the test. This demonstration involved treating a small vadose zone DNAPL plume in the A/M Area over a 29 day period. Approximately 2000 pounds of DNAPL (perchloroethylene [PCE] and trichloroethylene [TCE]) were removed through the soil vapor extraction unit (SVEU). Soil core data indicate that approximately 300 pounds of DNAPL were removed from the test site. This report documents the data collected by SRS personnel during the demonstration of Lynntech's Soil Ozone Treatment Technology.

  6. The use of microbial gene abundance in the development of fuel remediation guidelines in polar soils.

    PubMed

    Richardson, Elizabeth L; King, Catherine K; Powell, Shane M

    2015-04-01

    Terrestrial fuel spills in Antarctica commonly occur on ice-free land around research stations as the result of human activities. Successful spill clean-ups require appropriate targets that confirm contaminated sites are no longer likely to pose environmental risk following remediation. These targets are based on knowledge of the impacts of contaminants on the soil ecosystem and on the response of native biota to contamination. Our work examined the response of soil microbial communities to fuel contamination by measuring the abundance of genes involved in critical soil processes, and assessed the use of this approach as an indicator of soil health in the presence of weathered and fresh fuels. Uncontaminated and contaminated soils were collected from the site of remediation treatment of an aged diesel spill at Casey Station, East Antarctica in December 2012. Uncontaminated soil was spiked with fresh Special Antarctic Blend (SAB) diesel to determine the response of the genes to fresh fuel. Partly remediated soil containing weathered SAB diesel was diluted with uncontaminated soil to simulate a range of concentrations of weathered fuel and used to determine the response of the genes to aged fuel. Quantitative PCR (qPCR) was used to measure the abundance of rpoB, alkB, cat23, and nosZ in soils containing SAB diesel. Differences were observed between the abundance of genes in control soils versus soils containing weathered and fresh fuels. Typical dose-response curves were generated for genes in response to the presence of fresh fuel. In contrast, the response of these genes to the range of weathered fuel appeared to be due to dilution, rather than to the effect of the fuel on the microbial community. Changes in microbial genes in response to fresh contamination have potential as a sensitive measure of soil health and for assessments of the effect of fuel spills in polar soils. This will contribute to the development of remediation guidelines to assist in management

  7. 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.

  8. Modern approaches to remediation of heavy metal polluted soils: A review

    NASA Astrophysics Data System (ADS)

    Koptsik, G. N.

    2014-07-01

    The main principles and approaches to remediation of in situ polluted soils aimed at the removal or control of heavy metals (washing, stabilization, phytoremediation, and natural restoration) are analyzed. The prospects of gentle methods of stabilization oriented at the reduction of the mobility and biological availability of heavy metals due to the processes of adsorption, ionic exchange, and precipitation are emphasized. The use of sorbents and the traditional application of liming and phosphates to fix metal pollutants in soils is considered. The necessary conditions for successful soil remediation are the assessment of its economic efficiency, the analysis of the ecological risks, and confirming the achievement of the planned purposes related to the content of available metals in the soils.

  9. Low-concentration tailing and subsequent quicklime-enhanced remediation of volatile chlorinated hydrocarbon-contaminated soils by mechanical soil aeration.

    PubMed

    Ma, Yan; Du, Xiaoming; Shi, Yi; Xu, Zhu; Fang, Jidun; Li, Zheng; Li, Fasheng

    2015-02-01

    Mechanical soil aeration has long been regarded as an effective ex-situ remediation technique and as suitable for remediation of large-scale sites contaminated by volatile organic compounds (VOCs) at low cost. However, it has been reported that the removal efficiency of VOCs from soil is relatively low in the late stages of remediation, in association with tailing. Tailing may extend the remediation time required; moreover, it typically results in the presence of contaminants residues at levels far exceeding regulations. In this context, the present study aimed to discuss the tailing that occurs during the process of remediation of soils contaminated artificially with volatile chlorinated hydrocarbons (VCHs) and to assess possible quicklime-enhanced removal mechanisms. The results revealed the following conclusions. First, temperature and aeration rate can be important controls on both the timing of appearance of tailing and the levels of residual contaminants. Furthermore, the addition of quicklime to soil during tailing can reduce the residual concentrations rapidly to below the remedial target values required for site remediation. Finally, mechanical soil aeration can be enhanced using quicklime, which can improve the volatilization of VCHs via increasing soil temperature, reducing soil moisture, and enhancing soil permeability. Our findings give a basic understanding to the elimination of the tailing in the application of mechanical soil aeration, particularly for VOCs-contaminated soils. PMID:25433980

  10. Evaluation of the assimilation of As by vegetables in contaminated soils submitted to a remediation process

    NASA Astrophysics Data System (ADS)

    Pérez-Sirvent, Carmen; Martinez Sanchez, Maria Jose; Agudo, Ines; Belen Martinez, Lucia; Bech, Jaume

    2016-04-01

    A greenhouse trial was carried out to evaluate the assimilation of heavy metals by three types of plants (lettuce, onion and broccoli), different parts of which are destined for human and farm animals consumption (leaves, roots, fruits). The experiments were carried out to check the validity of the use of calcareous materials to recover soils contaminated with heavy metals. The aim of this work was to apply a technology for decontamination to ensure that As do not enter into the trophic chain at risky levels and analyze and to assess the risk pre and post operational of the different treatments proposed. The materials used was a soils to be remediated (mining soils) and the materials used for remediation were lime filler and Construction and Demolition Waste (CDW). The plants were cultivated in greenhouse with several types of soil. Five experiments were used, namely, Tc (contaminated soil), T1 (uncontaminated soil (blank soil)), T2 (50% T1 + 50% Tc), T3 (Tc + (25%) lime residues coming from quarries) and T4 (Tc + (25%) residues coming from demolition and construction activities). The entire project involves twenty experiments which were prepared from soils highly contaminated mixed with two types of calcareous materials. The total As content of the soils samples, rhizosphere and vegetable samples, were measured and the translocation factor (TF), which is defined as the ratio of metal concentration in the leaves or shoots to the roots, and the Bioconcentration factor (BCF), which is defined as the ratio of metal concentration in the roots to that in soil were calculated. The use of CDR is shown to be a suitable way for remediating soils contaminated by metals. The methodology permits a revalorization of CDW.

  11. Enhancing electrokinetic remediation of cadmium- contaminated soils with stepwise moving anode method.

    PubMed

    Chen, Xue J; Shen, Zhe M; Yuan, Tao; Zheng, Shen S; Ju, Bing X; Wang, Wen H

    2006-01-01

    This paper proposed an innovative approach by stepwise moving anode towards cathode to enhance the cadmium (Cd) removal from soil during the process of electrokinetic (EK) remediation. Fixed anode tests and moving anode tests were carried out for 60 hours to compare their performances. The anode-cathode spacing was 21 cm. Constant voltage grade of 1.0 V cm(-1) was applied in this study. The parameters included pH, electrical conductivity, current, Cd concentration and speciation distributions, energy consumptions, etc. It was found that the pH values in the moving anode tests were relatively lower than those of the fixed tests. In the moving anode test, the removal efficiency of Cd in the soils at the fraction of S4 was enhanced by 54.9% compared with that of the fixed anode tests. After 60 hours of treatment, approximately 80% of the spiked soils (100.63 mg x kg(-1) of Cd) in the system were successfully remedied in the moving anode tests; and the mean removal efficiency was 73% for actual field-contaminated soil (54.26 mg x kg(-1) of Cd). It is effective to remedy actual contaminated soils. In addition, the cumulative energy consumptions were 59.29 kWhm(-3) and 31.52 kWhm(-3) for the fixed and moving tests, respectively. The results revealed that the Cd removal efficiency was improved by the moving anode method. Moreover, less energy was consumed in the moving test. The proposed approach does not need to introduce extra chemicals nor adjust the pH in the system to enhance the Cd removal by EK remediation. The basic idea proposed in this paper provides a novel and environmental friendly method to enhance the EK remediation of heavy metals contaminated soils. PMID:17000543

  12. Preliminary results from the investigation of thermal effects in electrokinetics soil remediation

    SciTech Connect

    Krause, T.R.; Tarman, B.

    1993-10-01

    Electrokinetics is an emerging soil remediation technology. Contaminants are extracted from the soil as a result of a complex set of phenomena that occur when an electric gradient is imposed across a soil-water system. The primary phenomena include electroosmosis, electromigration, and electrophoresis. Secondary phenomena, such as changes in solubility or speciation of various chemical components, may occur as a result of electrically induced changes in the chemical environment of the system. Numerous factors, such as temperature, may affect each of these phenomena and, consequently, the overall process efficiency. We have begun an investigation of thermal effects in the extraction of potassium dichromate from kaolinite soils under conditions of constant saturation and dewatering. Preliminary results suggest that increasing the soil temperature from 21 to 55{degrees}C may decrease the processing time under saturated conditions. However, increasing the soil temperature under dewatering, conditions causes soil cracking, which reduces the overall process efficiency.

  13. Respiration testing for bioventing and biosparging remediation of petroleum contaminated soil and ground water

    SciTech Connect

    Gray, A.L.; Brown, A.; Moore, B.J.; Payne, R.E.

    1996-12-01

    Respiration tests were performed to measure the effect of subsurface aeration on the biodegradation rates of petroleum hydrocarbon contamination in vadose zone soils (bioventing) and ground water (biosparging). The aerobic biodegradation of petroleum contamination is typically limited by the absence of oxygen in the soil and ground water. Therefore, the goal of these bioremediation technologies is to increase the oxygen concentration in the subsurface and thereby enhance the natural aerobic biodegradation of the organic contamination. One case study for biosparging bioremediation testing is presented. At this site atmospheric air was injected into the ground water to increase the dissolved oxygen concentration in the ground water surrounding a well, and to aerate the smear zone above the ground water table. Aeration flow rates of 3 to 8 cfm (0.09 to 0.23 m{sup 3}/min) were sufficient to increase the dissolved oxygen concentration. Petroleum hydrocarbon biodegradation rates of 32 to 47 {micro}g/l/hour were calculated based on measurements of dissolved oxygen concentration in ground water. The results of this test have demonstrated that biosparging enhances the biodegradation of petroleum hydrocarbons, but the results as they apply to remediation are not known. Two case studies for bioventing respiration testing are presented.

  14. Response of winter birds to soil remediation along the Columbia River at the Hanford Site

    SciTech Connect

    Becker, James M.; McKinstry, Craig A.

    2004-04-01

    The Columbia River at the Hanford Site, located in south-central Washington State, USA, is a regionally important refugium for overwintering birds. Some of the river shoreline has been designated by the U.S. Department of Energy for environmental clean-up following past production of materials for nuclear weapons. We evaluated the effects of soil remediation on winter birds at six inactive nuclear reactor areas. Remediation activities consisted of daily excavation and removal of approximately 1,035 t of contaminated soil from previously herbicided and denuded areas located between 30 m and 400 m and mostly in line-of-sight of the river shoreline. Remediation activities had no apparent effect on numbers of riverine or terrestrial birds using adjacent undisturbed shoreline and riparian habitat.

  15. Response of winter birds to soil remediation along the Columbia River at the Hanford Site.

    PubMed

    Becker, J M; McKinstry, C A

    2004-01-01

    The Columbia River at the Hanford Site, located in south-central Washington State, U.S.A., is a regionally important refugium for overwintering birds. Some of the river shoreline has been designated by the U.S. Department of Energy for environmental clean-up following past production of materials for nuclear weapons. We evaluated the effects of soil remediation on winter birds at six inactive nuclear reactor areas. Remediation activities consisted of daily excavation and removal of approximately 1035 t of contaminated soil from previously herbicided and denuded areas located between 30 and 400 m and mostly in line-of-sight of the river shoreline. Remediation activities had no apparent effect on numbers of riverine or terrestrial birds using adjacent undisturbed shoreline and riparian habitat. PMID:15074620

  16. Six-phase soil heating for enhanced removal of contaminants: Volatile organic compounds in non-arid soils integrated demonstration, Savannah River Site

    SciTech Connect

    Gauglitz, P.A.; Bergsman, T.M.; Caley, S.M.

    1994-10-01

    In November 1993, Pacific Northwest Laboratory (PNL) and Savannah River Site (SRS) personnel conducted a demonstration of six-phase soil heating (SPSH) at the Savannah River Site (SRS) in Aiken, South Carolina. The demonstration was part of the Volatile Organic Compounds in Non-Arid Soils Integrated Demonstration being conducted near the M-Area operations at the SRS, along a corridor that once contained a process sewer leading to the M-Area seepage basin. In the early 1980s, this sewer line was discovered to be leaking process wastes into the subsurface and contributing to groundwater contamination in the vicinity of M-Area seepage basin. Although use of the sewer line has been discontinued, the slow release of chlorinated solvents such as trichloroethylene (TCE) and perchloroethylene (PCE) from the heterogeneous vadose zone soil continues to be a source of potential groundwater contamination. A significant portion of the VOCs at the demonstration site are retained in low-permeability clay zones. Previous studies have shown that the rate of conventional SVE remediation of the SRS clays is quite slow. The permeability of the clay is of order 10{sup {minus}12} cm{sup 2}, which makes this a particularly difficult interval to remediate. Thus, the challenge for SPSH is to effectively remediate this clay zone by accelerating the removal of TCE and PCE.

  17. DEMONSTRATION BULLETIN: CYCLONE FURNACE SOIL VITRI- FICATION TECHNOLOGY - BABCOCK & WILCOX

    EPA Science Inventory

    Babcock and Wilcox's (B&W) cyclone furnace is an innovative thermal technology which may offer advantages in treating soils containing organics, heavy metals, and/or radionuclide contaminants. The furnace used in the SITE demonstration was a 4- to 6-million Btu/hr pilot system....

  18. Remediation of degraded arable steppe soils in Moldova using vetch as green manure

    NASA Astrophysics Data System (ADS)

    Wiesmeier, M.; Lungu, M.; Hübner, R.; Cerbari, V.

    2015-01-01

    In the Republic of Moldova, non-sustainable arable farming led to severe degradation and erosion of fertile steppe soils (Chernozems). As a result, the Chernozems lost about 40% of their initial amounts of soil organic carbon (SOC). Aim of this study was to remediate degraded arable soils and promote carbon sequestration by implementation of cover cropping and green manuring in Moldova. Thereby, the suitability of the legume hairy vetch (Vicia sativa) as cover crop under the dry, continental climate of Moldova was examined. At two experimental sites, the effect of cover cropping on chemical and physical soil properties as well as on yields of subsequent main crops was determined. The results showed a significant increase of SOC after incorporation of hairy vetch due to a high above- and belowground biomass production that was related with a high input of carbon and nitrogen. A calculation of SOC stocks based on equivalent soil masses revealed a sequestration of around 3 t C ha-1 yr-1 as a result of hairy vetch cover cropping. The buildup of SOC was associated with an improvement of the soil structure as indicated by a distinct decrease of bulk density and a relative increase of macroaggregates at the expense of microaggregates and clods. As a result, yields of subsequent main crops increased by around 20%. Our results indicated that hairy vetch is a promising cover crop to remediate degraded steppe soils, control soil erosion and sequestrate substantial amounts of atmospheric C in arable soils of Moldova.

  19. Soil remediation by surface heating and vacuum extraction

    SciTech Connect

    Stegemeir, G.L.; Vinegar, H.J.

    1995-12-01

    A novel in-situ, thermal-vacuum method has been developed to remove contaminants from near-surface soils and pavements. Heat is supplied to the soil by downward conduction from a surface heater. Vaporized products are collected under an impermeable sheet into a vacuum system for further treatment or disposal.

  20. [Effect of limestone and magnesite application on remediation of acidified forest soil in Chongqing, China].

    PubMed

    Yang, Yong-sen; Duan, Lei; Jin, Teng; Zhao, Da-wei; Zhang, Dong-bao; Hao, Ji-ming

    2006-09-01

    Effect of limestone and magnesite application on remediation of a typical acidified soil under a masson pine (Pinus massoniana) forest at Tieshanping, Chongqing in southwest China was studied through field experiments. The changes of soil water chemistry in different layers within one year after application of limestone or magnesite indicated that the remediation agents leaded to the recovery of acidified soil by significant increase of pH value and concentration of relative cation, i.e., Ca2+ or Mg2+, and notable decrease of inorganic monomeric aluminum (Ali). However, the accelerated leaching of NO3- and SO4(2-) might somewhat counteract the positive effects. Since the limestone powder applied was much finer and thus more soluble than the magnesite powder, it seemed that the addition of limestone was more effective than that of magnesite. However, the application of magnesite could probably improve the nutrient uptake and growth of plant, and thus limestone and magnesite should be used together. The change of soil water chemistry was much more notable in upper layer of soil than lower, which means that it will take long time to achieve the whole profile soil remediation. PMID:17117649

  1. IS REMOVAL THE ONLY OPTION: IN SITU REMEDIATION OF METAL CONTAMINATED SOILS

    EPA Science Inventory

    The In-place Inactivation and Natural Ecological Restoration Technologies (IINERT) Soil-Metals Action Team was established in 11/95 as one of several Action Teams under the USEPA Remediation Technologies Development Forum (RTDF). Its primary goal was to examine in situ remediatio...

  2. IN-SITU REMEDIATION OF CHROMIUM- CONTAMINATED SOILS AND SEDIMENTS USING SODIUM DITHIONITE: SYMPOSIUM/CONFERENCE

    EPA Science Inventory

    SYMPOS/CONF NRMRL-ADA-01163 Paul*, C.J., Khan*, F.A., and Puls*, R.W. In-Situ Remediation of Chromium-Contaminated Soils and Sediments Using Sodium Dithionite. CD-ROM, GWPC Annual Forum, Reno, NV, ...

  3. CONTROL TECHNOLOGIES FOR REMEDIATION OF CONTAMINATED SOIL AND WASTE DEPOSITS AT SUPERFUND LEAD BATTERY RECYCLING SITES

    EPA Science Inventory

    This paper primarily addresses remediation of contaminated soils and waste deposits at defunct lead-acid battery recycling sites (LBRS) via immobilization and separation processes. A defunct LBRS is a facility at which battery breaking, secondary lead smelting, or both operations...

  4. CONTROL TECHNOLOGIES FOR REMEDIATION OF CONTAMINATED SOIL AND WASTE DEPOSITS AT SUPERFUND LEAD BATTERY SITES

    EPA Science Inventory

    This paper primarily addresses remediation of contaminated soils and waste deposits at defunct lead-acid battery recycling sites (LBRS) via immobilization and separation processes. efunct LBRS is a facility at which battery breaking, secondary lead smelting, or both operations we...

  5. Conjunctive effect of CMC-zero-valent iron nanoparticles and FYM in the remediation of chromium-contaminated soils

    NASA Astrophysics Data System (ADS)

    Madhavi, Vemula; Prasad, Tollamadugu Naga Venkata Krishna Vara; Reddy, Balam Ravindra; Reddy, Ambavaram Vijay Bhaskar; Gajulapalle, Madhavi

    2013-04-01

    Chromium is an important industrial metal used in various products and processes but at the same time causing lethal environmental hazards. Remediation of Cr-contaminated soils poses both technological and economic challenges, as conventional methods are often too expensive and difficult to operate. Zero-valent iron particles at nanoscale are proposed to be one of the important reductants of Cr(VI), transforming the same into nontoxic Cr(III). In the present investigation, soils contaminated with Cr(VI) are allowed to react with the various loadings of zero-valent iron nanoparticles (Fe0) for a reaction period of 24 h. Fe0 nanoparticles were synthesized by the reduction of ferrous sulfate in the presence of sodium borohydride and stabilized with carboxy methyl cellulose and were characterized by scanning electron microscopy, energy dispersion spectroscopy, X-ray diffraction, UV-vis spectrophotometer, Fourier transform-infra red spectrophotometer, Raman spectroscopy, dynamic light scattering technique and zeta potential. Further, this work demonstrates the potential utilization of farm yard manure (FYM) and Fe0 nanoparticles in combination and individually for the effective remediation of Cr(VI)-contaminated soils. An increase in the reduction of Cr(VI) from 60 to 80 % was recorded with the increase in the loading of Fe0 nanoparticles from 0.1 to 0.3 mg/100 g individually and in combination with FYM ranging from 50 to 100 mg/100 g soil.

  6. Conjunctive effect of CMC-zero-valent iron nanoparticles and FYM in the remediation of chromium-contaminated soils

    NASA Astrophysics Data System (ADS)

    Madhavi, Vemula; Prasad, Tollamadugu Naga Venkata Krishna Vara; Reddy, Balam Ravindra; Reddy, Ambavaram Vijay Bhaskar; Gajulapalle, Madhavi

    2014-04-01

    Chromium is an important industrial metal used in various products and processes but at the same time causing lethal environmental hazards. Remediation of Cr-contaminated soils poses both technological and economic challenges, as conventional methods are often too expensive and difficult to operate. Zero-valent iron particles at nanoscale are proposed to be one of the important reductants of Cr(VI), transforming the same into nontoxic Cr(III). In the present investigation, soils contaminated with Cr(VI) are allowed to react with the various loadings of zero-valent iron nanoparticles (Fe0) for a reaction period of 24 h. Fe0 nanoparticles were synthesized by the reduction of ferrous sulfate in the presence of sodium borohydride and stabilized with carboxy methyl cellulose and were characterized by scanning electron microscopy, energy dispersion spectroscopy, X-ray diffraction, UV-vis spectrophotometer, Fourier transform-infra red spectrophotometer, Raman spectroscopy, dynamic light scattering technique and zeta potential. Further, this work demonstrates the potential utilization of farm yard manure (FYM) and Fe0 nanoparticles in combination and individually for the effective remediation of Cr(VI)-contaminated soils. An increase in the reduction of Cr(VI) from 60 to 80 % was recorded with the increase in the loading of Fe0 nanoparticles from 0.1 to 0.3 mg/100 g individually and in combination with FYM ranging from 50 to 100 mg/100 g soil.

  7. The Detection and Remediation of Learning Disabilities. Child Welfare Research and Demonstration Project. Final Report.

    ERIC Educational Resources Information Center

    Bechtel, Leland P.

    Reported are the final 2 years of a program which provided identification and remediation services for 60 potentially dyslexic preschool children and 45 dyslexic elementary grade children. Described for the preschool program are materials and evaluative devices and methods of remediation which stressed development of perceptual motor skills,…

  8. Remediation of oil-contaminated soil using the CLEANSOIL technology

    NASA Astrophysics Data System (ADS)

    Zakharchenko, A. V.; Korzhov, Yu. V.; Lapshina, E. D.; Kul'Kov, M. G.; Yarkov, D. M.; Khoroshev, D. I.

    2011-04-01

    Approbation data of the innovative CLEANSOIL technology of soil purification after oil pollution are given. Drainage pipes filled with an adsorbent with microorganisms placed in the soil are used. It is revealed that the content of hydrocarbons under the technological constructions (metal columns and reservoirs) rises in comparison with the open oil-polluted areas. It is shown that the oil is destroyed quicker under the constructions versus in the open areas. The microorganisms better assimilate the n-alkanes with C14 chains than the C32-40 hydrocarbons. The application of a combined technology based on the sorption and reduction of the hydrocarbons by microorganisms makes it possible to quickly reduce the soil pollution by oil products without the soil cover's disturbance.

  9. Biofilm treatment of soil for waste containment and remediation

    SciTech Connect

    Turner, J.P.; Dennis, M.L.; Osman, Y.A.; Chase, J.; Bulla, L.A.

    1997-12-31

    This paper examines the potential for creating low-permeability reactive barriers for waste treatment and containment by treating soils with Beijerinckia indica, a bacterium which produces an exopolysaccharide film. The biofilm adheres to soil particles and causes a decrease in soil hydraulic conductivity. In addition, B. Indica biodegrades a variety of polycyclic aromatic hydrocarbons and chemical carcinogens. The combination of low soil hydraulic conductivity and biodegradation capabilities creates the potential for constructing reactive biofilm barriers from soil and bacteria. A laboratory study was conducted to evaluate the effects of B. Indica on the hydraulic conductivity of a silty sand. Soil specimens were molded with a bacterial and nutrient solution, compacted at optimum moisture content, permeated with a nutrient solution, and tested for k{sub sat} using a flexible-wall permeameter. Saturated hydraulic conductivity (k{sub sat}) was reduced from 1 x 10{sup -5} cm/sec to 2 x 10{sup -8} cm/sec: by biofilm treatment. Permeation with saline, acidic, and basic solutions following formation of a biofilm was found to have negligible effect on the reduced k{sub sat}, for up to three pore volumes of flow. Applications of biofilm treatment for creating low-permeability reactive barriers are discussed, including compacted liners for bottom barriers and caps and creation of vertical barriers by in situ treatment.

  10. Ecopiling: a combined phytoremediation and passive biopiling system for remediating hydrocarbon impacted soils at field scale.

    PubMed

    Germaine, Kieran J; Byrne, John; Liu, Xuemei; Keohane, Jer; Culhane, John; Lally, Richard D; Kiwanuka, Samuel; Ryan, David; Dowling, David N

    2014-01-01

    Biopiling is an ex situ bioremediation technology that has been extensively used for remediating a wide range of petrochemical contaminants in soils. Biopiling involves the assembling of contaminated soils into piles and stimulating the biodegrading activity of microbial populations by creating near optimum growth conditions. Phytoremediation is another very successful bioremediation technique and involves the use of plants and their associated microbiomes to degrade, sequester or bio-accumulate pollutants from contaminated soil and water. The objective of this study was to investigate the effectiveness of a combined phytoremediation/biopiling system, termed Ecopiling, to remediate hydrocarbon impacted industrial soil. The large scale project was carried out on a sandy loam, petroleum impacted soil [1613 mg total petroleum hydrocarbons (TPHs) kg(-1) soil]. The contaminated soil was amended with chemical fertilizers, inoculated with TPH degrading bacterial consortia and then used to construct passive biopiles. Finally, a phyto-cap of perennial rye grass (Lolium perenne) and white clover (Trifolium repens) was sown on the soil surface to complete the Ecopile. Monitoring of important physico-chemical parameters was carried out at regular intervals throughout the trial. Two years after construction the TPH levels in the petroleum impacted Ecopiles were below detectable limits in all but one subsample (152 mg TPH kg(-1) soil). The Ecopile system is a multi-factorial bioremediation process involving bio-stimulation, bio-augmentation and phytoremediation. One of the key advantages to this system is the reduced costs of the remediation process, as once constructed, there is little additional cost in terms of labor and maintenance (although the longer process time may incur additional monitoring costs). The other major advantage is that many ecological functions are rapidly restored to the site and the process is esthetically pleasing. PMID:25601875

  11. Ecopiling: a combined phytoremediation and passive biopiling system for remediating hydrocarbon impacted soils at field scale

    PubMed Central

    Germaine, Kieran J.; Byrne, John; Liu, Xuemei; Keohane, Jer; Culhane, John; Lally, Richard D.; Kiwanuka, Samuel; Ryan, David; Dowling, David N.

    2015-01-01

    Biopiling is an ex situ bioremediation technology that has been extensively used for remediating a wide range of petrochemical contaminants in soils. Biopiling involves the assembling of contaminated soils into piles and stimulating the biodegrading activity of microbial populations by creating near optimum growth conditions. Phytoremediation is another very successful bioremediation technique and involves the use of plants and their associated microbiomes to degrade, sequester or bio-accumulate pollutants from contaminated soil and water. The objective of this study was to investigate the effectiveness of a combined phytoremediation/biopiling system, termed Ecopiling, to remediate hydrocarbon impacted industrial soil. The large scale project was carried out on a sandy loam, petroleum impacted soil [1613 mg total petroleum hydrocarbons (TPHs) kg-1 soil]. The contaminated soil was amended with chemical fertilizers, inoculated with TPH degrading bacterial consortia and then used to construct passive biopiles. Finally, a phyto-cap of perennial rye grass (Lolium perenne) and white clover (Trifolium repens) was sown on the soil surface to complete the Ecopile. Monitoring of important physico-chemical parameters was carried out at regular intervals throughout the trial. Two years after construction the TPH levels in the petroleum impacted Ecopiles were below detectable limits in all but one subsample (152 mg TPH kg-1 soil). The Ecopile system is a multi-factorial bioremediation process involving bio-stimulation, bio-augmentation and phytoremediation. One of the key advantages to this system is the reduced costs of the remediation process, as once constructed, there is little additional cost in terms of labor and maintenance (although the longer process time may incur additional monitoring costs). The other major advantage is that many ecological functions are rapidly restored to the site and the process is esthetically pleasing. PMID:25601875

  12. Cr (VI) remediation by indigenous bacteria in soils contaminated by chromium-containing slag.

    PubMed

    Chai, Liyuan; Huang, Shunhong; Yang, Zhihui; Peng, Bing; Huang, Yan; Chen, Yuehui

    2009-08-15

    Hexavalent chromium (Cr) is a toxic element causing serious environmental threat. Recently, more and more attention is paid to the bio-remediation of Cr (VI) in the contaminated soils. Cr (VI) remediation by indigenous bacteria in soils contaminated by chromium-containing slag at a steel-alloy factory in Hunan Province, China, was investigated in the present study. The results showed that when sufficient nutrients were amended into the contaminated soils, total Cr (VI) concentration declined from the initial value of 462.8 to 10 mg kg(-1) at 10 days and the removal rate was 97.8%. Water soluble Cr (VI) decreased from the initial concentration of 383.8 to 1.7 mg kg(-1). Exchangeable Cr (VI) and carbonates-bound Cr (VI) were removed by 92.6% and 82.4%, respectively. Meanwhile, four Cr (VI) resistant bacterial strains were isolated from the soil under the chromium-containing slag. Only one strain showed a high ability for Cr (VI) reduction in liquid culture. This strain was identified as Pannonibacter phragmitetus sp. by gene sequencing of 16S rRNA. X-ray photoelectron spectroscope (XPS) analysis indicated that Cr (VI) was reduced into trivalent chromium. The results suggest that indigenous bacterial strains have potential application for Cr (VI) remediation in the soils contaminated by chromium-containing slag. PMID:19246154

  13. [Remediation of chromium (VI) contaminated soils using permeable reactive composite electrodes technology].

    PubMed

    Fu, Rong-Bing; Liu, Fang; Ma, Jin; Zhang, Chang-Bo; He, Guo-Fu

    2012-01-01

    Electrokinetic transport processes have been shown to have potential for the effective removal of heavy metals from soils. However, pH changes near the anode and cathode limit their widespread application in the remediation of contaminated soils. Permeable reactive composite electrodes (PRCE) were made by attaching reactive materials such as Fe(0) and zeolite to the electrodes, and the effects of the composite electrodes on pH control, chromium removal efficiency and Cr speciation changes were studied in the electrokinetic remediation process of Cr( VI) contaminated soil. Composite electrodes consisting of permeable reactive materials gave better pH control and Cr removal efficiency compared to traditional electrodes, and a Fe(0) + zeolite reactive layer in the anode exhibited the best performance compared to zeolite or Fe(0) alone. After 5 days of electrokinetic remediation with a DC voltage of 2 V x cm(-1), the Fe(0) + zeolite reactive layer lowered the pH fluctuation, maintained the soil pH in the range of 5.5 to 8.5, raised the Cr(VI) removal efficiency up to 97% in any soil section, produced lower Cr(III) residues, enhanced the amount of Cr retention up to 8 and 1.8 times respectively, and transformed 98% of the Cr(VI) into lower toxicity Cr(III). This study provides a theoretical basis for the exploitation of permeable reactive composite electrodes which are a practical option for future applications. PMID:22452223

  14. Geotechnical behaviour of low-permeability soils in surfactant-enhanced electrokinetic remediation.

    PubMed

    López-Vizcaíno, Rubén; Navarro, Vicente; Alonso, Juan; Yustres, Ángel; Cañizares, Pablo; Rodrigo, Manuel A; Sáez, Cristina

    2016-01-01

    Electrokinetic processes provide the basis of a range of very interesting techniques for the remediation of polluted soils. These techniques consist of the application of a current field in the soil that develops different transport mechanisms capable of mobilizing several types of pollutants. However, the use of these techniques could generate nondesirable effects related to the geomechanical behavior of the soil, reducing the effectiveness of the processes. In the case of the remediation of polluted soils with plasticity index higher than 35, an excessive shrinkage can be observed in remediation test. For this reason, the continued evaporation that takes place in the sample top can lead to the development of cracks, distorting the electrokinetic transport regime, and consequently, the development of the operation. On the other hand, when analyzing silty soils, in the surroundings of injection surfactant wells, high seepages can be generated that give rise to the development of piping processes. In this article methods are described to allow a reduction, or to even eliminate, both problems. PMID:26488188

  15. In situ remediation of soils contaminated with toxic metal ions using microwave energy.

    PubMed

    Abramovitch, Rudolph A; ChangQing, Lu; Hicks, Evan; Sinard, Joseph

    2003-12-01

    Following onto our work on the in situ remediation of soils contaminated with PAH's, PCB's and other polychlorinated organic compounds using microwave energy, we now report a preliminary investigation on the in situ remediation of soils contaminated with toxic metal ions: Cd(II), Mn(II), Th(IV), Cr(III) and mainly Cr(VI). The soil is partially vitrified in the process, and extraction with hot (70 degrees C) 35% nitric acid for 4.5 h leads to the recovery of very small amounts of the metals which had been spiked into the clean soil: Cd, Mn, and Cr(III) are completely immobilized (unextractable), Th is mostly unextractable, and Cr(VI) partially extractable at very high levels of spiking, but almost completely unextractable using the US EPA Toxicity Characteristic Leaching Procedure. This suggests that contaminated soils which are not going to be used for agricultural purposes can be remediated safely to preset depths without fear of the toxic metal ions leaching out for a long time. PMID:14512111

  16. 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

  17. 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.

  18. Monitoring the Remediation of Salt-Affected Soils and Groundwater

    NASA Astrophysics Data System (ADS)

    Bentley, L. R.; Callaghan, M. V.; Cey, E. E.

    2008-12-01

    Salt-affected soil is one of the most common environmental issues facing the petroleum hydrocarbon industry. Large quantities of brines are often co-produced with gas and oil and have been introduced into the environment through, for example, flare pits, drilling operations and pipe line breaks. Salt must be flushed from the soil and tile drain systems can be used to collect salt water which is then be routed for disposal. A flushing experiment over a 2 m deep tile drain system is being monitored by arrays of tensiometers, repeated soil coring, direct push electrical conductivity profiles (PTC), electromagnetic surveys and electrical resistivity tomography (ERT) surveys. Water table elevation is monitored with pressure transducers. Thermocouple arrays provide temperature profiles that are used to adjust electrical conductivity data to standard temperature equivalents. A 20 m by 20 m plot was deep tilled and treated with soil amendments. Numerous infiltration tests were conducted inside and outside the plot area using both a tension infiltrometer and Guelph permeameter to establish changes in soil hydraulic properties and macroporosity as a result of deep tillage. The results show that till greatly diminished the shallow macroporosity and increased the matrix saturated hydraulic conductivity. A header system is used to evenly flood the plot with 10 m3 of water on each of three consecutive days for an approximate total of 7.5 cm of water. The flood event is being repeated four times over a period of 6 weeks. Baseline PTC and ERT surveys show that the salt is concentrated in the upper 2 to 3 m of soil. Tensiometer data show that the soil at 30 cm depth responds within 2 to 3 hours to flooding events once the soil is wetted and begins to dry again after one week. Soil suction at 1.5 m does not show immediate response to the daily flooding events, but is steadily decreasing in response to the flooding and rainfall events. An ERT survey in October will provide the first

  19. Use of phytoremediation and biochar to remediate heavy metal polluted soils: a review

    NASA Astrophysics Data System (ADS)

    Paz-Ferreiro, J.; Lu, H.; Fu, S.; Méndez, A.; Gascó, G.

    2013-11-01

    Anthropogenic activities are resulting in an increase on the use and extraction of heavy metals. Heavy metals cannot be degraded and hence accumulate in the environment having the potential to contaminate the food chain. This pollution threatens soil quality, plant survival and human health. The remediation of heavy metals deserves attention, but it is impaired by the cost of these processes. Phytoremediation and biochar are two sound environmental technologies which could be at the forefront to mitigate soil pollution. This review provides an overview of the current state of knowledge phytoremediation and biochar application to remediate heavy metal contaminated soils, discussing the advantages and disadvantages of both individual approaches. Research to date has attempted only in a limited number of occasions to combine both techniques, however we discuss the potential advantages of combining both remediation techniques and the potential mechanisms involved in the interaction between phytoremediators and biochar. We identified specific research needs to ensure a sustainable use of phytoremediation and biochar as remediation tools.

  20. Integrating removal actions and remedial actions: Soil and debris management at the Fernald Environmental Management Project

    SciTech Connect

    Goidell, L.C.; Hagen, T.D.; Strimbu, M.J.; Dupuis-Nouille, E.M.; Taylor, A.C.; Weese, T.E.; Yerace, P.J.

    1996-02-01

    Since 1991, excess soil and debris generated at the Fernald Environmental management Project (FEMP) have been managed in accordance with the principles contained in a programmatic Removal Action (RvA) Work Plan (WP). This plan provides a sitewide management concept and implementation strategy for improved storage and management of excess soil and debris over the period required to design and construct improved storage facilities. These management principles, however, are no longer consistent with the directions in approved and draft Records of Decision (RODs) and anticipated in draft RODs other decision documents. A new approach has been taken to foster improved management techniques for soil and debris that can be readily incorporated into remedial design/remedial action plans. Response, Compensation and Liability Act (CERCLA) process. This paper describes the methods that were applied to address the issues associated with keeping the components of the new work plan field implementable and flexible; this is especially important as remedial design is either in its initial stages or has not been started and final remediation options could not be precluded.

  1. Evaluation of a Chemical Fixation Technique for Remediation of Soils Contaminated with Arsenic Trioxide

    NASA Astrophysics Data System (ADS)

    Donahoe, R. J.; Yang, L.; Graham, E. Y.; Redwine, J. C.

    2004-12-01

    The results of an experimental study designed to test a chemical fixation technique for remediation of arsenic-contaminated soils are reported. Soil samples were collected from two industrial sites where herbicide application contaminated the soil with arsenic trioxide. Weathering has redistributed and changed the speciation of the arsenic and caused contamination of soil water and groundwater. Remediation techniques requiring excavation of the affected soil are impractical due to the lack of site access for heavy equipment and the large area impacted. To address these concerns, an in situ treatment method was developed and tested in laboratory experiments. Column experiments were conducted to evaluate the effectiveness of the soil treatment method. Homogenized soil samples from each site were packed into duplicate 4"x18" Plexiglas columns and treated with ferrous sulfate solution using a flow rate of 2 ml/min until iron breakthrough was achieved. Another pair of packed columns was leached with DDI water to provide baseline data for the effect of the treatment solution matrix on arsenic mobility. All soil column effluents showed an initial spike of arsenic after onset of fluid flow; however, the soils undergoing treatment leached less than one half the amount of arsenic leached from the soil by DDI water. When the soil became saturated with the ferrous sulfate treatment solution, effluent solution arsenic concentrations fell below detectable levels. After breakthrough of the treatment solution was achieved, the treated soil columns were allowed to drain and cure for 7 days. One treated soil column and one untreated soil column were then continuously leached with EPA Method 1312 SPLP fluid to observe the effect of treatment on the mobility of arsenic. The second set of treated and untreated soil columns was also leached with SPLP fluid, but in a manner designed to simulate periodic rainfall events. Preliminary experimental results show that ferrous sulfate treatment

  2. Modern Sorters for Soil Segregation on Large Scale Remediation Projects

    SciTech Connect

    Shonka, J.J.; Kelley, J.E.; O'Brien, J.M.

    2008-01-15

    In the mid-1940's, Dr. C. Lapointe developed a Geiger tube based uranium ore scanner and picker to replace hand-cobbing. In the 1990's, a modern version of the Lapointe Picker for soil sorting was developed around the need to clean the Johnston Atoll of plutonium. It worked well with sand, but these systems are ineffective with soil, especially with wet conditions. Additionally, several other constraints limited throughput. Slow moving belts and thin layers of material on the belt coupled with the use of multiple small detectors and small sorting gates make these systems ineffective for high throughput. Soil sorting of clay-bearing soils and building debris requires a new look at both the material handling equipment, and the radiation detection methodology. A new class of Super-Sorters has attained throughput of one hundred times that of the old designs. Higher throughput means shorter schedules which reduce costs substantially. The planning, cost, implementation, and other site considerations for these new Super-Sorters are discussed. Modern soil segregation was developed by Ed Bramlitt of the Defense Nuclear Agency for clean up at Johnston Atoll. The process eventually became the Segmented Gate System (SGS). This system uses an array of small sodium iodide (NaI) detectors, each viewing a small volume (segment), that control a gate. The volume in the gate is approximately one kg. This system works well when the material to be processed is sand; however, when the material is wet and sticky (soils with clays) the system has difficulty moving the material through the gates. Super-Sorters are a new class of machine designed to take advantage of high throughput aggregate processing conveyors, large acquisition volumes, and large NaI detectors using gamma spectroscopy. By using commercially available material handling equipment, the system can attain processing rates of up to 400 metric tons/hr with spectrum acquisition approximately every 0.5 sec, so the acquisition

  3. Biological remediation of polynuclear aromatic hydrocarbon contaminated soils using Acinetobacter sp.

    SciTech Connect

    Joshi, M.M.; Lee, S.

    1996-03-01

    Soils contaminated with polynuclear aromatic hydrocarbons (PAHs) pose a hazard to life. The remediation of such sites has been attempted using various methods such as solvent washing, air stripping, incineration, composting, electrokinetic remediation, and supercritical extraction. However, applicability of these physical, chemical, and biological treatment methods or their combination is critically dependent on soil characteristics, nature and level of contamination, site specifications, and economic feasibility, to name a few. Present research is aimed at studying the applicability of biological treatment for decontamination of industrial soil containing PAHs. The current preliminary study included soil analysis, contaminant characterization, and soil treatment using Acinetobacter sp. The soil treatment over a 5-week period, with minimal supplemental nutrient addition, showed removal efficiencies of 80% and more. The effect of initial microbial population in soil on the removal efficiency over a 5-week treatment period was studied. Experiments were designed to compare the removal efficiencies occurring in packed beds versus continuously-stirred tank reactor (CSTR)-type fermentation conditions. This also estimated a conservative range of decontamination efficiencies achievable using minimal control.

  4. Remediation and restoration of contaminated soils for plant growth and establishment

    NASA Astrophysics Data System (ADS)

    Wong, Vanessa

    2014-05-01

    Degradation and contamination of soils is a serious issue, affecting soil and water quality, human health, and plant health and productivity. Degradation of soils can result in the mobilisation of high concentrations of trace metals as a function of both anthropogenic activities which can also be exacerbated by natural processes. Sulfidic sediments frequently underlie coastal floodplains globally. Oxidation of sulfidic sediments can result in the formation of acid sulfate soils and acidification and mobilisation of associated trace metals in soils, sediments and water. The geochemical processes which occur in these environments can be similar to those in acid mine drainage environments. For example, oxidation of sulfides following surface mining for coal can also result in low pH and high concentrations of trace metals in waste material. Remediation and restoration of such sites for plant growth and establishment can be challenging due to the geochemical characteristics of the soils and sediments. Remediation of oxidised sulfidic sediments on coastal floodplains and mine sites both require an increase in soil pH via incorporation of alkaline materials, and addition of nutrients via organic amendments. This paper presents the findings from two case studies on the remediation of contaminated acidic environments on i) a coastal floodplain, and ii) a coal mine site. We found that addition of lime and organic material increased pH and decreased trace metal concentrations in the coastal floodplain sediments. Organic carbon increased due to the incorporation of additional organic material and increased plant growth. Similarly, pH decreased and trace metal concentrations in leachate also decreased following additions of alkaline wood chip waste and compost in the mine site rehabilitation trials. Plant growth increased with increasing volumes of compost addition. These results, and those presented in SSS8.3 highlight the importance of appropriate ameliorants in the

  5. 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

  6. SURFACTANT ENHANCED REMEDIATION OF SOIL COLUMNS CONTAMINATED BY RESIDUAL TETRACHLOROETHYLENE

    EPA Science Inventory

    The ability of aqueous surfactant solutions to recover tetrachloroethylene (PCE) entrapped in Ottawa sand was evaluated in four column experiments. Residual PCE was emplaced by injecting 14C-labeled PCE into water-saturated soil columns and displacing the free product ...

  7. Environmental implications of soil remediation using the Fenton process.

    PubMed

    Villa, Ricardo D; Trovó, Alam G; Nogueira, Raquel F Pupo

    2008-03-01

    This work evaluates some collateral effects caused by the application of the Fenton process to 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) and diesel degradation in soil. While about 80% of the diesel and 75% of the DDT present in the soil were degraded in a slurry system, the dissolved organic carbon (DOC) in the slurry filtrate increased from 80 to 880mgl(-1) after 64h of reaction and the DDT concentration increased from 12 to 50microgl(-1). Experiments of diesel degradation conducted on silica evidenced that soluble compounds were also formed during diesel oxidation. Furthermore, significant increase in metal concentrations was also observed in the slurry filtrate after the Fenton treatment when compared to the control experiment leading to excessive concentrations of Cr, Ni, Cu and Mn according to the limits imposed for water. Moreover, 80% of the organic matter naturally present in the soil was degraded and a drastic volatilization of DDT and 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene was observed. Despite the high percentages of diesel and DDT degradation in soil, the potential overall benefits of its application must be evaluated beforehand taking into account the metal and target compounds dissolution and the volatilization of contaminants when the process is applied. PMID:18068206

  8. DEMONSTRATION OF STEAM HEATING FOR REMEDIATION OF DENSE NON-AQUEOUS PHASE LIQUID (DNAPL)

    EPA Science Inventory

    Several technologies were used to evaluate their performances in removing the source of DNAPL, chlorinated solvents, such as trichloroethylene (TCE), from Launch Complex 34, Cape Canaveral Air Station. This project evaluated steam injection as a remediation technology.

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

    SciTech Connect

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

    1999-06-01

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

  10. Ricinus communis L. A Value Added Crop for Remediation of Cadmium Contaminated Soil.

    PubMed

    Bauddh, Kuldeep; Singh, Kripal; Singh, Rana P

    2016-02-01

    Heavy metal pollution of soil is a global environmental problem and therefore its remediation is of paramount importance. Cadmium (Cd) is a potential toxicant to living organisms and even at very low concentrations. This study was aimed to assess the effectiveness of Ricinus communis for remediation of Cd contaminated soils. For this, growth and biomass of R. communis and Cd accumulation, translocation and partitioning in different plant parts were investigated after 8 months of plant growth in Cd contaminated soil (17.50 mg Cd kg−1 soil). Eight months old plants stabilized 51 % Cd in its roots and rest of the metal was transferred to the stem and leaves. There were no significant differences in growth, biomass and yield between control and Cd treated plants, except fresh weight of shoots. The seed yield per plant was reduced only by 5 % of Cd contaminated plants than control. The amount of Cd translocated to the castor seeds was nominal i.e. 0.007 µg Cd g−1 seeds. The bioconcentration factor reduced significantly in shoots and seeds in comparison to roots. The data indicates that R. communis is highly tolerant to Cd contamination and can be used for remediation of heavy metal polluted sites. PMID:26464392

  11. Remediation of a historically Pb contaminated soil using a model natural Mn oxide waste.

    PubMed

    McCann, Clare M; Gray, Neil D; Tourney, Janette; Davenport, Russell J; Wade, Matthew; Finlay, Nina; Hudson-Edwards, Karen A; Johnson, Karen L

    2015-11-01

    A natural Mn oxide (NMO) waste was assessed as an in situ remediation amendment for Pb contaminated sites. The viability of this was investigated using a 10 month lysimeter trial, wherein a historically Pb contaminated soil was amended with a 10% by weight model NMO. The model NMO was found to have a large Pb adsorption capacity (qmax 346±14 mg g(-1)). However, due to the heterogeneous nature of the Pb contamination in the soils (3650.54-9299.79 mg kg(-1)), no treatment related difference in Pb via geochemistry could be detected. To overcome difficulties in traditional geochemical techniques due to pollutant heterogeneity we present a new method for unequivocally proving metal sorption to in situ remediation amendments. The method combines two spectroscopic techniques; namely electron probe microanalysis (EPMA) and X-ray photoelectron spectroscopy (XPS). Using this we showed Pb immobilisation on NMO, which were Pb free prior to their addition to the soils. Amendment of the soil with exogenous Mn oxide had no effect on microbial functioning, nor did it perturb the composition of the dominant phyla. We conclude that NMOs show excellent potential as remediation amendments. PMID:26073590

  12. Incineration of explosive contaminated soil as a means of site remediation. Technical report

    SciTech Connect

    Major, M.A.; Amos, J.C.

    1992-11-24

    Large scale releases of explosive contaminated water have occurred in connection with manufacture of explosives, with load assembly and pack operations and at centers for the disassembly and recycle of munitions. The most serious contamination is at sites where explosive contaminated pink water was discarded in unlined evaporation lagoons. Sediments in pink water lagoons normally contain a high concentration of explosive and contamination of ground-water is usually the result. In an effort to remediate this hazard, the U.S. Army has chosen incineration of the contaminated soil as the best means of remediation. Although there is general agreement as to the superiority of incineration for this purpose, the process is complex and environmental, legal and financial questions remain.... Incineration, TNT, RDX, Lead, Mercury, Cadmium, RCRA, Remediation.

  13. The Office of Groundwater & Soil Remediation Fiscal Year 2011 Research & Development Program

    SciTech Connect

    Gerdes, Kurt D.; Chamberlain, Skip; Aylward, R. S.; Cercy, Mike; Seitz, Roger; Ramirez, Rosa; Skubal, Karen L.; Marble, Justin; Wellman, Dawn M.; Bunn, Amoret L.; Liang, Liyuan; Pierce, Eric M.

    2011-03-02

    The U.S. Department of Energy's (DOE) Office of Groundwater and Soil Remediation supports technology development and technical assistance for the remediation of environments contaminated by legacy nuclear waste. The core of the program is centered on delivering proactive, responsive expertise and technologies with highly-leveraged, carefully selected investments that maximum impact on life-cycle cleanup costs and risks across the DOE complex. The program currently focuses on four main priorities: improved sampling and characterization strategies, advanced predictive capabilities, enhanced remediation methods, and improved long-term performance evaluation and monitoring. In FY 2010, the program developed a detailed research and development (R and D) plan in support of a larger initiative to integrate R and D efforts across EM. This paper provides an overview of the priority action areas and the program's near-term technical direction.

  14. The Office of Groundwater & Soil Remediation Fiscal Year 2011 Research & Development Program

    SciTech Connect

    Pierce, Eric M

    2011-01-01

    The U.S. Department of Energy s (DOE) Office of Groundwater and Soil Remediation supports technology development and technical assistance for the remediation of environments contaminated by legacy nuclear waste. The core of the program is centered on delivering proactive, responsive expertise and technologies with highly-leveraged, carefully selected investments that maximize impact on life-cycle cleanup costs and risks across the DOE complex. The program currently focuses on four main priorities: improved sampling and characterization strategies, advanced predictive capabilities, enhanced remediation methods, and improved long-term performance evaluation and monitoring. In FY 2010, the program developed a detailed research and development (R&D) plan in support of a larger initiative to integrate R&D efforts across EM. This paper provides an overview of the high priority action areas and the program s near-term technical direction.

  15. Remediation of degraded arable steppe soils in Moldova using vetch as green manure

    NASA Astrophysics Data System (ADS)

    Wiesmeier, M.; Lungu, M.; Hübner, R.; Cerbari, V.

    2015-05-01

    In the Republic of Moldova, non-sustainable arable farming led to severe degradation and erosion of fertile steppe soils (Chernozems). As a result, the Chernozems lost about 40% of their initial amounts of soil organic carbon (SOC). The aim of this study was to remediate degraded arable soils and promote carbon sequestration by implementation of cover cropping and green manuring in Moldova. Thereby, the suitability of the legume hairy vetch (Vicia sativa) as cover crop under the dry continental climate of Moldova was examined. At two experimental sites, the effect of cover cropping on chemical and physical soil properties as well as on yields of subsequent main crops was determined. The results showed a significant increase of SOC after incorporation of hairy vetch mainly due to increases of aggregate-occluded and mineral-associated OC. This was related to a high above- and belowground biomass production of hairy vetch associated with a high input of carbon and nitrogen into arable soils. A calculation of SOC stocks based on equivalent soil masses revealed a sequestration of around 3 t C ha-1yr-1 as a result of hairy vetch cover cropping. The buildup of SOC was associated with an improvement of the soil structure as indicated by a distinct decrease of bulk density and a relative increase of macroaggregates at the expense of microaggregates and clods. As a result, yields of subsequent main crops increased by around 20%. Our results indicated that hairy vetch is a promising cover crop to remediate degraded steppe soils, control soil erosion and sequester substantial amounts of atmospheric C in arable soils of Moldova.

  16. DDT remediation in contaminated soils: a review of recent studies.

    PubMed

    Sudharshan, Simi; Naidu, Ravi; Mallavarapu, Megharaj; Bolan, Nanthi

    2012-11-01

    Over the past few decades significant progress has been made in research on DDT degradation in the environment. This review is an update of some of the recent studies on the degradation and biodegradation pathways of DDT and its metabolites, particularly in soils. The latest reports on human toxicity shows that DDT intake is still occurring even in countries that banned its use decades ago. Ageing, sequestration and formation of toxic metabolites during the degradation processes pose environmental challenges and result in difficulties in bioremediation of DDT contaminated soils. Degradation enhancement strategies such as the addition of chelators, low molecular organic acids, co-solvent washing and the use of sodium and seaweeds as ameliorant have been studied to accelerate degradation. This review describes and discusses the recent challenges and degradation enhancement strategies for DDT degradation by potentially cost effective procedures based on bioremediation. PMID:22907383

  17. Electrical Resistivity Tomography Monitoring of Soil Remediation for a Garbage Dump

    NASA Astrophysics Data System (ADS)

    shi, X.; Luo, Z.; Zhang, Y.; Fu, Q.; Xu, Z.

    2011-12-01

    Electrical resistivity tomography (ERT) survey was firstly used to investigate the distribution of contaminated soil in a garbage dump area, Wuhan city, China. The result shows that sulfated soil resistivity is about 4 to 7 ohm-m, which is relatively lower than normal soil resistivity of about 15 to 25 ohm-m. The distribution of contaminated soil was delineated using ERT images. Then, ERT survey was carried out in this area for monitoring of remediation of contaminated soil and groundwater. Werner measurements with 60 electrodes of 1 m spacing were taken during the 9-well oxygen injection and nutrition liquid injection period. The difference of apparent resistivity between before gas injection and after gas injection was used to delineate the channel of gas and the trace of gas migration in the porous garbage dump. The electrical resitivity changes between before and after nutrition liquid injection were used to analyze the liquid migration and distribution. The dynamic procedures of gas and water migration are outlined. The results suggest that ERT is a powerful technique for monitoring of soil remediation.

  18. Soil washing as a potential remediation technology for contaminated DOE sites

    SciTech Connect

    Devgun, J.S.; Beskid, N.J. ); Natsis, M.E. ); Walker, J.S. )

    1993-01-01

    Frequently detected contaminants at US Department of Energy (DOE) sites include radionuclides, heavy metals, and chlorinated hydrocarbons. Remediation of these sites requires application of several technologies used in concert with each other, because no single technology is universally applicable. Special situations, such as mixed waste, generally require innovative technology development. This paper, however, focuses on contaminated soils, for which soil washing and vitrification technologies appear to have wide ranging application potential. Because the volumes of contaminated soils around the DOE complex are so large, soil washing can offer a potentially inexpensive way to effect remediation or to attain waste volume reduction. As costs for disposal of low-level and mixed wastes continue to rise, it is likely that volume-reduction techniques and in-situ containment techniques will become increasingly important. This paper reviews the status of the soil washing technology, examines the systems that are currently available, and discusses the potential application of this technology to some DOE sites, with a focus on radionuclide contamination and, primarily, uranium-contaminated soils

  19. Soil washing as a potential remediation technology for contaminated DOE sites

    SciTech Connect

    Devgun, J.S.; Beskid, N.J.; Natsis, M.E.; Walker, J.S.

    1993-03-01

    Frequently detected contaminants at US Department of Energy (DOE) sites include radionuclides, heavy metals, and chlorinated hydrocarbons. Remediation of these sites requires application of several technologies used in concert with each other, because no single technology is universally applicable. Special situations, such as mixed waste, generally require innovative technology development. This paper, however, focuses on contaminated soils, for which soil washing and vitrification technologies appear to have wide ranging application potential. Because the volumes of contaminated soils around the DOE complex are so large, soil washing can offer a potentially inexpensive way to effect remediation or to attain waste volume reduction. As costs for disposal of low-level and mixed wastes continue to rise, it is likely that volume-reduction techniques and in-situ containment techniques will become increasingly important. This paper reviews the status of the soil washing technology, examines the systems that are currently available, and discusses the potential application of this technology to some DOE sites, with a focus on radionuclide contamination and, primarily, uranium-contaminated soils

  20. Remediation of DNAPLs in Low Permeability Soils. Innovative Technology Summary Report

    SciTech Connect

    2000-09-01

    Dense, non-aqueous phase liquid (DNAPL) compounds like trichloroethene (TCE) and perchloroethene (PCE) are prevalent at U. S. Department of Energy (DOE), other government, and industrial sites. Their widespread presence in low permeability media (LPM) poses severe challenges for assessment of their behavior and implementation of effective remediation technologies. Most remedial methods that involve fluid flow perform poorly in LPM. Hydraulic fracturing can improve the performance of remediation methods such as vapor extraction, free-product recovery, soil flushing, steam stripping, bioremediation, bioventing, and air sparging in LPM by enhancing formation permeability through the creation of fractures filled with high-permeability materials, such as sand. Hydraulic fracturing can improve the performance of other remediation methods such as oxidation, reductive dechlorination, and bioaugmentation by enhancing delivery of reactive agents to the subsurface. Hydraulic fractures are typically created using a 2-in. steel casing and a drive point pushed into the subsurface by a pneumatic hammer. Hydraulic fracturing has been widely used for more than 50 years to stimulate the yield of wells recovering oil from rock at great depth and has recently been shown to stimulate the yield of wells recovering contaminated liquids and vapors from LPM at shallow depths. Hydraulic fracturing is an enabling technology for improving the performance of some remedial methods and is a key element in the implementation of other methods. This document contains information on the above-mentioned technology, including description, applicability, cost, and performance data.

  1. A comparison of three bacterial strains for the remediation of town gas soils

    SciTech Connect

    Sauer, N.E.; Akkineni, D.K.; Cutright, T.J.

    1995-12-31

    The contamination of soils from polycyclic aromatic hydrocarbons (PAHs) is widespread. Although PAH contamination still occurs from current industrial processes, accidental spills, and leaking underground storage tanks, the main source of contamination is from abandoned town gas sites. To date there is a conservative estimate of 2500 town gas sites that require remediation. The most cost effective in-situ treatment for these sites is that of bioremediation. Experiments were conducted to compare the efficiencies of three bacterial strains for the remediation of an industrially PAH contaminated soil. Specifically, the efficiencies of Achromobacter sp., Mycobacterium sp., and Nocardia paraffinae were investigated. This paper will address the chemical specificity of each bacterial strains for the PAHs present.

  2. A Critical View of Current State of Phytotechnologies to Remediate Soils: Still a Promising Tool?

    PubMed Central

    Conesa, Héctor M.; Evangelou, Michael W. H.; Robinson, Brett H.; Schulin, Rainer

    2012-01-01

    Phytotechnologies are often shown as an emerging tool to remediate contaminated soils. Research in this field has resulted in many important findings relating to plant and soil sciences. However, there have been scant private and public investments and little commercial success with this technology. Here, we investigate the barriers to the adoption of phytotechnologies and determine whether it is still a fertile area for future research. The terminology used in phytotechnologies includes a confusing mish-mash of terms relating to concepts and processes increasing the difficulty of developing a unique commercial image. We argue that the commercial success of phytotechnologies depends on the generation of valuable biomass on contaminated land, rather than a pure remediation technique that may not compare favourably with the costs of inaction or alternative technologies. Valuable biomass includes timber, bioenergy, feedstock for pyrolosis, biofortified products, or ecologically important species. PMID:22272168

  3. 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.

  4. Modeling in situ ozonation for the remediation of nonvolatile PAH-contaminated unsaturated soils.

    PubMed

    Kim, Jeongkon; Choi, Heechul

    2002-04-01

    Mathematical models were developed to investigate the characteristics of gaseous ozone transport under various soil conditions and the feasibility of in situ ozone venting for the remediation of unsaturated soils contaminated with phenanthrene. On the basis of assumptions for the mass transfer and reactions of ozone, three approaches were considered: equilibrium, kinetic, and lump models. Water-saturation-dependent reactions of gaseous ozone with soil organic matter (SOM) and phenanthrene were employed. The models were solved numerically by using the finite-difference method, and the model parameters were determined by using the experimental data of Hsu [The use of gaseous ozone to remediate the organic contaminants in the unsaturated soils, PhD Thesis, Michigan State Univ., East Lansing, MI, 1995]. The transport of gas-phase ozone is significantly retarded by ozone consumption due to reactions with SOM and phenanthrene, in addition to dissolution. An operation time of 156 h was required to completely remove phenanthrene in a 5-m natural soil column. In actual situations, however, the operation time is likely to be longer than the ideal time because of unknown factors including heterogeneity of the porous medium and the distribution of SOM and contaminant. The ozone transport front length was found to be very limited (< 1 m). The sensitivity analysis indicated that SOM is the single most important factor affecting in situ ozonation for the remediation of unsaturated soil contaminated with phenanthrene. Models were found to be insensitive to the reaction mechanisms of phenathrene with either gas-phase ozone or dissolved ozone. More study is required to quantify the effect of OH* formation on the removal of contaminant and on ozone transport in the subsurface. PMID:11999632

  5. Modeling in situ ozonation for the remediation of nonvolatile PAH-contaminated unsaturated soils.

    SciTech Connect

    Kim, J.; Choi, H.; Environmental Research; Kwangju Inst. of Science and Technology

    2002-04-01

    Mathematical models were developed to investigate the characteristics of gaseous ozone transport under various soil conditions and the feasibility of in situ ozone venting for the remediation of unsaturated soils contaminated with phenanthrene. On the basis of assumptions for the mass transfer and reactions of ozone, three approaches were considered: equilibrium, kinetic, and lump models. Water-saturation-dependent reactions of gaseous ozone with soil organic matter (SOM) and phenanthrene were employed. The models were solved numerically by using the finite-difference method, and the model parameters were determined by using the experimental data of Hsu [The use of gaseous ozone to remediate the organic contaminants in the unsaturated soils, PhD Thesis, Michigan State Univ., East Lansing, MI, 1995]. The transport of gas-phase ozone is significantly retarded by ozone consumption due to reactions with SOM and phenanthrene, in addition to dissolution. An operation time of 156 h was required to completely remove phenanthrene in a 5-m natural soil column. In actual situations, however, the operation time is likely to be longer than the ideal time because of unknown factors including heterogeneity of the porous medium and the distribution of SOM and contaminant. The ozone transport front length was found to be very limited (<1 m). The sensitivity analysis indicated that SOM is the single most important factor affecting in situ ozonation for the remediation of unsaturated soil contaminated with phenanthrene. Models were found to be insensitive to the reaction mechanisms of phenanthrene with either gas-phase ozone or dissolved ozone. More study is required to quantify the effect of OH{sup {sm_bullet}} formation on the removal of contaminant and on ozone transport in the subsurface.

  6. [Effect of flue gas desulfurization gypsum application on remediation of acidified forest soil].

    PubMed

    Luo, Yao; Kang, Rong-Hua; Yu, De-Xiang; Tan, Bing-Quan; Duan, Lei

    2012-06-01

    Effect of flue gas desulfurization gypsum (FGDG) application on remediation of a typical acidified forest soil was studied through field experiments at Tieshanping, Chongqing in southwest China for one year. To evaluate the effect and risk of FGDG application, pH value, major ions and heavy metal of soil water in different soil layers were observed dynamically, and heavy metal contained in soil and FGDG were measured. Results showed that Ca2+ and SO4(-2) concentration of soil water in FGDG plots increased with time, pH value was elevated slightly, and n(Ca)/n(Al) value of annual average increased from 2.16, 1.35 and 0.88 to 2.58, 1.52 and 1.12 compared with control plots. The concentration of As, Cu, Cr, Ni and Zn in soil water was not elevated significantly. However, slight enrichment of Cr, Ni and Zn in some upper soil layers was observed. Consequently, FGDG application can improve acidified forest soil, without obviously heavy metal increasing in soil water. However, risk for heavy metal enrichment still exists, which is need for further study. PMID:22946189

  7. [Current situation and prospect on the remediation of soils contaminated by heavy metals].

    PubMed

    Long, Xinxian; Yang, Xiao'e; Ni, Wuzhong

    2002-06-01

    Physio-chemical techniques and phytoremediation are the important methods for solving heavy metal pollution of environment. According to the processes and mechanisms of reactions, physio-chemical techniques can be divided into chemical immobilization, soil washing and electrokinetic remediation, while phytoremediation includes phytostabilization, phyto-volatilization and phyto-extraction. The principles, advantages, disadvantages, feasibility and future research trends of the techniques were reviewed. PMID:12216411

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

    SciTech Connect

    Bramlitt, E.; Johnson, N.

    1994-12-31

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

  9. Remediation of soil contaminated with pyrene using ground nanoscale zero-valent iron.

    PubMed

    Chang, Ming-Chin; Shu, Hung-Yee; Hsieh, Wen-Pin; Wang, Min-Chao

    2007-02-01

    The sites contaminated with recalcitrant polycyclic aromatic hydrocarbons (PAHs) are serious environmental problems ubiquitously. Some PAHs have proven to be carcinogenic and hazardous. Therefore, the innovative PAH in situ remediation technologies have to be developed instantaneously. Recently, the nanoscale zero-valent iron (ZVI) particles have been successfully applied for dechlorination of organic pollutants in water, yet little research has investigated for the soil remediation so far. The objective in this work was to take advantage of nanoscale ZVI particles to remove PAHs in soil. The experimental factors such as reaction time, particle diameter and iron dosage and surface area were considered and optimized. From the results, both microscale and nanoscale ZVI were capable to remove the target compound. The higher removal efficiencies of nanoscale ZVI particles were obtained because the specific surface areas were about several dozens larger than that of commercially microscale ZVI particles. The optimal parameters were observed as 0.2 g iron/2 mL water in 60 min and 150 rpm by nanoscale ZVI. Additionally, the results proved that nanoscale ZVI particles are a promising technology for soil remediation and are encouraged in the near future environmental applications. Additionally, the empirical equation developed for pyrene removal efficiency provided the good explanation of reaction behavior. Ultimately, the calculated values by this equation were in a good agreement with the experimental data. PMID:17355083

  10. Potential of weed species applied to remediation of soils contaminated with heavy metals.

    PubMed

    Wei, Shu-He; Zhou, Qi-Xing; Wang, Xin; Cao, Wei; Ren, Li-Ping; Song, Yu-Fang

    2004-01-01

    To screen out a series of ideal plants that can effectively remedy contaminated soils by heavy metals is the main groundwork of phytoremediation engineering and the first step of its commercial application on a large scale. In this study, accumulation and endurance of 45 weed species in 16 families from an agricultural site were in situ examined by using the pot-culture field experiment, and the remediation potential of some weed species with high accumulation of heavy metals was assayed. The results showed that Solanum nigrum and Conyza canadensis can not only accumulate high concentration of Cd, but also strongly endure to single Cd and Cd-Pb-Cu-Zn combined pollution. Thus 2 weed species can be regarded as good hyperaccumulators for the remediation of Cd-contaminated soils. Although there were high Cd-accumulation in Artemigia selengensis, Znula britannica and Cephalanoplos setosum, their biomass was adversely affected due to action of heavy metals in the soils. If the problem of low endurance to heavy metals can be solved by a reinforcer, 3 weed species can be perhaps applied commercially. PMID:15559831

  11. Remediation of soil contaminated with pyrene using ground nanoscale zero-valent iron

    SciTech Connect

    Ming-Chin Chang; Hung-Yee Shu; Wen-Pin Hsieh; Min-Chao Wang

    2007-02-15

    The sites contaminated with recalcitrant polycyclic aromatic hydrocarbons (PAHs) are serious environmental problems ubiquitously. Some PAHs have proven to be carcinogenic and hazardous. Therefore, the innovative PAH in situ remediation technologies have to be developed instantaneously. Recently, the nanoscale zero-valent iron (ZVI) particles have been successfully applied for dechlorination of organic pollutants in water, yet little research has investigated for the soil remediation so far. The objective in this work was to take advantage of nanoscale ZVI particles to remove PAHs in soil. The experimental factors such as reaction time, particle diameter and iron dosage and surface area were considered and optimized. From the results, both microscale and nanoscale ZVI were capable to remove the target compound. The higher removal efficiencies of nanoscale ZVI particles were obtained because the specific surface areas were about several dozens larger than that of commercially microscale ZVI particles. The optimal parameters were observed as 0.2 g iron/2 mL water in 60 min and 150 rpm by nanoscale ZVI. Additionally, the results proved that nanoscale ZVI particles are a promising technology for soil remediation and are encouraged in the near future environmental applications. Additionally, the empirical equation developed for pyrene removal efficiency provided the good explanation of reaction behavior. Ultimately, the calculated values by this equation were in a good agreement with the experimental data. 19 refs., 9 figs., 2 tabs.

  12. Some Case Studies on Metal-Microbe Interactions to Remediate Heavy Metals- Contaminated Soils in Korea

    NASA Astrophysics Data System (ADS)

    Chon, Hyo-Taek

    2015-04-01

    Conventional physicochemical technologies to remediate heavy metals-contaminated soil have many problems such as low efficiency, high cost and occurrence of byproducts. Recently bioremediation technology is getting more and more attention. Bioremediation is defined as the use of biological methods to remediate and/or restore the contaminated land. The objectives of bioremediation are to degrade hazardous organic contaminants and to convert hazardous inorganic contaminants to less toxic compounds of safe levels. The use of bioremediation in the treatment of heavy metals in soils is a relatively new concept. Bioremediation using microbes has been developed to remove toxic heavy metals from contaminated soils in laboratory scale to the contaminated field sites. Recently the application of cost-effective and environment-friendly bioremediation technology to the heavy metals-contaminated sites has been gradually realized in Korea. The merits of bioremediation include low cost, natural process, minimal exposure to the contaminants, and minimum amount of equipment. The limitations of bioremediation are length of remediation, long monitoring time, and, sometimes, toxicity of byproducts for especially organic contaminants. From now on, it is necessary to prove applicability of the technologies to contaminated sites and to establish highly effective, low-cost and easy bioremediation technology. Four categories of metal-microbe interactions are generally biosorption, bioreduction, biomineralization and bioleaching. In this paper, some case studies of the above metal-microbe interactions in author's lab which were published recently in domestic and international journals will be introduced and summarized.

  13. A Multilayered Box Model for Calculating Preliminary RemediationGoals in Soil Screening

    SciTech Connect

    Shan, Chao; Javandel, Iraj

    2004-05-21

    In the process of screening a soil against a certain contaminant, we define the health-risk based preliminary remediation goal (PRG) as the contaminant concentration above which some remedial action may be required. PRG is thus the first standard (or guidance) for judging a site. An over-estimated PRG (a too-large value) may cause us to miss some contaminated sites that can threaten human health and the environment. An under-estimated PRG (a too-small value), on the other hand, may lead to unnecessary cleanup and waste tremendous resources. The PRGs for soils are often calculated on the assumption that the contaminant concentration in soil does not change with time. However, that concentration usually decreases with time as a result of different chemical and transport mechanisms. The static assumption thus exaggerates the long-term exposure dose and results in a too-small PRG. We present a box model that considers all important transport processes and obeys the law of mass conservation. We can use the model as a tool to estimate the transient contaminant concentrations in air, soil and groundwater. Using these concentrations in conjunction with appropriate health risk parameters, we may estimate the PRGs for different contaminants. As an example, we calculated the tritium PRG for residential soils. The result is quite different from, but within the range of, the two versions of the corresponding PRG previously recommended by the U.S. EPA.

  14. Does ochre have the potential to be a remedial treatment for As-contaminated soils?

    PubMed

    Olimah, J A; Shaw, L J; Hodson, M E

    2015-11-01

    Ochre is an iron oxyhydroxide-rich waste that accumulates in water bodies associated with disused mines. Laboratory experiments were conducted to examine the potential of four different ochres to be used as remedial agents for As contaminated soils. The ochres removed As from solution (200 and 500 mg L(-1)) in adsorption experiments at pH 3 and 8 and, when added to As contaminated soil (5% w/w) significantly reduced As release to solution. In both these experiments the highest surface area ochres performed best. The impact of ochre amendments on uptake of As from soil by plants and humans and release of As to ground water was assessed in a year-long incubation study. Ochres increased soil pH and reduced CaCl2 extractable As but had no consistent effect on plant growth, plant As uptake or As extraction in physiologically-based extraction tests. Ochre may be better used for water treatment than soil remediation. PMID:26162334

  15. A new approach to electrokinetic remediation of soils polluted by heavy metals

    NASA Astrophysics Data System (ADS)

    Li, Zhongming; Yu, Ji-Wei; Neretnieks, Ivars

    1996-04-01

    When the electrokinetic method is used to remove metals from soils, metals may precipitate as hydroxides in the region of the soil where pH is raised, which limits the remediation efficiency. The pH rise is caused by the generation of hydroxide ions as a result of electrolysis of water during the remediation. This paper proposes a new technique in which a conductive solution is inserted between the cathode and the soil to be treated. By this approach, the pH in the soil can be kept low so that no metal precipitation will occur. Thus metal ions may migrate out of the soil and precipitate in the inserted solution. Laboratory experiments have been carried out to remove copper and zinc from sand by the proposed technique. The experimental results show that metal removal efficiencies depend on the duration of the treatment and the content of electrolytes in the solution. Metal removal efficiencies of > 96% can be reached for both copper and zinc.

  16. The practical application of remediating soil impacted by salt from produced water

    SciTech Connect

    Cresswell, G.A.; Williams, O.W.

    1995-12-31

    In many geographical areas where crude oil is produced, saltwater is a natural by-product of the oil production stream. The dissolved solids of this produced saltwater varies significantly with geography. Often the higher salinity values are associated with produced water at secondary crude oil recovery waterfloods and on occasion with depletion-drive and water drive primary crude oil recovery. Secondary recovery methods, waterfloods, typically follow many years of primary crude oil production thereby extending the producing life another 20 to 40 years. Many of the major fields producing today have been on stream for more than 50 years. The historical actions associated with these operations, high salt concentrations of the water and the cumulative volumes of saltwater handled all combine to increase the environmental risk of adversely impacting surface. This paper shares some of the experiences one company has encountered in an effort to assess and reduce the economic and environmental risks associated with salt impacted soils at waterfloods. The focus of this paper is on the practical aspects of identifying soil areas impacted before the nationwide improvements in environmental requirements in the mid 1970s and improving the productivity of surface soils. It summarizes how successful remediation approaches have been aligned with soil characteristics and intended surface uses. Remediation approaches have included calcium/sodium exchange, fresh water flushing, and organic additives. Also presented are the precautions used to make sure potential adverse impacts from the salt are not passed from the soil to other media.

  17. Zeta potential of soils with surfactants and its relevance to electrokinetic remediation.

    PubMed

    Kaya, Abidin; Yukselen, Yeliz

    2005-04-11

    There are numerous studies on the application of electrokinetic decontamination technique to remediate heavy metal contaminated fine-grained soils. In recent studies, surfactants have been used to increase the efficiency of contaminant removal. However, there is limited data available on how physicochemical parameters such as zeta potential (zeta) of soils changes in the presence of surfactants. Understanding the zeta potential variations of soils with surfactant addition is important because it controls the direction and magnitude of electro-osmotic permeability, which plays important role on the efficiency of electrokinetic remediation. In this study, zeta potentials of kaolinite, montmorillonite and quartz powder with Li+, Ca+2, Cu+2, Pb+2 and Al+3 in the presence of anionic, cationic and non-ionic surfactants were determined. The results indicate that anionic surfactants produce negative zeta potentials. The other surfactants produce both positive and negative zeta potentials depending on soil type and ion present in the system. The results also indicate that the zeta potential of kaolinite and quartz powder with surfactants showed similar trends; however, the absolute magnitude of the zeta potential of quartz powder is higher than that of kaolinite. The zeta potential of montmorillonite commonly shows a different trend from those of kaolinite and quartz powder. Based on the test results, it is recommended that zeta potential of soils be determined before the electrokinetic decontamination in order to maximize the efficiency of the technique. PMID:15811672

  18. 300-FF-1 operable unit remedial investigation phase II report: Physical separation of soils treatability study

    SciTech Connect

    Not Available

    1994-04-01

    This report describes the approach and results of physical separations treatability tests conducted at the Hanford Site in the North Process Pond of the 300-FF-1 Operable Unit. Physical separation of soils was identified as a remediation alternative due to the potential to significantly reduce the amount of contaminated soils prior to disposal. Tests were conducted using a system developed at Hanford consisting of modified EPA equipment integrated with screens, hoppers, conveyors, tanks, and pumps from the Hanford Site. The treatability tests discussed in this report consisted of four parts, in which an estimated 84 tons of soil was processed: (1) a pre-test run to set up the system and adjust system parameters for soils to be processed; (2) a baseline run to establish the performance of the system - Test No. 1; (3) a final run in which the system was modified as a result of findings from the baseline run - Test No. 2; and (4) water treatment.

  19. Oak Ridge background soils project provides data for remedial action evaluation

    SciTech Connect

    Watkins, D.R.; Lee, S.Y.; Hatmaker, T.L.; McGinn, C.W.; Nourse, B.D.; Schmoyer, R.L.; Burgoa, B.B.; Lietzke, D.A.

    1994-09-01

    Many constituents of potential concern for human health occur naturally at low concentrations in soils. The primary objective of the Background Soil Characterization Project (BSCP) was to provide fully validated and defensible, reservation-wide background concentration data on significant potential contaminants of concern (organics, inorganics, and radionuclides) in natural soils on the Oak Ridge Reservation (ORR). The data are particularly significant for remedial action projects; the data can be used to establish technical guidance and the basis for realistic cleanup requirements at hazardous waste sites on the reservation. Other objectives included providing baseline data for conducting contaminated site assessments and quantifying estimates of human health risk associated with background levels of potentially hazardous constituents in soils.

  20. Remediation application strategies for depleted uranium contaminated soils at the US Army Yuma Proving Ground

    SciTech Connect

    Vandel, D.S.; Medina, S.M.; Weidner, J.R.

    1994-03-01

    The US Army Yuma Proving Ground (YPG), located in the southwest portion of Arizona conducts firing of projectiles into the Gunpoint (GP-20) firing range. The penetrators are composed of titanium and DU. The purpose of this project was to determine feasible cleanup technologies and disposal alternatives for the cleanup of the depleted uranium (DU) contaminated soils at YPG. The project was split up into several tasks that include (a) collecting and analyzing samples representative of the GP-20 soils, (b) evaluating the data results, (c) conducting a literature search of existing proven technologies for soil remediation, and (0) making final recommendations for implementation of this technology to the site. As a result of this study, several alternatives for the separation, treatment, and disposal procedures are identified that would result in meeting the cleanup levels defined by the Nuclear Regulatory Commission for unrestricted use of soils and would result in a significant cost savings over the life of the firing range.

  1. Remediation of metal-contaminated urban soil using flotation technique.

    PubMed

    Dermont, G; Bergeron, M; Richer-Laflèche, M; Mercier, G

    2010-02-01

    A soil washing process using froth flotation technique was evaluated for the removal of arsenic, cadmium, copper, lead, and zinc from a highly contaminated urban soil (brownfield) after crushing of the particle-size fractions >250microm. The metal contaminants were in particulate forms and distributed in all the particle-size fractions. The particle-by-particle study with SEM-EDS showed that Zn was mainly present as sphalerite (ZnS), whereas Cu and Pb were mainly speciated as various oxide/carbonate compounds. The influence of surfactant collector type (non-ionic and anionic), collector dosage, pulp pH, a chemical activation step (sulfidization), particle size, and process time on metal removal efficiency and flotation selectivity was studied. Satisfactory results in metal recovery (42-52%), flotation selectivity (concentration factor>2.5), and volume reduction (>80%) were obtained with anionic collector (potassium amyl xanthate). The transportation mechanisms involved in the separation process (i.e., the true flotation and the mechanical entrainment) were evaluated by the pulp chemistry, the metal speciation, the metal distribution in the particle-size fractions, and the separation selectivity indices of Zn/Ca and Zn/Fe. The investigations showed that a great proportion of metal-containing particles were recovered in the froth layer by entrainment mechanism rather than by true flotation process. The non-selective entrainment mechanism of the fine particles (<20 microm) caused a flotation selectivity drop, especially with a long flotation time (>5 min) and when a high collector dose is used. The intermediate particle-size fraction (20-125 microm) showed the best flotation selectivity. PMID:19959208

  2. Some achievements of the Committee H "Soil Pollution, Degradation and Remediation"

    NASA Astrophysics Data System (ADS)

    Bech, J.

    2012-04-01

    The Soil System Sciences (SSS) Division, created by J. Weber in 2002 in the EGU, consists of 12 Committees, which cover significant topics of basic and applied Soil Science. One of them is the Committee H, dedicated to "Soil Pollution, Degradation and Remediation". This Committee had been active since 2004, and has organised 14 Sessions (i.e. SSS7, 2004, Nice, SSSS7, 2005, Vienna, SSS17, 2006, Vienna, etc. . . until SSS9.1, 2012, the present session). The title of the SSS7 Session (2004, Nice) was the same as the Committee "Soil pollution, degradation and remediation" and received 30 Contributions. The present Session SSS9.1 has received 40 Contributions. Since 2004 the 14 Sessions have included more than 400 Contributions (Oral and Poster) by applicants from more than 40 countries (european and extraeuropean). A good number of these contributions ("in extenso" papers) have been published in international journals. A selection of complete originals from these Sessions have been published in five Special Issues of the Journal of Geochemical Exploration, i.e.: Trace elements in Soils: baseline levels and imbalance (2008), Selenium and Iodine anomalies in Soils and health (2010), Pedogeochemical Mapping of Potentially Toxic Elements (2011), Reclamation of Mining Site Soils (2012) and "Phytoremediation of Polluted Soils" (in press). I conclude this overview our Committee H's work between 2003 and 2012 with a brief discussion of several examples. Finally, I would like to thank the founder of the SSS Division Prof. Dr. J. Weber for his outstanding work, as well as his successors Profs. T. Miano and A. Cerdà for continuing his excellent work.

  3. Remediation of metal polluted hotspot areas through enhanced soil washing--evaluation of leaching methods.

    PubMed

    Fedje, Karin Karlfeldt; Yillin, Li; Strömvall, Ann-Margret

    2013-10-15

    Soil washing offers a permanent remediation alternative for metal polluted sites. In addition, the washed out metals can be recovered from the leachate and re-introduced into the social material cycle instead of landfilled. In this paper, soil, bark and bark-ash washing was tested on four different metal polluted soil and bark samples from hotspots at former industrial sites. Six different leaching agents; HCl, NH4Cl, lactic acid, EDDS and two acidic process waters from solid waste incineration, were tested, discussed and evaluated. For the soil washing processes, the final pH in the leachate strongly influences the metal leachability. The results show that a pH < 2 is needed to achieve a high leaching yield, while <50 w% of most metals were leached when the pH was higher than 2 or below 10. The acidic process waste waters were generally the most efficient at leaching metals from all the samples studied, and as much as 90-100 w% of the Cu was released from some samples. Initial experiments show that from one of these un-purified leachates, Cu metal (>99% purity) could be recovered. After a single leaching step, the metal contents of the soil residues still exceed the maximum limits according to the Swedish guidelines. An additional washing step is needed to reduce the contents of easy soluble metal compounds in the soil residues. The overall results from this study show that soil and bark-ash washing followed by metal recovery is a promising on-site permanent alternative to remediate metal polluted soils and to utilize non-used metal resources. PMID:23811538

  4. DEMONSTRATION BULLETIN: PNEUMATIC FRACTURING EXTRACTION™ AND HOT GAS INJECTION, PHASE I - ACCUTECH REMEDIAL SYSTEMS, INC.

    EPA Science Inventory

    The Pneumatic Fracturing Extraction(PFE) process developed by Accutech Remedial Systems, Inc. makes it possible to use vapor extraction to remove volatile organics at increased rates from a broader range of vadose zones. The low permeability of silts, clays, shales, etc. would ot...

  5. Inorganic materials as ameliorants for soil remediation of metal toxicity to wild mustard (Sinapis arvensis L.).

    PubMed

    Ribeiro Filho, Mateus Rosas; Siqueira, José Oswaldo; Vangronsveld, Jaco; Soares, Cláudio Roberto Fonsêca Sousa; Curi, Nilton

    2011-01-01

    The ameliorating effects of different inorganic materials were investigated on a soil originating from a zinc smelter dumping site contaminated by toxic metals. Wild mustard (Sinapis arvensis L.) was used as a test plant. The soil was amended with different doses of mining sludge, Perferric Red Latosol (LVj), steel shots, cyclonic ash, silifertil, and superphosphate. The most effective amendments improved plant growth with 45% and reduced metal uptake by over 70% in comparison to untreated soil. Reductions in availability as estimated by BaCl2-extractable metals reached up to 90% for Zn and 65% for Cd as compared to unamended soil. These reductions were associated with lower shoot and root metal contents. Shoot Zn content was reduced from 1,369 microg g(-1) in plants grown on untreated soil to 377 microg g(-1) when grown on cyclonic ash amended soil while Cd decreased from 267 to 44 microg g(-1) in steel shots amended soil. Superphosphate addition had no ameliorating effect. On the contrary, it increased BaCl2-extractable amounts of Zn. Considering all parameters we determined, steel shots, cyclonic ash and silifertil are the most promising for remediating metal contaminated soil in the tropics. Further studies evaluating impacts, cost-effectiveness and durability of effects will be conducted. PMID:21598779

  6. A multi-species approach to toxicity assessment of a soil remediation technology

    SciTech Connect

    Gunderson, C.A.; Kostuck, J.M.; Gibbs, M.H.; Napolitano, G.E.; Wicker, L.F.; Richmond, J.E.; Stewart, A.J.

    1994-12-31

    A multi-species terrestrial test system was developed to test the biological effectiveness of composting as a soil-remediation technology. A suite of responses were evaluated across multiple scales to form a chain of evidence predictive of longer-term effects at higher levels. The authors compared responses of soil microorganisms, two soil invertebrates, and three plant species to two compost types (the final product from a US Army explosives composting study, and an uncontaminated reference compost). The authors evaluated plant growth and physiology (photosynthesis, root modulation and symbiotic N2-fixation), invertebrate growth and reproduction, and soil microbial populations. Compost from the contaminated soil inhibited several aspects of plant performance, but produced few adverse effects on invertebrates. An initial lag in invertebrate reproduction in the reference compost, however, suggested differences not associated with residual contamination and highlighted a difficulty inherent in soil toxicity assessment: finding an appropriate reference soil. Nevertheless, the results from this system and complementary shorter-term tests suggested some non-lethal adverse effects from the contaminated-soil compost, primarily to plants. This methodology can bridge the gap between traditional short-term toxicity testing and longer-term field assessments and provide information on ecological effects by explicitly including measurements at several levels of ecological organization.

  7. Remediation aspect of microbial changes of plant rhizosphere in mercury contaminated soil.

    PubMed

    Sas-Nowosielska, Aleksandra; Galimska-Stypa, Regina; Kucharski, Rafał; Zielonka, Urszula; Małkowski, Eugeniusz; Gray, Laymon

    2008-02-01

    Phytoremediation, an approach that uses plants to remediate contaminated soil through degradation, stabilization or accumulation, may provide an efficient solution to some mercury contamination problems. This paper presents growth chamber experiments that tested the ability of plant species to stabilize mercury in soil. Several indigenous herbaceous species and Salix viminalis were grown in soil collected from a mercury-contaminated site in southern Poland. The uptake and distribution of mercury by these plants were investigated, and the growth and vitality of the plants through a part of one vegetative cycle were assessed. The highest concentrations of mercury were found at the roots, but translocation to the aerial part also occurred. Most of the plant species tested displayed good growth on mercury contaminated soil and sustained a rich microbial population in the rhizosphere. The microbial populations of root-free soil and rhizosphere soil from all species were also examined. An inverse correlation between the number of sulfur amino acid decomposing bacteria and root mercury content was observed. These results indicate the potential for using some species of plants to treat mercury contaminated soil through stabilization rather than extraction. The present investigation proposes a practical cost-effective temporary solution for phytostabilization of soil with moderate mercury contamination as well as the basis for plant selection. PMID:17492484

  8. Uranium removal from soils: An overview from the Uranium in Soils Integrated Demonstration program

    SciTech Connect

    Francis, C.W.; Brainard, J.R.; York, D.A.; Chaiko, D.J.; Matthern, G.

    1994-09-01

    An integrated approach to remove uranium from uranium-contaminated soils is being conducted by four of the US Department of Energy national laboratories. In this approach, managed through the Uranium in Soils Integrated Demonstration program at the Fernald Environmental Management Project, Fernald, Ohio, these laboratories are developing processes that selectively remove uranium from soil without seriously degrading the soil`s physicochemical characteristics or generating waste that is difficult to manage or dispose of. These processes include traditional uranium extractions that use carbonate as well as some nontraditional extraction techniques that use citric acid and complex organic chelating agents such as naturally occurring microbial siderophores. A bench-scale engineering design for heap leaching; a process that uses carbonate leaching media shows that >90% of the uranium can be removed from the Fernald soils. Other work involves amending soils with cultures of sulfur and ferrous oxidizing microbes or cultures of fungi whose role is to generate mycorrhiza that excrete strong complexers for uranium. Aqueous biphasic extraction, a physical separation technology, is also being evaluated because of its ability to segregate fine particulate, a fundamental requirement for soils containing high levels of silt and clay. Interactions among participating scientists have produced some significant progress not only in evaluating the feasibility of uranium removal but also in understanding some important technical aspects of the task.

  9. Upscaling Self-Sustaining Treatment for Active Remediation (STAR): Experimental Study of Scaling Relationships for Smouldering Combustion to Remediate Soil

    NASA Astrophysics Data System (ADS)

    Kinsman, L.; Gerhard, J.; Torero, J.; Scholes, G.; Murray, C.

    2013-12-01

    Self-sustaining Treatment for Active Remediation (STAR) is a relatively new remediation approach for soil contaminated with organic industrial liquids. This technology uses smouldering combustion, a controlled, self-sustaining burning reaction, to destroy nonaqueous phase liquids (NAPLs) and thereby render soil clean. While STAR has been proven at the bench scale, success at industrial scales requires the process to be scaled-up significantly. The objective of this study was to conduct an experimental investigation into how liquid smouldering combustion phenomena scale. A suite of detailed forward smouldering experiments were conducted in short (16 cm dia. x 22 cm high), intermediate (16 cm dia. x 127 cm high), and large (97 cm dia. x 300 cm high; a prototype ex-situ reactor) columns; this represents scaling of up to 530 times based on the volume treated. A range of fuels were investigated, with the majority of experiments conducted using crude oil sludge as well as canola oil as a non-toxic surrogate for hazardous contaminants. To provide directly comparable data sets and to isolate changes in the smouldering reaction which occurred solely due to scaling effects, sand grain size, contaminant type, contaminant concentration and air injection rates were controlled between the experimental scales. Several processes could not be controlled and were identified to be susceptible to changes in scale, including: mobility of the contaminant, heat losses, and buoyant flow effects. For each experiment, the propagation of the smouldering front was recorded using thermocouples and analyzed by way of temperature-time and temperature-distance plots. In combination with the measurement of continuous mass loss and gaseous emissions, these results were used to evaluate the fundamental differences in the way the reaction front propagates through the mixture of sand and fuel across the various scales. Key governing parameters were compared between the small, intermediate, and large

  10. Evaluation of the potential of soil remediation by direct multi-channel pulsed corona discharge in soil.

    PubMed

    Wang, Tie Cheng; Qu, Guangzhou; Li, Jie; Liang, Dongli

    2014-01-15

    A novel approach, named multi-channel pulsed corona discharge in soil, was developed for remediating organic pollutants contaminated soil, with p-nitrophenol (PNP) as the model pollutant. The feasibility of PNP degradation in soil was explored by evaluating effects of pulse discharge voltage, air flow rate and soil moisture on PNP degradation. Based on roles of chemically active species and evolution of degradation intermediates, PNP degradation processes were discussed. Experimental results showed that about 89.4% of PNP was smoothly degraded within 60min of discharge treatment at pulse discharge voltage 27kV, soil moisture 5% and air flow rate 0.8Lmin(-1), and the degradation process fitted the first-order kinetic model. Increasing pulse discharge voltage was found to be favorable for PNP degradation, but not for energy yield. There existed appropriate air flow rate and soil moisture for obtaining gratifying PNP degradation efficacy. Roles of radical scavenger and measurement of active species suggested that ozone, H2O2, and OH radicals played very important roles in PNP degradation. CN bond in PNP molecule was cleaved, and the main intermediate products such as hydroquinone, benzoquinone, catechol, phenol, acetic acid, formic acid, oxalic acid, NO2(-) and NO3(-) were identified. Possible pathway of PNP degradation in soil in such a system was proposed. PMID:24295768

  11. Nanobiotechnology for enzymatic remediation and soil carbon sequestration

    SciTech Connect

    Kim, Jungbae; Amonette, James E.; Russell, Colleen K.

    2005-03-13

    We studied the ability of tyrosinase to catalyze the oxidation of various phenolic compounds. As a revolutionary approach to enzyme stabilization, we developed specially-designed nanoporous silica for enzyme immobilization. Our tests show that the active lifetime of the enzymes stabilized in this material can extend to periods as long as several months, which is about a 100-fold increase in stability. The implications of this new approach to enzyme-based bioremedation will be discussed. In soils, the humification process involves phenol oxidation, mediated by tyrosinase, followed by nonenzymatic polymerization of the resulting quinones with amino acids to form humic polymers. We tested the effects of fly ash amendments on a model humification reaction involving tyrosinase and a suite of organic monomers. The combination of fly ashes with tyrosinase increased the amount of polymer formed by several fold. The strong synergetic effect of these ashes when enzyme is present apparently arises from the combined effects of alkaline pH and physical stabilization of the enzyme in porous silica cenospheres.

  12. Application of iron electrode corrosion enhanced electrokinetic-Fenton oxidation to remediate diesel contaminated soils: A laboratory feasibility study

    NASA Astrophysics Data System (ADS)

    Tsai, Tzai-Tang; Sah, Jygau; Kao, Chih-Ming

    2010-01-01

    SummaryDiesel soil contamination on gas stations or refinery plants is a worldwide environmental problem. The main objectives of this study were to (1) evaluate the efficiency of electrokinetic (EK) by using different electrode materials (graphite and iron rods) and electrolytes (tap water, 0.01 M NaCl, and 0.1 M NaCl) on the remediation of diesel contaminated soils, and (2) evaluate the feasibility of total petroleum hydrocarbon-diesel (TPH-D) reducing in soils via EK-Fenton oxidation enhanced by corroded iron electrode. The EK and EK-Fenton experiments were conducted in batch and sand box experiments, respectively. Batch experiments reveal that the most appropriate electrolyte was 0.1 M NaCl when iron electrode was used in the EK system. Sand box experiments indicate that the TPH-D concentration dropped from 10,000 to 300 mg kg -1 when amorphous iron/total iron (Fe o/Fe t) ratio increased from 0.1 to 0.33, with the addition of 8% of H 2O 2 and 0.1 M NaCl after 60 days of EK-Fenton operation. Electrokinetically enhanced oxidation with the presence of both H 2O 2 and Fe 3O 4 (iron electrode corrosion) resulted in higher TPH-D removal efficiency (97%) compared to the efficiencies observed from EK (55%) or Fenton oxidation (27%) alone. This demonstrates that EK-Fenton oxidation catalyzed by iron electrode corrosion is a valuable direction to efficiently and effectively remediate diesel contaminated soils.

  13. Operational strategy for soil concentration predictions of strontium/yttrium-90 and cesium-137 in surface soil at the West Valley Demonstration Project site

    SciTech Connect

    Myers, J.A.

    1995-06-05

    There are difficulties associated with the assessment of the interpretation of field measurements, determination of guideline protocols and control and disposal of low level radioactive contaminated soil in the environmental health physics field. Questions are raised among scientists and in public forums concerning the necessity and high costs of large area soil remediation versus the risks of low-dose radiation health effects. As a result, accurate soil activity assessments become imperative in decontamination situations. The West Valley Demonstration Project (WVDP), a US Department of Energy facility located in West Valley, New York is managed and operated by West Valley Nuclear Services Co., Inc. (WVNS). WVNS has identified contaminated on-site soil areas with a mixed variety of radionuclides (primarily fission product). Through the use of data obtained from a previous project performed during the summer of 1994 entitled ``Field Survey Correlation and Instrumentation Response for an In Situ Soil Measurement Program`` (Myers), the WVDP offers a unique research opportunity to investigate the possibility of soil concentration predictions based on exposure or count rate responses returned from a survey detector probe. In this study, correlations are developed between laboratory measured soil beta activity and survey probe response for the purposes of determining the optimal detector for field use and using these correlations to establish predictability of soil activity levels.

  14. Remediating RDX-contaminated water and soil using zero-valent iron

    SciTech Connect

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

    1998-09-01

    Soil and water contaminated with RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) pose a serious threat to the environment and human health. The objective was to determine the potential for using zero-valent iron (Fe{sup 0}) to remediate RDX-contaminated water and soil. Mixing an aqueous solution of 32 mg RDX L{sup {minus}1} (spiked with {sup 14}C-labeled RDX) with 10 g Fe{sup 0} L{sup {minus}1} resulted in complete RDX destruction within 72 h. Nitroso derivatives of RDX accounted for approximately 26% of the RDX transformed during the first 24 h; these intermediates disappeared within 96 h ad the remaining {sup 14}C products were water soluble and not strongly sorbed by iron surfaces. When RDX-contaminated soil was treated with a single amendment of Fe{sup 0} in a static soil microcosm, more than 60% of the initial {sup 14}C-RDX was recovered as {sup 14}CO{sub 2} after 112 d. Treating surface and subsurface soils containing 3,600 mg RDX kg{sup {minus}1} with 50 g Fe{sup 0} kg{sup {minus}1} at a constant soil water content resulted in a 52% reduction in extractable RDX following 12 mo of static incubation. A second Fe{sup 0} addition at 12 mo further reduced the initial extractable RDX by 71% after 15 mo. These results support the use of zero-valent iron for in situ remediation of RDX-contaminated soil.

  15. Phosphorus Amendment Efficacy for In Situ Remediation of Soil Lead Depends on the Bioaccessible Method.

    PubMed

    Obrycki, John F; Basta, Nicholas T; Scheckel, Kirk; Stevens, Brooke N; Minca, Kristen K

    2016-01-01

    A validated method is needed to measure reductions of in vitro bioaccessible (IVBA) Pb in urban soil remediated with amendments. This study evaluated the effect of in vitro extraction solution pH and glycine buffer on bioaccessible Pb in P-treated soils. Two Pb-contaminated soils (790-1300 mg Pb kg), one from a garden and one from a city lot in Cleveland, OH, were incubated in a bench scale experiment for 1 yr. Six phosphate amendments, including bone meal, fish bone, poultry litter, monoammonium phosphate, diammonium phosphate, and triple superphosphate, were added to containers at two application rates. Lead IVBA was assessed using USEPA Method 1340 and three modified versions of this method. Modifications included using solutions with pH 1.5 and 2.5 as well as using solutions with and without 0.4 mol L glycine. Soil amendments were ineffective in reducing IVBA Pb in these soils as measured by pH 1.5 with glycine buffer. The greatest reductions in IVBA Pb, from 5 to 26%, were found using pH 2.5 extractions. Lead mineral results showed several soil amendments promoted Pb phosphate formation, an indicator of remediation success. A significant negative linear relationship between reduction in IVBA Pb and Pb-phosphate formation was found only for pH 2.5 without glycine extraction solution. A modified USEPA Method 1340 without glycine and using pH 2.5 has the potential to predict P soil treatment efficacy and reductions in bioavailable Pb. PMID:26828158

  16. Electrokinetic delivery of persulfate to remediate PCBs polluted soils: Effect of different activation methods.

    PubMed

    Fan, Guangping; Cang, Long; Gomes, Helena I; Zhou, Dongmei

    2016-02-01

    Persulfate-based in-situ chemical oxidation (ISCO) for the remediation of organic polluted soils has gained much interest in last decade. However, the transportation of persulfate in low-permeability soil is very low, which limits its efficiency in degrading soil pollutants. Additionally, the oxidation-reduction process of persulfate with organic contaminants takes place slowly, while, the reaction will be greatly accelerated by the production of more powerful radicals once it is activated. Electrokinetic remediation (EK) is a good way for transporting persulfate in low-permeability soil. In this study, different activation methods, using zero-valent iron, citric acid chelated Fe(2+), iron electrode, alkaline pH and peroxide, were evaluated to enhance the activity of persulfate delivered by EK. All the activators and the persulfate were added in the anolyte. The results indicated that zero-valent iron, alkaline, and peroxide enhanced the transportation of persulfate at the first stage of EK test, and the longest delivery distance reached sections S4 or S5 (near the cathode) on the 6th day. The addition of activators accelerated decomposition of persulfate, which resulted in the decreasing soil pH. The mass of persulfate delivered into the soil declined with the continuous decomposition of persulfate by activation. The removal efficiency of PCBs in soil followed the order of alkaline activation > peroxide activation > citric acid chelated Fe(2+) activation > zero-valent iron activation > without activation > iron electrode activation, and the values were 40.5%, 35.6%, 34.1%, 32.4%, 30.8% and 30.5%, respectively. The activation effect was highly dependent on the ratio of activator and persulfate. PMID:26347936

  17. Reconnaissance soil geochemistry at the Riverton Uranium Mill Tailings Remedial Action Site, Fremont County, Wyoming

    USGS Publications Warehouse

    Smith, David B.; Sweat, Michael J.

    2012-01-01

    Soil samples were collected and chemically analyzed from the Riverton Uranium Mill Tailings Remedial Action Site, which lies within the Wind River Indian Reservation in Fremont County, Wyoming. Nineteen soil samples from a depth of 0 to 5 centimeters were collected in August 2011 from the site. The samples were sieved to less than 2 millimeters and analyzed for 44 major and trace elements following a near-total multi-acid extraction. Soil pH was also determined. The geochemical data were compared to a background dataset consisting of 160 soil samples previously collected from the same depth throughout the State of Wyoming as part of another ongoing study by the U.S. Geological Survey. Risk from potentially toxic elements in soil from the site to biologic receptors and humans was estimated by comparing the concentration of these elements with soil screening values established by the U.S. Environmental Protection Agency. All 19 samples exceeded the carcinogenic human health screening level for arsenic in residential soils of 0.39 milligrams per kilogram (mg/kg), which represents a one-in-one-million cancer risk (median arsenic concentration in the study area is 2.7 mg/kg). All 19 samples also exceeded the lead and vanadium screening levels for birds. Eighteen of the 19 samples exceeded the manganese screening level for plants, 13 of the 19 samples exceeded the antimony screening level for mammals, and 10 of 19 samples exceeded the zinc screening level for birds. However, these exceedances are also found in soils at most locations in the Wyoming Statewide soil database, and elevated concentrations alone are not necessarily cause for alarm. Uranium and thorium, two other elements of environmental concern, are elevated in soils at the site as compared to the Wyoming dataset, but no human or ecological soil screening levels have been established for these elements.

  18. Characterization and remediation of soil prior to construction of an on-site disposal facility at Fernald

    SciTech Connect

    Hunt, A.; Jones, G.; Janke, R.; Nelson, K.

    1998-03-01

    During the production years at the Feed Materials Production Center (FMPC), the soil of the site and the surrounding areas was surficially impacted by airborne contamination. The volume of impacted soil is estimated at 2.2 million cubic yards. During site remediation, this contamination will be excavated, characterized, and disposed of. In 1986 the US Environmental Protection Agency (EPA) and the Department of Energy (DOE) entered into a Federal Facility Compliance Agreement (FFCA) covering environmental impacts associated with the FMPC. A site wide Remedial Investigation/Feasibility Study (RI/FS) was initiated pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act, as amended by the Superfund Amendments and Reauthorization Act (CERCLA). The DOE has completed the RI/FS process and has received approval of the final Records of Decision. The name of the facility was changed to the Fernald Environmental Management Project (FEMP) to emphasize the change in mission to environmental restoration. Remedial actions which address similar scopes of work or types of contaminated media have been grouped into remedial projects for the purpose of managing the remediation of the FEMP. The Soil Characterization and Excavation Project (SCEP) will address the remediation of FEMP soils, certain waste units, at- and below-grade material, and will certify attainment of the final remedial limits (FRLs) for the FEMP. The FEMP will be using an on-site facility for low level radioactive waste disposal. The facility will be an above-ground engineered structure constructed of geological material. The area designated for construction of the base of the on-site disposal facility (OSDF) is referred to as the footprint. Contaminated soil within the footprint must be identified and remediated. Excavation of Phase 1, the first of seven remediation areas, is complete.

  19. Quantification of the effects of spatially varying environmental contaminants into a cost model for soil remediation

    SciTech Connect

    Broos, M.J.; Stein, A.; Aarts, L.; Tooren, C.F. tan

    1999-06-01

    In this study the authors investigated the effects of spatial variability of soil contaminants on cost calculations for soil remediation. Most cost models only provide a single figure, whereas spatial variability is one of the sources to contribute to the uncertainty. A cost model is applied to a study site of 19 ha containing a former gasworks in the Rotterdam harbor. The site was contaminated by heavy metals, PAH and mineral oil. Two sets of environmental thresholds were applied, one for identifying the severeness of contamination and one to decide upon the future use of excavated soil. Three remediation scenarios were compared. Geostatistical simulations were applied, both on individual contaminants and on indicator variables derived from these. As it turns out, spatial uncertainty causes 2--5% uncertainty in the final cost estimates. Another source of uncertainty is the direction of application of the cost model: a least-case approach starts with the lowest threshold value, followed by increasingly higher values, whereas a worst-case approach starts with the highest threshold value followed by decreasing values. Using a worst-case approach yielded cost estimates that were 6--8% higher than cost estimates by a least-case approach. The authors concluded that 8--13% of the uncertainty in cost estimates could be explained by spatial variation of soil contaminants and lithology.

  20. From conceptual model to remediation: bioavailability, a key to clean up heavy metal contaminated soils.

    NASA Astrophysics Data System (ADS)

    Petruzzelli, Gianniantonio; Pedron, Francesca; Pezzarossa, Beatrice

    2013-04-01

    Processes of metal bioavailability in the soil To know the bioavailability processes at site specific levels is essential to understand in detail the risks associated with pollution, and to support the decision-making process, i.e. description of the conceptual model and choice of clean up technologies. It is particularly important to assess how chemical, physical and biological processes in the soil affect the reactions leading to adsorption, precipitation or release of contaminants. The measurement of bioavailability One of the main difficulties in the practical application of the bioavailability concept in soil remediation is the lack of consensus on the method to be used to measure bioavailability. The best strategy is to apply a series of tests to assess bioavailability, since no applicable method is universally valid under all conditions. As an example, bioavailability tests for phytotechnology application should consider two distinct aspects: a physico-chemical driven solubilization process and a physiologically driven uptake process. Soil and plant characteristics strongly influence bioavailability. Bioavailability as a tool in remediation strategies Bioavailability can be used at all stages in remediation strategies: development of the conceptual model, evaluation of risk assessment, and selection of the best technology, considering different scenarios and including different environmental objectives. Two different strategies can be followed: the reduction and the increase of bioavailability. Procedures that reduce bioavailability aim to prevent the movement of pollutants from the soil to the living organisms, essentially by: i) removal of the labile phase of the contaminant, i.e. the fraction which is intrinsic to the processes of bioavailability (phytostabilization); ii) conversion of the labile fraction into a stable fraction (precipitation or adsorption); iii) increase of the resistance to mass transfer of the contaminants (inertization). Procedures

  1. 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

  2. Geophysical Monitoring of Hydrocarbon-Contaminated Soils Remediated with a Bioelectrochemical System.

    PubMed

    Mao, Deqiang; Lu, Lu; Revil, André; Zuo, Yi; Hinton, John; Ren, Zhiyong Jason

    2016-08-01

    Efficient noninvasive techniques are desired for monitoring the remediation process of contaminated soils. We applied the direct current resistivity technique to image conductivity changes in sandbox experiments where two sandy and clayey soils were initially contaminated with diesel hydrocarbon. The experiments were conducted over a 230 day period. The removal of hydrocarbon was enhanced by a bioelectrochemical system (BES) and the electrical potentials of the BES reactors were also monitored during the course of the experiment. We found that the variation in electrical conductivity shown in the tomograms correlate well with diesel removal from the sandy soil, but this is not the case with the clayey soil. The clayey soil is characterized by a larger specific surface area and therefore a larger surface conductivity. In sandy soil, the removal of the diesel and products from degradation leads to an increase in electrical conductivity during the first 69 days. This is expected since diesel is electrically insulating. For both soils, the activity of BES reactors is moderately imaged by the inverted conductivity tomogram of the reactor. An increase in current production by electrochemically active bacteria activity corresponds to an increase in conductivity of the reactor. PMID:27386889

  3. 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

  4. [In situ immobilization remediation of heavy metals-contaminated soils: a review].

    PubMed

    Wang, Li-Qun; Luo, Lei; Ma, Yi-Bing; Wei, Dong-Pu; Hua, Luo

    2009-05-01

    In situ immobilization of heavy metals in contaminated soils by adding extraneous active amendments has been considered as a cost-effective measure for contaminated soil remediation. Application of immobilization amendments can decrease the available fractions of heavy metals or change their redox states, and thus, effectively decrease the mobility, bioavailability, and toxicity of the heavy metals in soils. This paper summarized the present researches about the in situ immobilization of heavy metals in soils, including kinds of immobilization amendments, research methods, immobilization indexes, immobilization mechanisms, and relevant environmental risk assessment. The mostly applied amendments include clay minerals, phosphates, organic composts, and microbes. Due to the complexity of soil matrix and the limitations of current analytical techniques, the exact immobilization mechanisms have not been clarified, which could include precipitation, chemical adsorption and ion exchange, surface precipitation, formation of stable complexes with organic ligands, and redox reaction. The prospects and limitations of in situ immobilization of heavy metals in soils were discussed. Future work should focus on the elucidation of immobilization mechanisms at molecular scale, with specific attention be paid to the potential risks of applying immobilization amendments and its long-term effects on field soils. PMID:19803184

  5. Remediation of arsenic in soil by Aspergillus nidulans isolated from an arsenic-contaminated site.

    PubMed

    Maheswari, S; Murugesan, A G

    2009-08-01

    High concentrations of heavy metals, such as arsenic, in soils have potential long-term environmental and health consequences due to their persistence in the environment and their associated toxicity to biological organisms. Aspergillus nidulans isolated from arsenic-contaminated soil has the potential to remove arsenic from soil. The isolated resistant strain showed resistance up to 500 ppm and the mean weight was found to be 1.309 g. The main objective of this research was to study the improvement to the remediation of arsenic-contaminated soil by the addition of nutrient sources such as carbon (0.15-0.85 g L(-1)), nitrogen (0.25-1.05 g L(-1)) and phosphate (0.10-0.30 g L(-1)) to the medium. The effect of ionic strength on Aspergillus nidulans was optimized by NaCl at 0.12-0.30%. The biomass concentration and growth profile of Aspergillus nidulans in arsenic-contaminated soil was found to be 0.709 g after 11 days. The arsenic adsorption potential of Aspergillus nidulans from the contaminated soil was found to be 84.35% after 11 days at pH 4 and a temperature of 35 degrees C. This investigation indicated that the isolated resistant strain had an important role in adsorption of arsenic from the contaminated soil. PMID:19803330

  6. Independent Verification Survey of the Clean Coral Storage Pile at the Johnston Atoll Plutonium-Contaminated Soil Remediation Project

    SciTech Connect

    Wilson-Nichols, M.J.

    2000-12-07

    The Oak Ridge National Laboratory (ORNL) Environmental Technology Section conducted an independent verification (IV) survey of the clean storage pile at the Johnston Atoll Plutonium Contaminated Soil Remediation Project (JAPCSRP) from January 18-25, 1999. The goal of the JAPCSRP is to restore a 24-acre area that was contaminated with plutonium oxide particles during nuclear testing in the 1960s. The selected remedy was a soil sorting operation that combined radiological measurements and mining processes to identify and sequester plutonium-contaminated soil. The soil sorter operated from about 1990 to 1998. The remaining clean soil is stored on-site for planned beneficial use on Johnston Island. The clean storage pile currently consists of approximately 120,000 m{sup 3} of coral. ORNL conducted the survey according to a Sampling and Analysis Plan, which proposed to provide an IV of the clean pile by collecting a minimum number (99) of samples. The goal was to ascertain with 95% confidence whether 97% of the processed soil is less than or equal to the accepted guideline (500-Bq/kg or 13.5-pCi/g) total transuranic (TRU) activity. In previous IV tasks, ORNL has (1) evaluated and tested the soil sorter system software and hardware and (2) evaluated the quality control (QC) program used at the soil sorter plant. The IV has found that the soil sorter decontamination was effective and significantly reduced plutonium contamination in the soil processed at the JA site. The Field Command Defense Threat Reduction Agency currently plans to re-use soil from the clean pile as a cover to remaining contamination in portions of the radiological control area. Therefore, ORNL was requested to provide an IV. The survey team collected samples from 103 random locations within the top 4 ft of the clean storage pile. The samples were analyzed in the on-site radioanalytical counting laboratory with an American Nuclear Systems (ANS) field instrument used for the detection of low

  7. Regeneration strategies of polymers employed in ex-situ remediation of contaminated soil: Bioregeneration versus solvent extraction.

    PubMed

    Mosca Angelucci, Domenica; Tomei, M Concetta

    2015-08-15

    In this study we evaluated the feasibility of two regeneration strategies of contaminated polymers employed for ex-situ soil remediation in a two-step process. Soil decontamination is achieved by sorption of the pollutants on the polymer beads, which are regenerated in a subsequent step. Tested soil was contaminated with a mixture of 4-chlorophenol and pentachlorophenol, and a commercial polymer, Hytrel, has been employed for extraction. Removal efficiencies of the polymer-soil extraction are in the range of 51-97% for a contact time ≤ 24 h. Two polymer regeneration strategies, solvent extraction and biological regeneration (realized in a two-phase partitioning bioreactor), were tested and compared. Performance was assessed in terms of removal rates and efficiencies and an economic analysis based on the operating costs has been performed. Results demonstrated the feasibility of both regeneration strategies, but the bioregeneration was advantageous in that provided the biodegradation of the contaminants desorbed from the polymer. Practically complete removal for 4-chlorophenol and up to 85% biodegradation efficiency for pentachlorophenol were achieved. Instead, in the solvent extraction, a relevant production (184-831 L kg(pol)(-1)) of a highly polluted stream to be treated or disposed of is observed. The cost analysis of the two strategies showed that the bioregeneration is much more convenient with operating costs of ∼12 €/kg(pol) i.e. more than one order of magnitude lower in comparison to ∼233 €/kg(pol) of the solvent extraction. PMID:26074469

  8. The Impacts of Thermal and Smouldering Remediation on Soil Properties Related to Rehabilitation and Plant Growth

    NASA Astrophysics Data System (ADS)

    Pape, A.; Knapp, C.; Switzer, C.

    2012-04-01

    Tens of thousands of sites worldwide are contaminated with toxic non-aqueous phase liquids (NAPLs) reducing their economic and environmental value. As a result a number of treatments involving heat and smouldering have been developed to desorb and extract or destroy these contaminants including; steam injection (<110°C), electrical heating (<110°C), microwave heating (ambient to 400°C),conductive heating (ambient to 800°C) and in-situ smouldering (800°C to 1200°C). Implemented correctly these treatments are efficient enough for the soil to be safe for use, but the heating may unintentionally reduce the capability of the soil to act as a growing media. To investigate the effects of elevated temperature soils samples were heated at fixed temperatures (ambient to 1000°C) for one hour or smouldered after artificial contamination. Temperatures up to 105°C resulted in very little change in soil properties but at 250°C nutrients became more available. At 500°C little organic matter or nitrogen remained in the soil and clay sized particles started to decompose and aggregate. By 1000°C total and available phosphorus were very low, cation exchange capacity had been reduced, pH had increased and the clay fraction had been completely lost. Similar changes were observed in smouldered soils with variations dependent upon remediation conditions. As a result the smouldered soils will require nutrient supplementation to facilitate plant growth. Nutrient addition will also improve the physical properties of the soil and serve to re-inoculate it with microbes, particularly if an organic source such as compost or sewage sludge is used. The soils may remain effective growing media during lower temperature treatments; however some sort of soil inoculant would also be beneficial as these temperatures are sufficient to sterilise the system, which may impact nutrient cycling. Further work involving months-long exposure to the elevated temperatures that are typical of thermal

  9. Hydraulic fracturing to enhance the remediation of DNAPL in low permeability soils

    SciTech Connect

    Murdoch, L.; Slack, B.

    1996-08-01

    Meager rates of fluid flow are a major obstacle to in situ remediation of low permeability soils. This paper describes methods designed to avoid that obstacle by creating fractures and filling them with sand to increase well discharge and change paths of fluid flow in soil. Gently dipping fractures 10 m in maximum dimension and 1 to 2 cm thick can be created in some contaminated soils at depths of a few in or greater. Hydraulic fractures can also be used to create electrically conductive layers or to deliver granules of chemically or biologically active compounds that will degrade contaminants in place. Benefits of applying hydraulic fractures to DNAPL recovery include rates of fluid recovery, enhancing upward gradients to improve hydrodynamic stabilization, forming flat-lying reactive curtains to intersect compounds moving downward, or improving the performance of electrokinetics intended to recover compounds dissolved in water. 30 refs., 7 figs., 1 tab.

  10. Remediation of copper contaminated soil by using different particle sizes of apatite: a field experiment.

    PubMed

    Xing, Jinfeng; Hu, Tiantian; Cang, Long; Zhou, Dongmei

    2016-01-01

    The particle size of apatite is one of the critical factors that influence the adsorption of heavy metals on apatite in the remediation of heavy metal contaminated soils using apatite. However, little research has been done evaluating the impact of different particle sizes of apatite on immobilization remediation of heavy metal polluted soils in field. In this study, the adsorption isothermal experiments of copper on three kinds of apatite was tested, and the field experiment by using different particle sizes apatite [nano-hydroxyapatite (NAP), micro-hydroxyapatite (MAP), ordinary particle apatite (OAP)] at a same dosage of 25.8 t/ha (1.16 %, W/W) was also conducted. Ryegrass was chosen as the test plant. The ryegrass biomass, the copper contents in ryegrass and the copper fractionations in soil were determined after field experiments. Results of adsorption experiments showed that the adsorption amounts of copper on OAP was the lowest among different particles. The adsorption amounts of copper on MAP was higher than NAP at high copper equilibrium concentration (>1 mmol L(-1)), an opposite trend was obtained at low copper concentration (<1 mmol L(-1)). In the field experiment, we found that the application of different apatites could effectively increase the soil pH, decrease the available copper concentration in soil, provide more nutrient phosphate and promote the growth of ryegrass. The ryegrass biomass and the copper accumulation in ryegrass were the highest in MAP among all treatments. The effective order of apatite in phytoremediation of copper contaminated field soil was MAP > NAP > OAP, which was attributed to the high adsorption capacity of copper and the strong releasing of phosphate by MAP. PMID:27512641

  11. Remediation of Pb/Cr co-contaminated soil using electrokinetic process and approaching electrode technique.

    PubMed

    Ng, Yee-Sern; Sen Gupta, Bhaskar; Hashim, Mohd Ali

    2016-01-01

    Electrokinetic process has emerged as an important tool for remediating heavy metal-contaminated soil. The process can concentrate heavy metals into smaller soil volume even in the absence of hydraulic flow. This makes it an attractive soil pre-treatment method before other remediation techniques are applied such that the chemical consumption in the latter stage can be reduced. The present study evaluates the feasibility of electrokinetic process in concentrating lead (Pb) and chromium (Cr) in a co-contaminated soil using different types of wetting agents, namely 0.01 M NaNO3, 0.1 M citric acid and 0.1 M EDTA. The data obtained showed that NaNO3 and citric acid resulted in poor Pb electromigration in this study. As for Cr migration, these agents were also found to give lower electromigration rate especially at low pH region as a result of Cr(VI) adsorption and possible reduction into Cr(III). In contrast, EDTA emerged as the best wetting agent in this study as it formed water-soluble anionic complexes with both Pb and Cr. This provided effective one-way electromigration towards the anode for both ions, and they were accumulated into smaller soil volume with an enrichment ratio of 1.55-1.82. A further study on the application of approaching cathode in EDTA test showed that soil alkalisation was achieved, but this did not provide significant enhancement on electromigration for Pb and Cr. Nevertheless, the power consumption for electrokinetic process was decreased by 22.5%. PMID:26330317

  12. Electrokinetic delivery of persulfate to remediate PCBs polluted soils: effect of injection spot.

    PubMed

    Fan, Guangping; Cang, Long; Fang, Guodong; Qin, Wenxiu; Ge, Liqiang; Zhou, Dongmei

    2014-12-01

    Persulfate-based in situ chemical oxidation (ISCO) is a promising technique for the remediation of organic compounds contaminated soils. Electrokinetics (EK) provides an alternative method to deliver oxidants into the target zones especially in low permeable-soil. In this study, the flexibility of delivering persulfate by EK to remediate polychlorinated biphenyls (PCBs) polluted soil was investigated. 20% (w/w) of persulfate was injected at the anode, cathode and both electrodes to examine its transport behaviors under electrical field, and the effect of field inversion process was also evaluated. The results showed that high dosage of persulfate could be delivered into S4 section (near cathode) by electroosmosis when persulfate was injected from anode, 30.8% of PCBs was removed from the soil, and the formed hydroxyl precipitation near the cathode during EK process impeded the transportation of persulfate. In contrast, only 18.9% of PCBs was removed with the injection of persulfate from cathode, although the breakthrough of persulfate into the anode reservoir was observed. These results indicated that the electroosmotic flow is more effective for the transportation of persulfate into soil. The addition of persulfate from both electrodes did not significantly facilitate the PCBs oxidation as well as the treatment of electrical field reversion, the reinforced negative depolarization function occurring in the cathode at high current consumed most of the oxidant. Furthermore, it was found that strong acid condition near the anode favored the oxidation of PCBs by persulfate and the degradation of PCBs was in consistent with the oxidation of Soil TOC in EK/persulfate system. PMID:25193794

  13. USEPA'S RESEARCH PROGRAM ON REMEDIATION AND CONTAINMENT OF ARSENIC AND MERCURY IN SOILS, INDUSTRIAL WASTES, AND GROUNDWATER

    EPA Science Inventory

    In the U.S. and around the world, mercury and arsenic contaminated soils, industrial wastes, and groundwater are difficult to effectively and cheaply remediate and contain. Mercury is a serious health concern and has been identified as a contaminant in the air, soil, sediment, su...

  14. USE OF PLANT AND EARTHWORM BIOASSYS TO EVALUATE REMEDIATION OF SOIL FROM A SITE CONTAMINATED WITH POLYCHLORINATED BIPHENYLS

    EPA Science Inventory

    Soil from a site heavily contaminated with polychlorinated biphenyls (PCBs) was treated with a pilot-scale, solvent extraction tehnology. Bioassays in earthworms and plants were used to examine the efficacy of the remediation process for reducing the toxicity of the soil. The ear...

  15. USE OF PLANT AND EARTHWORM BIOASSAYS TO EVALUATE REMEDIATION OF SOIL FROM A SITE CONTAMINATED WITH POLYCHLORINATED BIPHENYLS

    EPA Science Inventory

    Soil from a site heavily contaminated with polychlorinated biphenyls (PCBs) was treated with a pilot-scale, solvent extraction technology. Bioassays in earthworms and plants were used to examine the efficacy of the remediation process for reducing the toxicity of the soil. The ...

  16. Assessment of three remediation strategies for reduction of Shiga-toxigenic Escherichia coli (STEC) O157 in naturally contaminated soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Justification: Cattle are a known reservoir of the foodborne pathogen STEC O157. After being shed from the animal, the contaminated feces become incorporated in the soil. Objective: To evaluate three potential strategies for remediation of STEC O157 from naturally contaminated soils. Methods: T...

  17. Caresoil: A multidisciplinar Project to characterize, remediate, monitor and evaluate the risk of contaminated soils in Madrid (Spain)

    NASA Astrophysics Data System (ADS)

    Muñoz-Martín, Alfonso; Antón, Loreto; Granja, Jose Luis; Villarroya, Fermín; Montero, Esperanza; Rodríguez, Vanesa

    2016-04-01

    Soil contamination can come from diffuse sources (air deposition, agriculture, etc.) or local sources, these last being related to anthropogenic activities that are potentially soil contaminating activities. According to data from the EU, in Spain, and particularly for the Autonomous Community of Madrid, it can be considered that heavy metals, toxic organic compounds (including Non Aqueous Phases Liquids, NAPLs) and combinations of both are the main problem of point sources of soil contamination in our community. The five aspects that will be applied in Caresoil Program (S2013/MAE-2739) in the analysis and remediation of a local soil contamination are: 1) the location of the source of contamination and characterization of soil and aquifer concerned, 2) evaluation of the dispersion of the plume, 3) application of effective remediation techniques, 4) monitoring the evolution of the contaminated soil and 5) risk analysis throughout this process. These aspects involve advanced technologies (hydrogeology, geophysics, geochemistry,...) that require new developing of knowledge, being necessary the contribution of several researching groups specialized in the fields previously cited, as they are those integrating CARESOIL Program. Actually two cases concerning hydrocarbon spills, as representative examples of soil local contamination in Madrid area, are being studied. The first is being remediated and we are monitoring this process to evaluate its effectiveness. In the second location we are defining the extent of contamination in soil and aquifer to define the most effective remediation technique.

  18. Treatability study report for remediation of chemical warfare agent contaminated soils using peroxysulfate ex-situ treatment. Final report

    SciTech Connect

    Pugh, J.R.; Grinstead, J.H.; Farley, J.A.; Enlow, P.D.; Kelly, D.A.

    1996-07-01

    This laboratory scale study examines the feasibility of using peroxysulfate based oxidants to remediate soils contaminated with GB, Hi, and VX. The project was conducted with chemical warfare agent simulants. The study concludes that peroxysulfates, and particularly peroxydisulfate, can degrade chemical warfare agent simulants in soil and recommends continuing research.

  19. Combined remediation of Cd-phenanthrene co-contaminated soil by Pleurotus cornucopiae and Bacillus thuringiensis FQ1 and the antioxidant responses in Pleurotus cornucopiae.

    PubMed

    Jiang, Juan; Liu, Hongying; Li, Qiao; Gao, Ni; Yao, Yuan; Xu, Heng

    2015-10-01

    Remediation of soil co-contaminated with heavy metals and PAHs by mushroom and bacteria is a novel technique. In this study, the combined remediation effect of mushroom (Pleurotus cornucopiae) and bacteria (FQ1, Bacillus thuringiensis) on Cd and phenanthrene co-contaminated soil was investigated. The effect of bacteria (B. thuringiensis) on mushroom growth, Cd accumulation, phenanthrene degradation by P. cornucopiae and antioxidative responses of P. cornucopiae were studied. P. cornucopiae could adapt easily and grow well in Cd-phenanthrene co-contaminated soil. It was found that inoculation of FQ1 enhanced mushroom growth (biomass) and Cd accumulation with the increment of 26.68-43.58% and 14.29-97.67% respectively. Up to 100% and 95.07% of phenanthrene were removed in the bacteria-mushroom (B+M) treatment respectively spiked with 200mg/kg and 500mg/kg phenanthrene. In addition, bacterial inoculation alleviated oxidative stress caused by co-contamination with relative decreases in lipid peroxidation and enzyme activity, including malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). This study demonstrated that the integrated remediation strategy of bacteria and mushroom is an effective and promising method for Cd-phenanthrene co-contaminated soil bioremediation. PMID:26117363

  20. Integrated phytobial remediation for sustainable management of arsenic in soil and water.

    PubMed

    Roy, Madhumita; Giri, Ashok K; Dutta, Sourav; Mukherjee, Pritam

    2015-02-01

    Arsenic (As), cited as the most hazardous substance by the U.S. Agency for Toxic Substance and Disease Registry (ATSDR, 2005), is an ubiquitous metalloid which when ingested for prolonged periods cause extensive health effects leading to ultimate untimely death. Plants and microbes can help mitigate soil and groundwater As problem since they have evolved elaborate detoxification machineries against this toxic metalloid as a result of their coexistence with this since the origin of life on earth. Utilization of the phytoremediation and bioremediation potential of the plants and microbes, respectively, is now regarded as two innovative tools that encompass biology, geology, biotechnology and allied sciences with cutting edge applications for sustainable mitigation of As epidemic. Discovery of As hyperaccumulating plants that uptake and concentrate large amounts of this toxic metalloid in their shoots or roots offered new hope to As phytoremediation, solar power based nature's own green remediation. This review focuses on how phytoremediation and bioremediation can be merged together to form an integrated phytobial remediation which could synergistically achieve the goal of large scale removal of As from soil, sediment and groundwater and overcome the drawbacks of the either processes alone. The review also points to the feasibility of the introduction of transgenic plants and microbes that bring new hope for more efficient treatment of As. The review identifies one critical research gap on the importance of remediation of As contaminated groundwater not only for drinking purpose but also for irrigation purpose and stresses that more research should be conducted on the use of constructed wetland, one of the most suitable areas of application of phytobial remediation. Finally the review has narrowed down on different phytoinvestigation and phytodisposal methods, which constitute the most essential and the most difficult part of pilot scale and field scale applications

  1. Use of Tunable Whole-Cell Bioreporters to Assess Bioavailable Cadmium and Remediation Performance in Soils

    PubMed Central

    Yoon, Youngdae; Kim, Sunghoon; Chae, Yooeun; Kang, Yerin; Lee, Youngshim; Jeong, Seung-Woo; An, Youn-Joo

    2016-01-01

    It is important to have tools to measure the bioavailability to assess the risks of pollutants because the bioavailability is defined as the portions of pollutants showing the biological effects on living organisms. This study described the construction of tunable Escherichia coli whole-cell bioreporter (WCB) using the promoter region of zinc-inducible operon and its application on contaminated soils. It was verified that this WCB system showed specific and sensitive responses to cadmium rather than zinc in the experimental conditions. It was inferred that Cd(II) associates stronger with ZntR, a regulatory protein of zinc-inducible operon, than other metal ions. Moreover, the expression of reporter genes, egfp and mcherry, were proportional to the concentration of cadmium, thereby being a quantitative sensor to monitor bioavailable cadmium. The capability to determine bioavailable cadmium was verified with Cd(II) amended LUFA soils, and then the applicability on environmental systems was investigated with field soils collected from smelter area in Korea before and after soil-washing. The total amount of cadmium was decreased after soil washing, while the bioavailability was increased. Consequently, it would be valuable to have tools to assess bioavailability and the effectiveness of soil remediation should be evaluated in the aspect of bioavailability as well as removal efficiency. PMID:27171374

  2. Rhizobia and their bio-partners as novel drivers for functional remediation in contaminated soils

    PubMed Central

    Teng, Ying; Wang, Xiaomi; Li, Lina; Li, Zhengao; Luo, Yongming

    2015-01-01

    Environmental pollutants have received considerable attention due to their serious effects on human health. There are physical, chemical, and biological means to remediate pollution; among them, bioremediation has become increasingly popular. The nitrogen-fixing rhizobia are widely distributed in the soil and root ecosystems and can increase legume growth and production by supplying nitrogen, resulting in the reduced need for fertilizer applications. Rhizobia also possess the biochemical and ecological capacity to degrade organic pollutants and are resistant to heavy metals, making them useful for rehabilitating contaminated soils. Moreover, rhizobia stimulate the survival and action of other biodegrading bacteria, thereby lowering the concentration of pollutants. The synergistic action of multiple rhizobial strains enhances both plant growth and the availability of pollutants ranging from heavy metals to persistent organic pollutants. Because phytoremediation has some restrictions, the beneficial interaction between plants and rhizobia provides a promising option for remediation. This review describes recent advances in the exploitation of rhizobia for the rehabilitation of contaminated soil and the biochemical and molecular mechanisms involved, thereby promoting further development of this novel bioremediation strategy into a widely accepted technique. PMID:25699064

  3. Hybrid life cycle assessment comparison of colloidal silica and cement grouted soil barrier remediation technologies.

    PubMed

    Gallagher, Patricia M; Spatari, Sabrina; Cucura, Jeffrey

    2013-04-15

    Site remediation involves balancing numerous costs and benefits but often neglects the environmental impacts over the entire project life cycle. Life cycle assessment (LCA) offers a framework for inclusion of global environmental "systems-level" decision metrics in combination with technological and cost analysis. We compare colloidal silica (CS) and cement grouted soil barrier remediation technologies for soils affected by low level radionuclides at a U.S. Superfund site using hybrid LCA methods. CS is a new, high performance grouting material installed using permeation grouting techniques. Cement, a more traditional grouting material, is typically installed using jet grouting techniques. Life cycle impacts were evaluated using the US EPA TRACI 2 model. Results show the highest life cycle environmental impacts for the CS barrier occur during materials production and transportation to the site. In general, the life cycle impacts for the cement barrier were dominated by materials production; however, in the extreme scenario the life cycle impacts were dominated by truck transportation of spoils to a distant, off-site radioactive waste facility. It is only in the extreme scenario tested in which soils are transported by truck (Option 2) that spoils waste transport dominates LCIA results. Life cycle environmental impacts for both grout barriers were most sensitive to resource input requirements for manufacturing volumes and transportation. Uncertainty associated with the efficacy of new technology such as CS over its required design life indicates that barrier replacement could increase its life cycle environmental impact above that of the cement barrier. PMID:23500422

  4. Secondary successions of biota in oil-polluted peat soil upon different biological remediation methods

    NASA Astrophysics Data System (ADS)

    Melekhina, E. N.; Markarova, M. Yu.; Shchemelinina, T. N.; Anchugova, E. M.; Kanev, V. A.

    2015-06-01

    The effects of different bioremediation methods on restoration of the oil-polluted peat soil (Histosol) in the northernmost taiga subzone of European Russia was studied. The population dynamics of microorganisms belonging to different trophic groups (hydrocarbon-oxidizing, ammonifying, nitrifying, and oligonitrophilic) were analyzed together with data on the soil enzyme (catalase and dehydrogenase) activities, population densities of soil microfauna groups, their structures, and states of phytocenoses during a sevenyear-long succession. The remediation with biopreparations Roder composed of oil-oxidizing microorganisms-Roder with Rhodococcus rubber and R. erythropolis and Universal with Rhodotorula glutinis and Rhodococcus sp.-was more efficient than the agrochemical and technical remediation. It was concluded that the biopreparations activate microbiological oil destruction, thereby accelerating restoration succession of phytocenosis and zoocenosis. The succession of dominant microfauna groups was observed: the dipteran larvae and Mesostigmata mites predominant at the early stages were replaced by collembolans at later stages. The pioneer oribatid mite species were Tectocepheus velatus, Oppiella nova, Liochthonius sellnicki, Oribatula tibialis, and Eupelops sp.

  5. [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. PMID:26164925

  6. Remediation of soil co-contaminated with petroleum and heavy metals by the integration of electrokinetics and biostimulation.

    PubMed

    Dong, Zhi-Yong; Huang, Wen-Hui; Xing, Ding-Feng; Zhang, Hong-Feng

    2013-09-15

    Successful remediation of soil co-contaminated with high levels of organics and heavy metals is a challenging task, because that metal pollutants in soil can partially or completely suppress normal heterotrophic microbial activity and thus hamper biodegradation of organics. In this study, the benefits of integrating electrokinetic (EK) remediation with biodegradation for decontaminating soil co-contaminated with crude oil and Pb were evaluated in laboratory-scale experiments lasting for 30 days. The treated soil contained 12,500 mg/kg of total petroleum hydrocarbons (TPH) and 450 mg/kg Pb. The amendments of EDTA and Tween 80, together with a regular refreshing of electrolyte showed the best performance to remediate this contaminated soil. An important function of EDTA-enhanced EK treatment was to eliminate heavy metal toxicity from the soil, thus activating microbial degradation of oil. Although Tween 80 reduced current, it could serve as a second substrate for enhancing microbial growth and biodegradation. It was found that oil biodegradation degree and microbial numbers increased toward the anode and cathode. Microbial metabolism was found to be beneficial to metal release from the soil matrix. Under the optimum conditions, the soil Pb and TPH removal percentages after 30 days of running reached 81.7% and 88.3%, respectively. After treatment, both the residual soil Pb and TPH concentrations met the requirement of the Chinese soil environmental quality standards. PMID:23807474

  7. CHARACTERIZATION OF CONDITIONS OF NATURAL GAS STORAGE RESERVOIRS AND DESIGN AND DEMONSTRATION OF REMEDIAL TECHNIQUES FOR DAMAGE MECHANISMS FOUND THEREIN

    SciTech Connect

    J.H. Frantz; K.E. Brown

    2003-02-01

    There are four primary goals of contract DE-FG26-99FT40703: (1) We seek to better understand how and why two damage mechanisms--(1) inorganic precipitants, and (2) hydrocarbons and organic residues, occur at the reservoir/wellbore interface in gas storage wells. (2) We plan on testing potential prevention and remediation strategies related to these two damage mechanisms in the laboratory. (3) We expect to demonstrate in the field, cost-effective prevention and remediation strategies that laboratory testing deems viable. (4) We will investigate new technology for the gas storage industry that will provide operators with a cost effective method to reduce non-darcy turbulent flow effects on flow rate. For the above damage mechanisms, our research efforts will demonstrate the diagnostic technique for determining the damage mechanisms associated with lost deliverability as well as demonstrate and evaluate the remedial techniques in the laboratory setting and in actual gas storage reservoirs. We plan on accomplishing the above goals by performing extensive lab analyses of rotary sidewall cores taken from at least two wells, testing potential remediation strategies in the lab, and demonstrating in the field the applicability of the proposed remediation treatments. The benefits from this work will be quantified from this study and extrapolated to the entire storage industry. The technology and project results will be transferred to the industry through DOE dissemination and through the industry service companies that work on gas storage wells. Achieving these goals will enable the underground gas storage industry to more cost-effectively mitigate declining deliverability in their storage fields. Work completed to date includes the following: (1) Solicited potential participants from the gas storage industry; (2) Selected one participant experiencing damage from inorganic precipitates; (3) Developed laboratory testing procedures; (4) Collected cores from National Fuel Gas

  8. MICHIGAN SOIL VAPOR EXTRACTION REMEDIATION (MISER) MODEL: A COMPUTER PROGRAM TO MODEL SOIL VAPOR EXTRACTION AND BIOVENTING OF ORGANIC CHEMICALS IN UNSATURATED GEOLOGICAL MATERIAL

    EPA Science Inventory

    Soil vapor extraction (SVE) and bioventing (BV) are proven strategies for remediation of unsaturated zone soils. Mathematical models are powerful tools that can be used to integrate and quantify the interaction of physical, chemical, and biological processes occurring in field sc...

  9. Human and ecological remediation goals for soil mercury at East Fork Poplar Creek, Oak Ridge, TN

    SciTech Connect

    Zafran, F.A.; Cornaby, B.W.; Hadden, C.T. |

    1995-12-31

    Mercury, used in the past production of enriched lithium by the Department of Energy, is the principal chemical of concern in the 14-mile floodplain of East Fork Poplar Creek (EFPC). SAIC has developed risk-based remediation goal options (RGOS) for mercury in EFPC soils to protect the most sensitive human receptors. The existing chronic oral RfD for mercury is based on exposure of laboratory species to mercuric chloride. However, speciation and leaching/availability studies (conducted by EPA EMSL and Oak Ridge National Laboratory) indicated less soluble and less toxic mercury species, principally mercuric sulfide, with measurable quantities of metallic mercury also present, predominate in EFPC floodplain soils. SAIC derived human health RGOs using deterministic and probabilistic methods and incorporated the probability density function for bioavailability of mercury species from leaching/availability data generated by ORNL. Monte Carlo simulation was used in uncertainty analysis and supported the derivation of a protective, but realistic risk-based remediation goal of 400 mg mercury/kg soil. For ecological risk assessment, RGOs were based on risks through food chains from contaminants in soil. The authors describe a terrestrial food-chain model of contaminant transfer to primary producers, first-order consumers, mid-level predators, and top-level predators. The model uses published toxicity data, site-specific contaminant concentrations, and bioaccumulation factors calculated from measured body burdens of floodplain organisms to compute RGOs for various combinations of exposure parameters. Model calculations show that under reasonably conservative conditions, mid-level predators have the highest exposures relative to dietary limits and, therefore, require the lowest soil-mercury RGOs. Mercury concentrations of {approximately}500 mg/kg are protective of the receptor populations exposed through food chains at this site.

  10. RECARE - Preventing and Remediating Degradation of Soils in Europe through Landcare.

    NASA Astrophysics Data System (ADS)

    van den Elsen, Erik; Hessel, Rudi; Verzandvoort, Simone; Ritsema, Coen; Geissen, Violette

    2015-04-01

    Although there is a large body of knowledge available on soil threats in Europe, this knowledge is fragmented and incomplete, in particular regarding the complexity and functioning of soil systems and their interaction with human activities. The main aim of the RECARE project is to develop effective prevention, remediation and restoration measures using an innovative trans-disciplinary approach, actively integrating and advancing knowledge of stakeholders and scientists in 17 Case Studies, covering a range of soil threats in different bio-physical and socio-economic environments across Europe. Within these Case Study sites, i) the current state of degradation and conservation will be assessed using a new methodology, based on the WOCAT mapping procedure, ii) impacts of degradation and conservation on soil functions and ecosystem services will be quantified in a harmonized, spatially explicit way, accounting for costs and benefits, and possible trade-offs, iii) prevention, remediation and restoration measures selected and implemented by stakeholders in a participatory process will be evaluated regarding efficacy, and iv) the applicability and impact of these measures at the European level will be assessed using a new integrated bio-physical and socio-economic model, accounting for land use dynamics as a result of for instance economic development and policies. Existing national and EU policies will be reviewed and compared to identify potential incoherence, contradictions and synergies. Policy messages will be formulated based on the Case Study results and their integration at European level. A comprehensive dissemination and communication strategy, including the development of a web-based Dissemination and Communication Hub, will accompany the other activities to ensure that project results are disseminated to a variety of stakeholders at the right time and in the appropriate formats to stimulate renewed care for European soils.

  11. In situ remediation and phytotoxicity assessment of lead-contaminated soil by biochar-supported nHAP.

    PubMed

    Yang, Zhangmei; Fang, Zhanqiang; Tsang, Pokeung Eric; Fang, Jianzhang; Zhao, Dongye

    2016-11-01

    In this study, a kind of biochar-supported nano-hydroxyapatite (nHAP@BC) material was used in in-situ remediation of lead-contaminated soil. Column experiments were performed to compare the mobility of nHAP@BC and Bare-nHAP. The immobilization, accumulation and toxic effects of Pb in the after-amended soil were assessed by the in vitro toxicity tests and pot experiments. The column experiments showed a significant improvement in the mobility of nHAP@BC. The immobilization rate of Pb in the soil was 74.8% after nHAP@BC remediation. Sequential extraction procedures revealed that the residual fraction of Pb increased by 66.6% after nHAP@BC remediation, which greatly reduced the bioavailability of Pb in the soil. In addition, pot experiments indicated that nHAP@BC could effectively reduce the upward translocation capacity of Pb in a soil-plant system. The concentration of Pb in the aerial part of the cabbage mustard was 0.1 mg/kg, which is lower than the tolerance limit (0.3 mg/kg). nHAP@BC can remediate Pb-contaminated soil effectively, which can restore soil quality for planting. PMID:27479241

  12. 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

  13. Effects of Remediation Measures On Soil Available Phosphorus and Induced Phoshorus Losses

    NASA Astrophysics Data System (ADS)

    Schaerer, M.; Vollmer, T.; Sinaj, S.; Stamm, C.; Fluehler, H.; Frossard, E.

    Permanent grassland soils in areas with high livestock density are especially critical, since large phosphorus (P)-surpluses have accumulated in the topsoil due to high fertilizer and manure application rates. In Switzerland, programs are planned to reduce diffuse P-losses from agricultural land to surface waters. However, the efficiency and practicability of the proposed measures are mainly hypothetical. Therefore, we have established two field trials on grassland soils with the goal to study at the plot scale the effect of three "remediation measures" on soil P availability and induced P-losses. The total P contents in the 0- to 2-cm depth of both sites were high, 1.4 and 1.9 g P kg-1 soil respectively at site I and site II and decreased strongly in the lower parts of the both soil profiles. The concentrations of isotopically exchangeable P within 1 minute (E1min, readily available P) for the same depth were also very high, 58 and 27 mg P kg soil for the site I and II, respectively. These values decrease rapidly with depth. The experimental measures under study include (i) a control with normal P- input, (ii) zero P-input, (iii) a single tillage operation with zero P-input and (iv) zero P-input + a single tillage operation + addition of Fe-oxide (Fe-(II)-sulfate solution applied on the top of a soil/ calciumhydroxide mixture). The monitoring of P-losses includes sprinkling experiments inducing surface runoff, as well as runoff measurements under natural rainfall conditions. The remediation measures were applied in three or four replicates at both sites in early summer 2001. In the year 2000, the "status quo" of P-losses from the studied plots was also evaluated. Results from the first monitoring year (2000) indicated that both sites were potential source areas for the eutrophication of surface waters with respect to P-mobilization by runoff water. Sprinkling with deionized water caused runoff containing 0.8 and 0.9 mg total P L-1 at the site I and II

  14. Clay slurry and engineered soils as containment technologies for remediation of contaminated sites

    SciTech Connect

    Williams, J.R.; Dudka, S.; Miller, W.P.; Johnson, D.O.

    1997-12-31

    Clay Slurry and Engineered Soils are containment technologies for remediation of waste disposal sites where leaching, groundwater plumes and surface runoff of contaminants are serious ecological hazards to adjacent environments. This technology is a patent-pending process which involves the use of conditioned clay materials mixed with sand and water to form a readily pourable suspension, a clay slurry, which is either placed into a trench barrier system or allowed to de-water to create Engineered Soils. The Engineered Soil forms a layer impervious to water and air, therefore by inhibiting both water and oxygen from penetrating through the soil the material. This material can be installed in layers and as a vertical barrier to create a surface barrier containment system. The clay percentage in the clay slurry and Engineered Soils varies depending on site characteristics and desired performance standards. For example Engineered Soils with 1-2% of clay (dry wt.) had a hydraulic conductivity (K) of 10{sup -8} to 10{sup -1} cm/sec. Tests of tailing materials from a kyanite and pyrite mine showed that the clay slurry was effective not only in reducing the permeability of the treated tailings, but also in decreasing their acidity due to the inherent alkalinity of the clay. The untreated tailings had pH values in the range of 2.4 - 3.1; whereas, the effluent from clay and tailings mixtures had pH values in a slightly alkaline range (7.7-7.9). Pug-mills and high volume slurry pumps can be readily adapted for use in constructing and placing caps and creating Engineered Soils. Moreover, material on site or from a local sand supply can be used to create clay slurries and engineered soils. Clay materials used in cap construction are likewise readily available commercially. As a result, the clay slurry system is very cost effective compared to other capping systems, including the commonly used High Density Polyethylene (HDPE) liner systems.

  15. Surfactant-facilitated remediation of metal-contaminated soils: efficacy and toxicological consequences to earthworms.

    PubMed

    Slizovskiy, Ilya B; Kelsey, Jason W; Hatzinger, Paul B

    2011-01-01

    The effectiveness of surfactant formulations to remove aged metals from a field soil and their influence on soil toxicity was investigated. Batch studies were conducted to evaluate the efficacy of cationic (1-dodecylpyridinium chloride; DPC), nonionic (oleyl dimethyl benzyl ammonium chloride; trade name Ammonyx KP), and anionic (rhamnolipid biosurfactant blend; trade name JBR-425) surfactants for extracting Zn, Cu, Pb, and Cd from a soil subjected to more than 80 years of metal deposition. All three surfactants enhanced removal of the target metals. The anionic biosurfactant JBR-425 was most effective, reducing Zn, Cu, Pb, and Cd in the soil by 39, 56, 68, and 43%, respectively, compared with less than 6% removal by water alone. Progressive acidification of the surfactants with citric acid buffer or addition of ethylenediaminetetra-acetic acid (EDTA) further improved extraction efficiency, with more than 95% extraction of all four metals by surfactants acidified to pH 3.6 and generally greater than 90% removal of all metals with addition of 0.1 M EDTA. In two species of earthworm, Eisenia fetida and Lumbricus terrestris, metal bioaccumulation was reduced by approximately 30 to 80%, total biomass was enhanced by approximately threefold to sixfold, and survival was increased to greater than 75% in surfactant-remediated soil compared with untreated soil. The data indicate that surfactant washing may be a feasible approach to treat surface soils contaminated with a variety of metals, even if those metals have been present for nearly a century, and that the toxicity and potential for metal accumulation in biota from the treated soils may be significantly reduced. PMID:20853447

  16. Evaluation of a remediation process for lead contaminated soil by toxicity bioassays: Plants and earthworms

    SciTech Connect

    Chana, L.W.; Smith, K.

    1995-12-31

    Soil from a site contaminated with heavy metals (predominantly lead) was treated using the TERRAMET{reg_sign} lead extraction process. Earthworm acute toxicity and plant seed germination/root elongation (SG/RE) bioassays were used to evaluate the toxicity of the soil before treatment (BT), after treatment (AT) and after treatment, followed by rinsing with water, intended to simulate exposure to rainfall (RT). The results showed BT and RT were not toxic to earthworms in a 14-day exposure while AT showed significant toxicity. The LC{sub 50} values for Eisenia and Lumbricus were 44.04 and 28.83 (as % AT soil/test soil mixture), respectively. The phytotoxicity data indicated that all 3 test soils significantly inhibited lettuce SG/RE in a dose-related manner, with AT being the most phytotoxic. In oats, RT had no effect on SG/RE and AT was more toxic than BT. For the two local-site grass seeds tested (blue grama and sideoat grama), the AT soil was the most phytotoxic followed by BT and RT. The results suggest that the soil after this remediation process exerts significant toxicity on both plant and earthworm, but after a rain-simulating rinse, the toxicity is the same as, or less than, the toxicity before treatment. Further studies are in progress to confirm the assumption that the high salt concentrations generated by acidification during the leaching process, followed by neutralization are responsible for the increased toxicity of unrinsed soil in both plant and earthworm.

  17. Investigating biochar as a tool for environmental remediation

    EPA Science Inventory

    Biochar is being proposed as a cost-effective, carbon negative soil amendment for environmental remediation. Research has demonstrated the efficacy of biochar to sorb heavy metals and agricultural chemicals from contaminated soils, thus effectively reducing the potential for met...

  18. Efficiency of soil organic and inorganic amendments on the remediation of a contaminated mine soil: I. Effects on trace elements and nutrients solubility and leaching risk.

    PubMed

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

    2014-07-01

    A mesocosm experiment, in columns, was conducted in a growth chamber to assess the viability of two organic materials (pig slurry and compost; in combination with hydrated lime) for the remediation of a highly acidic and trace elements (TEs) contaminated mine soil and the reduction of its associated leaching risks. Their influence on the evolution throughout the soil depth of the physicochemical properties (including TEs mobility) of the soil and soil solution (in situ periodic collection) and on Lolium perenne growth and foliar TEs accumulation was evaluated. Soluble and extractable concentrations of the different TEs were considerably high, although the organic amendments (with lime) and lime addition successfully decreased TEs mobility in the top soil layer, as a consequence of a rise in pH and changes in the redox conditions. Compost and pig slurry increased the soluble organic-C and dissolved N, K and P of the soil, producing a certain downwards displacement of N and K. The organic amendments allowed the growth of L. perenne in the soil, thus indicating improvement of soil conditions, but elevated TEs availability in the soil led to toxicity symptoms and abnormally high TEs concentrations in the plants. An evaluation of the functioning and ecotoxicological risks of the remediated soils is reported in part II: this allows verification of the viability of the amendments for remediation strategies. PMID:24875879

  19. Remediation of heavy metal-contaminated forest soil using recycled organic matter and native woody plants.

    PubMed

    Helmisaari, H-S; Salemaa, M; Derome, J; Kiikkilä, O; Uhlig, C; Nieminen, T M

    2007-01-01

    The main aim of this study was to determine how the application of a mulch cover (a mixture of household biocompost and woodchips) onto heavy metal-polluted forest soil affects (i) long-term survival and growth of planted dwarf shrubs and tree seedlings and (ii) natural revegetation. Native woody plants (Pinus sylvestris, Betula pubescens, Empetrum nigrum, and Arctostaphylos uva-ursi) were planted in mulch pockets on mulch-covered and uncovered plots in summer 1996 in a highly polluted Scots pine stand in southwest Finland. Spreading a mulch layer on the soil surface was essential for the recolonization of natural vegetation and increased dwarf shrub survival, partly through protection against drought. Despite initial mortality, transplant establishment was relatively successful during the following 10 yr. Tree species had higher survival rates, but the dwarf shrubs covered a larger area of the soil surface during the experiment. Especially E. nigrum and P. sylvestris proved to be suitable for revegetating heavy metal-polluted and degraded forests. Natural recolonization of pioneer species (e.g., Epilobium angustifolium, Taraxacum coll., and grasses) and tree seedlings (P. sylvestris, Betula sp., and Salix sp.) was strongly enhanced on the mulched plots, whereas there was no natural vegetation on the untreated plots. These results indicate that a heavy metal-polluted site can be ecologically remediated without having to remove the soil. Household compost and woodchips are low-cost mulching materials that are suitable for restoring heavy metal-polluted soil. PMID:17596623

  20. Bioleaching remediation of heavy metal-contaminated soils using Burkholderia sp. Z-90.

    PubMed

    Yang, Zhihui; Zhang, Zhi; Chai, Liyuan; Wang, Yong; Liu, Yi; Xiao, Ruiyang

    2016-01-15

    Bioleaching is an environment-friendly and economical technology to remove heavy metals from contaminated soils. In this study, a biosurfactant-producing strain with capacity of alkaline production was isolated from cafeteria sewer sludge and its capability for removing Zn, Pb, Mn, Cd, Cu, and As was investigated. Phylogenetic analysis using 16S rDNA gene sequences confirmed that the strain belonged to Burkholderia sp. and named as Z-90. The biosurfactant was glycolipid confirmed by thin layer chromatography and Fourier-transform infrared spectroscopy. Z-90 broth was then used for bioleaching remediation of heavy metal-contaminated soils. The removal efficiency was 44.0% for Zn, 32.5% for Pb, 52.2% for Mn, 37.7% for Cd, 24.1% for Cu and 31.6% for As, respectively. Mn, Zn and Cd were more easily removed from soil than Cu, Pb and As, which was attributed to the presence of high acid-soluble fraction of Mn, Zn and Cd and high residual fraction of Cu, Pb and As. The heavy metal removal in soils was contributed to the adhesion of heavy metal-contaminated soil minerals with strain Z-90 and the formation of a metal complex with biosurfactant. PMID:26348147

  1. Combined effect of microwave and activated carbon on the remediation of polychlorinated biphenyl-contaminated soil.

    PubMed

    Liu, Xitao; Yu, Gang

    2006-04-01

    The application of microwave and activated carbon for the treatment of polychlorinated biphenyl (PCB) contaminated soil was explored in this study with a model compound of 2,4,5-trichlorobiphenyl (PCB29). PCB-contaminated soil was treated in a quartz reactor by microwave irradiation at 2450MHz with the addition of granular activated carbon (GAC). In this procedure, GAC acted as microwave absorbent for reaching high temperature and reductant for dechlorination. A sheltered type-K thermocouple was applied to record the temperature rising courses. It was shown that the addition of GAC could effectively promote the temperature rising courses. The determination of PCB residues in soil by gas chromatography (GC) revealed that rates of PCB removal were highly dependent on microwave power, soil moisture content, and the amount of GAC added. GC with mass spectrum (MS) detector and ion chromatography were employed for the analysis of degradation intermediates and chlorine ions, respectively. It was suggested that microwave irradiation with the assistance of activated carbon might be a potential technology for the remediation of PCB-contaminated soil. PMID:16213557

  2. Feasibility of Using Phytoextraction to Remediate a Compost-Based Soil Contaminated with Cadmium.

    PubMed

    Parisien, Michele A; Rutter, Allison; Zeeb, Barbara A

    2015-01-01

    Greenhouse and in-situ field experiments were used to determine the potential for phytoextraction to remediate soil contaminated with Cd from municipal solid waste (MSW) and sewage sludge (SS) compost application at a Peterborough (Canada) site. For the greenhouse experiment, one native (Chenopodium album) and three naturalized (Poa compressa, Brassica juncea, Helianthus annuus) plant species were planted in soil containing no detectable Cd (<1.0 μg·g(-1)), and soil from the site containing low (5.0 ± 0.3 μg·g(-1) Cd), and high (16.5 ± 1.2 μg⋅g(-1) Cd) Cd concentrations. Plant uptake was low (root BAFs ≤0.5) for all species except P. compressa in the low Cd treatment (BAF 1.0). Only B. juncea accumulated Cd in its shoots, though uptake was low (BAF ≤0.3). For the field experiment, B. juncea was planted in-situ in areas of low and high Cd concentrations. Brassica juncea Cd uptake was low (root and shoot BAFs <0.2) in both treatments. Sequential extraction analysis indicated that Cd is retained primarily by low bioavailability soil fractions, and phytoextraction is therefore not feasible at this site. Though low Cd bioavailability has negative implications for Cd phytoextraction from MSW/SS compost-based soils, it may limit receptor exposure to Cd sufficiently to eliminate the potential for risk at this site. PMID:25848836

  3. Remediation of soils contaminated with particulate depleted uranium by multi stage chemical extraction.

    PubMed

    Crean, Daniel E; Livens, Francis R; Sajih, Mustafa; Stennett, Martin C; Grolimund, Daniel; Borca, Camelia N; Hyatt, Neil C

    2013-12-15

    Contamination of soils with depleted uranium (DU) from munitions firing occurs in conflict zones and at test firing sites. This study reports the development of a chemical extraction methodology for remediation of soils contaminated with particulate DU. Uranium phases in soils from two sites at a UK firing range, MOD Eskmeals, were characterised by electron microscopy and sequential extraction. Uranium rich particles with characteristic spherical morphologies were observed in soils, consistent with other instances of DU munitions contamination. Batch extraction efficiencies for aqueous ammonium bicarbonate (42-50% total DU extracted), citric acid (30-42% total DU) and sulphuric acid (13-19% total DU) were evaluated. Characterisation of residues from bicarbonate-treated soils by synchrotron microfocus X-ray diffraction and X-ray absorption spectroscopy revealed partially leached U(IV)-oxide particles and some secondary uranyl-carbonate phases. Based on these data, a multi-stage extraction scheme was developed utilising leaching in ammonium bicarbonate followed by citric acid to dissolve secondary carbonate species. Site specific U extraction was improved to 68-87% total U by the application of this methodology, potentially providing a route to efficient DU decontamination using low cost, environmentally compatible reagents. PMID:23998894

  4. Soil Remediation of an Arsenic-Contaminated Site With Ferrous Sulfate and Type V Portland Cement

    NASA Astrophysics Data System (ADS)

    Illera, V.; O'Day, P. A.; Rivera, N.; Root, R.; Rafferty, M. T.; Vlassopoulos, D.

    2005-12-01

    High levels of arsenic are present in a site adjacent to San Francisco Bay (in East Palo Alto, CA) as a consequence of the activity of a former pesticide manufacturing plant. Most of the readily accessible arsenic at the site has been removed by remedial excavation and surface capping. In-situ fixation of residual arsenic was performed close to the source about 10 years ago where arsenic values in capped soils ranged from 500 to 5000 mg kg-1. The fixation method consisted of the addition of ferrous sulfate (3% w/w), type V Portland cement (10% w/w) and water. Both products were mixed with the contaminated soil to a treatment depth between 1.5 and 9 meters. The treated soil was then capped to prevent weathering. This long-term amended soil offers an opportunity to compare the processes that prevent microbial arsenic reduction and control the immobilization of arsenic in the treated soils versus natural soils, and to study the aging effects of arsenic sorption. Solid phase characterization of soil samples from both the field and controlled laboratory experiments were carried out to study the speciation and bioavailability of arsenic and to ascertain the mechanisms of the arsenic immobilization in the treated soil. These methods included physical description by field observations, X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy, total elemental concentrations, and solid phase fractionation by sequential extraction. Both synchrotron X-ray absorption spectroscopy (XAS) and XRD measurements were used to determine oxidation state of arsenic and iron and host phases present in the soil. The remedial treatment was successful in immobilizing the arsenic in the contaminated soil, and decreasing its leachability. Measurements taken at short aging times (during the first month) showed that the treatment was effective in reducing leachable arsenic as evidenced by the TCLP wet test (< 5 mg l-1 leached). The field amendment influenced

  5. Sustainability appraisal tools for soil and groundwater remediation: how is the choice of remediation alternative influenced by different sets of sustainability indicators and tool structures?

    PubMed

    Beames, Alistair; Broekx, Steven; Lookman, Richard; Touchant, Kaat; Seuntjens, Piet

    2014-02-01

    The state-of-the-science in sustainability assessment of soil and groundwater remediation is evaluated with the application of four decision support systems (DSSs) to a large-scale brownfield revitalization case study. The DSSs were used to perform sustainability appraisals of four technically feasible remediation alternatives proposed for the site. The first stage of the review compares the scope of each tool's sustainability indicators, how these indicators are measured and how the tools differ in terms of standardization and weighting procedures. The second stage of the review compares the outputs from the tools and determines the key factors that result in differing results between tools. The evaluation of indicator sets and tool structures explains why the tools generate differing results. Not all crucial impact areas, as identified by sustainable remediation forums, are thoroughly considered by the tools, particularly with regard to the social and economic aspects of sustainability. Variations in boundary conditions defined between technologies, produce distorted environmental impact results, especially when in-situ and ex-situ technologies are compared. The review draws attention to the need for end users to be aware of which aspects of sustainability are considered, how the aspects are measured and how all aspects are ultimately balanced in the evaluation of potential remediation strategies. Existing tools can be improved by considering different technologies within the same boundary conditions and by expanding indicator sets to include indicators deemed to be relevant by remediation forums. PMID:24239816

  6. APPLICATION OF THE LASAGNA{trademark} SOIL REMEDIATION TECHNOLOGY AT THE DOE PADUCAH GASEOUS DIFFUSION PLANT

    SciTech Connect

    Swift, Barry D.; Tarantino, Joseph J., P. E.

    2003-02-27

    The Paducah Gaseous Diffusion Plant (PGDP), owned by the Department of Energy (DOE), has been enriching uranium since the early 1950s. The enrichment process involves electrical and mechanical components that require periodic cleaning. The primary cleaning agent was trichloroethene (TCE) until the late 1980s. Historical documentation indicates that a mixture of TCE and dry ice were used at PGDP for testing the integrity of steel cylinders, which stored depleted uranium. TCE and dry ice were contained in a below-ground pit and used during the integrity testing. TCE seeped from the pit and contaminated the surrounding soil. The Lasagna{trademark} technology was identified in the Record of Decision (ROD) as the selected alternative for remediation of the cylinder testing site. A public-private consortium formed in 1992 (including DOE, the U.S. Environmental Protection Agency, and the Kentucky Department for Environmental Protection, Monsanto, DuPont, and General Electric) developed the Lasagna{trademark} technology. This innovative technology employs electrokinetics to remediate soil contaminated with organics and is especially suited to sites with low permeability soils. This technology uses direct current to move water through the soil faster and more uniformly than hydraulic methods. Electrokinetics moves contaminants in soil pore water through treatment zones comprised of iron filings, where the contaminants are decomposed to basic chemical compounds such as ethane. After three years of development in the laboratory, the consortium field tested the Lasagna{trademark} process in several phases. CDM installed and operated Phase I, the trial installation and field test of a 150-square-foot area selected for a 120-day run in 1995. Approximately 98 percent of the TCE was removed. CDM then installed and operated the next phase (IIa), a year-long test on a 600-square-foot site. Completed in July 1997, this test removed 75 percent of the total volume of TCE down to a

  7. Evaluation of electrode configuration and mode of DC power for improvement of electrokinetic soil remediation

    NASA Astrophysics Data System (ADS)

    Kim, Soon-Oh; Lee, Woo Chun; Lee, Sang Woo; Lee, Byung-Tae

    2014-05-01

    Electrokinetic soil remediation is also called electrokinetic soil processing, electroreclamation, and electrochemical decontamination. The electrokinetic technique needs a low-level direct current of the order of mA/cm2 between electrodes to remove contaminants. The electrokinetic technique is one of the most promising remediation processes, and offers high efficiency and time effectiveness in the decontamination of low-permeability soils contaminated with heavy metals, radionuclides, or organic compounds. The significance of this technique is attributed to its low operational cost and potential applicability to a wide range of contaminant types, and these benefits have resulted in the initiation of numerous studies into its use for waste remediation. Electrode configuration is crucial for cost-effectiveness and overall efficacy of the elelectrokinetic processing, particularly in its field implementation. We investigated the effectiveness of various electrode arrays which can be grouped into one-dimensional (1-D) and two-dimensional (2-D) ones. Normally, the DC electricity of full wave has been used to remove contaminants from soils using elelectrokinetic processing. However, application of half-wave DC power can be also taken into account to improve efficacy of the processing, because it generates pulse power and accelerates the migration of contaminants within soils. We empirically evaluated the effect of type of DC electricity on the overall performance of the electrokinetic soil processing. The 1-D configuration with 5 electrode pairs showed the least total electric power, but that consumed in only the soil cell was less in the 2-D arrays than in 1-D ones. Particularly, most of the electric power is likely to be consumed in the electrode compartments, and the electric resistance in the electrode parts should be reduced to save the electric energy cost in the whole processing. In terms of removal efficiencies of 5 heavy metal contaminants, overall efficiency

  8. Degradation of oil products in a soil from a Russian Barents hot-spot during electrodialytic remediation.

    PubMed

    Pedersen, Kristine B; Lejon, Tore; Jensen, Pernille E; Ottosen, Lisbeth M

    2016-01-01

    A highly oil-polluted soil from Krasnoe in North-West Russia was used to investigate the degradation of organic pollutants during electrodialytic remediation. Removal efficiencies were up to 70 % for total hydrocarbons (THC) and up to 65 % for polyaromatic hydrocarbons (PAH). Relatively more of the lighter PAH compounds and THC fractions were degraded. A principal component analysis (PCA) revealed a difference in the distribution of PAH compounds after the remediation. The observed clustering of experiments in the PCA scores plot was assessed to be related to the stirring rate. Multivariate analysis of the experimental settings and final concentrations in the 12 experiments revealed that the stirring rate of the soil suspension was by far the most important parameter for the remediation for both THC and PAH. Light was the second most important variable for PAH and seems to influence degradation. The experimental variables current density and remediation time did not significantly influence the degradation of the organic pollutants. Despite current density not influencing the remediation, there is potential for degrading organic pollutants during electrodialytic removal of heavy metals, as long as a stirred set-up is applied. Depending on remediation objectives, further optimisation may be needed in order to develop efficient remediation strategies. PMID:27026865

  9. SITE DEMONSTRATION OF STEAM ENHANCED REMEDIATION (SER) AT THE PORT OF RIDGEFIELD

    EPA Science Inventory

    This technology evaluation is being conducted by the U.S. Environmental Protection Agency (U.S.EPA) Superfund Innovative Technology Evaluation (SITE) Program. SER is an in-situ thermal treatment soil cleanup technology that will be applied through installation of a steam injectio...

  10. Effect of oxidant dosage on integrated electrochemical remediation of contaminant mixtures in soils.

    PubMed

    Reddy, Krishna R; Karri, Madhusudhana R

    2008-07-01

    Many sites are contaminated with contaminant mixtures, commonly heavy metals and polycyclic aromatic hydrocarbons (PAHs), which pose a great challenge for remediation. The objective of this research was to investigate coupled Fenton-like oxidation and electrokinetic remediation of low permeability soils contaminated with both heavy metals and PAHs. This remediation process aims at simultaneous oxidation of organic contaminants and removal of heavy metals. Fenton's reagent, consisting of hydrogen peroxide (H(2)O(2)) and native iron catalyst, is utilized for chemical oxidation. Laboratory batch and electrokinetic experiments were performed on kaolin (a low permeability soil) spiked with nickel and phenanthrene each at a concentration of 500 mg/kg of dry soil to represent typical heavy metal and PAH contaminants found at contaminated sites. Experiments were conducted using H(2)O(2) solution in 5%, 10%, 20% and 30% concentrations and also using deionized (DI) water as control. For electrokinetic experiments, a voltage gradient of 1 VDC/cm was applied and H(2)O(2) solution was introduced at the anode for a total duration of four weeks. Batch tests showed that phenanthrene oxidation increases from 76% to 87% when the H(2)O(2) concentration increases from 5% to 30%. The electrokinetic experiments showed substantial electroosmotic flow in all the tests. Approximately one pore volume of flow was generated in the DI baseline test and about 1.2-1.6 pore volumes were generated in case of H(2)O(2) tests. Phenanthrene was partially oxidized in the H(2)O(2) tests and its removal from the soil was insignificant. Oxidation of phenanthrene increased with increasing concentration of H(2)O(2); a maximum of 56% oxidation was observed with 30% H(2)O(2). Nickel migrated from anode to cathode. This migration was more pronounced in the H(2)O(2) tests as compared to the DI baseline test. Nickel precipitated in all the tests near the cathode due to high pH conditions. These results emphasize

  11. Measurement systems in the area of land remediation and soil segregation activities

    SciTech Connect

    Simon, Gerold G.; Sokcic-Kostic, Marina; Auler, Ingolf; Eickelpasch, Ludger; Betts, Jonathan

    2007-07-01

    Available in abstract form only. Full text of publication follows: The remediation of radioactively contaminated land is a small but growing sector in the area of decommissioning of nuclear facilities. This also includes the material from buildings after demolition. Contamination comprises in general alpha and beta activities and emission of alpha, beta and gamma radiation. The measurement is in practice restricted to the measurement of gamma emission, because of the high penetration of material by gamma rays. All isotopes, which do not emit gammas are estimated on the basis of given relation between alpha and beta emitters without gamma radiation and emitters with gamma radiation. This method is called 'key nuclide method'. Whilst many studies have been completed, others still continue in the processing of large volumes of concrete, steel and soil. An important conclusion from these and similar research programs is that a significant proportion of the waste contains only low concentrations of radioactive nuclides. Therefore, much of the material from the remediation can be considered for 'free release'. It was often not possible to attain adequate specific information on these materials, so a measurement system is needed for their classification and characterization. NUKEM Technologies has practical experience in characterising and remediating of nuclear sites. Recently, it has pioneered the use of innovative in-situ and ex-situ characterisation and waste segregation technologies, which enhance the efficiency of remedial actions and provide assurance to customers, regulators and the public that all significant contamination has been removed and sites can be used for new purposes. (authors)

  12. NATO/CCMS pilot study on demonstration of remedial-action technologies for contaminated land and ground water: 1988 activities

    SciTech Connect

    Sanning, D.E.; Smith, M.A.; Bell, R.M.

    1988-01-01

    The paper describes the nature, structure and content of the NATO Committee on the Challenges of Modern Society (CCMS) Pilot Study Demonstration of Remedial Action Technologies for Contaminated Land and Groundwater and the associated CCMS Fellowship program. To date, twelve projects in six countries have been selected for inclusion in the program which will involve periodic expert review during the five years for which the project will run. The paper draws special attention to the work on microbial clean up techniques included in the program, and the outcome of the first international meeting held in Washington, D.C. in 1987.

  13. [Continuous remediation of heavy metal contaminated soil by co-cropping system enhanced with chelator].

    PubMed

    Wei, Ze-Bin; Guo, Xiao-Fang; Wu, Qi-Tang; Long, Xin-Xian

    2014-11-01

    In order to elucidate the continuous effectiveness of co-cropping system coupling with chelator enhancement in remediating heavy metal contaminated soils and its environmental risk towards underground water, soil lysimeter (0.9 m x 0.9 m x 0.9 m) experiments were conducted using a paddy soil affected by Pb and Zn mining in Lechang district of Guangdong Province, 7 successive crops were conducted for about 2.5 years. The treatments included mono-crop of Sedum alfredii Hance (Zn and Cd hyperaccumulator), mono-crop of corn (Zea mays, cv. Yunshi-5, a low-accumulating cultivar), co-crop of S. alfredii and corn, and co-crop + MC (Mixture of Chelators, comprised of citric acid, monosodium glutamate waste liquid, EDTA and KCI with molar ratio of 10: 1:2:3 at the concentration of 5 mmol x kg(-1) soil). The changes of heavy metal concentrations in plants, soil and underground water were monitored. Results showed that the co-cropping system was suitable only in spring-summer seasons and significantly increased Zn and Cd phytoextraction. In autumn-winter seasons, the growth of S. alfredii and its phytoextraction of Zn and Cd were reduced by co-cropping and MC application. In total, the mono-crops of S. alfredii recorded a highest phytoextraction of Zn and Cd. However, the greatest reduction of soil Zn, Cd and Pb was observed with the co-crop + MC treatment, the reduction rates were 28%, 50%, and 22%, respectively, relative to the initial soil metal content. The reduction of this treatment was mainly attributed to the downwards leaching of metals to the subsoil caused by MC application. The continuous monitoring of leachates during 2. 5 year's experiment also revealed that the addition of MC increased heavy metal concentrations in the leaching water, but they did not significantly exceed the III grade limits of the underground water standard of China. PMID:25639110

  14. Process challenges in rotary kiln-based incinerators in soil remediation projects

    SciTech Connect

    Acharya, P.; Fogo, D.; McBride, C.

    1996-12-31

    Most Superfund sites undergoing thermal remediation consist of high-moisture content (15 to 40 percent) soils having light organic contamination (low-heat content). In the early 1980s, the rotary kiln incinerators employed at these Superfund sites were relatively small mobile hazardous waste incinerators (HWI) built on standard-size semi-trailers. As the industry matured over the past ten years, competition has driven the industry to larger and more efficient rotary kiln systems that minimize the cost per ton of soil treated by increasing the throughput rates and shortening on-site processing time. Because these units are transported from site to site by truck or a combination of rail and truck, the rotary kiln outside shell diameters have peaked to approximately 13.5 feet. Now the focus has shifted to increasing the processing capacity of these existing, maximized fixed-sized systems. Such actions include the use of oxygen-based combustion systems, which increase the throughput and efficiency by improving heat transfer and reducing the volume of combustion gas requiring treatment. However, despite the experience and expertise gained by the participants in the thermal remediation industry, many of the same process challenges still remain. This article discusses these process challenges facing the industry and potential solutions, based on data from IT`s Hybrid Thermal Treatment System{reg_sign} HTTS{reg_sign} and other sources. 10 refs., 2 figs., 3 tabs.

  15. 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

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

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

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

  17. IPEC Gels for Remediating Soils Contaminated as Result of Nuclear and Industrial Activities

    SciTech Connect

    Mikheykin, S.V.; Anciferova, E.Yu.; Simonov, V.P.; Zezin, A.B.; Rogacheva, V.B.; Bolusheva, T.N.

    2006-07-01

    Under International Scientific and Technological Center (ISTC, Moscow) Project no. 1567 the Moscow research team in collaboration with Los Alamos National Laboratory developed and tested new kind of inter-polyelectrolyte complexes with micro-gel (IPECs) for soil surface stabilization, prevention of radioactive contamination distribution with wind and water streams and for site remediation using mixtures of new water-soluble polymers with seeding grasses. Evidently, the most important factor responsible for the effectiveness of a polymeric aggregator is the ratio of the size of poly-complex particles to that of dispersion particles being aggregated. The particle size of IPEC produced of a pair of linear oppositely charged poly-electrolytes is usually fractions of a micron. Such a particle can fix only small aggregates ({approx}10 {mu}m and less). One of the ways of improving poly-complex aggregators is to use loose cross-linked poly-electrolytic gels as an IPEC component. When generating/dispersing these poly-electrolytic gels, particles of specified sizes can be produced. These poly-electrolytic micro-gels introduced into soil save moisture, what is important for arid sites. Wind erosion was studied as a function of soil physical-chemical properties and the air stream velocity. A laboratory wind tunnel instrumented to follow the process on a real-time basis was used for our study. Polymer-treated samples show a high wind erosion resistance in the wind velocity range up to 40 m/s. The micro-gel dispersion MGD-2 was injected in combination with MLA-1 in the experiments with water flow - water erosion resistance. With an increase in the water-polymer solution application rate from 2.0 to 4.0 l/m{sup 2} the soil resistance to eroding water streams with velocity of 55 cm/s (2.0 l/m{sup 2}) and at 70.0 cm/s with 4.0 l/m{sup 2}. Based on the classification of soils by erosion resistance, soils eroded with a water stream 1 cm high at a velocity of 50 cm/s are considered to

  18. Synergistic influence of Vetiveria zizanioides and selected rhizospheric microbial strains on remediation of endosulfan contaminated soil.

    PubMed

    Singh, Vandana; Singh, Pratiksha; Singh, Nandita

    2016-09-01

    Application of endosulfan tolerant rhizospheric bacterial strain isolated from pesticide contaminated area, Ghaziabad in combination with V. zizanioides for the remediation of endosulfan is described herein. The dissipation of endosulfan from soil was considerably enhanced in the presence of bacterial strain and Vetiveria zizanioides together when compared to the dissipation in presence of either of them alone. Four strains- EAG-EC-12 (M1), EAG-EC-13(M2), EAG-EC-14(M3) and EAG-EC-15(M4) are used for this purpose. V. zizanioides was grown in garden soil spiked with 1500 µg g(-1) of endosulfan and inoculated with 100 ml of microbial culture of above motioned strains. Effect of microbial inoculation on plant growth, endosulfan uptake and endosulfan removal efficiency were analyzed. The microbial inoculation significantly enhances the growth of test plant and endosulfan dissipation from soil (p < 0.05). The addition of bacterial strain M1, M2, M3 and M4 in treated pots showed enhanced root length by 13, 33 35, 20.2 and 4.3 %, above ground plant length by 16.38, 35.56, 24.92 and 9.8 % and biomass by 33.69, 49.63, 39.24 and 17.09 % respectively when compared with endosulfan treated plants. After 135 days of exposure, a decline in endosulfan concentration by 59.12, 64.56, 62.69 and 56.39 % was obtained in the spiked soil inoculated with bacterial strains M1, M2, M3 and M4 respectively whereas, decrease in endosulfan concentration by 72.78, 85.25, 76.91 and 65.44 % in the vegetative spiked soil inoculated with same strains was observed during same exposure period. After 135 days of growth period, enhanced removal of endosulfan from experimental soil by 13.66, 20.69, 14.22 and 9.05 % was found in vegetative experiment inoculated with same strains when compared with non vegetative experiment. Result of the study showed that use of toletant plant and tolerant bacterial strains could be the better strategy for the remediation of endosulfan contaminated soil. PMID

  19. DEMONSTRATION BULLETIN: SOIL/SEDIMENT WASHING SYSTEM BERGMANN USA

    EPA Science Inventory

    The Bergmann USA Soil/Sediment Washing System is a waste minimization technique designed to separate or "partition" soils and sediments by grain size and density. In this water-based volume reduction process, hazardous contaminants are concentrated into a small residual portion...

  20. Demonstration of the Fenton Reaction

    ERIC Educational Resources Information Center

    Luehrs, Dean C.; Roher, Alex E.

    2007-01-01

    The study demonstrates the Fenton reaction, which is carried out using the Fenton reagent that is used for groundwater and soil remediation. The Fenton reaction can be implicated in DNA damage, Alzheimer's disease, cardiovascular disease and ageing in general.

  1. Demonstration of Combined Zero-Valent Iron and Electrical Resistance Heating for In Situ Trichloroethene Remediation

    SciTech Connect

    Truex, Michael J.; Macbeth, Tamzen; Vermeul, Vincent R.; Fritz, Brad G.; Mendoza, Donaldo P.; Mackley, Rob D.; Wietsma, Thomas W.; Sandberg, Greg; Powell, Thomas; Powers, Jeff; Pitre, Emile; Michalsen, Mandy M.; Ballock-Dixon, Sage; Zhong, Lirong; Oostrom, Martinus

    2011-06-27

    The effectiveness of in situ treatment using zero-valent iron to remediate sites with non-aqueous phase or significant sediment-associated contaminant mass can be limited by relatively low rates of mass transfer to bring contaminants in contact with the reactive media. For a field test in a trichloroethene source area, combining moderate-temperature (maximum 50oC) subsurface electrical resistance heating with in situ ZVI treatment was shown to accelerate dechlorination and dissolution rates by a factor of 4 to 6 based on organic daughter products and a factor 8-16 using a chloride concentrations. A mass-discharge-based analysis was used to evaluate reaction, dissolution, and volatilization at ambient groundwater temperature (~10oC) and as temperature was increased up to about 50oC. Increased reaction and contaminant dissolution were observed with increased temperature, but volatilization was minimal during the test because in situ reactions maintained low aqueous-phase TCE concentrations.

  2. Countercurrent soil washing system for remediation of viscous hydrocarbons, heavy metals, radionuclides

    SciTech Connect

    Kuhlman, M.I.; Karlsson, M.K.; Downie, C.A.

    1995-12-31

    Drying augers and multicell DAF tanks are excellent machines in which to countercurrently wash soil and remove hazardous hydrocarbons, metals or radionuclides. An auger works well because it preferentially moves soil along one side of its trough. Thus, when enough high pressure and temperature water jets are placed along that path, contaminants can be melted, or dissolved and scoured from the soil. Contaminants and fines flow down the opposite side of the auger and out for extraction in a series of flotation tanks. Countercurrent washing of the silt results when soil settles in tanks through rising water and air bubbles then is pumped through cyclones placed above the next DAF tank of the series. LNAPLs, DNAPLs, or metallic contaminants made hydrophobic by chemicals in the system are removed at the overflow of the cyclones or by flotation in the tanks. The overflow from the cyclones and DAF tanks flows into the previous tank of the series. Examples of contaminants remediated include; arsenic, cadmium, lead and mercury, Naturally Occurring Radioactive Materials (NORM), uranium, solid oils, polyaromatic hydrocarbons in creosote and coal tars, and polychlorinated hydrocarbons.

  3. Natural attenuation processes for remediation of arsenic contaminated soils and groundwater.

    PubMed

    Wang, Suiling; Mulligan, Catherine N

    2006-12-01

    Arsenic (As) contamination presents a hazard in many countries. Natural attenuation (NA) of As-contaminated soils and groundwater may be a cost-effective in situ remedial option. It relies on the site intrinsic assimilative capacity and allows in-place cleanup. Sorption to solid phases is the principal mechanism immobilizing As in soils and removing it from groundwater. Hydroxides of iron, aluminum and manganese, clay and sulfide minerals, and natural organic matter are commonly associated with soils and aquifer sediments, and have been shown to be significant As adsorbents. The extent of sorption is influenced by As speciation and the site geochemical conditions such as pH, redox potential, and the co-occurring ions. Microbial activity may catalyze the transformation of As species, or mediate redox reactions thus influencing As mobility. Plants that are capable of hyperaccumulating As may translocate As from contaminated soils and groundwater to their tissues, providing the basis for phytoremediation. However, NA is subject to hydrological changes and may take substantial periods of time, thus requiring long-term monitoring. The current understanding of As NA processes remains limited. Sufficient site characterization is critical to the success of NA. Further research is required to develop conceptual and mathematical models to predict the fate and transport of As and to evaluate the site NA capacity. Engineering enhanced NA using environmentally benign products may be an effective alternative. PMID:17049728

  4. The risk implications of approaches to setting soil remediation goals at hazardous waste contaminated sites

    SciTech Connect

    Labieniec, P.A.

    1994-08-01

    An integrated exposure and carcinogenic risk assessment model for organic contamination in soil, SoilRisk, was developed and used for evaluating the risk implications of both site-specific and uniform-concentration approaches to setting soil remediation goals at hazardous-waste-contaminated sites. SoilRisk was applied to evaluate the uncertainty in the risk estimate due to uncertainty in site conditions at a representative site. It was also used to evaluate the variability in risk across a region of sites that can occur due to differences in site characteristics that affect contaminant transport and fate when a uniform concentration approach is used. In evaluating regional variability, Ross County, Ohio and the State of Ohio were used as examples. All analyses performed considered four contaminants (benzene, trichloroethylene (TCE), chlordane, and benzo[a]pyrene (BAP)) and four exposure scenarios (commercial, recreational and on- and offsite residential). Regardless of whether uncertainty in risk at a single site or variability in risk across sites was evaluated, the exposure scenario specified and the properties of the target contaminant had more influence than variance in site parameters on the resulting variance and magnitude of the risk estimate. In general, variance in risk was found to be greater for the relatively less degradable and more mobile of the chemicals studied (TCE and chlordane) than for benzene which is highly degradable and BAP which is very immobile in the subsurface.

  5. Accumulation of heavy metals from contaminated soil to plants and evaluation of soil remediation by vermiculite.

    PubMed

    Malandrino, Mery; Abollino, Ornella; Buoso, Sandro; Giacomino, Agnese; La Gioia, Carmela; Mentasti, Edoardo

    2011-01-01

    We evaluated the distribution of 15 metal ions, namely Al, Cd, Cu, Cr, Fe, La, Mn, Ni, Pb, Sc, Ti, V, Y, Zn and Zr, in the soil of a contaminated site in Piedmont (Italy). This area was found to be heavily contaminated with Cu, Cr and Ni. The availability of these metal ions was studied using Tessier's sequential extraction procedure: the fraction of mobile species, which potentially is the most harmful for the environment, was much higher than that normally present in unpolluted soils. This soil was hence used to evaluate the effectiveness of treatment with vermiculite to reduce the availability of the pollutants to two plants, Lactuca sativa and Spinacia oleracea, by pot experiments. The results indicated that the addition of vermiculite significantly reduces the uptake of metal pollutants by plants, confirming the possibility of using this clay in amendment treatments of metal-contaminated soils. The effect of plant growth on metal fractionation in soils was investigated. Finally, the sum of the metal percentages extracted into the first two fractions of Tessier's protocol was found to be suitable in predicting the phytoavailability of most of the pollutants present in the investigated soil. PMID:21055788

  6. DEMONSTRATION OF PILOT-SCALE PERVAPORATION SYSTEMS FOR VOLATILE ORGANIC COMPOUND REMOVAL FROM A SURFACTANT ENHANCED AQUIFER REMEDIATION FLUID. II. HOLLOW FIBER MEMBRANE MODULES

    EPA Science Inventory

    Pilot-scale demonstration of pervaporation-based removal of volatile organic compounds from a surfactant enhanced aquifer remediation (SEAR) fluid has been conducted at USEPA's Test & Evaluation Facility using hollow fiber membrane modules. The membranes consisted of microporous...

  7. Sorption of priority pollutants to biochars and activated carbons for application to soil and sediment remediation

    NASA Astrophysics Data System (ADS)

    Beckingham, B.; Gomez-Eyles, J. L.; Kwon, S.; Riedel, G.; Gilmour, C.; Ghosh, U.

    2012-04-01

    The effectiveness of different biochars in comparison to 2 commercially available activated carbons (ACs) to sorb polychlorinated biphenyls (PCBs) and mercury (Hg) was assessed, with the aim of identifying promising materials for application to soil and sediment remediation and elucidating material properties that may enhance pollutant binding potential. Biochars studied were produced from pine dust, peanut hull, barley straw, and acai pit in addition to steam-activated biochars made from poultry litter (chicken and turkey). Aqueous concentrations of PCBs were measured using a polyoxymethylene passive sampling technique allowing a very low environmentally-relevant concentration range to be examined. Mercury pH-edge isotherms were conducted at relatively high concentrations in a wide pH range (pH 3-11). Sorption of Hg at low concentrations was also performed with ACs and two other biochars made from a marsh reed and a hard wood. Organic contaminant isotherms were analyzed by the Freundlich model, and Freundlich sorption coefficients (KFr) were normalized to a single concentration to allow comparison among materials (i.e. Kd). Values of Kd were related to the sorbent surface area, with sorption being greater for ACs than activated biochars, followed by unactivated biochars. ACs also had higher carbon content (80-90%) than biochars (22 - 77%). This sorption trend would thus be expected for adsorption of hydrophobic compounds to black carbon surfaces. In contrast, at high concentration all biochars removed more Hg from solution than ACs. Steam-activated poultry litter biochars showed the best performance, with consistent removal of >99.7% Hg over the entire pH range. The relatively high sulfur and phosphate content of these materials likely contribute to this enhanced Hg sorption. Also, owing to their lower pyrolysis temperatures relative to ACs, biochars are reported to have a greater surface group functionality which can enhance cation sorption. The importance of

  8. In-situ remediation of soil contaminated with low concentrations of radionuclides

    SciTech Connect

    Entry, J.A.; Vance, N.C.; Hamilton, M.A.; Zabowski, D.

    1994-12-31

    Since plants are known to take up and accumulate {sup 37}Cs and {sup 90}Sr, removal of these radionuclides from contaminated soils by plants would provide a reliable and economical method of remediation. One approach is to use fast-growing, perennial plants combined with specific mycorrhizal fungi to maximize plant accumulation and removal of {sup 137}Cs and {sup 90}Sr from contaminated soils. The objective is to find a series of plants that can quickly accumulate and remove radionuclides from soils. Specific mycorrhizal fungi inoculated onto plants should enhance the uptake of {sup 137}Cs and {sup 90}Sr. Laboratory studies indicate that certain plants may be able to remove radionuclides, especially {sup 137}Cs and {sup 90}Sr, from soil over a period of less than 10 yr. In addition, one could change the physical and chemical properties of the soil to enhance the availability of {sup 137}Cs and {sup 90}Sr to plants while decreasing the mobility of these radionuclides in soil. The above-ground portion of perennial plants would be harvested. High-temperature combustion would be used to oxidize plant material, concentrating {sup 137}Cs and {sup 90}Sr in ash for disposal. One of the many strengths of this method is its applicability to any terrestrial environment. Transportation of radionuclides from the site could be minimized through plant management, selection of plants that are less palatable to grazing animals, and fencing. Environmental conditions will change with each site; however, radionuclide accumulation could be accomplished by plants that are adapted to a wide spectrum of environmental conditions. There is no other practical and economic method to remove these radionuclides form the vast areas of land that have been contaminated by nuclear testing and nuclear reactor accidents.

  9. The development and testing of technologies for the remediation of mercury-contaminated soils, Task 7.52. Topical report, December 1992--December 1993

    SciTech Connect

    Stepan, D.J.; Fraley, R.H.; Charlton, D.S.

    1994-02-01

    The release of elemental mercury into the environment from manometers that are used in the measurement of natural gas flow through pipelines has created a potentially serious problem for the gas industry. Regulations, particularly the Land Disposal Restrictions (LDR), have had a major impact on gas companies dealing with mercury-contaminated soils. After the May 8, 1993, LDR deadline extension, gas companies were required to treat mercury-contaminated soils by designated methods to specified levels prior to disposal in landfills. In addition, gas companies must comply with various state regulations that are often more stringent than the LDR. The gas industry is concerned that the LDRs do not allow enough viable options for dealing with their mercury-related problems. The US Environmental Protection Agency has specified the Best Demonstrated Available Technology (BDAT) as thermal roasting or retorting. However, the Agency recognizes that treatment of certain wastes to the LDR standards may not always be achievable and that the BDAT used to set the standard may be inappropriate. Therefore, a Treatability Variance Process for remedial actions was established (40 Code of Federal Regulations 268.44) for the evaluation of alternative remedial technologies. This report presents evaluations of demonstrations for three different remedial technologies: a pilot-scale portable thermal treatment process, a pilot-scale physical separation process in conjunction with chemical leaching, and a bench-scale chemical leaching process.

  10. ACTIVE SOIL DEPRESSURIZATION (ASD) DEMONSTRATION IN A LARGE BUILDING

    EPA Science Inventory

    The report gives results of an evaluation of the feasibility of implementing radon resistant construction techniques -- especially active soil depressurization (ASD) -- in new large buildings in Florida. Indoor radon concentrations and radon entry were monitored in a finished bui...

  11. Probabilistic comparison of alternative characterization technologies at the Fernald Uranium-in-Soils Integrated Demonstration Project

    SciTech Connect

    Rautman, C.A.; McGraw, M.A.; Istok, J.D.; Sigda, J.M.; Kaplan, P.G.

    1993-12-31

    The performance of four alternative characterization technologies proposed for use in characterization of surficial uranium contamination in soil at the Incinerator and Drum Baling Areas at the Fernald Environmental Management Project in southwestern Ohio has been evaluated using a probabilistic, risk-based decision-analysis methodology. The basis of comparison is to minimize a computed total cost for environmental cleanup. This total-cost-based approach provides a framework for evaluating the trade-offs among remedial investigation, the remedial design, and the risk of regulatory penalties. The approach explicitly recognizes the value of information provided by remedial investigation; additional measurements are only valuable to the extent that the information they provide reduces total cost.

  12. Sampling errors associated with soil composites used to estimate mean Ra-226 concentrations at an UMTRA remedial-action site

    SciTech Connect

    Gilbert, R.O.; Baker, K.R.; Nelson, R.A.; Miller, R.H.; Miller, M.L.

    1987-07-01

    The decision whether to take additional remedial action (removal of soil) from regions contaminated by uranium mill tailings involves collecting 20 plugs of soil from each 10-m by 10-m plot in the region and analyzing a 500-g portion of the mixed soil for /sup 226/Ra. A soil sampling study was conducted in the windblown mill-tailings flood plain area at Shiprock, New Mexico, to evaluate whether reducing the number of soil plugs to 9 would have any appreciable impact on remedial-action decisions. The results of the Shiprock study are described and used in this paper to develop a simple model of the standard deviation of /sup 226/Ra measurements on composite samples formed from 21 or fewer plugs. This model is used to predict as a function of the number of soil plugs per composite, the percent accuracy with which the mean /sup 226/Ra concentration in surface soil can be estimated, and the probability of making incorrect remedial action decisions on the basis of statistical tests. 8 refs., 15 figs., 9 tabs.

  13. GLASS FORMULATION DEVELOPMENT AND TESTING FOR COLD CRUCIBLE INDUCTION MELTER (CCIM) ADVANCED REMEDIATION TECHNOLOGIES DEMONSTRATION PROJECT - 9208

    SciTech Connect

    Marra, J; Amanda Billings, A; David Peeler, D; Michael Stone, M; Tommy Edwards, T

    2008-08-27

    Over the past few years, Cold Crucible Induction Melter (CCIM) demonstrations have been completed using SRS sludge batches 2, 3 and 4 (SB2, SB3 and SB4) simulant compositions. These campaigns demonstrated the ability of the CCIM to effectively produce quality glasses at high waste loadings. The current Advanced Remediation Technology (ART) Phase II-A Project is aimed at demonstrating the CCIM technology under representative DWPF flowsheet conditions and to demonstrate extended operations of the melter. A glass composition development effort was completed to identify and recommend a frit composition and sludge batch 4 (SB4) simulant waste loading target for subsequent ART-Phase II-A CCIM demonstration testing. Based on the results of the glass formulation testing, it was recommended that the Frit 503-R6 composition (B{sub 2}O{sub 3} = 14 wt %; Li{sub 2}O = 9 wt %; Na{sub 2}O = 3 wt %; and SiO{sub 2} = 74 wt %) be utilized for the demonstration. Furthermore, a waste loading of 46 wt % was recommended. The recommended frit and waste loading would produce a glass with acceptable durability with a liquidus temperature adequately below the 1250 C nominal CCIM operating temperature. This frit composition and waste loading was found to result in a glass that met CCIM processing requirements for viscosity, electrical conductivity and thermal conductivity. The recommended frit and waste loading level should also provide a buffer for sludge product compositional variation to support the Phase II-A CCIM demonstration.

  14. Solid/solution Cu fractionations/speciation of a Cu contaminated soil after pilot-scale electrokinetic remediation and their relationships with soil microbial and enzyme activities.

    PubMed

    Wang, Quan-Ying; Zhou, Dong-Mei; Cang, Long; Li, Lian-Zhen; Wang, Peng

    2009-01-01

    The aim of this study was to investigate the detailed metal speciation/fractionations of a Cu contaminated soil before and after electrokinetic remediation as well as their relationships with the soil microbial and enzyme activities. Significant changes in the exchangeable and adsorbed-Cu fractionations occurred after electrokinetic treatment, while labile soil Cu in the solution had a tendency to decrease from the anode to the cathode, and the soil free Cu(2+) ions were mainly accumulated in the sections close to the cathode. The results of regression analyses revealed that both the soil Cu speciation in solution phase and the Cu fractionations in solid phase could play important roles in the changes of the soil microbial and enzyme activities. Our findings suggest that the bioavailability of soil heavy metals and their ecotoxicological effects on the soil biota before and after electroremediation can be better understood in terms of their chemical speciation and fractionations. PMID:19427727

  15. DEMONSTRATION AND EVALUATION OF INNOVATIVE REMEDIATION TECHNOLOGIES THROUGH THE EPA SITE PROGRAM

    EPA Science Inventory

    The Superfund Innovative Technology Evaluation (SITE) Program has successfuly promoted the development, commercialization and implementation of innovative hazardous waste treatment technologies for 18 years. SITE offers a mechanism for conducting joint technology demonstration an...

  16. Sorption interactions of heavy metals with biochar in soil remediation studies

    NASA Astrophysics Data System (ADS)

    Fristak, Vladimir; Friesl-Hanl, Wolfgang; Wawra, Anna; Soja, Gerhard

    2015-04-01

    The search for new materials in soil remediation applications has led to new conversion technologies such as carbonization and pyrolysis. Biochar represents the pyrolytic product of different biomass input materials processed at 350-1000°C and anoxic conditions. The pyrolysis temperature and feedstock have a considerable influence on the quality of the charred product and also its main physico-chemical properties. Biochar as porous material with large specific surface and C-stability is utilized in various environmental and agricultural technologies. Carbon sequestration, increase of soil water-holding capacity and pH as well as sorption of different xenobiotics present only a fraction of the multitude of biochar application possibilities. Heavy metals as potential sources of ecotoxicological risks are characterized by their non-degradability and the potential transfer into the food chain. Carbonaceous materials have been used for a long time as sorbents for heavy metals and organic contaminants in soil and water technologies. The similarity of biochar with activated carbon predetermines this material as remediation tool which plays an important role in heavy metal immobilization and retention with a parallel reduction in the risk of ground water and food crop contamination. In all this processes the element-specific sorption behaviour of biochar creates new conditions for pollutant binding. Sorption interaction and separation of contaminants from soil solution or waste effluent can be affected by wide-ranging parameters. In detail, our study was based on batch-sorption comparisons of two biochars produced from wood chips and green waste residues. We observed that sorption efficiency of biochar for model bivalent heavy metals (Cd, Zn, Cu) can be influenced by equilibrium parameters such as pH, contact time, initial concentration of metal in reaction solutions, presence of surfactants and chemical modification by acid hydrolysis, esterification and methylation. The

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  18. Remediation/restoration of degraded soil I: Impact on soil chemical properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Characterizations of nutrient dynamics influenced by different management in eroded sites in the central Great Plains Region are critical. The objectives of this study were to evaluate the impact of tillage practices and N treatments on changes in soil nutrient constituents. The eroded site was loca...

  19. Enhanced electrokinetic (E/K) remediation on copper contaminated soil by CFW (carbonized foods waste).

    PubMed

    Han, Jung-Geun; Hong, Ki-Kwon; Kim, Young-Woong; Lee, Jong-Young

    2010-05-15

    The E/K remediation method is presented to purify low permeable contaminated soils due to Cu(2+), and carbonized foods waste (CFW) was used as a permeable reactive barrier (PRB) material. For adsorption and precipitation of the Cu(2+) in the PRB during its motion, PRB was installed in a zone of rapidly changing pH values. The adsorption efficiency of CFW used as PRB material was found to be 4-8 times more efficient than that of Zeolite. Throughout the experiment, a voltage slope of 1V/cm was implemented and acetic acid was injected on the anode to increase the remediation efficiency. The electrode exchange was executed to more completely remove precipitated heavy metals in the vicinity of the cathode. The majority of Cu(2+) was adsorbed or sedimented by CFW prior to the exchange of the electrode, and the remaining quantity of precipitated Cu(2+) on the cathode had decreased with an increase in the operating time. Experiments of seven cases with different E/K operating times were performed, and the average removal ratios were 53.4-84.6%. The removal efficiencies for the majority of cases increased proportionally with an increase in the operating time. After the experiments were completed, the adsorbed Cu(2+) on CFW was 75-150 mg. This means that the role of CFW as the material in PRB for remediating heavy metals was confirmed. The cost of energies needed to remove Cu(2+), CFW, and acetic acid are estimated at US$ 13.3-40/m(3). PMID:20080337

  20. Application of iron sulfide particles for groundwater and soil remediation: A review.

    PubMed

    Gong, Yanyan; Tang, Jingchun; Zhao, Dongye

    2016-02-01

    Rapid industrialization and urbanization have resulted in elevated concentrations of hazardous inorganic and organic contaminants in groundwater and soil, which has become a paramount concern to the environment and the public health. In recent years, iron sulfide (FeS), a major constituent of acid-volatile sulfides, has elicited extensive interests in environmental remediation due to its ubiquitous presence and high treatment efficiency in anoxic environment. This paper provides a comprehensive review on recent advances in: (1) synthesis of FeS particles (including nanoscale FeS); and (2) reactivity of FeS towards a variety of common environmental contaminants in groundwater and soil over extended periods of time, namely, heavy metals (Hg(II), Cu(II), Pb(II), and Cr(VI)), oxyanions (arsenite, arsenate, selenite, and selenate), radionuclides (e.g., uranium (U) and neptunium (Np)), chlorinated organic compounds (e.g., trichloroethane, trichloroethylene, and p-chloroaniline), nitroaromatic compounds, and polychlorinated biphenyls. Different physiochemical and biological methods for preparing FeS with desired particle size, structure, and surface properties are discussed. Reaction principles and removal effectiveness/constraints are discussed in details. Special attention is placed to the application of nanoscale FeS particles because of their unique properties, such as small particle size, large specific surface area, high surface reactivity, and soil deliverability in the subsurface. Moreover, current knowledge gaps and further research needs are identified. PMID:26707732

  1. Innovative fossil fuel fired vitrification technology for soil remediation. Phase 1

    SciTech Connect

    Not Available

    1994-01-01

    Vortec has successfully completed Phase 1 of the ``Innovative Fossil Fuel Fired Vitrification Technology for Soil Remediation`` program. The Combustion and Melting System (CMS) has processed 7000 pounds of material representative of contaminated soil that is found at DOE sites. The soil was spiked with Resource Conservation and Recovery Act (RCRA) metals surrogates, an organic contaminant, and a surrogate radionuclide. The samples taken during the tests confirmed that virtually all of the radionuclide was retained in the glass and that it did not leach to the environment-as confirmed by both ANS 16.1 and Toxicity Characteristic Leaching Procedure (TCLP) testing. The organic contaminant, anthracene, was destroyed during the test with a Destruction and Removal Efficiency (DRE) of at least 99.99%. RCRA metal surrogates, that were in the vitrified product, were retained and did not leach to the environment as confirmed by the TCLP testing. Semi-volatile RCRA metal surrogates were captured by the Air Pollution Control (APC) system, and data on the amount of metal oxide particulate and the chemical composition of the particulate were established for use in the Phase 2 APC subsystem design.

  2. [Effect of Cd on remediation of DDT contaminated soil using different laccase forms].

    PubMed

    Zhao, Yue-chun; Fu, Rong; Mo, Ce-huiz; Yi, Xiao-yun

    2008-08-01

    This study investigated the effect of Cd on remediation of DDT contaminated soil using free laccase and immobilized reversed micelles laccase. The results show: degradation rates of ingredients of DDT and total DDT reduced with increasing of Cd concentration, the higher percentage of components in total DDT, the greater impact of Cd on them. Degradation rates of different components were p, p'-DDT > p, p'-DDD > o,p'-DDT > p, p'-DDE. When Cd concentration was 0, 0.5, 1 and 2 mg x kg(-1), the responding degradation rates of DDTs were measured at 50.68%, 32.50%, 14.92% and 13.40%, respectively. Compared with free laccase, degradation rate of total DDT by immobilized reversed micelles laccase nearly increased by 20% in soil without Cd and 30% in soil with 0.5 mg x kg(-1) Cd, implying that immobilized reversed micelles laccase is more effective for DDT degradation than free laccase. PMID:18839595

  3. Application of rhizosphere interaction of hyperaccumulator Noccaea caerulescens to remediate cadmium-contaminated agricultural soil.

    PubMed

    Yang, Yong; Jiang, Rong-Feng; Wang, Wei; Li, Hua-Fen

    2011-10-01

    There is an urgent requirement for selecting appropriate technologies to solve food safety problems due to soil contamination. In this study, the hyperaccumulator Noccaea caerulescens and a high Cd accumulator pakchoi cultivar (Brassica rapa L. spp. Chinenesis cv.) were grown in a moderately Cd-contaminated soil with three planting systems (monocrop, inter-crop, and crop-rotation) and three growing durations (25, 50, and 75 days) to study the role of rhizosphere interaction of both species on the uptake of Cd. The Cd accumulations in the shoot of pakchoi were significantly reduced in the inter-crop treatment, also the decreased percentage increased with rhizosphere interaction between the two species. In the inter-crop systems of 75 days, the Cd concentration and amount in the shoot of pakchoi represented 54% and 83% reduction, respectively, while the total depletion of Cd decreased by approximate 19%. Although the Cd concentration and amount in the shoot of pakchoi were significantly reduced by 52% and 44%, respectively, in the crop-rotation treatment, the decreased percentage were markedly lower than in the inter-crop treatment. Therefore, the rhizosphere interaction of hyperaccumulator with non-hyperaccumulator may reduce the risk of vegetable contamination during making full use of or remediating the contaminated soil. PMID:21972514

  4. Harmful algal bloom removal and eutrophic water remediation by commercial nontoxic polyamine-co-polymeric ferric sulfate-modified soils.

    PubMed

    Dai, Guofei; Zhong, Jiayou; Song, Lirong; Guo, Chunjing; Gan, Nanqin; Wu, Zhenbin

    2015-07-01

    Harmful algal bloom has posed great threat to drinking water safety worldwide. In this study, soils were combined with commercial nontoxic polyamine poly(epichlorohydrin-dimethylamine) (PN) and polymeric ferric sulfate (PFS) to obtain PN-PFS soils for Microcystis removal and eutrophic water remediation under static laboratory conditions. High pH and temperature in water could enhance the function of PN-PFS soil. Algal removal efficiency increased as soil particle size decreased or modified soil dose increased. Other pollutants or chemicals (such as C, P, and organic matter) in eutrophic water could participate and promote algal removal by PN-PFS soil; these pollutants were also flocculated. During PN-PFS soil application in blooming field samples, the removal efficiency of blooming Microcystis cells exceeded 99 %, the cyanotoxin microcystins reduced by 57 %. Water parameters (as TP, TN, SS, and SPC) decreased by about 90 %. CODMn, PO4-P, and NH4-N also sharply decreased by >45 %. DO and ORP in water improved. Netting and bridging effects through electrostatic attraction and complexation reaction could be the two key mechanisms of Microcystis flocculation and pollutant purification. Considering the low cost of PN-PFS soil and its nontoxic effect on the environment, we proposed that this soil combination could be applied to remove cyanobacterial bloom and remediate eutrophic water in fields. PMID:25752635

  5. Remediation of toxic metal contaminated soil by washing with biodegradable aminopolycarboxylate chelants.

    PubMed

    Begum, Zinnat A; Rahman, Ismail M M; Tate, Yousuke; Sawai, Hikaru; Maki, Teruya; Hasegawa, Hiroshi

    2012-06-01

    Ex situ soil washing with synthetic extractants such as, aminopolycarboxylate chelants (APCs) is a viable treatment alternative for metal-contaminated site remediation. EDTA and its homologs are widely used among the APCs in the ex situ soil washing processes. These APCs are merely biodegradable and highly persistent in the aquatic environments leading to the post-use toxic effects. Therefore, an increasing interest is focused on the development and use of the eco-friendly APCs having better biodegradability and less environmental toxicity. The paper deals with the results from the lab-scale washing treatments of a real sample of metal-contaminated soil for the removal of the ecotoxic metal ions (Cd, Cu, Ni, Pb, and Zn) using five biodegradable APCs, namely [S,S]-ethylenediaminedisuccinic acid, imminodisuccinic acid, methylglycinediacetic acid, DL-2-(2-carboxymethyl) nitrilotriacetic acid (GLDA), and 3-hydroxy-2,2'-iminodisuccinic acid. The performance of those biodegradable APCs was evaluated for their interaction with the soil mineral constituents in terms of the solution pH and metal-chelant stability constants, and compared with that of EDTA. Speciation calculations were performed to identify the optimal conditions for the washing process in terms of the metal-chelant interactions as well as to understand the selectivity in the separation ability of the biodegradable chelants towards the metal ions. A linear relationship between the metal extraction capacity of the individual chelants towards each of the metal ions from the soil matrix and metal-chelant conditional stability constants for a solution pH greater than 6 was observed. Additional considerations were derived from the behavior of the major potentially interfering cations (Al, Ca, Fe, Mg, and Mn), and it was hypothesized that use of an excess of chelant may minimize the possible competition effects during the single-step washing treatments. Sequential extraction procedure was used to determine the

  6. Prediction of blood lead levels in children before and after remediation of soil samples in the upper Meza Valley, Slovenia.

    PubMed

    Jez, Erika; Lestan, Domen

    2015-10-15

    The Meza Valley, Slovenia, has been contaminated by Pb smelting, resulting in an epidemic of lead poisoning in childhood. The potential of remediation with EDTA soil washing to mitigate the risk from Pb poisoning was investigated by applying the Integrated Exposure Uptake Bio-kinetic (IEUBK) model. Soils from 79 locations were collected and the total and bio-accessible Pb concentrations were determined before and after extraction with 60 mmol kg(-1) EDTA. Extraction reduced the soil Pb concentration in towns of Mezica, Zerjav and Crna by 53, 67 and 62%, respectively, and the concentration of in vitro bio-accessible Pb in the simulated human gastric phase by 2.6-, 3.2- and 2.9-times, respectively. The predictions of the IEUBK model based on Pb contamination data were verified with data on blood Pb levels in children. The IEUBK model predicted that, after soil remediation, the number of locations at which the expected blood Pb level in children was higher than the stipulated 10 μg d L(-1) would decrease by 90, 38 and 91% in the towns of Mezica, Zerjav and Crna, respectively. The results confirmed the feasibility of soil washing with EDTA as an efficient remediation measure in Mezica and Crna and advice for soil capping/removal for the most polluted town of Zerjav. PMID:25917691

  7. EXTRACTION, RECOVERY, AND BIOSTABILITY OF EDTA FOR REMEDIATION OF HEAVY METAL-CONTAMINATED SOIL. (R825549C052)

    EPA Science Inventory

    Chelation removal of heavy metals from contaminated soil is seen as a viable remediation technique. A useful chelating agent should be strong, reusable, and biostable during metal extraction and recovery operations. This work tested the extraction, recovery, and biostability o...

  8. CURRENT AND FUTURE IN SITU TREATMENT TECHNIQUES FOR THE REMEDIATION OF HAZARDOUS SUBSTANCES IN SOIL, SEDIMENTS, AND GROUNDWATER

    EPA Science Inventory

    This is a presentation that will be given at the NATO Advanced Research Workshop on "Viable Methods of Soil and Water Pollution Monitoring, Protection, and Remediation" in Krakow, Poland on June 27 - July 1, 2005. The U.S. EPA Office of Research and Development (ORD) co...

  9. 75 FR 7591 - Guidance on Recommended Interim Preliminary Remediation Goals for Dioxin in Soil at CERCLA and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-22

    ... (75 FR 984), the deadline for the public to provide its comments was February 26, 2010. The purpose of... January 7, 2010 (75 FR 984), was for 50 days. Therefore, the new deadline will now be April 2, 2010. Dated... AGENCY RIN 2050-ZA05 Guidance on Recommended Interim Preliminary Remediation Goals for Dioxin in Soil...

  10. INTEGRATED DEMONSTRATION OF SURFACTANT-ENHANCED AQUIFER REMEDIATION WITH SURFACTANT RECOVERY AND REUSE

    EPA Science Inventory

    The demonstration site will be the base dry cleaning facility at Camp Lejeune, North Carolina. Conservative and partitioning tracer tests will be used in conjunction with conventional core and ground-water sampling to characterize the site with respect to DNAPL composition and d...

  11. ANALYSIS OF SOIL REMEDIATION REQUIREMENTS OF ABANDONED CENTRALIZED AND COMMERCIAL DRILLING

    SciTech Connect

    H. Seay Nance; Alan R. Dutton; Jerry Mullican

    2002-08-24

    During this reporting period our project focused on (1) review of case studies of remediation of centralized and commercial drilling fluid disposal (CCDD) sites in Texas, and (2) information transfer with preparation of a proceedings paper and a workshop/short course. Texas remediation of certain drilling-fluid disposal sites includes examples at CCDD sites as well as commercial oil reclamation sites and saltwater disposal sites that also disposed of drilling fluids in pits. Site investigations range from qualitative visual inspection and assessment to comprehensive hydrodynamic, chemical, and geophysical analyses of wastes and groundwater. A range of techniques has been used to evaluate waste material, soil, groundwater, and surface water for potential contamination with hydrocarbons, chemicals, saltwater, and naturally occurring radioactive materials (NORM). Most constituents of concern measured in these studies are below regulatory action levels and established guidelines. A proceedings paper summarizes results presented in this and previous semi-annual progress reports will be part of the Transactions of the Gulf Coast Association of Geological Societies (GCAGS). A technology transfer workshop also was prepared as part of that Annual Meeting of the GCAGS to be held in November 2002.

  12. TECHNICAL EVALUATION OF REMEDIATION TECHNOLOGIES FOR PLUTONIUM-CONTAMINATED SOILS AT THE NEVADA TEST SITE (NTS)

    SciTech Connect

    Steve Hoeffner

    2003-12-31

    The Clemson Environmental Technologies Laboratory (CETL) was contracted by the National Energy Technology Center to evaluate technologies that might be used to reduce the volume of plutonium-contaminated soil at the Nevada Test Site. The project has been systematically approached. A thorough review and summary was completed for: (1) The NTS soil geological, geochemical and physical characteristics; (2) The characteristics and chemical form of the plutonium that is in these soils; (3) Previous volume reduction technologies that have been attempted on the NTS soils; (4) Vendors with technology that may be applicable; and (5) Related needs at other DOE sites. Soils from the Nevada Test Site were collected and delivered to the CETL. Soils were characterized for Pu-239/240, Am-241 and gross alpha. In addition, wet sieving and the subsequent characterization were performed on soils before and after attrition scrubbing to determine the particle size distribution and the distribution of Pu-239/240 and gross alpha as a function of particle size. Sequential extraction was performed on untreated soil to provide information about how tightly bound the plutonium was to the soil. Magnetic separation was performed to determine if this could be useful as part of a treatment approach. Using the information obtained from these reviews, three vendors were selected to demonstration their volume reduction technologies at the CETL. Two of the three technologies, bioremediation and soil washing, met the performance criteria. Both were able to significantly reduce the concentration plutonium in the soil from around 1100 pCi/g to 200 pCi/g or less with a volume reduction of around 95%, well over the target 70%. These results are especially encouraging because they indicate significant improvement over that obtained in these earlier pilot and field studies. Additional studies are recommended.

  13. Perspectives of humic substances application in remediation of highly heavy metals contaminated soils in Kola Subarctic

    NASA Astrophysics Data System (ADS)

    Tregubova, Polina; Turbaevskaya, Valeria; Zakharenko, Andrey; Kadulin, Maksim; Smirnova, Irina; Stepanov, Andrey; Koptsik, Galina

    2016-04-01

    Northwestern part of Russia, the Kola Peninsula, is one of the most heavy metals (HM) contaminated areas in the northern hemisphere. The main polluters, mining-and-metallurgical integrated works "Pechenganikel" and "Severonikel", are surrounded by heavily damaged barren lands that require remediation. The main contaminating metals are Ni and Cu. Using of exogenous humic substances could be possible effective and cost-efficient solution of HM contamination problem. Rational application of humates (Na-K salts of humic acids) can result in improvement of soil properties, localization of contamination and decreasing bioavailability through binding HM in relatively immobile organic complexes. Our research aim was to evaluate the influence of increasing doses of different origin humates on i) basic properties of contaminated soils; ii) mobility and bioavailability of HMs; iii) vegetation state and chemistry. In summer 2013 a model field experiment was provided in natural conditions of the Kola Peninsula. We investigated the Al-Fe-humus abrazem, soil type that dominates in technogenic barren lands around the "Severonikel" work. These soils are strongly acid: pHH2O was 3.7-4.1; pHKCl was 3.4-4.0. The exchangeable acidity is low (0.8-1.6 cmol(+)/kg) due to the depletion of fine particles and organic matter, being the carriers of exchange positions. The abrazems of barrens had lost organic horizon. 12 sites were created in 1 km from the work. In those sites, except 2 controls, various amendments were added: i) two different by it's origin types of humates: peat-humates and coal-humates, the last were in concentrations 0.5% and 1%; ii) lime; iii) NPK-fertilizer; iv) biomates (organic degradable cover for saving warm and erosion protection). As a test-culture a grass mixture with predominance of Festuca rubra and Festuca ovina was sowed. As a result we concluded that humates of different origin have unequal influence on soil properties and cause decreasing as well as

  14. 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.

  15. Application of humic compounds for remediation of soils contaminated with heavy metals: the benefits and risks

    NASA Astrophysics Data System (ADS)

    Motuzova, Galina; Barsova, Natalia; Stepanov, Andrey; Kiseleva, Violetta; Kolchanova, Ksenia; Starkova, Irina; Karpukhin, Mikhail

    2015-04-01

    Applicability of humic compound (HC) "Extra" (potassium humate produced from coal) was studied to remediate soils contaminated with copper in model experiments. Field experiments were carried out in 10-litter plastic containers. The upper layer was prepared as a mixture of loam (pH=5.3), sand (pH=7.4) and peat(pH=5.5). It was underlain consequently by loam and gravel. To study water migration we installed lysimeters. The experiment was conducted in 3 variants: 1) control, 2) control+Cu, 3) control+Cu+HC. Copper was applied in the form of dry powder (CuSO4*5H2O) over the upper layer of the soil column in a concentration of copper equaling to 1000 mg/kg. Total concentration of copper was determined by ICP AAS, its free ions was measured with the help of ion-selective electrode. Humic compound was sprayed on the surface in liquid form. The vessels stayed outdoors from July to October 2014 with additional watering in dry periods. Analysis of lysimetric waters obtained from this model field experiment revealed significant impact of pH. Application of the humic compound produces almost 5 times higher content of soluble organic substances than in the variant without it, and in the first portions of lysimetric waters the difference is 20-fold. Generation of extra organic content in soluble form was accompanied by the 2-6 times increase of the water soluble copper yield. However the content of the free copper ions in lysimetric waters in case of addition of the potassium humate was negligible, because almost all copper was bounded with water-soluble organic substances. The copper content in water extract from the top layer of soil in the variant with HC was about 1 mg/l, that was 2 times higher than without HC. The content of water-soluble organic carbon in HC variant was 100 mg/L, and without HC was 10 times lower (10 mg/l). The water extract from soils enriched in HC was passed through a column filled with weakly basic anion exchange resin DEAE (Cl-form), the eluate was

  16. Development of Enhanced Remedial Techniques for Petroleum Fuel and Related Contaminants in Soil and Groundwater

    SciTech Connect

    Paul Fallgren

    2009-02-10

    Western Research Institute (WRI) in conjunction with Earth Tech and the U.S. Department of Energy (DOE) was to identify proper sites with soils and/or groundwater contaminated by petroleum constituents and MTBE. Biodegradation rates would have been quantitatively assessed in both laboratory and field tests to achieve the optimal destruction of contaminants of concern. WRI and Earth Tech identified a site contaminated with high concentrations of methanol associated with petroleum hydrocarbons. The site was assessed and a remediation project plan was prepared; however, the site was soon acquired by a new company. An agreement between Earth Tech, WRI, and the new site owners could not be reached; therefore, a work was performed to identify a new project site. Task 33 was terminated and the available funding was redeployed to other Tasks after receiving approval from the U.S. DOE task manager.

  17. Ultrasonic and mechanical soil washing processes for the remediation of heavy-metal-contaminated soil

    NASA Astrophysics Data System (ADS)

    Kim, Seulgi; Lee, Wontae; Son, Younggyu

    2016-07-01

    Ultrasonic/mechanical soil washing process was investigated and compared with ultrasonic process and mechanical process using a relatively large lab-scale sonoreactor. It was found that higher removal efficiencies were observed in the combined processes for 0.1 and 0.3 M HCl washing liquids. It was due to the combination effects of macroscale removal for the overall range of slurry by mechanical mixing and microscale removal for the limited zone of slurry by cavitational actions.

  18. Notes: Water Flow and Chemical Retardation in Soils: A Simple Effective Laboratory Demonstration.

    ERIC Educational Resources Information Center

    Bowman, R. S.; And Others

    1988-01-01

    Describes a laboratory demonstration that illustrates principles of miscible displacement and chemical retardation in soils. Discusses how the experimental apparatus can be constructed from readily available materials. (TW)

  19. Risk potentials for humans of original and remediated PAH-contaminated soils: application of biomarkers of effect.

    PubMed

    Roos, Peter H; Tschirbs, Sebastian; Pfeifer, Frank; Welge, Peter; Hack, Alfons; Wilhelm, Michael; Bolt, Hermann M

    2004-12-15

    Contaminated soils represent a potential health risk for the human population. Risk assessment for humans requires specific methods, which must reflect the peculiarities of human behaviour, physiology and biochemistry with respect to contaminant uptake and processing. Biomarkers of effect or exposure have become an appropriate tool. Organic pollutants influence the expression profile of cytochromes P450 (CYP), and CYP1A1 has been shown to be a suitable biomarker for polycyclic aromatic hydrocarbons (PAH). The latter are widely distributed in soils and constitute an important soil contamination. Upon intake of PAH-contaminated soils, CYP1A1 is induced in various organs of rats and minipigs. Increased CYP1A1-levels in lung, kidney and spleen, after oral soil intake, indicate that contaminants escape the primary duodenal and hepatic metabolism and reach further organs. Dose-response relationships reveal that induction effects are to be expected in children based on known exposure conditions. Generally, CYP1A1-induction does not correlate with results of toxicity tests with lower organisms, performed with the same soils. The organic carbon content is largely responsible for this discrepancy. It severely affects the toxicity of soil bound PAH for microorganisms, but obviously affects the mobilization efficiency for PAH in the gastro-intestinal tract of mammals to a minor extent. Soil remediation by different methods may result in a significant reduction of the PAH content and of toxicity. Ingestion of remediated soils by rats shows, however, that the induction potential for CYP1A1 is only slightly decreased after remediation. This means that the major inducing components resist biological remediation or soil washing and remain in the soil. Because data obtained with experimental animals form the guiding principle for in vitro tests to be developed, the suitability of the animal model used for extrapolations to humans has to be proven. Upon soil ingestion, minipigs show

  20. Demonstration test and evaluation of ultraviolet/ultraviolet catalyzed peroxide oxidation for groundwater remediation at Oak Ridge K-25 Site

    SciTech Connect

    1994-12-31

    In the UItraviolet/Ultraviolet Catalyzed Groundwater Remediation program, W.J. Schafer Associates, Inc. (WJSA) demonstrated, tested and evaluated a new ultraviolet (UV) lamp integrated with an existing commercial technology employing UV catalyzed peroxide oxidation to destroy organics in groundwater at an Oak Ridge K-25 site. The existing commercial technology is the perox-pure{trademark} process of Peroxidation Systems Incorporated (PSI) that employs standard UV lamp technology to catalyze H{sub 2}O{sub 2} into OH radicals, which attack many organic molecules. In comparison to classical technologies for remediation of groundwater contaminated with organics, the perox-pure{trademark} process not only is cost effective but also reduces contaminants to harmless by-products instead of transferring the contaminants from one medium to another (such as in activated carbon or air stripping). Although the perox-pure{trademark} process is cost effective against many organics, it is not effective for some organic contaminants of interest to DOE such as TCA, which has the highest concentration of the organics at the K-25 test site. Contaminants such as TCA are treated more readily by direct photolysis using short wavelength UV light. WJSA has been developing a unique UV lamp which is very efficient in the short UV wavelength region. Consequently, combining this UV lamp with the perox-pure{trademark} process results in a means for treating essentially all organic contaminants. In the program reported here, the new UV lamp lifetime was improved and the lamp integrated into a PSI demonstration trailer. Even though this UV lamp operated at less than optimum power and UV efficiency, the destruction rate for the TCA was more than double that of the commercial unit. An optimized UV lamp may double again the destruction rate; i.e., a factor of four greater than the commercial system.

  1. An Exercise to Demonstrate Soil Microbial Diversity in Introductory Environmental Science Classrooms

    ERIC Educational Resources Information Center

    Yarwood, Stephanie A.; Sulzman, Elizabeth W.

    2008-01-01

    High diversity of microorganisms in the soil matrix has been the focus of extensive research in the fields of soil biology and microbial ecology, and is a key concept that students in the environmental or biological sciences should understand. Two activities to demonstrate diversity and highlight the challenges faced in studying soil microbial…

  2. SITE DEMONSTRATION BULLETIN: SOIL RECYCLING TREATMENT TRAIN - THE TORONTO HARBOUR COMMISSIONERS

    EPA Science Inventory

    The Toronto Harbour Commissioners (THC) have developed a soil treatment train designed to treat inorganic and organic contaminants in soils. THC has conducted a large-scale demonstration of these technologies in an attempt to establish that contaminated soils at the Toronto Port...

  3. Evaluation of the effectiveness of sepiolite, bentonite, and phosphate amendments on the stabilization remediation of cadmium-contaminated soils.

    PubMed

    Sun, Yuebing; Sun, Guohong; Xu, Yingming; Liu, Weitao; Liang, Xuefeng; Wang, Lin

    2016-01-15

    A pot trial was conducted to assess the effectiveness of sepiolite, bentonite, and phosphate on the immobilization remediation of cadmium (Cd)-contaminated soils using a set of variables, namely, physiological traits, sequential extraction procedure, plant growth and Cd concentration, and soil enzymatic activities and microbial population. Results showed that superoxide dismutase and peroxidase activities in the leaves of Oryza sativa L. and catalase activities in soils were stimulated after applying the amendments. However, soluble protein contents in leaves and urease and invertase activities in soils were reduced from 7.1% to 31.7%, 1.0%-23.3%, and 21.1%-62.5%, respectively, compared with the control. Results of the sequence extraction procedures revealed that the exchangeable fraction of Cd in soils was mostly converted into carbonated-associated forms. The water soluble plus exchangeable fraction (SE) of Cd in soil decreased when treated with single and compound materials of sepiolite, bentonite and phosphate, which resulted in 13.2%-69.2% reduction compared with that of CK (control test). The amendments led to decreased Cd concentrations in roots, stems, leaves, brown rice, and rice hull by 16.2%-54.5%, 16.6%-42.8%, 19.6%-59.6%, 5.0%-68.2%, and 6.2%-20.4%, respectively. Higher bacterial and actinomycete amount indicated that remediation measures improved soil environmental quality. Composite amendments could be more efficiently used for the stabilization remediation of Cd contaminated soils with low Cd uptake and translocation in the plants and available contents of Cd in soil. PMID:26513318

  4. The transport behavior of As, Cu, Pb, and Zn during electrokinetic remediation of a contaminated soil using electrolyte conditioning.

    PubMed

    Yang, Jung-Seok; Kwon, Man Jae; Choi, Jaeyoung; Baek, Kitae; O'Loughlin, Edward J

    2014-12-01

    Electrokinetic remediation (also known as electrokinetics) is a promising technology for removing metals from fine-grained soils. However, few studies have been conducted regarding the transport behavior of multi-metals during electrokinetics. We investigated the transport of As, Cu, Pb, and Zn from soils during electrokinetics, the metal fractionation before and after electrokinetics, the relationships between metal transport and fractionation, and the effects of electrolyte conditioning. The main transport mechanisms of the metals were electroosmosis and electromigration during the first two weeks and electromigration during the following weeks. The direction of electroosmotic flow was from the anode to the cathode, and the metals in the dissolved and reducible-oxides fractions were transported to the anode or cathode by electromigration according to the chemical speciation of the metal ions in the pore water. Moreover, a portion of the metals that were initially in the residual fraction transitioned to the reducible and soluble fractions during electrokinetic treatment. However, this alteration was slow and resulted in decreasing metal removal rates as the electrokinetic treatment progressed. In addition, the use of NaOH, H3PO4, and Na2SO4 as electrolytes resulted in conditions that favored the precipitation of metal hydroxides, phosphates, and sulfates in the soil. These results demonstrated that metal removal was affected by the initial metal fractionation, metal speciation in the pore solution, and the physical-chemical parameters of the electrolytes, such as pH and electrolyte composition. Therefore, the treatment time, use of chemicals, and energy consumption could be reduced by optimizing pretreatment and by choosing appropriate electrolytes for the target metals. PMID:24972074

  5. Efficient remediation of PAH-metal co-contaminated soil using microbial-plant combination: A greenhouse study.

    PubMed

    Chen, Fu; Tan, Min; Ma, Jing; Zhang, Shaoliang; Li, Gang; Qu, Junfeng

    2016-01-25

    A 2-year greenhouse study was conducted to remediate an actual wastewater-irrigated soil co-contaminated with polycyclic aromatic hydrocarbons (PAHs) and heavy metals (Cd and Zn). The remediation methods included microbial remediation, phytoremediation, and microbe-assisted phytoremediation. The maximum PAH removal (96.4%), PAH mineralization, and metal phytoextraction (36.1% Cd and 12.7% Zn) were obtained by interplanting ryegrass with Seduce alfredii with regular re-inoculation with Microbacterium sp. KL5 and Candida tropicalis C10 in the co-contaminated soil. The plants shoots were harvested at a 4-month interval. After 2 years, the concentrations of 16 individual PAHs were reduced to below the limit of Chinese soil quality standard for agricultural use (grade II, pH 6.5-7.5), and the metal concentrations in ryegrass shoots were below the Chinese national limit for animal feeds (GB13078-2001). The exogenous microbes gradually disappeared with time, and thus a 2-month re-inoculation interval was applied for a purpose to maintain high cell density and activity of the inoculants. KL5 introduction increased soil enzyme activity, plant growth, PAH removal and metal phytoextraction, while C10 promoted soil enzyme activity and removal of high-molecular-weight PAHs. Interplanting with S. alfredii reduced metal concentrations in ryegrass tissues. Ryegrass showed stronger rhizosphere effects than S. alfredii did. PMID:26476312

  6. Environmental materials for remediation of soils contaminated with lead and cadmium using maize (Zea mays L.) growth as a bioindicator.

    PubMed

    Shi, Yu; Huang, Zhanbin; Liu, Xiujie; Imran, Suheryani; Peng, Licheng; Dai, Rongji; Deng, Yulin

    2016-04-01

    Heavy metal pollution is a severe environmental problem. Remediation of contaminated soils can be accomplished using environmental materials that are low cost and environmentally friendly. We evaluated the individual and combination effects of humic acid (HA), super absorbent polymer (SAP), zeolite (ZE), and fly ash composites (FC) on immobilization of lead (Pb) and cadmium (Cd) in contaminated soils. We also investigated long-term practical approaches for remediation of heavy metal pollution in soil. The biochemical and morphological properties of maize (Zea mays L.) were selected as biomarkers to assess the effects of environmental materials on heavy metal immobilization. The results showed that addition of test materials to soil effectively reduced heavy metal accumulation in maize foliage, improving chlorophyll levels, plant growth, and antioxidant enzyme activity. The test materials reduced heavy metal injury to maize throughout the growth period. A synergistic effect from combinations of different materials on immobilization of Pb and Cd was determined based on the reduction of morphological and biochemical injuries to maize. The combination of zeolite and humic acid was especially effective. Treatment with a combination of HA + SAP + ZE + FC was superior for remediation of soils contaminated with high levels of Pb and Cd. PMID:26604199

  7. Kinetics as a tool to assess the immobilization of soil trace metals by binding phase amendments for in situ remediation purposes.

    PubMed

    Varrault, Gilles; Bermond, Alain

    2011-08-30

    Many soil remediation techniques consist in decreasing the mobility of trace metals by means of adding trace metal binding phases. For this study, whose aim is to assess the efficiency of soil remediation method by binding phase amendment, a kinetic fractionation method that provides the labile and slowly labile trace metal amounts in soil has been introduced. Manganese oxides (vernadite) and insolubilized humic acids (IHA) have been used as binding phases for the remediation of four heavily polluted soils. Vernadite amendments are effective for lead and cadmium remediation, whereas IHA amendments are only effective for copper remediation. In most cases, the labile metal fractions decrease dramatically in amended soils (up to 50%); on the other hand, the amounts of total extracted metal near the point of thermodynamic equilibrium often show no significant difference between the amended soil and the control soil. These results highlight the utility of kinetic fractionation in assessing the efficiency of soil remediation techniques and, more generally, in evaluating trace metal mobility in soils and its potential advantages compared to extraction schemes performed under equilibrium conditions. In the future, this kinetic method could be considerably simplified so as to consume much less time allowing its routine use. PMID:21708424

  8. Remediation and Safe Production of cd Contaminated Soil Via Multiple Cropping Hyperaccumulator Solanum nigrum L. and Low Accumulation Chinese Cabbage.

    PubMed

    Niu, Mingfen; Wei, Shuhe; Bai, Jiayi; Wang, Siqi; Ji, Dandan

    2015-01-01

    Multiple crop experiment of hyperaccumulator Solanum nigrum L. with low accumulation Chinese cabbage Fenyuanxin 3 were conducted in a cadmium (Cd) contaminated vegetable field. In the first round, the average removal rate of S. nigrum to Cd was about 10% without assisted phytoextraction reagent addition for the top soil (0-20 cm) with Cd concentration at 0.53-0.97 mg kg(-1) after its grew 90 days. As for assisted phytoextraction reagent added plots, efficiency of Cd remediation might reach at 20%. However, in the second round, Cd concentration in Chinese cabbage was edible, even in the plots with assisted phytoextraction reagent added. Thus, multiple cropping hyperaccumulator with low accumulation crop could normally remediate contaminated soil and produce crop (obtain economic benefit) in one year, which may be one practical pathway of phytoremediating heavy metal contaminated soil in the future. PMID:25976879

  9. "PRACTICAL PHYTOEXTRACTION OF SOIL CD"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selection of appropriate methods for remediation of soil metals requires careful evaluation of whether the soil contaminant is sufficiently bioavailable or phytoavailable to require remediation. Extensive study of soil Cd risk has recently demonstrated that the high prevalence of renal tubular dysfu...

  10. 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.

  11. Innovative technology demonstrations

    SciTech Connect

    Anderson, D.B.; Hartley, J.N.; Luttrell, S.P.

    1992-04-01

    Currently, several innovative technologies are being demonstrated at Tinker Air Force Base (TAFB) to address specific problems associated with remediating two contaminated test sites at the base. Cone penetrometer testing (CPT) is a form of testing that can rapidly characterize a site. This technology was selected to evaluate its applicability in the tight clay soils and consolidated sandstone sediments found at TAFB. Directionally drilled horizontal wells have been successfully installed at the US Department of Energy's (DOE) Savannah River Site to test new methods of in situ remediation of soils and ground water. This emerging technology was selected as a method that may be effective in accessing contamination beneath Building 3001 without disrupting the mission of the building, and in enhancing the extraction of contamination both in ground water and in soil. A soil gas extraction (SGE) demonstration, also known as soil vapor extraction, will evaluate the effectiveness of SGE in remediating fuels and TCE contamination contained in the tight clay soil formations surrounding the abandoned underground fuel storage vault located at the SW Tanks Site. In situ sensors have recently received much acclaim as a technology that can be effective in remediating hazardous waste sites. Sensors can be useful for determining real-time, in situ contaminant concentrations during the remediation process for performance monitoring and in providing feedback for controlling the remediation process. A demonstration of two in situ sensor systems capable of providing real-time data on contamination levels will be conducted and evaluated concurrently with the SGE demonstration activities. Following the SGE demonstration, the SGE system and SW Tanks test site will be modified to demonstrate bioremediation as an effective means of degrading the remaining contaminants in situ.

  12. Innovative technology demonstrations

    SciTech Connect

    Anderson, D.B.; Hartley, J.N.; Luttrell, S.P.

    1992-04-01

    Currently, several innovative technologies are being demonstrated at Tinker Air Force Base (TAFB) to address specific problems associated with remediating two contaminated test sites at the base. Cone penetrometer testing (CPT) is a form of testing that can rapidly characterize a site. This technology was selected to evaluate its applicability in the tight clay soils and consolidated sandstone sediments found at TAFB. Directionally drilled horizontal wells have been successfully installed at the US Department of Energy`s (DOE) Savannah River Site to test new methods of in situ remediation of soils and ground water. This emerging technology was selected as a method that may be effective in accessing contamination beneath Building 3001 without disrupting the mission of the building, and in enhancing the extraction of contamination both in ground water and in soil. A soil gas extraction (SGE) demonstration, also known as soil vapor extraction, will evaluate the effectiveness of SGE in remediating fuels and TCE contamination contained in the tight clay soil formations surrounding the abandoned underground fuel storage vault located at the SW Tanks Site. In situ sensors have recently received much acclaim as a technology that can be effective in remediating hazardous waste sites. Sensors can be useful for determining real-time, in situ contaminant concentrations during the remediation process for performance monitoring and in providing feedback for controlling the remediation process. A demonstration of two in situ sensor systems capable of providing real-time data on contamination levels will be conducted and evaluated concurrently with the SGE demonstration activities. Following the SGE demonstration, the SGE system and SW Tanks test site will be modified to demonstrate bioremediation as an effective means of degrading the remaining contaminants in situ.

  13. An overview of preparation and applications of stabilized zero-valent iron nanoparticles for soil and groundwater remediation.

    PubMed

    Zhao, Xiao; Liu, Wen; Cai, Zhengqing; Han, Bing; Qian, Tianwei; Zhao, Dongye

    2016-09-01

    Nano-scale zero-valent iron (nZVI) is one of the most intensively studied materials for environmental cleanup uses over the past 20 years or so. Freshly prepared nZVI is highly reactive due to its high specific surface area and strong reducing power. Over years, the classic borohydride reduction method for preparing nZVI has been modified by use of various stabilizers or surface modifiers to acquire more stable and soil deliverable nZVI for treatment of different organic and inorganic contaminants in water and soil. While most studies have been focused on testing nZVI for water treatment, the greater potential or advantage of nZVI appears to be for in situ remediation of contaminated soil and groundwater by directly delivering stabilized nZVI into the contaminated subsurface as it was proposed from the beginning. Compared to conventional remediation practices, the in situ remediation technique using stabilized nZVI offers some unique advantages. This work provides an update on the latest development of stabilized nZVI for various environmental cleanup uses, and overviews the evolution and environmental applications of stabilized nZVI. Commonly used stabilizers are compared and the stabilizing mechanisms are discussed. The effectiveness and constraints of the nZVI-based in situ remediation technology are summarized. This review also reveals some critical knowledge gaps and research needs, such as interactions between delivered nZVI and the local biogeochemical conditions. PMID:27206054

  14. [Demonstration of Yersinia pseudotuberculosis in in cultivated soils].

    PubMed

    Barre, N; Louzis, C; Treignier, M; Dubois-Darnaudpeys, A

    1977-06-13

    The bacteriological analysis of 37 pools of cultivated soils collected in a limited area in the Parisian district permits the isolation of 14 strains of Y. pseudotuberculosis: 9 strains are of serotype II, 3 of serotype I, 1 of serotype III, and of serotype IV. This diversity contrasts with the prevalence of serotype I in infections of man and animals and the scarcity of type III and IV in these species. The abundance of our isolates is in favour of a large distribution of the germ in this substratum, which can be considered as a potential contamination source. PMID:408041

  15. Remediation System Design Optimization: Field Demonstration at the Umatilla Army Deport

    NASA Astrophysics Data System (ADS)

    Zheng, C.; Wang, P. P.

    2002-05-01

    Since the early 1980s, many researchers have shown that the simulation-optimization (S/O) approach is superior to the traditional trial-and-error method for designing cost-effective groundwater pump-and-treat systems. However, the application of the S/O approach to real field problems has remained limited. This paper describes the application of a new general simulation-optimization code to optimize an existing pump-and-treat system at the Umatilla Army Depot in Oregon, as part of a field demonstration project supported by the Environmental Security Technology Certification Program (ESTCP). Two optimization formulations were developed to minimize the total capital and operational costs under the current and possibly expanded treatment plant capacities. A third formulation was developed to minimize the total contaminant mass of RDX and TNT remaining in the shallow aquifer by the end of the project duration. For the first two formulations, this study produced an optimal pumping strategy that would achieve the cleanup goal in 4 years with a total cost of 1.66 million US dollars in net present value. For comparison, the existing design in operation was calculated to require 17 years for cleanup with a total cost of 3.83 million US dollars in net present value. Thus, the optimal pumping strategy represents a reduction of 13 years in cleanup time and a reduction of 56.6 percent in the expected total expenditure. For the third formulation, this study identified an optimal dynamic pumping strategy that would reduce the total mass remaining in the shallow aquifer by 89.5 percent compared with that calculated for the existing design. In spite of their intensive computational requirements, this study shows that the global optimization techniques including tabu search and genetic algorithms can be applied successfully to large-scale field problems involving multiple contaminants and complex hydrogeological conditions.

  16. Remediation of polycyclic aromatic hydrocarbon and metal-contaminated soil by successive methyl-β-cyclodextrin-enhanced soil washing-microbial augmentation: a laboratory evaluation.

    PubMed

    Sun, Mingming; Luo, Yongming; Teng, Ying; Jia, Zhongjun; Li, Zhengao; Deng, Shiping

    2013-02-01

    Polycyclic aromatic hydrocarbon (PAH) and metal-polluted sites caused by abandoned coking plants are receiving wide attention. To address the associated environmental concerns, innovative remediation technologies are urgently needed. This study was initiated to investigate the feasibility of a cleanup strategy that employed an initial phase, using methyl-β-cyclodextrin (MCD) solution to enhance ex situ soil washing for extracting PAHs and metals simultaneously, followed by the addition of PAH-degrading bacteria (Paracoccus sp. strain HPD-2) and supplemental nutrients to treat the residual soil-bound PAHs. Elevated temperature (50 °C) in combination with ultrasonication (35 kHz, 30 min) at 100 g MCD L(-1) was effective in extracting PAHs and metals to assist soil washing; 93 % of total PAHs, 72 % of Cd, 78 % of Ni, 93 % of Zn, 84 % of Cr, and 68 % of Pb were removed from soil after three successive washing cycles. Treating the residual soil-bound PAHs for 20 weeks led to maximum biodegradation rates of 34, 45, 36, and 32 % of the remaining total PAHs, 3-ring PAHs, 4-ring PAHs, and 5(+6)-ring PAHs after washing procedure, respectively. Based on BIOLOG Ecoplate assay, the combined treatment at least partially restored microbiological functions in the contaminated soil. The ex situ cleanup strategy through MCD-enhanced soil washing followed by microbial augmentation can be effective in remediating PAH and metal-contaminated soil. PMID:22802116

  17. Fenton oxidation to remediate PAHs in contaminated soils: A critical review of major limitations and counter-strategies.

    PubMed

    Usman, M; Hanna, K; Haderlein, S

    2016-11-01

    Fenton oxidation constitutes a viable remediation strategy to remove polycyclic aromatic hydrocarbons (PAHs) in contaminated soils. This review is intended to illustrate major limitations associated with this process like acidification, PAH unavailability, and deterioration of soil quality along with associated factors, followed by a critical description of various developments to overcome these constraints. Considering the limitation that its optimal pH is around 3, traditional Fenton treatment could be costly, impractical in soil due to the high buffering capacity of soils and associated hazardous effects. Use of various chelating agents (organic or inorganic) allowed oxidation at circumneutral pH but factors like higher oxidant demand, cost and toxicity should be considered. Another alternative is the use of iron minerals that can catalyze Fenton-like oxidation over a wide range of pH, but mobility of these particles in soils (i.e. saturated and unsaturated zones) should be investigated prior to in-situ applications. The PAH-unavailability is the crucial limitation hindering their effective degradation. Research data is compiled describing various strategies to address this issue like the use of availability enhancement agents, extraction or thermal pretreatment. Last section of this review is devoted to describe the effects of various developments in Fenton treatment onto soil quality and native microbiota. Finally, research gaps are discussed to suggest future directions in context of applying Fenton oxidation to remediate contaminated soils. PMID:27341118

  18. Enhanced-electrokinetic remediation of copper-pyrene co-contaminated soil with different oxidants and pH control.

    PubMed

    Cang, Long; Fan, Guang-Ping; Zhou, Dong-Mei; Wang, Quan-Ying

    2013-02-01

    Electrokinetic (EK) remediation has potential to simultaneously remove heavy metals and organic compounds from soil, but the removal percent of these pollutants is very low in general if no enhancing treatment is applied. This study developed a new enhanced-EK remediation technology to decontaminate a heavy metal-organic compound co-contaminated soil by applying different oxidants and pH control. A red soil was used as a model clayed soil, and was spiked with pyrene and Cu at about 500 mg kg(-1) for both to simulate real situation. Bench-scale EK experiments were performed using four oxidants (H(2)O(2), NaClO, KMnO(4), and Na(2)S(2)O(8)) and controlling electrolyte pH at 3.5 or 10. After the treatments with 1.0 V cm(-1) of voltage gradient for 335 h, soil pH, electrical conductivity, and the concentrations and chemical fractionations of soil pyrene and Cu were analyzed. The results showed that there was significant migration of pyrene and Cu from the soil, and the removal percent of soil pyrene and Cu varied in the range of 30-52% and 8-94%, respectively. Low pH favoured the migration of soil Cu, while KMnO(4) was the best one for the degradation of pyrene among the tested oxidants, although it unfortunately prevented the migration of soil Cu by forming Cu oxide. Application of Na(2)S(2)O(8) and to control the catholyte pH at 3.5 were found to be the best operation conditions for decontaminating the Cu-pyrene co-contaminated soil. PMID:23177009

  19. Removal of organic pollutants and heavy metals in soils by electrokinetic remediation.

    PubMed

    Ricart, M T; Pazos, M; Gouveia, S; Cameselle, C; Sanroman, M A

    2008-07-01

    In this work, the feasibility of electrokinetic remediation for the restoration of polluted soil with organic and inorganic compounds had been development and evaluated using a model soil sample. The model soil was prepared with kaolinite clay artificially polluted in the laboratory with chromium and an azo dye: Reactive Black 5 (RB5). The electromigration of Cr in a spiked kaolinite sample was studied in alkaline conditions. Despite of the high pH registered in the kaolinite sample (around pH 9.5), Cr migrated towards the cathode and it was accumulated in the cathode chamber forming a white precipitate. The removal was not complete, and 23% of the initial Cr was retained into the kaolinite sample close to the cathode side. The azo dye RB5 could be effectively removed from kaolinite by electrokinetics and the complete cleanup of the kaolinite could be achieved in alkaline environment. In this condition, RB5 formed an anion that migrated towards the anode where it was accumulated and quickly degraded upon the electrode surface. The electrokinetic treatment of a kaolinite sample polluted with both Cr and RB5 yielded very good results. The removal of Cr was improved compared to the experiment where Cr was the only pollutant, and RB5 reached a removal as high as 95%. RB5 was removed by electromigration towards the anode, where the dye was degraded upon the surface of the electrode by electrochemical oxidation. Cr was transported towards the cathode by electromigration and electroosmosis. It is supposed that the interaction among RB5 and Cr into the kaolinite sample prevented premature precipitation and allow Cr to migrate and concentrate in the cathode chamber. PMID:18569297

  20. Study on 3D surfactant assisted electrokinetic remediation of 1,2,4-trichlorobenzene in low permeability soil

    NASA Astrophysics Data System (ADS)

    Qiao, W.; Ye, S.; Wu, J.

    2014-12-01

    Electrickinetic(EK) is a promising remediation technology because of its capability to remediate soils with low permeability. It has been used for heavy metals and organic pollutant(OPs) contaminated soils. As the most OPs are poor solubility and strong sorption capacity, combined EK technology is usually used, for example, EK combined with surfactants. Numerous combined EK tests are done in one-dimension(1D) column, however, it is proved that there is a big gap between 1D tests and field application. The objectives of this study are to investigate the remediation efficiency and EK behavior of 1,2,4-trichlorobenzene(1,2,4-TCB) contaminated clay enhanced by surfactants in a three-dimension reactor with 28cm length×15cm width×16cm height. 1,2,4-TCB was one of the main contaminants at a field site in Nanjing, China, where the polluted soils are clay. Soil filled in EK cell was divided into six layers in depth, and each layer was divided into six parts in length and three parts in width. There were 108 specimens in total which realized 3D monitoring the effects of EK. Triton X-100(Exp1) and Tween80(Exp2) dissolved in NaCO3/NaHCO3 buffer respectively, were used as the anode purging solution. The distributions of soil pH and water content showed that the buffer was sufficient to neutralize H+ produced at anode and the direction of electroosmotic flow(EOF) remained constant. Exp2 generated a higher EOF than Exp1, but remediation efficiencies were not satisfactory so far. The concentration of 1,2,4-TCB in soil reached a peak and nadir in the normalized distances of 0.75 and 0.9 from cathode after 5 days, respectively. The 1,2,4-TCB concentration in the peak was almost twice as much as the initial concentration. It suggested that 1,2,4-TCB was desorbed from soil by surfactants and was transported from anode to cathode by EOF, which proved the capability of EK with surfactants to move 1,2,4-TCB in clay. The concentration of 1,2,4-TCB in the normalized distances of 0

  1. Remediation of lead-contaminated soil with EDTA: Batch and column studies

    SciTech Connect

    Heil, D.M.; Samani, Z.; Hanson, A.T.; Hu, S.; Rudd, B.

    1996-12-31

    Chelate extraction using ethylenediaminetetraacetic acid (EDTA) and other chelates has been demonstrated to be an effective method of removal of Pb from many contaminated soils. However, column leaching of Pb from alkaline soils with EDTA has been problematic due to extremely low soil permeability. The purpose of this study was to determine the effect of the addition of KOH and Ca(Cl){sub 2} to K{sub 2}H{sub 2}-EDTA extraction solution on Pb removal and hydraulic conductivity. A Pb-contaminated soil was sampled from an abandoned lead-acid battery recycling facility. Both batch shaker extractions and column leaching experiments were completed using five different EDTA extract solutions. Addition of Ca(Cl){sub 2} only to K{sub 2}H{sub 2}-EDTA did not change the amount of Pb removed by batch extraction, and Pb solubility was only slightly decreased by the addition of both Ca(Cl){sub 2} and KOH. Lead solubility was observed to decrease as pH was increased by the addition of KOH. The amount of time required to leach 6.0 l of extraction solution through the soil columns varied from 2 to 33 days. The addition of Ca(Cl){sub 2} and/or KOH resulted in increased soil hydraulic conductivity. However, Pb removal was diminished with the addition of Ca(Cl){sub 2} and KOH because of decreased Pb solubility and also a shorter residence time of the extract solution in the column. The hydraulic conductivity was related to residual calcium carbonate content, suggesting that dissolution of CaCO{sub 3} and subsequent production of CO{sub 2} gas in soil pores was partially responsible for the observed reductions in soil permeability.

  2. Innovative technology demonstrations

    SciTech Connect

    Anderson, D.B.; Luttrell, S.P. ); Hartley, J.N. . Environmental Management Operations); Hinchee, R. )

    1992-08-01

    Environmental Management Operations (EMO) is conducting an Innovative Technology Demonstration Program for Tinker Air Force Base (TAFB). Several innovative technologies are being demonstrated to address specific problems associated with remediating two contaminated test sites at the base. Cone penetrometer testing (CPT) is a form of testing that can rapidly characterize a site. This technology was selected to evaluate its applicability in the tight clay soils and consolidated sandstone sediments found at TAFB. Directionally drilled horizontal wells was selected as a method that may be effective in accessing contamination beneath Building 3001 without disrupting the mission of the building, and in enhancing the extraction of contamination both in ground water and in soil. A soil gas extraction (SGE) demonstration, also known as soil vapor extraction, will evaluate the effectiveness of SGE in remediating fuels and TCE contamination contained in the tight clay soil formations surrounding the abandoned underground fuel storage vault located at the SW Tanks Site. In situ sensors have recently received much acclaim as a technology that can be effective in remediating hazardous waste sites. Sensors can be useful for determining real-time, in situ contaminant concentrations during the remediation process for performance monitoring and in providing feedback for controlling the remediation process. Following the SGE demonstration, the SGE system and SW Tanks test site will be modified to demonstrate bioremediation as an effective means of degrading the remaining contaminants in situ. The bioremediation demonstration will evaluate a bioventing process in which the naturally occurring consortium of soil bacteria will be stimulated to aerobically degrade soil contaminants, including fuel and TCE, in situ.

  3. TECHNICAL EVALUATION OF SOIL REMEDIATION ALTERNATIVES AT THE BUILDING 812 OPERABLE UNIT, LAWRENCE LIVERMORE NATIONAL LABORATORY SITE 300

    SciTech Connect

    Eddy-Dilek, C.; Miles, D.; Abitz, R.

    2009-08-14

    The Department of Energy Livermore Site Office requested a technical review of remedial alternatives proposed for the Building 812 Operable Unit, Site 300 at the Lawrence Livermore National Laboratory. The team visited the site and reviewed the alternatives proposed for soil remediation in the draft RI/FS and made the following observations and recommendations. Based on the current information available for the site, the team did not identify a single technology that would be cost effective and/or ecologically sound to remediate DU contamination at Building 812 to current remedial goals. Soil washing is not a viable alternative and should not be considered at the site unless final remediation levels can be negotiated to significantly higher levels. This recommendation is based on the results of soil washing treatability studies at Fernald and Ashtabula that suggest that the technology would only be effective to address final remediation levels higher than 50 pCi/g. The technical review team identified four areas of technical uncertainty that should be resolved before the final selection of a preferred remedial strategy is made. Areas of significant technical uncertainty that should be addressed include: (1) Better delineation of the spatial distribution of surface contamination and the vertical distribution of subsurface contamination in the area of the firing table and associated alluvial deposits; (2) Chemical and physical characterization of residual depleted uranium (DU) at the site; (3) Determination of actual contaminant concentrations in air particulates to support risk modeling; and (4) More realistic estimation of cost for remedial alternatives, including soil washing, that were derived primarily from vendor estimates. Instead of conducting the planned soil washing treatability study, the team recommends that the site consider a new phased approach that combines additional characterization approaches and technologies to address the technical uncertainty in

  4. Implications of soil mixing for NAPL source zone remediation: Column studies and modeling of field-scale systems

    NASA Astrophysics Data System (ADS)

    Olson, Mitchell R.; Sale, Tom C.

    2015-06-01

    Soil remediation is often inhibited by subsurface heterogeneity, which constrains contaminant/reagent contact. Use of soil mixing techniques for reagent delivery provides a means to overcome contaminant/reagent contact limitations. Furthermore, soil mixing reduces the permeability of treated soils, thus extending the time for reactions to proceed. This paper describes research conducted to evaluate implications of soil mixing on remediation of non-aqueous phase liquid (NAPL) source zones. The research consisted of column studies and subsequent modeling of field-scale systems. For column studies, clean influent water was flushed through columns containing homogenized soils, granular zero valent iron (ZVI), and trichloroethene (TCE) NAPL. Within the columns, NAPL depletion occurred due to dissolution, followed by either column-effluent discharge or ZVI-mediated degradation. Complete removal of TCE NAPL from the columns occurred in 6-8 pore volumes of flow. However, most of the TCE (> 96%) was discharged in the column effluent; less than 4% of TCE was degraded. The low fraction of TCE degraded is attributed to the short hydraulic residence time (< 4 days) in the columns. Subsequently, modeling was conducted to scale up column results. By scaling up to field-relevant system sizes (> 10 m) and reducing permeability by one-or-more orders of magnitude, the residence time could be greatly extended, potentially for periods of years to decades. Model output indicates that the fraction of TCE degraded can be increased to > 99.9%, given typical post-mixing soil permeability values. These results suggest that remediation performance can be greatly enhanced by combining contaminant degradation with an extended residence time.

  5. In situ remediation of metal-contaminated soils with organic amendments: role of humic acids in copper bioavailability.

    PubMed

    Soler-Rovira, Pedro; Madejón, Engracia; Madejón, Paula; Plaza, César

    2010-05-01

    The purposes of this study were to determine the Cu(II) binding behavior of humic acids (HAs) isolated from biosolid compost (BI), leonardite (LE), a metal-contaminated soil, and the soil remediated with either BI or LE in relation to their structural properties, and to explore the role exerted by the HA fractions in controlling soil Cu(II) bioavailability. Potentiometric titrations at pH 5 and ionic strength 0.1M and the Langmuir model were used to obtain the Cu(II) complexing capacity of the HAs examined and the conditional stability constant of the Cu(II)-HA complexes. The Cu(II) complexing capacity increased as the content of acidic ligands, especially COOH groups, aromaticity, and humification degree increased, following the order BI-HAsoil HAssoil HAsoil HAssoil CaCl(2)-extractable Cu content. The results obtained suggested that the pH of the soil-amendment system is the most important chemical property governing Cu(II) solubility and bioavailability in metal-contaminated soils remediated with BI and LE, although soil organic matter and the HA fraction may also be important factors. In particular, binding sites formed by N-, S-, and O-containing acidic functional moieties in HAs may play an important role in the Cu(II) behavior. PMID:20303567

  6. Independent Verification Survey of the Clean Coral Storage Pile at the Johnston Atoll Plutonium Contaminated Soil Remediation Project

    SciTech Connect

    Wilson-Nichols, M.J.; Egidi, P.V.; Roemer, E.K.; Schlosser, R.M.

    2000-09-01

    f I The Oak Ridge National Laboratory (ORNL) Environmental Technology Section conducted an independent verification (IV) survey of the clean storage pile at the Johnston Atoll Plutonium Contaminated Soil Remediation Project (JAPCSRP) from January 18-25, 1999. The goal of the JAPCSRP is to restore a 24-acre area that was contaminated with plutonium oxide particles during nuclear testing in the 1960s. The selected remedy was a soil sorting operation that combined radiological measurements and mining processes to identify and sequester plutonium-contaminated soil. The soil sorter operated from about 1990 to 1998. The remaining clean soil is stored on-site for planned beneficial use on Johnston Island. The clean storage pile currently consists of approximately 120,000 m3 of coral. ORNL conducted the survey according to a Sampling and Analysis Plan, which proposed to provide an IV of the clean pile by collecting a minimum number (99) of samples. The goal was to ascertain wi th 95% confidence whether 97% of the processed soil is less than or equal to the accepted guideline (500-Bq/kg or 13.5-pCi/g) total transuranic (TRU) activity.

  7. Reliability and stability of immobilization remediation of Cd polluted soils using sepiolite under pot and field trials.

    PubMed

    Sun, Yuebing; Xu, Yi; Xu, Yingming; Wang, Lin; Liang, Xuefeng; Li, Ye

    2016-01-01

    Long-term effectiveness and persistence are two important criterias to evaluate alternative remediation technology of heavy metal polluted soils. Pot and field studies showed addition of sepiolite was effective in immobilizing Cd in polluted soils, with significant reduction in TCLP extracts (0.6%-49.6% and 4.0%-32.5% reduction in pot and field experiments, respectively) and plant uptake (14.4%-84.1% and 22.8%-61.4% declines in pot and field studies, correspondingly). However, the applications of sepiolite offered a limited guarantee for the safety of edible vegetables in Cd-polluted soils, depending on the soil type, the Cd pollution type and level, and the dose and application frequency of chemical amendments. Bioassays, such as plant growth, soil enzymatic activities and microbial community diversity, indicated a certain degree of recovery of soil metabolic function. Therefore, sepiolite-assisted in situ remediation is cost-effective, environmentally friendly, and technically applicable, and can be successfully used to reduce Cd enter into the food chain on field scale. PMID:26586633

  8. Technical evaluation report for the demonstration of radio frequency soil decontamination at Site S-1

    SciTech Connect

    Lyon, C.R.; Blanchard, C.F.; Whitt, L.H.

    1995-04-01

    The Air Force`s Armstrong Laboratory at Tyndall Air Force Base, Florida, has supported the research and development of Radio Frequency Soil Decontamination. Radio frequency soil decontamination is essentially a heat-assisted soil vapor extraction process. Site S-1 at Kelly Air Force Base, San Antonio, Texas, was selected for the demonstration of two patented techniques. The site is a former sump that collected spills and surface run-off from a waste petroleum, oils, and lubricants and solvent storage and transfer area. In 1993, a technique developed by the IIT Research Institute using an array of electrodes placed in the soil was demonstrated. In 1994, a technique developed by KAI Technologies, Inc. using a single applicator placed in a vertical borehole was demonstrated. Approximately 120 tons of soil were heated during each demonstration to a temperature of about 150 degrees Celsius.

  9. Obsolete pesticides and application of colonizing plant species for remediation of contaminated soil in Kazakhstan.

    PubMed

    Nurzhanova, Asil; Kalugin, Sergey; Zhambakin, Kabl

    2013-04-01

    In Kazakhstan, there is a problem of finding ways to clean local sites contaminated with pesticides. In particular, such sites are the deserted and destroyed storehouses where these pesticides were stored; existing storehouses do not fulfill sanitary standards. Phytoremediation is one potential method for reducing risk from these pesticides. Genetic heterogeneity of populations of wild and weedy species growing on pesticide-contaminated soil provides a source of plant species tolerant to these conditions. These plant species may be useful for phytoremediation applications. In 2008-2009 and 2011, we surveyed substances stored in 80 former pesticide storehouses in Kazakhstan (Almaty oblast) to demonstrate an inventory process needed to understand the obsolete pesticide problem throughout the country, and observed a total of 354.7 t of obsolete pesticides. At the sites, we have found organochlorine pesticides residues in soil including metabolites of dichlorodiphenyltrichloroethane and isomers of hexachlorocyclohexane. Twenty-four of the storehouse sites showed pesticides concentrations in soil higher than maximum allowable concentration which is equal to 100 μg kg(-1) in Kazakhstan. Seventeen pesticide-tolerant wild plant species were selected from colonizing plants that grew into/near the former storehouse's pesticides. The results have shown that colonizing plant annual and biannual species growing on soils polluted by pesticides possess ability to accumulate organochlorine pesticide residues and reduce pesticide concentrations in soil. Organochlorine pesticides taken up by the plants are distributed unevenly in different plant tissues. The main organ of organochlorine pesticide accumulation is the root system. The accumulation rate of organochlorine pesticides was found to be a specific characteristic of plant species and dependent on the degree of soil contamination. This information can be used for technology development of phytoremediation of pesticide

  10. Nanoparticle-supported lipid bilayers as an in situ remediation strategy for hydrophobic organic contaminants in soils.

    PubMed

    Wang, Hairong; Kim, Bojeong; Wunder, Stephanie L

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are persistent environmental organic contaminants due to their low water solubility and strong sorption onto organic/mineral surfaces. Here, nanoparticle-supported lipid bilayers (NP-SLBs) made of 100-nm SiO2 nanoparticles and the zwitterionic lipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) are investigated as constructs for removing PAHs from contaminated sites, using benzo[a]pyrene (BaP) as an example. DMPC in the form of small unilamellar vesicles (SUVs) or DMPC-NP-SLBs with excess DMPC-SUVs to support colloidal stability, when added to saturated BaP solutions, sorb BaP in ratios of up to 10/1 to 5/1 lipid/BaP, over a 2-week period at 33 °C. This rate increases with temperature. The presence of humic acid (HA), as an analog of soil organic matter, does not affect the BaP uptake rate by DMPC-NP-SLBs and DMPC-SUVs, indicating preferential BaP sorption into the hydrophobic lipids. HA increases the zeta potential of these nanosystems, but does not disrupt their morphology, and enhances their colloidal stability. Studies with the common soil bacteria Pseudomonas aeruginosa demonstrate viability and growth using DMPC-NP-SLBs and DMPC-SUVs, with and without BaP, as their sole carbon source. Thus, NP-SLBs may be an effective method for remediation of PAHs, where the lipids provide both the method of extraction and stability for transport to the contaminant site. PMID:25454259

  11. Systematically biological prioritizing remediation sites based on datasets of biological investigations and heavy metals in soil

    NASA Astrophysics Data System (ADS)

    Lin, Wei-Chih; Lin, Yu-Pin; Anthony, Johnathen

    2015-04-01

    Heavy metal pollution has adverse effects on not only the focal invertebrate species of this study, such as reduction in pupa weight and increased larval mortality, but also on the higher trophic level organisms which feed on them, either directly or indirectly, through the process of biomagnification. Despite this, few studies regarding remediation prioritization take species distribution or biological conservation priorities into consideration. This study develops a novel approach for delineating sites which are both contaminated by any of 5 readily bioaccumulated heavy metal soil contaminants and are of high ecological importance for the highly mobile, low trophic level focal species. The conservation priority of each site was based on the projected distributions of 6 moth species simulated via the presence-only maximum entropy species distribution model followed by the subsequent application of a systematic conservation tool. In order to increase the number of available samples, we also integrated crowd-sourced data with professionally-collected data via a novel optimization procedure based on a simulated annealing algorithm. This integration procedure was important since while crowd-sourced data can drastically increase the number of data samples available to ecologists, still the quality or reliability of crowd-sourced data can be called into question, adding yet another source of uncertainty in projecting species distributions. The optimization method screens crowd-sourced data in terms of the environmental variables which correspond to professionally-collected data. The sample distribution data was derived from two different sources, including the EnjoyMoths project in Taiwan (crowd-sourced data) and the Global Biodiversity Information Facility (GBIF) ?eld data (professional data). The distributions of heavy metal concentrations were generated via 1000 iterations of a geostatistical co-simulation approach. The uncertainties in distributions of the heavy

  12. Removal of heavy metals from kaolin using an upward electrokinetic soil remedial (UESR) technology.

    PubMed

    Wang, Jing-Yuan; Huang, Xiang-Jun; Kao, Jimmy C M; Stabnikova, Olena

    2006-08-25

    An upward electrokinetic soil remedial (UESR) technology was proposed to remove heavy metals from contaminated kaolin. Unlike conventional electrokinetic treatment that uses boreholes or trenches for horizontal migration of heavy metals, the UESR technology, applying vertical non-uniform electric fields, caused upward transportation of heavy metals to the top surface of the treated soil. The effects of current density, treatment duration, cell diameter, and different cathode chamber influent (distilled water or 0.01 M nitric acid) were studied. The removal efficiencies of heavy metals positively correlated to current density and treatment duration. Higher heavy metals removal efficiency was observed for the reactor cell with smaller diameter. A substantial amount of heavy metals was accumulated in the nearest to cathode 2 cm layer of kaolin when distilled water was continuously supplied to the cathode chamber. Heavy metals accumulated in this layer of kaolin can be easily excavated and disposed off. The main part of the removed heavy metals was dissolved in cathode chamber influent and moved away with cathode chamber effluent when 0.01 M nitric acid was used, instead of distilled water. Energy saving treatment by UESR technology with highest metal removal efficiencies was provided by two regimes: (1) by application of 0.01 M nitric acid as cathode chamber influent, cell diameter of 100 mm, duration of 18 days, and constant voltage of 3.5 V (19.7 k Wh/m(3) of kaolin) and (2) by application of 0.01 M nitric acid as cathode chamber influent, cell diameter of 100 cm, duration of 6 days, and constant current density of 0.191 mA/cm(2) (19.1 k Wh/m(3) of kaolin). PMID:16504386

  13. CHARACTERIZATION OF CONDITIONS OF NATURAL GAS STORAGE RESERVOIRS AND DESIGN AND DEMONSTRATION OF REMEDIAL TECHNIQUES FOR DAMAGE MECHANISMS FOUND THEREIN

    SciTech Connect

    J.H. Frantz Jr; K.G. Brown; W.K. Sawyer; P.A. Zyglowicz; P.M. Halleck; J.P. Spivey

    2004-12-01

    The underground gas storage (UGS) industry uses over 400 reservoirs and 17,000 wells to store and withdrawal gas. As such, it is a significant contributor to gas supply in the United States. It has been demonstrated that many UGS wells show a loss of deliverability each year due to numerous damage mechanisms. Previous studies estimate that up to one hundred million dollars are spent each year to recover or replace a deliverability loss of approximately 3.2 Bscf/D per year in the storage industry. Clearly, there is a great potential for developing technology to prevent, mitigate, or eliminate the damage causing deliverability losses in UGS wells. Prior studies have also identified the presence of several potential damage mechanisms in storage wells, developed damage diagnostic procedures, and discussed, in general terms, the possible reactions that need to occur to create the damage. However, few studies address how to prevent or mitigate specific damage types, and/or how to eliminate the damage from occurring in the future. This study seeks to increase our understanding of two specific damage mechanisms, inorganic precipitates (specifically siderite), and non-darcy damage, and thus serves to expand prior efforts as well as complement ongoing gas storage projects. Specifically, this study has resulted in: (1) An effective lab protocol designed to assess the extent of damage due to inorganic precipitates; (2) An increased understanding of how inorganic precipitates (specifically siderite) develop; (3) Identification of potential sources of chemical components necessary for siderite formation; (4) A remediation technique that has successfully restored deliverability to storage wells damaged by the inorganic precipitate siderite (one well had nearly a tenfold increase in deliverability); (5) Identification of the types of treatments that have historically been successful at reducing the amount of non-darcy pressure drop in a well, and (6) Development of a tool that can

  14. SAFETY IMPROVES DRAMATICALLY IN FLUOR HANFORD SOIL AND GROUNDWATER REMEDIATION PROJECT

    SciTech Connect

    GERBER MS

    2007-12-05

    This paper describes dramatic improvements in the safety record of the Soil and Groundwater Remediation Project (SGRP) at the Hanford Site in southeast Washington state over the past four years. During a period of enormous growth in project work and scope, contractor Fluor Hanford reduced injuries, accidents, and other safety-related incidents and enhanced a safety culture that earned the SGRP Star Status in the Department of Energy's (DOE's) Voluntary Protection Program (VPP) in 2007. This paper outlines the complex and multi-faceted work of Fluor Hanford's SGRP and details the steps taken by the project's Field Operations and Safety organizations to improve safety. Holding field safety meetings and walkdowns, broadening safety inspections, organizing employee safety councils, intensively flowing down safety requirements to subcontractors, and adopting other methods to achieve remarkable improvement in safety are discussed. The roles of management, labor and subcontractors are detailed. Finally, SGRP's safety improvements are discussed within the context of overall safety enhancements made by Fluor Hanford in the company's 11 years of managing nuclear waste cleanup at the Hanford Site.

  15. Safety Improves Dramatically In Fluor Hanford Soil and Groundwater Remediation Project

    SciTech Connect

    Foster, A.L.; Gerber, M.S.; VonBargen, B.H.

    2008-07-01

    This paper describes dramatic improvements in the safety record of the Soil and Groundwater Remediation Project (SGRP) at the Hanford Site in southeast Washington state over the past four years. During a period of enormous growth in project work and scope, contractor Fluor Hanford reduced injuries, accidents, and other safety-related incidents and enhanced a safety culture that earned the SGRP Star Status in the Department of Energy's (DOE's) Voluntary Protection Program (VPP) in 2007. This paper outlines the complex and multi-faceted work of Fluor Hanford's SGRP and details the steps taken by the project's Field Operations and Safety organizations to improve safety. Holding field safety meetings and walk-downs, broadening safety inspections, organizing employee safety councils, intensively flowing down safety requirements to subcontractors, and adopting other methods to achieve remarkable improvement in safety are discussed. The roles of management, labor and subcontractors are detailed. Finally, SGRP's safety improvements are discussed within the context of overall safety enhancements made by Fluor Hanford in the company's 11 years of managing nuclear waste cleanup at the Hanford Site. (authors)

  16. The use of vetiver for remediation of heavy metal soil contamination.

    PubMed

    Antiochia, Riccarda; Campanella, Luigi; Ghezzi, Paola; Movassaghi, K

    2007-06-01

    The use of Vetiveria zizanioides (vetiver) was studied to evaluate its efficiency for the remediation of soils contaminated by heavy metals. Vetiver plants were tested for Cr, Cu, Pb and Zn. Phytoextraction and bioremediation experiments were carried out by irrigating the vetiver plants and the dry plants with solutions containing suitable amounts of Cr, Cu, Pd and Zn. The concentrations of the heavy metals were determined in both experiments in shoot and root parts of vetiver plants using inductively coupled plasma atomic emission spectroscopy after a mineralization step. Phytoextraction experiments showed a poor efficiency of vetiver for Cr and Cu uptake (both less than 0.1% in shoots and roots after 30 days), but a quite high capability of Pb and Zn uptake (0.4% in shoots and 1% in roots for Pb and 1% both in shoots and in roots for Zn, after 30 days). For these reasons the vetiver plant can be considered a quite good "hyperaccumulator" only for Pb and Zn. As for bioremediation experiments, the vetiver plant showed heavy metal uptake values significantly lower than those obtained with other biological substrates. PMID:17468861

  17. Ex-situ field application of electrokinetics for remediation of shooting-range soil.

    PubMed

    Lee, Keun-Young; Kim, Hyun-A; Lee, Woo-Chun; Kim, Soon-Oh; Lee, Jong-Un; Kwon, Young-Ho; Kim, Kyoung-Woong

    2012-01-01

    Electrokinetic process for remediation of a shooting-range site was evaluated in this study. By field operation for 100 days, the newly designed electrokinetic system was evaluated for process stability, performance, and efficiency. The field site of this study was an abandoned military shooting range located in the Civilian Control Line of South Korea. The target area, only, was heavily contaminated by Pb and Cu to a depth of 0.5 m. After dry-sieving of the field soil to separate particulate Pb, two cells in a hexagonal (two-dimensional) arrangement, including ten anodes outside the cell and two cathodes in the middle, were prepared. The pH of each electrolyte was adjusted by use of concentrated HNO(3), resulting in acid-enhanced electrokinetics. The monitoring results indicated that overall removal of heavy metals (Pb, Cu) was achieved, and that both heavy metals were removed from outside the cell. The average final efficiency of removal of Pb and Cu was 39.5 ± 35 and 63.8 ± 12%, respectively. Although the feasibility of this system was confirmed, for commercialization of the process confirmed drawbacks must be improved by further study. PMID:21858453

  18. Former DDT factory in Pakistan revisited for remediation: severe DDT concentrations in soils and plants from within the area.

    PubMed

    Younas, Asma; Hilber, Isabel; ur Rehman, Shafique; Khwaja, Mahmood; Bucheli, Thomas D

    2013-04-01

    A factory in Amman Garh near Nowshera, Khyber Pakhtunkhwa, Pakistan, produced dichlorodiphenyltrichloroethane (DDT) from 1963-1994. Consequently, earlier papers reported a soil contamination in the per mille range inside the former factory wall (88 m × 106 m) and up to 10 mg/kg of DDT in the surroundings in 2005-2007. The site within the factory wall was remonitored system