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

Description: 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.
Date: July 31, 2007
Creator: Davison, L.
Partner: UNT Libraries Government Documents Department

New Pump and Treat Facility Remedial Action Work Plan For Test Area North Final Groundwater Remediation, Operable Unit 1-07B

Description: This remedial action work plan identifies the approach and requirements for implementing the medial zone remedial action for Test Area North, Operable Unit 1-07B, at the Idaho National Laboratory. This plan details the management approach for the construction and operation of the New Pump and Treat Facility (NPTF). As identified in the remediatial design/remedial action scope of work, a separate remedial design/remedial action work plan will be prepared for each remedial component of the Operable Unit 1-07B remedial action.
Date: June 12, 2007
Creator: Nelson, L. O.
Partner: UNT Libraries Government Documents Department

Deployment Support Leading to Implementation

Description: The following paragraphs summarize the progress of each research project funded under the WVU Cooperative Agreement during the third quarter of 1997 (July - September 1997). The projects are arranged according to their 1997 WVU task number. WVU Focus Area 1.0: Subsurface Contaminants, Containment and Remediation Task No. 1.1: Project discontinued. Task No. 1.2: Development of Standard Test Protocols and Barrier Design Models for Desiccation Barriers (K. Amininan & S. Ameri): A number of experiments were preformed this period to evaluate the ability of the dried sand-packs to act as a barrier to liquids. Water infiltration tests were done with a constant head, dispersing 80 ml of water, and by adding water in small increments. Results indicate that when the water is spilled over the sand-pack, it has the tendency to channel through the sand-pack, significantly reducing the capacity of the dried zone to retain liquid contaminants. This appears to be largely influenced by particle size. As the particle size is reduced, the capillary forces spread the water and prevent/delay channels from forming. The measured permeability values were in agreement with those measured with air. The water retention capacity and capillary rise were largely influenced by time and showed no sensitivity to channeling. The water retention capacity tests suggest the sand-packs can retain more water than the expected. Two sets of water infiltration and drying experiments were designed to evaluate the CAB�s ability to prevent spills from spreading. Ten ml of water was injected every 20 minutes and 80 ml of water was added at one time. When injected slowly, results showed the drying process to be similar to the original drying process. The second set indicted the drying process follows a slowly declining drying with no break through. Results also suggested that air flow through the sand-pack can remove ...
Date: October 1, 1997
Creator: Cook, E. E.
Partner: UNT Libraries Government Documents Department

Operable Unit 3-13, Group 7, SFE-20 Hot Waste Tank System Remedial Action Request

Description: This Remedial Action Report summarizes activities undertaken to remediate the Operable Unit 3-13, Group 7, SFE-20 Hot Waste Tank System at the Idaho Nuclear Technology and Engineering Center at the Idaho National Laboratory Site. The site addressed in this report was 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 the site have been accomplished and is hereafter considered a No Further Action site.
Date: June 30, 2009
Creator: Davison, L.
Partner: UNT Libraries Government Documents Department

Immobilization of toxic metals and radionuclides in porous and fractured media: Optimizing biogeochemical reduction versus geochemical oxidation. 1997 annual progress report

Description: 'The purpose of the authors research is to provide an improved understanding and predictive capability of the mechanisms that allow metal-reducing bacteria to be effective in the bioremediation of subsurface environments contaminated with toxic metals and radionuclides. The research findings of the work plan will (1) provide new insights into the previously unexplored areas of competing geochemical and microbiological oxidation/reduction reactions that govern the fate and transport of redox sensitive contaminants in subsurface environments and (2) provide basic knowledge to define the optimum conditions for the microbial reduction and concomitant immobilization of toxic metals and radionuclides in the subsurface. Strategies that use in situ contaminant immobilization can be efficient and cost-effective remediation options. This project will focus on the following specific objectives. Develop an improved understanding of the rates and mechanisms of competing geochemical and microbiological oxidation/reduction reactions that govern the fate and transport of uranium (U), chromium (Cr), and cobalt-EDTA (Co-EDTA) in the subsurface. Quantify the conditions that optimize the microbial reduction of toxic metals and radionuclides for the purpose of contaminant containment and remediation in heterogeneous systems that have competing geochemical oxidation, sorption, and organic ligands.'
Date: September 1, 1997
Creator: Jardine, P.M.; Brooks, S.C.; Saiers, J.E.; Phelps, T.J.; Zachara, J. & Fendorf, S.E.
Partner: UNT Libraries Government Documents Department

Complete detoxification of short chain chlorinated aliphatic compounds: Isolation of halorespiring organisms and biochemical studies of the dehalogenating enzyme systems. 1998 annual progress report

Description: 'Widespread use and careless handling, storage and disposal practices, have lead to the dissemination of chlorinated short chain aliphatics into groundwater systems. These compounds are toxic and the presence of chlorinated ethenes and chlorinated propanes in the environment is of public concern. Halorespiration is a newly recognized anaerobic process by which certain bacteria use chlorinated compounds as terminal electron acceptors in their energy metabolism. In contrast to co-metabolic dechlorination, which is fortuitous, slow, and without benefit to the organisms, halorespiration, characterized by high dechlorination rates, is a specific metabolic process beneficial to the organism. The goals are to isolate and characterize organisms which use chlorinated ethenes (including tetrachloroethene [PCE], trichloroethene [TCE], cis-dichloroethene [cis-DCE], and vinyl chloride [VC], or 1,2-dichloropropane [1,2-D]) as electron acceptors in their energy metabolism. Better understanding of the physiology and phylogeny of the halorespiring organisms as well as the biochemistry of the dehalogenating enzyme systems, will greatly enhance the authors knowledge of how these organisms can successfully be employed in the bioremediation of contaminated sites. This report summarizes the results of 1.5 years of a 2-year project. Anaerobic microcosms were established using a variety of geographically distinct sediments. In several microcosms complete dechlorination of PCE to ethene (ETH), and 1,2-D to propene was observed. Upon subsequent transfers to anaerobic medium, four sediment-free, methanogenic enrichment cultures were obtained that dechlorinated PCE to ETH, and two cultures that dechlorinated 1,2-D to propene. 2-Bromoethanesulfonate (BES), a well known inhibitor of methanogens, did not inhibit the dechlorination of 1,2-D to propene or the dechlorination of PCE to cis-DCE. However, the complete dechlorination of PCE to VC and ETH was severely inhibited. They could also show that BES inhibited the dechlorination of chloroethenes in cultures without methanogens. Therefore, BES should not be used to attribute dechlorination activities to methanogens.'
Date: June 1, 1998
Creator: Tiedje, J.M.
Partner: UNT Libraries Government Documents Department

Complete detoxification of short chain chlorinated aliphatics: Isolation of halorespiring organisms and biochemical studies of the dehalogenating enzyme systems. 1997 annual progress report

Description: 'The objectives of the research within this grant are: (1) Isolation and characterization of chlororespiring organisms responsible for the complete dehalogenation of chlorinated ethenes and propanes. (2) Development of conditions that yield high cell densities and induce dechlorinating activity. (3) Development of assay systems to detect the dechlorinating activity in cell-free extracts. (4) Purification and characterization of the dehalogenating enzymes. Anaerobic microcosms were obtained from a variety of geographically different sediment samples. In several microcosms complete dechlorination of tetrachloroethene (PCE) to ethene (ETH), and 1,2-dichloropropane ( 1,2-D) and/or 1,2,3-trichloropropane to propene was observed. Upon subsequent transfers to anaerobic medium, sediment-free, methanogenic enrichment cultures were obtained that dechlorinated PCE to ETH, and 1,2-D to propene, respectively. 2-Bromoethanesulfonate (BES), a well known inhibitor of methanogens, did not inhibit the dechlorination of 1,2-D to propene and the dechlorination of PCE to cis-dichloroethene (cis-DCE). However,-the complete dechlorination of PCE to vinyl chloride (VC) and ETH was severely inhibited. The authors could show that BES inhibited the dechlorination of chloroethenes in cultures not containing methanogens. Previous to this study, BES was believed to be aspecific inhibitor of methanogens and the inhibitory effect of BES on declorination was explained by the involvement of methanogens in the dechlorination process. The non-methanogenic cultures obtained after the BES treatment were subsequently transferred to medium riot containing BES and complete dechlorination of PCE to ETH was observed as was in the original microcosms. Subcultures were further enriched with PCE, cis-DCE, VC, or 1,2-D as the only available electron acceptor and acetate, or acetate plus hydrogen as the only available electron donor(s). To date these cultures have undergone up to 45 transfers. Interestingly, two cultures that originally dechlorinated PCE to ETH, but were then enriched with cis-DCE or VC, lost their ability to-dechlorinate PCE or TCE. This finding indicates that different ...
Date: January 1, 1997
Creator: Loeffler, F.E. & Tiedje, J.M.
Partner: UNT Libraries Government Documents Department

Construction of bending magnet beamline at the APS for environmental studies. 1998 annual progress report

Description: 'Design and construction of a bending magnet beamline at the Advanced Photon Source (APS) by the Pacific Northwest Consortium-Collaborative Access Team (PNC-CAT). The beamline will be optimized for x-ray absorption spectroscopy (XAS) studies with a major focus on environmental issues. The beamline will share the experimental facilities under development at the neighboring undulator based insertion device beamline. It will utilize these facilities for XAS of both bulk and surface samples, with spatial and elemental imaging, on toxic and radioactive samples. It will help meet the rapidly growing need for the application of these techniques to environmental problems. This report summarizes progress after 1-1/2 years of a 3-year project. The original scope of the project was to build a basic bending magnet beamline. Since the start of the project the authors have obtained addition funding from DOE-BES for the PNC-CAT activities. This has allowed us to expand the scope of the original proposed bending magnet beamline. Additional items now planned include a full sized experimental enclosure separate from the first optical enclosure (FOE), a white beam vertically collimating/focusing mirror providing improved flux and focusing, and enhanced experimental capabilities. Construction of the FOE and new experimental enclosure are complete along with full sector utilities, and the FOE is currently undergoing validation for its radiation integrity. The major beamline components are still being funded by the original EMSP project, and their status is described'
Date: June 1, 1998
Creator: Stern, E.A.
Partner: UNT Libraries Government Documents Department

Containment of toxic metals and radionuclides in porous and fractured media: Optimizing biogeochemical reduction versus geochemical oxidation. 1998 annual progress report

Description: 'The purpose of this research is to provide an improved understanding and predictive capability of the mechanisms that allow metal-reducing bacteria to be effective in the bioremediation of subsurface environments contaminated with toxic metals and radionuclides. The study is motivated by the likelihood that subsurface microbial activity can effectively alter the redox state of toxic metals and radionuclides so that they are immobilized for long time periods. The objectives are to: (1) develop an improved understanding of the rates and mechanisms of competing geochemical oxidation and microbiological reduction reactions that govern the fate and transport of redox-sensitive metals and radionuclides in the subsurface, and (2) quantify the conditions that optimize the microbial reduction of toxic metals and radionuclides, for the purpose of contaminant containment and remediation in heterogeneous systems that have competing geochemical oxidation, sorption, and organic ligands. The overall goal of this project is to use basic research to develop a cost effective remediation strategy that employs in-situ contaminant immobilzation. Specifically, the authors will develop active biowall technologies to contain priority EM contaminant plumes in groundwater. This report summarizes work after 1.5 y of a 3 y project.'
Date: June 1, 1998
Creator: Jardine, P.M. & Brooks, S.C.
Partner: UNT Libraries Government Documents Department

Behavior of dense, immiscible solvents in fractured clay-rich soils. 1998 annual progress report

Description: 'This research project addresses the nature and and distribution of DNAPL sources (typically chlorinated solvents) in fractured clays or shales and the potential for natural attenuation of plumes derived from these sources. Specific goals include: (1) determining whether typical DNAPLs can penetrate fractures and the fine-grained matrix pore structure for head values within the range expected for a typical DNAPL spill; (2) investigate methods of measuring or estimating fracture or matrix entry pressure and pressure-saturation curves for these materials; (3) experimentally determine whether DNAPL residuals in fractures can be significantly depleted by dissolution and diffusion into the fine-grained matrix over the time-frame relevant to many contaminant investigation and remediation programs; and (4) assess potential for natural attenuation of common DNAPLs (TCE and its degradation products) in these deposits. Preliminary investigations indicate that DNAPL source removal will be a much more difficult and slower process for fractured clay-rich deposits than for granular deposits. These basic research investigations are needed to build the scientific framework for assessment of remediation options or for determining whether remediation, at least for the source zone, should be considered Technically Impractible (TI). This report summarizes progress made during the first 1.7 years of a 3-year project. The project investigates the behavior of DNAPLs in two fractured clay-rich materials: weathered shales at Oak Ridge National Lab. in east Tennessee; and weathered glacial till in southern Ontario. The materials, although very different in origin, are similar in terms of fracturing, porosity and hydraulic conductivity and DNAPLs are expected to behave in similar fashions in the two materials. This allows the researchers to share their expertise, as well as helping to determine whether the findings of these studies are applicable to a broader spectrum of fractured clay-rich materials. Results to date for the major sub-projects are briefly described.'
Date: June 1, 1998
Creator: Mckay, L.D.; Sanseverino, J.; Jardine, P.M.; Brooks, S.C.; Cherry, J.A. & Parker, B.L.
Partner: UNT Libraries Government Documents Department

Behavior of dense immiscible solvents in fractured clay-rich soils. Technical progress report, 1997

Description: 'The overall goal of the research program is to develop a better understanding of the physical and chemical factors and processes influencing fate and transport of immiscible and dissolved-phase dense solvents in groundwater in fractured, highly weathered clays and shales. These widespread materials are much different, physically and chemically, from granular soils or fractured low porosity rocks, which are the media used for most previous investigations of solvent behavior. The investigations are needed to provide a basic scientific framework for assessment of solvent transport and remediation in fractured clay-rich deposits. Specific experimental objectives include: (1) Determine the nature and distribution of porosity in these materials, and its influence on pressure-saturation behavior for immiscible solvents. This includes determining values for entry pressure, residual saturation, fracture aperture and matrix pore size distribution, as well as assessment of methodologies for measuring/characterizing these parameters. (2) Determine the influence of dissolution, sorption and diffusion into the matrix on long term disappearance of residual solvents in the fractured materials. (3) Assessment of the potential for natural attenuation of common solvents, especially TCE, in these deposits. This includes investigating the natural geochemistry and microbiology of the deposits, and assessing biologically-mediated degradation of solvents in the laboratory and at existing contaminated field sites.'
Date: October 13, 1997
Creator: McKay, L.D.
Partner: UNT Libraries Government Documents Department

Advanced experimental analysis of controls on microbial Fe(III) oxide reduction. 1998 annual progress report

Description: 'Understanding factors which control the long-term survival and activity of Fe(III)-reducing bacteria (FeRB) in subsurface sedimentary environments is important for predicting their ability to serve as agents for bioremediation of organic and inorganic contaminants. This project seeks to refine the authors quantitative understanding of microbiological and geochemical controls on bacterial Fe(III) oxide reduction and growth of FeRB, using laboratory reactor systems which mimic to varying degrees the physical and chemical conditions of subsurface sedimentary environments. Methods for studying microbial Fe(III) oxide reduction and FeRB growth in experimental systems which incorporate advective aqueous phase flux are being developed for this purpose. These methodologies, together with an accumulating database on the kinetics of Fe(III) reduction and bacterial growth with various synthetic and natural Fe(III) oxide minerals, will be applicable to experimental and modeling studies of subsurface contaminant transformations directly coupled to or influenced by bacterial Fe(III) oxide reduction and FeRB activity. This report summarizes research accomplished after approximately 1.5 yr of a 3-yr project. A central hypothesis of the research is that advective elimination of the primary end-product of Fe(III) oxide reduction, Fe(II), will enhance the rate and extent of microbial Fe(III) oxide reduction in open experimental systems. This hypothesis is based on previous studies in the laboratory which demonstrated that association of evolved Fe(II) with oxide and FeRB cell surfaces (via adsorption or surface precipitation) is a primary cause for cessation of Fe(III) oxide reduction activity in batch culture experiments. Semicontinuous culturing was adopted as a first approach to test this basic hypothesis. Synthetic goethite or natural Fe(III) oxide-rich subsoils were used as Fe(III) sources, with the Fe(III)-reducing bacterium Shewanella alga as the test organism.'
Date: June 1, 1998
Creator: Roden, E.E. & Urrutia, M.M.
Partner: UNT Libraries Government Documents Department

Advanced experimental analysis of controls on microbial Fe(III) oxide reduction. First year progress report

Description: 'The authors have made considerable progress toward a number of project objectives during the first several months of activity on the project. An exhaustive analysis was made of the growth rate and biomass yield (both derived from measurements of cell protein production) of two representative strains of Fe(III)-reducing bacteria (Shewanellaalga strain BrY and Geobactermetallireducens) growing with different forms of Fe(III) as an electron acceptor. These two fundamentally different types of Fe(III)-reducing bacteria (FeRB) showed comparable rates of Fe(III) reduction, cell growth, and biomass yield during reduction of soluble Fe(III)-citrate and solid-phase amorphous hydrous ferric oxide (HFO). Intrinsic growth rates of the two FeRB were strongly influenced by whether a soluble or a solid-phase source of Fe(III) was provided: growth rates on soluble Fe(III) were 10--20 times higher than those on solid-phase Fe(III) oxide. Intrinsic FeRB growth rates were comparable during reduction of HF0 and a synthetic crystalline Fe(III) oxide (goethite). A distinct lag phase for protein production was observed during the first several days of incubation in solid-phase Fe(III) oxide medium, even though Fe(III) reduction proceeded without any lag. No such lag between protein production and Fe(III) reduction was observed during growth with soluble Fe(III). This result suggested that protein synthesis coupled to solid-phase Fe(III) oxide reduction in batch culture requires an initial investment of energy (generated by Fe(III) reduction), which is probably needed for synthesis of materials (e.g. extracellular polysaccharides) required for attachment of the cells to oxide surfaces. This phenomenon may have important implications for modeling the growth of FeRB in subsurface sedimentary environments, where attachment and continued adhesion to solid-phase materials will be required for maintenance of Fe(III) reduction activity. Despite considerable differences in the rate and pattern of FeRB growth with different Fe(III) forms, a roughly consistent long-term biomass yield of 5 to 15 mg protein ...
Date: July 1, 1997
Creator: Roden, E.E. & Urrutia, M.M.
Partner: UNT Libraries Government Documents Department

Advanced high resolution seismic imaging, material properties estimation and full wavefield inversion for the shallow subsurface. 1998 annual progress report

Description: 'The authors are developing advanced seismic data processing, imaging, and inversion methods for high resolution seismic reflection/refraction imaging and material property estimation of the shallow subsurface. The imaging methods are being developed to map the structural and material properties of aquifers and aquitards. This report summarizes work completed in the first seven months of a three year project which began in November 1997. The research is proceeding along three lines: data acquisition, data processing, and algorithm development.'
Date: June 1, 1998
Creator: Levander, A.; Zelt, C.A. & Symes, W.W.
Partner: UNT Libraries Government Documents Department

Design and construction of deinococcus radiodurans for biodegradation of organic toxins at radioactive DOE waste sites. 1998 annual progress report

Description: 'A 1992 survey of DOE waste sites indicates that about 32% of soils and 45% of groundwaters at these sites contain radionuclides and metals plus an organic toxin class. The most commonly reported combinations of these hazardous compounds being radionuclides and metals (e.g., U, Pu, Cs, Pb, Cr, As) plus chlorinated hydrocarbons (e.g., trichloroethylene), fuel hydrocarbons (e.g., toluene), or polychlorinated biphenyls (e.g., Arochlor 1248). These wastes are some of the most hazardous pollutants and pose an increasing risk to human health as they leach into the environment. The objective of this research is to develop novel organisms, that are highly resistant to radiation and the toxic effects of metals and radionuclides, for in-situ bioremediation of organic toxins. Few organisms exist that are able to remediate such environmental organic pollutants, and among those that can, the bacteria belonging to the genus Pseudomonas are the most characterized. Unfortunately, these bacteria are very radiation sensitive. For example, Pseudomonas spp. is even more sensitive than Escherichia coli and, thus, is not suitable as a bioremediation host in environments subjected to radiation. By contrast, D. radiodurans, a natural soil bacterium, is the most radiation resistant organism yet discovered; it is several thousand times more resistant to ionizing radiation than Pseudomonas. The sophisticated gene transfer and expression systems the authors have developed for D. radiodurans over the last eight years make this organism an ideal candidate for high-level expression of genes that degrade organic toxins, in radioactive environments. The authors ultimate aim is to develop organisms and approaches that will be useful for remediating the large variety of toxic organic compounds found in DOE waste sites that are too radioactive to support other bioremediation organisms. This report summarizes work after the first 6 months of a 3-year project.'
Date: June 1, 1998
Creator: Daly, M.J.; Wackett, L.P. & Minton, K.W.
Partner: UNT Libraries Government Documents Department

Microbial mineral transformations at the Fe(II)/Fe(III) redox boundary for solid phase capture of strontium and other metal/radionuclide contaminants. 1998 annual progress report

Description: 'The Research objectives of this report are to determine microbiological and geochemical controls on carbonate mineral preciptation reactions, and identify contributions of these processes to the solid phase capture of strontium and other metal/radionuclide contaminants. The study is relevant to the development of new clean-up strategies for DOE sites where strontium and other metal/radionuclides exist as ubiquitous and often mobile contaminants. The work summarized in this report encompasses two years of a three-year project investigating the use of bacteria to concentrate and immobilize strontium, as well as other metal/radionuclide, contaminants. Major accomplishments to date include completion of metal sorption studies with bacteria and hydrous ferric oxides (HFO), assessment of the impact of strontium on bacterial Fe(III)-reduction, induction of carbonate mineral precipitation and solid phase capture of strontium under Fe(III)-reducing conditions, and discovery of a procedure to attain rapid high-level concentration of strontium in microbiologically produced calcite.'
Date: June 1, 1998
Creator: Ferris, F.G.
Partner: UNT Libraries Government Documents Department

Microbial mineral transformations at the Fe(II)/Fe(III) redox boundary for solid phase capture of strontium and other metal/radionuclide contaminants. Annual progress report, September 15, 1996--June 15, 1997

Description: 'The objectives of the project remain the same as those stated in the original proposal. Specifically, to determine microbiological and geochemical controls on carbonate mineral precipitation reactions that are caused by bacterial reduction of Fe(III)-oxides, and identify contributions of these processes to solid phase capture of strontium and other metal/radionuclide contaminants. The project on microbial mineral transformations at the Fe(II)/Fe(III) redox boundary for the solid phase capture of strontium is progressing well. Thus far, the authors have been able to demonstrate that: pH and DIC concentrations increase during microbial reduction of HFO in batch culture experiments with G. metallireducens lasting 30 days with high concentrations of strontium (1.0 \265m) and calcium (10 \265m) do not inhibit microbial HFO reduction, the extent of change in pH and DIC concentrations brings about supersaturation with respect to carbonate minerals including siderite (FeCO{sub 3}), strontianite (SrCO{sub 3}), and calcite/aragonite (CaCO{sub 3}); in addition, precipitation of siderite has been documented in cultures of HFO reducing bacteria significant amounts of strontium and calcium (40 to 50% of the total initial concentration) sorb to particulate solids (i.e., HFO and bacteria cells)-in batch culture experiments l sorption of strontium to HFO conforms with Langmuir single site sorption models derived from corresponding mass action and mass balance relationships anticipated from thermodynamic equilibrium considerations the sorption behavior of strontium with S. alga is more complex and seems to involve two sets of reactive surface sites on the bacterial cells; a high affinity site of low total sorption capacity, and a low affinity site with high sorption capacity the total strontium sorption capacities of S. alga and HFO are comparable the observed solid phase partioning of strontium in the culture experiments is in excellent agreement with sorption characteristics measured with HFO and S. alga.'
Date: January 1, 1997
Creator: Ferris, F.G. & Roden, E.E.
Partner: UNT Libraries Government Documents Department

The migration and entrapment of DNAPLs in physically and chemically heterogeneous porous media. 1998 annual progress report

Description: 'The migration and entrapment of dense nonaqueous phase liquids (DNAPLs) at hazardous waste sites is typically believed to be controlled by physical heterogeneities. This belief is based upon the assumption that permeability and capillary properties are determined by soil texture. These transport properties however, also depend on porous media wettability characteristics, which may vary spatially in a formation due to variations in aqueous phase chemistry, contaminant aging, and/or variations in mineralogy and organic matter distributions. The overall objective of this research is to investigate the influence of such coupled physical and chemical heterogeneities on the migration and entrapment of DNAPLs in the saturated zone. This research includes laboratory and numerical investigations for a matrix of organic contaminants and solid media encompassing a range of wettability characteristics. Specific objectives include: (1) quantification of system wettability and interfacial tensions; (2) determination of transport property relations; (3) two-dimensional infiltration experiments; (4) modification of a continuum based multiphase flow simulator to account for physical heterogeneity, saturation independent and saturation dependent wettability, and concentration dependent wettability and interfacial tension; and (5) utilization of this model to explore the potential influence of coupled physical and chemical heterogeneities on the migration of DNAPLs and the development of innovative remediation schemes. The accomplishment of the above research objectives will facilitate the characterization and remediation of contaminated field sites. This section summarizes research conducted towards the accomplishment of goals (1), (2), (4), and (5) during the first 1.5 years of this 3-year project. Goal (3) builds upon results from the other objectives and will be initiated in the coming year.'
Date: June 1, 1998
Creator: Abriola, L.M. & Demond, A.H.
Partner: UNT Libraries Government Documents Department

The migration and entrapment of DNAPLs in physically and chemically heterogeneous porous media. Annual progress report, September 15, 1996--August 25, 1997

Description: 'The overall objective of this research is to investigate the influence of coupled physical and chemical heterogeneity on the migration and entrapment of DNAPLs in the saturated zone. This research includes laboratory and numerical investigations for a matrix of fluid and solid properties encompassing a range of wettability characteristics. Specific objectives include: (1) quantification of medium wettability and interfacial tensions; (2) determination of hydraulic property relations; (3) two-dimensional infiltration experiments; (4) modification of a continuum based multiphase flow simulator to account for physical heterogeneity, saturation independent and saturation dependent wettability, and concentration dependent wettability and interfacial tension; and (5) utilization of this model to explore the potential influence of coupled physical and chemical heterogeneities on the migration of DNAPLs and the development of innovative remediation schemes. Research conducted during this period was directed primarily towards the accomplishment of goals (1), (2), (4) and (5); specific details are given below. Goal (3) builds upon results from the other objectives and will, therefore, be started in the coming year.'
Date: January 1, 1997
Creator: Abriola, L.M. & Demond, A.H.
Partner: UNT Libraries Government Documents Department

Dynamics of coupled contaminant and microbial transport in heterogeneous porous media. 1997 annual progress report

Description: 'Dynamic microbial attachment/detachment occurs in subsurface systems in response to changing environmental conditions caused by contaminant movement and degradation. Understanding the environmental conditions and mechanisms by which anaerobic bacteria partition between aqueous and solid phases is a critical requirement for designing and evaluating in situ bioremediation efforts. This interdisciplinary research project will provide fundamental information on the attachment/detachment dynamics of anaerobic bacteria in heterogeneous porous media under growth and growth-limiting conditions. Experiments will provide information on passive and active attachment/detachment mechanisms used by growing anaerobes capable of reductive dechlorination. Theoretical representations of these attachment/detachment mechanisms will be incorporated into existing groundwater flow and contaminant transport models that incorporate heterogeneity effects and can be used to predict behavior at field scales. These mechanistic-based models will be tested against experimental data provided through controlled laboratory experiments in heterogeneous porous media in large (meter-scale) 2-D flow cells. In addition to a mechanistic-based predictive model, this research will lead to new theories for the transient spatial distribution of microbial populations and contaminant plumes in heterogeneous porous media, improving the capability for designing staged remediation strategies for dealing with mixed contaminants.'
Date: June 1, 1997
Creator: Ginn, T.R.; Boone, D.R.; Fletcher, M.M.; Friedrich, D.M. & Murphy, E.M.
Partner: UNT Libraries Government Documents Department

Dynamics of coupled contaminant and microbial transport in heterogeneous porous media. 1998 annual progress report

Description: 'Dynamic microbial attachment/detachment occurs in subsurface systems in response to changing environmental conditions caused by contaminant movement and degradation. Understanding the environmental conditions and mechanisms by which anaerobic bacteria partition between aqueous and solid phases is a critical requirement for designing and evaluating in-situ bioremediation efforts. This interdisciplinary research project will provide fundamental information on the attachment/detachment dynamics of anaerobic bacteria in heterogeneous porous media under growth and growth-limiting conditions. Experiments will provide information on passive and active attachment/detachment mechanisms used by growing anaerobes capable of reductive dechlorination. Theoretical representations of these attachment/detachment mechanisms will be incorporated into existing flow and transport models that incorporate heterogeneity effects and can be used to predict behavior at field scales. These mechanistic-based models will be tested against experimental data provided through controlled laboratory experiments in heterogeneous porous media in large (meter-scale) 2-D flow cells. In addition to a mechanistic-based predictive model, this research will lead to new theories for the transient spatial distribution of microbial populations and contaminant plumes in heterogeneous porous media, improving the capability for designing staged remediation strategies for dealing with mixed contaminants.'
Date: June 1, 1998
Creator: Ginn, T.R.; Cushman, J.H.; Murphy, E.M. & Fletcher, M.
Partner: UNT Libraries Government Documents Department

The efficacy of oxidative coupling for promoting in-situ immobilization of hydroxylated aromatics in contaminated soil and sediment systems. 1998 annual progress report

Description: 'Hydroxylated aromatic compounds (HAC''s) and their precursors are common contaminants of surface and subsurface systems at DOE facilities. The environmental fate and transport of such compounds, particularly in subsurface systems, is generally dominated by their sorption and desorption by soils and sediments. Certain secondary chemical reactions, most specifically abiotic and/or enzymatic oxidative coupling, may be significant in controlling the sorption and subsequent desorption of such hydroxylated aromatics by soils and sediments. The principal objectives of this study are to investigate: (1) the role of abiotic/enzymatic coupling reactions on the immobilization of HAC''s; (2) the effects of environmental factors on such immobilization; and (3) preliminary engineering approaches utilizing enhanced abiotic/enzymatic coupling reactions to immobilize hydroxylated aromatics in-situ. Information gathered from the study will be useful in quantifying the behavior of this class of organic compounds in various subsurface contamination scenarios relevant to DOE facilities, and in specifying strategies for the selection and design of remediation technologies. Over the first two years of this three-year project, the authors have developed a significantly improved understanding of the mechanisms of hydroxylated aromatic compound sorption and immobilization by natural soils and sediments. Immobilization in this context is attributed to oxidative coupling of the hydroxylated aromatics subsequent to their sorption to a soil or sediment, and is quantified in terms of the amount of a sorbed target compound retained by a sorbent after a series of sequential water and solvent extractions. The presence of oxygen, metal oxides, and organic matter, all of which can potentially catalyze/facilitate the abiotic oxidative coupling of HAC''s, were investigated during these first two years. Three different HAC''s: phenol, trichlorophenol and o-cresol were included in the experimental program. Inorganic soil matrices were represented by a glacial wash sand (Wurtsmith sand) having very low organic content. Because the chemical nature of soil organic ...
Date: June 1, 1998
Creator: Weber, W.J. & Bhandari, A.
Partner: UNT Libraries Government Documents Department