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Construction of bending magnet beamline at the APS for environmental studies. Progress report, September 1996--September 1997

Description: 'The items that were accomplished during this period are: (1) preparation and submission of the preliminary design report for the bending magnet beamline; (2) construction of the first optical enclosure (FOE) hutch for the BM beamline and ordering of the installation of utilities, in addition to the FOE hutch, the authors have started construction on the experimental hutch, although this is being supported by other funds; (3) the package has been ordered for the shutter assembly and monochromator for the bending magnet beamline, consisting of the monochromator, white beam stop, and bremstrahlung stop, all integrated on a table; (4) the beamline scientist for the bending magnet has been hired and is active on design and construction activities. In summary, the construction of the bending magnet beamline is proceeding as scheduled. The authors have obtained additional funding necessary to complete construction of the beamline and, according to the estimates, this additional funding plus the funding from the EMSP grant should allow us to complete construction of the bending magnet beamline during the three-year tenure of this grant.'
Date: January 1, 1997
Creator: Stern, E.A.
Partner: UNT Libraries Government Documents Department

Peptide Based Radiopharmaceuticals: Specific Construct Approach

Description: The objective of this project was to develop receptor based peptides for diagnostic imaging and therapy. A series of peptides related to cell adhesion molecules (CAM) and immune regulation were designed for radiolabeling with <sup>99m</sup>Tc and evaluated in animal models as potential diagnostic imaging agents for various disease conditions such as thrombus (clot), acute kidney failure, and inflection/inflammation imaging. The peptides for this project were designed by the industrial partner, Palatin Technologies, (formerly Rhomed, Inc.) using various peptide design approaches including a newly developed rational computer assisted drug design (CADD) approach termed MIDAS (Metal ion Induced Distinctive Array of Structures). In this approach, the biological function domain and the <sup>99m</sup>Tc complexing domain are fused together so that structurally these domains are indistinguishable. This approach allows construction of conformationally rigid metallo-peptide molecules (similar to cyclic peptides) that are metabolically stable in-vivo. All the newly designed peptides were screened in various in vitro receptor binding and functional assays to identify a lead compound. The lead compounds were formulated in a one-step <sup>99m</sup>Tc labeling kit form which were studied by BNL for detailed in-vivo imaging using various animals models of human disease. Two main peptides usingMIDAS approach evolved and were investigated: RGD peptide for acute renal failure and an immunomodulatory peptide derived from tuftsin (RMT-1) for infection/inflammation imaging. Various RGD based metallopeptides were designed, synthesized and assayed for their efficacy in inhibiting ADP-induced human platelet aggregation. Most of these peptides displayed biological activity in the 1-100 ┬ÁM range. Based on previous work by others, RGD-I and RGD-II were evaluated in animal models of acute renal failure. These earlier studies showed that after acute ischemic injury the renal cortex displays RGD receptor with higher density. The results have indicated good diagnostic potential for their use in this clinical situation, as an imaging agent to ...
Date: October 21, 1997
Creator: Som, P; Rhodes, B A & Sharma, S S
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

Comparison of the bioavailability of elemental waste laden soils using in vivo and in vitro analytical methodology and refinement of exposure/dose models. 1998 annual progress report

Description: 'The authors hypotheses are: (1) the more closely the synthetic, in vitro, extractant mimics the extraction properties of the human digestive bio-fluids, the more accurate will be the estimate of an internal dose; (2) performance can be evaluated by in vivo studies with a rat model and quantitative examination of a mass balance, calculation and dose estimates from model simulations for the in vitro and in vivo system; and (3) the concentration of the elements Pb, Cd, Cr and selected Radionuclides present in the bioavailable fraction obtained with a synthetic extraction system will be a better indicator of contaminant ingestion from a contaminated soil because it represents the portion of the mass which can yield exposure, uptake and then the internal dose to an individual. As of April 15, 1998, they have made significant progress in the development of a unified approach to the examination of bioavailability and bioaccessibility of elemental contamination of soils for the ingestion route of exposure. This includes the initial characterization of the soil, in vitro measurements of bioaccessibility, and in vivo measurements of bioavailability. They have identified the basic chemical and microbiological characteristics of waste laden soils. These have been used to prioritize the soils for potential mobility of the trace elements present in the soil. Subsequently they have employed a mass balance technique, which for the first time tracked the movement and distribution of elements through an in vitro or in vivo experimental protocol to define the bioaccessible and the bioavailable fractions of digested soil. The basic mass balance equation for the in vitro system is: MT = MSGJ + MIJ + MR. where MT is the total mass extractable by a specific method, MSGJ, is the mass extracted by the saliva and the gastric juices, MIJ is the mass extracted by the intestinal ...
Date: June 1, 1998
Creator: Lioy, P.J.; Gallo, M.; Georgopoulos, P.; Tate, R. & Buckley, B.
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

Atmospheric-pressure plasma cleaning of contaminated surfaces. 1998 annual progress report

Description: 'The object of this research program is to develop an atmospheric-pressure plasma jet for converting transuranic wastes (TRUs) into low-level radioactive wastes (LLWs). This plasma process will be used to efficiently decontaminate a wide range of structures and equipment. This report summarizes work after 1 year and 9 months of a 3-year project. A picture of the atmospheric-pressure plasma jet is shown in Fig. 1. This new plasma source consists of two concentric electrodes through which a mixture of helium and reactive gases flow. The plasma is ignited by applying 13.56 MHz RF power to the inner electrode. The characteristics of this discharge are different from other atmospheric-pressure plasmas, such as transferred arcs, torches, coronas and silent discharges. Shown in Fig. 2 is the current-voltage curve for the plasma jet. Spark breakdown occurs at 0.01 A, and is proceeded by a normal glow region, in which the voltage remains constant with increasing current, and an abnormal glow region, in which the voltage increases rapidly with current. At about 1.0 A and 225 V, the plasma begins to arc. The normal glow region is rarely observed in atmospheric pressure plasmas. They usually proceed directly from spark breakdown to arcing. The trend shown in the figure indicates that the plasma jet is stable over a wide range of operating conditions. The distribution of reactive species in a plasma jet, containing oxygen and helium, has been characterized by Langmuir probe measurements, optical emission spectroscopy, and ultraviolet absorption spectroscopy. The charged particle density ranges from about 5 x 10{sup 11} cm{sup -3} inside the plasma to 1 x 10{sup 10} cm{sup -3} in the jet exit. The concentration of metastable oxygen molecules (a 1 Dg and b 1 Sg{sup +} ) is estimated to be between 10{sup 12} to 10{sup 13} cm{sup -3} . ...
Date: June 1, 1998
Creator: Hicks, R.F. & Selwyn, G.
Partner: UNT Libraries Government Documents Department

Atmospheric pressure plasma cleaning of contamination surfaces. 1997 mid-year progress report

Description: 'Goals of the project are to (1) identify the key physics and chemistry underlying the use of high pressure plasmas for etching removal of actinides and actinide surrogates; and (2) identify key surface reactions and plasma physics necessary for optimization of the atmospheric pressure plasma jet. Technical description of the work decommissioning of transuranic waste (TRU) into low-level radioactive waste (LLW) represents the largest cleanup cost associated with the nuclear weapons complex. This work is directed towards developing a low-cost plasma technology capable of converting TRU into LLW, based upon highly selective plasma etching of plutonium and other actinides from contaminated surfaces. In this way, only the actinide material is removed, leaving the surface less contaminated. The plasma etches actinide material by producing a volatile halide compound, which may be efficiently trapped using filters. To achieve practical, low-cost operation of a plasma capable of etching actinide materials, the authors have developed a y-mode, resonant-cavity, atmospheric pressure plasma jet (APPJ). In contrast to conventional, low pressure plasmas, the APPJ produces a purely-chemical effluent free of ions, and so achieves very high selectivity and produces negligible damage to the surface. Since the jet operates outside a chamber, many nuclear wastes may be treated including machinery, duct-work, concrete and other building materials. In some cases, it may be necessary to first remove paint from contaminated surfaces using a plasma selective for that surface, then to switch to the actinide etching chemistry for removal of actinide contamination. The goal of this work is to develop the underlying science required for maturation of this technology and to establish early version engineering prototypes. Accomplishments to Date The authors have made significant progress in this program. The work conducted jointly at Los Alamos and at UCLA. This has been facilitated by exchange of people, equipment and designs ...
Date: June 1, 1997
Creator: Selwyn, G.S. & Hicks, R.
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

Bioavailability of organic solvents in soils: Input into biologically based dose-response models for human risk assessments. 1998 annual progress report

Description: 'The purpose of this study is to determine the bioavailability of organic solvents following dermal exposures to contaminated soil and water. Breath analysis is being used to obtain real-time measurements of volatile organics in expired air following exposure in rats and humans. Rhesus monkeys will be used as surrogates for humans in benzene exposures. The exhaled breath data is being analyzed using physiologically based pharmacokinetic (PBPK) models to determine the dermal bioavailability of organic solvents under realistic exposure conditions. The end product of this research will be a tested framework for the rapid screening of real and potential exposures while simultaneously developing physiologically based pharmacokinetic (PBPK) models to comprehensively evaluate and compare exposures to organics from either contaminated soil or water. This report summarizes work 7 months into a 3-year project. Method development has produced systems for solvent exposure from soil and water which mimic actual exposure, and for which animals and human volunteers can be safely tested. Soil exposure is generally open to the air (working the soil) while water exposure is generally immersion. For 6--8 hour test exposure, a patch has been developed where soil is contained against the skin by a non-occlusive membrane, while simultaneously allowing volatilization of test solvent to the environment (activated charcoal). The water counterpart is an occlusive glass culture dish, sealed to skin with silicone adhesive. Shorter term exposure is done by one hand immersion in a bucket containing circulating water or soil, the volunteer instructed to move fingers through the water or soil. Human volunteers and animals breathe fresh air via a new breath-inlet system that allows for continuous real-time analysis of undiluted exhaled air. The air supply system is self-contained and separated from the exposure solvent-laden environment. The system uses a Teledyne 3DQ Discovery ion trap mass spectrometer (MS/MS) equipped with ...
Date: June 1, 1998
Creator: Wester, R.C. & Maibach, H.I.
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

Chemical speciation of strontium, americium, and curium in high level waste: Predictive modeling of phase partitioning during tank processing. 1998 annual progress report

Description: 'In this research program, Pacific Northwest National Laboratory (PNNL) and Florida State University (FSU) are investigating the speciation of Sr and Am/Cm in the presence of selected organic chelating agents (ethylenediaminetetraacetic acid (EDTA), N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), nitrilotriacetic acid (NTA), and iminodiacetic acid (IDA)) over ranges of hydroxide, carbonate, ionic strength, and competing metal ion concentrations present in high level waste tanks. The fundamental understanding of chemical speciation reactions gained from these studies is also used to propose methodologies for removal of Sr and Am/Cm from organic chelates present in high level tank waste, via competition, displacement or other reactions, without the need for the development of costly and potentially hazardous organic destruction technologies.'
Date: June 1, 1998
Creator: Felmy, A. R.
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

Characterization of a new family of metal transport proteins. 1998 annual progress report

Description: 'Soils at many DOE sites are contaminated with metals and radionuclides. Such soils obviously pose a risk to human and animal health. Unlike organic wastes which can be metabolized, metals are immutable and cannot be degraded into harmless constituents. Phytoremediation, the use of plants to remove toxic materials from soil and water, may prove to be an environmentally friendly and cost effective solution for cleaning up metal-contaminated sites. The success of phytoremediation will rely on the availability of plants that absorb, translocate, and tolerate the contaminating metals. However, before the authors can engineer such plants, they need more basic information on how plants acquire metals. An important long term goal of the research program is to understand how metals such as zinc, cadmium and copper are transported across membranes. The research is focused on a new family of metal transporters which they have identified through combined studies in the yeast Saccharomyces cerevisiae and in the model plant Arabidopsis thaliana. They have identified a family of 19 presumptive metal transport genes in a variety of organisms including yeast, trypanosomes, plants, nematodes, and humans. This family, which the authors have designated the ZIP genes, provides a rich source of material with which to undertake studies on metal transport in eukaryotes. The project has three main objectives: Objective 1: Determine the sub-cellular location of the ZIP proteins in Arabidopsis. Objective 2: Carry out a structure/function analysis of the proteins encoded by the ZIP gene family to identify regions of the protein responsible for substrate specificity and affinity. Objective 3: Engineer plants to overexpress and underexpress members of the ZIP gene family and analyze these transgenic plants for alterations in metal accumulation. They now know that manipulation of transporter levels will also require an understanding of post-transcriptional control of ZIP gene expression. They are ...
Date: June 1, 1998
Creator: Guerinot, M.L.
Partner: UNT Libraries Government Documents Department

Mechanism involved in trichloroethylene-induced liver cancer: Importance to environmental cleanup. 1997 annual progress report

Description: 'The Pacific Northwest National Lab. was awarded ten (10) Environmental Management Science Program (EMSP) research grants in Fiscal Year 1996. This section gives a summary of how each grant is addressing significant DOE cleanup issues, including those at the Hanford Site. The technical progress made to date in each of these research projects is addressed in more detail in the individual progress reports contained in this document. This research is primarily focused in three areas-Tank Waste Remediation, Soil and Groundwater Cleanup, and Health Effects.'
Date: June 1, 1997
Creator: Bull, R.J.
Partner: UNT Libraries Government Documents Department

Mechanism involved in trichloroethylene-induced liver cancer: Importance to environmental cleanup. 1998 annual progress report

Description: 'The objective of this project is to develop critical data for changing risk-based clean-up standards for trichloroethylene (TCE). The project is organized around two interrelated tasks: Task 1 addresses the tumorigenic and dosimetry issues for the metabolites of TCE that produce liver cancer in mice, dichloroacetate (DCA) and trichloroacetate (TCA). Early work had suggested that TCA was primarily responsible for TCE-induced liver tumors, but several, more mechanistic observations suggest that DCA may play a prominent role. This task is aimed at determining the basis for the selection hypothesis and seeks to prove that this mode of action is responsible for TCE-induced tumors. This project will supply the basic dose-response data from which low-dose extrapolations would be made. Task 2 seeks specific evidence that TCA and DCA are capable of promoting the growth of spontaneously initiated cells from mouse liver, in vitro. The data provide the clearest evidence that both metabolites act by a mechanism of selection rather than mutation. These data are necessary to select between a linear (i.e. no threshold) and non-linear low-dose extrapolation model. As of May of 1998, this research has identified two plausible modes of action by which TCE produces liver tumors in mice. These modes of action do not require the compounds to be mutagenic. The bulk of the experimental evidence suggests that neither TCE nor the two hepatocarcinogenic metabolites of TCE are mutagenic. The results from the colony formation assay clearly establish that both of these metabolites cause colony growth from initiated cells that occur spontaneously in the liver of B 6 C 3 F 1 mice, although the phenotypes of the colonies differ in the same manner as tumors differ, in vivo. In the case of DCA, a second mechanism may occur at a lower dose involving the release of insulin. This observation ...
Date: June 1, 1998
Creator: Bull, R.J.; Thrall, B.D.; Sasser, L.B.; Miller, J.H. & Schultz, I.R.
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