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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

Environmental analysis of endocrine disrupting effects from hydrocarbon contaminants in the ecosystem. 1998 annual progress report

Description: 'The objective of this project is to determine how environmental contaminants, namely hydrocarbons, can act as hormones or anti-hormones (i.e., environmental hormones) in different species present in aquatic ecosystems. Species of particular focus are those which can serve as sentinel species (e.g., amphibians) and, thus, provide early warning signals for more widespread impacts on an ecosystem and its wildlife and human inhabitants. This reports the progress of 1.5 years of a three-year grant awarded to the Tulane/Xavier Center for Bioenvironmental Research (CBR). A growing body of evidence suggests that chemicals in the environment can disrupt the endocrine system of animals (i.e., wildlife and humans) and adversely impact the development of these species. Because of the multitude of known endocrine-disrupting chemicals and the numerous industrial and government sectors producing these chemicals, almost every federal agency has initiated research on the endocrine effects of chemicals relevant to their operations. This study represents the Department of Energy (DOE) Basic Energy Sciences'' only research on the impacts of endocrine-disrupting chemicals. The activities employed by this project to determine these impacts include development of biotechnology screens (in vitro), animal screens (in vivo), and other analyses of aquatic ecosystem biomarkers of exposure. The results from this study can elucidate how chemicals in the environment, including those from DOE activities, can signal (and alter) the development of a number of species in aquatic ecosystems. These signals can have detrimental impacts not only on an organismal level, but also on community, population, and entire ecosystem levels, including humans.'
Date: June 1, 1998
Creator: McLachlan, J.
Partner: UNT Libraries Government Documents Department

Modeling of cation binding in hydrated 2:1 clay minerals. Progress report, September 15, 1996--September 14, 1997

Description: 'The primary focus of the research is the development of molecular theories of ion binding to clay minerals, with a view toward understanding the mechanism of radionuclide transport through soils. The overall aim of the research and the computational methods employed are essentially unchanged from those originally proposed. The research is split conceptually into three phases, based on the radionuclides considered. The first, cesium phase has an estimated completion time of 1.5 years from the project initiation. This phase is ongoing at this time. The second, strontium and third, uranium phases will be addressed in the second half of the project period. Phase 1 Accomplishments Code Development: A computer simulation code for the treatment of hydrated smectite and vermiculite clays with varying water content has been developed. This version of the code enables calculations under conditions of constant interlayer spacing or constant applied pressure, and for the complete series of interlayer alkali-metal ions. Final development of the code for (i), calculations of exchange free energies, and (ii), calculations at constant water chemical potential should be completed within the next month. This will allow the most important scientific issues of phase 1 to be fully addressed. Hydrated Clay Structure: The molecular structures of Cs{sup +}- and Na{sup +}-montmorillonite (a common swelling clay) have been investigated. The observed layer spacings versus water content of both clays agree well with experimental swelling curves. 1,2 This has provided validation of the simulation models. Comparison of cesium and sodium structures indicate that cesium preferentially forms inner-sphere complexes with the clay surface. The relationship of this structural observation to Na{sup +} Cs{sup +} exchange thermodynamics is presently under investigation. Dry Cs{sup +}-Montmorillonite Structure: It is thought that dry, cesium-substituted montmorillonites exist as mixed-layer structures with both symmetrical (hexagonal cavities overlapping) and non-symmetrical (hexagonal cavities shifted) stacking ...
Date: January 1, 1997
Creator: Smith, D.E.
Partner: UNT Libraries Government Documents Department

In-situ spectroelectrochemical studies of radionuclide contaminated surface films on metals and the mechanism of their formation and dissolution. 1997 annual progress report

Description: 'The incorporation of radioactive contaminants into corrosion product scales on metals is being investigated using in-situ spectroscopic and electrochemical techniques. To facilitate the study, stable isotopes are used initially, while the corrosion films are simulated by electrodeposition of the appropriate oxide (hydroxide) onto a graphite substrate. Synchrotron x-ray absorption spectroscopy (XAS) is used to determine the structure and composition of the host oxide film, as well as the local structure of the impurity ion. Results on the incorporation of Sr and Ce into surface films of Ni(OH){sub 2} and NiOOH are reported. Cathodically deposited Ni(OH){sub 2} was found to be mainly in the {alpha} form while anodically prepared NiOOH consists of Ni{sup +2} and Ni{sup +4} phases. Sr in the films consists mainly of Sr{sup 2+} which appears to be coordinated to oxygen atoms and is likely to exist as small domains of co-precipitated material. Ce in Ni(OH){sub 2} exists mainly as Ce{sup +3} and as a Ce{sup +4} species when co-deposited with NiOOH. The structure of the Ce{sup +4} phase appears similar to a Ce(OH){sub 4} standard. However, x-ray diffraction and laser Raman measurements indicate that the latter chemical formulation is probably incorrect and that the material is more likely to be a disordered hydrous cerium oxide. Ce chemisorbed on Ni(OH){sub 2} and NiOOH films is predominantly in the +3 valency state. Iron oxide films prepared by anodic deposition from borate buffer solution containing Fe{sup +2}, has been found by XAS to consist mainly of {alpha} FeOOH. The latter has been found by others to be the constituent of the corrosion film on iron; this lends credence to the present simulation approach. Future work will involve studies on the incorporation of radioactive Sr, Ce, and Cs, as well as U, into nickel and iron oxide films. Investigations on the ...
Date: September 1, 1997
Creator: Melendres, C.A.; Balasubramanian, M.; Papapanayiotou, D.; Mini, S. & Mansour, A.N.
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

Radionuclide immobilization in the phases formed by corrosion of spent nuclear fuel: The long-term assessment. 1998 annual progress report

Description: 'This research program is designed to identify the long-term corrosion products of naturally occurring UO{sub 2}{sup 2+} under oxidizing conditions as an analogue for corrosion of UO2 in spent nuclear fuel. This work will identify the phases that form, the reaction path during their formation, their stability, and their ability to incorporate key radionuclides. As of May 1998, this report summarizes work that has been completed during the first seven months of a 3 year research program. During this period, a post-doctoral fellow, F. Chen, has focused his efforts on the development of a theoretical basis for predicting the Gibbs free energies and enthalpies of formation of uranium (VI) phases. This is quite important, as these uranyl phases are the important alteration products that form during the corrosion of UO{sub 2}. The thermodynamic data base for these uranyl phase is extremely limited and often contradictory.'
Date: June 1, 1998
Creator: Ewing, R.C.
Partner: UNT Libraries Government Documents Department

Molecular dissection of the cellular mechanisms involved in nickel hyperaccumulation. 1997 annual progress report

Description: 'Phytoremediation, the use of plants for environmental cleanup of pollutants, including toxic metals, holds the potential to allow the economic restoration of heavy metal and radionuclide contaminated sites. A number of terrestrial plants are known to naturally accumulate high levels of metals in their shoots (1--2% dry weight), and these plants have been termed metal-hyperaccumulators. Clearly, the genetic traits that determine metal-hyperaccumulation offers the potential for the development of practical phytoremediation processes. The long-term objective is to rationally design and generate plants ideally suited for phytoremediation using this unique genetic material. Initially, the strategy will focus on isolating and characterizing the key genetic information needed for expression of the metal-hyperaccumulation phenotype. Recently, histidine has been shown to play a major role in Ni hyperaccumulation. Based on this information the authors propose to investigate, at the molecular level, the role of histidine biosynthesis in Ni hyperaccumuIation in Thlaspi goesingense, a Ni hyperaccumulator species.'
Date: October 28, 1997
Creator: Salt, D. E.
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

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

Permanganate treatment of DNAPLs in reactive barriers and source zone flooding schemes. 1997 annual progress report

Description: 'The goals of this study are (1) to elucidate the basic mechanisms by which potassium permanganate oxidizes common chlorinated solvents, various constituents in aqueous solution, and porous-medium solids, and (2) to assess the potential for chemical oxidation by potassium permanganate to serve as a remedial scheme involving either source zone flooding or reactive barriers. The research plan involves a combined experimental/modeling study that builds on the extensive previous work in the area of reactive barrier systems, and modeling of reactive contaminant transport. The experimental studies are being undertaken at The Ohio State University by Dr. Schwartz and his co-workers. The modeling work is being conducted in Albuquerque, NM by Dr. Zhang of Intera, Inc. The workplan for this study is designed around the following four objectives (1) to describe through batch experiments the kinetics and mechanisms by which potassium permanganate oxidizes dissolved tetrachloroethene (PCE), trichloroethene (TCE), and dichloroethene (DCE), (2) to examine using column studies the nature and kinetics of reactions between potassium permanganate, residual DNAPLs (PCE, TCE, and DCE) and porous medium solids, (3) to represent the process understanding in flow and transport models that demonstrate the potential applicability of the approach, and (4) to apply the resulting computer code in the development of appropriate field tests for assessing the approach.'
Date: January 1, 1997
Creator: Schwartz, F.W.
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

In-situ characterizations of dense non-aqueous phase liquids using partitioning tracers. Annual progress report, September 15, 1996--September 14, 1997

Description: 'This paper describes laboratory research conducted to investigate the use of partitioning tracers for the detection, volume estimation, and remediation performance assessment of vadose zones contaminated by nonaqueous phase liquids (NAPLs). These laboratory studies used Ottawa sand and field soil packed columns. The columns were saturated, then reduced to residual saturations of water and NAPL, creating a three phase system of air, water, and NAPL. Conservative and partitioning gas tracers were injected into the column and their elutions were analyzed. The method of moments was used to estimate partition coefficients between the air and NAPL phases for each of the tracers. The partition coefficients and retardation factors are used to select appropriate tracers for NAPL detection and volume estimation in the field. This research identified several perfluorocarbon tracers suitable for use in the field and demonstrated the feasibility of using partitioning tracers as a tool for NAPL detection and volume estimation in the vadose zone.'
Date: January 23, 1998
Creator: Pope, G.A.; McKinney, D.C.; Gupta, A.D.; Jackson, R.E. & Jin, M.
Partner: UNT Libraries Government Documents Department

Experimental determination of contaminant metal mobility as a function of temperature time and solution. 1998 annual progress report

Description: 'The objective of this work is to determine the fundamental data needed to predict the behavior of {sup 90}Sr at temperature and time scales appropriate to thermal remediation. The authors approach combines macroscopic sorption/precipitation and desorption/dissolution kinetic experiments which track changes in solution composition with direct molecular characterization of Sr in the solid phase using x-ray absorption spectroscopy. These experiments will be used to identify mechanistic geochemical reactions and their thermochemical properties that will be incorporated into geochemical computer codes. As of May 1998, the authors have completed most of the static sorption experiments as a function of temperature (25, 60, and 80 C), solution pH (4 to 10), initial Sr concentrations (10{sup -7} to 10{sup -3} M), and partial pressure of CO 2 (100% N 2 or atmospheric CO 2 ). They chose to study goethite, kaolinite, gibbsite, and amorphous silica because iron and aluminum (oxy)hydroxides, aluminosilicate clays, and quartz are key components in soils, sediments, and aquifers. The authors have completed x-ray absorption analysis of Sr sorption to kaolinite and goethite at 25{sup -}C, initial Sr of 10{sup -}3 M, and pH 9.'
Date: June 1, 1998
Creator: Carroll, S.; Bruton, C.; O'Day, P. & Sahai, N.
Partner: UNT Libraries Government Documents Department

Molecular characterization of a novel heavy metal uptake transporter from higher plants and its potential for use in phytoremediation. 1998 annual progress report

Description: 'Soils and waters contaminated with high levels of heavy metals such as Cadmium, Lead and Copper are detrimental to human and environmental health. Many human disorders have been attributed to environmental contamination by heavy metals. Removal of heavy metals from highly contaminated sites is therefore a very costly but necessary process that is currently being pursued. Recent research in several laboratories indicates that uptake of heavy metals into plants via the root system may provide a cost-effective approach for decontamination of certain heavy metal-laden soils and waters. Several mechanisms have been identified, which allow detoxification in the cytosol and vacuoles of plants. However, the molecular biological mechanisms by which heavy metals are transported from soils across the plasma membrane into roots have remained largely unknown. In recent research, the laboratory has cloned a cation uptake transporter cDNA from plants. Yeast cells expressing this cDNA show enhanced uptake of calcium and cadmium. The proposed research is testing the transport of toxic and nutrient metals by the encoded protein.'
Date: June 1, 1998
Creator: Schroeder, J.I.
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

Plant rhizosphere effects on metal mobilization and transport. 1998 annual progress report

Description: 'Information on the mechanism of how plants mobilize, uptake, and metabolize metal ions is very limited. Especially deficient is the understanding of these processes involving pollutant metal ions and interactions among these ions. Based on the current knowledge regarding nutrient ions, it is clear that elucidation of rhizospheric processes such as exudation of organic ligands by plant roots and plant metabolism/adaptation involving these biogenic chelators is critically important. A mechanistic insight into these processes will advance knowledge in microbe-plant host interactions and how metal ions are mobilized, immobilized, and sequestered by these interactions. This, in turn, is essential to applications such as phytobioremediation and microbioremediation of metal ion pollution. Root exudation also serves many other important rhizosphere functions including energy supply for microbial degradation of organic pollutants, structuring of microbial community, and the formation of soil humic materials which are considered to be a major sink for both organic and inorganic pollutants. How root exudates function is critically dependent on the chemical nature of exudate components. Therefore, a comprehensive characterization of all major exudate components, regardless of their chemical class, should facilitate the development and implementation of bioremediation for both organic and inorganic pollutants. Therefore, the objectives of this project are: (1) To obtain a comprehensive composition of major organic components in plant root exudates as a function of different metal ions; (2) To examine plant metabolic response(s) to these metal ion treatments, with emphasis on biosynthetic pathways of organic ligands; and (3) To investigate the effect(s) of soil microbial (e.g. mycorrhizae) association on (1) and (2).'
Date: June 1, 1998
Creator: Fan, T.W.M.
Partner: UNT Libraries Government Documents Department

Control of biologically active degradation zones by vertical heterogeneity: Applications in fractured media. 1998 annual progress report

Description: 'The objective of this research is to determine the relationship between biologically active contaminant degradation zones in a fractured, subsurface medium and vertical geological heterogeneities. The research is being performed on samples collected from the Test Area North (TAN) site at the Idaho National Engineering and Environmental Laboratory (INEEL) where a dissolved trichloroethylene (TCE) plume is migrating in the basalts and interbed sediments of the Eastern Snake River Plain (ESRP) aquifer. Results are leading to an enhanced understanding of the constraints placed on the activities and distribution of TCE-degrading organisms by the geochemical and hydrological environment. This understanding allows better decisions to be made regarding the use of remedial technologies such as natural attenuation and in-situ bioremediation at geologically complex waste sites. Through this research, investigations conducted by the DOE Subsurface Science Program at TAN have been extended in order to develop a mechanistic understanding of the coupled geomicrobial and hydrogeochemical processes that are necessary to predict field-scale intrinsic degradation rates of TCE. The research objective is being accomplished by characterizing paired cores and water samples from boreholes located in differing geochemical and flow environments within the plume. Analysis of these samples will allow the determination of the spatial correlation between microbial degradation and preferred flow paths for the contaminant and required electron donors and acceptors. A combination of traditional microbiological methods (e.g., enrichments) and molecular tools are being used to characterize the indigenous microbial communities. This report summarizes work conducted after 1.5 years of a three year project.'
Date: June 1, 1998
Creator: Colwell, F.S.; Smith, R.; McKinley, J.P.; Fredrickson, J.K.; Onstott, T.C. & Reysenbach, A.L.
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

Rapid mass spectrometric DNA diagnostics for assessing microbial community activity during bioremediation. 1998 annual progress report

Description: 'Biological activity has often been attributed to changes in pollutant profiles found in contaminated soils when abiotic processes actually caused pollutant removal. Careful evaluation of bioremediation necessitates that all transformation and removal pathways are anticipated so that the pathways are controlled or monitored. The author''s work is directed at evaluating a monitoring strategy that relies on the combined use of DNA diagnostic procedures and mass spectrometry as the detection scheme. The intent is to track bioremediation by measuring the occurrence of genes in soil samples that are known to code for enzymes capable of degrading specific pollutants. Matrix-assisted-laser-desorption- ionization time-of-flight mass spectrometry (MALDI-TOF-MS) offers the possibility for automation and high throughput PNA detection as is needed to track the course of bioremediation over large polluted areas.'
Date: June 1, 1998
Creator: Benner, W.H.
Partner: UNT Libraries Government Documents Department

Environmentally-induced malignancies: An in vivo model to evaluate the health impact of chemicals in mixed waste. 1997 annual progress report

Description: 'Occupational or environmental exposure to organic ligands, solvents, fuel hydrocarbons, and polychlorinated biphenyls is linked to increased risk of developing leukemia, a blood cancer. The long term health effects of exposure to complex mixtures of chemicals and radionuclides are of particular concern because their biologic effects may synergize to increase risk of malignancy. Increased understanding of steps in the progression pathway of a normal cell to a cancer cell is important for biomonitoring, risk assessment and intervention in exposed individuals. Leukemias are characterized by multiple genetic aberrations. Accumulation of multiple genomic changes may reflect genomic instability in the affected ceils. Thus agents that induce DNA damage or genomic instability may increase accumulation of genomic alterations, thereby predisposing cells to transformation. However, not all DNA damaging agents predispose to transformation. Other factors such as genetic susceptibility, cell and tissue response to genotoxicity and cytotoxicity, DNA repair, etc. will impact malignant progression. The author proposed a progression model (Figure 1) of environmentally-induced leukemia that can be evaluated using mouse models.'
Date: January 1, 1997
Creator: Pallavicini, M.
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

Heavy metal pumps in plants. 1997 annual progress report

Description: 'Plants have been proposed as a bioremediation tool to help remove toxic heavy metals from contaminated land and water. However, little is known about how plants take up heavy metals from the soil and transport them to different parts of the plant. An important long term goal is to understand how heavy metals, such as copper and cadmium, are transported across the plasma membrane of plant cells. The proposed research is focused on a putative heavy metal uptake pump, AXA2p [Arabidopsis X (unknown heavy metal) ATPase, isoform 2 protein], identified in a model plant, Arabidopsis. AXA belongs to a super-family of ion-translocating P-type ATPases and is the first heavy metal pump cloned from plants. AXA2 is most similar to a subfamily of pumps recently identified in bacteria, yeast and humans which appear to pump heavy metals such as copper and cadmium. Three specific aims are proposed: (1) Determine the ion specificity of the AXA2 pump, (2) Determine how pumping activity is regulated, and (3) Determine if an increased uptake of specific heavy metals can be achieved by engineering a transgenic plant with a hyper-active pump. The hypothesis being tested is that AXA2 encodes a high affinity uptake pump for copper, with lower affinity for metals such as cadmium, zinc and nickel. Fundamental research on heavy metal transporters may eventually permit transgenic plants to be engineered with specific heavy metal uptake systems useful for bioremediation. The long term goal of the proposed research is to understand how heavy metals, such as copper and cadmium, are taken up from the soil and translocated throughout the plant. The focus is on a putative heavy metal pump, AXA2p [Arabidopsis X (unknown heavy metal) ATPase, isoform 2 protein], identified in a model plant, Arabidopsis. AXA2 belongs to a large family of ion-translocating P-type ATPases. AXA2p ...
Date: January 1, 1997
Creator: Harper, J.F.
Partner: UNT Libraries Government Documents Department

Rapid mass spectrometric DNA diagnostics for assessing microbial community activity during bioremediation. 1997 annual progress report

Description: 'The effort of the past year''s activities, which covers the first year of the project, was directed at developing DNA-based diagnostic procedures for implementation in high through-put analytical instrumentation. The diagnostic procedures under evaluation are designed to identify specific genes in soil microorganisms that code for pollutant-degrading enzymes. Current DNA-based diagnostic procedures, such as the ligase chain reaction (LCR) and the polymerase chain reaction (PCR), rely on gel electrophoresis as a way to score a diagnostic test. The authors are attempting to implement time-of-flight (TOF) mass spectrometry as a replacement for gel separations because of its speed advantage and potential for sample automation. The authors anticipate that if TOF techniques can be implemented in the procedures, then a very large number of microorganisms and soil samples can be screened for the presence of specific pollutant-degrading genes. The use of DNA-based procedures for the detection of biodegrading organisms or genes that code for pollutant-degrading enzymes constitutes a critical technology for following biochemical transformation and substantiating the impact of bioremediation. DNA-based technology has been demonstrated to be a sensitive technique for tracking micro-organism activity at the molecular level. These procedures can be tuned to identify groups of organisms, specific organisms, and activity at the molecular level. They are developing a P-monitoring strategy that relies on the combined use of DNA diagnostics with mass spectrometry as the detection scheme. The intent of this work is a two-fold evaluation of (1) the feasibility of replacing the use of gel separations for identifying polymerase chain reaction (PCR) products with a rapid and automatable form of electrospray mass spectrometry and (2) the use of matrix-assisted-laser-desorption-ionization mass spectrometry (MALDI-MS) as a tool to score oligonucleotide ligation assays (OLA).'
Date: January 1, 1997
Creator: Benner, W.H. & Hunter-Cevera, J.
Partner: UNT Libraries Government Documents Department