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Changes in pollutant profiles observed in contaminated soils have been attributed to biological activity when in actuality abiotic processes caused pollutant removal.1 This sometimes casual implication of biodegradation is not acceptable, but understandable, because factors which cause the disappearance of pollutants are not always easy to identify. Several pollutant removal or transformation pathways are possible with most pollutants found in soil and these processes may or may not operate independently. Careful evaluation of bioremediation necessitates that all transformation and removal pathways are anticipated so that the pathways are either controlled or monitored but in practice this is generally not possible. The diminution in pollutant oxidation might track with several candidate loss mechanisms and when this occurs the real cause becomes problematic to pin point. Many factors disguise or prevent the effectual tracking of bioremediation processes among which are three general types of problems: (1) The estimate that only about 0.1% or less of the microorganisms living in soils are culturable leads to the conclusion that the possibility for unknown organisms participating in a biodegradation pathway is high. How should these imperceptible microorganisms be tracked? (2) The diversity of the microcosm is large, yet several different genera have been shown to …

Changes in pollutant profiles observed in contaminated soils have been attributed to biological activity when in actuality abiotic processes caused pollutant removal.1 This sometimes casual implication of biodegradation is not acceptable, but understandable, because factors which cause the disappearance of pollutants are not always easy to identify. Several pollutant removal or transformation pathways are possible with most pollutants found in soil and these processes may or may not operate independently. Careful evaluation of bioremediation necessitates that all transformation and removal pathways are anticipated so that the pathways are either controlled or monitored but in practice this is generally not possible. The diminution in pollutant oxidation might track with several candidate loss mechanisms and when this occurs the real cause becomes problematic to pin point. Many factors disguise or prevent the effectual tracking of bioremediation processes among which are three general types of problems: (1) The estimate that only about 0.1% or less of the microorganisms living in soils are culturable leads to the conclusion that the possibility for unknown organisms participating in a biodegradation pathway is high. How should these imperceptible microorganisms be tracked? (2) The diversity of the microcosm is large, yet several different genera have been shown to …

Carbon tetrachloride has been used extensively within the DOE nuclear weapons facilities. Rocky Flats was formerly the largest volume consumer of CCl4 in the United States using 5000 gallons in 1977 alone (Ripple, 1992). At the Hanford site, several hundred thousand gallons of CCl4 were discharged between 1955 and 1973 into underground cribs for storage. Levels of CCl4 in groundwater at highly contaminated sites at the Hanford facility have exceeded 8 the drinking water standard of 5 ppb by several orders of magnitude (Illman, 1993). High levels of CCl4 at these facilities represent a potential health hazard for workers conducting cleanup operations and for surrounding communities. The level of CCl4 cleanup required at these sites and associated costs are driven by current human health risk estimates, which assume that CCl4 is a genotoxic carcinogen. The overall purpose of these studies was to improve the scientific basis for assessing the health risk associated with human exposure to CCl4. Specific research objectives of this project were to: (1) compare the rates of CCl4 metabolism by rats, mice and hamsters in vivo and extrapolate those rates to man based on parallel studies on the metabolism of CCl4 by rat, mouse, hamster and human …

MORE is a consortium of educational, governmental, and industrial partners in cooperation with the state's Tribal colleges. Formed in 1994, the objectives are to develop and promote energy-related research and education in the state of Montana and the Northwestern region. Specifically, they set out to: (1) promote collaboration and cooperation among Montana's Colleges and Universities; (2) maximize use of existing personnel and resources; (3) foster partnerships with industries, state agencies, and tribal nations; and (4) enhance energy research and training. The 1st Implementation Grant consisted of Management and Coordination, Human Outreach, and two Research Clusters Petroleum Reservoir Characterization and Wind Energy. Overall, they consider this program to have been highly successful. That conclusion was mirrored by the DOE site reviewers, and by invitations from Dr. Matesh Varma, the DOE/EPSCoR National Program Director, to present their programs and outcomes as models for other states the National DOE/EPSCoR meetings.

The objective of this project is to develop the scientific basis for hydrothermal separation of chromium from High Level Waste (HLW) sludges. Our worked is aimed at attaining a fundamental understanding of chromium speciation, oxidation/reduction and dissolution kinetics, reaction mechanisms, and transport properties under hydrothermal conditions in both simple and complex salt solutions that will ultimately lead to an efficient chromium leaching process.

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.

During the FY96-FY99 funding cycle we examined the uptake of aqueous strontium onto goethite, kaolinite, and amorphous silica surfaces as a function of pH, total strontium, and temperature. Our overall goal was to produce a mechanistic sorption model that can be used in reaction-transport calculations to predict the mobility and attenuation of radioactive strontium (90Sr) in the environment. Our approach was to combine structural information derived from synchrotron-based x-ray absorption spectroscopic analysis together with macroscopic uptake data and surface complexation models to clarify the physical and chemical structure of sorbed complexes. We chose to study these solids because of the prevalence of clays and iron hydroxides in natural systems, and because silica colloids probably form beneath leaking tanks at Hanford as caustic waste is neutralized. We have published the spectroscopic work in two papers in the Journal of Colloid and Interface Science [1, 2], and will soon submit at third manuscript to Geochemical Transactions [3] combining the sorption and spectroscopic data with a mechanistic complexation model.

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.

Semiweekly newspaper from Sealy, Texas that includes local, state, and national news along with advertising.

Photocatalysis could provide a cost-effective route to recycle CO{sub 2} to useful chemicals or fuels. Development of an effective catalyst for the photocatalytic synthesis requires (i) the knowledge of the surface band gap and its relation to the surface structure, (ii) the reactivity of adsorbates and their reaction pathways, and (iii) the ability to manipulate the actives site for adsorption, surface reaction, and electron transfer. The research tasks accomplished during first six months include setting up a photo-catalytic reactor, optical bench, calibration of gas chromatograph, catalyst preparation, and catalyst screening study. Addition of Pt and Cu on TiO{sub 2} was found to increase the activity of TiO{sub 2} catalysts for the synthesis of methanol and methane. The most active catalysts obtained from this study will be used for mechanistic study. The overall goal of this research is to provide a greater predictive capability for the design of visible light-photosynthesis catalysts by a deeper understanding of the reaction kinetics and mechanism as well as by better control of the coordination/chemical environment of active sites.

The purpose of this project was to explore and refine applications of isotope measurements for guiding environmental remediation strategies. The isotopic compositions of samples from field sites were analyzed to address both basic scientific issues and site-specific problems. Initial efforts were concentrated on two sites at the Idaho National Engineering and Environmental Laboratory (INEEL). During the final year of the project, the focus of work was shifted to the Hanford site in Washington. The Test Area North (TAN) site at INEEL consists of a 2 km-long plume of mixed wastes containing low-level radionuclides, sewage and chlorinated solvents that were injected into the groundwater between 1955 and 1972. Isotopic measurements of groundwater samples were made to address questions about the source of the groundwater and the regional hydrology at TAN. These data show that there is a significant input to the groundwater from playa lakes that were located west of the TAN site prior to the 1950s (since that time, inflow to the playas has been diverted for agricultural uses). Radiocarbon dates of the playa waters indicate a mean infiltration rate of 3-5 cm/year. These results explain the groundwater flow patterns observed in the plume and provide constraints on transport rates.

This program (EMSP Project No.60424) was funded by the EM Science Program for the development of an integrated mass spectrometric analysis system (see Figure 1.) capable of analyzing materials from room up to high temperatures, with the practical upper temperature limit to be experimentally determined. A primary objective of the program was the development of techniques to analyze waste materials during vitrification processing to produce waste forms. The sample is heated in the ion formation region of the mass spectrometer. This instrument geometry allows the atoms and molecules that volatilize from the sample as neutrals to be ionized before they have a chance to condense on surfaces that generally are cooler that the sample. In addition, this geometry facilitates more efficient focusing of SIMS and thermal ions into the quadrupole mass analyzer. Instrumental capabilities include the detection of volatilizing neutral species by electron bombardment, ions forming on the surface by surface ionization, and surface species by static SIMS. In addition, the instrument has elemental analysis capability (by dynamic SIMS).

The goals of this program have been to develop a series of new compounds that act as redox recyclable heavy metal ion selective materials. This has been a preliminary exploration into the viability of creating materials that act as selective exchange media. We have historically been involved in the separation of ionic pollutants such as radionuclides or toxic heavy metal ions from water by designing extractants with high selectivities and large capacities. We have also recognized that there is a more urgent need to develop processes that allow the target pollutants to be recovered in a minimal volume of secondary waste and that allow the extractants to be reused or recycled. We have been studying redox active transition-metal-containing extractants that undergo reversible electron transfer activation and deactivation as the target ions are extracted and recovered or that undergo efficient, selective ion exchange.

(1) To determine if and when dynamical chaos theory can be used to investigate infiltration of fluid and contaminant transport in heterogeneous soils and fractured rocks. (2) To introduce a new approach to the multiscale characterization of flow and transport in fractured basalt vadose zones and to develop physically based conceptual models on a hierarchy of scales. The following activities are indicative of the success in meeting the project s objectives: A series of ponded infiltration tests, including (1) small-scale infiltration tests (ponded area 0.5 m2) conducted at the Hell s Half Acre site near Shelley, Idaho, and (2) intermediate-scale infiltration tests (ponded area 56 m2) conducted at the Box Canyon site near Arco, Idaho. Laboratory investigations and modeling of flow in a fractured basalt core. A series of small-scale dripping experiments in fracture models. Evaluation of chaotic behavior of flow in laboratory and field experiments using methods from nonlinear dynamics; Evaluation of the impact these dynamics may have on contaminant transport through heterogeneous fractured rocks and soils, and how it can be used to guide remediation efforts; Development of a conceptual model and mathematical and numerical algorithms for flow and transport that incorporate (1) the spatial variability of heterogeneous …

The overall goal of this Environmental Management Science Program project was to develop research tools to investigate the effect of transmutation, that is, the radioactive decay of a radioisotope to an isotope of another element, on the stability of a crystalline matrix. This process is an important issue in the assessment of the long-term stability, and hence performance, of a waste form. Most work on radiation effects in waste forms has focused on alpha radiation, which produces more displacements than beta radiation. However, beta radiation results in transmutation, which changes both the valence and the ionic radius of the element undergoing decay. These changes in coordination chemistry may destabilize the waste form and hence permit higher releases of the radionuclide contaminants to the accessible environment. Little is known about the mobility of Cs in pollucite. Only a few studies [1-3] have examined leaching following transmutation or irradiation of pollucite or closely related aluminosilicates. These studies seem to have contradictory results. The results may indicate that prior to radiation-induced amorphization, the accumulated defects may lead to higher leachability of Cs [3], whereas once amorphization occurs, the Cs becomes trapped in the collapsed structure [2]. A more thorough analysis of the effect …

In the United States alone there are 100 million gallons of high-level nuclear wastes (HLWs) in various chemical forms awaiting eventual disposal in geologic repositories. For safety in handling and transport from their present underground storage tanks to their final burial sites, much of the HLWs are being immobilized by vitrification. A further virtue of HLW vitrification is the fact that the glass may serve as an additional, non-geologic barrier to the dispersal of these radio-toxins into the environment. For this reason, one of the criteria for selecting HLW glass compositions has been chemical durability against attack by ground water. While the effects of radiation on chemical durability have therefore been studied extensively, little consideration has been given to the possibility that self-irradiation of HLW glasses may lead to modes of chemical decomposition which render them unstable even in the absence of exposure to ground water. The worst-case threat would occur if the HLW glasses were to respond to irradiation in ways analogous to rock salt (NaCl). It has long been known that alkali halides irradiated to

Metal ions are critical nutrients, yet overaccumulation of these same metals can also be toxic. To maintain appropriate intracellular levels, cells require specific metal uptake systems that are subject to precise homeostatic regulation. The long-range goal of our research is to define the molecular mechanism(s) and regulation of metal ion uptake in eukaryotic cells. Integrating genetic, molecular biological and biochemical approaches, we have examined these processes in the yeast Saccharomyces cerevisiae and the plant Arabidopsis thaliana. Both are proven model systems for studying fundamental cellular processes. Our work has focused on the ZIP family of metal transporters which we identified; this family has representatives in bacteria, fungi,plants and animals. IRT1, one of the founding members of the ZIP family, is an essential cation transporter that is expressed in the epidermal cells of iron deficient plant roots and is responsible for uptake of iron from the soil. We now know that t here are 15 ZIP genes in the Arabidopsis genome which can be divided into four different classes, based on their intron/exon arrangements and the similarities among their encoded gene products. The ZIP family members display different substrate specificities for metals and different tissue distributions in Arabidopsis.Moreover, the family members …

This project was conducted to determine if ionizing radiation could be used to catalytically destroy organics over semiconducting metal oxide particles. We focused primarily on the destruction of organic chelating agents, such as EDTA, which are known to hamper the separation of radionucleii (such as Sr or Am) from tank waste using current ion exchange methods. Our objective was to determine if ionizing radiation could be used to destroy the chelating capability of species such as EDTA, either by partially or completely decomposing the organic, in order to free radionucleii for efficient separation. Although a considerable amount of information is available in the open literature on the roles of visible/UV light in photocatalysis, little is known about the processes initiated by ionizing radiation. In this sense, the use of ionizing radiation is both novel, and may find an important niche in the pretreatment of mixed waste. An additional aim of the project was determine the mechanism(s) by which the radiocatalysis effect took place and compare it to what is know from visible and UV photocatalytic processes in the literature. The main outcome of this work is a more thorough evaluation of the use of ionizing radiation in the catalytic remediation …

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This report contains the experimental, theoretical and numerical studies performed under Department of Energy (DOE) Agreement Number DE-FG07-96ER14732 entitled ''Surface Nuclear Magnetic Resonance for Imaging Subsurface Water.'' DOE and Department of Defense (DOD) complexes and test ranges are situated in widely varying climatic conditions from the desert southwest to the humid east. The mission of the Office of Environmental Restoration and Waste Management (EM) is to clean up the inventory of inactive DOE sites and facilities, and the goal of the EM Office of Technology Development (OTD) is to deliver technologies to make environmental restoration more efficient and cost effective. In the western United States, where a number of DOE facilities are located, the water table can occur several hundred feet below the surface. The zone between surface and water table is called the vadose zone or unsaturated zone. A characteristic of that zone is that mobility of water and contaminants is greatly reduced compared to rate of movement in the saturated zone. A thick vadose zone lowers the risk and, at least, increases the time before contaminants enter drinking water supplies. The assessment of risk is often performed by modeling of ground water flow and contaminant migration by analytical …

The purpose of this program was to reduce the technical risk factors for demonstration of air cooled silicon nitride turbine vanes. The effort involved vane prototype fabrication efforts at two U.S. based gas turbine grade silicon nitride component manufacturers. The efficacy of the cooling system was analyzed via a thermal time/temperature flow test technique previously at UTRC. By having multiple vendors work on parts fabrication, the chance of program success increased for producing these challenging components. The majority of the effort under this contract focused on developing methods for, and producing, the complex thin walled silicon nitride vanes. Components developed under this program will undergo engine environment testing within N00014-96-2-0014.

Combustion experiments were carried out on four different residual fuel oils in a 732 kW boiler. Particulate matter (PM) emission samples were separated aerodynamically by a cyclone into fractions that were nominally less than and greater than 2.5 microns in diameter. However, examination of several of the samples by computer-controlled scanning electron microscopy (CCSEM) revealed that part of the <2.5 micron fraction (PM{sub 2.5}) in fact consists of carbonaceous cenospheres and vesicular particles that range up to 10 microns in diameter. X-ray absorption fine structure (XAFS) spectroscopy data were obtained at the S, V, Ni, Fe, Cu, Zn, and As Kedges, and at the Pb L-edge. Deconvolution of the x-ray absorption near edge structure (XANES) region of the S spectra established that the dominant molecular forms of S present were sulfate (26-84% of total S) and thiophene (13-39% of total S). Sulfate was greater in the PM{sub 2.5} samples than in the >2.5 micron samples (PM{sub 2.5+}). Inorganic sulfides and elemental sulfur were present in lower percentages. The Ni XANES spectra from all of the samples agree fairly well with that of NiSO4, while most of the V spectra closely resemble that of vanadyl sulfate (VO{center_dot}SO{sub 4}{center_dot}xH{sub 2}O). The other …