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Reducing Boron Toxicity by Microbial Sequestration

Description: While electricity is a clean source of energy, methods of electricity-production, such as the use of coal-fired power plants, often result in significant environmental damage. Coal-fired electrical power plants produce air pollution, while contaminating ground water and soils by build-up of boron, which enters surrounding areas through leachate. Increasingly high levels of boron in soils eventually overcome boron tolerance levels in plants and trees, resulting in toxicity. Formation of insoluble boron precipitates, mediated by mineral-precipitating bacteria, may sequester boron into more stable forms that are less available and toxic to vegetation. Results have provided evidence of microbially-facilitated sequestration of boron into insoluble mineral precipitates. Analyses of water samples taken from ponds with high boron concentrations showed that algae present contained 3-5 times more boron than contained in the water in the samples. Boron sequestration may also be facilitated by the incorporation of boron within algal cells. Experiments examining boron sequestration by algae are in progress. In bacterial experiments with added ferric citrate, the reduction of iron by the bacteria resulted in an ironcarbonate precipitate containing boron. An apparent color change showing the reduction of amorphous iron, as well as the precipitation of boron with iron, was more favorable at higher pH. Analysis of precipitates by X-ray diffraction, scanning electron microscopy, and inductively coupled plasma mass spectroscopy revealed mineralogical composition and biologicallymediated accumulation of boron precipitates in test-tube experiments.
Date: January 1, 2002
Creator: Hazen, T. & Phelps, T.J.
Partner: UNT Libraries Government Documents Department

Enhancement of Fe (III), Co (III), and Cr (VI) reduction at elevated temperatures and by a thermophilic bacterium

Description: An unusual thermophilic bacterium has been isolated from deep subsurface sediments and tested for its ability to enhance Fe(III), Co(III), and Cr(VI) reduction. Without the bacterium, abiotic metal reduction was insignificant at temperatures below 45{degrees}C but became a major process at 75{degrees}C. Addition of the bacterium enhanced the reduction of these metals up to fourfold. This study demonstrates abiotic and biotic metal reduction under organic-rich thermic conditions and suggest that thermally and/or biologically enhanced metal reduction may provide an alternative for remediating metal contamination.
Date: July 1, 1995
Creator: Zhang, C.; Liu, Shi; Logan, J.; Mazumder, R. & Phelps, T.J.
Partner: UNT Libraries Government Documents Department

Microbial activities in deep subsurface environments

Description: Activities of microorganisms residing in terrestrial deep subsurface sediments were examined in forty-six sediment samples from three aseptically sampled boreholes. Radiolabeled time course experiments assessing in situ microbial activities were initiated within 30 minutes of core recovery. [{sup 14}C-1-] Acetate incorporation into lipids. [methyl-{sup 3}H-]thymidine incorporation into DNA, [{sup 14}C-2-]acetate and [{sup 14}C-U-]glucose mineralization in addition to microbial enrichment and enumeration studies were examined in surface and subsurface sediments. Surface soils contained the greatest biomass and activities followed by the shallow aquifer zones. Water saturated subsurface sediments exhibited three to four orders of magnitude greater activity and culturable microorganisms than the dense clay zones. Regardless of depth, sediments which contained more than 20% clays exhibited the lowest activities and culturable microorganisms.
Date: Spring 1988
Creator: Phelps, T. J.; Raione, E. G.; White, D. C. & Fliermans, C. B.
Partner: UNT Libraries Government Documents Department

Mineralization of trichloroethylene by heterotrophic enrichment cultures

Description: Microbial consortia capable of aerobically degrading greater than 99% of 50 mg/l exogenous trichloroethylene (TCE) have been enriched from TCE contaminated subsurface sediments. Concentrations of TCE greater than 300 mg/l were not degraded nor was TCE used as a sole energy source. Successful electron donors for growth included tryptone-yeast extract, methanol, methane or propane. The optimum temperature for growth was 22--37 C and the ph optimum was 7.0--8.1. Utilization of TCE occurred only after apparent microbial growth had ceased. The major end products recovered were hydrochloric acid and carbon dioxide. Minor products included dichloroethylene, vinylidine chloride and possibly chloroform.
Date: Spring 1988
Creator: Phelps, T. J.; Ringelberg, D.; Mikell, A. T.; White, D. C. & Fliermans, C. B.
Partner: UNT Libraries Government Documents Department

Subsurface microbial communities and degradative capacities during trichloroethylene bioremediation

Description: Subsurface amendments of air, methane, and nutrients were investigated for the in situ stimulation of trichloroethylene- degrading microorganisms at the US DOE Savannah River Integrated Demonstration. Amendments were injected into a lower horizontal well coupled with vacuum extraction from the vadose zone horizontal well. The amendments were sequenced to give increasingly more aggressive treatments. Microbial populations and degradative capacities were monitored in groundwaters samples bimonthly.
Date: December 31, 1995
Creator: Pfiffner, S.M.; Ringelberg, D.B.; Hedrick, D.B.; Phelps, T.J. & Palumbo, A.V.
Partner: UNT Libraries Government Documents Department

Apparatus and method for phosphate-accelerated bioremediation

Description: An apparatus and method for supplying a vapor-phase nutrient to contaminated soil for in situ bioremediation. The apparatus includes a housing adapted for containing a quantity of the liquid nutrient, a conduit in fluid communication with the interior of the housing, means for causing a gas to flow through the conduit, and means for contacting the gas with the liquid so that a portion thereof evaporates and mixes with the gas. The mixture of gas and nutrient vapor is delivered to the contaminated site via a system of injection and extraction wells configured to the site. The mixture has a partial pressure of vaporized nutrient that is no greater than the vapor pressure of the liquid. If desired, the nutrient and/or the gas may be heated to increase the vapor pressure and the nutrient concentration of the mixture. Preferably, the nutrient is a volatile, substantially nontoxic and nonflammable organic phosphate that is a liquid at environmental temperatures, such as triethyl phosphate or tributyl phosphate.
Date: January 1994
Creator: Looney, B. B.; Phelps, T. J.; Hazen, T. C.; Pfiffner, S. M.; Lombard, K. H. & Borthen, J. W.
Partner: UNT Libraries Government Documents Department

Influence of Other Contaminants on Natural Attenuation of Chlorinated Solvents

Description: Studies at numerous sites have shown high variability in the degradation rates of chlorinated solvents as measured by microcosm studies with <sup>14</sup>C labeled contaminants. The ability of nutrient and carbon additions to stimulate degradation can vary widely. Although some of these variations can be related to the structure of the extant microbial community, the presence of other less refractory contaminants may be critical fctors impacting the rate of chlorocarbon mineralization. Relaatively highe rates of TCE degradation have been observed in the DOE K-25 burial grounds with diverse organic loadings as well as in areas that show evidence for hydrocarbon contamination. Similarly, at other sites where there was TCE in the absence of hydrocarbons or other contaminants, the measured degradation rates have often been found to be very low. At various other sites, the intrasite variability in degradation rates appeared to be related to the presence of hydrocarbon contamination. The highest rates were observed at sites with evidence of hydrocarbons. These observations indicated that the viability of natural attenuation as a remediation option for chlorinated solvents might depend in part on the presence co-contaminants such as hydrocarbons or natural matter.
Date: April 19, 1999
Creator: Kinsall, B.L.; Palumbo, A.V.; Pfiffner, S.M.; Phelps, T.J. & Salpas, P.
Partner: UNT Libraries Government Documents Department

Deployment Plan for Bioremediation and Natural Attenuation for In Situ Restoration of Chloroethene-Contaminated Groundwater

Description: This deployment plan describes a project funded by the Accelerated Site Technology Deployment Program of the U.S. Department of Energy (DOE). The objective is to facilitate deployment of enhanced in situ bioremediation (ISB) an monitored natural attenuation (MNA) or chloroethene-contaminated groundwater to DOE sites. Enhanced ISB accelerates dechlorination of chloroethenes under anaerobic conditions by providing nutrients to the microbial community. Natural attenuation does not require nutrient addition. Enhanced ISB in the upgradient portion of a contaminant plume couples with MNA in the downgradient portion is being implemented at Test Area North (TAN) at the Idaho National Engineering and Environmental Laboratory. Selected DOE sites will be screened to assess their suitability for enhanced ISB/MNA. Tasks include: (1) characterization of the TAN microbial community and correlation of community characteristics with chloroethene degradation ability, (2) installation of wells to facilitate evaluation of MNA at TAN, (3) monitoring to better delineate MNA at TAN, and (4) screening of selected other DOE sites for suitability of ISB/MNA, and limited supplemental characterization. Data evaluation will provide a sound technical basis for decision makers to consider use of enhanced ISB and MNA, alone or together, as remedial technologies for these sites.
Date: March 1, 1999
Creator: Peterson, L.N.; Starr, R.C.; Sorenson, K.S.; Smith, R.W. & Phelps, T.J.
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

Bioremediation demonstration on Kwajalein Island: Site characterization and on-site biotreatability studies

Description: An environmental study was conducted during February 1991 on Kwajalein Island, a US Army Kwajalein Atoll (USAKA) Base in the Republic of the Marshall Islands (RMI). This study was undertaken for the US Department of Energy (DOE) Hazardous Waste Remedial Actions Program (HAZWRAP) acting in behalf of USAKA. The purpose of the study was to determine if selected locations for new construction on Kwajalein Island were contaminated by petroleum hydrocarbons as suspected and, if so, whether bioremediation appeared to be a feasible technology for environmental restoration. Two different sites were evaluated: (1) the site planned freshwater production facility and (2) a site adjacent to an aboveground diesel fuel storage tank. Within the proposed construction zone for the freshwater production facility (a.k.a desalination plant), total petroleum hydrocarbons (TPH) where either absent or at low levels. Characterization data for another potential construction site adjacent to an aboveground diesel fuel storage tank southeast of the old diesel power plant revealed high concentrations of diesel fuel in the soil and groundwater beneath the site. Results of this investigation indicate that there are petroleum-contaminated soils on Kwajalein Island and bioremediation appears to be a viable environmental restoration technique. Further experimentation and field demonstration are required to determine the design and operating conditions that provide for optimum biodegradation and restoration of the petroleum-contaminated soils. 17 refs., 7 figs., 26 figs.
Date: September 1, 1991
Creator: Siegrist, R.L.; Korte, N.E.; Pickering, D.A. (Oak Ridge National Lab., TN (United States)) & Phelps, T.J. (Tennessee Univ., Knoxville, TN (United States))
Partner: UNT Libraries Government Documents Department

A co-metabolic approach to groundwater remediation

Description: In support of the US Department of Energy's (DOE) Integrated Demonstration (Cleanup of Organics in Soils and Groundwater at Non-arid Sites) at the Savannah River Site (SRS), Oak Ridge National Laboratory (ORNL) and the University of Tennessee (UT) are involved in demonstrations of the use of methanotrophs in bioreactors for remediation of contaminated groundwater. In preparation for a field demonstration at ORNL's K-25 Site in Oak Ridge, Tennessee, ORNL is conducting batch experiments, is operating a number of bench-scale bioreactors, has designed pretreatment systems, and has modified a field-scale bioreactor provided by the Air Force Engineering and Services Center for use at the site. UT is operating bench-scale bioreactors with the goal of determining the stability of a trichloroethylene-degrading methanotrophic consortia during shifts in operating conditions (e.g. pH, nutrient inputs, and contaminant mixtures). These activities are all aimed at providing the knowledge base necessary for successful treatment of contaminated groundwater at the SRS and K-25 sites as well as other DOE sites. 18 refs., 1 fig. , 1 tab.
Date: January 1, 1991
Creator: Palumbo, A.V.; Boerman, P.A.; Strandberg, G.W.; Donaldson, T.L.; Jennings, H.L.; Lucero, A.J. et al.
Partner: UNT Libraries Government Documents Department