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Impact of thermal loading and other water quality parameters on the epizootiology of red-sore disease in centrarchids. Progress report, December 1, 1977--November 30, 1978

Description: The implications from these studies are varied, sometimes clear and sometimes less so, for many of the results have raised new and even more critical questions. Thus, our data clearly show that Aeromonas hydrophila is the etiological agent for red-sore disease. Furthermore, they suggest that the effects of temperature are twofold, first in increasing the density of the pathogen in the water column and then in affecting the physiology of the host organism to such an extent as to increase the probability of acquiring the pathogen. On the other hand, organic loading, suggested by other investigators as being important in red-sore disease, was not identified as being significant in the present study. However, if organic loading, or any of its consequences, can be shown to induce stress, then it may be as important in other systems as temperature is in Par Pond. Thus it is quite conceivable that it (organic loading), or some other water quality parameter, may create conditions conducive to increasing densities of A. hydrophila while simultaneously producing water quality characteristics which would lead to stress in fish, and then to increasing the probability of fish acquiring red-sore disease. An enigmatic observation (see Hazen, 1978, for details) is that A. hydrophila has been recovered from a variety of habitats throughout the U.S., yet red-sore disease is known to occur only in the southeast. This peculiar distribution pattern raises several important questions regarding the epizootiology of red-sore, not the least of which is the possibility of there existing differentially virulent strains of A. hydrophila and/or more or less susceptible populations of potential hosts in various parts of the country. Other significant questions are related to the variability in amplitude of red-sore disease from one year to the next among bass in Par Pond, the mode of entry of the ...
Date: July 1, 1978
Creator: Esch, G.W. & Hazen, T.C.
Partner: UNT Libraries Government Documents Department

Immersible solar heater for fluids

Description: An immersible solar heater is described comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater.
Date: January 1, 1994
Creator: Hazen, T.C. & Fliermans, C.B.
Partner: UNT Libraries Government Documents Department

Bioremediation of contaminated groundwater

Description: Disclosed is an apparatus and method for in situ remediation of contaminated subsurface soil or groundwater contaminated by chlorinated hydrocarbons. A nutrient fluid (NF) is selected to simulated the growth and reproduction of indigenous subsurface microorganisms capable of degrading the contaminants; an oxygenated fluid (OF) is selected to create an aerobic environment with anaerobic pockets. NF is injected periodically while OF is injected continuously and both are extracted so that both are drawn across the plume. NF stimulates microbial colony growth; withholding it periodically forces the larger, healthy colony of microbes to degrade the contaminants. Treatment is continued until the subsurface concentration of contaminants is acceptable. NF can be methane and OF be air, for stimulating production of methanotrophs to break down chlorohydrocarbons, especially TCE and tetrachloroethylene.
Date: January 1, 1994
Creator: Hazen, T.C. & Fliermans, C.B.
Partner: UNT Libraries Government Documents Department

The effect of vacuum pump oil on the chemotactic behavior of soil bacteria

Description: The use of biodegradation in the cleanup and transformation of waste materials is an economical and environmentally safe practice. Using chemotaxis, or the movement of bacteria toward or away from compounds, in biodegradation is an area that is being studied at the Savannah River Laboratory. This study investigates the inhibition of vacuum pump oil on the chemotaxis of soil bacteria. It was found that vacuum pump oil does have an inhibitory effect on the movement of bacteria. This inhibition will have to be considered when studying the possibility of using chemotaxis to degrade vacuum pump oil, or any other petroleum products. 5 refs., 5 figs.
Date: January 1, 1990
Creator: Dunifon, R.E. & Hazen, T.C.
Partner: UNT Libraries Government Documents Department

New insights into microbial responses to oil spills from the Deepwater Horizon incident

Description: On April 20, 2010, a catastrophic eruption of methane caused the Deepwater Horizon exploratory drill rig drilling the Macondo Well in Mississippi Canyon Block 252 (MC252) to explode. The Deepwater Horizon oil spill was unprecendeted for several reasons: the volume of oil released; the spill duration; the well depth; the distance from the shore-line (77 km or about 50 miles); the type of oil (light crude); and the injection of dispersant directly at the wellhead. This study clearly demonstrated that there was a profound and significant response by certain members of the in situ microbial community in the deep-sea in the Gulf of Mexico. In particular putative hydrocarbon degrading Bacteria appeared to bloom in response to the Deepwater Horizon oil spill, even though the temperature at these depths is never >5 C. As the plume aged the shifts in the microbial community on a temporal scale suggested that different, yet metabolically important members of the community were able to respond to a myriad of plume constituents, e.g. shifting from propane/ethane to alkanes and finally to methane. Thus, the biodegradation of hydrocarbons in the plume by Bacteria was a highly significant process in the natural attenuation of many compounds released during the Deepwater Horizon oil spill.
Date: June 15, 2011
Creator: Mason, O.U. & Hazen, T.C.
Partner: UNT Libraries Government Documents Department

Systems biology approach to bioremediation

Description: Bioremediation has historically been approached as a �black box� in terms of our fundamental understanding. Thus it succeeds and fails, seldom without a complete understanding of why. Systems biology is an integrated research approach to study complex biological systems, by investigating interactions and networks at the molecular, cellular, community, and ecosystem level. The knowledge of these interactions within individual components is fundamental to understanding the dynamics of the ecosystem under investigation. Understanding and modeling functional microbial community structure and stress responses in environments at all levels have tremendous implications for our fundamental understanding of hydrobiogeochemical processes and the potential for making bioremediation breakthroughs and illuminating the �black box�.
Date: January 1, 2012
Creator: Chakraborty, R.; Wu, C. H. & Hazen, T. C.
Partner: UNT Libraries Government Documents Department

Complexity of Groundwater Contaminants at DOE Sites

Description: The U.S. Department of Energy (DOE) is responsible for the remediation and long-term stewardship of one of the world's largest groundwater contamination portfolios, with a significant number of plumes containing various contaminants, and considerable total mass and activity. As of 1999, the DOE's Office of Environmental Management was responsible for remediation, waste management, or nuclear materials and facility stabilization at 144 sites in 31 states and one U.S. territory, out of which 109 sites were expected to require long-term stewardship. Currently, 19 DOE sites are on the National Priority List. The total number of contaminated plumes on DOE lands is estimated to be 10,000. However, a significant number of DOE sites have not yet been fully characterized. The most prevalent contaminated media are groundwater and soil, although contaminated sediment, sludge, and surface water also are present. Groundwater, soil, and sediment contamination are present at 72% of all DOE sites. A proper characterization of the contaminant inventory at DOE sites is critical for accomplishing one of the primary DOE missions -- planning basic research to understand the complex physical, chemical, and biological properties of contaminated sites. Note that the definitions of the terms 'site' and 'facility' may differ from one publication to another. In this report, the terms 'site,' 'facility' or 'installation' are used to identify a contiguous land area within the borders of a property, which may contain more than one plume. The term 'plume' is used here to indicate an individual area of contamination, which can be small or large. Even though several publications and databases contain information on groundwater contamination and remediation technologies, no statistical analyses of the contaminant inventory at DOE sites has been prepared since the 1992 report by Riley and Zachara. The DOE Groundwater Data Base (GWD) presents data as of 2003 for 221 groundwater ...
Date: December 3, 2010
Creator: Hazen, T.C.; Faybishenko, B. & Jordan, P.
Partner: UNT Libraries Government Documents Department

Distribution of Aeromonas hydrophila in a South Carolina cooling reservoir. [Aeromonas hydrophila]

Description: Par Pond is a thermally enriched monomictic southeastern lake which receives heated effluent from a production nuclear reactor. Fish populations in the lake have lesions of epizooty from which Aeromonas spp. are readily isolated. Distribution and population densities of Aeromonas in the water column were measured along an oxygen and temperature gradient. Greater population densities of Aeromonas occurred below the oxygen chemocline when the lake was stratified. Survival of A. hydrophila under in situ conditions in both epilimnetic and hypolimnetic waters was determined using polycarbonate membrane diffusion chambers, during two separate reactor operating conditions. Survival levels of pure cultures of A. hydrophila corresponded to the distribution patterns of the naturally occurring Aeromonas-like populations. The greater survival of A. hydrophila below the chemocline when the reactor was in full operation suggests that the fish populations may be exposed to Aeromonas for a longer period of time than when the reactor is not operating.
Date: January 1, 1977
Creator: Fliermans, C.B.; Gorden, R.W.; Hazen, T.C. & Esch, G.W.
Partner: UNT Libraries Government Documents Department

Autecology of Vibrio vulnificus and Vibrio parahaemolyticus in tropical waters

Description: Water and shellfish samples collected from estuaries, mangroves, and beaches along the coast of Puerto Rico were examined for Vibrio vulnificus and Vibrio parahaemolyticus. An array of water quality parameters were also measured simultaneous with bacteria sampling. Both species of vibrio were associated with estuary and mangrove locations, and neither was isolated from sandy beaches. Densities of V. vulnificus were negatively correlated with salinity, 10--15 ppt being optimal. V. parahaemolyticus was isolated from sites with salinities between 20 and 35 ppt, the highest densities occurring at 20 ppt. Densities of Vibrio spp. and V. parahaemolyticus for a tropical estuary surpassed those reported for temperate estuaries by several orders of magnitude. Both densities of total Vibrio spp. and V. parahaemolyticus in the water were directly related to densities of fecal coliforms, unlike V. vulnificus. The incidence of ONPG(+) strains among sucrose({minus}) Vibrio spp. served as an indicator of the frequency of V. vulnificus in this group. More than 63% of the V. vulnificus isolated were pathogenic. V. vulnificus and V. parahaemolyticus occupy clearly separate niches within the tropical estuarine-marine ecosystem.
Date: Spring 1988
Creator: Rivera, S.; Lugo, T. & Hazen, T. C.
Partner: UNT Libraries Government Documents Department

Preliminary technology report for Southern Sector bioremediation

Description: This project was designed to demonstrate the potential of intrinsic bioremediation and phytoremediation in the Southern Sector of the A/M-Area at the Savannah River Site. A subsurface plume of trichloroethylene (TCE) and perchloroethylene (PCE) is present in the Lost Lake aquifer upgradient of the study site and is predicted to impact the area at some point in the future. The surface area along the Lost lake aquifer seep line where the plume is estimated to emerge was identified. Ten sites along the seep line were selected for biological, chemical, and contaminant treatability analyses. A survey was undertaken in this area to to quantify the microbial and plant population known to be capable of remediating TCE and PCE. The current groundwater quality upgradient and downgradient of the zone of influence was determined. No TCE or PCE was found in the soils or surface water from the area tested at this time. A TCE biodegradation treatability test was done on soil from the 10 selected locations. From an initial exposure of 25 ppm of TCE, eight of the samples biodegraded up to 99.9 percent of all the compound within 6 weeks. This biodegradation of TCE appears to be combination of aerobic and anaerobic microbial activity as intermediates that were detected in the treatability test include vinyl chloride (VC) and the dichloroethenes (DCE) 1,2-cis-dichloroethylene and 1,1-dichloroethylene. The TCE biological treatability studies were combines with microbiological and chemical analyses. The soils were found through immunological analysis with direct fluorescent antibodies (DFA) and microbiological analysis with direct fluorescent antibodies (DFA) and microbiological analysis to have a microbial population of methanotrophic bacteria that utilize the enzyme methane monooxygenase (MMO) and cometabolize TCE.
Date: June 1, 1997
Creator: Brigmon, R.L.; White, R.; Hazen, T.C.; Jones, D. & Berry, C.
Partner: UNT Libraries Government Documents Department

Immobilization of degradative bacteria in polyurethane-based foams: embedding efficiency and effect on bacterial activity

Description: The immobilization of TCE-degrading bacterium Burkholderia cepacia was evaluated using hydrophilic polyurethane foam. The influence of several foam formulation parameters upon cell retention was examined. Surfactant type was a major determinant of retention, with a lecithin- based compound retaining more cells than pluronic or silicone based surfactants. Excessive amounts of surfactant led to increased washout of bacteria. Increasing the biomass concentration from 4.8% to 10.5% caused fewer cells to be washed out. Embedding at reduced temperature did not significantly affect retention, while the use of a silane binding agent gave inconsistent results. The optimal formulation retained all but 0.2% of total embedded cells during passage of 2 liters of water through columns containing 2 g of foam. All foam formulations tested reduced the culturability of embedded cells by several orders of magnitude. However, O{sub 2} and CO{sub 2} evolution rates of embedded cells were never less than 50% of unembedded cells. Nutrient amendments stimulated an increase in cell volume and ribosomal activity as indicated by hybridization studies using fluorescently labeled ribosomal probes. these results indicated that, although immobilized cells were nonculturable, they were metabolically active and thus could be used for biodegradation of toxic compounds.
Date: September 3, 1996
Creator: Wilde, E.W.; Radway, J.C.; Hazen, T.C. & Hermann, P.
Partner: UNT Libraries Government Documents Department

D-area oil seepage basin bioventing optimization test plan

Description: The D Area Oil Seepage Basin (DOSB) was used from 1952 to 1975 for disposal of petroleum-based products (waste oils), general office and cafeteria waste, and apparently some solvents [trichloroethylene (TCE)/tetrachloroethylene (PCE)]. Numerous analytical results have indicated the presence of TCE and its degradation product vinyl chloride in groundwater in and around the unit, and of petroleum hydrocarbons in soils within the unit. The DOSB is slated for additional assessment and perhaps for environmental remediation. In situ bioremediation represents a technology of demonstrated effectiveness in the reclamation of sites contaminated with petroleum hydrocarbons and chlorinated solvents, and has been retained as an alternative for the cleanup of the DOSB. The Savannah River Site is therefore proposing to conduct a field treatability study designed to demonstrate and optimize the effectiveness of in situ microbiological biodegradative processes at the DOSB. The introduction of air and gaseous nutrients via two horizontal injection wells (bioventing) is expected to enhance biodegradation rates of petroleum components and stimulate microbial degradation of chlorinated solvents. The data gathered in this test will allow a determination of the biodegradation rates of contaminants of concern in the soil and groundwater, allow an evaluation of the feasibility of in situ bioremediation of soil and groundwater at the DOSB, and provide data necessary for the functional design criteria for the final remediation system.
Date: December 31, 1998
Creator: Berry, C.J.; Radway, J.C.; Alman, D. & Hazen, T.C.
Partner: UNT Libraries Government Documents Department

Final technology report for D-Area oil seepage basin bioventing optimization test, environmental restoration support

Description: One method proposed for the cleanup of the D-Area Oil Seepage Basin was in situ bioremediation (bioventing), involving the introduction of air and gaseous nutrients to stimulate contaminant degradation by naturally occurring microorganisms. To test the feasibility of this approach, a bioventing system was installed at the site for use in optimization testing by the Environmental Biotechnology Section of the Savannah River Technology Center. During the interim action, two horizontal wells for a bioventing remediation system were installed eight feet below average basin grade. Nine piezometers were also installed. In September of 1996, a generator, regenerative blower, gas cylinder station, and associated piping and nutrient injection equipment were installed at the site and testing was begun. After baseline characterization of microbial activity and contaminant degradation at the site was completed, four injection campaigns were carried out. These consisted of (1) air alone, (2) air plus triethylphosphate (TEP), (3) air plus nitrous oxide, and (4) air plus methane. This report describes results of these tests, together with conclusions and recommendations for further remediation of the site. Natural biodegradation rates are high. Oxygen, carbon dioxide, and methane levels in soil gas indicate substantial levels of baseline microbial activity. Oxygen is used by indigenous microbes for biodegradation of organics via respiration and hence is depleted in the soil gas and water from areas with high contamination. Carbon dioxide is elevated in contaminated areas. High concentrations of methane, which is produced by microbes via fermentation once the oxygen has been depleted, are found at the most contaminated areas of this site. Groundwater measurements also indicated that substantial levels of natural contaminant biodegradation occurred prior to air injection.
Date: January 24, 1997
Creator: Radway, J.C.; Lombard, K.H. & Hazen, T.C.
Partner: UNT Libraries Government Documents Department

Microbial response to triepthylphosphate

Description: The effect of triethylphosphate (TEP) on the activity of a landfill aquifer microbial community was evaluated using standard techniques and in situ hybridizations with phylogenetic probes. Benzene was used as an external carbon source to monitor degradation of an aromatic compound in TEP amended microcosms. Microscopical and viable counts were higher in TEP containing microcosms when compared to unamended controls. A significant increase in metabolic activity was also observed for TEP amended samples as determined by the number of cells hybridizing to an eubacterial probe. In addition, the number of beta and gamma Proteobacteria increased from undetectable levels prior to the study to 15-29% of the total bacteria in microcosms containing TEP and benzene. In these microcosms, nearly 40% of the benzene was degraded during the incubation period compared to less than 5% in unamended microcosms. While TEP has previously been used as an alternate phosphate source in the bioremediation of chlorinated aliphatics, this study shows that it can also stimulate the microbial degradation of aromatics in phosphate limited aquifers.
Date: May 1, 1997
Creator: Hazen, T.C.; Santo Domingo, J.W. & Berry, C.J.
Partner: UNT Libraries Government Documents Department

Survival and distribution of Vibrio cholerae in a tropical rain forest stream

Description: For 12 months Vibrio cholerae and fecal coliforms were monitored along with 9 other water quality parameters at 12 sites in a rain forest watershed in Puerto Rico. Densities of V. cholerae and fecal coliforms were not significantly correlated even though the highest densities of both bacteria were found at a sewage outfall. High densities of V. cholerae were also found at pristine sites high in the watershed. V. cholerae and Escherichia coli were inoculated into membrane diffusion chambers, placed at two sites and monitored for 5 days on two different occasions. Two different direct count methods indicated that the density of E. coli and V. cholerae did not change significantly during the course of either study. Physiological activity, as measured by INT-reduction and relative nucleic acid composition declined for E. coli during the first 12 h then increased and remained variable during the remainder of the study. V. cholerae activity, as measured by relative nucleic acid concentrations, remained high and unchanged for the entire study. INT-reduction in V. cholerae declined initially but regained nearly all of it`s original activity within 48 h. This study suggests that V. cholerae is an indigenous organism in tropical freshwaters and that assays other than fecal coliforms or E. coli must be used for assessing public health risk in tropical waters.
Date: Spring 1988
Creator: Perez-Rosas, N. & Hazen, T. C.
Partner: UNT Libraries Government Documents Department

Survival and activity of Streptococcus faecalis and Escherichia coli in petroleum-contaminated tropical marine waters

Description: The in situ survival and activity of Streptococcus faecalis and Escherichia coli were studied using membrane diffusion chambers in tropical marine waters receiving oil refinery effluents. Protein synthesis, DNA synthesis, respiration or fermentation, INT reduced per cell, and ATP per cell were used to measure physiological activity. Cell densities decreased significantly over time at both sites for both S. faecalis and E. coli; however, no significant differences in survival pattern were observed between S. faecalis and E.coli. Differences in protein synthesis between the two were only observed at a study site which was not heavily oiled. Although fecal streptococci have been suggested as a better indicator of fecal contamination than fecal coliforms in marine waters, in this study both E. coli and S. faecalis survived and remained physiologically active for extended periods of time. These results suggest that the fecal streptococci group is not a better indicator of fecal contamination in tropical marine waters than the fecal coliform group, especially when that environment is high in long-chained hydrocarbons.
Date: Spring 1987
Creator: Santo Domingo, J. W.; Fuentes, F. A. & Hazen, T. C.
Partner: UNT Libraries Government Documents Department

Test plan: the Czechowice Oil Refinery bioremediation demonstration of a process waste lagoon

Description: The remediation strategies that will be applied at the Czechowice Oil Refinery waste lagoon in Czechowice, Poland are designed, managed, and implemented under the direction of the Westinghouse Savannah River Company (WSRC) for the United States Department of Energy (DOE). WSRC will be assisted in the demonstration by The Institute for Ecology of Industrial Areas (IETU). This collaboration between IETU and DOE will provide the basis for international technology transfer of new and innovative remediation technologies that can be applied in Poland and the Eastern European Region as well.
Date: March 31, 1997
Creator: Altman, D.J.; Lombard, K.H. & Hazen, T.C.
Partner: UNT Libraries Government Documents Department

Characterization and reclamation assessment for the central shops diesel storage facility at Savannah River Site

Description: The contamination of subsurface terrestrial environments by organic contaminants is a global phenomenon. The remediation of such environments requires innovative assessment techniques and strategies for successful cleanups. Using innovative approaches, the central Shops Diesel Storage Facility at the Savannah River Site (SRS) was characterized to determine the extent of subsurface diesel fuel contamination. Effective bioremediation techniques for cleaning up of the contaminant plume were established.
Date: December 31, 1994
Creator: Fliermans, C.B.; Hazen, T.C. & Bledsoe, H.W.
Partner: UNT Libraries Government Documents Department

Biofouling of microfilters at the Savannah River Site F/H-Area Effluent Treatment Facility

Description: The F/H-Effluent Treatment Facility uses state-of-the-art water treatment processes to remove contaminants from low-level radioactive wastewater at the Savannah River Site. The plant replaces seepage basins that were closed to comply with the 1984 amendments to the Resource Conservation and Recovery Act (RCRA). The facility removes both radioactive and nonradioactive contaminants from the effluents orginating from onsite waste management facilities. The unit processes involve filtration, ion exchange, activated carbon absorption, and reverse osmosis. The filtration step is prone to considerable fouling, reducing the overall throughput of the facility. The filters utilized in the process are Norton Ceraflo{trademark} ceramic microfilters. It was discovered that bacteria were primarily responsible for the severe filter fouling. Inorganic fouling was also observed, but was not normally as severe as the bacterial fouling. The bacteria densities necessary to induce severe fouling were not significantly higher than those often found in surface water streams. Diversion of waste streams containing the highest quantity of bacteria, and various methods of source reduction were implemented, which dramatically improved the filter performance. Addition of aluminum nitrate at low pH further improved the filter performance.
Date: January 1, 1991
Creator: McCabe, D.J.; Wiggins, A.W.; Poirier, M.R. & Hazen, T.C.
Partner: UNT Libraries Government Documents Department

Full scale field test of the in situ air stripping process at the Savannah River integrated demonstration test site

Description: Under sponsorship from the US Department of Energy, technical personnel from the Savannah River Laboratory (SRL) and other DOE laboratories, universities and private industry have completed a full scale demonstration of environmental remediation using horizontal wells. This demonstration was performed as Phase I of an Integrated Demonstration Project designed to evaluate innovative remediation technologies for environmental restoration of sites contaminated with organic contaminants. The demonstration utilized two directionally drilled horizontal wells to deliver gases and extract contaminants from the subsurface. The resulting in situ air stripping process was designed to remediate soils and sediments above and below the water table as well as groundwater contaminated with volatile organic contaminants. The 139 day long test successfully removed volatile chlorinated solvents from the subsurface using the two horizontal wells. One well, approximately 300 ft (90m) long and 165 ft (50m) deep drilled below a contaminant plume in the groundwater, was used to inject air and strip the contaminants from the groundwater. A second horizontal well, approximately 175 ft (53m) long and 75 ft (23m) deep in the vadose zone, was used to extract residual contamination in the vadose zone along with the material purged from the groundwater. Pretest and posttest characterization data and monitoring data during the demonstration were collected to aid in interpretation of the test and to provide the information needed for future environmental restoration that employ directionally drilled wells as extraction or delivery systems. Contaminant concentration data and microbiological monitoring data are summarized in this report; the characterization data and geophysical monitoring data are documented in a series of related project reports.
Date: June 29, 1991
Creator: Looney, B.B.; Hazen, T.C.; Kaback, D.S. & Eddy, C.A.
Partner: UNT Libraries Government Documents Department

Fouling of ceramic filters and thin-film composite reverse osmosis membranes by inorganic and bacteriological constituents

Description: Two significant problems have been identified during the first three years of operating the Savannah River Site Effluent Treatment Facility. These problems encompass two of the facility's major processing areas: the microfiltration and reverse osmosis steps. The microfilters (crossflow ceramic filters {minus}0.2{mu} nominal pore size) have been prone to pluggage problems. The presence of bacteria and bacteria byproducts in the microfilter feed, along with small quantities of colloidal iron, silica, and aluminum, results in a filter foulant that rapidly deteriorates filter performance and is difficult to remove by chemical cleaning. Processing rates through the filters have dropped from the design flow rate of 300 gpm after cleaning to 60 gpm within minutes. The combination of bacteria (from internal sources) and low concentrations of inorganic species resulted in substantial reductions in the reverse osmosis system performance. The salt rejection has been found to decrease from 99+% to 97%, along with a 50% loss in throughput, within a few hours of cleaning. Experimental work has led to implementation of several changes to plant operation and to planned upgrades of existing equipment. It has been shown that biological control in the influent is necessary to achieve design flowrates. Experiments have also shown that the filter performance can be optimized by the use of efficient filter backpulsing and the addition of aluminum nitrate (15 to 30 mg/L Al{sup 3+}) to the filter feed. The aluminum nitrate assists by controlling adsorption of colloidal inorganic precipitates and biological contaminants. In addition, improved cleaning procedures have been identified for the reverse osmosis units. This paper provides a summary of the plant problems and the experimental work that has been completed to understand and correct these problems.
Date: January 1, 1991
Creator: Siler, J.L.; Poirier, M.R.; McCabe, D.J. & Hazen, T.C.
Partner: UNT Libraries Government Documents Department

Ground water and soil remediation: In situ air stripping using horizontal wells

Description: An innovative environmental restoration technology, in situ air stripping, has been demonstrated at the US Department of Energy (DOE) Savannah River Site (SRS) in South Carolina. This process, using horizontal wells, is designed to concurrently remediate unsaturated-zone soils and ground water containing Volatile Organic Compounds (VOC). In situ technologies have the potential to substantially reduce costs and time required for remediation as well as improve effectiveness of remediation. Horizontal wells were selected to deliver and extract fluids from the subsurface because their geometry can maximize the efficiency of a remediation system and they have great potential for remediating contaminant sources under existing facilities. The first demonstration of this new technology was conducted for a period of twenty weeks. A vacuum was first drawn on the vadose zone well until a steady-state removal of VOCs was obtained. Air was then injected at three different rates and at two different temperatures. An extensive characterization program was conducted at the site and an extensive monitoring network was installed prior to initiation of the test. Significant quantities of VOCs have been removed from the subsurface (equivalent to an eleven-well, 500-gpm, pump-and-treat system at the same site). Concentrations of VOCs in the ground water have been significantly reduced in a number of the monitoring wells.
Date: January 1, 1990
Creator: Kaback, D.S.; Looney, B.B.; Eddy, C.A. & Hazen, T.C.
Partner: UNT Libraries Government Documents Department

Study of Nitrate Stress in Desulfovibrio vulgaris Hildenborough Using iTRAQ Proteomics

Description: The response of Desulfovibrio vulgaris Hildenborough (DvH),a sulphate-reducing bacterium, to nitrate stress was examined usingquantitative proteomic analysis. DvH was stressed with 105 m M sodiumnitrate(NaNO3), a level that caused a 50 percent inhibition in growth.The protein profile of stressed cells was compared with that of cellsgrown in the absence of nitrate using the iTRAQ peptide labellingstrategy and tandem liquid chromatography separation coupled with massspectrometry (quadrupoletime-of-flight) detection. A total of 737 uniqueproteins were identified by two or more peptides, representing 22 percentof the total DvH proteome and spanning every functional category. Theresults indicate that this was a mild stress, as proteins involved incentral metabolism and the sulphate reduction pathway were unperturbed.Proteins involved in the nitrate reduction pathway increased. Increasesseen in transport systems for proline, glycine^ betaineandglutamateindicate that the NaNO3 exposure led to both salt stress and nitratestress.Up-regulation observed in oxidative stress response proteins (Rbr,RbO, etc.) and a large number of ABC transport systems as well as in iron^ sulphur -cluster-containing proteins, however, appear to be specific tonitrate exposure. Finally, a number of hypothetical proteins were amongthe most significant changers, indicating that there may be unknownmechanisms initiated upon nitrate stress in DvH.
Date: October 12, 2006
Creator: Redding, A.M.; Mukhopadhyay, A.; Joyner, D.; Hazen, T.C. & Keasling, J.D.
Partner: UNT Libraries Government Documents Department