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Book Trichloroethylene Degradation in the Presence of Soil

Download or read book Trichloroethylene Degradation in the Presence of Soil written by Lisa M. Imbrogno and published by . This book was released on 1997 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Degradation of Tetrachloroethylene and Trichloroethylene Under Thermal Remediation Conditions

Download or read book Degradation of Tetrachloroethylene and Trichloroethylene Under Thermal Remediation Conditions written by Jed Costanza and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal remediation involves heating subsurface environments and collecting fluids in order to recover contaminants such as tetrachloroethylene (PCE) and trichloroethylene (TCE). While increasing subsurface temperature can lead to changes in the distribution of contaminants between the solid, liquid, and gas phases, there is also an increased potential for PCE and TCE to degrade. This work was performed to determine the rate of PCE and TCE degradation and products formed in laboratory-scale experiments designed to simulate thermal remediation conditions. The conditions during transport of gas-phase TCE were simulated using flow-through experiments in the temperature range from 60 to 800C. Degradation of TCE was not evident at temperatures of less than 240C; however, chloroacetic acids, which comprised less than 0.1% of the influent TCE on a carbon basis, were detected. At temperatures greater than 300C, TCE readily degraded where the identities of the degradation products were a function of oxygen and water content. With oxygen present, TCE degraded to form CO, phosgene, CO2 with minor amounts of hexachloroethane, PCE, and carbon tetrachloride. Increasing the amount of water vapor was found to decrease the amount of TCE degraded. Vapor recovery systems used during thermal treatments are anticipated to capture these TCE degradation products. However, the amount of missing carbon ... in experiments completed at 800C makes the prospect of recovering all TCE degradation products doubtful. Experiments were conducted using hermetically sealed ampules to simulate heating dissolved phase PCE and TCE over periods of up to 75 days. At 120C, the first-order TCE degradation half-life was 330 days and the degradation products included CO and CO2, glycolate, formate, and chloride. The rate of TCE disappearance was increased with the addition of 1% (wt.) goethite, which suggests that the presence of iron bearing soil minerals can increase rates of TCE degradation during thermal treatment. In contaminated field samples, TCE was found to degrade to form cis-1,2-dichloroethylene at 95C coincident with the formation of hydrogen gas. Degradation of PCE was not evident in field samples or in deionized water and is not expected to degrade during thermal remediation at temperatures below 95C.

Book Trichloroethylene Degradation by a Nitrifying Consortium in Soil

Download or read book Trichloroethylene Degradation by a Nitrifying Consortium in Soil written by Eugene Edward Dammel and published by . This book was released on 1997 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Effect of Metals and Nutrients on Trichloroethylene Degradation by Soil Cultures Stimulated by Methane

Download or read book Effect of Metals and Nutrients on Trichloroethylene Degradation by Soil Cultures Stimulated by Methane written by Kumar S. Kathinokkula and published by . This book was released on 2002 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Measuring the Kinetics of Trichloroethylene Degradation by Methanotrophic Bacteria in Differential Soil Bioreactors

Download or read book Measuring the Kinetics of Trichloroethylene Degradation by Methanotrophic Bacteria in Differential Soil Bioreactors written by Steven G. Hansen and published by . This book was released on 1992 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Trichloroethylene Contaminated Soil Clean up Using Surfactant based Separation Technology and Bioremediation

Download or read book Trichloroethylene Contaminated Soil Clean up Using Surfactant based Separation Technology and Bioremediation written by Sasikarn Chuahom and published by . This book was released on 2006 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surfactant-based separation technology and bioremediation was integrated to enhance the removal of trichloroethylene (TCE) from soil. In this system, cloud point extraction by non-ionic surfactant was conducted to separate high amount of TCE into the surfactant-rich phase and then bioremediation was integrated into the system by adding bacteria to co-metabolize the remaining TCE. Six surfactant systems including SURFONIC TDA-5, SURFONIC TDA-6, SURFONIC L24-7, NEODOL 91-5, NEODOL 91-6 without electrolyte addition and DTAB/DOWFAX (2:1 molar ratio) with 0.8 M NaCI were studied. These surfactants induced a phase separation with the surfactant-rich phase presented on top of the solution thus preventing the accumulation of surfactant on soil particles. The results found that SURFONIC TDA-6, SURFONIC L24-7, an NEODOL 91-6 did not inhibit TCE degradability of either Rhodococcus sp. L4 or Phodococcus sp. P3 bacteria while others killed the bacteria. Rhodococcus sp. L4 degraded TCE effectively in the presence of SURFONIC TDA-6, in which more than 58% of 10 ppm TCE was reduced within 24 hours compared to only 30% of TCE removal in control treatment (without the bacteria), SURFONIC TDA-6 was then selected for determining the optimal condition for TCE extraction consisting of equilibrium time, contact time between surfactant solution and soil and initial concentration of surfactant. The optimal condition for TCE extraction by cloud point technique were as followed; 72 hours of equilibrium time, 1 lour of contact time between soil and surfactant solution, and 70 mM of initial concentration of surfactant. These acquired conditions were later applied to compare the effectiveness of three TCE treatment processes including: (1) bioremediation, (2) surfactant extraction and (3) integrated technique. TCE removal efficiency was determined from the remaining TCE concentration in soil after treatment. The TCE removal efficiency of 100 ppm TCE contaminated soil by bioremediation, surfactant extraction and integrated technique were about 74%, 74% and 94%, respectively. Morever, TCE was mineralized as showed by the increase of chloride ions after remediation by bioremediation and integrated technique. When increased the amount of initial TCE to 300 ppm, the removal efficiency of the integrated technique was about 94% which was around 30% higher than either technique alone. The result found that soil remediation by the integrated technique had the highest TCE removal efficiency.

Book FATE AND DISPOSITION OF TRICHLOROETHYLENE IN SURFACE SOILS

Download or read book FATE AND DISPOSITION OF TRICHLOROETHYLENE IN SURFACE SOILS written by Thomas Joseph Walker and published by . This book was released on 1984 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: Trichloroethylene (TCE) is a widely detected contaminant in groundwater. This study investigated fate of TCE in two similar soils with differing organic carbon contents. TCE was applied to soil columns in one 5 or 10 m1 quantity, then eluted with 50 or 100 m1 of water/day. The 1.4% organic carbon soil retarded TCE elution more than did the 0.53% soil. Biodegradation of TCE in the soils, based on effluent TCE and chlorides, was not enhanced by addition of ammonia. Warburg studies showed TCE inhibited biological activity in unacclimated soil. Acclimated soil of both types from 2.5 and 15 inch depths showed degradation of TCE at 55 mg/1 but not 110 or 550 mg/1. No evidence of cis or trans-1,2-dichloroethylene was found in column effluents. Degradation (biological and abiotic) accounted for 0.3% or less of TCE. Volatilization accounted for 15.6-32.8% of TCE applied.

Book Degradation of Trichloroethylene TCE and Polychlorinated Biphenyls PCBs by Fe and Fe Pd Bimetals in the Presence of Surfactants and Cosolvents

Download or read book Degradation of Trichloroethylene TCE and Polychlorinated Biphenyls PCBs by Fe and Fe Pd Bimetals in the Presence of Surfactants and Cosolvents written by and published by . This book was released on 1997 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surfactants and cosolvents are being used to enhance the removal of dense non-aqueous phase liquids (DNAPL) such as trichloroethylene (TCE) and polychlorinated biphenyls (PCBS) from contaminated soils. However, the waste surfactant solution containing TCE and PCBs must be treated before it can be disposed. This study evaluated the use of zero-valence iron and palladized iron fillings on the dechlorination of TCE and a PCB congener in a dihexylsulfosuccinate surfactant solution. Batch experimental results indicated that TCE can be rapidly degraded by palladized iron filings with a half-life of 27.4 min. PCB was degraded at a slower rate than TCE with a half-life ranging from 100 min to 500 min as the concentration of surfactant increased. In column flow-through experiments, both TCE and PCBs degrade at an enhanced rate with a half-life about 1.5 and 6 min because of an increased solid to solution ratio in the column than in the batch experiments. Results of this work suggest that Fe-Pd filings may be potentially applicable for ex-situ treatment of TCE and PCBs in the surfactant solutions that are generated during surfactant washing of the contaminated soils.

Book Toxicological Profile for Trichloroethylene

Download or read book Toxicological Profile for Trichloroethylene written by and published by . This book was released on 1997 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Comparative Plant Uptake and Microbial Degradation of Trichloroethylene in the Rhizospheres of Five Plant Species

Download or read book Comparative Plant Uptake and Microbial Degradation of Trichloroethylene in the Rhizospheres of Five Plant Species written by Todd Alan Anderson and published by . This book was released on 1994 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Chlorinated Hydrocarbons Advances in Research and Application 2012 Edition

Download or read book Chlorinated Hydrocarbons Advances in Research and Application 2012 Edition written by and published by ScholarlyEditions. This book was released on 2012-12-26 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chlorinated Hydrocarbons—Advances in Research and Application: 2012 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Chlorinated Hydrocarbons. The editors have built Chlorinated Hydrocarbons—Advances in Research and Application: 2012 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Chlorinated Hydrocarbons in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Chlorinated Hydrocarbons—Advances in Research and Application: 2012 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Book Comparative Plant Uptake and Microbial Degradation of Trichloroethylene in the Rhizospheres of Five Plant Species Implications for Bioremediation of Contaminated Surface Soils

Download or read book Comparative Plant Uptake and Microbial Degradation of Trichloroethylene in the Rhizospheres of Five Plant Species Implications for Bioremediation of Contaminated Surface Soils written by and published by . This book was released on 1992 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study was to collect data that would provide a foundation for the concept of using vegetation to enhance in situ bioremediation of contaminated surface soils. Soil and vegetation (Lespedeza cuneata, Paspalum notatum, Pinus taeda, and Solidago sp.) samples from the Miscellaneous Chemicals Basin (MCB) at the Savannah River Site were used in tests to identify critical plant and microbiological variables affecting the fate of trichloroethylene (TCE) in the root zone. Microbiological assays including phospholipid acid analyses, and 14C-acetate incorporation were conducted to elucidate differences in rhizosphere and nonvegetated soil microbial communities from the MCB. The microbial activity, biomass, and degradation of TCE in rhizosphere soils were significantly greater than corresponding nonvegetated soils. Vegetation had a positive effect on microbial degradation of 14C-TCE in whole-plant experiments. Soils from the MCB containing Lespedeza cuneata, Pinus taeda, and Glycine max mineralized greater than 25% of the 14C- TCE added compared with less than 20% in nonvegetated soils. Collectively, these results provide evidence for the positive role of vegetation in enhancing biodegradation.