Title:
Degradation of Tetrachloroethylene and Trichloroethylene under Thermal Remediation Conditions

dc.contributor.advisor Pennell, Kurt D.
dc.contributor.author Costanza, Jed en_US
dc.contributor.committeeMember carolyn ruppel
dc.contributor.committeeMember D. Webster
dc.contributor.committeeMember James Mulholland
dc.contributor.committeeMember Lawrence Bottomley
dc.contributor.department Civil and Environmental Engineering en_US
dc.date.accessioned 2006-01-18T22:15:18Z
dc.date.available 2006-01-18T22:15:18Z
dc.date.issued 2005-08-26 en_US
dc.description.abstract 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 (~17%) 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. en_US
dc.description.degree Ph.D. en_US
dc.format.extent 2616176 bytes
dc.format.mimetype application/pdf
dc.identifier.uri http://hdl.handle.net/1853/7485
dc.language.iso en_US
dc.publisher Georgia Institute of Technology en_US
dc.subject Trichloroethylene
dc.subject Tetrachloroethylene
dc.subject Degradation
dc.subject Thermal en_US
dc.title Degradation of Tetrachloroethylene and Trichloroethylene under Thermal Remediation Conditions en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.corporatename School of Civil and Environmental Engineering
local.contributor.corporatename College of Engineering
relation.isOrgUnitOfPublication 88639fad-d3ae-4867-9e7a-7c9e6d2ecc7c
relation.isOrgUnitOfPublication 7c022d60-21d5-497c-b552-95e489a06569
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