(Georgia Institute of Technology, 2003-04)
Costanza, Jed; Pennell, Kurt D.; Mulholland, James A.
Removal of separate-phase organic liquids from the subsurface has been hypothesized to reduce the long-term contamination of ground-water resources. Thermal source zone treatment is one remedial method being used to recover organic liquids from the subsurface. In-situ oxidation of organic contaminants is thought to occur during thermal treatment, resulting in the formation of benign reaction byproducts including carbon dioxide and water. This work presents the results from an ongoing laboratory investigation of the chemical transformation of trichloroethylene (TCE), a common source zone contaminant, as a function of temperature. The objective of this study is to quantify the TCE degradation products formed in a laboratory-scale reactor containing three phases (air, water, and solids) heated over a temperature range from 22 to 480°C to simulate subsurface conditions under thermal source zone treatment. Preliminary experimental results show that TCE reacts to form tetrachloroethylene (PCE), an unwanted byproduct, at temperatures greater than 300°C. Future experimental efforts will focus on the effect of granular medium and moisture content on chemical transformations.