DEGRADATION OF TRICHLOROETHYLENE BY PYRITE-GOETHITE AT ELEVATED TEMPERATURES

摘要

Thermal remediation involves heating subsurface regions to transfer contaminants from the non-aqueous, sorbed and dissolved phases into the gas phase for recovery by soil vapor extraction. The rate of contaminant degradation, potentially due to reactions catalyzed by iron oxide surfaces, is thought to increase after the subsurface has been heated to temperatures of up to 120oC. The objective of this study was to evaluate degradation rates of dissolved phase trichloroethylene (TCE) in the presence of solids that are commonly found in subsurface environments. The solids included 20-30 mesh sand from Ottawa, IL (U.S. Silica CO.) and research grade goethite collected from Grants County, NM (Ward’s Natural Science). The effect of solid-phase composition on TCE degradation rates and product formation was determined by incubating hermetically-sealed glass ampules at 25 and 120oC for periods of up to 290 days.