This study indicates that the dissolved-phase TCE was rapidly oxidizat by permanganate while the destruction of source free phase TCE appeared to be controlled by the rate of mass transfer of both permanganate and TCE toward their interface. The oxidation of dissolved-phase TCE by permanaganate had caused a significant decrease in pH (e.g., from 6.5 (background) to 3.5 (at approx pore volume)) and an increase in chloride (e.g., from 83 mg/L (background) to 380 mg/L (at approx 1 pore volume) in the extracted water in the beginning of the test. The downward migration of permanganate fronts near the aquitard provides evidences for the destruction of source free phase TCE. Two sets of soil cores collected near the aquitard at different times reveal that MnO_2 layers were formed above the source TCE zones and increased as the test proceeded.
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