Applications of Potassium Permanganate in the Oxidative Degradation of Trichloroethylene

Abstract

The scope of this study was to determine techniques to remediate trichloroethylene contamination under different environmental conditions, media and in co-existence with chromium. The specific objectives were focused on the oxidation of trichloroethylene (TCE) in soil and aqueous media using both unmodified KMnO4 particles and poly (methyl methacrylate), PMMA encapsulated KMnO 4 in the presence and absence of hexavalent chromium, Cr(VI). Molar ratios (p-values) of KMnO 4 to TCE were used as a determining factor in the TCE oxidation process. p-values of 2, 5 and 10 were investigated in aqueous media and an approximately 0.5 M -1 ·s -1 rate constant was obtained using unmodified KMnO 4 in aqueous system. The extent of oxidation did not change with TCE concentration. In soil system, TCE oxidation requires a large amount of KMnO 4 to produce similar results as in aqueous system. pH experiments indicate that except at high alkaline condition, pH does not impact the extent of TCE oxidation. Also, the presence of Cr(VI) did not hinder TCE oxidation by KMnO 4 . Using controlled release application, the rate of TCE oxidation was reduced by PMMA encapsulated KMnO 4 . Comparative study indicated an expectedly slow rate of TCE degradation using modified KMnO 4 but similar overall extent of oxidation for both modified and unmodified KMnO 4 . The application of the encapsulated matrix yielded 88% ± 3% TCE oxidation and a simultaneous 81% ± 2.1% Cr(VI) reduction by ferrous ion in the same system.