432474 Controlled Oxidation of Trichloroethylene Using Polymer-Encapsulated Potassium Permanganate in the Presence of Hexavalent Chromium

Thursday, November 12, 2015: 12:30 PM
255E (Salt Palace Convention Center)
Jude Ighere1,2, Daniel Attoh1 and Ramesh Chawla1, (1)Chemical Engineering, Howard University, Washington, DC, (2)Intel Corporation

Trichloroethylene (TCE) oxidation under different environmental conditions, media and in co-existence with hexavalent chromium (Cr+6) was evaluated. The specific objectives were focused on the oxidation of trichloroethylene in soil and aqueous media using both unmodified-KMnO4 particles and poly methyl methacrylate (PMMA)-encapsulated KMnO4 in the presence and absence of hexavalent chromium. Molar ratios (P-values) of KMnO4 to TCE were used as a variable parameter in the TCE oxidation process. P-values of 2, 5 and 10 were investigated in aqueous media. Rate constant of 0.5M-1s-1 was obtained using unmodified KMnO4 in aqueous system. The extent of oxidation did not change with TCE concentration. In soil system, TCE oxidation requires large amount of KMnO4 to produce similar results as in aqueous system. Experiments indicated that except at high alkaline conditions, pH does not impact the extent of TCE oxidation. Also, the presence of Cr+6 did not inhibit TCE oxidation by KMnO4. Using controlled release application, the rate of TCE oxidation was reduced by PMMA-encapsulated KMnO4. Comparative study indicated an expectedly slow rate of TCE degradation using modified-KMnO4 but showed similar overall extent of oxidation for both modified and unmodified KMnO4. The application of the encapsulated matrix yielded 88 ± 3% TCE oxidation and a simultaneous Cr+6 reduction by ferrous ion (Fe+2) of 81 ± 2.1% in the same system. Controlled release of oxidant provides a useful tool to control relative reaction rates in multicomponent systems with potential applications to hazardous waste treatment.

Extended Abstract: File Not Uploaded