Oxidative degradation of pentachlorophenol by permanganate for ISCO application

ABSTRACTPotassium permanganate (KMnO4) has been an effective technology for the in situ chemical oxidation (ISCO) of many organic compounds including chlorinated alkanes and alkenes, but it has rarely been applied for oxidizing aromatic organochlorines. This study confirms the ability of permanganate to oxidize an aromatic chlorinated compound, pentachlorophenol (PCP), in an efficient manner at neutral pH. The rate of the reaction between KMnO4 and PCP was calculated and the results indicated that the reaction between PCP and permanganate is relatively fast with a second-order rate constant k″ ∼ 30 M−1 s−1. Besides the kinetic aspect, the authors identified the main reaction by-products, and proposed a possible reaction mechanism scheme. The general pathway shows the formation of chlorinated intermediates, and ultimately, the complete mineralization to chloride, water, and CO2 confirmed by total organic carbon and chloride measurement in solution. Flow-through column experiments, consisting of flushing a ...