Oxidation of Chlorophenols by MnO<sub>2</sub> Supported on Kaolinite

Abstract

Chlorophenols (CPs) are of significant concern because of their wide use, toxicity and persistence in environments.In the present study, α-MnO 2 supported on kaolinite was used as an oxidant to oxidize three kinds of CPs, 4-chlorophenol (CP), 2, 4-dichlorophenol(DCP) and 2, 4, 6-trichlorophenol(TCP). XRD pattern showed that the synthetic MnO 2 has a poor crystallinity, and SEM results revealed that MnO 2 was evenly coated on kaolinite with a loading amount of 8.64mg/g. All three CPs were efficiently degraded by supported MnO 2 with a removal order of 2, 4, 6-TCP>2, 4-DCP>4-CP. The degradation of CPs obviously accompanied with the release of Mn 2+. Results also showed the increased oxidant's dosage promotes the removal of CPs. The reaction of CPs with MnO 2 is strictly pH-dependent, the removal of CPs decreased with pH increasing.