[Oxidative degradation of chlorinated hydrocarbons under anaerobic conditions]

Based on column experiments, the oxidative degradations of some chlorinated hydrocarbons under three less-reduced redox conditions were investigated. The results showed that in the presence of nitrate and manganese oxide, 1,2-dechloroethane (1,2-DCA) and vinyl chloride (VC) could be oxidized. The transformation rates of 1,2-DCA under denitrification and manganese reduction were 1.18/h and 0.54/h, respectively, while those of VC were 0.29/h and 0.15/h, respectively. In the presence of iron, degradation of VC was not clear. In addition, the degradation of 1,2-DCA was inhibited. For other chlorinated hydrocarbons, such as 1,1,1-trichloroethane, trichloroethene, cis-dichloroethene and trans-dichloroethene, no degradation occurred under the three studied redox conditions. Monochlorobenzene exhibited relative high removal in the columns, however, due to its high soil adsorption potential, it was not known yet whether microbial activities were involved.