Research on Oxidative Degradation of Toxic Pollutants in the Tannnary Dyeing Wastewater

摘要

Oxidative degradation behaviors of four Toxic pollutants including benzidine, o-tolidine, 3, 3' - dimethoxyl-benzidine and 3, 3 -dichlorobenzidine with chlorine dioxide in water were studied by detecting concentrations of benzidine with HPLC at regular intervals. The effect of the reactant molar ratio, pH and time of reaction on the removals of COD_(Cr) and benzidines were discussed. The optimal reaction conditions were presented. The results showed that the oxidative method of chlorine dioxide was feasible and efficient for benzidines degradation. The removal rate of COD_(Cr) reached 65%, and the degradations of benzidines were more than 90%. Azobenzene, hydrazobenzene and benzoquinone were detected by IR and GC/MS as intermediates. The reaction mechanism of benzidine oxidized with chlorine dioxide in water was proposed.