Anilines Oxidation with Chlorine Dioxide in Wastewater

Oxidative behaviors of three toxic pollutants including aniline, p-toludine and p-chloroaniline with ClO2 in water were studied with HPLC. The removal rates of anilines were used as criteria in this experiment. Effects of the ClO 2 concentration, pH and reaction time on the removal rate of anilines were discussed. The results show that for 1mmol ·L-1 aniline, p-toludine and p-chloroaniline, the optimal process conditions were as follows: ClO2 concentration as 5mmol ·L-1, pH as 8, 8-9 and 7-8 and the reaction time as 60, 30 and 20min for aniline, p-toludine and p-chloroaniline respectively. The removal rates of anilines were higher than 90% , revealing that the oxidative method of ClO2 is very feasible and efficient for anilines removal. Two intermediates p-aminophenol and azobenzene were detected by means of GC-MS. And, the possible reaction pathway was proposed.