Activation of peroxymonosulfate by natural molybdenite for the degradation of atrazine

Abstract

In this work, molybdenite was used as a catalyst to activate peroxymonosulfate (PMS) for atrazine (ATZ) degradation. First, the effects of molybdenite dosage (0.05-0.30 g/L), PMS dosage (0.02-0.15 mM) and the initial pH (3.0-11.0) in the aqueous solution on the ATZ degradation were investigated in the molybdenite/PMS system. The maximum degradation efficiency of ATZ (95.0%) after 10 min treatment was obtained at the molybdenite dosage of 0.2 g/L, PMS dosage of 0.08 mM and initial pH of 6.4. The control experiments suggested that molybdenite, which activate PMS had better performance than commercial molybdenum disulfide. It was found that the degradation efficiency of ATZ under the optimal parameters was only 41.2% in the commercial molybdenum disulfide/PMS system. The free radicals in the molybdenite/PMS system were studied by quenching experiment. The results showed that both SO 4 • and HO • were existed in the molybdenite/PMS system. In general, this study provided a natural catalyst for PMS activation and would urge us re-evaluate the capacity of natural materials as catalysts.