Degradation of atrazine in water by Bi2MoO6 and visible light activated Fe3+/peroxymonosulfate coupling system

Abstract

In this study, the effects of ferric ion (Fe3+) on the degradation of atrazine (ATZ) in Bi2MoO6/peroxymonosulfate (PMS) system under visible light irradiation was investigated. With the addition of Fe3+, ATZ in the visible light/Bi2MoO6/PMS system degraded rapidly after 20 min treatment (removal rate > 99%). The enhancement of ATZ removal can be attributed to the role of Fe3+. As an electron transfer mediator, Fe3+ not only inhibits the recombination of photo-charges and prolongs the life of photogenerated carriers, but also promotes the activation of PMS by accelerating the electron transfer from Bi2MoO6 to PMS. The generation of •OH and SO4•− in the system was determined via electron paramagnetic resonance (EPR) technology and quenching experiments. Furthermore, the characterization of Bi2MoO6 before and after reaction, influence of the reaction parameters (i.e., catalyst and PMS dosages, Fe3+ and ATZ concentration, initial pH), influence of inorganic anions and humic acid, and the recyclability of catalyst in the vis/Bi2MoO6/PMS/Fe3+ system was also investigated. Additionally, the existence of Fe3+ also exhibits a wide selectivity for the degradation of different pollutants and high treatment efficiency. In general, the vis/Bi2MoO6/PMS/Fe3+ system demonstrated the potential as an efficient, economical, and environment-friendly water treatment process.