Peroxymonosulfate activation by octahedral Cu2O for Orange I degradation via radical and non-radical pathways

In this study, cubic Cu2O (c-Cu2O) and octahedral Cu2O (o-Cu2O) were prepared through a simple method and applied to activate peroxymonosulfate (PMS) for the degradation of Orange ? (O?). o-Cu2O exhibited excellent activity for PMS activation with 85.68 % of O? being removed within 30 min, and its catalytic activity remained high even if it was used repeated six times. The effects of PMS concentration, initial pH, anions (Cl-, HCO3- and NO3-) and natural organic matter (NOM) on O? degradation in the o-Cu2O/PMS system were investigated. The mechanism study implied that O? was oxidized via radical (SO4 center dot-, center dot OH and O-2(center dot-)) and non-radical (O-1(2) and electron transfer) pathways in the o-Cu2O/PMS system. This work provides an interesting insight into PMS activation by Cu-based catalysts for wastewater treatment.