Development of CuO coated ceramic hollow fiber membrane for peroxymonosulfate activation: a highly efficient singlet oxygen-dominated oxidation process for bisphenol a degradation

Abstract

A CuO coated ceramic hollow fiber membrane with dual functionalities of membrane filtration and peroxymonosulfate (PMS) activation was successfully constructed by applying phase-inversion and dip-coating technologies. The CuO coating condition was investigated, and the optimized CuO coated ceramic hollow fiber membranes (CuO@CHFMs) exhibited excellent catalytic activity for PMS activation to depredate bisphenol A (BPA) in the presence of humic acid (HA), chloride ions (Cl−) and bicarbonate (HCO3−). Based on the scavenger experiments and electron paramagnetic resonance (EPR) analyses, the non-radical reactive oxygen species - singlet oxygen (1O2), rather than sulfate radicals (SO4•-) or hydroxyl radicals (•OH), was elucidated as the primary reactive species responsible for the oxidation of BPA in the system. The redox circles of Cu(II)/Cu(I) on the CuO surface of the CuO@CHFMs are mainly responsible for PMS activation and a possible degradation pathway of BPA was proposed. Moreover, the CuO@CHFMs exhibited excellent stability and reusability without tedious catalyst separation/recovery processes. This study is meaningful for the development of novel catalytic membrane with PMS activation functionality in water treatment.