Pore-functionalized ceramic membrane with isotropically impregnated cobalt oxide for sulfamethoxazole degradation and membrane fouling elimination: Synergistic effect between catalytic oxidation and membrane separation

In this study, a pore-functionalized ceramic membrane with isotropically impregnated cobalt oxide (CoCM) was prepared via an in-situ self-sacrificed template method and applied for sulfamethoxazole (SMX) degradation by peroxymonosulfate (PMS) activation under a dead-end membrane filtration mode. The physical and chemical properties of the membranes were characterized via FESEM, AFM, XRD and XPS. Results indicated that Co3O4 had been impregnated into the macropores uniformly throughout the whole ceramic membrane without pore blocking. The formation of Co-O-Al bonding inhibited the leaching of cobalt during the filtration while the hydroxyl group Co-OH played a crucial role during the radical generation. The contact angle of CoCM decreased, resulting in a higher pure water permeability as compared to the original ceramic membrane. The catalytic degradation of SMX showed that its removal efficiency could be influenced by both contact time and PMS dosage. CoCM exhibited superior antifouling property during the humic acid (HA) removal study. The stability and regeneration of CoCM were investigated. Furthermore, the radical quenching experiment was conducted and the concentration of sulfate radical was quantitatively estimated. Finally, the PMS activation as well as organics removal mechanism in CoCM via the synergistic coupling of catalytic Co3O4 and membrane separation were proposed.