A novel hierarchical catalytic ceramic membrane for removal of sulfamethoxazole by peroxymonosulfate in complex water matrices: the advantages of the membrane-based oxidative degradation system

Abstract

Peroxymonosulfate (PMS)-based advanced oxidation process (PMS-AOP) is a promising technology for water decontamination. However, the application of PMS-AOP is limited due to the susceptibility of traditional batch reaction systems to impurity interference and low mass transfer efficiency, which makes the membrane-based catalytic system an excellent alternative. In this study, a hierarchical catalytic ceramic membrane coupled PMS-AOP system was constructed. In the membrane-based catalytic system, the directional flow carrying the reactants accelerated the contact between the PMS and the catalytic components, the spatial confinement effect shortened the mass-transfer distance between the reactants, and the tortuous structure ensured the sufficiency of the catalytic reaction. The system achieved a high degradation efficiency of 85 % for sulfamethoxazole (SMX) in a continuous degradation reactor with a flow rate of 79.4 Lm⁻²h⁻¹, while demonstrating high customizability, broad spectrum and environmental tolerance. Furthermore, the selectivity of the system was improved by the addition of a separating layer to isolate interfering substances, resulting in SMX degradation efficiencies of >80 % in both humic acid solution and actual wastewater, while also achieving total organic carbon (TOC) removal rates of >70 %. Finally, the possible degradation pathways of SMX were proposed through theoretical calculations, revealing the hierarchical catalytic ceramic membrane coupled SR-AOP system holds significant promise for treating micropollutants in complex aqueous matrices, thereby reducing their environmental toxicity.