Construction of Co0.5Mn0.5Fe2O4 Spinel and Immobilized PVDF-Membrane for Confined Catalytic Flow Removal of Refractory Organics

Peroxymonosulfate (PMS) based on heterogeneous catalytic reaction is a promising advanced oxidation process (AOP) for the removal of refractory contaminants. However, it remains challenging owing to the decreasing catalytic oxidation efficiency induced by powder catalyst loss and insufficient mass transfer. In this study, spinel ferrite Co0.5Mn0.5Fe2O4 was successfully prepared and further immobilized on commercial polyvinylidene fluoride (PVDF) membrane. Both of the powder and immobilized catalysts were used as PMS activators for the decolorization of Rhodamine B. Within a 30 min reaction time, Co0.5Mn0.5Fe2O4 powder catalyst achieved removal efficiency of 80% for tetracycline hydrochloride and 100% for RhB. The Co0.5Mn0.5Fe2O4–PVDF membrane with a pore diameter of 0.1 μm exhibited excellent catalytic performance, achieving 100% RhB decolorization after seven filtration cycles. Quenching experiments and electron paramagnetic resonance (EPR) analysis demonstrated that RhB decolorization degradation involved both radical and non-radical pathway. This study proposed a porous membrane-based catalytic strategy for AOPs. The results suggest that smaller membrane pore diameters may contribute to an enhanced oxidation performance, providing new insights into the design of catalytic membrane systems.