In-situ fouling mitigation and purification of complex oily wastewater durable superhydrophilic catalytic separation membrane based on salting-out effect

For complex oily wastewater, establishing multi-scale in-situ anti-fouling separation membrane materials can effectively mitigate membrane fouling and achieve wastewater purification. Based on this, this study prepared a multifunctional membrane material (PC/Co 3 S 4 @NW) that combines super-wetting properties with catalytic functionality. The membrane's superwetting property originates from hydrogel encapsulation, with salt precipitation enhancing the hydrogel's stability. The PC/Co 3 S 4 @NW is exceptional in superhydrophilicity and underwater oleophobicity, enabling efficient separation of oil-water mixtures (separation efficiency >97%) and oil-water emulsions (separation efficiency >95%). The catalyst loading imparts to the PC/Co 3 S 4 @NW membrane the ability to catalyze the degradation of aqueous organic pollutants, achieving removal rates exceeding 99.5% for various dyes. This degradation effectively mitigates the decline in separation flux caused by membrane fouling. Furthermore, during a continuous filtration process lasting 10 h, the PC/Co 3 S 4 @NW membrane consistently maintained a dye removal rate of over 93%. Radical scavenging tests and degradation kinetic testing elucidate the membrane's catalytic mechanism. What's more, the PC/Co 3 S 4 @NW membrane can achieve significant purification efficacy for complex actual oily wastewater. This in-situ separation-catalysis strategy offers a viable pathway for purifying complex oily wastewater and efficiently mitigating membrane fouling.