Cobalt-copper layered double hydroxide incorporated sepiolite dynamic membranes for catalytic oxidation of organic pollutants

Dynamic membranes (DMs) can effectively mitigate ultrafiltration membrane fouling by forming a dynamic barrier layer. However, DMs still face challenges in balancing separation efficiency, antifouling capacity, and regeneration frequency during practical applications. Herein, we propose a novel catalytic DM synergistically integrated with sepiolite (SEP) and cobalt-copper layered double hydroxide (Co-Cu-LDH). The prepared membrane exhibited a three-dimensional (3D) fibrous SEP network integrated within the substrate membrane, embedding with a Co-Cu-LDH catalyst layer. This structure significantly enhanced peroxymonosulfate (PMS) activation, leading to the generation of hydroxyl radical, superoxide radical, sulfate radical and singlet oxygen species. The LDH-SEP DM/PMS system achieved superior performance in treating secondary effluent, removing 92.3 % of dissolved organic carbon. Due to the synergistic effect of foulant interception and catalytic oxidation, the LDH-SEP DM exhibited excellent antifouling performance. Following three cycles filtration of secondary effluent, the membrane flux dropped by only 10 %, with the flux recovery rate of 99 %. Membrane fouling mechanism has also been changed, and the formation of cake filtration was significantly delayed. Overall, this work not only advances the mechanistic understanding of PMS activation via Co-Cu-LDH, but also provides a scalable strategy for designing multifunctional membranes tailored for high-efficiency, low-maintenance water purification systems.