Simultaneously Boosting Freshwater Productivity and Antifouling Efficacy of Membrane Distillation Through In Situ Micro‐Bubble Generation

Abstract Membrane distillation (MD), combining phase‐change purification with membrane separation, is a promising technology for treating industrial hypersaline wastewater with complex organics and residual oxidants (e.g., H ₂ O ₂ ). However, membrane fouling remains a prominent challenge that limits both productivity and durability. To address this challenge, a superhydrophobic membrane capable of in situ micro‐bubble generation is developed at the membrane‐liquid interface, effectively mitigating salt accumulation while enhancing vapor transfer. This is achieved by applying a surface coating of γ‐MnO ₂ and perfluorodecyltrichlorosilane (FDTS) on a commercial polyvinylidene difluoride (PVDF) membrane, which facilitates the decomposition of H ₂ O ₂ in the feed solution. The modified membrane evinced a flux enhancement of up to 35% for desalinating sodium chloride (NaCl) solution under various operating conditions, and its resistance to gypsum (CaSO ₄ ) fouling nearly doubled compared to the unmodified membrane. These improvements are attributed to the synergistic effects of the superhydrophobic property and the dynamic micro‐bubbles, which intensified turbulence and acted as nucleation barriers. Compared to recent studies, the developed membrane demonstrated superior productivity, antifouling, and cost‐effectiveness across various scenarios. The work provides a scalable and efficient approach for MD applications in hypersaline wastewater treatment.