Mechanism-Specific Fouling Mitigation via Tunable Resonance-Based Magnetic Vibrations in Ultrafiltration Membranes

Abstract

Fouling remains one of the most significant challenges in membrane-based separation processes, reducing productivity and increasing operational costs. This study introduces resonance-based magnetic membrane vibration as a nondestructive, real-time antifouling strategy, where membranes are excited at their natural frequencies to selectively mitigate fouling. Two magnetic membrane configurations were investigated: a centralized magnetic membrane (CMM), with iron particles concentrated at the center, and a scattered magnetic membrane (SMM), with particles distributed across the surface. These distinct distributions produced different morphologies, natural frequencies, and fouling behaviors. The first natural frequencies of CMM and SMM were 10 and 15 Hz, with threshold pressures of 18 and 35 psi, respectively, indicating higher intrinsic fouling resistance for SMM. For CMM at 10 psi, vibration at the first natural frequency reduced 6 h flux decline from 24.5 to 7.5%. Operation at 85 Hz, corresponding to the (3,1) vibration mode, reduced initial flux decline from 33 to 19%, targeting pore-blocking fouling. A sequential multifrequency strategy, 85 Hz for the first 15 min followed by 10 Hz, combined both advantages, reducing overall flux decline to 11.4%. These results establish a framework for mechanism-specific, real-time antifouling control in membrane filtration systems.