A Review of Piezoelectric Effect-Based Self-Cleaning Membranes for Wastewater Treatment: Mechanisms and Perspectives

چکیده

Membrane fouling has long been recognized as the Achilles’ heel of membrane-based wastewater treatment technologies; a persistent challenge for which conventional mitigation strategies, owing to their fundamentally reactive nature and high energy demand, have largely failed to provide a sustainable solution. This review elucidates the paradigm shift brought about by the emergence of piezoelectric membranes as a self-actuated and dynamic antifouling platform—an advanced technology that transforms the membrane from a passive separation barrier into an active and responsive functional agent. By exploiting electromechanical coupling in inherently non-centrosymmetric structures such as poly(vinylidene fluoride) (PVDF), lead zirconate titanate (PZT), and quartz, these membranes are capable of converting ambient hydraulic or mechanical energy into localized electrical and physical stimuli. In this work, the multidimensional self-cleaning mechanisms are systematically dissected, ranging from in situ mechanical oscillations induced by the inverse piezoelectric effect under alternating current (AC) excitation, which disrupt concentration polarization, to the localized generation of ultrasonic waves for cake-layer disintegration, as well as piezocatalysis synergistically coupled with dielectrophoretic forces for the degradation of organic pollutants and microbial electroporation. Quantitative performance assessments under dynamic operating conditions demonstrate the remarkable efficacy of these systems in flux recovery (up to 98%) and fouling resistance mitigation. Finally, by identifying key bottlenecks—including the structural stability of hybrid matrices and the efficiency of energy conversion—a roadmap is proposed toward the development of self-powered membranes: intelligent systems that harvest the hydraulic energy of the feed stream and fundamentally shift fouling control from periodic remediation to continuous and proactive