A review on membrane fouling and anti-fouling modification strategies of PVDF membranes in oil–water separation

Abstract

The treatment of oily wastewater, characterized by complex compositions and diverse oil droplet sizes, poses a critical challenge for environmental protection and resource recycling. Membrane separation technology, especially polyvinylidene fluoride (PVDF) membranes, has emerged as a promising solution due to its low energy consumption, simplicity, and compact system design, as well as PVDF membranes’ excellent mechanical properties, chemical stability, and extensive research focus. This review comprehensively presents the state-of-the-art advances in understanding fouling mechanisms and optimizing the anti-fouling performance of PVDF membranes for oil–water separation. It covers fundamental fouling theories and key evaluation parameters for membrane fouling, and systematically elaborates on modification strategies: bulk modification (incorporating additives during preparation via phase inversion, electrospinning, and combined crystallization and diffusion (CCD) to optimize overall performance) and surface modification (post-formation tuning using biomolecules, layered double hydroxides (LDHs), and surface patterning to enhance surface properties). Overall, this review aims to provide insights into the fundamental science and engineering aspects underlying PVDF membrane fouling and anti-fouling modification, as well as the challenges and opportunities to guide further advances in developing high-performance, anti-fouling PVDF membranes for efficient oily wastewater treatment.