Biopolymer-based membranes and their application in per- and polyfluorinated substances removal: Perspective review

Over the past 2 decades, per- and polyfluoroalkyl substances (PFAS) have attracted considerable attention due to their widespread occurrence and adverse effects on both the environment and human health. PFAS possess strong carbon‑fluorine bonds that confer exceptional chemical stability and resistance to natural degradation; their fluorinated chains are highly hydrophobic and oleophobic, while their polar functional groups contribute to amphiphilic behavior and water solubility. Certain PFAS thus pose serious risks to living organisms, especially mammals. Membrane filtration is recognized as a particularly effective technique, achieving removal efficiencies greater than 99 % for long-chain-PFAS (including anionic, cationic, and zwitterionic PFAS molecules). However, many conventional membrane processes rely on petroleum-based polymers and non-biodegradable materials which lead to significant sustainability concerns. The disposal of these materials harms the environment and contributes to secondary pollution. In this review, biopolymers are presented as alternatives and their different sources are categorized and discussed in detail. Further, the latest applications of commercial membranes for PFAS removal are discussed and compared with those of biopolymer-based membranes (BBMs). Finally, recommendations for advancing PFAS removal using BBMs are provided, and current knowledge gaps are highlighted. This manuscript therefore underscores the importance of evolving membrane technology within a circular economy framework.