Engineering antifouling reverse osmosis membranes: A review

Over the past decades, water scarcity and security have significantly stimulated the advances of reverse osmosis (RO) technology, which dominates the global desalination market. However, deterioration of membrane separation performance caused by inevitable fouling, including organic fouling, inorganic fouling, colloidal fouling and biofouling, calls for improved RO membranes with more durable antifouling properties. In this review, we analyze the correlations between membrane properties (e.g. surface chemistry, morphology, hydrophilicity, and charge) to antifouling performance. We evaluate the three key strategies for engineering fouling resistant thin film composite RO membranes, namely: (1) substrate modification before interfacial polymerization, (2) incorporating (hydrophilic/biocidal/antifouling) additives into the selective layer during interfacial polymerization, and (3) post (surface) modification after interfacial polymerization. Finally, we offer some insights and future outlooks on the strategies for engineering next generation of high performance RO membranes with durable fouling resistance. This review provides a comprehensive, state-of-the-art assessment of the previous efforts and strategies as well as future research directions for engineering antifouling RO membranes.