Engineering chlorine-resistant and boron selective reverse osmosis membrane: Strategies and challenges

Reverse osmosis (RO) membrane has experienced significant progress owing to its high reliability and efficiency in water purification. Nevertheless, the chlorine resistance and boron rejection performances of the RO membrane still below expectations. Constructing robust and selective RO membrane is highly desirable for addressing chlorine attack and achieving satisfactory boron removal efficiency. The current mainstream research direction focuses on the membrane design and modification for the RO membrane. This review discusses the development of RO thin film composite (TFC) membranes that deal with two major challenges, namely chlorine resistance and boron removal efficiencies. This review explores the modification mechanism, membrane properties and performances underlying these challenges. Innovative strategies established for improving chlorine resistance and boron rejection capability of TFC membrane are highlighted. The important membrane surface characteristics including charge density, hydrophilicity/hydrophobicity and surface chemical and their roles in rendering the desired properties for chlorine resistance and boron removal are discussed. This review provides imperative insight into the cutting-edge techniques and offers in-depth analyses of the research findings, thus opening up new revenues for further studies in this area.