Enhancement of surface properties and performance of reverse osmosis membranes after surface modification: A review

Abstract

Reverse osmosis (RO) membrane process has become the most promising technology for desalination to produce purified water. Among numerous polymeric materials used to fabricate RO membranes, aromatic polyamide thin film composite (TFC) membranes are dominant in commercial RO membrane processes because of their high salt rejection and water permeability as well as their excellent chemical, thermal, and mechanical stability. However, the major hindrance to the effective application of polyamide TFC RO membranes is membrane fouling. Furthermore, polyamide TFC RO membranes have limited stability to chlorine, which is commonly used as disinfect to control membrane biofouling. These two factors deteriorate membrane performance and shorten membrane life span.Membrane fouling depends strongly on membrane surface morphology and properties. Up to now, many physical or chemical surface modifications have been reported to alter the surface properties so as to improve the fouling resistance of the RO membranes. In this paper, different kinds of RO membranes fouling, chlorine effects, factors that influence RO membranes fouling, and the ways for reduction of fouling in RO membranes were discussed. Moreover, as a main part of this paper, all physical and chemical surface modification methods for fabricated polyamide TFC RO membranes were completely reviewed.