Surface Modification of Reverse Osmosis Membranes for Enhanced Boron Removal and Fouling Resistance

The trade-off between selectivity and permeability as well as membrane fouling are major obstacles of seawater reverse osmosis (SWRO) membranes. Surface grafting of a functional layer on a thin-film composite (TFC) membrane is one of the most promising and versatile strategies to address the above problems. In this work, 3-amino-1,2-propanediol (APD) and tobramycin (TOB) were grafted on the commercial RO membrane SW30XLE surface to improve the boron removal rate and fouling resistance. The optimized TFC-TOB2/APD10 membrane exhibited a 33.4% increase in permeate flux, while it maintained a high NaCl rejection of 98.0%. Compared with the SW30XLE membrane, the boron rejection of the TFC-TOB2/APD10 membrane enhanced from 84.2 to 92.2%. Besides, the obtained membrane exhibited excellent antifouling properties, including organic fouling resistance, scaling control, and bactericidal capacity. Our work paved a new way for fabrication of high-performance RO membranes with enhanced permselectivity and antifouling properties, which are greatly desired in SWRO desalination.