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/APD(10) 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/APD(10) 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.

Automated summary

This study demonstrates that surface grafting of a functional layer on commercial RO membranes can enhance the boron removal rate and fouling resistance of seawater reverse osmosis (SWRO) membranes. The optimized membrane showed improved permeate flux, high NaCl rejection, enhanced boron rejection, and excellent antifouling properties, paving the way for high-performance RO membranes with enhanced permselectivity and antifouling properties in SWRO desalination.