Abstract
The objective of this study was to investigate the effect of polyvinyl alcohol（PVA）coating on chloride ion and boric acid rejection by thin-film composite polyamide reverse osmosis（RO）membranes. PVA-coated RO membranes were prepared by filtering an aqueous PVA solution through an ESPA2 commercial RO membrane and crosslinking the PVA by glutaraldehyde. Experimental results showed that the PVA coating decreased water permeability by 39 ％ under the experimental condition investigated in this study. However, regardless of the presence of PVA coating, comparison of solute rejection between ESPA2 and PVA-coated ESPA2 membranes at the given water flux showed that PVA coating does not affect solute rejection for both chloride ion and boric acid. These results indicated that the interaction between boric acid and PVA does not lead to an enhancement of boric acid partitioning into polyamide active layers.
