Phenol Removal from Water by Polyamide and AgCl Mineralized Thin-Film Composite Forward Osmosis Membranes.

This study systematically investigated phenol removal from water and phenol fouling of membranes in forward osmosis (FO) using thin-film composite (TFC) polyamide and silver chloride (AgCl) mineralized thin-film composite (MTFC) membranes. The influence of operating parameters (membrane orientation, phenol concentration, draw solution concentration, pH, and ionic strength) on phenol rejection and phenol adsorption to the membrane was investigated to elucidate the phenol transport behaviors in the FO process. Overall, phenol rejection improved with increased draw solution concentration or feed solution pH. At a feed solution pH of 11, TFC membranes exhibited their highest phenol rejection of 97.0% and MTFC membranes exhibited their highest phenol rejection of 98.8%. Phenol adsorption on the membrane surface may be related to the solute hydrophobic character, electrostatic interaction, and reverse salt diffusion. Six-hour fouling experiments show that the phenol fouling of FO membranes is reversible and easily cleaned by physical flushing. Additionally, compared with the TFC membranes, the MTFC membranes have an increased flux and rejection for phenol in FO. [ABSTRACT FROM AUTHOR]