Effect of Surfactant Properties on the Performance of Forward Osmosis Membrane Process

Abstract

Wastewater treatments such as forward osmosis (FO) can be widely applied to separate or reject substances from secondary treated effluents. Experimental studies have investigated the influence of membrane fouling and operating conditions. Performance of FO is affected by membrane fouling characteristics, composition of the feed solution and operating conditions. Experiments were performed using an osmotic membrane (FO-4040) to investigate the influences of operating conditions on water flux and reverse salt selectivity. Surfactant content, cross-flow velocity, and pH of the feed solution were systematically investigated for their effects on FO performance. Results showed that higher cross-flow velocities, increase of the pH of the feed solution, and adding surfactant into the feed solution yielded higher water fluxes. Reverse salt selectivity also increased after adding surfactant to the feed solution but showed no significant increase at higher surfactant concentrations.

Keywords

• nonionic surfactant
• anionic surfactant
• omotically-membrane process