Sugarcane juice concentration using a novel aquaporin hollow fiber forward osmosis membrane

Abstract In this work, the performance of a commercially available aquaporin HFFO membrane was studied for concentrating the sugarcane juice by adopting appropriate UF pretreatment technique. The influences of draw and feed solution flowrates, draw concentration and its direction of flow such as co-current or counter-current on water and reverse solute flux was evaluated in batch mode. The specific reverse solute flux for counter-current mode was found to be less compared to co-current mode of operation. Improved draw solution (NaCl) flowrate increased the water flux with reduced specific reverse solute flux. The FS concentration ratio was 1.65 within 12 min of batch FO operation by using 100 g L−1 draw solution. Membrane fouling was studied systematically with appropriate membrane cleaning strategy. The effect of UF clarified and raw sugarcane juice on FO membrane fouling was calculated and it was found that raw sugarcane juice led to severe membrane fouling that reduced water permeability after 60 min of operation. The membrane fouled by UF clarified juice was able to regenerate by DI water wash for 30 min, however in the case of membrane fouled by raw juice, an additional 0.1 M NaOH wash was required.