Fabrication of nanocomposite forward osmosis hollow fiber membrane for low reverse salt flux by modification of active layer via co-extrusion with graphene oxide

One of the rising technology forward osmosis (FO) process enables to reduce the cost of seawater desalination. As such as reverse osmosis process, water transfers through the semi-permeable membranes which are rejected to salts. However, the driving force of FO is not a hydraulic pressure gradient but an osmotic pressure gradient. To get a successful FO process, the membrane of FO should have high salts rejection features, high water permeability, and stability. Graphene oxide (GO) contained membranes are well known for alternative FO membranes due to its high water permeability property. However, another property of GO in membrane fabrication was verified in our study. It was found in our research that reverse salt flux was significantly reduced to 0.06 mol m(-2) h(-1) using 2.0 M NaCl draw solution when GO was applied to the active layer of the membrane. Although there have been occasional reports of the use of GO to improve reverse salt flux performance rather than water flux performance improvement. In our study, however, GO was applied only to the localized active layer, resulting in a remarkably reduced reverse salt flux results. In addition, GO was used for the fabrication of hollow fiber membranes.