Investigation towards salt rejection performance on thin film composite membrane prepared through single layer method and layer by layer method

Abstract

Forward osmosis (FO) membrane has becomes a promising membrane technology due to its lower energy consumption and high salt rejection performance. However, in prolong application, FO membrane is susceptible to internal concentration polymerization (ICP) that reduce water flux through the membrane. Therefore, layer by layer (LbL) method was proposed to improve the FO performance. This study focused on the effect of fabrication method to cast thin film composite (TFC) membrane using SL method and LbL method. The membranes were prepared using interfacial polymerization technique and tested through salt rejection experiment. Theoretically, LbL method should provide high salt rejection value as it is good at controlling the structures and thickness compare to SL method. However, from the testing, the results showed that the salt rejection value of TFC membrane using SL technique is higher (97.17%) compared to LbL technique (73.33%). Thus, it is suggested, co-casting method should be used towards the TFC membrane for future studies due to its advantageous over SL and LbL method.