Double-Skinned Forward Osmosis Membranes for Reducing Internal Concentration Polarization within the Porous Sublayer
MetadataShow full item record
AbstractA scheme to fabricate forward osmosis membranes comprising a highly porous sublayer sandwiched between two selective skin layers via phase inversion was proposed. One severe deficiency of existing composite and asymmetric membranes used in forward osmosis is the presence of unfavorable internal concentration polarization within the porous support layer that hinders both (i) separation (salt flux) and (ii) the performance (water flux). The double skin layers of the tailored membrane may mitigate the internal concentration polarization by preventing the salt and other solutes in the draw solution from penetrating into the membrane porous support. The prototype double-skinned cellulose acetate membrane displayed a water flux of 48.2 L·m-2·h -1 and lower reverse salt transport of 6.5 g·m -2·h-1 using 5.0 M MgCl2 as the draw solution in a forward osmosis process performed at 22 °C. This can be attributed to the effective salt rejection by the double skin layers and the low water transport resistance within the porous support layer. The prospects of utilizing the double-selective layer membranes may have potential application in forward osmosis for desalination. This study may help pave the way to improve the membrane design for the forward osmosis process. © 2010 American Chemical Society.
CitationWang KY, Ong RC, Chung T-S (2010) Double-Skinned Forward Osmosis Membranes for Reducing Internal Concentration Polarization within the Porous Sublayer. Ind Eng Chem Res 49: 4824–4831. Available: http://dx.doi.org/10.1021/ie901592d.
SponsorsThe authors would like to thank King Abdullah University of Science and Technology (KAUST), Saudi Arabia, and National University of Singapore (NUS) for funding this research project with Grant Nos. R-279-000-265-597 and R-279-000-265-598. Special thanks are due to Dr. Yang Qian, Ms. Low Bee Ting, Ms. Zhang Jiyuan, and Ms. Zhang Sui for their valuable assistance.
PublisherAmerican Chemical Society (ACS)