To develop high-flux and high-rejection forward osmosis (FO) membranes for water reuses and seawater desalination, we have fabricated polybenzimidazole (PBI) nanofiltration (NF) hollow fiber membranes with a thin wall and a desired pore size via non-solvent induced phase inversion and chemically cross-linking modification. The cross-linking by p-xylylene dichloride can finely tune the mean pore size and enhance the salt selectivity. High water permeation flux and improved salt selectivity for water reuses were achieved by using the 2-h modified PBI NF membrane which has a narrow pore size distribution. Cross-linking at a longer time produces even a lower salt permeation flux potentially suitable for desalination but at the expense of permeation flux due to tightened pore sizes. It is found that draw solution concentration and membrane orientations are main factors determining the water permeation flux. In addition, effects of membrane morphology and operation conditions on water and salt transport through membrane have been investigated. © 2008 Elsevier Ltd. All rights reserved.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The 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 numbers of R-279-000-265-597 and R-279-000-265-598. Thanks are also due to the reviewers who provide valuable suggestion, scientific explanations and comments.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.