This paper investigated the individual effects of reverse salt flux and permeate flux on fouling behaviors of as-spun and annealed polybenzimidazole (PBI)-polyhedral oligomeric silsesquioxane (POSS)/polyacrylonitrile (PAN) hollow fiber membranes under forward osmosis (FO) and pressure retarded osmosis (PRO) processes. Two types of membrane fouling had been studied; namely, inorganic fouling (CaSO4·2H2O gypsum scaling) during FO operations and organic fouling (sodium alginate fouling) during PRO operations. It is found that gypsum scaling on the membrane surface may be inhibited and even eliminated with an increase in reverse MgCl2 flux due to competitive formations of MgSO4° and CaSO4·2H2O. In contrast, the increase of reverse NaCl flux exhibits a slight enhancement on alginate fouling in both FO and PRO processes. Comparing to the reverse salt flux, the permeate flux always plays a dominant role in fouling. Therefore, lesser fouling has been observed on the membrane surface under the pressurized PRO process than FO process because the reduced initial flux mitigates the fouling phenomena more significantly than the enhancement caused by an increase in reverse NaCl flux. © 2013 Elsevier B.V.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This research was funded by the Singapore National Research Foundation under its Competitive Research Program for the project entitled, "Advanced FO Membranes and Membrane Systems for Wastewater Treatment, Water Reuse and Seawater Desalination" (grant number: R-279-000-336-281) and was also supported by the Singapore National Research Foundation under its Environmental & Water Technologies Strategic Research Programme, administered by the Environment & Water Industry Programme Office (EWI) of the PUB under the project titled "Membrane Development for Osmotic Power Generation, Part 1. Materials Development and Membrane Fabrication" (1102-IRIS-11-01) and NUS grant no. R-279-000-381-279. Special thanks is given to Mr. Fengjiang Fu, Dr. Dave W. Mangindaan. The author, Si Cong Chen, would also thank the NUS Graduate School for Integrative Sciences & Engineering for the financial support of her PhD study.
ASJC Scopus subject areas
- Water Science and Technology
- Materials Science(all)
- Chemical Engineering(all)
- Mechanical Engineering