Pressure retarded osmosis (PRO) is a promising technology to produce clean and sustainable osmotic energy from salinity gradient. Fresh water is of scarcity in Singapore; however, alternative sources of feed solutions and draw solutions are well explored. For the first time, seawater brine from the TuaSpring desalination plant and wastewater retentate from the NEWater plant were used in a state-of-the-art TFC-PES hollow fiber membrane PRO process. The highest power densities obtained with 1 M NaCl solution and seawater brine were 27.0 W/m2 and 21.1 W/m2 at 20bar, respectively, when deionized (DI) water was used as the feed solution. However, the highest power density dropped to 4.6W/m2 when wastewater retentate was used as the feed solution. Fouling on the porous substrate induced by the wastewater retentate was identified as the main cause of the reduction in the power densities, while the negative effects of seawater brine on the PRO performances were negligible. Both ultrafiltration (UF) and nanofiltration (NF) pretreatment were employed to mitigate fouling from the wastewater retentate, and the power densities were boosted to 6.6W/m2 and 8.9W/m2, respectively, beyond the power density of 5W/m2 proposed by Statkraft for the PRO process to be economical.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This research is supported by the National Research Foundation-Prime Minister's Office, Republic of Singapore, 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. The special thanks are due to TuaSpring Desalination Plant and Kranji NEWater Plant for their kind supply of SWBr and WWRe, Thanks are also due to Drs. G. Flan, X. Li, S. Zhang, and Miss S.C. Chen for their kind help,
ASJC Scopus subject areas
- Filtration and Separation
- Materials Science(all)
- Physical and Theoretical Chemistry