Abstract
Recent studies show that osmotically driven membrane processes may be a viable technology for desalination, water and wastewater treatment, and power generation. However, the absence of a membrane designed for such processes is a significant obstacle hindering further advancements of this technology. This work presents the development of a high performance thin-film composite membrane for forward osmosis applications. The membrane consists of a selective polyamide active layer formed by interfacial polymerization on top of a polysulfone support layer fabricated by phase separation onto a thin (40 μm) polyester nonwoven fabric. By careful selection of the polysulfone casting solution (i.e., polymer concentration and solvent composition) and tailoring the casting process, we produced a support layer with a mix of finger-like and sponge-like morphologies that give significantly enhanced membrane performance. The structure and performance of the new thin-film composite forward osmosis membrane are compared with those of commercial membranes. Using a 1.5 M NaCl draw solution and a pure water feed, the fabricated membranes produced water fluxes exceeding 18 L m2-h-1, while consistently maintaining observed salt rejection greater than 97%. The high water flux of the fabricated thin-film composite forward osmosis membranes was directly related to the thickness, porosity, tortuosity, and pore structure of the polysulfone support layer. Furthermore, membrane performance did not degrade after prolonged exposure to an ammonium bicarbonate draw solution. © 2010 American Chemical Society.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3812-3818 |
| Number of pages | 7 |
| Journal | Environmental Science & Technology |
| Volume | 44 |
| Issue number | 10 |
| DOIs | |
| State | Published - May 15 2010 |
| Externally published | Yes |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: The work was supported by a Graduate Fellowship (to N.Y.Y.) made by the Environment and Water Industrial Development Council of Singapore; the WaterCAMPWS, a Science and Technology Center of Advanced Materials for the Purification of Water with Systems under the National Science Foundation Grant No. CTS-0120978; Oasys Water Inc.; and the KAUST-Cornell Center for Energy and Sustainability. We thank Eric Hoek and his research group at UCLA for useful guidance on protocols for interfacial polymerization.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.