Effect of humic-acid fouling on membrane distillation
Membrane distillation (MD) can concentrate non-volatile solutes or remove volatiles and dissolved gases from an aqueous feed. A microporous hydrophobic membrane provides a barrier between the hot feed and cold distillate. Although MD can operate at ambient pressure and moderate temperatures, use was...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
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2017
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| Online Access: | https://hdl.handle.net/10356/85720 http://hdl.handle.net/10220/43807 |
| _version_ | 1811687904248856576 |
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| author | Tan, Yong Zen Chew, Jia Wei Krantz, William B. |
| author2 | School of Chemical and Biomedical Engineering |
| author_facet | School of Chemical and Biomedical Engineering Tan, Yong Zen Chew, Jia Wei Krantz, William B. |
| author_sort | Tan, Yong Zen |
| collection | NTU |
| description | Membrane distillation (MD) can concentrate non-volatile solutes or remove volatiles and dissolved gases from an aqueous feed. A microporous hydrophobic membrane provides a barrier between the hot feed and cold distillate. Although MD can operate at ambient pressure and moderate temperatures, use waste heat, and treat wastewater via an MD-bioreactor, it has problems such as temperature polarization, liquid weeping to the distillate side, and membrane fouling. Prior studies speculated that fouling can add a heat- or mass-transfer resistance, or cause a vapor-pressure reduction owing to the Kelvin effect, but did not isolate these effects. This study confirms that the vapor-pressure depression owing to the concave interface in the small pores of the fouling layer is a dominant cause of the 25–63% flux reduction observed for humic-acid fouling on PTFE and PVDF membranes. This study underscores the importance of selecting MD membranes based on their pore-size distribution rather than just their nominal diameter in order to maximize the contribution of Knudsen diffusion. It suggests the development of dual-layer membranes having a thin hydrophilic layer with relatively large pores overlying a hydrophobic layer with a typical MD membrane structure in order to mitigate the vapor-pressure reduction owing to membrane fouling. |
| first_indexed | 2024-10-01T05:23:43Z |
| format | Journal Article |
| id | ntu-10356/85720 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T05:23:43Z |
| publishDate | 2017 |
| record_format | dspace |
| spelling | ntu-10356/857202020-03-07T11:35:28Z Effect of humic-acid fouling on membrane distillation Tan, Yong Zen Chew, Jia Wei Krantz, William B. School of Chemical and Biomedical Engineering Singapore Membrane Technology Centre Membrane Distillation Fouling Membrane distillation (MD) can concentrate non-volatile solutes or remove volatiles and dissolved gases from an aqueous feed. A microporous hydrophobic membrane provides a barrier between the hot feed and cold distillate. Although MD can operate at ambient pressure and moderate temperatures, use waste heat, and treat wastewater via an MD-bioreactor, it has problems such as temperature polarization, liquid weeping to the distillate side, and membrane fouling. Prior studies speculated that fouling can add a heat- or mass-transfer resistance, or cause a vapor-pressure reduction owing to the Kelvin effect, but did not isolate these effects. This study confirms that the vapor-pressure depression owing to the concave interface in the small pores of the fouling layer is a dominant cause of the 25–63% flux reduction observed for humic-acid fouling on PTFE and PVDF membranes. This study underscores the importance of selecting MD membranes based on their pore-size distribution rather than just their nominal diameter in order to maximize the contribution of Knudsen diffusion. It suggests the development of dual-layer membranes having a thin hydrophilic layer with relatively large pores overlying a hydrophobic layer with a typical MD membrane structure in order to mitigate the vapor-pressure reduction owing to membrane fouling. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) EDB (Economic Devt. Board, S’pore) 2017-09-27T07:25:30Z 2019-12-06T16:09:00Z 2017-09-27T07:25:30Z 2019-12-06T16:09:00Z 2016 Journal Article Tan, Y. Z., Chew, J. W., & Krantz, W. B. (2016). Effect of humic-acid fouling on membrane distillation. Journal of Membrane Science, 504, 263-273. 0376-7388 https://hdl.handle.net/10356/85720 http://hdl.handle.net/10220/43807 10.1016/j.memsci.2015.12.051 en Journal of Membrane Science © 2016 Elsevier B.V. |
| spellingShingle | Membrane Distillation Fouling Tan, Yong Zen Chew, Jia Wei Krantz, William B. Effect of humic-acid fouling on membrane distillation |
| title | Effect of humic-acid fouling on membrane distillation |
| title_full | Effect of humic-acid fouling on membrane distillation |
| title_fullStr | Effect of humic-acid fouling on membrane distillation |
| title_full_unstemmed | Effect of humic-acid fouling on membrane distillation |
| title_short | Effect of humic-acid fouling on membrane distillation |
| title_sort | effect of humic acid fouling on membrane distillation |
| topic | Membrane Distillation Fouling |
| url | https://hdl.handle.net/10356/85720 http://hdl.handle.net/10220/43807 |
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