Wetting prevention in membrane distillation through superhydrophobicity and recharging an air layer on the membrane surface
Name
Lienhard_Wetting prevention Rezai MEMSCI_2016_1016_Revision_V5.5_DSPACE.pdf
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1.08 MB
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Author(s)
Rezaei, Mohammad
Samhaber, Wolfgang M.
Warsinger, David Elan Martin
Lienhard, John H.
Date Issued
February 2017
Journal
Journal of Membrane Science
Publisher
Elsevier
Citation
Rezaei, Mohammad et al. “Wetting Prevention in Membrane Distillation through Superhydrophobicity and Recharging an Air Layer on the Membrane Surface.” Journal of Membrane Science 530 (May 2017): 42–52 © 2017 Elsevier B.V.
Version
Author's final manuscript
Abstract
Although membrane distillation offers distinctive benefits in some certain areas, i.e., RO concentrate treatment, concentrating solutions in the food industry and solar heat utilization, the occurrence of wetting of the hydrophobic membrane hinders its potential industrial applications. Therefore, wetting prevention is a vital criterion particularly for the treatment of solutions with lower surface tension than water. The present work examines the effect of recharging air bubbles on the membrane surface for the wetting incidence when a surfactant (sodium dodecyl sulfate, SDS) exists in a highly concentrated NaCl aqueous solution. This study shows that the presence of the air bubbles on the surface of the superhydrophobic membrane in a direct contact membrane distillation setup inhibited the occurrence of wetting (similar to 100% salt rejection) even for high concentrations of the surface-active species (up to 0.8 mM SDS) in the feed solution while no undesirable influence on the permeate flux was observed. Introducing air into the feed side of the membrane displaces the liquid which partly tends to penetrate the macro porous structure with air bubbles and therefore increases the liquid entry pressure, and in addition, the simultaneous use of a superhydrophobic membrane enhances the solution contact angle.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
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Creative Commons Attribution-Noncommercial-Share Alike
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DOI of Published Version
https://doi.org/10.1016/J.MEMSCI.2017.02.013
