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dc.contributor.authorTow, Emily W.
dc.contributor.authorLienhard, John H.
dc.date.accessioned2017-10-02T19:07:52Z
dc.date.available2017-10-02T19:07:52Z
dc.date.issued2017-09
dc.date.submitted2017-08
dc.identifier.issn0376-7388
dc.identifier.urihttp://hdl.handle.net/1721.1/111677
dc.description.abstractHigh pressure is often considered to be the cause of the high fouling propensity of reverse osmosis (RO) relative to forward osmosis (FO). Several experimental studies have shown that alginate fouling is more susceptible to cleaning in FO than in RO, but the theory that foulant compaction causes this disparity seems to be contradicted by the incompressibility of alginate hydrogels. In addition, the effect of hydraulic pressure on fouling in osmotic membrane desalination has never been experimentally isolated, because fixed-flux comparisons at different hydraulic pressures require different draw solution osmotic pressures. In this study, a new approach to isolating the effect of hydraulic pressure on alginate fouling and cleaning is introduced: operating FO with elevated but equal feed and draw hydraulic pressures. The same concentration of sodium chloride is used as the draw solution in all trials to eliminate possible effects of draw solution osmotic pressure on membrane fouling or cleaning. Theoretical modeling of the effect of alginate foulant compaction on flux reveals that foulant compaction should accelerate flux decline with low salinity feeds but retard flux decline at high salinity. However, in low-salinity alginate fouling trials, for which foulant compaction should accelerate flux decline, the measured flux decline rate was not affected by hydraulic pressure. Furthermore, when fouled membranes were cleaned by increasing the feed velocity and reducing the draw osmotic pressure, there was no apparent relationship between hydraulic pressure and cleaning effectiveness. Finally, in situ visualization of foulant removal during the cleaning process revealed no difference in foulant removal mechanisms between different hydraulic pressures. These findings demonstrate that alginate gel compaction by high feed hydraulic pressure does not occur and suggest that other explanations should be sought for FO's high fouling resistance relative to RO.en_US
dc.description.sponsorshipNational Science Foundation (U.S.) (Grant 1122374)en_US
dc.language.isoen_US
dc.publisherElsevieren_US
dc.relation.isversionofhttps://doi.org/10.1016/j.memsci.2017.09.010en_US
dc.rightsCreative Commons Attribution-NonCommercial-NoDerivs Licenseen_US
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/en_US
dc.sourceProf. Lienharden_US
dc.titleUnpacking compaction: Effect of hydraulic pressure on alginate foulingen_US
dc.typeArticleen_US
dc.identifier.citationTow, Emily W., and Lienhard V, John H. “Unpacking Compaction: Effect of Hydraulic Pressure on Alginate Fouling.” Journal of Membrane Science 544 (December 2017): 221–233 © 2017 Elsevier B.V.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Mechanical Engineeringen_US
dc.contributor.mitauthorTow, Emily W.
dc.contributor.mitauthorLienhard, John H.
dc.relation.journalJournal of Membrane Scienceen_US
dc.eprint.versionAuthor's final manuscripten_US
dc.type.urihttp://purl.org/eprint/type/JournalArticleen_US
eprint.statushttp://purl.org/eprint/status/PeerRevieweden_US
dspace.orderedauthorsTow, Emily W.; Lienhard V, John H.en_US
dspace.embargo.termsNen_US
dc.identifier.orcidhttps://orcid.org/0000-0002-0606-713X
dc.identifier.orcidhttps://orcid.org/0000-0002-2901-0638
dspace.mitauthor.errortrue
mit.licensePUBLISHER_CCen_US


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