Fouling control mechanisms of demineralized water backwash: Reduction of charge screening and calcium bridging effects

Handle URI:
http://hdl.handle.net/10754/561941
Title:
Fouling control mechanisms of demineralized water backwash: Reduction of charge screening and calcium bridging effects
Authors:
Li, Sheng; Heijman, Bas G J; Verberk, J. Q J C; Le-Clech, Pierre; Lu, Jie; Kemperman, Antoine J B; Amy, Gary L.; Van Dijk, Johannis C.
Abstract:
This paper investigates the impact of the ionic environment on the charge of colloidal natural organic matter (NOM) and ultrafiltration (UF) membranes (charge screening effect) and the calcium adsorption/bridging on new and fouled membranes (calcium bridging effect) by measuring the zeta potentials of membranes and colloidal NOM. Fouling experiments were conducted with natural water to determine whether the reduction of the charge screening effect and/or calcium bridging effect by backwashing with demineralized water can explain the observed reduction in fouling. Results show that the charge of both membranes and NOM, as measured by the zeta potential, became more negative at a lower pH and a lower concentration of electrolytes, in particular, divalent electrolytes. In addition, calcium also adsorbed onto the membranes, and consequently bridged colloidal NOM and membranes via binding with functional groups. The charge screening effect could be eliminated by flushing NOM and membranes with demineralized water, since a cation-free environment was established. However, only a limited amount of the calcium bridging connection was removed with demineralized water backwashes, so the calcium bridging effect mostly could not be eliminated. As demineralized water backwash was found to be effective in fouling control, it can be concluded that the reduction of the charge screening is the dominant mechanism for this. © 2011 Elsevier Ltd.
KAUST Department:
Water Desalination and Reuse Research Center (WDRC); Biological and Environmental Sciences and Engineering (BESE) Division
Publisher:
Elsevier BV
Journal:
Water Research
Issue Date:
Dec-2011
DOI:
10.1016/j.watres.2011.08.004
PubMed ID:
22014561
Type:
Article
ISSN:
00431354
Sponsors:
This research was funded by Senter Novem in the framework of the Innowator grants. Norit X-Flow By., the membrane manufacturer, the Netherlands, is gratefully acknowledged for providing UFC MS 0.8 membrane fibers. Evides. BV and Hatenboer-water. BV are appreciated for the cooperation in the DEMIFLUSH project.
Appears in Collections:
Articles; Water Desalination and Reuse Research Center (WDRC); Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorLi, Shengen
dc.contributor.authorHeijman, Bas G Jen
dc.contributor.authorVerberk, J. Q J Cen
dc.contributor.authorLe-Clech, Pierreen
dc.contributor.authorLu, Jieen
dc.contributor.authorKemperman, Antoine J Ben
dc.contributor.authorAmy, Gary L.en
dc.contributor.authorVan Dijk, Johannis C.en
dc.date.accessioned2015-08-03T09:34:36Zen
dc.date.available2015-08-03T09:34:36Zen
dc.date.issued2011-12en
dc.identifier.issn00431354en
dc.identifier.pmid22014561en
dc.identifier.doi10.1016/j.watres.2011.08.004en
dc.identifier.urihttp://hdl.handle.net/10754/561941en
dc.description.abstractThis paper investigates the impact of the ionic environment on the charge of colloidal natural organic matter (NOM) and ultrafiltration (UF) membranes (charge screening effect) and the calcium adsorption/bridging on new and fouled membranes (calcium bridging effect) by measuring the zeta potentials of membranes and colloidal NOM. Fouling experiments were conducted with natural water to determine whether the reduction of the charge screening effect and/or calcium bridging effect by backwashing with demineralized water can explain the observed reduction in fouling. Results show that the charge of both membranes and NOM, as measured by the zeta potential, became more negative at a lower pH and a lower concentration of electrolytes, in particular, divalent electrolytes. In addition, calcium also adsorbed onto the membranes, and consequently bridged colloidal NOM and membranes via binding with functional groups. The charge screening effect could be eliminated by flushing NOM and membranes with demineralized water, since a cation-free environment was established. However, only a limited amount of the calcium bridging connection was removed with demineralized water backwashes, so the calcium bridging effect mostly could not be eliminated. As demineralized water backwash was found to be effective in fouling control, it can be concluded that the reduction of the charge screening is the dominant mechanism for this. © 2011 Elsevier Ltd.en
dc.description.sponsorshipThis research was funded by Senter Novem in the framework of the Innowator grants. Norit X-Flow By., the membrane manufacturer, the Netherlands, is gratefully acknowledged for providing UFC MS 0.8 membrane fibers. Evides. BV and Hatenboer-water. BV are appreciated for the cooperation in the DEMIFLUSH project.en
dc.publisherElsevier BVen
dc.subjectBackwash wateren
dc.subjectFoulingen
dc.subjectNOMen
dc.subjectUltrafiltrationen
dc.subjectZeta potentialen
dc.titleFouling control mechanisms of demineralized water backwash: Reduction of charge screening and calcium bridging effectsen
dc.typeArticleen
dc.contributor.departmentWater Desalination and Reuse Research Center (WDRC)en
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.identifier.journalWater Researchen
dc.contributor.institutionDelft University of Technology, P.O. Box 5048, 2600 GA Delft, Netherlandsen
dc.contributor.institutionMembrane Technology Group, Institute of Mechanics, Processes and Control Twente (IMPACT), Faculty of Science and Technology, University of Twente, P.O. Box 217, NL-7500 AE Enschede, Netherlandsen
dc.contributor.institutionUNESCO Centre for Membrane Science and Technology, School of Chemical Engineering, The University of New South Wales, Sydney 2052, Australiaen
kaust.authorAmy, Gary L.en
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