Zeolites for nitrosamine and pharmaceutical removal from demineralised and surface water: Mechanisms and efficacy

Handle URI:
http://hdl.handle.net/10754/562111
Title:
Zeolites for nitrosamine and pharmaceutical removal from demineralised and surface water: Mechanisms and efficacy
Authors:
De Ridder, David J.; Verberk, J. Q J C; Heijman, Sebastiaan G J; Amy, Gary L.; Van Dijk, Johannis C.
Abstract:
Zeolites with a high Si/Al ratio can be used as selective adsorbents in water treatment, targeting organic micropollutants which are removed poorly with activated carbon. Due to size exclusion, many Natural Organic Matter (NOM) components cannot access the pores, thus limiting adsorption competition between organic micropollutant and NOM. Furthermore, zeolite channel diameters are close to molecule diameters, which results in strong van der Waals interaction. MOR200 and ZSM5, the two most hydrophobic zeolites, showed the highest removal of neutral nitrosamines in demineralised water, with higher efficacy than activated carbon. DAY and MOR30, which were relatively hydrophilic zeolites, did not show appreciable removal of any of the nitrosamines. When nitrosamines were adsorbed from surface water, there was no influence of competition with, or pore blockage by, NOM components on nitrosamine removal for ZSM5 zeolite, in contrast to activated carbon. Repulsion of negatively charged pharmaceuticals was significant for ZSM5, which had a Si/Al ratio of 80. MOR200 had a Si/Al ratio of 200, indicating a lower Al content than ZSM5 and, as such, a lower negative surface charge. Charge effects were not observed for MOR200. A relationship was found between the Stokes diameter of the pharmaceuticals and nitrosamines, and their removal by ZSM5 and MOR200, indicating that a "close fit" adsorption mechanism is more likely than hydrophobic interaction in these zeolites. Due to their selective nature, adsorption on zeolites should only be considered as an additional treatment step to existing processes, dedicated for the removal of specific organic micropollutants. Less specific treatment techniques, such as activated carbon filtration, are still required to ensure a broad barrier for organic micropollutants in water treatment. © 2012 Elsevier B.V. All rights reserved.
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division
Publisher:
Elsevier BV
Journal:
Separation and Purification Technology
Issue Date:
Mar-2012
DOI:
10.1016/j.seppur.2012.01.025
Type:
Article
ISSN:
13835866
Sponsors:
This research is financially supported by VEWIN, the association of drinking water companies in the Netherlands. Any opinions, findings, conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the opinion of the supporting organisation.
Appears in Collections:
Articles; Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorDe Ridder, David J.en
dc.contributor.authorVerberk, J. Q J Cen
dc.contributor.authorHeijman, Sebastiaan G Jen
dc.contributor.authorAmy, Gary L.en
dc.contributor.authorVan Dijk, Johannis C.en
dc.date.accessioned2015-08-03T09:45:03Zen
dc.date.available2015-08-03T09:45:03Zen
dc.date.issued2012-03en
dc.identifier.issn13835866en
dc.identifier.doi10.1016/j.seppur.2012.01.025en
dc.identifier.urihttp://hdl.handle.net/10754/562111en
dc.description.abstractZeolites with a high Si/Al ratio can be used as selective adsorbents in water treatment, targeting organic micropollutants which are removed poorly with activated carbon. Due to size exclusion, many Natural Organic Matter (NOM) components cannot access the pores, thus limiting adsorption competition between organic micropollutant and NOM. Furthermore, zeolite channel diameters are close to molecule diameters, which results in strong van der Waals interaction. MOR200 and ZSM5, the two most hydrophobic zeolites, showed the highest removal of neutral nitrosamines in demineralised water, with higher efficacy than activated carbon. DAY and MOR30, which were relatively hydrophilic zeolites, did not show appreciable removal of any of the nitrosamines. When nitrosamines were adsorbed from surface water, there was no influence of competition with, or pore blockage by, NOM components on nitrosamine removal for ZSM5 zeolite, in contrast to activated carbon. Repulsion of negatively charged pharmaceuticals was significant for ZSM5, which had a Si/Al ratio of 80. MOR200 had a Si/Al ratio of 200, indicating a lower Al content than ZSM5 and, as such, a lower negative surface charge. Charge effects were not observed for MOR200. A relationship was found between the Stokes diameter of the pharmaceuticals and nitrosamines, and their removal by ZSM5 and MOR200, indicating that a "close fit" adsorption mechanism is more likely than hydrophobic interaction in these zeolites. Due to their selective nature, adsorption on zeolites should only be considered as an additional treatment step to existing processes, dedicated for the removal of specific organic micropollutants. Less specific treatment techniques, such as activated carbon filtration, are still required to ensure a broad barrier for organic micropollutants in water treatment. © 2012 Elsevier B.V. All rights reserved.en
dc.description.sponsorshipThis research is financially supported by VEWIN, the association of drinking water companies in the Netherlands. Any opinions, findings, conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the opinion of the supporting organisation.en
dc.publisherElsevier BVen
dc.subjectAdsorptionen
dc.subjectNitrosamineen
dc.subjectPharmaceuticalen
dc.subjectZeoliteen
dc.titleZeolites for nitrosamine and pharmaceutical removal from demineralised and surface water: Mechanisms and efficacyen
dc.typeArticleen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.identifier.journalSeparation and Purification Technologyen
dc.contributor.institutionDelft University of Technology, P.O. Box 5048, 2600 GA Delft, Netherlandsen
kaust.authorAmy, Gary L.en
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