Effect of calcium on adsorptive removal of As(III) and As(V) by iron oxide-based adsorbents

Handle URI:
http://hdl.handle.net/10754/575601
Title:
Effect of calcium on adsorptive removal of As(III) and As(V) by iron oxide-based adsorbents
Authors:
Uwamariya, V.; Petruševski, Branislav; Lens, Piet Nl L; Amy, Gary L.
Abstract:
The effects of calcium on the equilibrium adsorption capacity of As(III) and As(V) onto iron oxide-coated sand (IOCS) and granular ferric hydroxide (GFH) were investigated through batch experiments, rapid small-scale column tests (RSSCT) and kinetics modelling. Batch experiments showed that at calcium concentrations≤20 mg/L, high As(III) and As(V) removal efficiencies by IOCS and GFH are achieved at pH 6. An increase of the calcium concentration to 40 and 80 mg/L reversed this trend, giving higher removal efficiencies at higher pH (8). The adsorption capacities of IOCS and GFH at an equilibrium arsenic concentration of 10 g/L were found to be between 2.0 and 3.1 mg/g for synthetic water without calcium and between 2.8 and 5.3 mg/g when 80 mg/L of calcium was present at the studied pH values. After 10 hours of filter run in RSSCT, approximately 1000 empty bed volumes, the ratios of C/Co for As(V) were 26% and 18% for calcium-free model water; and only 1% and 0.2% after addition of 80 mg/L of Ca for filter columns with IOCS and GFH, respectively. The adsorption of As(III) and As(V) onto GFH follows a second-order reaction, with and without addition of calcium. The adsorption of As(III) and As(V) onto IOCS follows a first-order reaction without calcium addition, and moves to the second-reaction-order kinetics when calcium is added. Based on the intraparticle diffusion model, the main controlling mechanism for As(III) adsorption is intraparticle diffusion, while surface diffusion contributes greatly to the adsorption of As(V).
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division
Publisher:
Informa UK Limited
Journal:
Environmental Technology
Issue Date:
25-Jun-2014
DOI:
10.1080/09593330.2014.934739
Type:
Article
ISSN:
09593330
Sponsors:
The authors thank the Netherlands Government for providing financial assistance through the Netherlands Fellowship Program under Grant no. 32000022.
Appears in Collections:
Articles; Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorUwamariya, V.en
dc.contributor.authorPetruševski, Branislaven
dc.contributor.authorLens, Piet Nl Len
dc.contributor.authorAmy, Gary L.en
dc.date.accessioned2015-08-24T08:33:56Zen
dc.date.available2015-08-24T08:33:56Zen
dc.date.issued2014-06-25en
dc.identifier.issn09593330en
dc.identifier.doi10.1080/09593330.2014.934739en
dc.identifier.urihttp://hdl.handle.net/10754/575601en
dc.description.abstractThe effects of calcium on the equilibrium adsorption capacity of As(III) and As(V) onto iron oxide-coated sand (IOCS) and granular ferric hydroxide (GFH) were investigated through batch experiments, rapid small-scale column tests (RSSCT) and kinetics modelling. Batch experiments showed that at calcium concentrations≤20 mg/L, high As(III) and As(V) removal efficiencies by IOCS and GFH are achieved at pH 6. An increase of the calcium concentration to 40 and 80 mg/L reversed this trend, giving higher removal efficiencies at higher pH (8). The adsorption capacities of IOCS and GFH at an equilibrium arsenic concentration of 10 g/L were found to be between 2.0 and 3.1 mg/g for synthetic water without calcium and between 2.8 and 5.3 mg/g when 80 mg/L of calcium was present at the studied pH values. After 10 hours of filter run in RSSCT, approximately 1000 empty bed volumes, the ratios of C/Co for As(V) were 26% and 18% for calcium-free model water; and only 1% and 0.2% after addition of 80 mg/L of Ca for filter columns with IOCS and GFH, respectively. The adsorption of As(III) and As(V) onto GFH follows a second-order reaction, with and without addition of calcium. The adsorption of As(III) and As(V) onto IOCS follows a first-order reaction without calcium addition, and moves to the second-reaction-order kinetics when calcium is added. Based on the intraparticle diffusion model, the main controlling mechanism for As(III) adsorption is intraparticle diffusion, while surface diffusion contributes greatly to the adsorption of As(V).en
dc.description.sponsorshipThe authors thank the Netherlands Government for providing financial assistance through the Netherlands Fellowship Program under Grant no. 32000022.en
dc.publisherInforma UK Limiteden
dc.subjectadsorptionen
dc.subjectarsenicen
dc.subjectcalciumen
dc.subjectGFHen
dc.subjectIOCSen
dc.titleEffect of calcium on adsorptive removal of As(III) and As(V) by iron oxide-based adsorbentsen
dc.typeArticleen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.identifier.journalEnvironmental Technologyen
dc.contributor.institutionUNESCO-IHE, PO Box 3015DA Delft, Netherlandsen
dc.contributor.institutionUniversity of Rwanda, PO Box 117Butare, Rwandaen
kaust.authorAmy, Gary L.en
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