Show simple item record

dc.contributor.authorQuattrini, Federico
dc.contributor.authorGalceran i Nogués, Josep
dc.contributor.authorDavid, Calin
dc.contributor.authorPuy Llorens, Jaume
dc.contributor.authorAlberti, Giancarla
dc.contributor.authorRey Castro, Carlos
dc.description.abstractThe time-evolution of Cd2+ ion sorption by Chelex 100 resin was studied in batch experiments as a function of time, pH, ionic strength, stirring rate, mass of resin and initial metal ion concentration. In the experimental conditions, the amount of resin sites are in excess with respect to the amount of metal ion, leading to extensive depletion of metal in bulk solution when equilibrium is reached. The data were described using a mixed control mass transport model in finite volume conditions (MCM) that includes explicitly both intraparticle and film diffusion steps. Exact numerical computations and a new approximate analytical expression of this model are reported here. MCM successfully predicts the influence of pH and ionic strength on the experimental Cd(II)/Chelex kinetic profiles (which cannot be justified by a pure film diffusion controlled mechanism) with a minimum number of fitting parameters. The overall diffusion coefficient inside the resin was modelled in terms of the Donnan factor and the resin/cation binding stability constant. The values of the latter coefficient as a function of pH and ionic strength were estimated from the Gibbs-Donnan model. Even though MCM is numerically more involved than models exclusively restricted to film or intraparticle diffusion control, it proves to be accurate in a wider range of values of the mass transfer Biot number and solution/resin metal ratios.
dc.description.sponsorshipThe authors gratefully acknowledge support for this research from the Spanish Ministry MINECO (Projects CTM2013-48967 and CTM2016-78798) and by the “Comissionat d'Universitats i Recerca de la Generalitat de Catalunya” (2014SGR1132). FQ acknowledges a grant from AGAUR.
dc.relation.isformatofVersió postprint del document publicat a:
dc.relation.ispartofChemical Engineering Journal, 2017, vol. 317, p. 810-820
dc.rightscc-by-nc-nd, (c) Elsevier, 2017
dc.subjectChelating resins
dc.subjectTrace metals
dc.subjectParticle diffusion control
dc.subjectFilm diffusion control
dc.subjectDGT passive sampler
dc.titleDynamics of trace metal sorption by an ion-exchange chelating resin described by a mixed intraparticle/film diffusion transport model. The Cd/Chelex case

Files in this item


This item appears in the following Collection(s)

Show simple item record

cc-by-nc-nd, (c) Elsevier, 2017
Except where otherwise noted, this item's license is described as cc-by-nc-nd, (c) Elsevier, 2017