Surface complexation model of uranyl sorption on Georgia kaolinite Payne, T en_US Davis, J en_US Lumpkin, G en_US Chisari, R en_US Waite, David en_US 2021-11-25T14:17:13Z 2021-11-25T14:17:13Z 2004 en_US
dc.description.abstract The adsorption of uranyl on standard Georgia kaolinites (KGa-1 and KGa-1B) was studied as a function of pH (3-10), total U (1 and 10 mumol/1), and mass loading of clay (4 and 40 g/l). The uptake of uranyl in air-equilibrated systems increased with pH and reached a maximum in the near-neutral pH range. At higher pH values, the sorption decreased due to the presence of aqueous uranyl carbonate complexes. One kaolinite sample was examined after the uranyl uptake experiments by transmission electron microscopy (TEM), using energy dispersive X-ray spectroscopy (EDS) to determine the U content. It was found that uranium was preferentially adsorbed by Ti-rich impurity phases (predominantly anatase), which are present in the kaolinite samples. Uranyl sorption on the Georgia kaolinites was simulated with U sorption reactions on both titanol and aluminol sites, using a simple non-electrostatic surface complexation model (SCM). The relative amounts of U-binding >TiOH and >AlOH sites were estimated from the TEM/EDS results. A ternary uranyl carbonate complex on the titanol site improved the fit to the experimental data in the higher pH range. The final model contained only three optimised log K values, and was able to simulate adsorption data across a wide range of experimental conditions. The >TiCH (anatase) sites appear to play an important role in retaining U at low uranyl concentrations. As kaolinite often contains trace TiO2, its presence may need to be taken into account when modelling the results of sorption experiments with radionuclides or trace metals on kaolinite. (C) 2003 Elsevier B.V. All rights reserved. en_US
dc.identifier.issn 0169-1317 en_US
dc.language English
dc.language.iso EN en_US
dc.rights CC BY-NC-ND 3.0 en_US
dc.rights.uri en_US
dc.source Legacy MARC en_US
dc.subject.other adsorption en_US
dc.subject.other anatase en_US
dc.subject.other kaolinite en_US
dc.subject.other surface complexation en_US
dc.subject.other surface complexation en_US
dc.title Surface complexation model of uranyl sorption on Georgia kaolinite en_US
dc.type Journal Article en
dcterms.accessRights metadata only access
dspace.entity.type Publication en_US
unsw.relation.faculty Engineering
unsw.relation.ispartofissue 1-4 en_US
unsw.relation.ispartofjournal APPLIED CLAY SCIENCE en_US
unsw.relation.ispartofpagefrompageto 151-162 en_US
unsw.relation.ispartofvolume 26 en_US
unsw.relation.originalPublicationAffiliation Payne, T en_US
unsw.relation.originalPublicationAffiliation Davis, J en_US
unsw.relation.originalPublicationAffiliation Lumpkin, G en_US
unsw.relation.originalPublicationAffiliation Chisari, R en_US
unsw.relation.originalPublicationAffiliation Waite, David, Civil & Environmental Engineering, Faculty of Engineering, UNSW en_US School of Civil and Environmental Engineering *
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