Sorption of Eu(III) on quartz at high salt concentrations - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue Colloids and Surfaces A: Physicochemical and Engineering Aspects Année : 2019

Sorption of Eu(III) on quartz at high salt concentrations

Résumé

Sorption of Eu(III) onto quartz from highly saline solutions (up to 5 M NaCl) for pHc 2–9 ha s been studied by measuring sorption edges. The acid-base titrations of the silica surface suggest the rather unusual presence of two different sites that has been the object of recent discussions in the literature. Europium uptake results show the usual behaviour with a steep pH-edge and nearly complete removal at sufficiently high pH. Previous spectroscopic data on this system suggest the presence of two bidentate surface complexes with different proton stoichiometry. Based on this, a self-consistent Surface Complexation Model (SCM) was fitted to the full set of experimental data, from 0.1 to 5 M NaCl, using a coupled Pitzer/surface complexation approach. The Pitzer model was applied to aqueous species. A Basic Stern Model was used for interfacial electrostatics of the system, which includes ion-specific effects via ion-pair formation. Parameter fitting was done using the general parameter estimation software UCODE coupled to a modified version of FITEQL2 involving separate calculations of the respective ionic strength corrections. At high ionic strength (>1 M), the surface potential is strongly screened by ion-pair formation and the diffuse layer potential is negligibly low, which justifies the extension of the standard electrostatic model to these harsh conditions. Overall, our model is able to describe the full set of analysed data. To the knowledge of the authors this is the first comprehensive work studying solid surface titrations and cation uptake up to high salt levels and applying electrostatics models to describe the solid interface at these particular conditions. It is expected that these first systematic data acquisition along with the detailed modelling can serve as a benchmark for the modelling of future studies on sorption in highly saline systems.
Fichier principal
Vignette du fichier
Eu-SiO2_12_03_19.pdf (1.14 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-02380916 , version 1 (26-11-2019)

Identifiants

Citer

David Garcia, Johannes Lützenkirchen, Vladimir Petrov, Matthieu Siebentritt, Dieter Schild, et al.. Sorption of Eu(III) on quartz at high salt concentrations. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2019, 578, pp.123610. ⟨10.1016/j.colsurfa.2019.123610⟩. ⟨hal-02380916⟩
195 Consultations
160 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More