title: Sorption of selenium oxyanions on TiO2 (rutile) studied by batch or column experiments and spectroscopic methods.
abstract: Selenium is a known toxic element released in the environment by anthropogenic activities. The present study is devoted to the aqueous sorption behaviour of selenium oxyanions (selenate and selenite) on a reference oxide surface, namely rutile TiO(2). Batch sorption kinetics and isotherms have been studied using different physico-chemical conditions of the solution (changes of pH and ionic strength). The sorption was favoured for both anions in acidic conditions, in agreement with a surface complexation mechanism and CD-MUSIC predictions. Spectroscopic investigations of the sorbed rutile powder were also consistent with such a mechanism. EXAFS spectra confirmed that for selenite anions, an inner-sphere mechanism was the most probable process observed. Dynamic sorption experiments using a column filled with rutile powder also substantiated that a part of the surface complexes follows the inner-sphere mechanism, but also evidenced that an outer-sphere mechanism cannot be excluded, especially for selenate anions.
authors: Laboratoire Réactions et Génie des Procédés, UPR CNRS n 3349, 1, rue Grandville BP 20451 54001 Nancy Cedex, France.
authors: Lenka
authors: L
authors: Svecova
authors: Manuel
authors: M
authors: Dossot
authors: Sébastien
authors: S
authors: Cremel
authors: Marie-Odile
authors: MO
authors: Simonnot
authors: Michel
authors: M
authors: Sardin
authors: Bernard
authors: B
authors: Humbert
authors: Christophe
authors: C
authors: Den Auwer
authors: Laurent J
authors: LJ
authors: Michot
mesh_terms: D000327:Adsorption; D000838:Anions / Q000032:analysis*; D004573:Electrolytes; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry; D007700:Kinetics; D012643:Selenium / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D000838:Anions; D004573:Electrolytes; D007477:Ions; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium; D012643:Selenium