title: A spectroscopic characterization and quantification of m(III)/clay mineral outer-sphere complexes.
abstract: For the long-term safety assessment of deep radioactive waste repositories an understanding of the interactions of actinides with mineral surfaces at a molecular level is necessary. The retention/mobility of the released radionuclides is strongly dependent on sorption/desorption reactions at mineral surfaces. Thus, a quantitative understanding of the uptake mechanisms of actinides on clay minerals will make an important contribution to long-term safety assessments. Using time-resolved laser fluorescence spectroscopy (TRLFS), it was possible to differentiate between nonsorbed aquo ions and outer-sphere sorbed Cm(III) onto different montmorillonites. In addition, Cm(III)/clay outer-sphere complexation at different ionic strengths using NaCI as the background electrolyte is quantified. Finally, the results are verified by sorption model calculations.
authors.affiliation: Forschungszentrum Karlsruhe, Institut für Nukleare Entsorgung, Karlsruhe, Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Hartmann
authors.forename: Bart
authors.initials: B
authors.lastname: Baeyens
authors.forename: Michael H
authors.initials: MH
authors.lastname: Bradbury
authors.forename: Horst
authors.initials: H
authors.lastname: Geckeis
authors.forename: Thorsten
authors.initials: T
authors.lastname: Stumpf
mesh_terms: D008671:Actinoid Series Elements / Q000737:chemistry*; D000538:Aluminum Silicates / Q000737:chemistry*; D000077215:Clay; D006863:Hydrogen-Ion Concentration; D008903:Minerals / Q000737:chemistry*; D008956:Models, Chemical; D009994:Osmolar Concentration; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013997:Time Factors
chemical_list: D008671:Actinoid Series Elements; D000538:Aluminum Silicates; D008903:Minerals; D012996:Solutions; D000077215:Clay