title: Sorption of Pu(VI) onto TiO2.
abstract: The sorption of Pu(VI) onto TiO(2) was studied as a function of pH (2-10) and Pu concentration (10(-8)-10(-4) M) under an N(2) atmosphere, in 0.016 and 0.1 M NaClO(4). A batch-wise method was used, in which pH was measured in separate experimental containers after removal of a sample to determine the amount of Pu that had been sorbed. As Pu is radioactive, it was used as a tracer and measured by liquid scintillation counting. No ionic strength dependence was discerned, which was taken as an indication of inner sphere complex formation. In the interval of pH 2-7 the system could be described by the formation of two positively charged surface complexes using a 1-pK Stern model. Sorption of the plutonyl ion (PuO(2)(2+)) and the first hydrolysis species (PuO(2)(OH)(+)) was estimated using FITEQL to logK(1)=6.9 and logK(2)=1.4, respectively.
authors.affiliation: Department of Materials and Surface Chemistry, Nuclear Chemistry, Chalmers University of Technology, SE-412 96, Göteborg, Sweden. mo@nc.chalmers.se
authors.forename: Mattias
authors.initials: M
authors.lastname: Olsson
authors.forename: Anna-Maria
authors.initials: AM
authors.lastname: Jakobsson
authors.forename: Yngve
authors.initials: Y
authors.lastname: Albinsson