U(VI) sorption on illite in the presence of carbonate studied by cryogenic time-resolved laser fluorescence spectroscopy and parallel factor analysis; Comparison with trivalent lanthanides

Mei, H.  ; 青柳 登   ; 斉藤 拓巳*; 杉浦 佑樹  ; 石寺 孝充 ; 田中 万也  ; 舘 幸男  

Mei, H.; Aoyagi, Noboru; Saito, Takumi*; Sugiura, Yuki; Ishidera, Takamitsu; Tanaka, Kazuya; Tachi, Yukio

The sorption of U(VI) and trivalent lanthanides on illite at different pH and dissolved inorganic carbon (DIC) levels was investigated. The obvious inhibition effect of DIC on U(VI) and trivalent lanthanides sorption was revealed from the macroscopic batch experimental results. The formation of carbonate-containing sorption complexes was needed to be considered in the updated 2-site protolysis non-electrostatic surface complexation and cation exchange model to reproduce the experimental results. Based on the Parallel Factor Analysis analysis on the cryogenic time-resolved laser fluorescence spectroscopy spectra, the formation of ternary carbonate-containing sorption complexes was successfully identified. Identification of the sorption species adds more credibility to the predictive sorption model, which provides more confidence in the safety assessment of deep geological disposal.