Modeling of the interaction of Pu(VI) with the mixture of microorganism and clay

Onuki, Toshihiko; Ozaki, Takuo; Kozai, Naofumi   ; Sakamoto, Fuminori  ; Nankawa, Takuya ; Suzuki, Yoshinori; Francis, A. J.

In this study, we carried out experiments and model analysis of the transformation of Pu(VI) in a mixture of a common soil bacterium, Bacillus subtilis, and clay (kaolinite). A simplified kinetic model was proposed to describe the association of Pu with the mixture. In the model Pu(VI) and Pu(V) are assumed to be adsorbed on B. subtilis and kaoloinite. Pu(VI) is reduced to Pu(V) only in the solution because of simplification of the model, even though the reduction of Pu(VI) is actually occurred in solution, on B. subtilis and kaoloinite. Comparison of model estimation with experimental results suggest that kinetic simple model described the association of Pu(VI) with the mixture, and suggested that reduction of Pu(V) to Pu(IV) was mainly proceeded on the surface of B. subtilis in the mixture.