Adsorption behavior and mechanism of isobutyl-BTP/SiO₂-P adsorbent for Am(III) and Ln(III) in nitrate solution

Porous isobutyl-BTP/SiO₂-P adsorbent was prepared to separate MA(III) from HLLW. The adsorption behavior of isobutyl-BTP/SiO₂-P toward ²⁴¹Am(III), Y(III) and Ln(III) in 0.01 M HNO₃-NaNO₃ solution was studied. Isobutyl-BTP/SiO₂-P showed high adsorption selectivity toward ²⁴¹Am(III) over Y(III) and Ln(III) fission products. Adsorption kinetics of Dy(III) followed pseudo-second order rate equation, and its adsorption isotherm matched the Langmuir isotherm equation well. Moreover, the adsorption product of Dy(III) on isobutyl-BTP/SiO₂-P was studied using extended X-ray absorption fine structure (EAXFS) method and Dy(isobutyl-BTP/SiO₂-P)₃³⁺ was supposed as the main adsorption species. (author)