Adsorption of Some Typical Fission Products onto a Novel Macroporous Silica-based Dialkyl Derivative of Pyridine Impregnated Material

A macroporous silica-based multidentate soft-ligand 2,6-bis(5,6-di(iso-hexyl)-1,2,4-triazine-3-yl)pyridine (BDIHTP) material, BDIHTP/SiO2-P, was synthesized by impregnating and immobilizating BDIHTP into the pores of the SiO2-P particles. The adsorption behavior of some typical fission products Mo(VI), Zr(IV), Ru(III), Pd(II), Rh(III), and a part of rare earths La(III), Ce(III), Nd(III), Eu(III), Gd(III), Dy(III), Er(III), Yb(III), and Y(III) contained in highly active liquid waste (HLW) onto BDIHTP/SiO2-P was investigated. The effects of contact time and the concentration of HNO3 in the range of 0.3M to 5.0M were examined. The BDIHTP/SiO2-P materials showed excellent adsorption ability and high selectivity for Pd(II) greater than all of the tested metals. It was contributed to the effective complexation of Pd(II), a soft-Lewis acid and an electron-pair acceptor, with BDIHTP, a soft-Lewis base and an electron-pair donor. The chromatographic partitioning of the tested metals from 1.0M HNO3 by BDIHTP/SiO2-P packed column was performed. Pd(II) was effectively eluted with 0.2M thiourea-0.1M HNO3 and then separated from the others. The results are beneficial to partitioning of the long-lived minor actinides and Pd(II) together from HLW by the BDIHTP/SiO2-P materials.