Minor Actinides Partitioning: Uptake of Palladium with Triazine-Containing Adsorbent under the Framework of SPMP Process

To remove Pd­(II), a new triazine-containing silica adsorbent, BisDiOTP@SiO2–P, was prepared. The synthesis was achieved by impregnation in situ and immobilization of a multinitrogen ligand, BisDiOTP, into the pores of the SiO2–P support. The uptake of typical metals Sr­(II), Pd­(II), Li­(I), Na­(I), Cs­(I), K­(I), Rb­(I), and Ba­(II) onto BisDiOTP@SiO2–P was investigated. The effects of contact time and HNO3 concentration from 0.4 to 5.0 M were studied. The strong uptake ability and selectivity of BisDiOTP@SiO2–P for Pd­(II) was indicated by six cycles of the batch uptake and desorption. The removal efficiency was always more than 99.2% for Pd­(II) and less than 0.15% for others. In light of the results of batch experiments, the removal of Pd­(II) from a simulated 1.0 M HNO3 was performed using BisDiOTP@SiO2–P as a stationary phase by extraction chromatography. Pd­(II) adsorbed by BisDiOTP@SiO2–P was effectively desorbed with 0.2 M thiourea. An efficient removal of Pd­(II) by BisDiOTP@SiO2–P was achieved. Some valuable data in chemical separation engineering of Pd­(II) under the framework of SPMP process were obtained. It is promising to simultaneous removal of Pd­(II) and MAs­(III) from highly active liquid waste by the SPMP process developed.