Separation of Palladium along with Minor Actinides by isoBu-BTP/SiO2‑P Adsorbent from High-Level Liquid Waste

Aiming at the separation of Pd­(II) along with MA­(III) from high-level liquid waste, a porous silica based adsorbent isoBu-BTP/SiO2-P was prepared. The adsorption properties of isoBu-BTP/SiO2-P toward Pd­(II) were investigated. It was found that with the increase of HNO3 concentration, Pd­(II) adsorption ability increased initially as HNO3 concentration increased until 1 M, then remained unchanged as HNO3 concentration further increased. The adsorption kinetics and isotherm of Pd­(II) onto isoBu-BTP/SiO2-P fit well with the pseudo-second-order rate law and Langmuir adsorption model, respectively. The adsorption thermodynamic parameters revealed that the adsorption process was spontaneous and endothermic. A hot test utilizing isoBu-BTP/SiO2-P packed column was conducted and the simultaneous separation of Pd­(II) and MA­(III) was achieved from solution by using 0.01 M HNO3-0.1 M TU and 0.01 M HNO3-0.01 M DTPA as eluents, respectively. The Pd­(II) with isoBu-BTP/SiO2-P complex was illustrated to be 1:1 type by HRMS, while 1:3 Eu­(III) to isoBu-BTP complex was found by single-crystal X-ray diffraction.