Synthesis of a Novel Silica-Based Macroporous Polymer Containing TODGA Chelating Agent and Its Application in the Chromatographic Separation of Mo(VI) and Zr(IV) from Diethylenetriaminepentaacetic Acid

A novel silica-based N,N,N',N'-tetraoctyl-3-oxapentane-l,5-diamide (TODGA) chelating polymeric material (TODGA/SiO2-P) was synthesized by impregnating TODGA into -50 mm of spherical SiO2-P particles for separating Mo(VI) and Zr(IV) from a HNO3 solution containing 0.05 M diethylenetriaminepentacetic acid (DTPA) in minor actinides recovery by extraction chromatography (MAREC) process. The adsorption of TODGA/SiO2-P for Mo(VI) and Zr(IV) was investigated by examining the influence of HNO3 and DTPA concentrations. It was found that HNO3 concentration from 0.3M to 9 M either with or without 0.05M DTPA had a strong effect on the adsorption of Mo(VI) and Zr(IV) towards TODGA/SiO2-P. In the absence of 0.05 M DTPA, both the adsorption of Mo(VI) and Zr(IV) decreased with an increase in the concentration of HNO3 from 0.3 M to 3 M and then gradually increased. In the presence of 0.05 M DTPA, Zr(IV) showed scarcely any adsorption towards TODGA/SiO2-P below 2 M HNO3 and was gradually adsorbed from 2M to 3M HNO3 while Mo(VI) showed almost no absorption.