Highly efficient separation of yttrium from concentrated strontium aqueous solution by novel silica-based HDEHP-impregnating adsorbent

As the primary fission product in spent nuclear fuel being generally filed into the high-level liquid waste, the 90Sr recovered from the reprocessed nuclear fuel could be a significant source for producing 90Y nuclide (the decay daughter). It presents as one favorable therapeutic radionuclide candidate for radiolabeling of pharmaceuticals in widespread clinical application. Under this situation, a novel silica-based adsorbent (HDEHP/SiO2-P) was developed for selective separation of Y3+ from concentrated Sr2+ in aqueous solution. Batch adsorption process was investigated under different parameters of acid type and strength, contact time, temperature, ionic concentration and molar ratio etc. It was confirmed that, the HDEHP/SiO2-P had highly selective properties toward Y3+ over Sr2+ in different acidic medium (i.e., hydrochloric, nitric and acetic acid), with maximum adsorption capacity 34.05 mg Y3+/g. Sorption isotherms and uptake kinetics, were better fitting for Langmuir mono- molecular layer adsorption mode and the pseudo-second order (PSORE) kinetic model respectively. The sorbent shows high SFY/Sr of 1.93 x 103 even at a Sr-Y molar ratio of 2 x 103. Moreover, dynamic separation of trace amount of Y3+ from the concentrated Sr2+ aqueous solution was successfully validated by the column test, in which 100 % Y3+ was recovered. The produced eluate is characterized by a sharp elution curve without Sr trailing under high acidic conditions of 6 M HCl. All these results would promisingly promote the application of the developed material and chromatographic approach to facilely obtain the adequate quantities of 90Y with required radiochemical purity for its widespread clinical use.