A novel malonamide grafted polystyrene-divinyl benzene resin for extraction, pre-concentration and separation of actinides

A new chelating polymeric extraction chromatographic resin was prepared by chemical anchoring of N,N′-dimethyl-N,N′-dibutyl malonamide (DMDBMA) with chloromethylated Merrifield resin®. The grafted resin exhibited stronger binding for hexavalent and tetravalent actinides such as U(VI), Th(IV) and Pu(IV) over trivalent actinides, viz. Am(III) and Pu(III). Batch studies on solid phase extraction performed over a wide range of acid solution (0.01-6 M HNO3) revealed that ternary mixer of uranium, americium and plutonium or thorium, americium and plutonium could be separated from each other at 1 M HNO3. Desorption of U(VI), Pu(IV) and Am(III) from the loaded resin was efficiently carried out using 0.1 M α-HIBA, 0.25 M oxalic acid and 0.01 M EDTA, respectively. Quantitative pre-concentration of actinide ions such as Th(IV) and U(VI) was possible from 3 M HNO3 solution. The practical utility of the grafted resin was evaluated by uranium sorption measurements in several successive cycles. The sorption efficiency of the resin with respect to uranyl ion remained unchanged even after 30 days of continuous use. The surface morphology of the resin was monitored with the help of scanning electron microscopy (SEM) technique.