Highly Efficient Extraction Chromatography Resins Containing Dendrimers with DGA Groups in Ionic Liquid for Actinide Uptake

High Sorption and Selective Extraction of Actinides from Aqueous Solutions

The selective elimination of long-lived radioactive actinides from complicated solutions is crucial for pollution management of the environment. Knowledge about the species, structures and interaction mechanism of actinides at solid–water interfaces is helpful to understand and to evaluate physicochemical behavior in the natural environment. In this review, we summarize recent works about the sorption and interaction mechanism of actinides (using U, Np, Pu, Cm and Am as representative actinides) on natural clay minerals and man-made nanomaterials. The species and microstructures of actinides on solid particles were investigated by advanced spectroscopy techniques and computational theoretical calculations. The reduction and solidification of actinides on solid particles is the most effective way to immobilize actinides in the natural environment. The contents of this review may be helpful in evaluating the migration of actinides in near-field nuclear waste repositories and the mobilization properties of radionuclides in the environment.

Actinide ion uptake from acidic radioactive feeds using an extraction chromatographic resin containing a branched dialkyl amide

A dialkyl amide with branched alkyl group, viz. N,N-di(2-ethylhexyl)-propionamide (D2EHPrA) was used as the organic extractant in an extraction chromatographic resin prepared for the first time and evaluated for the separation of uranium from acidic feeds. The distribution coefficient measurements, carried out at varying HNO₃ concentrations, indicated an increase in the UO₂²⁺ ion sorption with increasing nitric acid concentration. The UO₂²⁺ ion sorption kinetics and sorption isotherms with this resin were investigated in details. The column studies indicated that 8.3 mg of uranium could be loaded on a 2.1 cm³ column bed volume containing 0.35 g resin. Batch distribution data for other actinides such as Np⁴⁺ and Pu⁴⁺ indicated that the resin can also be used for effective separation of these metal ions from acidic feeds. Though the resin showed effectiveness for Np and Pu, detailed investigations dealing with macro concentrations of metal ions (in gm quantities) were restricted to uranium only due to hazardous nature of plutonium and limited availability of neptunium. The encouraging results reported in this work is an indication of the possible application of this resin for the recovery or pre-concentration of UO₂²⁺, Np⁴⁺ and Pu⁴⁺ ions from large volumes of aqueous solutions of moderate acidity.