Synergic extraction of Am(III) and Eu(III) in N,N-dioctyl-2-hydroxyacetamide-bis(2-ethylhexyl)phosphoric acid solvent system

The present paper reports the extraction behavior of Am(III) and Eu(III) from nitric acid medium in a binary extractant system composed of a neutral extractant, namely N,N-dioctyl-2-hydroxyacetamide (DOHyA) and an acidic extractant, namely bis(2-ethylhexyl)phosphoric acid (HDEHP) present in n-dodecane (n-DD) diluent. The effect of nitric acid, extractant, and nitrate ion concentration on the distribution ratio of Am(III) and Eu(III) was studied in 0.2 M DOHyA + 0.25 M HDEHP/n-DD and the results were compared with those obtained in the individual solvent system namely 0.2 M DOHyA/n-DD and 0.25 M HDEHP/n-DD. Synergic extraction of Am(III) and Eu(III) was observed in a binary solution and it was confirmed by slope analysis of extraction data and FT-IR spectroscopy. The present study also explored the feasibility of separating trivalent actinides from chemically similar lanthanides present in simulated high-level liquid waste (SHLLW) using the combined solvent system. A separation factor of Eu(III) over Am(III) of about 10 was achieved. (C) 2017 Elsevier B.V. All rights reserved.