Room temperature ionic liquid diluent for the mutual separation of europium(III) from americium(III)

The extraction behavior of Eu(152+154)(III) and Am-241(III) in a solution of bis(2-ethylhexyl)phosphoric acid (D2EHPA) or bis(2-ethylhexyl)diglycolamic acid (HDEHDGA) in the ionic liquid, 1-octyl-3-methylimidazolium bis(trifluoromethanesulphonyl)imide (omimNTf(2)), was studied at 298 K. The extractant HDEHDGA was synthesized and characterized by IR, H-1 NMR and mass spectroscopy. The effect of various parameters such as the concentrations of nitric acid, D2EHPA, HDEHDGA and diethylenetriaminepentaacetic acid (DTPA) on the extraction behavior of Am-241(III) and Eu(152+154)(III) was studied and the results are reported in this paper. Superior extraction of the target metals and excellent separation factors achieved with the use of the ionic liquid diluent indicates the feasibility of separating lanthanides from actinides present in high-level liquid waste (HLLW). (C) 2011 Elsevier B.V. All rights reserved.