Highly Efficient Solvent Extraction of Americium and Europium by Using Hydrogen Dicarbollylcobaltate and N,N′-Diethyl-N,N′-bis(4-ethylphenyl)-1,10-phenanthroline-2,9-dicarboxamide

Abstract

Solvent extraction of microamounts of Eu3+ and Am3+ from water into nitrobenzene by means of a mixture of hydrogen dicarbollylcobaltate (H+B−) and N,N′-diethyl-N,N′-bis(4-ethylphenyl)-1,10-phenanthroline-2,9-dicarboxamide (L) was studied. The equilibrium data were explained assuming that the species HL+, $$ \text{HL}_{\text{2}}^{ + } $$ , $$ \text{ML}_{2}^{3 + } $$ , and $$ \text{ML}_{\text{3}}^{{\text{3} + }} $$ (M3+ = Eu3+, Am3+; L = N,N′-diethyl-N,N′-bis(4-ethylphenyl)-1,10-phenanthroline-2,9-dicarboxamide) are extracted into the organic phase. Extraction and stability constants of the cationic complex species in nitrobenzene saturated with water were determined and are discussed. The reached separation factors SFAm/Eu in this two-phase system are in the range of 19–99. From the experimental results it is apparent that this very effective N,N′-diethyl-N,N′-bis(4-ethylphenyl)-1,10-phenanthroline-2,9-dicarboxamide receptor for the Eu3+ and Am3+ cations could be considered as a potential extraction agent for nuclear waste treatment.