Amine/Carboxylic Acid Based Bifunctional Ionic Liquids as Extractants for Nd(III), Sm(III) and Eu(III) from Aqueous Solution Containing EDTA

Abstract

AbstractTwo bi‐functional ionic liquid extractants (Bif‐ILs) comprising tertiary amine and carboxylic acids, namely [TOAH]+[OHex]− (Tri‐n‐octylaminehexanoate) and [TOAH]+[ODec]− (Tri‐n‐octylaminedecanoate) in kerosene have been used for extraction of Nd(III), Sm(III) and Eu(III) from aqueous phase with EDTA as a complexing agent. The extraction ability of both the extracting agents has been analyzed with respect to variations in shaking time, concentration of extractant, aqueous phase pH, molarity of EDTA, diluents and phase volume ratio. Using 0.08 mol/L EDTA,extraction of Nd(III) was maximum with both the extractants followed by Sm(III) and Eu(III).At 4 : 1 (O/A) phase volume ratio, the extraction percentages using [TOAH]+[OHex]− were 93.42 % (Nd), 89.83 % (Sm), 84.14 % (Eu) and with [TOAH]+[ODec]− the values were 90.42 % (Nd), 89.37 % (Sm), 83.65 % (Eu), respectively.Extraction efficiency of both Bif‐ILs is maximum for Nd(III). Stripping was quantitative with HNO3 and HCl.Speciation studies and FTIR spectra provide valuable information regarding the stoichiometry of the extracted species.