Solvent Extraction of Th(IV) and Eu(III) Ions by 3,5-di-tert-butyl-2-Hydroxy-Benzaldehyde Oxime from Aqueous Chloride Media

Abstract

The extractive properties of an oxime derivative, named 3,5-di- tert -butyl-2-hydroxy-benzaldehyde oxime dissolved in dichloromethane, have been investigated towards thorium(IV) and europium(III) ions from chloride media at 298 K. The analysis of the extraction data reveals that the thorium and europium ions are extracted as the complexes with metal/ligand ratios of 1:3 and 1:1, respectively. The examined extractant presents superior extractive properties towards thorium than europium ions. The influence of temperature on the extraction process of the studied ions was assessed in the range 288-303 K. The distribution ratios of both metal ions decreased with temperature. Thermodynamic parameters energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) changes associated with the extraction processes were evaluated.

Keywords:

• europium
• oxime
• solvent extraction
• thermodynamics
• thorium

Notes

^a Experimental conditions: Initial metal ion concentration (1 × 10⁻⁴ M); initial ligand concentration (0.001 M); temperature, 298 K.

^a Mean value of three independent extraction experiments.

^a Calculating using the least-squares method.