Separation and Recovery of Eu(III) and Y(III) with Solvent Impregnated Resin Coated by Crosslinked Chitosan

抄録

Separation of europium (Eu³⁺) and yttrium (Y³⁺), using a solvent impregnated resin (SIR) containing 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester, coated by water-soluble chitosan crosslinked by glutaraldehyde, was investigated. Coating of the SIR successfully suppressed leakage of the extractant during adsorption processing. Adsorption of Eu³⁺ with both coated and uncoated SIRs was progressed with Langmuir mechanism, and the maximum adsorption amount of Eu³⁺ at equilibrium pH = 2.27 was 0.294 mol/kg with coated SIR and 0.310 mol/kg with uncoated SIR. Decrease in the maximum adsorption amount by coating SIR with polymer can be suppressed rather than the other coated SIRs previously reported. The coated SIR was then applied to column separation of Eu³⁺ and Y³⁺. Complete separation of the metals could be achieved by gradient elution with a gradual increase in the concentration of a dilute nitric acid. The coated SIR could also be reused for repeated adsorption-elution processing.