Selective Separation of Lanthanides with Phenolic Resins: Extraction Behavior and Thermal Stability

Abstract

Catechol, resorcinol, and their admixtures with 8-hydroxyquinoline were converted into polymeric resins by alkaline polycondensation with formaldehyde. The resins were characterized by FTIR spectroscopy, moisture regain, ion-exchange capacity, and distribution coefficient (D) for Eu³⁺. Thermogravimetric analysis of the polymer samples was studied, and the effect of the sorption of metal ions on their thermal stability was evaluated. Complexation of Eu³⁺ to the resins was modeled based on metal ion charge neutralization. The selective uptake of Eu³⁺ from aqueous solutions containing La³⁺ was investigated, and the ionoselectivities of the resins were compared. The incorporation of 8-hydroxyquinoline in the molecular matrix of the phenolic resins is shown to exert a significant influence upon the competitive sorption of La³⁺ and Eu³⁺, leading to their intragroup separation. The separation factors obtained by phenolic ion-exchange resins from aqueous solutions indicate ion-specific resins can be developed for the specific separation of actinide ions from nuclear waste.

ACKNOWLEDGMENTS

The authors thank Pr. B. Chabert (Laboratory of Plastic materials and Biomaterials study, Lyon University) for providing the TG facility, and Drs. N. Zydowicz and O. Gain for helping with TG experiments.