Highly efficient Plutonium(IV) uptake from acidic feeds using four extraction chromatography resins containing...

Area of Science:

• Radiochemistry
• Separation Science
• Environmental Chemistry

Background:

• Quantitative recovery of plutonium from lean effluents presents significant challenges in separation science.
• Extraction chromatography (XC) offers a promising avenue for selective radionuclide separation.

Purpose of the Study:

• To investigate the efficiency of four XC resins with varying diglycolamide ligands for plutonium (IV) extraction from nitric acid solutions.
• To evaluate the kinetic and isotherm models governing plutonium uptake and assess column performance.

Main Methods:

• Testing of four XC resins (TPDGA, THDGA, TODGA, TDDGA) for Pu(IV) extraction across a range of nitric acid concentrations.
• Analysis of uptake data using pseudo-second order kinetic and Langmuir adsorption models.
• Conducting column studies to evaluate breakthrough and elution characteristics.

Main Results:

• Resin efficiency followed the order TPDGA > THDGA > TODGA > TDDGA, inversely related to alkyl chain length.
• Pu(IV) uptake decreased with increasing nitric acid concentration at lower acidities, then increased.
• All resins followed pseudo-second order kinetics and Langmuir adsorption, with shorter chain ligands showing better column performance.

Conclusions:

• Diglycolamide-based XC resins are effective for plutonium recovery from lean effluents.
• Ligand structure, specifically alkyl chain length, significantly impacts plutonium extraction efficiency.
• Optimized elution was achieved using oxalic acid in nitric acid, demonstrating practical applicability.