Three pyridine-based aqueous complexants have been synthesized and used in an unbuffered TALSPEAK (Trivalent Actinide Lanthanide Separation by Phosphorus-reagent from Aqueous Komplexes) separation system as minor actinide-selective holdback reagents. The selectivity was established based on distribution studies using radiotracer 152/154Eu, 241Am, stable Ln, Y and Th. In this system, these ligands selectively sequester Am from the lanthanides without the need for a secondary pH buffer. Am-lanthanide separation factors for Eu were found to be > 70 for all three ligands and > 15 for Nd. Aqueous pyridine based ligands represent viable alternatives for traditional actinide-selective holdback reagents in TALSPEAK-based systems.
Revised: January 14, 2021 |
Published: June 6, 2020
Citation
Uhnak N.E., and K. Nash. 2020.Pyridine Polyaminocarboxylate Ligands for Use as Actinide-selective Holdback Reagents in Simplified TALSPEAK-like Extraction Systems.Solvent Extraction and Ion Exchange 38, no. 4:401-416.PNNL-SA-147107.doi:10.1080/07366299.2020.1741124