Selective Extraction of Actinides Using EEBEHBA Grafted Polymer: A Green Process for Nuclear Reprocessing Program

Abstract

A new amide grafted polymer has been developed using Merrifield chloromethylated resin (inert solid support) anchored with 4‐ethoxy‐4‐ethyl‐N,N‐bis‐2‐ethylhexylbutanamide (EEBEHBA), for the selective extraction of actinides from lanthanides in acidic matrices. The polymer has been characterized using ¹³C‐ CPMAS (cross‐polarized magic angle spin) NMR spectroscopy, FT‐NIR spectroscopy, and also by CHN elemental analysis. The fabricated polymeric sorbent shows greater selectivity in extracting U(VI) over Th(IV) and other lanthanides, even under high acidities (2–4 M HNO₃). The grafted polymer offers good distribution ratio (D) values for actinides of interest over a wide range of solution acidity, with the maximum metal sorption capacity being 0.629 mmol g⁻¹ and 0.214 mmol g⁻¹ for U(VI) and Th(IV), respectively, in 4 M HNO₃ medium. The functionalized resin matrix shows moderately fast metal ion phase exchange kinetics, with t_1/2 values < 3 min for both the analytes. The notable feature of the resin is the quantitative desorption of actinides using distilled water as eluant, a simple green process of recovery which has not yet been reported in the literature using polymeric sorbents. The practical utility has been tested using synthetic low‐level nuclear reprocessing mixtures and also with real samples like monazite sand. The analytical data obtained from triplicate measurements are within 3.6% rsd reflecting the reproducibility and reliability of the developed method.

Keywords:

• Actinides
• Amide grafted polymer
• Preconcentration
• Acidic matrices