Chemically Modified Chloromethylated Resin as an Effective Metal Chelator in the Extraction of U(VI) and Th(IV)

Abstract

A novel chelating polymer has been developed using Merrifield Chloromethylated resin modified with Thenoyl trifluoroacetone (TTA), for the selective extraction of U(VI) and Th(IV). Characterization of the modified polymeric matrix was performed by FT-IR Spectrometer, CHNPS Elemental Analyzer. The synthesized resin showed superior ion-selective behavior even in the presence of high concentration of alkali, alkaline earth, and transition metal ions. Various physio-chemical parameters influencing the metal sorption on to the polymeric matrix was investigated and optimized by both batch and column method. Quantitative extraction of metal ions was effective in the pH range 4–5 and 2–4 for U(VI) and Th(IV) respectively. The system showed faster exchange kinetics for metal ion extraction, with complete saturation in <20 min. Maximum metal sorption capacity by the resin matrix, for U(VI) and Th(IV) was found to be 138.6 µmol g⁻¹ and 117.2 µmol g⁻¹ respectively. Sample break through volume and flow rate studies were performed by column method. Ion-selectivity behavior and preconcentrating ability was tested, using synthetic and real water samples. The system showed consistent trace recovery with an rsd value of ≤4.3% for all analytical data.

Keywords:

• Extraction
• U(VI)
• Th(VI)
• Chloromethylated resin
• Metal chelates