Pioneering NTA-Chelating Resin Methodology for Sequential Th(IV) Capture from Highly Acidic Media.

Area of Science:

• Nuclear Chemistry
• Materials Science
• Radiochemistry

Background:

• High-level radioactive liquid waste (HLW) presents challenges for thorium(IV) recovery due to trace concentrations in complex matrices.
• Selective separation of thorium is vital for nuclear waste management and potential resource recycling.

Purpose of the Study:

• To develop and characterize a novel solid-phase extraction resin for efficient thorium(IV) separation.
• To evaluate the resin's performance, selectivity, and stability under simulated HLW conditions.

Main Methods:

• Immobilization of nitrilotriacetamide (NTA amide (C8)) onto a styrene-divinylbenzene support.
• Characterization using SEM, BET, FT-IR, and XPS.
• Batch and dynamic column studies to assess uptake kinetics, capacity, selectivity, and stability.

Main Results:

• The resin exhibited rapid Th(IV) uptake kinetics and high capacities (32.0 mg/g at 0.01 M HNO3, 73.3 mg/g at 7 M HNO3).
• Demonstrated excellent selectivity against competing ions and maintained over 90% performance after exposure to harsh conditions (10 M HNO3, 800 kGy radiation, multiple cycles).
• Dynamic column tests showed a breakthrough volume of ~180 mL and a dynamic capacity of 12.8 mg/g.

Conclusions:

• The developed resin is highly effective for selective Th(IV) separation from HLW.
• Its robustness, high capacity, and selectivity offer a promising solution for reducing radiotoxicity and enabling resource recycling in nuclear waste management.