Functionality screening to help design effective materials for radioiodine abatement.

Area of Science:

• Environmental Science
• Materials Science
• Nuclear Chemistry

Background:

• Nuclear fuel reprocessing generates aqueous waste containing radioiodine.
• Effective containment of radioiodine is crucial for environmental safety and regulatory compliance.
• Developing efficient adsorbents is key to radioiodine abatement strategies.

Purpose of the Study:

• To screen and identify optimal metalated adsorbents for capturing aqueous radioiodine.
• To evaluate the iodide uptake capacity of commercial ion exchange resins under various conditions.
• To understand the influence of operational parameters on adsorbent performance for industrial application.

Main Methods:

• A two-tier screening process was employed for 32 metalated commercial ion exchange resins.
• Initial screening assessed iodide capacity, with candidates >40 mg·g⁻¹ progressing.
• Fractional factorial design evaluated adsorbents under extreme conditions (iodide, co-contaminants, pH).

Main Results:

• All resins showed significant iodide capacity (12-220 mg·g⁻¹).
• Iodide concentration, nitrate concentration, and pH significantly influenced uptake.
• Silver-loaded Purolite S914 (thiourea functionality) demonstrated the highest performance, despite some salt precipitation.

Conclusions:

• Metalated thiourea, bispicolylamine, and aminomethylphosphonic acid functionalized silicas are promising for radioiodine capture.
• Optimized adsorbent selection can enhance radioiodine abatement efficiency in nuclear waste management.
• Further research into these functionalized materials is recommended for industrial implementation.