Cuprous Oxide-Based Cationic Hydrogel by the Integration of Enrichment and Immobilization of Radioiodine (I, IO) in Aqueous Solution.

The efficient capture and immobilization of radioiodine (I, IO) is of great importance in radioactive waste management. Here, a CuO-loaded three-dimensional bulk cationic hydrogel composite (CuO@CH) was successfully prepared by simple redox reactions and UV photopolymerization, which realized the rapid enrichment and efficient immobilization of I and IO. The adsorption experiments showed that the maximum adsorption capacity of CuO@CH for I in the solution at pH = 3 reached 416.5 mg/g, and the adsorption capacity of IO in the solution at pH = 6 could reach 313.4 mg/g. It exhibited extremely fast adsorption kinetics for I and IO. In addition, CuO@CH also exhibited efficient I and IO removal from simulated high-level liquid waste. The rapid capture and effective immobilization of radioiodine (I, IO) were realized by the electrostatic interaction of -N(CH) groups in CuO@CH with I and IO, as well as the chemical reactions between CuO and I. The bulk cationic hydrogel composite explored the multifunctional role toward fast, high adsorption capability and easy handling, highlighting its superiority compared to the powder adsorbent, which renders it a potential adsorbent for the removal of radioactive iodine (I, IO) in nuclear wastewater treatment.