Cuprous Oxide-Based Cationic Hydrogel by the Integration of Enrichment and Immobilization of Radioiodine (I–, IO3–) in Aqueous Solution

The efficient capture and immobilization of radioiodine (I–, IO3–) is of great importance in radioactive waste management. Here, a Cu2O-loaded three-dimensional bulk cationic hydrogel composite (Cu2O@CH) was successfully prepared by simple redox reactions and UV photopolymerization, which realized the rapid enrichment and efficient immobilization of I– and IO3–. The adsorption experiments showed that the maximum adsorption capacity of Cu2O@CH for I– in the solution at pH = 3 reached 416.5 mg/g, and the adsorption capacity of IO3– in the solution at pH = 6 could reach 313.4 mg/g. It exhibited extremely fast adsorption kinetics for I– and IO3–. In addition, Cu2O@CH also exhibited efficient I– and IO3– removal from simulated high-level liquid waste. The rapid capture and effective immobilization of radioiodine (I–, IO3–) were realized by the electrostatic interaction of −N+(CH3)3 groups in Cu2O@CH with I– and IO3–, as well as the chemical reactions between Cu2O 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–, IO3–) in nuclear wastewater treatment.