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 –, IO 3 – ) is of great importance in radioactive waste management. Here, a Cu 2 O-loaded three-dimensional bulk cationic hydrogel composite (Cu 2 O@CH) was successfully prepared by simple redox reactions and UV photopolymerization, which realized the rapid enrichment and efficient immobilization of I – and IO 3 – . The adsorption experiments showed that the maximum adsorption capacity of Cu 2 O@CH for I – in the solution at pH = 3 reached 416.5 mg/g, and the adsorption capacity of IO 3 – in the solution at pH = 6 could reach 313.4 mg/g. It exhibited extremely fast adsorption kinetics for I – and IO 3 – . In addition, Cu 2 O@CH also exhibited efficient I – and IO 3 – removal from simulated high-level liquid waste. The rapid capture and effective immobilization of radioiodine (I –, IO 3 – ) were realized by the electrostatic interaction of −N + (CH 3 ) 3 groups in Cu 2 O@CH with I – and IO 3 –, as well as the chemical reactions between Cu 2 O 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 3 – ) in nuclear wastewater treatment.