Degradation of the mixed nuclear-grade cationic and anionic exchange resins using Fe2+/H+ homogeneous Fenton oxidation.

Xiang Meng, Jianlong Wang, Lejin Xu

Environmental research 2022 Sep

filter terms:

To further improve the treatment capacity of actual wastes, H+ was introduced into the homogeneous Fenton system as a co-catalyst for dissolution and degradation of the mixed nuclear-grade cationic and anionic exchange resins. The effects of acid type and concentration, catalyst type and concentration, H2O2 dosage, initial temperature, antifoaming agent and resin ratio were studied. The concentration of inorganic acid, type and concentration of catalyst had significant influence on the decomposition of mixed resins. The experimental results showed that when the mixing ratio of resins was 1:1, the initial temperature was 96 ± 1 °C, the amount of H2O2 was 200 mL, and the concentration of H+/Fe2+ was 1 M/0.1 M, complete dissolution and 79% weight reduction of mixed resins were obtained. Combined with density functional theory (DFT) calculations, cationic exchange resin and anionic exchange resin showed different reactivity in the experiment. Hydroxyl radicals (•OH) tended to attack -SO3- groups with more negative charges, and the barrier energy of -SO3- ion dissociation was 8.2 kcal/mol, which caused the cationic exchange resin to be easily destroyed. According to the characterization results, the characteristic intermediates were determined, indicating that desulfonation, valence change of nitrogen atom, and cleavage of long-chain carbon skeleton existed during the reaction, but incomplete oxidation still remained. Copyright © 2022 Elsevier Inc. All rights reserved.

Citation

Xiang Meng, Jianlong Wang, Lejin Xu. Degradation of the mixed nuclear-grade cationic and anionic exchange resins using Fe2+/H+ homogeneous Fenton oxidation. Environmental research. 2022 Sep;212(Pt C):113400