Singlet oxygen-dominated peroxymonosulfate activation by layered crednerite for organic pollutants degradation in...

Advanced oxidation processes have been widely studied for organic pollutants treatment in water, but the degradation performance of radical-dominated pathway was severely inhibited by the side reactions between the anions and radicals, especially in high salinity conditions. Here, a singlet oxygen (¹O₂)-dominated non-radical process was developed for organic pollutants degradation in high salinity wastewater, with layered crednerite (CuMnO₂) as catalysts and peroxymonosulfate (PMS) as oxidant. Based on the experiments and density functional theory calculations, ¹O₂ was the dominating reactive species and the constructed Cu-O-Mn with electron-deficient Mn captured electron from PMS promoting the generation of ¹O₂. The rapid degradation of bisphenol A (BPA) was achieved by CuMnO₂/PMS system, which was 5-fold and 21-fold higher than that in Mn₂O₃/PMS system and Cu₂O/PMS system. The CuMnO₂/PMS system shown prominent BPA removal performance under high salinity conditions, prominent PMS utilization efficiency, outstanding total organic carbon removal rate, wide range of applicable pH and good stability. This work unveiled that the ¹O₂-dominated non-radical process of CuMnO₂/PMS system overcame the inhibitory effect of anions in high salinity conditions, which provided a promising technique to remove organic pollutants from high saline wastewater.