Enhanced peroxone reaction with amphoteric oxide modulation for efficient decontamination of challenging wastewaters: Comparative performance, economic evaluation, and pilot-scale implementation.

The peroxone reaction, a promising alternative technology for water treatment, is traditionally hampered by its restricted pH operational range and suboptimal oxidant utilization. In this study, we introduced a novel amphoteric metal oxide (ZnO)-regulated peroxone system that transcended the pH limitations of conventional peroxone processes. Our innovative approach exploited the unique properties of ZnO to regulate the reaction pathway of the traditional O/HO (or peroxymonosulfate, PMS) processes, resulting in a 52.4 % (64.9 %) increase in the removal efficiency of electron-deficient pollutant atrazine under acidic conditions (pH=5.8). This was achieved through the facilitated generation of hydroxyl radicals (OH) and sulfate radicals (SO), alongside a marked increase in the utilization efficiency of O, thus reducing the requisite amount of oxidant. The primary active sites within this system were identified as zinc-oxidant sites, with the critical interfacial interactions between ZnO and oxidants elucidated through comprehensive analytical techniques. These studies reveal that ZnO acted as an electron acceptor, with HO (or PMS) serving as the electron donor, leading to the formation of a reactive intermediate. This intermediate subsequently engaged with O, producing secondary radicals such as HO (SO) and O, which were instrumental in generating the final radical species, OH and SO. The efficacy of this ZnO-regulated peroxone process was validated through resistance to interference tests, treatment of pilot-scale coking wastewater (mineralization rate of over 70 %), and extensive biological toxicity evaluations, all of which validated the system's robust degradation capability, stability, and significant detoxification potential. A detailed comparison of reaction systems with conventional technologies using Electrical Energy per Order (EE/O) and Life Cycle Assessment (LCA) further highlighted the advantages. This investigation offers a groundbreaking solution for the treatment of complex wastewater, showcasing the substantial promise of ZnO-catalyzed peroxone for practical wastewater treatment applications.