Enhanced degradation of cyclic ketone and its diamine derivative using ozone/peroxymonosulfate (O₃/PMS) process

Cyclic ketones and their diamine derivatives are industrially important but challenging to degrade via ozonation ( O 3 ) due to their electron-deficient double bonds. This study presents the first comprehensive evaluation of O 3 and a combined O 3 -peroxymonosulfate ( O 3 / PMS ) process for degrading cyclic ketones through direct O 3 oxidation and indirect reactions involving hydroxyl ( HO • ) and sulfate ( SO 4 • − ) radicals. Isophorone (IP) and isophorone diamine (IPD) were selected as representative electron-deficient compounds. The second-order rate constants for reactions with HO • and SO 4 • − ranged from 10 8 to 10 9 M − 1 s − 1 over pH 3–9, depending on the radical species. While O 3 alone resulted in limited degradation, the combined O 3 / PMS process significantly improved the removal efficiency under neutral conditions. Higher pH values accelerated O 3 decomposition and enhanced radical generation. Semi-batch experiments using industrial wastewater with continuous O 3 flow under O 3 / PMS process achieved mineralization efficiencies of 50–60 %. These findings highlight the potential of O 3 and O 3 / PMS processes for treating electron-deficient organic compounds via radical-mediated pathways and support their scalability for highly loaded DOC wastewaters, pending pilot-scale validation. • First kinetic quantification of IP/IPD with O 3 / PMS under competitive conditions • HO • and SO 4 • − are the primary species driving IP and IPD removal by O 3 / PMS . • O 3 / PMS process achieved 89 % degradation efficiency at neutral pH. • Up to 60 % TOC removal in real wastewater, showing practical applicability