Synergistic mechanism and degradation kinetics for atenolol elimination via integrated UV/ozone/peroxymonosulfate process

Abstract

The present research systematically investigates the atenolol (ATL) degradation in integrated UV/Ozone (O3)/peroxymonosulfate (PMS) process focusing on the synergistic mechanism, reaction kinetics, pollutant degradation pathway and antibacterial activity. The results manifested that the integrated UV/O3/PMS process showed the noteworthy superiority to ATL degradation compared with UV/PMS, UV/O3 and O3/PMS systems. Simultaneously, the impacts of operating parameters like PMS dosage, initial ATL concentration, solution pH and water matrix were comprehensively explored. The ATL elimination efficiency increased linearly with PMS dose and significantly enhanced in alkaline conditions. The •OH and SO4•− were the primary reactive radicals for ATL oxidation in UV/O3/PMS system based on the radical scavenging experiments and electron paramagnetic resonance characterization. Besides, a simplified kinetic model on the basis of the dominant reactions and the steady-state assumption was established to foretell the relative contributions of reactive oxidants for ATL elimination in UV/O3/PMS process. Main transformation products were determined via UPLC-QTOF-MS to infer the possible degradation pathways of ATL. Furthermore, the UV/O3/PMS process could distinctly mitigate the antibacterial activity of ATL and its intermediates to E. coli and B. subtilis. Our findings may have critical implications for the development of novel oxidation processes for recalcitrant contaminants mitigation in water purification.