The Degradation of Polycyclic Aromatic Hydrocarbons (PAHs) by Ozone-Based Advanced Oxidation Processes: A Review

ABSTRACTABSTRACTAs a set of persistent organic pollutants (POPs) that cause serious harm to human and animal health, polycyclic aromatic hydrocarbons (PAHs) degradation has attracted attentions of many scholars. Ozonation is one of the promising techniques for removing PAHs from various aqueous solutions because of its molecular structures, rapid reaction with ozone (O3), and oxidation by-products of PAHs produced during ozonation are more biodegradable than initial PAHs. However, its application is constrained by the high cost of ozone production, and organic matter in water is only partially oxidized. In recent years, to improve the efficiency of the ozonation process and optimize economic efficiency, several methods of O3-based advanced oxidation processes (AOPs) (i.e. O3/UV, O3/H2O2, O3/H2O2/UV, O3/Fenton, O3/Catalyst) have been studied. These AOPs generate more HO• than molecular ozone. This review summarized recent developments relating to the degradation of PAHs via O3-based AOPs and their exciting mechanisms. Compared different processes characteristics in terms, such as radical species, operational conditions, by-products and their toxicity, and cost. We considered that O3/photocatalyst seems to be a better choice for PAHs degradation. Finally, the challenges and future trends of PAH degradation have prospected.KEYWORDS: Advanced oxidation processesHydroxyl radicalsOzonationpollution treatmentpolycyclic aromatic hydrocarbons AcknowledgmentsThe authors gratefully acknowledge the financial support from Shanghai Pujiang Program (20PJ1404800). We thank all reviewers and editors for reviewing the manuscript and providing valuable comments.Disclosure statementNo potential conflict of interest was reported by the authors.Data availability statementNo data, models, or code were generated or used during the study.