Advanced Oxidation Processes in Environmental Chemistry

Advanced Oxidation Processes (AOPs) are a class of treatment technologies that generate highly reactive species (primarily hydroxyl radicals, •OH, and sulfate radicals, SO4•–) to oxidize and mineralize a wide range of organic contaminants in water and wastewater. This review covers the fundamental chemistry, main AOP variants including Fenton, photo-Fenton, photocatalysis, ozonation, persulfate-based systems, and electrochemical AOPs, discusses reactor design and kinetics, highlights analytical considerations and monitoring, and presents recent case studies (2020–2025) illustrating successes and practical challenges. Key research needs and scale-up barriers are also identified. [1,17]