Abstract: In this presentation, Prof. Dionysiou will provide an overview of his work during the last several years on the development, mechanisms involved, and performance evaluation of advanced oxidation technologies based on sulfate radical (SO^−•₄) for water treatment. The discussion will include information on such technologies, mechanism of activation to generate SO^−•₄ using various methods, basic mechanisms of action of SO^−•₄, kinetics and mechanisms of degradation of various types of organic contaminants by SO^−•₄, role of process conditions and water quality parameters, and application case studies in engineered systems. Discussion will include activation methods to generate SO^−•₄ from persulfate and peroxymonosulfate using transition metals, electrochemical methods, alkaline conditions, carbonaceous materials, other oxidants, sonolysis, radiation, and various combination of these and other methods. Elucidation of degradation mechanisms will be discussed from both experimental and theoretical perspectives. Discussion of the degradation studies will be focused on a variety of persistent/emerging organic contaminants, such as phenolic compounds, pesticides (e.g., endosulfan, lindane, atrazine), cyanotoxins, pharmaceuticals and personal care product compounds, and perfluorinated chemicals. Prof. Dionysiou will emphasize and provide examples on the role and importance of the environmental matrix on degradation kinetics of organic contaminants. Examples of studies using surface water, groundwater, and industrial wastewater as matrices will be provided. While results in this presentation will be primarily from Dionysiou’s group and his collaborators, selected important topics will also be discussed from important work of other research groups.

Keywords: Advanced Oxidation Processes, Contaminants of Emerging Concern, Cyanotoxins, Sulfate Radicals, Water Treatment