Per- and polyfluoroalkyl substances (PFAS) degradation and defluorination involving ultraviolet and ultrasonication activated advanced oxidation and reduction

Abstract

Per- and polyfluoroalkyl substances (PFAS) are an extremely persistent and ubiquitous class of anthropogenic chemicals, used globally in a wide range of industrial and commercial applications. They are toxic to humans and wildlife, and recalcitrant to most of the conventional water treatment methods. PFAS pose a serious challenge to water treatment, considering they are widespread in the environment and difficult to breakdown because of their unique physical and chemical properties, including strong C-F bond structure, hence they are called ‘forever chemicals’. Breaking down PFAS into their starting elements, or even naturally degradable products, is extremely difficult with most treatment techniques, thus developing an efficient and cost-effective treatment methodology would be an important breakthrough. The objective of this research was to adapt currently available water treatment techniques for micropollutants for improving PFAS breakdown efficiency. We used low frequency ultrasonication (US) in the presence of oxidative and/or reducing agents, and with or without catalysts, to enhance PFAS degradation.