Remediation and mineralization processes for per- and polyfluoroalkyl substances (PFAS) in water: A review

Per- and polyfluoroalkyl substances (PFAS) are synthetic organic molecules used to manufacture various consumer and industrials products. In PFAS, the C\\F bond is stable, which renders these compounds chemically stable and prevents their breakdown. Several PFAS treatment processes such as adsorption, photolysis and photocatalysis, bioremediation, sonolysis, electrochemical oxidation, etc., have been explored and are being developed. The present review article has critically summarized degradative technologies and provides in-depth knowledge of photodegradation, electrochemical degradation, chemical oxidation, and reduction mineralization mechanism. Also, novel non-degradative technologies, including nano-adsorbents, natural and surface-modified clay minerals/zeolites, calixarene-based polymers, and molecularly imprinted polymers and adsorbents derived from biomaterials are discussed in detail. Of these novel approaches photocatalysis combined with membrane filtration or electrochemical oxidation via a treatment train approach shows promising results in removing PFAS in natural waters. The photocatalytic mineralization mechanism of PFOA is discussed, leading to recommendations for future research on novel remediation strategies for removing PFAS from water. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

Per- and polyfluoroalkyl substances (PFAS) are synthetic organic molecules used in various consumer and industrial products, known for their chemical stability due to the stable C\\F bond. Different treatment processes for PFAS degradation have been explored, including adsorption, photolysis, bioremediation, etc. Novel non-degradative technologies like nano-adsorbents and photocatalysis combined with membrane filtration have shown promising results in removing PFAS from natural waters.