Degradation of per- and polyfluoroalkyl substances by peroxymonosulfate-based advanced oxidation processes: a review

초록

Pre- and polyfluoroalkyl substances (PFASs) are highly persistent anthropogenic pollutants. These compounds are extensively used for a wide range of industrial, consumer and commercial applications due to their resistance to heat, water and chemical degradation. However, their persistent nature has led to widespread contamination of water and soil as well as bioaccumulation in organisms. Since PFASs are chemically stable, toxic and bio-accumulative, they pose severe ecological and health risks to human beings and other animals. Owing to the strength of the C-F bond in PFASs, conventional treatment technologies are largely ineffective for PFAS removal. Recently, peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) have emerged as effective strategies of the day for PFAS degradation. This is because PMS activation via photo(electro)catalysis and thermal treatment results in the formation of reactive oxygen species and sulfate radicals capable of cleaving C-F bonds. This review summarizes the classifications, properties and toxicological impacts of PFASs as well as critically analyzes various PMS activation mechanism and their efficiency in PFAS degradation. Advantages and limitations of each method are compared, highlighting challenges such as incomplete mineralization, toxicity of intermediates, and limited scalability. Future perspectives suggest that research should prioritize the development of multifunctional catalysts for selective PMS activation, integration with other AOPs with complementary treatment methods, and assessment of degradation pathways under realistic environmental conditions. By addressing these gaps, PMS-based AOPs could be advanced towards practical and sustainable applications for PFAS remediation, offering a promising route to mitigate one of today's most pressing environmental challenges.

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