Per- and polyfluoroalkyl substances (PFASs) are a class of artificial compounds comprised of a perfluoroalkyl main chain and a terminal functional group. With them being applied in a wide range of applications, PFASs have drawn increasing regulatory attention and research interests on their reductions and treatments due to their harmful effects on environment and human beings. Among numerous studies, chemical treatments (e.g., photochemical, electrochemical, and thermal technologies) have been proved to be important methods to degradation PFASs. However, the pathways and mechanisms for the degradation of PFASs through these chemical methods still have not been well documented. This article therefore provides a comprehensive review on the degradation mechanisms of two important PFASs (perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)) with photochemical, electrochemical and thermal methods. Different decomposition mechanisms of PFOA and PFOS are reviewed and discussed. Overall, the degradation pathways of PFASs are associated closely with their head groups and chain lengths, and H/F exchange and chain shortening were found to be predominant degradation mechanisms. The clear study on the degradation mechanisms of PFOA and PFOS should be very useful for the complete degradation or mineralization of PFASs in the future.

全氟和多氟烷基物质 (PFAS) 是一类由全氟烷基主链和末端官能团组成的人工化合物。随着它们的广泛应用，PFAS 因其对环境和人类的有害影响而引起越来越多的监管关注和对其减少和处理的研究兴趣。在众多研究中，化学处理（例如光化学、电化学和热技术）已被证明是降解 PFAS 的重要方法。然而，通过这些化学方法降解全氟和多氟烷基物质的途径和机制仍未得到很好的记录。因此，本文通过光化学、电化学和热方法对两种重要的 PFAS（全氟辛酸 (PFOA) 和全氟辛烷磺酸 (PFOS)）的降解机制进行了全面综述。审查和讨论了 PFOA 和 PFOS 的不同分解机制。总体而言，PFAS 的降解途径与其头部基团和链长密切相关，并且发现 H/F 交换和链缩短是主要的降解机制。对PFOA和PFOS降解机制的明确研究，对于未来PFASs的完全降解或矿化将非常有用。PFAS 的降解途径与其头基和链长密切相关，发现 H/F 交换和链缩短是主要的降解机制。对PFOA和PFOS降解机制的明确研究，对于未来PFASs的完全降解或矿化将非常有用。PFAS 的降解途径与其头基和链长密切相关，发现 H/F 交换和链缩短是主要的降解机制。对PFOA和PFOS降解机制的明确研究，对于未来PFASs的完全降解或矿化将非常有用。