Efficiency and mechanism of intermittent reductive/oxidative defluorination of PFOS using UV light

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental pollutants known for their high toxicity, even at low parts per trillion (ppt). Remediation efforts focus on the capture and destruction of heavily regulated PFAS, such as perfluorooctane sulfonate (PFOS), a compound of particular concern due to its high potential for bioaccumulation, persistence in ecosystems, global distribution, and adverse health effects. Conventional methods have shown limited success in achieving complete defluorination, often leaving behind toxic by-products. This research employs an innovative circular redox process, alternating between reductive and oxidative phases under UV light, to enhance PFOS degradation and defluorination. By optimizing reaction conditions, including sulfite and hydrogen peroxide as redox agents, the study aims to elucidate the degradation pathways and mechanisms. The primary objective is to achieve near-complete defluorination, contributing to more effective and sustainable water purification technologies while mitigating environmental and health risks.