TY - GEN A1 - Ahmed, Naveed A1 - Martienssen, Marion A1 - Bryant, Isaac Mbir A1 - Vione, Davide A1 - Bruzzoniti, Maria Concetta A1 - Riedel, Ramona T1 - Investigation on UV Degradation and Mechanism of 6:2 Fluorotelomer Sulfonamide Alkyl Betaine, Based on Model Compound Perfluorooctanoic Acid T2 - ChemEngineering N2 - The UV treatment of 6:2 FTAB involves the mitigation of this persistent chemical by the impact of ultraviolet radiation, which is known for its resistance to environmental breakdown. UV treatment of PFOA and/or 6:2 FTAB, and the role of responsible species and their mechanism have been presented. Our investigation focused on the degradation of perfluorooctanoic acid (PFOA) and 6:2 fluorotelomer sulfonamide alkyl betaine (6:2 FTAB, Capstone B), using UV photolysis under various pH conditions. Initially, we used PFOA as a reference, finding a 90% decomposition after 360 min at the original (unadjusted) pH 5.6, with a decomposition rate constant of (1.08 ± 0.30) × 10−4 sec−1 and a half-life of 107 ± 2 min. At pH 4 and 7, degradation averaged 85% and 80%, respectively, while at pH 10, it reduced to 57%. For 6:2 FTAB at its natural pH 6.5, almost complete decomposition occurred. The primary UV transformation product was identified as 6:2 fluorotelomer sulfonic acid (6:2 FTSA), occasionally accompanied by shorter-chain perfluoroalkyl acids (PFAAs) including PFHpA, PFHxA, and PFPeA. Interestingly, the overall decomposition percentages were unaffected by pH for 6:2 FTAB, though pH influenced rate constants and half-lives. In PFOA degradation, direct photolysis and reaction with hydrated electrons were presumed mechanisms, excluding the involvement of hydroxyl radicals. The role of superoxide radicals remains uncertain. For 6:2 FTAB, both direct and indirect photolysis were observed, with potential involvement of hydroxyl, superoxide radicals, and/or other reactive oxygen species (ROS). Clarification is needed regarding the role of 𝑒−𝑎𝑞 in the degradation of 6:2 FTAB. KW - PFOA KW - 6:2 FTAB KW - decomposition KW - photolysis KW - scavenger Y1 - 2024 U6 - https://doi.org/10.3390/chemengineering8020032 SN - 2305-7084 VL - 8 IS - 2 ER - TY - GEN A1 - Ahmed, Naveed A1 - Martienssen, Marion A1 - Bryant, Isaac Mbir A1 - Vione, Davide A1 - Bruzzoniti, Maria Concetta A1 - Riedel, Ramona T1 - Investigation on UV Degradation and Mechanism of 6:2 Fluorotelomer Sulfonamide Alkyl Betaine, Based on Model Compound Perfluorooctanoic Acid T2 - ChemEngineering Y1 - 2024 U6 - https://doi.org/10.3390/chemengineering8020032 SN - 2305-7084 VL - 8 IS - 2 ER -