PFAS remediation: Evaluating the infrared spectra of complex gaseous mixtures to determine the efficacy of thermal decomposition of PFAS

• Published in: Chemosphere (Oxford) 2024-08, Vol.362 (C), p.142631, Article 142631
• Main Authors: Hughey, Kendall D., Gallagher, Neal B., Zhao, Yuwei, Thakur, Nikita, Bradley, Ashley M., Koster van Groos, Paul G., Johnson, Timothy J.
• Format: Article
• Language: English
• Subjects: Infrared spectroscopy; MCR; Perfluoroalkyl substances; PFAS; PFOS; Thermal decomposition
• ISSN: 0045-6535; 1879-1298; 1879-1298
• DOI: 10.1016/j.chemosphere.2024.142631

Due to their widespread production and known environmental contamination, the need for the detection and remediation of per- and polyfluoroalkyl substances (PFAS) has grown quickly. While destructive thermal treatment of PFAS at low temperatures (e.g., 200–500 °C) is of interest due to lower energy and infrastructure requirements, the range of possible degradation products remains underexplored. To better understand the low temperature decomposition of PFAS species, we have coupled gas-phase infrared spectroscopy with a multivariate curve resolution (MCR) analysis and a database of high-resolution PFAS infrared reference spectra to characterize and quantify a complex mixture resulting from potassium perfluorooctanesulfonate (PFOS–K) decomposition. Beginning at 375 °C, nine prevalent decomposition products (namely smaller perfluorocarbon species) are identified and quantified. [Display omitted] •Low-T thermal decomposition of potassium perfluorooctanesulfonate investigated.•IR spectroscopy and MCR reveal gas-phase decomposition products.•Nine perfluorocarbon species identified as products of PFOS thermal decomposition. SYNOPSIS; We report a method to assess both the efficacy and gas-phase products of low temperature decomposition of PFAS chemicals from water or soil.