| Autor: |
Yi S; Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States., Harding-Marjanovic KC; Exponent, Pasadena, California 91106, United States., Houtz EF; Arcadis, San Francisco, California 94104, United States., Gao Y; Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China., Lawrence JE; Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States., Nichiporuk RV; The California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California 94720, United States., Iavarone AT; The California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California 94720, United States., Zhuang WQ; Department of Civil and Environmental Engineering, University of Auckland, Auckland 1142, New Zealand., Hansen M; Department of Environmental Science, Aarhus University, 4000 Roskilde, Denmark., Field JA; Department of Molecular and Environmental Toxicology, Oregon State University, Corvallis, Oregon 97331, United States., Sedlak DL; Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States., Alvarez-Cohen L; Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States.; Earth and Environmental Sciences Division, Lawrence Berkeley National Laboratory, Cyclotron Road, Berkeley, California 94720, United States. |
| Abstrakt: |
The fate of per and polyfluoroalkyl substances (PFASs) in aqueous filmforming foams (AFFFs) under anaerobic conditions has not been well characterized, leaving major gaps in our understanding of PFAS fate and transformation at contaminated sites. In this study, the biotransformation of 6:2 fluorotelomer thioether amido sulfonate (6:2 FtTAoS), a component of several AFFF formulations, was investigated under sulfate-reducing conditions in microcosms inoculated with either pristine or AFFF-impacted solids. To identify the transformation products, we used high-resolution mass spectrometry and employed suspect-screening and nontargeted compound identification methods. These analyses demonstrated that 6:2 FtTAoS was transformed primarily to a stable polyfluoroalkyl compound, 6:2 fluorotelomer thioether propionate (6:2 FtTP). It did not undergo further reactions to produce the perfluoroalkyl carboxylates and fluorotelomer sulfonates and carboxylates that were observed during aerobic transformations. Here, the 6:2 FtTP was recalcitrant to biotransformation, indicating the stability of the thioether group under sulfate reducing conditions. The total oxidizable precursor (TOP) assay was used to assess the presence of other PFASs. Although nearly all of the PFAS mass initially present was recovered from the pristine microcosms, only 67% of the initial PFAS mass was recovered from the contaminated microcosms, suggesting the formation of volatile biotransformation products or those that could not be detected by the TOP assay. |
