Dong Sheng, Yan Peng-Fei, Manz Katherine E, Abriola Linda M, Pennell Kurt D, Cápiro Natalie L
Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, United States.
School of Public Health, University of Michigan, Ann Arbor, Michigan 48109, United States.
Environ Sci Technol. 2024 Dec 24;58(51):22777-22789. doi: 10.1021/acs.est.4c08665. Epub 2024 Dec 10.
The environmental fate of per- and polyfluoroalkyl substances (PFAS) in aqueous film-forming foams (AFFFs), especially those synthesized by electrochemical fluorination (ECF) processes, remains largely unknown. This study evaluated the transformation of AFFF-derived ECF-based precursors in aerobic soil microcosms amended with a historically used AFFF formulation (3M Light Water). Fifteen classes of PFAS, including AFFF components and transformation products, were identified or tentatively identified by suspect screening/nontargeted analysis (SSA/NTA) throughout a 308-day incubation. This study demonstrates that AFFF-derived ECF-based precursors serve as sources of perfluoroalkane sulfonamides (FASAs) and perfluoroalkyl acids (PFAAs), which are commonly detected at AFFF-impacted sites. Temporal sampling provided evidence for biotransformation of multiple precursors including tri- or dimethyl ammonio propyl perfluoroalkane sulfonamides. Additionally, the environmental stability (i.e., resistance to transformation) of ECF-based precursors was found to depend upon structural characteristics, including perfluoroalkyl chain length, presence of sulfonamide or carboxamide groups, and functional groups (e.g., a branch of carboxyalkyl group) attached to the nitrogen atoms. These findings provide insights into the transformation pathways of AFFF-derived PFAS and other structurally similar ECF-based PFAS, which will support the management and remediation of PFAS contamination at legacy AFFF-impacted sites.
水成膜泡沫（AFFF）中全氟和多氟烷基物质（PFAS）的环境归宿，尤其是那些通过电化学氟化（ECF）工艺合成的物质，在很大程度上仍然未知。本研究评估了在添加了历史上使用过的AFFF配方（3M轻水）的好氧土壤微观环境中，源自AFFF的基于ECF的前体的转化情况。在为期308天的培养过程中，通过可疑物筛查/非靶向分析（SSA/NTA）鉴定或初步鉴定了15类PFAS，包括AFFF成分和转化产物。本研究表明，源自AFFF的基于ECF的前体是全氟烷磺酰胺（FASAs）和全氟烷基酸（PFAAs）的来源，这些物质在受AFFF影响的地点通常可以检测到。时间采样为包括三甲基或二甲基氨丙基全氟烷磺酰胺在内的多种前体的生物转化提供了证据。此外，发现基于ECF的前体的环境稳定性（即抗转化能力）取决于结构特征，包括全氟烷基链长度、磺酰胺或羧酰胺基团的存在以及连接在氮原子上的官能团（例如羧基烷基支链）。这些发现为源自AFFF的PFAS和其他结构相似的基于ECF的PFAS的转化途径提供了见解，这将有助于管理和修复受遗留AFFF影响地点的PFAS污染。
