Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401, United States.
Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331, United States.
Environ Sci Technol. 2021 Jan 5;55(1):313-323. doi: 10.1021/acs.est.0c04473. Epub 2020 Dec 22.
Soil and groundwater from an aqueous film-forming foam (AFFF)-impacted site were sampled at high resolution ( = 105 for soil, = 58 for groundwater) and analyzed for an extensive list of anionic, zwitterionic, and cationic poly- and perfluoroalkyl substances (PFASs). Spatial trends for perfluoroalkyl acids and many precursors enabled a better understanding of PFAS composition, transport, and transformation. All PFASs without analytical standards were semi-quantified. Summed PFAS and individual PFAS concentrations were often higher at depth than near the surface in soil and groundwater. Zwitterionic and cationic compounds composed a majority of the total PFAS mass (up to 97%) in firefighter training area (FTA) soil. Composition of PFAS class, chain length, and structural isomers changed with depth and distance from the FTA, suggesting in situ transformation and differential transport. The percentage of branched perfluorooctane sulfonate increased with depth, consistent with differential isomeric transport. However, linear perfluorooctanoic acid (PFOA) was enriched, suggesting fluorotelomer precursor transformation to linear PFOA. Perfluorohexane sulfonamide, a potential transformation product of sulfonamide-based PFASs, was present at high concentrations (maximum 448 ng/g in soil, 3.4 mg/L in groundwater). Precursor compounds may create long-term sources of perfluoroalkyl acids, although many pathways remain unknown; precursor analysis is critical for PFAS fate and transport understanding.
采集了受水性成膜泡沫 (AFFF) 影响的场地的土壤和地下水样本，分辨率很高（土壤为 = 105，地下水为 = 58），并对大量阴离子、两性离子和阳离子多氟和全氟烷基物质 (PFAS) 进行了分析。全氟烷基酸和许多前体的空间趋势有助于更好地理解 PFAS 的组成、迁移和转化。所有没有分析标准的 PFAS 都进行了半定量分析。在土壤和地下水中，总和单个 PFAS 的浓度通常在深度处比在表面附近更高。两性离子和阳离子化合物构成了消防员训练区 (FTA) 土壤中总 PFAS 质量的大部分（高达 97%）。PFAS 类、链长和结构异构体的组成随深度和距离 FTA 而变化，表明存在原位转化和差异传输。支化全氟辛烷磺酸的百分比随深度增加而增加，与差异异构体传输一致。然而，线性全氟辛酸 (PFOA) 却被富集，表明基于磺酰胺的 PFAS 向线性 PFOA 的转化。全氟己烷磺酰胺是磺酰胺基 PFAS 的潜在转化产物，其浓度很高（土壤中最高为 448ng/g，地下水中为 3.4mg/L）。前体化合物可能会产生长期的全氟烷基酸来源，尽管许多途径仍不清楚；前体分析对于 PFAS 的命运和传输理解至关重要。
