Department of Civil and Environmental Engineering, Auburn University, Auburn, AL 36849, United States.
Department of Geosciences, Auburn University, Auburn, AL 36849, United States.
Sci Total Environ. 2022 Aug 25;836:155524. doi: 10.1016/j.scitotenv.2022.155524. Epub 2022 Apr 27.
Per- and polyfluoroalkyl substances (PFAS) have been previously detected near suspected sources in Alabama, but the overall extent of contamination across the state is unknown. This study evaluated the spatial distribution of 17 PFAS within the ten major river basins in Alabama and provided insights into their transport and fate through a mass flux analysis. Six PFAS were identified in 65 out of the 74 riverine samples, with mean ∑PFAS levels of 35.2 ng L. The highest ∑PFAS concentration of 237 ng L was detected in the Coosa River, a transboundary river that receives discharges from multiple sources in Alabama and Georgia. PFAS distribution was not observed to be uniform across the state: while the Coosa, Alabama, and Chattahoochee rivers presented relatively high mean ∑PFAS concentrations of 191, 100 and 28.8 ng L, respectively, PFAS were not detected in the Conecuh, Escatawpa, and Yellow rivers. Remaining river systems presented mean ∑PFAS concentrations between 7.94 and 24.7 ng L. Although the short-chain perfluoropentanoic acid (PFPeA) was the most detected analyte (88%), perfluorobutanesulfonic acid (PFBS) was the substance with the highest individual concentration of 79.4 ng L. Consistent increases in the mass fluxes of PFAS were observed as the rivers flowed through Alabama, reaching up to 63.3 mg s, indicating the presence of numerous sources across the state. Most of the mass inputs would not have been captured if only aqueous concentrations were evaluated, since concentration is usually heavily impacted by environmental conditions. Results of this study demonstrate that mass flux is a simple and powerful complementary approach that can be used to broadly understand trends in the transport and fate of PFAS in large river systems.
全氟和多氟烷基物质 (PFAS) 此前曾在阿拉巴马州疑似污染源附近检测到，但全州的污染程度尚不清楚。本研究评估了阿拉巴马州十大河流流域内 17 种 PFAS 的空间分布，并通过质量通量分析深入了解了它们的迁移和归宿。在 74 个河流水样中，有 65 个检测到 6 种 PFAS，∑PFAS 浓度的平均值为 35.2ng/L。在库萨河（Coosa River）中检测到的∑PFAS 浓度最高，为 237ng/L，库萨河是一条跨界河流，接收来自阿拉巴马州和佐治亚州多个来源的污水排放。州内的 PFAS 分布并不均匀：虽然库萨河、亚拉巴马河和查塔胡奇河的平均∑PFAS 浓度分别为 191、100 和 28.8ng/L，但 Conecuh、Escatawpa 和 Yellow 河却没有检测到 PFAS。其余河流系统的平均∑PFAS 浓度在 7.94 至 24.7ng/L 之间。尽管短链全氟戊酸（PFPeA）是最常见的检测分析物（88%），但全氟丁烷磺酸（PFBS）的单个浓度最高，为 79.4ng/L。随着河流流经阿拉巴马州，PFAS 的质量通量持续增加，最高可达 63.3mg/s，这表明全州存在大量污染源。如果仅评估水相浓度，就会错过大部分的质量输入，因为浓度通常会受到环境条件的严重影响。本研究结果表明，质量通量是一种简单而强大的补充方法，可用于广泛了解 PFAS 在大型河流系统中的迁移和归宿趋势。
