Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, E1A 07-03, Singapore 117576, Singapore.
Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, E1A 07-03, Singapore 117576, Singapore; Environment Building, 40 Scott Road, Public Utilities Board (PUB), Singapore.
Environ Pollut. 2017 Aug;227:397-405. doi: 10.1016/j.envpol.2017.04.091. Epub 2017 May 6.
Understanding the sources, occurrence and sinks of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in the urban water cycle is important to protect and utilize local water resources. Concentrations of 22 target PFASs and general water quality parameters were determined monthly for a year in filtered water samples from five tributaries and three sampling stations of an urban water body. Of the 22 target PFASs, 17 PFASs were detected with a frequency >93% including PFCAs: C4-C12 perfluoroalkyl carboxylates, C4, C6, C8, and C10 perfluoroalkane sulfonates, perfluorooctane sulfonamides and perfluorooctane sulfonamide substances (FOSAMs), C10 perfluoroalkyl phosphonic acid (C10 PFPA), 6:2 fluorotelomer sulfonic acid (6:2 FTSA) and C8/C8 perfluoroalkyl phosphinic acid (C8/C8-PFPIA). The most abundant PFASs in water were PFBS (1.4-55 ng/L), PFBA (1.0-23 ng/L), PFOS (1.5-24 ng/L) and PFOA (2.0-21 ng/L). In the tributaries, PFNA concentrations ranged from 1.2 to 87.1 ng/L except in the May 2013 samples of two tributaries, which reached 520 and 260 ng/L. Total PFAS concentrations in the sediment samples ranged from 1.6 to 15 ng/g d.w. with EtFOSAA, PFDoA, PFOS and PFDA being the dominant species. Based on water and sediment data, two types of sources were inferred: one-time or intermittent point sources and continuous non-point sources. FOSAMs and PFOS released continually from non-point sources, C8/C8 PFPIA, PFDoA and PFUnA was released from point sources. The highly water soluble short-chain PFASs including PFBA, PFPeA and PFBS remained predominantly in the water column. The factors governing solution phase concentrations appear to be compound hydrophobicity and sorption to suspended particles. Correlation of the dissolved phase concentrations with precipitation data suggested stormwater was a significant source of PFBA, PFBS, PFUnA and PFDoA. Negative correlations with precipitation indicated sources feeding FOSAA and FOSA directly into the tributaries.
了解城市水循环中全氟和多氟烷基物质 (PFAS) 的来源、发生和汇是保护和利用当地水资源的重要前提。本研究在一年的时间内，每月对来自城市水体的 5 条支流和 3 个采样点的过滤水样中的 22 种目标 PFAS 浓度和一般水质参数进行了测定。在所测定的 22 种目标 PFAS 中，17 种 PFAS 的检出率超过 93%，包括全氟羧酸（C4-C12 全氟烷基羧酸）、全氟烷磺酸（C4、C6、C8 和 C10 全氟烷磺酸）、全氟辛烷磺酰胺和全氟辛烷磺酰胺物质（FOSAMs）、全氟辛基膦酸（C10 PFPA）、6:2 氟代硫酸（6:2 FTSA）和 C8/C8 全氟烷基膦酸（C8/C8-PFPIA）。水中最丰富的 PFAS 为 PFBS（1.4-55ng/L）、PFBA（1.0-23ng/L）、PFOS（1.5-24ng/L）和 PFOA（2.0-21ng/L）。在支流中，PFNA 浓度范围为 1.2-87.1ng/L，除了两条支流在 2013 年 5 月的样本中，浓度分别达到 520ng/L 和 260ng/L。沉积物样品中总 PFAS 浓度范围为 1.6-15ng/g dw，其中 EtFOSAA、PFDoA、PFOS 和 PFDA 为主要成分。基于水和沉积物数据，推断存在两种类型的来源：一次性或间歇性点源和连续非点源。FOSAMs 和 PFOS 不断地从非点源释放，C8/C8-PFPIA、PFDoA 和 PFUnA 从点源释放。高度水溶性的短链 PFAS 包括 PFBA、PFPeA 和 PFBS 主要保留在水柱中。影响溶液相浓度的因素似乎是化合物疏水性和对悬浮颗粒的吸附。与降水数据的相关性表明，雨水是 PFBA、PFBS、PFUnA 和 PFDoA 的重要来源。与降水呈负相关表明，FOSAA 和 FOSA 直接从支流中获取来源。
