Recent publications have highlighted the ubiquitous presence of unidentified organofluorine compounds, whose environmental occurrence is poorly understood. In this study, wastewater treatment plant (WWTP) effluent and sludge samples from seven countries were analyzed for extractable organofluorine (EOF) and target PFAS, to evaluate which compounds are released back into the environment. Fluorine mass balance analysis of effluent samples (n = 14) revealed that on average 90% of the EOF could not be explained by the 73 PFAS monitored in this investigation. The levels of EOF in effluent (324–1460 ng of F/L) and sludge (39–210 ng of F/g of dry weight) indicate that a substantial amount of organofluorine compounds is released back into nature. A commonly overlooked PFAS class, ultra-short-chain PFCAs, accounted for 4% of EOF on average, while the remaining 71 compounds explained only a further 6% of EOF on average. The highest number of PFAS was detected in the effluent dissolved phase (37), compared to 29 and 23 PFAS in sludge and effluent particulate phase, respectively. The increased concentrations of EOF in both WWTP effluent and sludge are of concern, as the chemical species contained therein remain largely unknown, and thus, their potential health and environmental risks cannot be assessed.

中文翻译：

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北欧国家污水和污泥的氟质量平衡分析

最近的出版物强调了普遍存在的未知有机氟化合物，其环境发生情况知之甚少。在这项研究中，对来自七个国家的污水处理厂 (WWTP) 流出物和污泥样品进行了可提取有机氟 (EOF) 和目标 PFAS 的分析，以评估哪些化合物会被释放回环境中。流出物样品的氟质量平衡分析 ( n= 14) 表明，平均 90% 的 EOF 无法用本次调查中监测的 73 种 PFAS 来解释。流出物（324–1460 ng F/L）和污泥（39–210 ng F/g 干重）中的 EOF 水平表明大量有机氟化合物被释放回大自然。一个普遍被忽视的 PFAS 类，超短链 PFCA，平均占 EOF 的 4%，而其余 71 种化合物平均仅解释了 EOF 的 6%。在污水溶解相中检测到的 PFAS 数量最多 (37)，而在污泥和污水颗粒相中分别检测到 29 和 23 PFAS。污水处理厂出水和污泥中 EOF 浓度的增加令人担忧，因为其中包含的化学物质在很大程度上仍然未知，因此，