Per- and polyfluoroalkyl substances (PFASs), as the “Forever Chemicals”, are ubiquitous in environments, showing serious threaten to ecological safety and human health. Urban river networks are critical systems for PFASs behaviors. However, the mechanisms of discharge and multimedia transports of PFASs remain unclear, which hinder effective management in megacity. In this study, based on the field measurement and discharge estimation, we developed a dynamic model accounting for the hydrology and multimedia processes to simulate the transport and fate of PFASs in river networks of Shanghai. Results showed that PFASs were widely detected in the river networks. The discharge of representative PFASs (PFOA and PFOS) increased from 1990 to 2022, and high concentrations were observed at upstream basin, local industrial zones and intense human activities areas. The coupled model revealed dynamic distribution of PFOA and PFOS in the water and sediment. The concentration in water and sediment showed an upward trend before 2005 and remained stable until 2022. Land use types, population densities, GDP values and water flow were proven to be significant factors and should be considered when constructing the model. The research provides new insights for accurate simulation of urban multi-media environmental processes and a scientific basis for PFASs management and control in megacity.

中文翻译：

---

用于模拟 PFAS 在特大城市上海河网中运输和归宿的耦合水文多媒体模型


全氟烷基和多氟烷基物质 （PFAS） 作为“永久化学品”，在环境中无处不在，对生态安全和人类健康构成严重威胁。城市河流网络是 PFAS 行为的关键系统。然而，PFAS 的排放和多媒体运输机制仍不清楚，这阻碍了特大城市的有效管理。在这项研究中，基于现场测量和流量估算，我们开发了一个动态模型，用于解释水文和多媒体过程，以模拟 PFAS 在上海河网中的运输和归宿。结果表明，PFAS 在河流网络中被广泛检测到。从 1990 年到 2022 年，代表性 PFAS（PFOA 和 PFOS）的排放量有所增加，在上游流域、当地工业区和人类活动密集区观察到高浓度。耦合模型揭示了 PFOA 和 PFOS 在水和沉积物中的动态分布。2005 年之前，水和沉积物中的浓度呈上升趋势，直到 2022 年保持稳定。土地利用类型、人口密度、GDP 值和水流量被证明是重要因素，在构建模型时应考虑。该研究为准确模拟城市多媒体环境过程提供了新的见解，为特大城市 PFASs 的管理和控制提供了科学依据。