Institute of Chemical, Environmental and Bioscience Engineering E166/5/3, TU Wien, Gumpendorferstraße 1a, A-1060 Vienna, Austria; Center for Water Resource Systems E222, TU Wien, Karlsplatz 13, A-1040 Vienna, Austria.
Institute of Hydraulic Engineering and Water Resources Management E222/2, TU Wien, Karlsplatz 13, A-1040 Vienna, Austria.
Sci Total Environ. 2021 May 10;768:144278. doi: 10.1016/j.scitotenv.2020.144278. Epub 2020 Dec 24.
Rivers are important for drinking water supply worldwide. However, they are often impacted by pathogen discharges via wastewater treatment plants (WWTP) and combined sewer overflows (CSO). To date, accurate predictions of the effects of future changes and pollution control measures on the microbiological water quality of rivers considering safe drinking water production are hindered due to the uncertainty of the pathogen source and transport variables. The aim of this study was to test an integrative approach for an improved understanding of these effects, i.e. climate change and population growth as well as enhanced treatment at WWTPs and/or prevention of CSOs. We applied a significantly extended version of QMRAcatch (v1.0 Python), a probabilistic-deterministic model that combines fate and transport modelling with quantitative microbial infection risk assessment. The impact of climatic changes until the period 2035-2049 was investigated by a conceptual semi-distributed hydrological model, based on regional climate model outputs. QMRAcatch was calibrated and validated using site- and source-specific data (human-associated genetic microbial source tracking marker and enterovirus). The study showed that the degree to which future changes affect drinking water safety strongly depends on the type and magnitude of faecal pollution sources and are thus highly site- and scenario-specific. For example, if the load of pathogens from WWTPs is reduced through enhanced treatment, climate-change driven increases in CSOs had a considerable impact. Preventing CSOs and installing enhanced treatment at the WWTPs together had the most significant positive effect. The simultaneous consideration of source apportionment and concentrations of reference pathogens, focusing on human-specific viruses (enterovirus, norovirus) and cross-comparison with bacterial and protozoan pathogens (Campylobacter, Cryptosporidium), was found crucial to quantify these effects. While demonstrated here for a large, wastewater-impacted river, the approach is applicable at other catchments and pollution sources. It allows assessing future changes and selecting suitable pollution control measures for long-term water safety planning.
河流是全球饮用水供应的重要组成部分。然而，它们经常受到来自污水处理厂（WWTP）和合流制污水溢流（CSO）的病原体排放的影响。迄今为止，由于病原体源和输移变量的不确定性，准确预测未来变化和污染控制措施对考虑安全饮用水生产的河流微生物水质的影响受到阻碍。本研究旨在测试一种综合方法，以更好地了解这些影响，即气候变化和人口增长，以及 WWTP 处理的加强和/或 CSO 的预防。我们应用了 QMRAcatch（v1.0 Python）的显著扩展版本，这是一种将命运和传输建模与定量微生物感染风险评估相结合的概率-确定性模型。基于区域气候模型输出，通过概念性半分布式水文模型研究了直到 2035-2049 年期间气候变化的影响。使用基于特定地点和来源的数据（与人相关的遗传微生物源追踪标记物和肠道病毒）对 QMRAcatch 进行了校准和验证。研究表明，未来变化对饮用水安全的影响程度强烈取决于粪便污染来源的类型和大小，因此具有高度的地点和情景特异性。例如，如果通过加强处理减少 WWTP 的病原体负荷，气候变化驱动的 CSO 增加将产生相当大的影响。防止 CSO 并在 WWTP 安装强化处理一起具有最显著的积极影响。同时考虑源分配和参考病原体的浓度，重点关注人类特异性病毒（肠道病毒、诺如病毒），并与细菌和原生动物病原体（弯曲杆菌、隐孢子虫）进行交叉比较，被发现对于量化这些影响至关重要。虽然在这里针对一条大型、受废水影响的河流进行了演示，但该方法适用于其他集水区和污染源。它允许评估未来的变化并为长期水安全规划选择合适的污染控制措施。
