European Commission, Joint Research Centre, Ispra, Italy.
Technical University of Denmark, Kgs. Lyngby, Denmark.
Sci Total Environ. 2022 Dec 1;850:157593. doi: 10.1016/j.scitotenv.2022.157593. Epub 2022 Jul 29.
In this contribution, we analyse scenarios of advanced wastewater treatment for the removal of micropollutants. By this we refer to current mainstream, broad spectrum processes including ozonation and sorption onto activated carbon. We argue that advanced treatment requires properly implemented tertiary (nutrient removal) treatment in order to be effective. We review the critical aspects of the main advanced treatment options, their advantages and disadvantages. We propose a quantification of the costs of implementing advanced treatment, as well as upgrading plants from secondary to tertiary treatment when needed, and we illustrate what drives the costs of advanced treatment for a set of standard configurations. We propose a cost function to represent the total costs (investment, operation and maintenance) of advanced treatment. We quantify the implications of advanced treatment in terms of greenhouse gas emissions. Based on the indicators of total toxic discharge, toxicity at the discharge points and toxicity across the stream network discussed in Pistocchi et al. (2022), we compare costs and effectiveness of different scenarios of advanced treatment. In principle the total toxic load and toxicity at the points of discharge could be reduced by about 75 % if advanced treatment processes were implemented virtually at all wastewater treatment plants, but this would entail costs of about 4 billion euro/year for the European Union as a whole. We consider a "compromise" scenario where advanced treatment is required at plants of 100 thousand population equivalents (PE) or larger, or at plants between 10 and 100 thousand PE if the dilution ratio at the discharge point is 10 or less. Under this scenario, the length of the stream network exposed to high toxicity would not increase significantly compared to the previous scenario, and the other indicators would not deteriorate significantly, while the costs would remain at about 1.5 billion Euro/year. Arguably, costs could be further reduced, without a worsening of water quality, if we replace a local risk assessment to generic criteria of plant capacity and dilution in order to determine if a WWTP requires advanced treatment.
在本贡献中，我们分析了去除微污染物的高级废水处理方案。通过这种方式，我们指的是当前主流的广谱处理方法，包括臭氧氧化和活性炭吸附。我们认为，高级处理需要适当实施三级（营养物去除）处理才能有效。我们审查了主要高级处理选择方案的关键方面，及其优缺点。我们提出了实施高级处理的成本量化，以及在需要时将工厂从二级升级到三级处理，并且说明了一组标准配置中驱动高级处理成本的因素。我们提出了一个成本函数来表示高级处理的总成本（投资、运营和维护）。我们量化了高级处理的温室气体排放影响。基于 Pistocchi 等人讨论的总毒性排放指标、排放点毒性和整个流域网络毒性（2022 年），我们比较了不同高级处理方案的成本和效果。原则上，如果几乎所有污水处理厂都实施了高级处理工艺，那么总毒性负荷和排放点毒性可以减少约 75%，但这将需要整个欧盟每年约 40 亿欧元的成本。我们考虑了一种“妥协”方案，即只有在 10 万人口当量（PE）或更大的工厂或在排放点稀释比为 10 或以下的 10 万至 100 万 PE 之间的工厂需要进行高级处理。在这种情况下，与前一种方案相比，暴露于高毒性的流域网络长度不会显著增加，其他指标也不会显著恶化，而成本仍将保持在每年约 15 亿欧元。可以说，如果我们用工厂容量和稀释的通用标准代替局部风险评估来确定是否需要进行高级处理，那么在不降低水质的情况下，成本可以进一步降低。
