Tsoukalas I K, Makropoulos C K, Michas S N
Department of Water Resources and Environmental Engineering, National Technical University of Athens, Heroon Polytechneiou 5, Zographou GR-15780, Greece E-mail:
Hydroexigiantiki Consultants Engineers, 3 Evias str, Marousi GR-15125, Greece.
Water Sci Technol. 2017 Dec;76(11-12):3351-3357. doi: 10.2166/wst.2017.487.
Rapid urbanization affecting demand patterns, coupled with potential water shortages due to supply side impacts of climatic changes, has led to the emergence of new technologies for water and wastewater reuse. Sewer mining (SM) is a novel decentralized option that could potentially provide non-potable water for urban uses, including for example the irrigation of urban green spaces, providing a mid-scale solution to effective wastewater reuse. SM is based on extracting wastewater from local sewers and treatment at the point of demand and entails in some cases the return of treatment residuals back to the sewer system. Several challenges are currently in the way of such applications in Europe, including public perception, inadequate regulatory frameworks and engineering issues. In this paper we consider some of these engineering challenges, looking at the sewer network as a system where multiple physical, biological and chemical processes take place. We argue that prior to implementing SM, the dynamics of the sewer system should be investigated in order to identify optimum ways of deploying SM without endangering the reliability of the system. Specifically, both wastewater extraction and sludge return could result in altering the biochemical process of the network, thus unintentionally leading to degradation of the sewer infrastructure. We propose a novel Monte-Carlo based method that takes into account both spatial properties and water demand characteristics of a given area of SM deployment while simultaneously accounting for the variability of sewer network dynamics in order to identify potential locations for SM implementation. The outcomes of this study suggest that the method can provide rational results and useful guidelines for upscale SM technologies at a city level.
快速城市化影响需求模式，再加上气候变化对供应端的影响导致潜在的水资源短缺，催生了水和废水回用的新技术。下水道采矿（SM）是一种新型的分散式方案，有可能为城市用途提供非饮用水，例如用于城市绿地灌溉，为有效的废水回用提供一种中等规模的解决方案。SM基于从当地下水道提取废水并在需求点进行处理，在某些情况下还需要将处理后的残余物返回下水道系统。目前在欧洲，此类应用面临若干挑战，包括公众认知、监管框架不完善以及工程问题。在本文中，我们考虑其中一些工程挑战，将下水道网络视为一个发生多种物理、生物和化学过程的系统。我们认为，在实施SM之前，应研究下水道系统的动态变化，以确定在不危及系统可靠性的情况下部署SM的最佳方式。具体而言，废水提取和污泥回流都可能改变网络的生化过程，从而无意中导致下水道基础设施的退化。我们提出了一种基于蒙特卡洛的新方法，该方法考虑了给定SM部署区域的空间特性和用水需求特征，同时考虑下水道网络动态变化的可变性，以确定SM实施的潜在地点。本研究结果表明，该方法可为城市层面的大规模SM技术提供合理结果和有用指导。
