Department of Energy, Systems, Territory and Construction Engineering (DESTEC), University of Pisa, 56122 Pisa, Italy.
Sci Total Environ. 2023 Nov 1;897:165390. doi: 10.1016/j.scitotenv.2023.165390. Epub 2023 Jul 7.
Nowadays, environmental protection has become a topic of primary importance, and the interest in wastewater treatment plants (WWTPs) has increased due to the need for a paradigm shift from linear to circular economy. The centralization level of wastewater infrastructure is the basis for a successful system. The aim of this study was to investigate the environmental impacts generated from the centralized treatment of wastewater in a tourist area in central Italy. The combined use of BioWin 6.2 simulation software and life cycle assessment (LCA) methodology was implemented to evaluate the potential connection of a small decentralized WWTP to a medium-size centralized facility. Two different scenarios (decentralized system, corresponding to the current situation, and centralized) were evaluated in two separate periods: high season (HS), corresponding to the main tourist season, and low season (LS), which is the period before the main tourist season. Two sensitivity analyses were conducted, assuming different NO emission factors, and considering the period at the end of tourist season, respectively. Although with modest advantages (up to -6 % in pollutant emissions), WWTP connection was the best management option in 10 out of 11 indicators in HS, and 6 out of 11 categories in LS. The study showed that wastewater centralization was promoted by scale factors in HS, as the most impactful consumptions decreased as the degree of centralization increased; on the other hand, the decentralized system was less penalized in LS, as small WWTP was less stressed and energy consuming in this period. Sensitivity analysis confirmed the results obtained. Site-specific conditions can lead to conflicting circumstances, as key parameters may have different behaviors depending on seasonal variations, and the degree of centralization in tourist areas should be addressed by distinguishing separate periods, based on changes in tourist flows and pollution loads.
如今，环境保护已成为首要议题，由于需要从线性经济向循环经济转变，人们对废水处理厂（WWTP）的兴趣日益增加。废水基础设施的集中化程度是成功系统的基础。本研究旨在调查意大利中部旅游区集中处理废水所产生的环境影响。该研究采用 BioWin 6.2 模拟软件和生命周期评估（LCA）方法相结合，评估将小型分散式 WWTP 与中型集中式设施连接的潜力。在两个不同时期评估了两种不同情景（分散式系统，对应当前情况，以及集中式）：旺季（HS），对应主要旅游季节，以及淡季（LS），即主要旅游季节之前的时期。进行了两次敏感性分析，分别假设不同的 NO 排放因子，并考虑旅游季节结束时的时间段。尽管具有适度的优势（污染物排放减少最多可达-6%），但在 HS 中的 11 个指标中有 10 个，以及 LS 中的 11 个类别中的 6 个，WWTP 连接是最佳管理选项。研究表明，在 HS 中，规模因素促进了废水集中化，因为随着集中化程度的提高，最具影响力的消耗会减少；另一方面，在 LS 中，分散式系统受到的惩罚较小，因为在这个时期，小型 WWTP 的压力和能耗较小。敏感性分析证实了所获得的结果。具体地点的情况可能会导致冲突的情况，因为关键参数的行为可能因季节性变化而有所不同，并且应该根据旅游流量和污染负荷的变化，通过区分不同的时期来解决旅游区的集中化程度问题。
