HDR, 1917 S 67th Street, Omaha NE 68106, USA.
Department of Civil and Environmental Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.
Water Res. 2021 Dec 1;207:117758. doi: 10.1016/j.watres.2021.117758. Epub 2021 Oct 14.
The objective of this study was to quantify potential mitigation of environmental impacts from the operation and construction of wastewater treatment plants (WWTP) from implementing specific design recommendations. The study investigated small WWTPs, many of which are serving slow growing or declining populations. Life Cycle Assessment methodology was used to evaluate and compare the inventory and environmental impacts of nine small WWTP case studies. Detailed inventory data was collected from the facilities' engineering design plans and utility bills. One recommended practice was to avoid significant overdesign by planning for no lower than a 75% capacity utilization by the facilities' end-of-life. A theoretical correction to a 75% capacity utilization was estimated to mitigate 0.4% of lifetime electricity usage and 1% of secondary process concrete for every 1% reduction in design average flow rate. Relatedly, a 0.4% mitigation in the Carcinogenic and Global Warming impacts could be achieved for every 1% reduction in design average flow toward a 75% capacity utilization. Other suggested practices were focused on conveyance, namely, to minimize non-process facility area and to use polyvinyl chloride pipe instead of ductile iron pipe where possible. The latter practice was estimated to mitigate between 1.1 and 4.8% of the Carcinogenic impact in the nine case studies.
本研究旨在量化通过实施具体设计建议来减轻污水处理厂（WWTP）运营和建设对环境的影响。该研究调查了小型 WWTP，其中许多 WWTP 服务于增长缓慢或人口减少的地区。生命周期评估方法用于评估和比较九个小型 WWTP 案例研究的清单和环境影响。详细的清单数据是从设施的工程设计计划和水电费中收集的。一个建议的做法是避免重大的过度设计，规划设施使用寿命结束时的利用率不低于 75%。据估计，将设计平均流量降低 1%，可将生命周期用电的 0.4%和二级工艺混凝土的 1%作为理论校正来缓解 75%的利用率。相关地，通过将设计平均流量降低到 75%的利用率，可以实现每降低 1%设计平均流量就减少 0.4%的致癌和全球变暖影响。其他建议的做法侧重于输送，即尽量减少非工艺设施区域，并在可能的情况下使用聚氯乙烯管而不是球墨铸铁管。据估计，后一种做法可减轻九个案例研究中致癌影响的 1.1%至 4.8%。
