Department of Civil and Natural Resources Engineering, University of Canterbury, Christchurch, New Zealand.
Civil and Environmental Engineering Department, South Dakota School of Mines and Technology, Rapid City, SD, USA.
J Environ Manage. 2015 Feb 1;149:236-44. doi: 10.1016/j.jenvman.2014.10.025. Epub 2014 Nov 12.
Stormwater treatment technologies to manage runoff during rain events are primarily designed to reduce flood risks, settle suspended solids and concurrently immobilise metals and nutrients. Life Cycle Assessment (LCA) is scarcely documented for stormwater systems despite their ubiquitous implementation. LCA modelling quantified the environmental impacts associated with the materials, construction, transport, operation and maintenance of different stormwater treatment systems. A pre-fabricated concrete vortex unit, a sub-surface sandfilter and a raingarden, all sized to treat a functional unit of 35 m(3) of stormwater runoff per event, were evaluated. Eighteen environmental mid-point metrics and three end-point 'damage assessment' metrics were quantified for each system's lifecycle. Climate change (kg CO2 eq.) dominated net environmental impacts, with smaller contributions from human toxicity (kg 1,4-DB eq.), particulate matter formation (kg PM10 eq.) and fossil depletion (kg oil eq.). The concrete unit had the highest environmental impact of which 45% was attributed to its maintenance while impacts from the sandfilters and raingardens were dominated by their bulky materials (57%) and transport (57%), respectively. On-site infiltrative raingardens, a component of green infrastructure (GI), had the lowest environmental impacts because they incurred lower maintenance and did not have any concrete which is high in embodied CO2. Smaller sized raingardens affording the same level of stormwater treatment had the lowest overall impacts reinforcing the principle that using fewer resources reduces environmental impacts. LCA modelling can serve as a guiding tool for practitioners making environmentally sustainable solutions for stormwater treatment.
雨水事件中用于管理径流的雨水处理技术主要旨在降低洪水风险、沉淀悬浮固体，同时固定金属和养分。尽管雨水系统已广泛应用，但生命周期评估 (LCA) 对此却鲜有记录。LCA 模型量化了与不同雨水处理系统的材料、施工、运输、运行和维护相关的环境影响。评估了一个预制混凝土涡流单元、一个地下砂滤器和一个雨水花园，所有这些都设计用于处理每 35 m³事件的雨水径流量的功能单元。对每个系统生命周期的十八个环境中点指标和三个终点“损害评估”指标进行了量化。气候变化 (kg CO2 eq.) 主导了净环境影响，而人类毒性 (kg 1,4-DB eq.)、颗粒物形成 (kg PM10 eq.) 和化石消耗 (kg 石油 eq.) 的贡献较小。混凝土单元的环境影响最大，其中 45%归因于其维护，而砂滤器和雨水花园的影响则主要归因于其体积庞大的材料 (57%) 和运输 (57%)。现场渗透雨水花园是绿色基础设施 (GI) 的一个组成部分，具有最低的环境影响，因为它们的维护成本较低，并且没有高含量 CO2 的混凝土。提供相同雨水处理水平的较小尺寸的雨水花园具有最低的整体影响，这强化了使用较少资源可减少环境影响的原则。LCA 模型可以作为从业者的指导工具，为雨水处理提供环境可持续的解决方案。
