Ghimire Santosh R, Johnston John M, Ingwersen Wesley W, Sojka Sarah
ORISE Postdoctoral Research Participant, U.S. Environmental Protection Agency, Office of Research and Development, 960 College Station Rd., Athens, GA 30605, USA.
U.S. Environmental Protection Agency, Office of Research and Development, 960 College Station Rd., Athens, GA 30605, USA.
J Clean Prod. 2017 May 10;151:74-86. doi: 10.1016/j.jclepro.2017.02.025.
Building upon previously published life cycle assessment (LCA) methodologies, we conducted an LCA of a commercial rainwater harvesting (RWH) system and compared it to a municipal water supply (MWS) system adapted to Washington, D.C. Eleven life cycle impact assessment (LCIA) indicators were assessed, with a functional unit of 1 m of rainwater and municipal water delivery system for toilets and urinals in a four-story commercial building with 1000 employees. Our assessment shows that the benchmark commercial RWH system outperforms the MWS system in all categories except Ozone Depletion. Sensitivity and performance analyses revealed pump and pumping energy to be key components for most categories, which further guides LCIA tradeoff analysis with respect to energy intensities. Tradeoff analysis revealed that commercial RWH performed better than MWS in Ozone Depletion if RWH's energy intensity was less than that of MWS by at least 0.86 kWh/m (249% of the benchmark MWS energy usage at 0.35 kWh/m). RWH also outperformed MWS in Metal Depletion and Freshwater Withdrawal, regardless of energy intensities, up to 5.51 kWh/m. An auxiliary commercial RWH system with 50% MWS reduced Ozone Depletion by 19% but showed an increase in all other impacts, which were still lower than benchmark MWS system impacts. Current models are transferrable to commercial RWH installations at other locations.
基于先前发表的生命周期评估（LCA）方法，我们对一种商业雨水收集（RWH）系统进行了生命周期评估，并将其与适用于华盛顿特区的市政供水（MWS）系统进行了比较。评估了11个生命周期影响评估（LCIA）指标，功能单位为一栋有1000名员工的四层商业建筑中用于卫生间和小便器的1立方米雨水和市政供水系统。我们的评估表明，除了臭氧消耗类别外，基准商业雨水收集系统在所有类别中均优于市政供水系统。敏感性和性能分析表明，泵和抽水能源是大多数类别的关键组成部分，这进一步指导了关于能源强度的生命周期影响评估权衡分析。权衡分析表明，如果雨水收集系统的能源强度比市政供水系统至少低0.86千瓦时/立方米（市政供水系统基准能源使用量为0.35千瓦时/立方米时的249%），则商业雨水收集系统在臭氧消耗方面的表现优于市政供水系统。无论能源强度如何，在金属消耗和淡水提取方面，雨水收集系统也优于市政供水系统，最高可达5.51千瓦时/立方米。一个与50%市政供水系统相结合的辅助商业雨水收集系统可使臭氧消耗减少19%，但在所有其他影响方面均有所增加，不过仍低于市政供水系统基准影响。当前模型可转移到其他地点的商业雨水收集装置。
