JAUE2020-096: Life Cycle Assessment of the Hybrid Rainwater-Graywater (HRG) System Performance

Abstract

As efficient water-saving equipment, the hybrid rainwater-graywater (HRG) systems are received notable attention to cover the water scarcity, especially in developed country. With the service time of HRG increasing, however, its performance will be changed due to various factors. Thus it is necessary to assess the operation status of HRG throughout the life cycle. In this study, the efficient of the HRG which has served for 19 years on a campus is investigated. Yearly non-potable water supplied capacity of HRG is more than 90%, but it only has 56.63% in Aug. In other words, extra 3000 – 8300 m3 tap water must be bought a year during the peak of water consumptions to keep the water supply stable. Water saving efficiency decreases from 51.39 % to 26.05% in 18 years, and annual rainwater utilization of HRG can reach 100% while annual graywater utilization decreases from 29.20% to 14.14%. The reduction of surface runoff increases from 28.27% to 76.67%. These findings not only point out the major factors affecting HRG performance, but provide data support for the design and optimization of HRG.