4. A Real Case of Water Reuse Through a Water Cycle

This chapter introduces a novel model case of water cycle management for a semi-decentralized water and wastewater system with reclaimed water use in a university campus in Xi’an, China where less than 3,000 m³/d of groundwater is the only freshwater source for up to 35,000 population and 80 ha area with 60 % green coverage. Under the constraints of limited source water and large water demand for potable and non-potable purposes, the water system was designed by integrating water supply, sewerage, water reclamation and reuse, and water landscaping in one framework, utilizing the landscaping lake as a buffer zone in a mimicking natural water cycle with a high recycling ratio, and combining engineering and natural processes for water quality control. With the freshwater used only for potable purposes and the reclaimed water for all non-potable uses, the water application efficiency was doubled and safety water use was secured.