Potential Analysis And Eco-efficiency Evaluation Of Reclaimed Water Reuse In Xi'an

The problem of water shortage has been the focus of global attention.The supply and demand of water resources is related to the national economy and people's livelihood.With the rapid development of urban economy,the problem of water pollution is becoming more and more serious.At this time,as an alternative source of urban water supply,reclaimed water can not only alleviate the shortage of water resources,but also reduce water pollution.At present,it is an indisputable fact that the reuse of reclaimed water can alleviate the shortage of urban water resources,but there are few studies on the potential and benefits of urban reclaimed water reuse in China,and no unified idea has been formed.As the quality of reclaimed water is different from other traditional water sources,the demand may be limited.How much is the demand for reclaimed water in a city,and the possible benefits of reclaimed water reuse will affect the long-term planning of urban reclaimed water reuse,which needs further research.In this paper,Xi'an city is taken as the research area,the grey prediction model is constructed to predict the demand of Xi'an renewable water and explore the potential of Xi'an renewable water reuse;then,the ecological efficiency value is taken as the measurement index,the SBM model considering the unexpected output is constructed to evaluate the comprehensive benefits of urban renewable water reuse,such as economic andenvironmental benefits,and the Tobit regression model is used to predict the potential of Xi'an renewable water reuse The influencing factors of state efficiency are studied in depth,and the case study of Hancheng Lake in Xi'an is carried out.The results show that:(1)there is great potential for the reuse of reclaimed water in Xi'an.From the technical point of view,Xi'an has made great progress in the reuse of reclaimed water,but there are still some defects in the relevant management system,laws and regulations,which need to be further improved;from the perspective of the supply and demand balance of the forecast of the demand for reclaimed water,Xi'an may have a gap of 81.3179 million cubic meters in the demand for reclaimed water in 2020.(2)There are considerable comprehensive benefits in the reuse of reclaimed water for urban landscape water.Compared with the traditional water source,the introduction of reclaimed water has increased the ecological efficiency of Hancheng Lake by three times;(3)the industrial structure,tourist reception and management level have a positive impact on the ecological efficiency,while the investment level and environmental policy have a negative impact.It is suggested that Xi'an should increase the investment in the construction of supporting facilities related to reclaimed water,establish and improve the relevant legal system and management supervision system,so that reclaimed water can be fully included in the water resource management system;in addition,for enterprises or scenic spots that use reclaimed water to reuse landscape water,it is suggested that industrial structure and investment level can be adjusted,tourist reception scale can be expanded,and environmental policies can be standardized High ecological efficiency of reclaimed water after reuse.