System Research In Reclaimed Water Utilization And Extension Of Xi'an

At present, water shortage and water pollution has become a serious constraint to sustainable development of cities. Sewage treatment and water recycling is an artificial simulation and strengthening of the water natural cycle. Recycling of urban sewage is one of the effective ways to reduce water pollution, improve the ecological environment and solve the urban water shortage, which was not only technically feasible but also economic rationality. The development of water recycling and promotion of water resources is the inevitable choice to achieve the sustainable use of limited water resources, enhance water resources self-reliance and the security extent. Based on this, this paper take Xi'an as study objects. studied the use of reclaimed water in the theory and application from background of promote the use of reclaimed water, the renewable water resources investigation and analysis of wastewater, health risk assessment of reclaimed water system, optimize decision-making model and culture and information technology support system. Its main contents include:(1) Combined with the current status of water resources in Xi'an, comprehensively analyzed the balance of supply and demand of water resources in Xi'an, discussed the impact of water shortages and the way to solve the water shortage, and showed the feasibility and urgency of the Xi'an municipal wastewater recycling. In accordance with Water-saving social construction basic theories, established the main water-saving tasks and objectives for various industries in Xi'an.(2) Carried on the preliminary examination to Xi'an's three Sewage treatment plant's water quality and the water volume by the typical survey method. According to investigation of reclaimed water source volume, water quality as well as resurgent water user, investigation result was analyzed objectively using statistics method.(3) Cleared direction of reclaimed water utilization of Xi'an namely:industrial, landscape water, municipal utility, the agriculture and the underground recharge and so on. Analyzed the concentration and decentralized approach of reclaimed water utilization and Analyzed the sewage amount of Xi'an, the present situation and the demand of sewage reclamation and utilization.(4) Putted forward a more comprehensive indicator system of the health risk assessment and the conventional evaluation methods of the promotion and use of reclaimed water in the health risks (exposure assessment and toxicity assessment), in accordance with the uncertainty of the risk assessment process, proposed the uncertainty health risk assessment methods. Combined with quantity and quality of the reclaimed water, renewable water treatment system, water pipes network and terminal water users, discussed the use of security technology in the reclaimed water utilization.(5) Studied the Circular Economy and Value theory of Reclaimed Water, combined with the price status and constituent elements of the reclaimed water utilization, established the units of water cost model and average cost pricing model, measured the price of reclaimed water in Xi'an.(6) Propounded the decision-making model of the requisite capacity for regenerative water users, according to the basic principles of system theory, using of linear programming methods, established the objective function and the binding equation of distribution, got the relationship between the plant of renewable water and the area of water-using,to establish a optimal model of cost and maximum water.(7)Advocated the coalescence of engineering-oriented measures and non-engineering-oriented measures, the effective link of natural and social sciences, to support and promote the use of urban regeneration effectively and scientifically by building a support system of urban water-saving culture and a information-based services platform of urban reclaimed water.