Research On The Sewage Reuse In Baoji

Water resource is an important natural and economical resource for domestic and industrial use, Baoji is located in the west of Shaan'xi province, and is the second city of Shaan'xi. Because the climate of northwest is dry and the rainfall is lower, the water resource situation of this city is not sustainable. Although there are many rivers in the city, the water pollution is very serious, and the water resource which can be used is limited. The supply and demand of water resource is out of balance. So it can't coordinate with society and economy. To take sewage which is treated as a second water resource, is benefit for environmental protection and water saving.By calculate the total quantity of water resource and which can be used, the paper compared it with water demand. To solve the problem of water supply and demand paradox, the recovery of sewage is researched in order to relieve the paradox, and content to the standard of national ecological city. The main content of the paper is as follows:By collecting data and research, the present situation and the plan of the water supply system, drainage system, and ecological environment construction are analyzed. Many problems are pointed out, such as: water supply is lower, water pollution is serious, and the areas of grassland are not enough.The paper calculated the quantity of surface and ground water, and the total quantity of water resource. The water resource of which can be used is more important, so its quantity is also been calculated. In order to guarantee the normal ecological cycle of rivers, the basic water demand of rivers and flood quantity should be calculated and minused from total amount. From the conclusion of the calculation, the paper analysis the features and problems of water resource. The total amount of water resource of this district is scarce.The paper calculated the water demand respectively from domestic, industrial and environmental facets. The methods are referring to correlation method, tendency method, and grey model method and so on. Compared with water supply in the district, the demand and supply is out of balance. So Wastewater reuse is proposed as a second water resource.As a new position of water allocation, the feasibility of Wastewater is analyzed from the aspect of national ecological city construction. The standard of ecological city is that the sewage treatment percent should be up to 70%, and the Wastewater reuse should be up to 30%. From environmental aspect, use one-dimensional dilute self-purification model to predict the water quality of Weihe River. The conclusion is that the absolutely treatment of sewage can improve water quality. And from economical aspect, use the capitalized cost model to compare the price of the recycle Wastewater with that of fresh water.Use recycled Wastewater to supplement grassland and lakes. This strategy can save a lot of water resource, and is benefit for the construction of ecological environment city.