Optimum Reconstruction Of Secondary Water-supply Systems In City

With the aim of optimal reconstruction of city secondary water supply systems, this paper analyzed water pollution actuality, causes and reconstruction methods of secondary water-supply., systemically. Then, Analytical Hierarchy Process is used to value reconstruction methods. Last, optimal model of secondary water-supply has been built up, expecting to receive the best result in economical, technological and social benefits.First, starting with running actuality of secondary water supply systems, by analysis of the water quality actuality, the author summarized causes and mutual influences.Second, according to water pollution causes of secondary water supply,nine reconstruction methods have been brought forward, and this paper introduced it's applicable arrange,advantages and disadvantages.Third because reconstruction methods are influenced by economy, technology and social environment, and some of these can't be described quantificationally, it's difficult to select. In order to resolve these difficulties, the author uses Analytical Hierarchy Process to evaluate these advantages and disadvantages. It directs select reconstruction methods in engineering.Last, on base of studies, optimal model is built up to idiographic reconstruction methods of secondary water supply. Take Tianjin as a sample the author introduced the process of building up model and resolving it by lingo. From analysis of the result, we can receive that on condition of guaranteeing water quantity, water pressure and water quality,on the limit of funds,we can make more 19.6% and 13.6% people receive benefits earlierly.As a word, the proplem of reconstruction of secondary water supply is huge and complicated. So it's influenced and limited by many fatros in engineering. How to arrange limlited funds and receive much social-econol economal benefits, this paper use Analytical Hierarchy Process to estimate reconstruction methods'advantages and disadvantages, and built up optimal model, It has directions to select reconstruction methods in engineering.