Location Of The Central Plant And Operation Mechanism Of Joint Operation Wastewater Treatment Plants In Small Towns

Along with the economic development and the improvement of people’s livingstandard in small towns, water pollution problems become more and more serious.Recently, many scholars at home and abroad have done lots of researches about waterpollution treatment technology. A large number of wastewater treatment plants have alsobeen built in many small towns. However, at present, people paid attention to theconstruction of wastewater treatment plants and despised the operation of them. As aresult, the operation cost became high, the operation technical level was relativelybackward and many wastewater treatment plants in small towns have to stop running.In view of the features that small scale，quantity，decentralization and lowoperation efficiency，From the point of view of operation and management，it proposedjoint operation mode for wastewater treatment plants in small towns, and researched onlocation of the central plant and operation mechanism.The conclusions are as follows:①It makes a comparative study on the present wastewater treatment plantoperation mode in small towns in China such as the traditional institution mode，thepublic water company mode，the BOT mode，the TOT mode and the trusteeship mode.It proposed joint operation modes for wastewater treatment plant operation mode insmall towns. The joint operation modes can join in management link， production linkand purchasing link. It divided into two modes: the wastewater treatment plant incounty operate the wastewater treatment plants in town，and the wastewater treatmentplants in town joint operation. The applicable economic condition was that the operationcost joined was lower than before. The applicable mechanism condition was that thewastewater treatment plant operators agreed to join. The applicable geographicalcondition was that the distances between the wastewater treatment plants were not toofar. The applicable technical condition was using technology suitable for wastewatertreatment plants in small towns. The operation mode has the remarkable economic,social and environmental benefits.②In view of the features that small scale，decentralization and great difficulty inoperation management, of the wastewater treatment plants in small towns，it used amanagement mode that one central plant managed the rest wastewater treatmentplants.The optimal selection of the central plant was the basic premise of improving thejoint operation system reliability and operation economic efficiency. To determine the central plant location，multi-objective model of locations for joint operation centerwastewater treatment plants in small towns was presented by considering costminimization and reliability maximization. After transforming multi-objectiveoptimization models into single-objective optimization models by primary objectmethod，the optimum locations scheme for central wastewater treatment plants wasfound out and the computation results verifies the models, and then develops thelocation systemof the central plant of joint operation wastewater treatment plants insmall towns （Acceptance no：2012R11S016715）.③It took four joint operation wastewater treatment plants in Three Gorgesreservoir area as a demonstration project, and applied central plant location software ofjoint operation wastewater treatment plants in small towns to locate central plant.Theresult showed that: when the time limit was120min, it recommended A plant as thecentral plant, while the total cost was191400yuan and the time arrived the farthest sonwastewater treatment plant was62min.When the time limit was60min, itrecommended B plant as the central plant, the total cost was230900yuan, the timearrived the farthest son wastewater treatment plant was53min. It should consider actualconditions, rationally selected limited time, ensure the stability and reliability of jointoperation wastewater treatment plants，while giving consideration to the lowest cost.④It investigated and analysed the conventional wastewater treatment plantsoperation mechanism, and used successful experience of wastewater treatment plants insmall towns in developed countries for reference，then made the daily operationmanagement object, accident risk alarm mechanism, daily management mechanism,operation technology security mechanism and risk emergency management measures.