Research On Comprehensive Evaluation Index System And Method In Printing And Dyeing Wastewater Treatment Facilities

The printing and dyeing industry has been playing an important role in theeconomical development of our country in the recent years. However, it is also an heavypollution industry. And recently, there are a large number of facilities treating the printingand dyeing wastewater in our country. But the construction of a scientific and rationalsystem for a comprehensive evaluation of related facilities is still in demand, because it isnecessary to know and monitor the current situation of those treating facilities which arein operation.The processing system of the treatment for the printing and dyeing wastewater is acomplicated process involving kinds of factors, such as economy, technology, operating,society, environment and so on. Based on the theoretical analysis, this article analysisedthe influencing factors of the related treating facilities and filtered nineteen indexes for theconstruction of a comprehensive index evaluation system of the equipments, which ispractical, objective and in line with the national condition of our country. The systemtakes comprehensive evaluation for the printing and dyeing wastewater treatingtechnology as the target layer,and the four aspects of economic, technologic,operatingmanagemental,environmental and ecological performance as the criterion layer.Among these aspects, the economical performance contains the indexes of unitconstruction investment,unit operating costs, and unit covering area; The technologicalperformance contains ten indexes including shock load capability, effluent COD, effluentBOD5, effluent SS, effluent color and PH, COD removal efficiency, BOD5removalefficiency, SS removal efficiency and color removal efficiency; The operatingmanagemental performance contains two indexes including the operability extent andclaims of personnel quality; The environmental and ecological performance includes offour indexes contains energy consumption level, excess sludge production, fresh wateron sumption level and degree of air pollution. Calculation of the weights of factors ofcriterion and indexes of index layers in the comprehensive evaluation system were carriedon followed by, which was based on the fuzzy analytic hierarchy process. It shows thatthe weights from the four factors of the criterion to the targets layer were0.2686,0.3090, 0.1972and0.2252respectively. At the same moment, the article has also calculated theweights of indexes compared with the factors under the criterion layer.At last, the comprehensive evaluation model of the printing and dyeing wastewatertreatment based on fuzzy analytic hierarchy process was constructed, and used in twofacilities already running for practical demonstration. It is apparent that the running stateof dyeing wastewater treatment facilities A was general, and B was good. Somesuggestions were given for the renovation and expansion of the facilities trough theevaluation process, such as “the printing and dyeing treatment should focus on the theconfiguration of the automation facilities to improve the the simplicity of the operationmanagement”.Our research indicated that the building of the model is scientific, and the model hascertain degree of practicality,which can provide a new idea for the comprehensiveevaluation of printing and dyeing wastewater treatment facilities.