Study On Performance Assessment System Of Energy Conservation And Emission Reduction In Municipal Wastewater Treatment Plants

A large number of municipal treatment plants have been installed in recent years in ourcountry, which have certainly reduced the pressure of environmental pollutions. But someplanlts occur abnormal status such as low load rate, high operation cost, frequent abnormalconditions, uncomplete sledge treatment and excessive concentrations of total nitrogen ortotal phosphorus in their effluent. Thus, it is necessary to rapidly carry out energyconservation and emission reduction in these plants. The result of the work of energyconservation and emission reduction needs to be assessed by a scientific assessment systemand method, but unfortunely up to day such a system and method have not been found out.In order to fill this blank, a performance assessment system of energy conservation andemission reduction for municipal treatment plants and its corresponding evaluation methodhave been pointed out in this paper through survey and theoretical analysis. Therefore, thisresearch has pratical value and important social economic significance.Based on related research at home and abroad, through analying relative data and fieldresearch, we definited the meaning of the performance assessment on energy conservationand emission reduction for municipal sewage treatment plants as the objective and fairevaluation on performance and behavior of the plant and its employees in terms of energysaving and emission reduction by using statistics and operational research methods withspecific indicators and standards at first. Secondly, we developed the selection principles ofthe evaluation indicators of the performance assessment system. Thirdly, according tocharacteristics of sewage treatment process and the evaluation screening principles, weinvestigated the plants in finance, business management, environmental management,learning and growth and other aspects, and5rule hierarchy indexes which are pollutantemissions, energy consumption, pharmaceutical cost and resource utilization, operation andmanagement and sustainability and16first grade indexes were filtered out with thebalanced scorecard method. Then, through statistical analysis of actual operating data, theweights of indexes were determined with expert consultation and analytic hierarchy processmethods. At last, through statistical analysis of actual operating data, after considering therelevant industry standards, technological level and related planning requirements ofmunicipal wastewater treatment industry, the average value and optimal value of thequantitative indexes which was used to evaluated the quantitative indexes were found out;scores of qualitative indexes are evaluated by converted them into quantitative indexes.According to the secondary indicator scores, by using the weighted sum method, it can be derived the first grade indexes scores, and then the plant energy conservation and emissionreduction performance score of the plant, and also the class of the plant can be determinedwith the performance classification standard. At the end of this paper, the performanceassessment system and its corresponding evaluation method have been applied to assessthree plants in Guangdong. The result of the actual assessment is in conformity with actualsatuation of each plant. This shows the system and the method has good practical value,which can be applied to assess a sewage treatment plant on performance of energyconservation and emission reduction.