Optimization Of Process Design Scheme For Sewage Treatment Plant Renovation Project

With the continuous improvement of Chinese sewage treatment standards,the old sewage treatment plants in many cities in China have been unable to meet the sewage treatment standards,so it is necessary to upgrade the old sewage treatment plants.Based on the analysis of the status quo of lugang sewage treatment plant,it is found that the designed water volume can no longer meet the actual requirements of the water intake,the effluent water quality does not meet the requirements of the environmental protection department,and there is no odor collection and treatment system in lugang sewage treatment plant.In view of these problems,a large number of studies have been carried out on the processes related to the pre-treatment,biochemical treatment,in-depth treatment and odor collection and treatment system of the upgrading project of sewage treatment plant,and three feasible upgrading technology schemes have been preliminarily determined as alternatives.In order to select the optimal scheme,establish a comprehensive evaluation index system for the process design scheme of upgrading wastewater treatment plants by the characteristics of the upgrading project of sewage treatment plant and the establishment method of the international common index system.According to system analysis and selection,the principle of index evaluation and expert evaluation method,finally determine technical performance,environmental impact,economic benefits and social effects,which are the primary indexes.Meanwhile,select 16 secondary indicators,including technical indicators,the effluent water quality situation,smell influence,energy consumption etc.Then,use the analytic hierarchy process to establish the hierarchical structure model for the three schemes.After that,the MATLAB software is used to calculate the expert evaluation value,and the weight of each index in the comprehensive evaluation system of the Lugang Sewage Treatment Project is obtained.Finally,the three schemes of the Lugang Wastewater Treatment Plant were upgraded by the expert scoring method.The total score of the scheme 1 is 8.1358,the scheme 2 is 7.8856,and the scheme 3 is 7.6315.Thus draw a conclusion: the scheme 1 is the optimal one.Through investment estimation and cost analysis,it is concluded that the total investment of the project is 185.51 million Chinese Yuan(CNY).The total cost of the estimated project is to be 92.09 million CNY per year,of which the operating cost is 76.83 million CNY per year,and the operating cost is 2.631 CNY per cubic meter.Scheme 1 will greatly decline the pollution of urban sewage to the water environment,and at the same time have significant social and economic benefits.Therefore,it is feasible and reasonable to construct the renovation project of Lugang Sewage Treatment Plant through Scheme 1.The establishment of the evaluation system can also provide theoretical reference for the optimization of the renovation scheme of the same type of sewage treatment plant.