Investigation And Analysis On Production And Discharge Of Municipal Solid Waste In Hefei City

With the rapid economic development,the output of municipal solid waste is increasing day by day,which brings many problems to the management and treatment of municipal solid waste.Taking Hefei city,the sub-center of the Yangtze River Delta urban agglomeration with rapid economic growth,as an example,this study constructed an investigation method for the characteristics of the production and discharge of municipal solid waste.The investigation and analysis were carried out from three aspects of history,current situation and future,and the following contents were obtained:(1)Investigation and analysis of the historical production and discharge of municipal solid waste in Hefei city.Literature research method,field visit method and government website query method are used to investigate the characteristics of historical production and discharge,and the influencing factors are screened based on chart analysis method,gray correlation analysis method and simple average grouping method.The results show that by 2020,The output of municipal solid waste in Hefei increased from 758,200 tons in 2011 to 1,889,700 tons in 2020,maintaining a growing trend with an average annual growth rate of 11.15%.The harmless treatment of municipal solid waste was incineration,landfill and composting,and the harmless rate reaches 100%.The six main influencing factors of municipal solid waste output in Hefei were resident population,total retail goods,gross domestic product(GDP),annual per capita disposable income,total value of tertiary industry and annual per capita consumption expenditure,and the comprehensive correlation of municipal solid waste output of the six influencing factors decreases successively.(2)Investigation and analysis of current production and discharge of municipal solid waste in Hefei.By means of the dominant symbol method and geographic information system(Arc GIS),the functional zoning and point discharge of the city were carried out.Combined with the on-site investigation,the current production and discharge characteristics of urban household garbage were investigated and analyzed,and the output of urban household garbage was 2,097,500 tons in Hefei in 2021.Shushan district accounted for 35.05%,Baohe 23.71%,Yaohai 22.88%,Luyang18.36%;In the functional area,residential area accounts for 45.61%,commercial area23.15%,industrial area 14.39%,development zone 10.76%,tourism and leisure area4.53%,urban-rural transition area 1.56%.Need "one area one policy" to achieve the reasonable allocation of resources.By 2021,Hefei has a total of 17 garbage transfer stations with a daily transfer capacity of 4010-5310 tons,and 8 harmless treatment plants with incineration and composting as the treatment methods,with a maximum daily treatment capacity of 10,900 tons,basically meeting the transport and treatment needs of Hefei.(3)Forecast and analysis of future municipal solid waste output in Hefei,Six single models including growth rate method(GRM),unary linear regression model(SLR),time series model(ARIMA),multiple linear regression model(MLR),grey system GM(1,1)model and back propagation neural network model(BPNN)were selected to fit and forecast the historical output of municipal solid waste.The mean absolute percentage error(MAPE),sum of square error(SSE),root mean square error(RMSE)and normalized root mean square error(NRMSE)were selected to test the model,and the weighted average grouping method and the induced ordered weighted harmonic average(IOWHA)operator were introduced to construct two combined models to optimize the model.Through the accuracy test,the model with the highest accuracy was selected to predict the future municipal solid waste output.It was found that among the six single models,MLR model and ARIMA model had higher accuracy than other models,and MLR model had the highest accuracy,with MAPE,SSE,RMSE and NRMSE being 1.28%,30.89,1.76 and 0.014,respectively.The MLR-ARIMA and MLR-ARIMA-IOWHA combined model constructed in this study,through precision test,the four precision indexes are 1.17%,27.03,1.64 and 0.013,respectively,after introducing IOWHA operator,the fitting prediction accuracy of the model can be improved.Based on MLR-ARIMA-IOWHA model,the output of municipal solid waste in Hefei from 2022 to 2025 and 2030 is predicted,and the output of municipal solid waste in Hefei from 2022 to 2025 and 2030 is 231.96 million tons,248.01 million tons,263.90 million tons,279.61 million tons and 355.48 million tons respectively.According to the prediction results,it was suggested to add 5 transfer stations and 2harmless chemical treatment plants in Hefei in the future.Based on the investigation and analysis of the production and discharge characteristics of municipal solid waste in Hefei city,the investigation method of the production and discharge characteristics of municipal solid waste is formed,which provides scientific basis for the management and treatment of municipal solid waste.