Physicochemical Properties And Greenhouse Gas Emissions Characteristics Of Classified Municipal Solid Waste In Different Districts Of Ningbo City

With the rapid development of urbanization in China,the generation of municipal solid waste(MSW)is increasing,the phenomenon of "siege of garbage" is becoming more and more serious.The MSW not only limits the development of the city but also endangers the environment.Therefore,studying the characteristics of MSW is of great significance for the rational disposal and resource utilization of MSW.In order to formulate a reasonable treatment and disposal plan for classified MSW based on the nature of MSW,this paper takes Ningbo city as an example,the physical-chemical characteristics of classified MSW and the waste of kitchen waste treatment plant,incineration plant and landfill treatment were studied.The results showed that the proportion(%)of kitchen waste,paper,rubber and plastic in the MSW were 50.63,20.92 and 15.70,respectively,with an average bulk density of 145.1 kg/m3 and an average wet base calorific value of 8050 kJ/kg.The kitchen and fruit waste accounted for 77.34%in agricultural market,63.85%in kitchen waste treatment plant,58.17%in the incineration plant and 58.19%in the landfill were,with a bulk density of 205,250,269,and 268 kg/m3,respectively.The kitchen and fruit waste proportion was lower in spring and higher in summer,lower in Yinzhou district and higher in Haishu district.It had average water content of 68.95%,C/N 18.16,crude protein content 13.41%,starch content 9.08%,and crude fat content 9.33%.These results indicate that it is useful to classify municipal solid wastes,as the kitchen waste is suitable for biochemical treatments,whereas the remaining MSW is more adequate for incineration.In order to improve the classification level,it is suggested that Ningbo Municipal Government standardize the classification and collection system for MSW,and adopt an effective measures to promote MSW classification.Based on the actual situation of Ningbo City and combining with the methods recommended by IPCC and the guidelines for compiling provincial GHG inventory in China,the greenhouse gas emissions from major waste disposal treatments in Ningbo were calculated through experimentally measured data of relevant activity levels.The results showed that the maximum amount of greenhouse gas emissions from waste treatment was landfilling with 0.43 t CO2/t MSW,followed by incineration with 0.20t CO2/t MSW,the least was composting.On this basis,we calculated the greenhouse gas emissions from incineration and landfill in Ningbo from 2006 to 2016,and found that the emission of greenhouse gas emitted from incineration and landfill increased gradually and gradually decreased afterwards.In the recent two years,the amount of incineration higher than landfill,but incineration still produced less greenhouse gas than landfill.