[Characteristics of Municipal Solid Waste in Some Urban Agglomeration in the Past Five Years]

The treatment and disposal of municipal solid waste has increasingly become a common concern around the world, and the characteristics of municipal solid waste(MSW) are an important basis for the selection of terminal treatment methods. In this study, more than 400 MSW samples from over 30 cities across China were collected, and the basic physical and chemical properties, such as the physical composition, pollutant content, and calorific value, were analyzed. Shenzhen was taken as an example to analyze the influence of time and waste sorting measures on the physical and chemical characteristics of MSW. The correlation model between MSW composition and calorific value was established using partial least squares(PLS) regression, and the model was verified. The results showed that with per capita GDP increasing by 10,000 yuan, per capita MSW production and the low calorific value of MSW increased by 0.1 kg·(person·d)^-1 and 373.8 kJ·kg^-1, respectively. However, when per capita GDP was less than 60,000 yuan, the correlation between per capita GDP and per capita MSW production was relatively poor. Kitchen waste was still the most abundant component of MSW, and the content of most samples was between 40% and 60%. The combustible content of rubber/plastic and paper was relatively high, between 20%-30% and 10%-20%, respectively. The inorganic content did not usually exceed 5%, and the moisture content of the MSW was between 50% and 60%. After the implementation of waste classification in 2019, the content of kitchen waste in MSW had been significantly reduced, the content of rubber/plastic had increased, and other components had not changed much. Additionally, the calorific value of waste had been improved to a certain extent. The pollution element contents in MSW, S Cl, and N were all below 1%, and the average value was:N>Cl>S. The contents of Hg, As, Cr, Cd, and Pb in MSW samples did not change significantly with the composition and sampling time, and the content of Pb and Cr in MSW was affected by the environmental background value. The model analysis revealed that rubber/plastics and moisture content were the main variables that affected the calorific value of MSW. The deviation between the measured value and the predicted value was less than 20% for 85.96% of the samples. The model established in this study can meet the needs of the prediction of the calorific value of MSW.