近5年我国部分城市群生活垃圾特性

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

城市生活垃圾处理处置日益成为世界范围内一个普遍关注的问题,生活垃圾特性是终端处理方式选择的重要依据.从全国超30个城市共采集400余个生活垃圾样品,分析了垃圾的物理组成、污染物含量和热值等基础物化特性.并以深圳为例分析了采样时间和垃圾分类措施等对生活垃圾物化特性的影响.通过偏最小二乘法建立了垃圾组成与热值间的关联模型,并对模型进行了校验.结果表明,湿基中厨余类仍是垃圾中占比最高的组分,大多数样品的占比在40%~60%之间;可燃组成中橡塑类和纸类占比较高,分别在20%~30%和10%~20%之间;无机物占比通常不超过5%;垃圾含水率在50%~60%之间.2019年实施垃圾分类后生活垃圾中厨余类占比明显降低,橡塑类占比增加,其他组分变化不大,垃圾热值得到一定的提升.生活垃圾中S、Cl和N这3种污染元素的含量均在1%以下,其平均值规律为:N>Cl>S;垃圾样品中的Hg、As、Cr、Cd和Pb含量随组分及采样时间没有明显的变化规律,垃圾中Pb、Cr含量受到环境背景值的影响.模型分析发现橡塑类和垃圾水分是生活垃圾热值的主要影响变量,85.96%的样品实测值与预测值之间的偏差小于20%,建立的模型可以满足对垃圾热值进行预测的需要.

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.