城市生活垃圾理化性质的动态特性分析

Dynamic Characteristics Analysis on Physical and Chemical Properties of Municipal Domestic Solid Waste

对太原市城市生活垃圾的组成、化学元素及重金属等进行了1年(每月2次)共24次的分析。结果表明,太原市生活垃圾的组成在焚烧过程中,能产生低位热值(Q低)的有机物占(44.28±2.24)％,不产生低位热值的无机物占(13.94±2.01)％,混合物(破碎的动植物碎片及粘附在其上面的灰、土、砂)占(43.36±8.67)％。垃圾中可燃物比例较高,水分含量较低,有利于焚烧和热解,低位热值(Q低)平均值为(5590.8±1252.3)kJ/kg,但低位热值随季节变化较大。垃圾中化学元素硫(S)、氯(Cl)、氮(N)、氢(H)、碳(C)、氧(O)的年平均值分别为(0.20±0.13)％、(0.48±0.11)％、(0.87±0.18)％、(2.56±0.76)％、(30.78±4.06)％、(16.42±5.17)％,与其他城市相比,S、N、Cl的含量较高。垃圾中的重金属铅(Pb)、镉(Cd)的年平均值分别为41.94mg/Kg和1.806mg/kg;汞(Hg)含量变化较大。焚烧后的灰渣中,Pb部分挥发,Cd得到富集,但几乎无Hg检出。

Based on the data of one year about the physical composition and chemical elements of municipal solid waste (MSW) in Taiyuan city, the paper dealt with the seasonal changes of characteristics of MSW. Among the physical composition, the combustible substances, which produce heat in incineration, accounted for 44.28 ± 2.24% and the non-combustible which did not produce heat in incineration, accounted for 13.94 ± 2.01%. The mixed material, including animal and plant debris as well as the dust fixed, accounted for 43.36 ± 8.67%. The water content was relative low in MSW and this is good for incineration. The low heat value of annual mean was about 5590.8±1252.3 kJ/kg in MSW, but the value changed greatly with the season. The value of chemical elements of S, Cl, N, H, C, O annual mean were 0.20 ± 0.13%, 0.48 ± 0.11%, 0.87 ± 0.18%, 2.56±0.76%, 30.78 ± 4.06%, 16.42 ± 5.17% respectively. The amount of S, N, Cl in MSW was higher compared with other cities in China. The annual mean amount of heavy metals Pb and Cd were 41.94 mg/kg and 1.806 mg/kg respectively in MSW. The amount of Hg changed greatly with the season in MSW. After incineration the amount of Pb in the ash decreased and Cd increased, but Hg almost could not be found.