城市生活垃圾降解压缩试验仪研制及应用

为了研究城市生活垃圾降解与填埋场沉降关系问题,研制了一台垃圾降解压缩试验仪。该仪器具有温度控制、渗滤液回灌、加压、气体和液体收集等功能。5kg垃圾试样装入直径为190mm的土样室(试样初始高度为320mm),在150kPa压力下进行一维降解压缩试验。试验检验了温度、回灌、气压等因素对降解速率的影响程度。试验结果表明,温度是影响降解的主要因素,回灌能加快产气速率,在400kPa的气压下(绝对气压),降解仍能继续进行。在温度为41℃和回灌的条件下,6个月后降解已基本完成;气相色谱/质谱分析结果表明,气体组分主要为CH4、CO2和H2O。降解完成后,总的变形量为142mm,其中主压缩变形量为65mm,次压缩变形量为77mm。提出了在填埋场沉降计算时考虑气压影响的必要性。

Development and application of biodegradation-compression test apparatus for municipal solid waste

To study the relationship between the municipal solid waste biodegradation and the settlement of the landfill, a biodegradation-compression test apparatus for MSW was developed, whose functions include temperature controlling, leachate recirculating, loading and gas collecting. A sample of 5 kg refuse with the height of 320 mm, filled in a 190 mm diameter cylinder, was compressed under 150 kPa and decomposed under different conditions with various temperatures, gas pressure, and leachate recirculation .The test results showed that temperature was the dominant factor influencing the biodegradation rate, and lechate recirculation increased gas production rate. The refuse kept decomposing at 400 kPa (absolute gas pressure ). The biodegradation of the refuse sample nearly completed after 6 months, which was placed in a cylinder maintained 41℃ and operated with leachate recycled; The GC/MS analysis represented that the gas generated from the refuse was mainly composed of CH4, CO2 and H2O. The total deformation of the sample was 142 mm, among which the secondary compression deformation was 77 mm.The gas pressure should be considered to calculate the settlement for landfills.