准好氧填埋结构中氧气扩散数值模拟  

Numerical Simulation of the Diffusion of Oxygen in Semi-Aerobic Landfills

作　　者：丁世存[1,2] 黄启飞[1] 汪群慧[2] 王琪[1] 

机构地区：[1]中国环境科学研究院固体废物污染控制技术研究所,北京100012 [2]北京科技大学土木与环境工程学院,北京100083

出　　处：《环境科学研究》2008年第6期16-20,共5页Research of Environmental Sciences

基　　金：国家自然科学基金项目(50508042)

摘　　要：依据准好氧填埋的原理构建了填埋试验装置.对试验装置的φ(CH4),φ(CO2)和φ(O2)的动态变化进行了监测.在装填完成21周后,垃圾体进入产甲烷阶段,第27周时φ(CH4),φ(CO2)和φ(O2)的加权平均值分别为14.7%,18.6%和4.0%.在准好氧填埋结构中,空气通过渗滤液收集主管道和竖直导气管道在垃圾体中进行扩散,并在这些管道周围形成耗氧区域,在空气扩散不到的地方为厌氧区域.通过数学分析判断该装置内的耗氧区域,并对浓度等值线进行拟合,得到O2在纵剖面内呈双曲线分布,在垃圾体内呈双曲面分布,且φ(O2)呈顶部>底部>中部的状态.推导出了氧气水平方向的扩散方程,并得出装置的水平耗氧半径为94.2cm,约为导排管直径的23.5倍.分析得到纵剖面内的耗氧区域占93.6%,并得出耗氧区域的纵剖面方程和空间方程.An experimental installation was built based on the semi-aerobic landfilling theory, in which the concentrations of φ（CH4）, φ（CO2 ）, and φ（O2 ） were determined. The results showed that, after 21 weeks operation, the municipal solid waste was in the stage of methane generation, φ（CH4 ）, φ（CO2 ）, and φ（O2 ） reached 14.7%, 18.6%, and 4.0%, respectively, at 27 weeks. In this installation, oxygen diffused through the pipelines collecting leachate and the vertical gas pipelines, and produced an O2 depletion zone around these pipelines. According to mathematical analysis, the aerobic zone was defined, on which a contour line of O2 concentration was fitted. The results indicated that O2 concentration showed a hyperbola in longitudinal profile and was higher in the upper zone than in the medium and bottom zones. In addition, the oxygen diffusion equation in the horizontal direction was deduced; the radius of oxygen depletion in the horizontal level was 94.2 era, and was about 23.5 times the radius of the longitudinal gas pipeline. The percentage of O2 depletion zone in the longitudinal profile was 93.6 % . Also, the equation of O2 depletion zone in the longitudinal direction and in spatial scale was obtained.

关 键 词：准好氧填埋 填埋气 氧气浓度 耗氧半径 模型 

分 类 号：X169[环境科学与工程—环境科学]