依据准好氧填埋工艺的原理建立了试验装置,在填埋进入相对稳定期后,测定填埋装置内各个采样点的填埋气体积分数φ(CH4)、φ(CO2)以及φ(O2),分析了采样点到中心导气管的距离对φ(O2)的影响,并采用数学模型进行拟合。结果表明,准好氧填埋进入相对稳定期后,由于装置内外温度差异以及氧气浓度的差异使氧气通过导排管进入装置内部,并呈现出上层〉下层〉中层的规律。在垃圾填埋体的好氧分解反应、硝化作用以及甲烷氧化作用的共同作用下,下层与中层φ(O2)与距离的关系呈现指数规律下降,上层由于结构的特殊性呈现抛物线形状。
According to theory of semi-aerobic landfill, lab scale installment was set up. During the steady stage of landfill process, the volume fraction of methane, carbon dioxide and oxygen were detected in different sampling points. The effect of distance between sampling point and central gas tube to the volume fraction of oxygen was analyzed and simulated with mathematic model. Results showed that in the steady stage of semi-landfill, volume fraction of oxygen in different layers showed certain trend because of oxygen diffusing which resulted from the difference of temperature and oxygen concentration between inside and outside installment. With the combined effect of aerobic decomposition reaction, nitrification and methane oxidation in pile, volume fraction of O2 in bottom layer and middle layer declined under exponential law and volume fraction of O2 in upper layer showed parabolic shape because of its special structure.