准好氧填埋结构渗滤液COD_(Cr)衰减规律及模拟研究

Study on the Attenuation Rules and Fitted Equations for Chemical Oxygen Demand of Semi-aerobic Landfill Leachate

建立模拟准好氧填埋场和厌氧填埋场中试试验装置(装置规模1.0m×1.5m×1.8m),并以后者做对照,对渗滤液ρ(CODCr)进行27周监测(每1～2周测1次),研究模拟准好氧和厌氧填埋结构的不同层次空间和底部渗滤液ρ(CODCr)的时空变化规律及降解效果,对2种填埋结构渗滤液CODCr衰减规律原因及差异进行分析.结果表明,准好氧填埋结构空间渗滤液ρ(CODCr)层次差异明显,呈现下层>中层>上层的规律,3层渗滤液ρ(CODCr)在前7周衰减幅度最大,之后表现为小幅度波动下降最后趋于稳定;在27周的监测时间里,准好氧填埋场空间和底部渗滤液ρ(CODCr)一直远低于厌氧填埋场对应层位,基本没有出现厌氧填埋场CODCr累积的现象.对准好氧填埋场上、中、下层和底部渗滤液ρ(CODCr)的衰减规律进行数学拟合发现,27周的拟合曲线与实测数据曲线相关性较好,基本反映了CODCr的衰减规律.

Simulated semi-aerobic landfill equipment and anaerobic landfill equipment （CK） were installed with scale 1.0 m × 1.5 m × 1.8 m in order to investigate temporal and spatial change and degradation of leaehate CODCr, and to explore the mechanism of CODCr decrease and the difference shown in two equipments. CODCr concentration was monitored for 27 weeks and measured once every 1 - 2 weeks. The results showed that leachate CODCr in semi-aerobic landfill equipment varied with spatial distribution, and showed under-layer 〉 middle-layer 〉 upper-layer. In the three layers, leachate CODCr mass concentration significantly decreased in the first 7 weeks; after that, CODer mass concentration decreased with fluctuation and finally stabilized. During the whole monitoring period of 27 weeks, CODer mass concentrations of spatial and bottom leachate in semi-aerobic landfill equipment were much lower than that in anaerobic landfill equipment, and little CODCr accumulation that often occurs in anaerobic landfill equipment was found. The attenuation rules of the CODCr mass concentration in upper- layer, middle-layer, under-layer and bottom of semi-aerobic landfill leachate were fitted, and the result showed that, during the 27 weeks, the fitted curves were well correlated with the measured curves and revealed the attenuation rule of CODCr in the semi-aerobic landfill equipment.