基于ERT的垃圾厌氧填埋初期的水分运移过程研究

水分监测是填埋场运行过程中必不可少的一个方面,考虑到现有监测方法不容易得到垃圾内部的水分分布情况,本文将高密度电阻率成像法(ERT)用于监测生活垃圾在厌氧填埋初期的水分分布和运移过程研究.通过建立室内厌氧填埋模拟柱,应用取样分析、时域反射传感器(TDR)、高密度电阻率成像等方法对生活垃圾在厌氧填埋条件下初期两个月的降解和水分变化过程进行了监测与研究.结果表明,试验期间生活垃圾处于好氧降解过渡至厌氧降解的阶段.随着垃圾的降解,含水量呈现增加的趋势,在第30d之后,柱体内部存在明显的水分运移现象.在柱体下部单元层中,高密度电阻率成像法得到的垃圾电阻率值与时域反射传感器(TDR)测得的体积含水量之间存在明显的对应关系.根据电阻率与体积含水量的拟合公式,得到了柱体下部单元的含水量分布和储存水量的变化过程.储存水量的变化过程与质量含水量计算得到的结果是一致的,两者之间的可决系数达到0.9488.以上研究结果充分说明,在厌氧填埋初期,高密度电阻率成像法可以用于监测垃圾堆体内的含水量分布和水分运移过程.

Process analysis of water migration in anaerobic landfill column based on ERT

Monitoring of water content is one of the most important aspects in the operations of landfill. Due to the difficulty in monitoring the distributions of water content by traditional methods, we applied the electrical resistivity tomography (ERT) to investigate the distributions of water content and processes of water migration in the initial periods after waste was landfilled. In this study, waste sampling test, time domain reflectometry and ERT were employed to monitor the degradation of waste and variations of water content in two months in an anaerobic landfill. The results showed that waste decayed from aerobic condition to anaerobic condition gradually. Water content increased with waste degradation, and water movement occurred in column 30 days later. There was a clear relationship between waste resistivity and volumetric water content in lower unit of the column. According to the fitting formula, distributions of water content and variations of water volume in lower unit were calculated. The variations of water volume was consistent with that calculated from gravimetric water content, with the coefficient of determination as high as 0.9488. These results revealed that ERT could be used to monitor distributions of water content and processes of water movement in initial periods after waste were landfilled.