粘土衬层压实度对农村垃圾填埋场防渗性能影响研究

Influence of compaction degree of clay liner on anti-seepage performance of rural landfill

为了解垃圾渗滤液在不同压实度粘土衬层中的迁移扩散规律,选取了铁门岗乡土样模拟农村垃圾填埋场粘土衬层、并选取稀释的城市垃圾填埋场渗滤液模拟农村垃圾渗滤液,采用室内土柱淋滤实验模拟渗滤液在衬层中渗透过程,分析了渗滤液在通过不同压实度土柱时的渗透能力与污染物的削减情况。结果表明:(1)粘土层压实密度与渗透系数呈负指数函数增长关系,压实度达到93%后,压实度对渗透系数影响较小。(2)粘土层对CODcr,NH—N的吸附效果随着压实度增大而增强。其中粘土层渗透系数与CODcr,NH—N渗出率呈负指数函数增长关系。上述结果为农村垃圾填埋场各类压实度的粘土衬层应用分析研究提供参考。

In order to understand the migration and diffusion of waste leachate in clay liners with different compaction degrees,soil samples from Tiemengang Village were selected to simulate rural landfill clay liners,and diluted municipal landfill leachate was selected to simulate rural waste leachate,and indoor soil column drenching experiments were used to simulate the permeation of leachate in the liner,and the permeation capacity of leachate and the reduction of pollutants when passing through soil columns with different compaction degrees were analyzed. The results showed that:(1)the compaction density of clay layer and the infiltration coefficient showed a negative exponential function growth relationship,and after the compaction degree reached 93%,the compaction degree had less influence on the infiltration coefficient.(2)The adsorption effect of clay layer on CODcr,NH—N increased with the increase of compaction degree. Among them,the permeability coefficient of clay layer showed a negative exponential function growth relationship with CODcr,NH—N leaching rate. The above results provided a reference for the analysis and research on the application of clay liners of various compaction levels in rural landfills.