渗滤液在填埋场土层中运移规律及控制方法研究

Study on migration rules and controlling means of leachate in landfill soil

以中国徐州某垃圾填埋场为工程背景,在现场测试和室内模拟测试的基础上,利用GeoStudio数值模拟软件对生活源污染质在垃圾填埋场中的运移进行了模拟,研究了渗滤液在压实黏土层中运移的时空变化规律,并揭示了运移机理,为研究生活源污染质在土层中运移的控制方法提供了理论依据。研究结果表明,非饱和压实黏土层的土-水特征曲线可分为平缓下降、快速下降和平缓稳定三个阶段;渗滤液在填埋场中的运移过程分为压实黏土层有效和压实黏土层失效两个主要阶段,且分界点为10年;随着运移时间的推移,渗滤液中溶质浓度的增长速度逐渐降低;可通过提高填埋场防渗层的防渗能力和排水系统的导排能力、增加垃圾体的坡度和对生活垃圾进行分类等方法控制生活源污染质在压实黏土层中的运移。

Based on the field test and indoor simulation test of a landfill in Xuzhou, China, the migration of municipal waste contamination was simulated by using GeoStudio numerical simulation software. The temporal and spatial variation of leachate migration in compacted clay was studied and its migration mechanism was revealed, which provided a theoretical basis for the study of the control methods of municipal waste contamination migration in clay. The results indicated that the soil-water characteristic curve of unsaturated and compacted clay layer could be divided into three stages:gentle decline, rapid decline and gentle stability. The migration process of leachate in the landfill could be divided into two main stages: effectiveness of compacted clay layer and ineffectiveness of compacted clay layer, and the boundary point was 10 years. With the process of migration, the growth rate of leachate concentration decreased gradually. The migration of municipal waste contamination in the compacted clay layer could be controlled by improving the impervious capacity of impervious layer and the drainage capacity of the drainage system, increasing the slope of the municipal waste contamination and classifying the municipal waste.