城市垃圾卫生填埋场粘性土衬垫的截污容量及其研究意义

Filtration Capability of Clayey Soil Liner for Garbage Sanitary Burial Fields and Its Significance

垃圾卫生填埋法的关键技术之一是防渗垫层的铺设,国内外对防渗垫层的要求是“防渗”,所设计的防渗垫层所用材料种类多、价格贵、铺设复杂、成本高。若把垫层铺设的指导思想改为“截污”,可充分利用对垃圾污染质具有净化或阻隔能力的场地粘性土,降低垫层铺设成本。“截污容量”是基于这种思想提出来的、用于表征粘性土的截污能力的物理参量,其科学和实用意义、试验测试及计算方法将在本文得到探讨。

One of the key techniques for garbage sanitary burial is the pavement of a liner, which is designed to prevent seepage. It is very expensive. If the aim of paving the liner is turned to ' filtration' , we can make full use of the purification or partition capability of the clayey soil to reduce the cost. The term 'filtration capability' is a physical parameter put forward to describe the capability of the clayey soil to cut off the pollutants based on the above idea. The following conclusions are arrived at through the study; (1) The filtration capability of the clayey soil can be obtained through experiments and by using some special calculation methods. (2) The more times of leaching of garbage infiltration fluids, the poorer the purification capability of the soil to the pollutants. Also, the purification capability of the soil to the pollutants rises with increasing soil density, and the filtration capability of the clayey soil is lowered with the increasing number of leaching. (3) In the Shijiazhuang area, the purification or partition capability increases rapidly before the soil density reaches a certain value (1. 936 g/cm3) , but obviously slower after reaching the value. This result is of very important application significance in engineering projects. (4) In the soil columns of different densities of the same type of soil, there seems to be a trend of lowering of filtration capability with the increase of soil density.