城市生活垃圾卫生填埋场填土层工程特性及净化机理研究

ENGINEERING PROPERTIES AND DECONTAMINATION MECHANISM OF EARTH-FILL USED TO WASTE SANITARG DISPOSAL

城市生活垃圾卫生填埋场中，填土层对垃圾淋滤液的渗透阻滞和净化作用具有重要意义。对成都万兴固体废弃物处置场填土料的压实性、渗透性及其相互关系，在大量试验的基础上作了深入探讨并导出关系式。填土层对垃圾淋滤液中污染物的衰减净化，是各种因素综合作用的结果。以工程地质为基础，研究生活垃圾淋滤液中常见离子净化规律和机理，认为土层结构的不同，对淋滤液的净化有一定影响，而这种影响因离子的不同而有不同程度的表现：二价离子交换吸附，引起渗透系数在０．５～１．０个数量级范围内变化；离子的负吸附，表明土层吸附的可逆性；而典型的一价离子ＮＨ＋４和Ｃｌ－的净化规律，可用指数函数表征；有机物的衰减与土的有机碳的含量有关。这些研究成果，为全面研究填埋体结构的合理化设计提供了重要依据。

In the waste filling , it is extremely important that the earth-fill retards the percolation of the waste leached solution. In this paper, on the basis of a large number of test data, the compaction and permeability of earth-fill (Wanxing area ,Chengdu )and their relationship was discussed , the related expression of the permeability coefficient K to the compaction work P , water content W , dry density and so on was established . The attenuation and cleaning of leachate in the filled layers is affected by various related factors. Based on Engineering Geology, the paper presents the mechanism and laws of frequently-appeared irons in leachate. The results of earth-column tests indicate that the structure of layers has effects on the transport and cleaning of irons in different degree with different irons; that due to exchange adsorption of divalent cation (Ca 2+ ,Mg 2+ ) the permeability is changed in ( 0.5 ～ 1.0 )10 -rang;that there reversibility of adsorption is taking place in layers; that potential function of typical monovalent irons (NH + 4,Cl -) is exponential. Sorption of organic chemicals controlled by the amount of organic carbon is also discussed. Therefore ,an important basis was provided for comprehensive study of the rationalized design of waste landfill structure.