垃圾填埋场运行过程中,渗滤液的渗流和生物化学作用,不断影响和改变着排水层的渗透性能.以不同粒度成分的砂砾排水层为研究对象,模拟填埋场渗滤液的渗流,探索性地将化学实验方法应用于渗滤液排水层渗透能力评价中.实验发现,渗滤液中挥发性脂肪酸的发酵产物(碳酸)与金属离子发生化学反应是淤堵物生成的主要原因,而生物膜的生长和固体悬浮物的沉聚是次要原因.淤堵物的主要化合物成分是碳酸钙和二氧化硅,主要元素组成为Ca、Si、Fe、Mn、Zn、Mg等.淤堵物的成分及其相对含量与排水介质粒度成分无关,但排水介质的有效粒径越大,生成淤堵物的总量越多.建立了排水层渗透性(K)与渗滤液水质(COD)、排水层结构(avρgl·d10和排水孔隙度)间关系的淤堵模型.
As landfill site working, biochemical process and seepage of leachate always affect and change drainage layer permeability. Considering sands and gravels drainage layer with different granulometric composition as research object and simulating leachate seeping in the MSW landfill, a method of chemical experiments was explored and used to evaluate the permeability behavior of drainage layer. It is the main reason for clogging matter formation that zymolytic production of volatile fatty acid, carbonic acid, reacted with metallic ion, whereas biomembrane growth and solid suspended sedimentation are secondary. Calcium carbonate and silicon dioxide are of major compounds of the clogging matter, and Ca, Si, Fe, Mn, Zn, Mg are of main elements ; The components and their relative contents of the clogging matter are independent of granulometric composition of the drainage medium, but the larger effective particle size is, the more generation gross is. Then an analog function, concerning the relationship among drainage layer permeability coefficient (k), leachate water quality(COD) and drainage layer fabric( avpgl . d10 and drainage porosity)is set up.