不同降解阶段填埋垃圾体的气体渗透特性研究

Study on Gas Permeability of Compacted MSW under Different Decomposing Stage

通过对不同降解阶段填埋垃圾体渗透系数的测定,研究了在不同压实密度、不同含水率条件下垃圾体渗透特性的变化情况,实验表明:1 对不同降解阶段的填埋垃圾体,新鲜垃圾与混和垃圾的渗透系数接近,腐熟垃圾明显高于前两者;随压实密度增加,其气体渗透系数均呈指数规律递减;2 随着垃圾体含水率的增加,腐熟与新鲜垃圾的渗透系数均呈线性规律递减,含水率对渗透系数的影响要远小于压实密度的影响;3 新鲜垃圾、混合垃圾、腐熟垃圾均具有较显著的各向异性特征,在典型压实密度下,水平方向的气体渗透系数Kh为垂直方向渗透系数Kv的3.5～27.3倍。

?In this paper, a method for measuring gas permeability Kh,Kv of compacted MSW under different compacted densities and different water contents by a landfill lysimeter has been proposed. Gas permeability of compacted MSW in three decomposing stages (fresh MSW, halfdecomposed, and fulldecomposed)were studied by this method. The results indicate that gas permeability Kh,Kv decline with compacted density increment in exponential relation for all three decomposing stage MSW and decline with water content increase in linear relation for fresh and fulldecomposed MSW; Compacted MSW in three decomposing stages has typical feature of heterogeneous porous media. In typical compacted densities, gas permeability Kh in horizontal direction are 3.5～27.3 times of Kv in vertical direction (compacted direction);