煤矸石淋滤液中污染物在GCL中的扩散性能

Diffusion ability of contaminants of coal gangue leachate in geosynthetic clay liners

为验证土工合成黏土衬垫(Geosynthetic Clay Liners,GCL)作为煤矸石处置场衬垫层建设材料的可行性,采用垂直式双筒扩散装置进行室内扩散试验,研究了煤矸石淋滤液中典型污染物Zn^2+、Mn^2+和SO4^2–在人工钠化膨润土GCL中的扩散性能,使用有限层法模拟软件POLLUTE V7对污染物随时间变化的曲线进行拟合,确定3种污染物在人工钠化膨润土GCL中的扩散系数。研究结果表明,污染物在GCL中的扩散系数低于它们在传统压实黏土衬垫层中的扩散系数,从而能更有效地控制煤矸石淋滤液中污染物在GCL中的扩散迁移行为。

To verify the feasibility of geosynthetic clay liners(GCL)as liners material for coal gangue impound-ment,diffusion tests were conducted with vertical double reservoir method to determine the diffusion ability of heavy metals(Zn^2+、Mn^2+)and sulfate from coal gangue leachate in GCL-S(Sodium-activated bentonite),and POLLUTE V7 based on finite layer method was used to draw the fitting curve of pollutant changing with time in the diffusion device,which calculated the diffusion coefficient of contaminants in GCL.The data show that the diffusion coefficient in GCL was lower than that in compacted clay liners,so GCL could control the diffusion and migration of pollutants more effectively.