轻非水相液体在不同粒径多孔介质中的运移与分布特性

Experimental investigation of migration and distribution characteristics of LNAPL contaminants in porous media of different particle sizes

通过二维砂槽模型模拟柴油在不同粒径多孔介质中运移与分布试验,由图像分析法获取油流锋面及其二维空间分布图,探讨其在不同粒径多孔介质中的迁移与分布特性。试验表明:轻非水相液体的入渗速度与方向受毛细水分和介质粒径的大小影响,也受介质的接触面及结构裂隙的影响;它随地下水位波动而重新分布;其在毛细区和粒径越小的介质中,残留现象越明显,污染越严重。研究它的迁移与分布规律,对于防治地下水和土壤污染有着重要的意义。

Through the experimental imitating diesel＇s migration and distribution in porous media of different particle sizes in a 2-D sand tank model, the oil flow fronts and 2-D spatial distribution are achieved with the image analysis method, and the migration and distribution characteristics of LN APL in porous media of different particle sizes are examined. The test shows that the infiltration velocity and direction of LNAPL are impacted by the capillary moisture and the medium particle size, as well as the contact surface of the dielectric and structural cracks. LNAPL will redistribute with the fluctuations of groundwater level. The more small medium of particle size and capillary area where LNAPL is in, the more obvious residual phenomenon, and the more serious pollution is. The study of migration and distribution pattern of LNAPL has important on the prevention and treatment of groundwater and soil contamination.