基于孔隙网络模型的表面活性剂去除LNAPLs作用力分析  

Force analysis of light non-aqueous phase liquids removal during surfactant-related floods in a porous network model

作　　者：杨建[1] 陈家军[1] 李合莲[1] 解建波[1] 

机构地区：[1]环境模拟与污染控制国家重点实验室,北京师范大学环境学院,北京100875

出　　处：《环境科学学报》2009年第8期1684-1689,共6页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金项目(No. 40772148)~~

摘　　要：通过多孔介质网络模型试验,并采用可视化技术研究了可溶相液体注入条件下轻质非水相污染物(Light non-aqueous phase liquids,LNAPLs)去除过程中多孔介质孔隙内毛细力和粘滞力的作用机理.实验和理论分析发现,可溶相液体去除孔隙内正十六烷在第一阶段(0～17823s)去除率为40%～50%,第二阶段(17823s之后)去除率为80%～95%,即正十六烷残余饱和度5%～20%;Triton X-100溶液可以大大降低多孔介质孔隙中LNAPLs的残余饱和度,最终正十六烷残留量为4.4%,是蒸馏水注入过程中正十六烷残留量的22.3%.蒸馏水注入过程中的毛细力比1100mg·L-1 Triton X-100溶液驱替NAPLs的毛细力大1个数量级,使得该毛细数位于毛细指进区(logNCa∈10-4),多孔介质内所有滞留的NAPLs保持静止.多孔介质内NAPLs主要被驱替去除;毛细数小的蒸馏水注入条件下,更多的NAPLs滞留在孔隙内;注入液在孔隙内流动溶解了部分NAPLs,导致NAPLs残余饱和度小于孔隙内由于毛细作用滞留的NAPLs初始饱和度.Mechanisms of light non-aqueous phase liquids （LNAPLs） removal during surfactant flooding were studied using a model with a visible porous network. Viscous forces and capillary forces acting on n-hexadecane were analyzed to reveal the LNAPLs removal mechanisms. The experimental and theoretical analyses show that 40% - 50% n-hexadecane was removed in the first stage （0 - 17823 s）, and residual saturation of n-hexadecane reached 5% - 20% in the second stage （ 17823 - 59008 s）. Flooding with Triton X-100 solution reduced the residual saturation of n-hexadecane to 4.4% , which was 22.3% of the residual saturation of n-hexadecane after distilled water injection. The capillary force during distilled water injection was one order of magnitude larger than that during 1100 mg·L^-1 Triton X-100 displacement of NAPLs. The capillary number of distilled water displacing NAPLs was within the capillary fingering domain （logNCa∈ 10^-4）, so residual NAPLs remained immobile in the porous media. Most NAPLs were displaced from the porous media by the displacement phase. More NAPLs remained in the pores with lower capillary number during distilled water injection. The injecting phase dissolved some of the NAPLs as it flowed along the channels of the porous media, so capillary action reduced the residual NAPLs saturation below the initial saturation.

关 键 词：表面活性剂 网络模型 LNAPLS 粘滞力 毛细力 

分 类 号：X53[环境科学与工程—环境工程]