关键词: 四氯乙烯, 裂隙介质, 迁移, 地下水流速, 裂隙面倾斜度

Abstract: Perchloroethylene (PCE) was selected as the representative dense non-aqueous phase liquid (DNAPL) to investigate its migration and distribution characteristics under different flow velocities and dip angles in single fractured media. By using the light transmission method, we could monitor the migration and saturation distribution of PCE dynamically, and therefore the change process of PCE source zone architecture could be characterized. The results showed that PCE separated from the injection needle in the form of lumps, and was nearly elliptical and not continuous with each other in the process of migration. In this paper, Fs refers to the square of the initial pollutant separated from the injection needle. The larger the flow velocity was, the larger Fs was, and the smaller PCE centrifugal rate e was; the larger the dip angle was, the smaller Fs was, and the smaller the centrifugal rate e was. When the infiltration process became stable, the area and centrifugal rate of agglomerated PCE decreased  significantly. The increase of flow velocity and dip angle promoted the vertical migration of PCE, which accelerated the front-end migration rate of PCE and made PCE move to the bottom of the fracture system more quickly. The increase of flow velocity promoted the distribution of PCE, and the peak saturation decreased, while the increase of dip angle suppressed the distribution and made the peak saturation increase during the process.

Key words: perchloroethylene, fractured media, migration, flow velocity, dip angle