地下水水位波动对石油污染物迁移及透镜体位置的影响

近年来石油类污染在土壤和地下水环境中日益严重，由于天然及人为因素导致的地下水水位波动会造成污染物的二次迁移，扩大污染范围，因此探究水位波动对污染物迁移的影响刻不容缓。以柴油为例，利用二维模拟槽模拟柴油在地下水水位波动带中的迁移情况，通过控制水位升降模拟地下水水位波动，研究柴油透镜体的位置、模拟槽内柴油-水-气体饱和度随水位波动的变化，分析地下水水位波动对石油类污染物在地下水非饱和带中迁移的影响。结果表明:当水位向下波动时，油相可驱替水向下迁移，透镜体位置下移，迁移的过程中部分油相被介质吸附形成残余相，导致残余相柴油的污染范围增大；而当水位向上波动时，水可驱替油相向上迁移，透镜体位置上移，迁移的过程中部分油相溶解，导致溶解相柴油的污染范围的增大。该研究可为实际污染场地的修复提供理论支撑。

EFFECT OF WATER-TABLE FLUCTUATION ON PETROLEUM POLLUTANT MIGRATION AND LENS POSITION

In the past few years, the pollution of soil and groundwater by petroleum pollutants became increasingly serious.The fluctuation of groundwater level caused by natural and man-made factors will cause the secondary migration of pollutants and expand the pollution scale.Therefore,the remediation of petroleum pollutants in water-table fluctuation zone have to be settled urgently. In this study, picking diesel as a representative of petroleum pollutants, the migration and transformation of diesel in water-table zone was simulated in a two-dimension sand box. The main purpose of this study were to research the change of diesel lens position, diesel-water-gas saturation in a two-dimension sand box in difference water level variation mode, and to analyze the effect of water-table fluctuation on the transport behavior of petroleum pollutants in unsaturated zone of groundwater. The results showed that when the water level fluctuated downward, the oil phase could drive the water to migrate downward, and the lens position moved downward. During the migration process, part of the oil phase was adsorbed by the medium to form a residual phase, resulting in an increase in the pollution range of the residual phase diesel; when the water level fluctuated upward, the water could drive the oil phase to move upward, and the lens body position moved upward. During the migration, part of the oil phase dissolves, which led to an increase in the pollution range of the dissolved phase diesel.This research could provide theoretical support for the remediation of actual contaminated sites.