多孔介质中轻非水相流体溶解迁移的数值模拟  

Numerical simulation of dissolution and transport of LNAPL in porous media

作　　者：侯岳岚 程亚平[1,2] 夏源 HOU Yuelan;CHENG Yaping;XIA Yuan(College of Environmental Science and Engineering,Guilin University of Technology,Guilin 541004,China;Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area,Guilin 541006,China)

机构地区：[1]桂林理工大学环境科学与工程学院,广西桂林541004 [2]岩溶地区水污染控制与用水安全保障协同创新中心,广西桂林541006

出　　处：《武汉大学学报(工学版)》2025年第1期39-44,共6页Engineering Journal of Wuhan University

基　　金：国家自然科学基金资助项目(编号:51978188);广西科技计划项目(编号:2019GXNSFDA245030)。

摘　　要：轻非水相流体(light non-aqueous phase liquid,LNAPL)向地下环境泄漏后,会在潜水面附近形成复杂的污染源,其溶解及迁移规律复杂。为确定LNAPL污染源在多孔介质中溶解迁移的过程,构建了LNAPL泄漏下渗污染多孔介质中地下水的理想算例,并采用TOUGH2软件对算例进行计算,对不同泄漏速率和水位波动条件对溶解过程的影响进行了讨论。模拟显示,LNAPL污染物下渗到潜水面后,将形成油膜状污染源,其形态和位置随时间改变,穿透曲线表现为快出峰、慢回落、尾部下跌。溶解相迁移快且在相分布中占比较多,对环境危害最大。高泄漏速率将增加溶出的总质量,使穿透曲线出峰时间提前、峰值更高,但后期影响不明显。水位上下波动将使残留在包气带的LNAPL被驱替和部分溶出,使得溶出总质量更多、穿透曲线的峰值更高、后期拖尾更明显。After the leakage of light non-aqueous phase fluid(LNAPL)to the underground environment,complex pollution sources are formed near the water table,and the dissolution and migration rules are complex.To determine the dissolution and migration processes of LNAPL pollution sources in porous media,an ideal example of groundwater infiltration contaminated with porous media under LNAPL leakage is constructed and calculated by using TOUGH2 software.The effects of different leakage rates and water level fluctuation on the dissolution process are discussed.The simulation shows that after LNAPL pollutants seep down to the water table,an"oil film"-shaped pollution source is formed.Its shape and position will change with time,and the breakthrough curve is"fast peaking,slow falling and tail dropping".The dissolved phase migrates quickly and occupies a relatively large proportion in the phase distribution,which is the most harmful to the environment.High leakage rates will increase the total mass of dissolution,making the breakthrough curve peak out earlier and higher,which is not obvious in the late period.The fluctuation of water table will make the LNAPL remaining in the vadose zone be displaced and partially dissolved,resulting in a higher total dissolved mass,a higher peak value of the penetration curve,and a more obvious tail in the later period.

关 键 词：LNAPL 地下水污染 石油烃 数值模拟 

分 类 号：P641.69[天文地球—地质矿产勘探]