燃油污染对多孔介质水文地质参数的影响研究  

Influence of Fuel Pollution on Hydrogeological Parameters of Porous Media

作　　者：杨鹏飞 陈余道[1] 蒋亚萍[1,2] 闫嘉宁 郑杲 邹志坤 刘权 覃佳肖 YANG Pengfei;CHEN Yudao;JIANG Yaping;YAN Jianing;ZHENG Gao;ZOU Zhikun;LIU Quan;QIN Jiaxiao(Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area,Guilin University of Technology,Guilin 541004,China;Technical Innovation Center of Mine Geological Environmental Restoration Engineering in Southern Karst Area,Nanning 530031,China)

机构地区：[1]桂林理工大学岩,溶地区水污染控制与用水安全保障协同创新中心,桂林541004 [2]自然资源部南方石山地区矿山地质环境修复工程技术创新中心,南宁530031

出　　处：《高校地质学报》2023年第4期608-616,共9页Geological Journal of China Universities

基　　金：国家自然科学基金项目(41967028);广西自然科学基金重点项目(2019GXNSFDA245030)联合资助。

摘　　要：燃油污染对地下水环境造成的影响不容忽视,调查污染场地的水文地质参数,有助于更好地认识污染前后水文地质参数的变化,以及污染物在地下水中迁移行为的变化。文章通过3个阶段的定量示踪实验,对实验室砂槽开展了污染前和污染后水文地质参数估测,对比了汽油污染前后参数的差异,评价汽油污染对水文地质参数的影响。结果表明:(1)汽油污染的积累会导致生物堵塞发生,生物堵塞程度随着渗流距离的增加有减缓趋势;多孔介质中不同区域溶质弥散作用存在差异,中央线上优势流的溶质通量增加,质量回收率提高;溶质穿透曲线峰型呈现瘦高型,并出现明显的拖尾。(2)通过监测长达6年的汽油污染实验,传统汽油砂槽(TG-tank)和乙醇汽油砂槽(EG-tank)的渗透系数分别为25.4、20.5 m/d,降低为砂槽被污染前初始渗透系数K_Ⅱ的61%、49%;TG-tank和EG-tank的有效孔隙度由初始值0.30分别减小为0.28、0.26;与未污染时比,污染后水动力弥散系数也会减小。乙醇汽油污染对多孔介质渗透性的削弱更显著,有机污染的积累会改变污染场地的水文地质参数,加强污染后水文地质参数的估测,能够为评价污染风险提供合理依据。Influence of fuel pollution on groundwater environment is an important subject.Investigating the hydrogeological parameters of contaminated sites will be helpful to understand the changes of hydrogeological parameters before and after pollution,as well as changes of the migration behavior of contaminants in groundwater.To compare the differences of parameters before and after gasoline contamination and evaluate the impacts of gasoline contamination on hydrogeological parameters,three stages of quantitative tracer experiments in sand-tank were performed.The results show that:(1)the accumulation of gasoline contamination leads to the occurrence of bioclogging,and the degree of bioclogging tends to slow down with the increasing percolation distance;there exist differences in solute dispersion in different regions of porous media,and increased solute flux in the dominant flow on the central line and the mass recovery rate;the solute Breakthrough Curves show a lean-high pattern and a clear trailing.(2)by monitoring the gasoline contamination for 6 years,it is found that the permeability coefficients of traditional gasoline tank(TG-tank)and ethanol gasoline tank(EG-tank)were 25.4 and 20.5 m/d,respectively,which decreased to 61%and 49%of the initial permeability coefficient KII before the sand tank was contaminated;the effective porosity of TG-tank and EGtank was reduced from the initial value of 0.30 to 0.28 and 0.26,respectively.Hydrodynamic dispersion coefficient also tended to decrease.The permeability of porous media is reduced more significantly by ethanol gasoline pollution.The accumulation of organic contamination will change the hydrogeological parameters of the contaminated site,and strengthening studies of hydrogeological parameters after contamination can provide a reasonable basis for evaluating the contamination risk.

关 键 词：水文地质参数 生物堵塞 地下水污染 LNAPL 时间矩 示踪实验 

分 类 号：P641[天文地球—地质矿产勘探]