地下水位波动对燃油泄漏源区BTEX溶解影响的数值模拟

Numerical simulation influence of groundwater level fluctuation on BTEX dissolution in fuel oil leakage source area

为研究水位波动对燃油泄漏源区BTEX的溶解量影响,开展了多孔介质含水砂槽汽油投注实验,投注物是含有溴化钾的传统汽油和乙醇汽油,并对BTEX浓度进行了分析检测。结合VisualMODFLOW软件中RT3D模块模拟了水位波动条件下的BTEX溶解量,并运用质量通量方法计算了源区断面在不同水位条件下质量通量的观测值与模拟值,对比验证了模型的合理性。结果表明:传统汽油投注一侧,模型内BTEX横向运移显著,且BTEX浓度较另一侧低;质量通量观测值与计算值相近,最大差值为10.7mg/L;通过水位稳定条件下BTEX污染物有效溶解度计算,可确定模型点源污染物投注流量为0.0036m^3/d,进一步校正后,得出在水位波动条件下源区BTEX的最大释放量为149.6mg/L,为有效溶解度的2.4倍。

In order to study the influence of water level fluctuation on BTEX dis-solution in the fuel oil leakage source area, a laboratory-scale experiment was conducted with an aquifer tank. The injections are traditional gasoline and ethanol gasoline containing potassium bromide, and the BTEX concentration was analyzed and tested. Combined with Visual MODFLOW software, RT3D module was used to simulate the dis-solution of BTEX under water level fluctuation condition.Mass flux method was used to calculate the observed mass flux and simulated mass flux at different water levels in the cross section of the source area, and compared to verify the rationality. The results showed that on the traditional gasoline injection side, BTEX lateral migration is significant in the model, and the concentration of BTEX in the pollution source area is lower than the other side. Mass flux observations and calculated values are similar, the maximum difference value is 10.7 mg/L. Through the calculation of the effective solubility of BTEX pollutants under water level stability, the injection flow of point source pollutants in this experimental model can be determined as 0.003 6 m^3/d. After simulated and corrected with substituting, it can be concluded that the maximum value of BTEX release in the source area of the sand model is 149.6mg/L under the water level fluctuation condition,2.4 times of the effective solubility.The research results can provide data reference for the treatment of real pollution sites.