论文部分内容阅读
该文考虑弥散尺度效应,建立了有限土柱中溶质运移的两点吸附降解模型。采用Laplace变换和数值反演方法求得了模型的半解析解,并应用试验资料对模型进行了验证。应用半解析解模拟分析了弥散尺度效应、平衡吸附点位所占比例及边界条件对溶质运移过程的影响。结果表明:弥散尺度效应越强土壤溶质运移锋面越远,分布范围越广,溶质浓度峰值越小。平衡吸附点位所占比例越小溶质运移锋面越远,但对溶质分布范围与浓度峰值影响不大。当经验常数a为1.0 m-1时,有限土柱和半无限土柱中溶质浓度几乎一致,出口附近处有限土柱中浓度模拟结果较高;当经验常数a小于1.0 m-1时,模拟结果恰好相反。
In this paper, considering the effect of dispersion scale, a two-point adsorption and degradation model of solute transport in a finite soil column is established. Laplace transform and numerical inversion method are used to obtain the semi-analytical solution of the model. The experimental data are used to verify the model. The effect of diffusion scale effect, the proportion of equilibrium adsorption sites and the boundary conditions on the solute transport were analyzed by semi-analytical solution modeling. The results show that the stronger the dispersion scale effect is, the longer the solute transport front of soil is. The wider the distribution range is, the smaller the peak of solute concentration is. The smaller the proportion of equilibrium adsorption sites, the farther the solute transport front, but the influence of solute distribution range and concentration peak is not significant. When the empirical constant a is 1.0 m-1, the solute concentration in the finite soil column and the semi-infinite soil column are almost the same, and the simulation results of the concentration in the finite soil column near the outlet are higher. When the empirical constant a is less than 1.0 m-1, the simulation The opposite is true.