考虑非均衡吸附的多孔介质中循环注入污染物运移规律

发布时间：2018-06-15 03:25

本文选题：污染物运移 + 循环注入　；参考：《岩土工程学报》2017年07期

【摘要】：由经典的吸附解吸作用下污染物运移控制方程出发,将Freundlich线性等温吸附模型中溶质浓度上升、下降过程视为吸附、解吸过程,从而建立了非均衡吸附问题理论模型;并给出了累计质量分数及相对浓度的相关表达。利用Comsol Multiphysics数值分析方法讨论了三角函数、高斯脉冲函数循环注入下污染物运移规律,结果表明:吸附、解吸平衡常数的差值对污染物吸附量有较大影响,其值越大吸附量则越大;随着弥散度的增大,穿透曲线峰值有先增大后减小趋势,且穿透过程越久。此外,对于连续注入,注入时间存在一个临界值,小于该值时溶质浓度峰值随注入时间的增大而增大,而大于该值时溶质浓度峰值恒等于注入浓度平均值;且注入时间越大峰值出现时刻越晚;而相对浓度随注入时间的增大而减小。
[Abstract]:Based on the control equation of pollutant transport under the classical adsorption and desorption, the concentration of solute in Freundlich linear isothermal adsorption model is considered as adsorption and desorption process, and the theoretical model of disequilibrium adsorption problem is established. The correlation expressions of cumulative mass fraction and relative concentration are also given. By using Comsol Multiphysics numerical analysis method, the pollutant transport law under cyclic injection of trigonometric function and Gao Si pulse function is discussed. The results show that the difference between adsorption and desorption equilibrium constant has great influence on the adsorption capacity of pollutants. With the increase of the dispersion, the peak value of the penetration curve increases first and then decreases, and the longer the penetration process is, the larger the adsorption capacity is. In addition, for continuous injection, there is a critical value for injection time, and the peak value of solute concentration increases with the increase of injection time when the injection time is smaller, but the peak value of solute concentration is always equal to the average value of injection concentration when the injection time is greater than this value. The larger the injection time is, the later the peak appears and the relative concentration decreases with the increase of injection time.
【作者单位】：北京交通大学土木建筑工程学院;
【基金】：国家自然科学基金项目(51678043,51478034)
【分类号】：X141

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