摘要
为研究变弥散系数和对流速度对有机溶质在多孔介质中运移规律的影响,考虑有机溶质的降解作用,设定多孔介质的厚度为有限厚度,建立变弥散系数和对流速度下有机溶质一维运移的数学模型,并利用变量代换和分离变量法获得该数学模型的解析解。将本文所提解析解分别与试验测定结果、已有解析解和有限差分解进行对比分析,对所提解析解的正确性进行验证。基于所提解析解,分析非均质特性系数δ、降解半衰期t1/2和Robin边界常数α对有机溶质一维运移过程的影响。研究结果表明:一方面,非均质特性系数δ的增大会在一定程度上加快有机溶质的一维运移过程;另一方面,δ增大使得运移后期有机溶质的质量浓度减小;有机溶质质量浓度随降解半衰期t1/2增大而增大,当t1/2不超过800 a时,应考虑有机溶质的降解作用;Robin边界常数α主要影响出流边界附近有机溶质质量浓度的变化;在两种不同入流边界条件下,出流边界附近的有机溶质的质量浓度均随α增大而减小。
To investigate the effects of variable dispersion coefficient and variable advection velocity on the transport process of organic solutes in porous media,a mathematical model for one dimensional transport of organic solutes with variable dispersion coefficient and variable advection velocity was established,where the degradation of organic solutes was considered and the thickness of porous media was set as a finite thickness.The analytical solution for the mathematical model was obtained by using the methods of variable substitution and variable separation.By comparing the analytical solution proposed in this paper with the experimental results,the existing analytical solution as well as the finite difference solution,and the correctness of the proposed analytical solution was verified.Based on the proposed analytical solution,the effects of heterogeneous characteristic coefficientδ,degradation half-life t1/2 and Robin boundary constantαon the one-dimensional transport process of organic solutes were analyzed.The results show that on one hand,the increase of heterogeneous characteristic coefficientδwill accelerate the one dimensional transport process of organic solutes to a certain extent,and on the other hand,it will reduce the mass concentration of organic solutes in the later stage.The mass concentration of organic solutes will increase with the increase of degradation half-life t1/2.When t1/2 does not exceed 800 a,the degradation of organic solutes should be considered.The Robin boundary constantαmainly affects the variation of organic solutes mass concentration near the outflow boundary.Under two different inflow boundary conditions,the mass concentration of organic solutes near the outflow boundary will decrease with the increase ofα.
作者
江文豪
李江山
黄啸
程鑫
JIANG Wenhao;LI Jiangshan;HUANG Xiao;CHENG Xin(The State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;The University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Contaminated Sludge and Soil Science and Engineering of Hubei Province,Wuhan 430071,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2023年第4期1518-1530,共13页
Journal of Central South University:Science and Technology
基金
国家重点研发计划项目(2019YFC1804002)
国家自然科学基金资助项目(51625903,42177163)。
作者简介
通信作者:李江山,博士,研究员,从事污染场地工程修复和固体废弃物资源化研究,E-mail:jsli@whrsm.ac.cn。
