SOLUTE TRANSPORT MODELLING IN LOW-PERMEABILITY HOMOGENEOUS AND SATURATED SOIL MEDIA

Rudarsko-geološko-naftni Zbornik

Hadayat Ullah¹  Fawaz Manzoor²  Saad Ahmed Mashwani²  Ehsan ul Haq²  Syed Husnain Ali Shah²  Muhammad Zaheer² 

[1] School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China;Department of Geology, Hazara University Mansehra 21300, Khyber Pakhtunkhwa, Pakistan;

关键词: low permeability;    relative concentration;    non-fickian;    continuous-time random walk;   

DOI  :  10.17794/rgn.2021.2.3

来源: DOAJ

【 摘 要 】

Fickian and non-Fickian behaviors were often detected for contaminant transport activity owed to the preferential flow and heterogeneity of soil media. Therefore, using diverse methods to measure such composite solute transport in soil media has become an important research topic for solute transport modeling in soil media. In this article, the continuous-time random walk (CTRW) model was applied to illustrate the relative concentration of transport in low-permeability homogeneous and saturated soil media. The solute transport development was also demonstrated with the convection-dispersion equation (CDE) and Two Region Model (TRM) for comparison. CXTFIT 2.1 software was used for CDE and TRM, and CTRW Matlab Toolbox v.3.1 for the CTRW simulation of the breakthrough curve. It was found that higher values of determination coefficient (R2) and lower values of root mean square error (RMSE) concerning the best fits of CDE, TRM, and CTRW. It was found that in the comparison of CDE, TRM, and CTRW, we tend to use CTRW to describe the transport behavior well because there are prevailing Fickian and non-Fickian transport. The CTRW gives better fitting results to the breakthrough curves (BTCs) when β has an increasing pattern towards 2.00. In this study, the variation of parameters in three methods was investigated and results showed that the CTRW modeling approach is more effective to determine non-reactive contaminants concentration in low-permeability soil media at small depths.

【 授权许可】

Unknown