The 2D FUPG Finite Element Model of Contaminant Transportation in Soil Considering Nonlinear Sorption

The mathematical model of contaminant migration with the Langmuir isotherm equation to describe nonlinear equilibrium sorption in porous medium was developed in the present paper. The model was deduced based on the migration mechanism of pollutants in pore water of soil and the mass conservation. The two dimensional finite element models of the governing equations were discretized with the Full Upwind Petrov-Galerkin method (FUPG), and the nonlinear algebraic equations were received, and the program of the present finite element model was developed to solve the equations. Numerical simulations were carried out with the present model. The benchmark of 1D clay column was numerically analyzed, the influence of nonlinear equilibrium sorption on the transportation was studied. A two dimensional problem of the long term contamination transportation was analyzed. The numerical results show the stability of the current model and the ability of the program to analyze the contaminant transportation of nonlinear equilibrium sorption in clay, and the delay of absorption on the contamination transportation are exhibited.