Evaluation of CDE and MIM models to transfer Trichloroethylene (TCE) in a carbonate porous media using inverse solution method

this research, an inverse solution has been employed to simulate the movement of TCE. To evaluate inverse solution, HYDRUS-1D (asa numerical solution) and STANMOD (as an analytical solution) software were used with two transport models including: convection-dispersion equation (CDE) and Mobile-Immobile model (MIM)). In this study, a set of data from Yolcubal and Akyol (2001) were used at three TCE concentrations of 110, 113 and 1300 mg/L. The research was conducted on the loamy-sand and carbonate soil with a mean bulk density of 1.2 g/cm3. Experiments were carried out in columns with a length of 15 cm in stainless steel in saturated conditions. TCE injection continued until the effluent concentration was equal to the injection concentration (C/C0=1). At different time step, the water samples of the column output were taken to determine the TCE concentration and the breakthrough curves (BTC). The results of HYDRUS-1d and STANMOD software showed that the MIM model had a higher correlation coefficient than the CDE model with respect to the match BTC. The highest correlation coefficient was 0.97 at the concentration of 1300 mg/L with inverse-analytical solution and MIM model. The minimum error was zero for estimation of the dispersion coefficient (D) at CDE where it is 3.5% at MIM. The error rate was minimum at the concentration 113 mg/L for adsorption isotherm (Kd) coefficients in the inverse numerical solution and the same result for retardation factor (R) in an inverse-analytical solution. It means that the rate was higher at the other two TCE concentrations.