On the simultaneous determination of dispersion and nonlinear adsorption parameters from displacement tests by using numerical models and optimization tehcniques

The simultaneous determination of the dispersion and nonlinear adsorption (Freundlich or Langmuir) parameters is obtained automatically by matching results of numerical models with the breakthrough curve measured during a laboratory displacement test. This matching is performed by applying multivariate optimization techniques to minimize the differences between numerical and experimental results. Numerical solutions are obtained by solving the convection-dispersion-nonlinear adsorption equation by finite differences using the Crank-Nicolson method with iterations to account for nonlinearities.