Abstract: The Langmuir’s isothermal equation is employed to consider the nonlinear sorption characteristics. The improved mixing cell method is applied in the numerical analysis of contaminant transport in saturated porous medium. The combined effects of both nonlinear and nonequilibrium sorption on contaminant migration are examined. The computed results show that while the nonequilibrium and nonlinear sorption is considered, the breakthrough curve generally exhibits sharp fronts with a forward-shifted peak and shorten tailing. Both the parameter B in Langmuir isotherm equation and hydraulic conductivity of compacted clay liners as well as seepage velocity of groundwater play significant roles in governing contaminant transport through porous media.

Key words: nonequilibrium sorption process, non-linear sorption behaviour, contaminant transport, break through curve, peak concentration of contaminant