Contaminant transport and biodegradation in saturated porous media: model development and simulation

A mathematical model is developed to describe the contaminant transport, sorption, and biodegradation in saturated porous media. In the model development, sorption was accounted for as a kinetic process for the contaminant transport. In addition, a double Monod function was incorporated into the model to describe the biodegradation of contaminants and utilization of oxygen. In the description of bacterial transport, reversible and irreversible depositions of bacteria were considered as kinetic processes in the model. The model equations were solved numerically with a fully implicit finite-difference method along with the Runge–Kutta method. The simulation showed that contaminant transport in porous media could be greatly affected by sorption and biodegradation processes. Sensitivity analysis demonstrated that the contaminant transport model was insensitive to the changes of desorption rate constant for contaminants kb, half-saturation constant for oxygen Ko, bacterial yield factor Y, and oxygen use coefficient F. However, the model was sensitive to the changes of adsorption rate constant for contaminants kf, maximum utilization rate of contaminants max, and half-saturation constant for contaminants Kc, and so their values should be selected carefully in the modelling process. Copyright  2005 John Wiley & Sons, Ltd.