| Trichloroethene (TCE) oxidation by methanotrophs is a cometabolic process constrained by competitive inhibition between TCE and methane. In this study, a mathematical model was developed for the degradation of TCE in a methanotrophic biofilm grown on a gas-permeable membrane with counter-current diffusion of methane and TCE into the biofilm. The model accounted for Monod kinetics, competitive inhibition, and decrease in active biomass concentration inside the biofilm with increasing distance from the membrane surface. An explicit finite differences method was used to solve the system of non-linear differential equations. The results from the counter-current model were compared with the results for a conventional co-current configuration. The TCE flux was predicted to be 2.9 x 10-5 mg/cm2-sec in the counter-current configuration, as compared to 4.9 x 10-5 mg/cm2-sec in the co-current configuration, a 70% increase. The model developed is general and can also be used for other chlorinated aliphatic hydrocarbons. |
