A kinetic model that describes the anaerobic cometabolism of 2,4-dinitrtoluene (DNT) with ethanol as the primary substrate has been developed based on experimental results. The kinetic parameters were estimated using the Levenberg-Marquardt algorithm. 2,4-DNT is anaerobically biotransformed to 2,4-diaminotoluene (DAT) via 4-amino-2-nitrotoluene (4-A-2-NT) and 2-amino-4-nitrotoluene (2-A-4-NT) by the bacteria whose growth is supported by utilizing ethanol. 2,4-DNT shows inhibition to its own biotransformation. It also exhibits a very strong competitive inhibition to further biotransformation of 4-A-2-NT and 2-A-4-NT. All the aromatics in the system, 2,4-DNT, 4-A-2-NT, 2-A-4-NT, and 2,4-DAT, inhibit the conversion of ethanol. Hydrogen produced from the acetogenesis of ethanol is utilized for the transformation of the nitroaromatics. The utilization of hydrogen and acetate by methanogenic bacteria is very strongly inhibited by the presence of the nitroaromatics. Acetate exhibits strong competitive inhibition to the biodegradation of propionate.