A mathematical model was developed to describe the sequential dechlorination of 2,4,6-trichlorophenol to 2,il-dichlorophenol, 4-chlorophenol and phenol. Each compound was assumed to be degraded according a Michaelis-Menten expression. Experimental data were used to obtain the model kinetic constants and to test its validity. Good agreement between the model predictions and the experimental data was obtained.