Kinetics of simultaneous degradation of 4-bromophenol and 4-chlorophenol by Arthrobacter chlorophenolicusA6

Biodegradation of p-bromophenol (4-BP) along with p-chlorophenol (4-CP) was investigated in batch shake flasks using a actinomycetes strain of Arthrobacterchlorophenolicus A6. A Two level full factorial design at two different levels (low and high) was applied to perform the biodegradation of 4-CP and 4-BP in the mixed substrate system. Result reveals that the presence of 4-CP in low concentration range in the mixture (20–60 mgl-1) did not inhibit 4-BP biodegradation by the actinomycetes. However, at high concentration range of 4-CP (100-200 mgl-1), the 4-BP biodegradation was inhibited. Further, 4-BP degradation was faster than 4-CP. In order to study variation in the specific degradation rate of these pollutants and their interaction effect exist between them, the experimental data were fitted to a sum kinetics model. The experimental data have been fitted with the model with a high correlation coefficient value (R2> 0.94). The model fitted data reveals a strong negative interaction effect of 4-CP on biodegradation of 4-BP by the A. chlorophenolicusA6.