Impact of Toxic Organic Chemicals on the Kinetics of Acetoclastic Methanogenesis

摘要

A knowledge of the effect of toxic organic chemicals on the biotransformation characteristics of organic co-substrates is essential for predicting the impact of these chemicals in anaerobic processes. Bench-scale tests were conducted to assess the impact of toxic organic chemicals on the kinetics of acetoclastic methanogenesis and to determine the relationship between kinetic parameters obtained under non-toxic and toxic conditions. A computer model based on a finite difference non-linear least squares algorithm was used to calculate the kinetic parameters by obtaining a best-fit of the experimental data to the Michaelis-Menten substrate utilization model. Resulting kinetic coefficients revealed significant changes in both the maximum rate of acetate conversion, and the half-velocity coefficient, when using both chlorophenols and chloroanilines. Therefore, mixed inhibition was occurring. However, non-competitive mechanisms predominated with chemicals containing the 2-chloro functional group while competitive mechanisms seemed to predominate with the 3- and 4-chloro functional groups.