Kinetic study on the removal of toxic phenol and chlorophenol from waste water by horseradish peroxidase

Abstract

The removal of phenol and chlorophenol from waste water catalyzed by horseradish peroxidase was studied in this paper to understand the kinetic features of this reaction. The effects of pH, H 2O 2 concentration and substrate type on the removal of pollutants were discussed in detail. The results showed that the optimum pH for the removal efficiency of phenol and chlorophenol was 9. 0 in the test pH range of 5. 0 to 9. 0. The results also indicated that there was an optimum H 2O 2 concentration for pollutants removal catalyzed by horseradish peroxidase and H 2O 2 at concentrations higher than the optimum value had inhibition effect on pollutant removal. But the inhibition effect of higher H 2O 2 concentrations was very small and had little influence on the reaction. Several substrates were compared on their affinity with horseradish peroxidase according to the kinetics parameters of reactions. The results showed that phenol and 4-chlorophenol were more easy to be removed than 3-chlorophenol. It was also concluded in this paper that oxidation reaction catalyzed by horseradish peroxidase had the characteristic of Ping-Pang reaction.