REACTOR DEVELOPMENT FOR PEROXIDASE-CATALYZED POLYMERIZATION AND PRECIPITATION OF PHENOLS FROM WASTE-WATER

Horseradish peroxidase enzyme catalyzes the oxidation of toxic aromati c compounds, especially phenols and aromatic amines, in the presence o f hydrogen peroxide. The reaction products polymerize to form high mol ecular weight materials which readily precipitate from solution; hence , providing a means for the treatment of wastewaters which contain aro matic compounds. The catalytic lifetime of horseradish peroxidase enzy me can be extended by optimizing treatment conditions such as pH and t emperature and by maintaining a low instantaneous enzyme concentration in the reaction mixture. The enzyme catalyzed polymerization process was implemented in a continuous stirred tank reactor (CSTR) configurat ion because reactant and enzyme concentrations are lowered immediately upon entering the reactor causing a reduction in inactivation of HRP through free radical bonding and compound III formation. Catalytic tur novers achieved in single and multiple CSTRs in series were significan tly higher than those observed in batch reactors when sufficient reten tion time was provided.