IMMOBILIZED HORSERADISH PEROXIDASE ON BIOMAGNETITE PARTICLES FOR EFFICIENT REMOVAL OF PHENOL FROM WATER

Phenol is a highly toxic pollutant commonly found in industrial effluents,particularly from petrochemical, rubber, coal-processing, and dye industries,where its concentration can reach up to 185 mg/L. Enzymatic catalysis usingperoxidases has been recognized as an environmentally friendly alternativefor phenol removal, but its broader application is limited by enzymeinstability and the inability to reuse free enzymes.In this work, an innovative biocatalyst was developed by covalentlyimmobilizing horseradish peroxidase onto biomagnetite particles synthesizedin the presence of tangerine peel extract. The bioactive compoundsincorporated during synthesis enhanced particle stability andfunctionalization, while glutaraldehyde served as a cross-linking agent forenzyme attachment. The resulting biocatalyst exhibited high catalytic activity(33.2 U/g at 30 °C, pH 6), retained over 60% activity across multiple reusecycles, and maintained stability during 30 days of storage. Batch experimentsusing model phenol solutions (10 mg/L) demonstrated efficient removal,achieving 93% degradation within 60 minutes in the presence of hydrogenperoxide. Compared to the free enzyme, immobilized horseradish peroxidaseprovided higher removal efficiency, improved reusability, and greateroperational stability. Due to its low-cost raw materials, simple preparation,and strong catalytic performance, the developed biocatalyst offers apromising solution for industrial wastewater treatment and regulation ofphenol concentration in aquatic systems.