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 using
peroxidases has been recognized as an environmentally friendly alternative
for phenol removal, but its broader application is limited by enzyme
instability and the inability to reuse free enzymes.
In this work, an innovative biocatalyst was developed by covalently
immobilizing horseradish peroxidase onto biomagnetite particles synthesized
in the presence of tangerine peel extract. The bioactive compounds
incorporated during synthesis enhanced particle stability and
functionalization, while glutaraldehyde served as a cross-linking agent for
enzyme attachment. The resulting biocatalyst exhibited high catalytic activity
(33.2 U/g at 30 °C, pH 6), retained over 60% activity across multiple reuse
cycles, and maintained stability during 30 days of storage. Batch experiments
using model phenol solutions (10 mg/L) demonstrated efficient removal,
achieving 93% degradation within 60 minutes in the presence of hydrogen
peroxide. Compared to the free enzyme, immobilized horseradish peroxidase
provided higher removal efficiency, improved reusability, and greater
operational stability. Due to its low-cost raw materials, simple preparation,
and strong catalytic performance, the developed biocatalyst offers a
promising solution for industrial wastewater treatment and regulation of
phenol concentration in aquatic systems.