Abstract
Phenols are very dangerous contaminants found in wastewater. Discharge of these compounds without treatment is highly serious risks to living organisms. The present study offers new effective immobilized peroxidase for phenol removal from wastewater. Nano peroxidase particles were prepared through immobilization of peroxidase enzyme extracted from onion dry scales (one of the wastes in food industry) on Silica nano particles prepared from rice straw (one of the most spread agriculture wastes). Immobilization improved the physiochemical properties of the enzyme which allowed the immobilized enzyme to be more resistant and stable under various hard conditions such as high temperature, pH changes or presence of metal ions. The nano peroxidase retained about 77.8 % of its activity after incubation at 80 °C. The affinity between the nano peroxidase and its substrate increased about 2.3 fold more than that of the free one. Peroxidase nanoparticle retained 90 % of residual activity till 50th reuse cycle. Thus, the method applied in this study increased stability and reusability of peroxidase, and therefore, it can be used for efficient phenol removal from wastewater.