Biotransformation of phenol in synthetic wastewater using the functionalized magnetic nano-biocatalyst particles carrying tyrosinase.

Low conversion efficiency and long-processing time are some of the major problems associated with the use of biocatalysts in industrial processes. In this study, modified magnetic iron oxide nanoparticles bearing tyrosinase (tyrosinase-MNPs) were employed as a magnetic nano-biocatalyst to treat phenol-containing wastewater. Different factors affecting the phenol removal efficiency of the fabricated nano-biocatalyst such as catalyst dosage, pH, temperature, initial phenol concentration, and reusability were investigated. The results proved that the precise dosage of nano-biocatalyst was able to degrade phenol at the wide range of pHs and temperatures. The immobilized tyrosinase showed proper phenol degradation more than 70%, where the substrate with a high concentration of 2500 mg/L was subjected to phenol removal. The nano-biocatalyst was highly efficient and reusable, since it displayed phenol degradation yields of 100% after the third reuse cycle and about 58% after the seventh cycle. Moreover, the immobilized tyrosinase was able to degrade phenol dissolved in real water samples up to 78% after incubation for 60 min. It was also reusable at least seven cycles in the real water sample. The results proved the effectiveness and applicability of the fabricated nano-biocatalyst to treat phenol-containing wastewaters in a shorter time and higher efficiency even at high phenol concentration. The developed nano-biocatalyst can be promising for the micropollutants removal and an alternative for the catalysts used in traditional treatment processes.