Application of Immobilized Tyrosinase for Phenol Degradation in Batch and Continuous Operation Modes

Abstract

Conventional technologies for degradation of phenolic compounds encounter several challenges such as large energy consumption and sludge production. Enzymes, natural catalysts displaying a superb selectivity, can be used for phenol removal. In the present work, tyrosinase immobilized on cellulosic support was used for degradation of phenol in batch and continuous operation modes in different conditions. In this regard, the effect of concentration, flow rate and pH on degradation yield were investigated. The results proved that higher oxidation rates were clearly achieved in continuous operation compared with batch experiments. The pH of 6 and 7 were suitable for phenol removal. In continuous mode, the complete phenol degradation was observed where the initial phenol concentration of 25 ppm was applied at residence times between 3.1 and 6.4 min. However, the greatest overall degradation yield of 71% was obtained with the initial concentration of 25 ppm by utilizing the flow rate of 18 ml/h. The degradation yield of 54% was found in recycling modes at initial phenol concentration of 25 ppm and a flow rate of 30 ml/h. Based on the results, degradation of phenol using tyrosinase can be considered as a valuable and green method.

Keywords

• tyrosinase
• bioreactor
• biocatalyst
• phenol degradation
• continuous process