A simple and efficient method for removal of phenolic contaminants in wastewater using polyacrylamide entrapped mushroom tyrosinase

ABSTRACT

Phenolic compounds are priority pollutants with high toxicity even at low concentrations. Ever-increasingburden of pollutants in major rivers and other water bodies along with stringent environmental legislationand focus on adaptation to eco-friendly treatment approaches have necessitated the need for the removal ofthese phenolics before being discharged to rivers and other freshwater bodies. Compared to physicochemicaltreatment, enzymatic treatment has proven to be the best way to treat various phenolic compounds undermild conditions with different enzymes such as peroxidases, laccases, and tyrosinases. In this study, we havedesigned a simple and efficient method for removal of phenols from effluent wastewater using an immobilizedpreparation of mushroom tyrosinase. The enzyme was isolated from Agaricus bisporus (button mushroom)and partially purified, and subsequently, various immobilization matrices were evaluated for their efficiencyof immobilization, reproducibility, rate of degradation of phenolics, stability, and reusability. Experimentsshowed that the in situ polymerization of acrylamide monomer along with the enzyme gave the most effectiveentrapment with high reproducibility among the tested methods. Immobilized tyrosinase was much more stablethan the free tyrosinase in storage and that the immobilized tyrosinase could even retain about most of itsoriginal activity after repeated use of 10 times in a batch system. This method could provide and an economicaland stabilized immobilized-enzyme method for the removal of phenol in wastewater.