Enzymatic treatment of synthetic wastewater containing 2,4-dimethylphenol (2,4-DMP) was investigated in the presence and absence of polyethylene glycol (PEG) by the enzyme soybean peroxidase. The optimum pH both in the absence and in presence of PEG was 8.0. The optimum [hydrogen peroxide]/[2,4-DMP] was between 0.9-1.2. A linear relationship existed in presence of PEG between the minimum SBP concentration and initial 2,4-DMP concentrations. In the absence of PEG, a linear relationship did exist at lower substrate concentrations up to 2.0 mM, beyond which the minimum enzyme concentration remained constant and independent of the initial substrate concentration. At lower 2,4-DMP concentrations, there was PEG effect which decreased to almost nil with increase in substrate concentrations. Minimum PEG concentration for 1 mM of 2,4-DMP was found to be 45-50 mg/L. Preliminary kinetic study of the enzyme-catalyzed reaction yielded the values of Michaelis-Menten constants for 2,4-dimethylphenol, in the presence and absence of PEG
