Date of Award


Publication Type

Master Thesis

Degree Name



Civil and Environmental Engineering


Engineering, Civil.


Bewtra, J. K.,




Laccase, as a developmental preparation from an industrial enzyme producer, catalyzes the oxidation of selected aromatic compounds. The polymers formed from the reaction are insoluble and are readily removed from solution. Experiments were conducted to evaluate the potential use of laccase in an alternative enzyme-based technology to remove cresols from synthetic wastewater. Reaction parameters were optimized in unbuffered tap water for the removal of o-, m-, and p-cresols. The effects of pH, enzyme dose, PEG addition, dissolved oxygen availability, and hydrogen peroxide addition were investigated. All tests were conducted in continuously stirred batch reactors. Nearly 90% of o-cresol was removed at optimum conditions of pH and enzyme dose, while p- and m-cresols' removals were 80% and 70%, respectively. The optimum pH for the cresols ranged from 5.6 to 7.0. For each substrate, the optimum enzyme dose varied from 0.3 standardized units of catalytic activity for p-cresol to 0.6 standardized units of catalytic activity for m-cresol. Aeration, at higher concentrations of substrate, increased the initial rate of reaction for substrate removal and improved the efficiency of the reaction. The addition of PEG or hydrogen peroxide did not have significant effects on substrate removal. The results from this study have demonstrated the applicability of laccase for the reduction of cresols from wastewater. This study provides a basis for further investigation's into similar enzymatic treatment.Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2000 .V37. Source: Masters Abstracts International, Volume: 39-02, page: 0556. Advisers: J. K. Bewtra; K. E. Taylor. Thesis (M.A.Sc.)--University of Windsor (Canada), 2000.