Oxidation of Electron-rich Pollutants Using Peroxidase from Fenugreek Waste

Aims: To assess the capacity of peroxidase from non-edible fenugreek waste for removal of phenol, a model electron-rich pollutant, from synthetic wastewater.

Study Design: This study involved one-factor-at-a-time analysis. Reaction parameters such as pH of reaction mixture and concentrations of phenol and hydrogen peroxide were optimized one at a time.

Place and Duration of Study: Plant Biotechnology Research Laboratory, Ramniranjan Jhunjhunwala College, Mumbai between 2014 and 2015.

Methodology: The oxidative removal of the model pollutant, phenol, was assessed at ambient temperatures. The pH as well as concentrations of phenol and hydrogen peroxide were varied to optimize each reaction parameter. Each parameter was optimized singly while maintaining the other parameters constant.

Results: The maximum activity (in guaiacol units) of peroxidase was observed at pH 6.0 in the presence of 6 mmol L−1 hydrogen peroxide. The removal of phenol achieved was maximum, 64.29% in 24 h, when the initial phenol concentration was 2 mmol L−1. Phenol removal proceeded through oxidative polymerization and settling of flocs.

Conclusion: The non-edible waste from fenugreek is a rich source of crude peroxidase from which the enzyme can be easily extracted. The use of vegetable waste as a source of a bioremediative enzyme is the primary focus of this work. This crude enzyme has potential for use in wastewater treatment by the oxidative degradation of electron-rich pollutants, such as phenols, amines, and azo dyes.