Single step peroxidase extraction and oxidation of highly concentrated ethanol and phenol aqueous solutions using supercritical carbon dioxide

Abstract

Extraction of peroxidase from raw vegetables using supercritical carbon dioxide (scCO2) and its simultaneous application for oxidation of organics in wastewater in the presence of hydrogen peroxide has been demonstrated. Ethanol and phenol were used as the model organic contaminants and potato and cabbage were employed as the sources of peroxidase. The extractions were carried out at 10MPa for 2h over a temperature range of 25°C to 60°C. Oxidation of ethanol increased by 330% when the treatment was carried out in the scCO2 medium compared to conventional aqueous medium when cabbage was employed, while use of potato as the enzyme source resulted in an increase of 85%. In the case of phenol, scCO2 exhibited a huge increase of 400% in presence of cabbage and 140% in presence of potato. Comparison of vegetable extracts with commercial horseradish peroxidase indicated the feasibility, importance and advantage of employing vegetables as a peroxidase source. This work presents the simultaneous extraction of enzymes and its application for oxidation of organics and opens up new opportunities for recovery of resources from unwanted/discarded plant materials and their use for environmental remediation in a single step.