Enzymatic treatment of methyl orange dye in synthetic wastewater by plant-based peroxidase enzymes

• Published in: Journal of environmental chemical engineering 2016-06, Vol.4 (2), p.2500-2509
• Main Authors: Chiong, Tung, Lau, Sie Yon, Lek, Zhan Hong, Koh, Boon Yew, Danquah, Michael K.
• Format: Article
• Language: English
• Subjects: Enzyme bioremediation; Enzyme decolourisation; Enzyme treated wastewater; Organic dye effluents; Plant peroxidase
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2016.04.030

The search for effective and sustainable methods to degrade and remove recalcitrant dyes from textile effluents is a major research endeavor, owing to the escalating environmental and health concerns arising from the discharge of coloured effluents into water bodies. Plant-based peroxidases represent a reliable bio-resource for sustainable treatment of coloured effluents with the capacity to offer a continuous process for high throughput operation. The present study investigates the potential use of soybean peroxidase and Luffa acutangula (luffa) peroxidase, extracted from bio-wastes of soybean hulls and luffa skin peels respectively, for enzymatic degradation of azo dye methyl orange from liquid effluents. The enzymatic dye removal process was studied based on the consistent enzymatic activities of crude soybean peroxidase and luffa peroxidase extracts, which were 0.373UmL−1 and 0.355UmL−1 respectively. The effects of several process parameters including reaction time, pH, temperature, enzyme dosage, initial dye concentration and hydrogen peroxide concentration were investigated to optimise the performance of the enzymatic treatment process. Soybean peroxidase demonstrated a maximum dye decolourisation efficiency of 81.4% under the conditions of 1h incubation at 30°C using 2mM of hydrogen peroxide, 0.5mL crude soybean peroxidase and 30mgL−1 methyl orange at pH 5.0. Also, luffa peroxidase yielded a maximum decolourisation efficiency of 75.3% under the conditions of 40min at 40°C using 2mM hydrogen peroxide, 1.5mL crude luffa peroxidase and 10mgL−1 methyl orange at pH 3.0.