Probing horseradish peroxidase catalyzed degradation of azo dye from tannery wastewater

Abstract

Biocatalysis based effluent treatment has outclassed the presently favored physico-chemical treatments due to nil sludge production and monetary savings. Azo dyes are commonly employed in the leather industry and pose a great threat to the environment. Here, we show the degradation of C. I. Acid blue 113 using horseradish peroxidase (HRP) assisted with H2O2 as a co-substrate. It was observed that 0.08 U HRP can degrade 3 mL of 30 mg/L dye up to 80% within 45 min with the assistance of 14 μL of H2O2 at pH 6.6 and 30°C. The feasibility of using the immobilized HRP for dye degradation was also examined and the results show up to 76% dye degradation under similar conditions to that of free HRP with the exception of longer contact time of 240 min. Recycling studies reveal that the immobilized HRP can be recycled up to 3 times for dye degradation. Kinetics drawn for the free HRP catalyzed reaction marked a lower Km and higher Vmax values, which denotes a proper and faster affinity of the enzyme towards the dye, when compared to the immobilized HRP. The applicability of HRP for treating the actual tannery dye-house wastewater was also demonstrated.Electronic supplementary materialThe online version of this article (doi:10.1186/2193-1801-2-341) contains supplementary material, which is available to authorized users.

Characterization of Plant Peroxidases and Their Potential for Degradation of Dyes: a Review

“…Acid Blue 113 dye mediated by horseradish peroxidase is higher at low concentration of dye from 20 to 30 mg/l. Beyond which, the degradation of dye is decreasing abruptly as the concentration of dye increases [92]. Terres et al [90] reported that a dye concentration of 2.5×10 −5 mol/l of Indigo Carmine dye was decolorized by 2 mg of horseradish peroxidase.…”

“…Gholami-Borujeni et al [91] evaluated that decolorization of acid blue-25 (AB-25) dye with horseradish peroxidase was maximum at pH 7 and 0.8. Preethi et al [92] explored that the horseradish peroxidase exhibited higher percentage of color removal of C.I. Acid Blue 113 dye at various pH values such as 4, 6.6, and 9.…”

“…The incubation time of 160 min were required for decolorization of 60 ppm of Drimarene orange KGL by 33 U/ml of orange peroxidase [79]. Preethi et al [92] mentioned that 30 mg/l of C.I. Acid Blue 113 dye was maximally degraded with 0.08 U of horseradish peroxidase in 45 min of contact time.…”

“…The horseradish peroxidase concentrations of 0.08 U can degrade 30 mg/l of C.I. Acid Blue 113 dye up to 80 % [92]. A dye concentration of 2.5×10 −5 mol/l of Indigo Carmine dye was decolorized by 2 mg of horseradish peroxidase [90].…”

“…Maximum color removal of C.I. Acid Blue 113 dye with horseradish peroxidase was achieved at 20°C [92]. The maximum decolorization of Drimarene orange KGL by orange peroxidase was obtained at 60°C [79].…”