Degradation of azo dye with horse radish peroxidase (HRP)

Abstract

Azo dyes are recalcitrant carcinogenic compounds and have dermal and immunological effect on human beings. Conventional methods are not effective in the treatment of azo dyes. The oxidation capability of horse radish peroxidase (HRP) and hydrogen peroxide (H2O2) on direct yellow 12 dye was investigated and was found to be very effective treatment methodology. HRP was extracted from horse radish roots, and its performance was evaluated in soluble and immobilized form by conducting batch experiments in the presence of H2O2. The oxidation of direct yellow-12 dye was tested as a function of HRP at fixed concentration of H2O2, and at constant HRP activity (1.8 units/ml). Parameters such as aqueous-phase pH, H2O2 concentration, dye and enzyme concentrations were studied.