Enhanced sequestration of commercial Auramine O dye in a Fenton oxidative decolourization process

Abstract

The present work investigates the Fenton degradation of commercial Auramine O dye from a model solution through advanced oxidation process (AOP). The effects of initial pH, ferrous ion and H2O2 concentration have been evaluated with respect to the extent of decolourization of the feed solution. A maximum decolourization to the tune of 91.8% is accomplished at a pH of 3.0. The effect of various doses of Fe2+ and H2O2 on the percentage reduction in chemical oxygen demand (COD) is investigated at a constant pH. 84.9% reduction of COD is obtained using a combination of 48 mL/L H2O2 and 6 g/L Fe2+. The gas chromatography-mass spectrometry analysis reveals the presence of toxic non-biodegradable Auramine O dye in the model solution before the Fenton AOP, which is degraded into several compounds including CO2 after 30 min of Fenton AOP. The spectral output from FTIR analysis corroborates the molecular rearrangement during Fenton process with consequent degradation.