Performance of the photo-Fenton process in the degradation of a model azo dye mixture

Abstract

The degradation of a model mixture composed of Acid Yellow 36 (AY36) and Methyl Orange (MO) azo dyes was performed using the photo-Fenton process (PFP). The performance of this process conducted under artificial UV light (365 nm) was compared with the Fenton reaction. Some important operating parameters that affect the degradation of azo dyes, such as initial Fe²⁺ and H₂O₂ concentrations and the presence or absence of chloride ions, were investigated. Decolorisation of the dye mixture sample was achieved in 70 min with the photo-Fenton reaction, while the complete mineralization evaluated by TOC abatement was completed in 180 min. These results provide important knowledge for the treatment of wastewater containing azo dye mixtures by Fenton and photo-Fenton oxidation processes.