Degradation of Methyl Red using Fenton's reagent and the effect of various salts

Waste effluents from textile industries are a major source of water pollution. These waste streams contain numerous toxic dyes, which are resistant to natural breakdown and degradation. Therefore, there is a need to find economical and bio-friendly methods to degrade textile dyes. In this study, degradation of Methyl Red, an azo dye, was studied using the ferrous-hydrogen peroxide system. The oxidation and subsequent degradation of the dye was found to be dependent on both the amount of Fe²⁺ ions as well as hydrogen peroxide. In order to study the effect of other salts that are normally present in textile waste streams, a systematic study was carried out using 10 different salt solutions. Some of the ions tested enhanced the rate and extent of degradation of the dye, whereas some had an inhibitory effect. The rates of degradation were found to fit to first-order kinetics.