Investigation the Zero-Valent Iron (ZVI) Performance in the Presence of UV light and Hydrogen Peroxide on Removal of Azo Dyes Acid Orange 7 and Reactive Black 5 from Aquatic Solutions

Colored wastewaters are known as one of the most important sources of environmental pollutants. Having toxic chemicals and aesthetic problems has made treatment of these wastewaters very crucial. So far a number of methods such as electrochemical treatment, coagulation and flocculation, and adsorption have been used for treatment of textile industries wastewater. Hence, the efficiency of zero-valent iron powder in the presence of UV light and hydrogen peroxide to remove Acid Orange 7 and Reactive Black 5 from the synthetic solutions was investigated. Conducting all experiments in a batch reactor, we examined different parameters including initial concentration of the color (25, 50, 75 mg/L), contact time (30, 60, 120 min), pH (3, 7, 11), the amount of iron powder (0.6, 1.3, 2 g/l), and hydrogen peroxide concentration (10, 15, 20 ml/l). The results showed that dye removal efficiency was increased by increasing contact time, the amount of iron powder and hydrogen peroxide concentration. On the other hand, with the increasing pH and initial concentration of dye, removal efficiency decreased in both AO7and RB5 dyes. We found that the integrated ZVI/UV/H2O2 method has high efficiency in removing azo dyes Acid Orange 7 and Reactive Black 5.