Effect of Some Metal Ions on the Photocatalytic Oxidation of Remazol Black B in Aqueous Solution under UV Irradiation

This study investigates the advance oxidation process of common azo dye, Remazol Black B (RBB). Photocatalytic degradation of RBB was carried out using metal ion (Fe3+, Cu2+, Sn2+, Hg2+, and Co2+) as photocatalyst. Fe3+, Cu2+, and Sn2+ were used in varying all the necessary parameters in the photodegradation experiment while all five metal ions were used for the comparison of photodegradation efficiency of different metal ions in the optimal conditions that were obtained for the treatment of RBB using first three metal ions. Fe3+ ion was widely used to demonstrate the photodegradation pattern. The degradation efficiency was observed above 90% after 90 minutes irradiation of UV light (intensity=12.83 Wm(-2)). Different kinetic models have been used to interpret the results and found that the kinetics of the degradation follow pseudo first-order model. Photodegradadation was carried out by varying the concentration of metal ion, initial concentration of RBB, the pH of the medium and light sources using each of the three metal ions (Fe3+, Cu2+, and Sn2+). A tentative mechanism has been proposed to demonstrate this photocatalytic activity. More efficient degradation for all metal ions was observed at pH=1.0. Treatment performance of the investigated advanced oxidation systems was comparatively assessed in terms of bleaching and evaluated by spectrophotometric measurements.