COMPARATIVE ANALYSIS MgO AND TiO2 NANOCATALYST IN DEGRADATION OF REACTIVE BLUE 13 DYE

Abstract

Background: Synthetic dyes, especially azo-based compounds like Reactive Blue 13, are widely used in the textile industry and pose significant environmental hazards due to their stability and resistance to biodegradation. Photocatalysis using metal oxide nanoparticles offers a sustainable approach for degrading such dyes in wastewater. Titanium dioxide (TiO₂) and magnesium oxide (MgO) nanoparticles have demonstrated high catalytic activity under UV irradiation, yet their comparative efficiency under varying operational parameters remains underexplored.

Objective: To evaluate and compare the photocatalytic degradation efficiency of Reactive Blue 13 dye using TiO₂ (anatase) and MgO nanoparticles under UV light by optimizing pH, catalyst dosage, and dye concentration.

Methods: Reactive Blue 13 stock solutions (1000 ppm) were prepared and diluted for experimental use. Photocatalytic degradation was carried out in a controlled photoreactor under UV light, with pH adjusted using 0.1 M HCl and NaOH. Catalyst dosages ranged from 0.01 g to 0.15 g, and dye concentrations varied from 10 ppm to 40 ppm. UV-Vis spectrophotometry was employed to monitor absorbance at λmax = 574 nm. Degradation efficiency was calculated as a percentage reduction in dye concentration over time.

Results: TiO₂ showed maximum degradation efficiency (98%) at 10 ppm dye concentration, pH 10, and 0.1 g catalyst dose. MgO achieved 97% efficiency at the same dye concentration with a pH of 11 and 0.05 g catalyst dose. Efficiency declined at higher dye concentrations due to light penetration limits and active site saturation.

Conclusion: Both TiO₂ and MgO are effective photocatalysts for degrading Reactive Blue 13 dye, with MgO demonstrating broader pH tolerance and TiO₂ showing peak efficiency under alkaline conditions. These findings underscore the importance of parameter optimization for real-world wastewater remediation applications.