Degradation of Acid Scarlet 3R dye using oxidation strategies involving photocatalysis based on Fe doped TiO2 photocatalyst, ultrasound and hydrogen peroxide

The presence of contaminants like dyes in the wastewater which is discharged into the environment causes serious effects on human health and living organisms. The current work deals with the degradation of Acid Scarlet 3R dye based on photocatalysis and photocatalysis combined with ultrasound and hydrogen peroxide to find the best treatment strategy. Fe doped TiO2 with 0.4 mol% of Fe doping, which is synthesized employing ultrasound-assisted co-precipitation method is used as the photocatalyst for the study. The work targets on understanding the effect of the operating conditions to establish the best conditions for treatment as pH of 3, ultrasonic power as 60 W, pulse cycle as 70%, catalyst dosage as 0.2 g/L and power of UV as 16 W. Under the optimized conditions, combination of photocatalysis with H2O2 at best loading of 50 ppm was demonstrated to yield maximum decolorization as 91.15% and COD reduction as 75.4%, which was also higher as compared to the combination of photocatalysis with ultrasound. It was also noticed that the degradation rate could be explained with pseudo-first-order kinetics. It was clearly demonstrated that the approach of combined photocatalysis with H2O2 was the best treatment strategy giving maximum dye degradation.