Effects of catalyst preparation method and reaction parameters on the ultrasound assisted Photocatalytic oxidation of reactive yellow 84 dye.

In this study, the Heterogeneous Sono-photocatalytic Process was used to degrade Reactive Yellow 84 (RY 84) dye dissolved in water over iron containing TiO2 and TiO2-Ce catalysts. The catalysts were prepared by sol-gel and incipient wetness impregnation methods and characterized using XRD, SEM, Nitrogen adsorption, UV-Vis DRS and ICP-AES measurements. The TiO2 catalyst containing 1% (in weight) iron, prepared by incipient wetness impregnation technique and calcined at 300 °C (1%Fe/TiO2-300 °C (IW)) was found to be the most effective catalyst. Parametric study was carried out over this catalyst and COD removal of 55% and TOC removal of 38% were achieved while the decolorization efficiency reached 100% after 45 min of reaction at the optimum conditions of, (25 mg/L of RY 84 solution, 0.5 g/L of catalyst, 5 mM of H2O2, a temperature of 25 °C, pH = 6 and US at a power of 40 W). Decolorization of RY 84 obeyed the first order kinetics with an activation energy of 20.7 kJ/mol. Sonication increased the decolorization efficiency of the heterogeneous Fenton process (UV + Catalyst+H2O2) from 92.7% to 97.5% after 30 min of reaction, with the COD and TOC reductions increasing from 87% to 90% and 48% to 57% after 120 min of reaction, respectively. US also decreased the toxicity of the RY 84 dye. The results obtained from this study show that, iron containing TiO2 and TiO2-Ce catalysts could be efficiently used in the hybrid process of ultrasound assisted heterogeneous photocatalytic oxidation in a wide range of experimental conditions. © Springer Nature Switzerland AG 2020.