Degradation of rhodamine dye using a modified flow photocatalytic reactor in the presence of external oxidants

Abstract

The current work addresses the challenge of effectively degrading Rhodamine B dye, a common environmental pollutant using a modified zig‐zag flow type photocatalytic reactor with the main objective of process intensification. A detailed study into the effect of initial dye concentration and operating solution pH on the degradation of Rhodamine B elucidated that the Rh B dye degradation was higher at a lower solution pH (pH 2) and at an optimum initial (20 ppm) dye concentration. Among different photocatalysts studied including TiO2, ZnO, and CaO, maximum degradation was seen for the TiO2 with 83.3% at optimum loading of TiO2 (1 g/L). Lower degradations of 76.2% at 1.5 g/L of ZnO and 65.9% at 1.5 g/L of CaO were seen for other photocatalysts. Additionally, the introduction of oxidants such as hydrogen peroxide and Fenton reagent further intensified dye degradation, with the combined UV/Fenton process achieving maximum degradation of 94.8% and the highest COD removal of 68.4%. Overall, it is recommended to utilize zig‐zag flow design photocatalytic reactor with combined Fenton's reagent for optimal dye degradation.