Degradation of Rhodamine dye using a fluctuating flow type photocatalytic reactor byexternal oxidants

Abstract A fluctuating flow type photocatalytic reactor was used to investigate the degradation of Rhodamine B on a large scale. The effect of initial dye concentration and operating solution pH on the degree of Rhodamine B degradation has been studied. The Rh B dye degradation is larger at a lower solution pH (pH 2) than at a higher pH and at a lower initial (20 ppm) dye concentration. The degradation of rhodamine B in the presence of process-intensifying additives like hydrogen peroxide and Fenton reagent was found to be greater than that reported in the presence of photocatalysts TiO2, ZnO, and CaO. The amount of degradation was reported to be 83.3% at optimum loading of TiO2 (1 g/L), while it was 76.2% at 1.5 g/L ZnO and 65.9% at 1.5 g/L CaO. Titanium dioxide is the most effective photocatalyst among all of the photocatalysts used in this investigation. Among all processes investigated in this study, the combined UV/Fenton process had the highest degradation of 94.8% and the highest COD removal of 68.4%. TiO2 (58.3%) eliminated the most COD during the fluctuating photocatalytic reactor flow, followed by ZnO and CaO. Overall, combined UV/Fenton operation demonstrated the maximum efficacy when utilizing a zig zag flow photocatalytic reactor.