Decolorization of Rhodamine B by a Photo-Fenton Process: Effect of System Parameters and Kinetic Study

A low-energy photo-Fenton process is carried out in this study to investigate the effect of pH, temperature, Fe2+ and H2O2 dosages on the decolorization of Rhodamine B dyeing wastewater. Experimental results indicate that the decolorization efficiency of Rhodamine B by UV light illumination only and UV/H2O2 (H2O2 of 30 to 90 mg/L) are insufficient. Decolorization efficiency is remarkably enhanced to more than 83% by the photo-Fenton process at pH 5.5 and the pseudo first-order kinetic rate constants are in the range of 13.6-14.7×10-3 min-1. The optimal reaction condition is found at pH 3, H2O2 30 mg/L; Fe2+ 8 mg/L and 30oC followed by 98.3% decolorized efficiency of Rhodamine B. In conclusion, the photo-Fenton process can effectively decolorize the Rhodamine B in short reaction time under proper condition. Additional H2O2 and Fe 2+ dosages and the reaction temperature up to 30 o C