UV/H2O2 treatment of Rhodamine B in aqueous solution: Influence of operational parameters and kinetic modeling

The decolorization and degradation of Rhodamine B (RB) were investigated using UV radiation in the presence of H2O2 in a batch photoreactor at different light intensities. H2O2 and UV light have a negligible effect when they were used on their own. Removal efficiency of RB was sensitive to the operational parameters such as initial concentrations of H2O2 and RB, initial pH and light intensity. The results indicated that efficiency of process decreased with addition of inorganic ions and alcohols to the dye solution as hydroxyl radical scavengers. The semilogarithmic graphs of the concentrations of RB versus time were linear, suggesting pseudo-first order reaction for decolorization and degradation processes. A simple kinetic model is proposed which confirms pseudo-first-order reaction. The electrical energy per order (EE/O) values for decolorization and degradation of RB solution were calculated. Results shows that applying an optimum hydrogen peroxide concentration can reduce the EE/O.