On the ultrasonic degradation of Rhodamine B in water: kinetics and operational conditions effect.

The aim of this present study was to investigate the degradation of Rhodamine B (RhB) in aqueous solution under the influence of ultrasound irradiation. An ultrasonic reactor was used to investigate the effect of different operational parameters such as dye initial concentration, ultrasound power, pH and electrical conductivity. The results showed an increase in decolourization rate with decreasing pH, but colour removal efficiency decreased with increasing initial dye concentration. It was found that an optimum electrical conductivity of the solution exists on enhancing the degree of RhB degradation. Sonolytic degradation data from the present and other works in the literature were analysed by Langmuir-type kinetics. The apparent reaction rate constant was strongly influenced by both irradiation power density and frequency, and based on the experimental data a mathematical correlation between them was obtained.