Degradation of rhodamine B in water by ultrasound-assisted TiO2 photocatalysis

Abstract Rhodamine B is widely used in the dyeing of paints, acrylic and other fabrics as well as biological products. It is highly toxic to organisms when directly discharged into water. To this end, in this paper, degradation of Rhodamine B in water by ultrasound-assisted TiO2 photocatalysis was investigated. The effects of various factors, such as the amount of catalyst, the speed of mechanical stirring, the frequency of ultrasonic vibration, the ultrasonic output power, the initial pH value of the reaction solution, the initial concentration of Rhodamine B, the introduced air, and physical adsorption, etc., on the degradation of Rhodamine B in wastewater were studied, and the optimal degradation conditions were obtained: rotational speed, pH value, initial rhodamine B concentration, ultrasonic vibration frequency, output power and TiO2 nanoparticles dosage were 500 r/min, 7, 20 mg/L, 40 kHz, 300 W and 500 mg/L respectively. Finally, degradation mechanism was discussed. The results indicate that ultrasound-assisted TiO2 photocatalysis method is of great potential application value in removal of organic pollution and environmental purification.