Enhanced Sonochemical Degradation of Rhodamine B in Aqueous Solutions: The Role of Additives

Abstract

In the last few years, the control of water pollution due to hazardous dyes has become increasingly important. Sonochemical degradation has recently been reported as an appropriate and attractive process for the treatment of toxic dyestuffs. This study investigates the breakdown of dye molecules in aquatic media using ultrasonic irradiation to clarify the degradation mechanism. Experiments were conducted in a 50–60 Hz ultrasonic reactor with 100 mL dye solutions at the concentration of 25 mg/L. The effects of various additives, including inorganic salts (FeSO4, NaCl, Na2SO4, NaNO3), hydrogen peroxide, carbon tetrachloride, Glucose, and Sucrose, the sonochemical degradation of Rhodamine B (RhB) was investigated. Results showed that degradation was highly influenced by the initial concentration of the substrate and pH. Addition of FeSO4 enhanced RhB degradation, while increased CCl4 concentrations accelerated removal through oxidant chlorine species. Presence of H2O2 and Na2SO4 also improved the degradation efficiency. NaCl and NaNO3 also enhanced the degradation. However, higher glucose and sucrose concentrations marginally decreased the breakdown efficiency, indicating that radiation from ultrasonic waves remains an encouraging approach for the removal of RhB, even in complex aqueous systems.