The Use of Sonochemical Technology for Cyanide Removal from Aqueous Solutions in the Presence of Hydrogen Peroxide

Cyanide is a highly toxic species that found mostly in industrial effluents such as electroplating, metal mining, metallurgy and metal cleaning processes. Discharge of it into the enviroment causes very health impact. Purpose of this study was, determination of sonochemical technology for cyanide removal from aqueous solutions in the presence of hydrogen peroxide. In this study, a productive set of 500w power ultresoun waves with two frequencies 35 kHz and 130 kHz were used. Experiments were performed using different initial ratio CN-/H2O2 1/1, 1/3 and 1/5 and at initial cyanide concentrations varying from 2.5 to 75 mg/L. The effects of parameters such as pH, time and initial cyanide concentration on the sonochemical degradation have been studied. The results of the study showed that the maximom removal efficiency of cyanide was achieved 85% by sonochemical technology at frequency of 130 kHz, during of 90 min, at pH of 11, at initial cyanide concentration of 2.5 mg/l and with initial ratio of CN-/H2O2 1/5. it was also found the rates of cyanide degradation under different conditions were quite low, and also the rate of cyanide degradation was high at first but later substantially reduced. The efficiency of cyanide removal had direct relationship with pH, frequency, hydrogen peroxide concentration and time, and it had reverse relationship with cyanide concentration.