Determination of Sonochemical Technology Efficiency for Cyanide Removal from Aqueous Solutions

Cyanide is a species of high toxicity that found mostly in industrial effluents such as electroplating, metal mining, metallurgy and metal cleaning processes. Entrance of it to existence environment contains very health hazardous. Objective of this study was the determination of efficiency of sonochemical technology for cyanide removal from aqueous solutions. In this study, it has been used from a productive set of 500w power ultrasound waves in of two frequencies 35 kHz and 130 kHz. Experiments were performed at initial cyanide concentrations varying from 2.5 to 75 mg/L. The effects of parameters such as frequency (35-135 kHz) and initial cyanide concentration (2.5-75), time (1590min), pH (3.5-11) on the sonochemical degradation were studied. The solution was irradiated for 15 min and then sonication was stopped for the next 10 min. This process was continued till the solution was irradiated for a predetermined time (15-90 min). The results of the study showed that the maximum removal efficiency of cyanide had been achieved 74% by sonochemical technology at frequency of 130 kHz, at time of 90 min, at pH of 11 and at initial cyanide concentration of 2.5 mg/l. The results of the study showed that the rates of cyanide degradation under different conditions had always been quite low and also the rate of cyanide degradation was first high but it was later substantially reduced. Also efficiency of cyanide removal had direct relationship with pH, frequency and time and it had reverse relationship with cyanide concentration for the process.