مقايسه كارايي فرآيند سونوشيميايي و فرآيند تركيبي سونوشيميايي با پراكسيد هيدروژن در حذف سيانيد از محيط هاي آبي

Comparison efficiency of both sonochemical and sonochemical/hydrogen peroxide processes for cyanide removal from aqueous solutions

Background and purpose: Cyanide is a species of high toxicity that is found mostly in industrial effluents such as electroplating, metal mining, metallurgy and metal cleaning processes. Entrance of it to existing environment contains a hazardous to health. The purpose of this study was to compare efficiency of both sonochemical and sonochemical / hydrogen peroxide processes for cyanide removal from aqueous solutions. Materials and methods: This study has been used from a productive set of 500w power ultrasound waves in of two frequencies 35 kHz and 130 kHz. Experiments were performed with different initial ratio 1/1, 1/3 and 1/5 and at initial cyanide concentrations varying from 2.5 to 75 mg/L. in this study, Effects of parameters such as pH; time, initial cyanide concentration, hydrogen peroxide/ cyanide and frequency on removal efficiency of mention processes have been studied. Results: The results of the study showed that the maximum removal efficiency of cyanide had been achieved to 74% by sonochemical process at frequency of 130 kHz, at time of 90 min, at pH of 11, at initial cyanide concentration of 2.5 mg/1 and with initial ratio (jjjf) of 1/5. However in similar condition, removal efficiency of cyanide had been achieved to 85% by sonochemical/ hydrogen peroxide process. Conclusion: The results of the study showed that 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. Results of the study showed that efficiency of sonochemical/hydrogen peroxide process is more than of sonochemical process for cyanide removal from aqueous solutions. Also removal efficiency of cyanide has direct relationship with pH, frequency, hydrogen peroxide and time; however, it has reverse relationship with cyanide concentration for process.