Research On Ultrasonic And Electrical Oxidation Degradation Of Azo Dyes Wastewater

Dyeing wastewater has the characteristics such as heavy color,complex organic composition,great biologic toxicity and inflexible degradability etc, dealing with this kind of wastewater by routine methods of chemical, physical or biochemical always wastes large cost but gets small effect. Exploring more economical treatment becomes the research hotspot of this field.Ultrasonic electrochemistry has the merits of accelerating and controlling electrochemistry reaction,changing reaction process and improving reaction conditions etc, it has been applied widely in fields of electrochemistry analysis,plating and organic synthesis, but the research for degradation of the organic composition of wastewater by ultrasonic electrochemistry method is still on experimental stage.In this paper, based on azo dye methyl orange as the research object, in NaCl and Na₂SO₄ electrolyte system, the research has been done respectively, which is about the influence of parameters such as ultrasonic power,electrical voltage and pH value etc on discoloration rate of methyl orange and removal rate of COD_Cr in ultrasonic electrochemical degradation; Combined UV spectrum and HPLC analysis method, preliminary discussion of the reactive principle and reactive dynamics of ultrasonic electrochemical degradation for methyl orange has been done, discoloration reaction accords with the first degree reactive dynamics model; On this basis, a kind of mobile ultrasonic electrochemical wastewater treatment device has been created, using this device, dyeing wastewater with initial concentration between 100 mg.L^-1 to 200 mg.L^-1 has been treated by uniform test method, the experimental results show that the efficiency of this device is high, discoloration rate of the first yielding water is over 90%, and under the best operation conditions, removal rate of COD_Cr of the second yielding water is over 90% too. Step by step regress analysis of the experimental data has been done with EXCEL software, and received the optimal mathematical model and technological conditions of this dyeing wastewater treatment device.In addition, in this paper, a kind of reagent prescription for fast-measuring COD_Cr by spectrophotometry has been developed, through experimental verification, the value of COD_Cr measured with self-made reagent kits has no difference from which measured with imported reagent kits.