Ultrasonic Synergistic Expansion Graphite And Fenton Like Degradation Of Azo Dyes

In recent years,with the high-speed development of plastic,synthetic fiber,petrochemical and dyeing,water pollution become more and more serious.In which poisonous organic waste water is one of the most difficult to deal with because the unique features such as heavy color,difficult to be biodegrade and complex component.Environmental pollution has caught much attention world widely.As the most important branch of the environmental protection area,the treatment of waste water,especially the organic dying waste water,has been studied by more and more scientists.Due to the limitations of traditional crafts of sewage treatment,advanced oxidation technology(AOTs)had been put forward to degrade waste water during a great deal of experiments.This method is considered a widespread use prospect.A new method was studied for preparing sulfur-free exfoliated graphite by using a mixed solution of HClO4 and C2H5 COOH as intercalatant.The best conditions for preparing the exfoliated graphite were optimized by an orthogonal test method.Expandable graphite with 260ml/g expanded volume was obtained in the best conditions.The product was analyzed by the methods of SEM and IR.In this paper,two combination methods were used to degrade organic dying waste water,which acid black 210,acid yellow and weak acid blue 113 were selected as the research object.The effect factor,intermediate,mechanism and kinetics characteristics of degradation,was studied by UV-via spectroscopy.In this paper,the ultrasound degradation of acid black 210,acid light yellow and weak acid blue 113 in aqueous solution,were chosen as basic dye model.The effects of ultrasound to the dying solutions were investigated in homogenous system.The results indicated that decomposition process of the three organic dying solutions follow first-order reaction kinetics.The process of ultrasound-Fenton like reagent(US/Fenton-like)degrading organic dying waste water was studied too.It can be obviously find that the result of degradation by US/Fenton-like reagent together is better than both one of degradation methods respectively.In the experiments of single factor effect,the effect factors of degradation,such as dosage of expanded graphite,ultrasonic power,pH value of dying solution,catalyst addition,werestudied.The best reaction conditions were reached when the pH of initial dying solutions.It was found that the decomposition rate of the three azo dyes reaches maximum when pH is 3.Under the best condition of target dying pollutions degradation obtained by experiments,the degradation rate of acid black 210,acid light yellow and weak acid blue can be 99.92%,99.89 and 99.65%.