Study On Oxidation Degradation Of Oxganic Dye In Aqueous Solution By Ultrasound/Fenton

In the recent years, with the rapid development of petrochemical, plastic, synthetic fibre, printing and dyeing, water pollution becomes more and more severe, in which biorefractory poisonous organic pollutants occupy a large proportion. Therefore , environmental pollution has caught the attention of research fellows worldwide concerned. The treatment of water pollution which is one branch of environment protection always draws people's attention Scientists round the world try to find an effective means to deal with the poisonous orgnic waste water which is difficult to biorefractory and can cause cancer, monstrosity, and mutation. And this becomes a hotspot in the precaution of water pollution. Because the limitations of traditional method of sewage treatment, scientists put forword a measure to treat the bioefractory poisonous organic pollutants using advanced Oxidation Technology(AOTs) after a great deal of experiments. This method is considered a wide use prospect.In this paper, the sonochemical degradations of methyl violet , reactive-red in aqueous solution,chosen as models of basic dye, were studied. The effects of ultrasound for decomposition of methyl violet , reactive-red were investigated in homogenous system, The results indicated that decomposition process of methyl-violet and reactive -red follows apparent first-order reaction kinetics. The influence of several parameters such as the initial pH of the aqueous solution, the initial concentrations of the dye , reaction temperature of medium and catalyst Fe²⁺ on the ultrasonic decomposition of methyl violet and reactive-red was also investigated in this paper. It was found that the decomposition rate of methyl-violet is accretion with pH increasing when pH is from 3 to 10,the decomposition rate increases notability when pH vaule is smaller 3. The effect of pH vaule of aqueouse solution on decompoaition rate of reactive-red is obvious . The decompositions are relatively slow in the medium and acid condition. The degradation rate increased continuously with pH increasing under alkali conditions which shows that the reactive-red is easy to degrade under alkali conditions. The effects of initial concentration of aqueous solution on decompoaition rate of methyl violet and reactive-red are also obvious . The degradation rate decreased with increasing initial concentration.The effects of ultrasound/Fenton reagent process on the decomposition of methyl violet were also carried out ,and the quantity of OH radical was determined .we can find that the resultof degradation by ultrasound/ fenton 's reagent together is better than that of degradation respectively. Through the determined quantity of OH radical, It was found that The quantity of OH radical notability increases,which conforms with The practical decompositon of methyl violet and reactive-red using coupled ultrasound and Fenton's reagent. And OH radical is the key to degrade the methyl-violet and reactive-red from the relationship between the production of OH radical and the degradation of methyl-violet.