Experimental Study On Degradation Of Methyl Violet In An Ultrasound-magnesium Collaborative System

In recent years, ultrasonic cavitation treatment refractory organic pollutants in water have been attracted by experts all over the world. Ultrasound as a clean energy, not only can improve reaction conditions for promote the REDOX reaction, but also can be to achieve the difficult degradation of organic pollutants reaction.Printing and dyeing wastewater(PDW) has been caused a serious burden for water environment. It has large amount of discharge, high level of color, complicated components,non-biodegradability and high concentration. Methyl violet is mainly used as acrylic, cotton,silk and wool fiber dyeing, which belongs to triphenylmethane dyes. According to the research, the activation energy of triphenylmethane dyes can be higher than azo dye, it is difficult to remove by traditional processing techniques. Therefore, to find a convenient and effective treatment have to be settled urgently.The effects of ultrasonic-magnesium system on decolorization rate and degradation mechanism efficiency of methyl violet were studied. Use of ultrasonic-magnesium united technology, needle-plate high voltage pulse discharge technology and Fenton oxidation to degradation of methyl violet, to find the optimum treatment process. Methyl violet decolorization rate and COD removal use of spectrophotometric assay and potassium dichromate.(1) The optimum experimental condition in the ultrasonic-magnesium system was found out by changing initial concentration, magnesium added amounts, reaction time, p H value and ultrasonic frequency. The results indicated that the ultrasonic-magnesium system was better than ultrasonic alone, the former decolorization rate and COD removal was increased by 76.81% and 75.41% respectively. It is most favorable to degradation of methyl violet when the original concentration was 5.16×10-3mol/L, magnesium dosage was 2.0g/L, p H value was 3.50, ultrasonic frequency was 40 k Hz and reaction time was 60 minutes,decolorization rate and COD removal was reached 94.98% and 92.77% respectively.(2) Using the optimum conditions of ultrasonic-magnesium united technology,needle-plate high voltage pulse discharge technology and Fenton oxidation to deal withmethyl violet of the original concentration was 5.16×10-3mol/L. Research shows,decolorization rate and COD removal of methyl violet was reached 94.98% and 92.77%respectively by ultrasonic-magnesium system. In needle- plate pulse plasma discharge, the highest decolorization rate was 91%. Deal with the same original concentration of methyl violet wastewater with Fenton oxidation, by orthogonal experiment, methyl violet decolorization rate was only 19.49%. While under the optimum process conditions, the best methyl violet decolorization rate was 77.66%. From the treatment effect of methyl violet decolorization to determine of ultrasonic-magnesium combined technology is the optimum treatment process, with simple operation, cheap and has plenty of potential.