Decolorization of Azo Dyes C.I.Acid Yellow 17 and C.I.Direct Red 31 by Dielectric-Barrier Discharge Air Plasma

In this paper, dielectric-barrier discharge plasma was applied to the decolorization and degradation of the azo dyes C.I.Acid Yellow 17 and C.I.Direct Red 31. The experimental results have shown that the decolorization and degradation percentage increases with rising applied voltages and current intensity and decreasing air-gap distances. When the air-gap distances were 4 mm and the voltage was 17 kV, the decolorization and degradation percentages went up to 100% and 91% in 180 s, respectively. Operations under optimum condition also had higher treatment efficiency after about two more minutes of treatment. Time extension after treatment could also lead to the rise of decolorization and degradation percentages.