Decolorization of acid red B aqueous solution by positive and negative electrical discharge

We investigated the decolorization of acid red B in aqueous solution by atmospheric discharge. It was found that decolorization was significantly greater when the aqueous solution served as the cathode than when it served as the anode. Our investigation suggests that hydroxyl radicals could be a major factor for decolorization in the solution phase. An analysis of the energy transportation by charge carriers in the discharge processes revealed that the mean energy transported from positive ions to the aqueous cathode was considerably higher than that transported from electrons/negative ions to the aqueous anode, and this could probably have indirectly affected the decolorization. •The role of the positive ions in cathode process has been explained.•In cathode process, the decolorization of O and ozone was partly discussed.•The UV radiation intensity of UV lamp and air plasma was given.