Effect of several reagents on decolorization of methyl orange solution with KIO_4

摘要

Increasing environmental pollution caused by toxic dyes due to their toxicity makes the removal of these dyes imperative. So, it is crucial to develop processes that can destroy these dyes effectively. It has been generally agreed that methyl orange (MO) solution can be effectively decolorized in KIO_4 homogeneous system under UV light irradiation. The knowledge on the influence of several reagents possesses both practical and theoretical values. The effects of H_2O_2, K_2S_2O_8, and KBrO_3 were investigated in detail. The results of the effects of five •OH scavengers are presented. The results show that S_2O_8~(2-) and BrO_3~- can promote the photocatalytic decolorization of MO solution and H_2O_2 can enhance the decolorization efficiency of MO in the dark. However, the results of the effects of five •OH scavengers cannot substantially support the argument that the degradation mechanism of KIO_4 involves hydroxyl radical attack. A more detailed mechanism needs to be further investigated in the near future.