Effects of Oxidants and Metal Ions on the Photochemical Reaction of Congo Red

Under the UV-light, effects of oxidants and metal ions on the photochemical reaction of congo red were studied by static method. The results showed that the effects of oxidants on the photochemical reaction of congo red were bigger than that of metal ions. The sequence of their accelerating degradation was KIO_4K_2S_2O_8KBrO_3H_2O_2, and that of accelerating decolorization was KIO_4K_2S_2O_8≈KBrO_3H_2O_2. Fe~(2+)/Cu~(2+)/Al~(3+)/Y~(3+)/La~(3+) easily formed coordination compounds with congo red, Mn~(2+)/Zn~(2+) slightly accelerated the photochemical decolorization of congo red and their extents were similar. HO·may be an important factor to cause photochemical decolorization of congo red.