Role of reactive intermediates in the radiolytic degradation of Acid Red 1 in aqueous solution

The role of reactive intermediates of water radiolysis (e(aq)(-), H-center dot, HO center dot. O-2(center dot-)/HO2 center dot) in decoloration and mineralization of aqueous solutions of Acid Red I dye was investigated. The decoloration is highly effective in the reactions of e(aq)(-) and H-center dot, and less effective in HO center dot reactions. The O-2(center dot-)/HO2 center dot pair does not take part in decoloration. For mineralization, which is an oxidative degradation, HO center dot radicals are needed: the efficiency increases with the dissolved oxygen concentration. The reactions of the O-2(center dot-)/HO2 center dot radical pair slightly increase the rate of mineralization. Iron and copper ions (possible constituents of waste waters) in low concentration do not influence the reactions. (C) 2008 Elsevier Ltd. All rights reserved.