Decomposition of a Diazo Dye in Aqueous Solutions by KMnO4 /UV/H2O2 ‎Process

T ‎ his study examined the photolytic ‎degradation of C.I. Acid Red ‎‎73(AR73), in aqueous solution by ‎KMnO4/UV/H2O2 process. A ‎continuous circulated photoreactor ‎equipped with a UV lamp was ‎used. (I) Potassium permanganate ‎was used for decolourisation of ‎AR73 dye solution. The ‎stoichiometric amount of ‎potassium permanganate required ‎for 1 mol of AR73 complete color ‎removal was determined (2.79 ‎mol). In the acidic solution, 100% ‎of AR73 color removal and near ‎‎10% dye mineralization have been ‎observed in no more than 5 ‎minutes. (II) After decolourisation ‎period, UV/H2O2 system was ‎applied for mineralization of the ‎dye solution. Under the best ‎operational conditions, after 180 ‎minutes of UV irradiation, 90% of ‎dye mineralization was observed. ‎III) The results of this method were ‎compared with those of obtained ‎by using UV/H2O2 system (without ‎KMnO4). It was found that within ‎the same irradiation time, ‎KMnO4/UV/H2O2 process is about ‎‎10% more effective for ‎mineralization of AR73 dye ‎solution. Prog. Color Colorants ‎Coat. 5(2012), 41-46. © Institute ‎for Color Science and Technology.‎