Effectiveness of ozone in decolorization of reactive dye effluents depending on the dye chromophore

Abstract

In this study, ozonation process was used for decolorization of five commercial reactive dyes (Remazol Brilliant Red 3BS-A 150%, Remazol Yellow 3R-SA 133%, Remazol Blue R Special, Remazol Turquoise G 133% and Remazol Brilliant Blue BB), having various chromophore groups (monoazo, anthraquinone, phthalocyanine, formazan copper complex). The aim of the study was to examine in detail the effect of the major system parameters on the decolorization efficiency of ozone and to compare the effectiveness of ozone in decolorization of reactive dye effluents depending on the dye chromophore. The parameters, which were examined separately, are the solution pH and the ozonation time. Ozonation process was carried out in batch system and the ozone production rate was 1000 mg/h. In the study, it was found that color removal efficiencies, depending on the dye chromophore, vary from 83% to 96% and 34% to 93% in the ozonation processes carried out with and without pH adjustment, respectively. Furthermore, according to the experimental results, it can be concluded that the ozonation process could be effectively used in decolorization of reactive dyes especially having copper formazan and anthraquinone chromophores.