Decolorization of different reactive dye wastewaters by O3 and O3/ultrasound alternatives depending on different working parameters

Abstract

The removal of the color of dye from wastewaters is one of the main problems of the textile industry for both colorists and manufacturers. In this study, ozone gas was used to decolorize the reactive dye effluents. Nine commercial dyes were used for preparing the reactive dye effluents. These dyes have different three anchors (monochlorotriazine, vinylsulphone, monochlorotriazine-vinylsulphone) and three chromophore groups (monoazo, diazo, azo-cu). Thus, in this study, the effect of ozone treatments was investigated on the decolorization efficiency of dyes having different chromophore and anchor groups. In addition, the effect of ozone on the decolorization efficiency depending on the presence of ultrasound energy and dyeing auxiliaries was studied. The results showed that ozonation treatment was an effective method for the decolorization of reactive dye effluents and, generally, the presence of ultrasound had generally positive effect on the efficiency of decolorization.