Sonolytic Decolorization of Textile Wastewater Containing a Mixture of Reactive, Acid and Disperse Dyes

The effect of chemical additives in combination with ultrasonication (US) was evaluated for the decolorization of simulated synthetic textile wastewaters containing Reactive Black 5 (RB5), Congo Red (CR), and Disperse Blue 3 (DB3). Maximum decolorization of 93% was achieved for the wastewater containing RB5 (50 mg L-1) at 8h sonication time and US power density of 1 W mL(-1). Persulfate (PS) assisted US was appeared to be better over the sodium sulfate (SS)-assisted US, giving 87.51% decolorization efficiency for the textile wastewater containing all the three dyes together (200 mg L-1) at a PS dosage of 1500 mg L-1 and the sonication time of 120 min. The rate of sonolytic decolorization followed first-order kinetics for the textile wastewater containing RB5 and CR. The results of this study indicate that, with an increase in the sonication time, the decolorization efficiency increases for the textile wastewater containing RB5 and CR, but decreases for that containing DB3.