Decolorization of Reactive Dyes from Textile Wastewater by Advanced Oxidation Methods

Abstract

The decolorization of Reactive Orange 16 and Reactive Black 5 by using different methods is studied. We utilize an ultrasonic homogenizer at two different frequencies and an ozonizer at two different flow rates for realizing the single, consecutive, and compound techniques. We study the processes for pH values of 2,7, and 10. Among the single methods, it is found that the most effective one is the ozonisation method providing a 98% decolorization for both dyes in 50 minutes. In the consecutive method, the treatment begins with the ultrasonic homogenizer, continues with the ozonizer, and ends with the ultrasonic homogenizer. This method yields a decolorization of 87% and 100% for Reactive Orange 16 and Reactive Black 5, respectively. Finally, the compound method, which is the simultaneous application of the ultrasonic homogenizer and the ozonizer, is used and resulted in a decolorization of 99% and 100%, respectively.

In addition to these methods, we utilize a physical absorption method for these dyes by using different absorbents. Among the analysed absorbents, the most effective one is active carbon and it results in 100% decolorization. Besides, corn silk, coconut crust, plastic waste, and car wheel wastes are shown to exhibit an insufficient performance for the decolorization process, but to be promising for pre-treatment applications.