COMPARISON OF DIFFERENT OXIDIZING AGENTS FOR TEXTILE WASTEWATER TREATMENT

Abstract

Worldwide, there is a continuous need to develop alternative treatment methods to replace conventional processes for textile wastewater. One such method is Fenton oxidation. It requires hydrogen peroxide (H₂O₂) and iron salt to produce hydroxyl radical (^•OH) with redox potential of 2.80eV as oxidizing agent.  However, there are few limitations of Fenton oxidation process such as sludge formation, acidic conditions, excessive amount of the Fenton’s reagents used and high cost of commercially available hydrogen peroxide (H₂O₂). These factors altogether make the process economically non-viable. One of the ways to solve this problem is to find some other oxidizing agents. In this study, comparison of different oxidizing agents with all aspects will be made for textile wastewater treatment in the light of various investigations. These oxidizing agents include ozone, sulfate radicals, holes, permanganate, hypochlorite, chlorine dioxide. This study confirms that ozonation is more suitable for decolorization and unlike hydroxyl radicals, sulfate radicals perform effectively in both acidic and alkaline conditions. However, permanganate, hypochlorite and chlorine dioxide can possibility be used in combination with conventional methods. Holes have high potential of 2.53eV and these can easily degrade organic compounds but its application is limited to low dye concentration. Therefore, based on this review it can be concluded that selective research is required for selection of suitable oxidizing agent because the efficiency of the aforementioned oxidizing agents depends on the application and characteristics of textile wastewater.