ABSTRACT
Azo dyes are widely used in textile, paper, food and the pharmaceutical industry. Azo dyes present in textile effluent are a major environmental concern. Their toxicity is due to the presence of a nitro group which is mutagenic in nature, and after breakdown, they generate toxic products such as 1, 4-phenylenediamine, o-tolidine. Wastewater contaminated with azo dyes is treated using various physical and chemical purification methods, including advanced oxidation processes. In recent decades, biological degradation of dye has gained interest mainly for its minimum energy consumption, effectiveness, safety and eco-friendliness. In this chapter, biodegradation of azo dye using various microorganisms has been discussed. Moreover, the development of innovative nanotechnology coupled with the conventional biological process has been analyzed for the treatment of textile wastewater. Reactors used and recent advancements in bioremediation are presented. Furthermore, limitation and future scope of degradation of azo dyes were also examined.
