Treatment of Azo Dye-Containing Wastewater Using Integrated Processes

Abstract

Azo dyes are the most widely used dyes in textile industry. During the dyeing process, the degree of exhaustion of dyes is never complete, resulting in azo dye-containing effluents. The biodegradation of azo dyes is difficult due to their complex structure and synthetic nature. The removal of azo dyes from industry effluents is desirable not only for aesthetic reasons but also because azo dyes and their breakdown products are toxic to aquatic life and mutagenic to humans. In recent years, application of integrated processes for treatment of azo dye-containing wastewater has received considerable attention in the literatures. This review highlights some of the notable examples in the use of integrated processes for azo dye-containing wastewater treatment and deals with biodegradation mechanism of azo dyes. The review also summarizes and attempts to compare the advantages and disadvantages of integrated processes. It can be found that integrated treatment system seems to be an efficient and promising alternative for the treatment of azo dye-containing wastewater.