ABSTRACT
Industries, such as textile, pharmaceutical, leather, cosmetics, and foods are large consumers of azo dyes, which are synthetic compounds that have ≥1 azo groups (–N = N–), which constitute the bonds between the organic residues aromatic nucleus. Based on the process and the amount of raw dye material used, a significant amount of dye wastewater is released from these industries that require adequate treatment to avoid the subsequent harmful effects on humans and the environment. There are a lot of conventional treatment methods available in the physicochemical and biological fields. Often the physicochemical processes have disadvantages, such as high energy consumption and the production of secondary toxic sludge, which means that they are not environmentally friendly and are less economic. In contrast, the bioremediation of azo dyes, which is treatment with biological agents, such as bacteria, fungi, algae, or any other living agent is feasible to mainly do not produce any toxic secondary intermediates via complete mineralization, and they are cost-effective. Therefore, they are a cost-effective alternative to physicochemical processes. This chapter will emphasize the use of biological agents for the treatment of azo dyes, the functional mechanisms, and various factors that influence the process for the removal of the dye content from wastewater.
