Enzymatic Bioremediation of Dyes from Textile Industry Effluents

The use of synthetic dyes began in 1865 with the discoveries of researcher William Henry Perkin. Its production and use only grew due to the high demand of several industrial sectors, mainly textiles. At the same time, concerns about environmental problems arose due to the disposal of wastewater with dyes, being the textile industry’s effluents the most polluting in the world. According to their structure, dyes can be more or less harmful, whereby azo dyes are the most worrisome from an environmental point of view. Problems, such as carcinogenicity, mutagenicity, and genotoxicity, are related to dyes, as well as contamination of water, and soil, and damages to agricultural plantations. Some of the methods used in the treatment of textile industrial effluents are membrane filtration, coagulation, chemical oxidation, biodegradation, photocatalytic degradation, phytoremediation, and enzymatic remediation. Enzyme remediation is considered an efficient, ecological, and innovative technique, through which enzymes can be used in free or immobilized form. The main enzymes involved in the degradation of azo dyes are azoreductases, laccases, and peroxidases. In some cases, harmful by-products are formed during the reactions and require proper management. Thus, this chapter addresses the main aspects of enzymatic bioremediation of dyes present in effluents from the textile industry.