Application of low-cost adsorbents for dye removal – A review

A variety of synthetic dyestuffs released by the textile industry pose a threat to environmental safety. Azo dyes account for the majority of all dyestuffs, produced because they are extensively used in the textile, paper, food, leather, cosmetics and pharmaceutical industries. Existing effluent treatment procedures are unable to remove recalcitrant azo dyes completely from effluents because of their color fastness, stability and resistance to degradation. Bacterial decolorization and degradation of azo dyes under certain environmental conditions has gained momentum as a method of treatment, as these are inexpensive, eco-friendly and can be applied to wide range of such dyes. This review mainly focuses on the different mechanisms of decolorization and discusses the effect of various physicochemical parameters on the dye removal efficiency of different bacteria. The enzymatic mechanisms involved in the bacterial degradation of azo dyes, the identification of metabolites by using various analytical techniques, and the nature of their toxicity has been investigated. This review provides an overview of bacterial decolorization/degradation of azo dyes and emphasizes the application of these processes for the treatment of azo dye-containing wastewaters.

Bacterial decolorization and degradation of azo dyes: a review.

Bacterial Decolorization and Degradation of Azo Dyes

Role of nanomaterials in water treatment applications: a review.

Adsorption of dyes by nanomaterials: Recent developments and adsorption mechanisms

Biological removal of dyes from effluents of textile and dyestuff manufacturing industry offers some distinct advantages over the commonly used chemicals and physicochemical methods. These include possible mineralization of the dyes to harmless inorganic compounds like carbon dioxide and water, and formation of a lesser quantity of relatively harmless sludge. Removal of dyes from these wastewaters has been reviewed with respect to biological decolorization as well as complete biodegradation of the dye molecules. Emerging techniques with reference to biological treatment of these wastewaters have been discussed under aerobic, anaerobic, and combined anaerobic–aerobic systems. Advantages and limitations of different biological methods have been highlighted, and future studies to establish these techniques for their applications on industrial scale have been suggested.

Removal of Dyes from the Effluent of Textile and Dyestuff Manufacturing Industry: A Review of Emerging Techniques With Reference to Biological Treatment

T. K. Bansal

Papers

Removal of Dyes from the Effluent of Textile and Dyestuff Manufacturing Industry: A Review of Emerging Techniques With Reference to Biological Treatment

Decolorization of triphenylmethane dye-bath effluent in an integrated two-stage anaerobic reactor