Sustainable decolouration of dyes from effluent: A review

Abstract

Dyes are natural or synthetic organic compounds which are used for coloring different products and materials. Many industries such as leather, paper, plastic, textiles use dyes in many of their processing operations. Among various industries, textiles ranks first in extensively using dyes for colouring materials such as fibres, yarns and fabrics. Dyes are considered as a most harmful environmental pollutant because a very small amount of dye in water changes its appearance, colour and taste. The presence of dye in effluent accelerates environmental problems, disturbs aquatic life and also destroys water quality. There are various conventional and traditional techniques used by many industries for removing dyes from effluents but due to the generation of huge amount of sludge and their high cost. The main constraints for their use are these processes are less economic and efficient. The present review highlights the various sustainable processes and techniques which utilizes low cost, recycled and ecofriendly materials for decolourising dyes from effluent.