An Overview of Effluent Treatment for the Removal of Pollutant Dyes

Wastewater effluents from textile, paper, tannery and beverage industries are contaminated with variety of pollutants including dyes. Dyes are skin irritant, carcinogenic and can cause allergic dermatitis and mutation. Environmental legislations are now becoming more stringent to control the release of dyes into the environment. Biological treatment of effluent requires a large land area and is constrained by toxicity of some chemicals, and less flexibility in design and operation. Chemical treatments for the removal of dyes from the polluted effluents are not cost effective. Photocatalytic dye degradation techniques suffer from their low efficiency. Adsorption method has been found to be efficient, economical, renewable and eco-friendly solution in treating effluents contaminated with dyes. An overview of the treatments of dye contaminated effluents by biological, chemical and physical methods have been presented.