Application of Agricultural Wastes as Natural Adsorbent for Removal of Industrial Dyes

Dyes are complex organic compounds which are used by various industries to color their products. The effluents of these industries are the main source of dye discharge to surface and underground waters and cuase their pollution. Today, color removal from wastewaters has been a matter of concern, both in the aesthetic sense and health point of view. Different methods have been used for dye removal from wastewaters but among them adsorption is introduced as an ideal alternative to other expensive treatment processes. In recent years, many researches have been done on successful application of different agricultural wastes as cheap biosorbents to remove different pollutants specially dyes. In this review paper, use of different agricultural wastes in removal of industrial dyes anionic, cationic, and nonionic dyes is evaluated. As adsorption capacity of biosorbents are dependent on different conditions, an overall study is conducted on effect of different operational parameters such as, pH, initial dye concentration, adsorbent dosage, and temperature on adsorption efficiency. Application of different kinetic models and adsorption isotherms for a wide range of biosorbents are also reviewed. Dye bearing waste treatment by adsorptive treatment using low cost alternative adsorbent is a demanding area as it has double benefits i.e. water treatment and waste management which makes this study very important.