Natural Polymers as Environmental Friendly Adsorbents for Organic Pollutants such as Dyes Removal from Colored Wastewater

Natural polymers are unique materials due to inexpensive, easily available, reproducible sources, hydrophilic and stable biopolymers, safe and devoid of side effects and flexible polymers. In addition, they have excellent adsorption specifications to remove pollutants including dyes from colored wastewater. Adsorption is a preferred method compared to other methods due to its fast and comfortable and inscrutable to toxic contaminants. The natural polymers also have excellent properties such as low initial cost, production of nontoxic by-products, relatively simple design and productivity in time. Properties of an ideal and suitable absorbent for removal dye include the following: extensive surface, high capacity and ability to absorb, the pores with appropriate size and volume, comfortable accessible, efficient, economical, high mechanical stability, compatibility, easy regenerable, environmental friendly, high selectivity to elimination various dyes and needless of high processing techniques. Therefore, researchers have lately centralized on expanding compounds based on natural polymers. The current review provides information about the application of natural polymers as adsorbents to remove dyes from colored wastewater. Also, some useful information about the influence of dye removal process variables, dye adsorption mechanism, adsorption isotherms, kinetics, and thermodynamics are presented.