Science and Technology Roadmap for Adsorption of Metallic Contaminants from Aqueous Effluents Using Biopolymers and Its’ Derivatives

Large amount of heavy metal pollutants are discharging by industries which are hazardous for environment. Several metallic pollutants like copper (II), nickel (II), lead (II), cadmium (II), and zinc (II) introduced in water can cause serious threat to aquatic environment. Biopolymers are promising candidate for elimination of heavy metals from waste stream. In this chapter, biopolymers based on polysaccharides can be classified into four sub-categories: homopolymers, blends of polysaccharide, copolymers, and functionalized polysaccharide or their composites. Natural biopolymers like alginate,chitosan, cellulose, chitin, and starch contain numerous surface active groups which can act as binding agent to eliminate heavy metals from water. Introduction of secondary functional groups with biopolymers enhances its’ mechanical strength which is essential for recyclability of the adsorbent to ensure economical application of biopolymers for industrial scale waste water treatment plant. This chapter provides the in-depth mechanism of heavy metal interactions with the bio-polymeric surface using π-π, dipole–dipole reaction. Furthermore, it can go for hydrogen network, or weak Van-der-walls attraction with the co-polymers, homo-polymer, blending of polymers, as well as biopolymer/composite matrix containing negative ions or electron-enriched groups. The concluding part of the chapter illustrates the adsorptive behavior of cations using kinetics and isotherms analysis of the equilibrium system for waste water treatment.