Biosorption technology for removal of metallic pollutants-An overview

Abstract

The main sources of metallic pollutants to the environment are the diffuse sources such as forests and agricultural soils as well as industrial and municipal wastes, which are either discharged directly or transported in to the environment. Various conventional technologies such as chemical precipitation, solvent extraction, ion exchange, membrane separation, electrochemical treatment etc. have been employed to remove metal pollutants from aqueous solution. The exploration of new technologies involves the removal of toxic metals from wastewater with the use of biological adsorption technology. The biosorption is the selective appropriate process for removal of metal ions uptake that may involve the contribution of diffusion, adsorption, chelation, complexation, coordination, or micro-precipitation mechanisms, depending on the specific substrate (biomass). In this overview, the use of the various low cost, easily available and eco-friendly biosorbents used for removal of metallic pollutants from contaminated water and their mechanism are discussed.