Chapter 10 - Biosorbents for heavy metal removal from industrial effluents

Abstract

Introduction of various contaminants into natural water bodies causes adverse change in the quality of water system and aquatic life. These contaminants either originate as a by-product or waste from industrial sectors. These contaminants are rich source of heavy metals, pharmaceutical by-products, and organic contaminants. Direct release of these contaminants in the water bodies threatens aquatic life and ecosystem. Various conventional methods have been proposed so far for the removal of these contaminants from wastewater that includes membrane filtration, chemical precipitation, etc. The aforementioned methods are very expensive and generate large quantities of sludge and other toxic compounds that need careful disposal. Biosorption is an alternate and eco-friendly technique which uses natural products like agri wastes, microbial biomass to remove heavy metals from wastewater. These biosorbents contain various functional groups which entrap or bind with the metals present in the wastewater. Recent advancement in the field of science and technology has led to the designing of various bioreactors helpful in the effective removal of heavy metals and ions from large volumes of effluent water. This chapter reports the harmful effects of heavy metals on ecosystem, uses of various biosorbents for heavy metal removal, effect of modification and immobilization on efficiency of biosorbents, and various factors affecting biosorption process. Efforts have also been made to summarize the recent advances, future prospects, and current status of the biosorption processes.