Harmful Impacts of Heavy Metals and Utility of Biosorption Technique for Their Removal from Wastewater: A Review

The increasing number of efluents discharged from the source of water (urban, industrial, agricultural etc.), is resulting in a higher concentration of heavy metals in the source. Heavy metals have a density of over 5g/cm3 to the metals. These are toxic, mutagenic, carcinogenic and resistant in watery and non-aquatic environments and impact water and non-water bodies seriously by substituting the basic metals of the same function. The extraction from the wastewater can be done in numerous techniques for example using an ion replacement, membrane filtration, osmosis, etc. This study discusses the adverse effects of heavy metals on the human body, the benefits of biosorption over traditional approaches for removal of heavy metals, the different biosorbents used to extract heavy metals and concerning issues regarding its commercial use, offering a wider viewpoint for the diversity of biosorbents and utilization of biosorption technique. It is evident from the profound literature survey that pH, biosorbent particle size, contact time, initial metal ion concentration, presence of chelating ligands etc. are some factors that affect the rate and extent of biosorption.