Background: Patents reveal that heavy metals are natural constituents of the earth's crust, but
some heavy metals like cadmium, lead, mercury, arsenic etc. are injurious to living organisms at higher
concentration. Nowadays, anthropogenic activities have altered geochemical cycles and biochemical
balance of heavy metals. Biomolecules are used nowadays for removal of heavy metals compared to
other synthetic biosorbents due to their environmental friendly nature and cost effectiveness.
Objective: The goal of this work is to identify the role of biomolecules like polysaccharides, polypeptides,
natural compounds containing aromatic acid etc. for heavy metal removal by bio sorption.
Discussion: It has been observed that efficiency of biomolecules can be increased by functionalization
e.g. cellulose functionalization with EDTA, chitosan with sulphur groups, alginate with carboxyl/
hydroxyl group etc. It was found that the porous structure of aerogel beads improves both sorption
and kinetic properties of the material. Out of polypeptides metallothionein has been widely used for removal
of heavy metal up to 88% from seawater after a single centrifugation.
Conclusion: These cost effective functionalized biomolecules are significantly used for remediation of
heavy metals by immobilizing these biomolecules onto materials.