Bioreduction of Hexavalent Chromium Using Microalgae

Hexavalent chromium (Cr(VI)) is enriched in the water system of environment above the regulatory level due to different human activities. Cr(VI) has the chemical properties favorable for its dissolution in the water environment at an elevated concentration level. This concerns the environmentalists as Cr(VI) in water is carcinogenic to different organs of the living organisms. Different techniques like chemical, biological, and combination of both have been undertaken using various methods to remove Cr(VI) from the water. Primarily bioremediation including bioreduction and biosorption has potential to remove Cr(VI) from water. Also some other processes like microbial fuel cells and biostimulation sideline the Cr(VI) removal from water along with different primary objectives. Among the living organism, microalgae have great potential to remove Cr(VI) from water. They have the unique photosynthesis and cellular metabolisms compensating the Cr(VI) removal. The use of microalgae in bioremediation for removal of pollutants from the contaminated water is a practical interest due to different advantages as it requires low energy with reduced sludge formation and carbon dioxide sequestration. Most of the algae follow an adsorption followed by reduction of Cr(VI) during the bioremediation process.