Blue-Green Algae Can Remove Lead from Water

Why in News?

Recently, scientists at the IIT Guwahati have developed a biological material using cyanobacteria (blue-green algae) that can remove lead from contaminated water.

• Cyanobacteria (blue‑green algae) – Commonly found in ponds, lakes, reservoirs, paddy fields, and slow‑moving fresh water bodies.
• Material – Exopolysaccharides (EPS), a sticky, sugar‑rich substance secreted by algae.
• EPS Mechanism – Blue‑green algae grow in ponds or paddy fields; their cells secrete sticky, sugar‑rich EPS molecules that naturally bind lead.
• Algae further adjust their composition to trap and hold lead particles.
• Efficiency – EPS can remove 66.2% of lead, one of the most toxic heavy metals present in water.
• Additional Benefits – Cyanobacteria form cyanolichens with fungi, enrich soil, fix nitrogen as a natural biofertiliser, and boost agricultural productivity.
• Conventional Methods – Traditional methods like chemical precipitation, membrane filtration, and ion exchange are costly, energy‑intensive, and polluting.
• Biological approaches offer greener, renewable, and eco‑friendly alternatives.

Reference 

The Hindu |  Blue-green algae can remove lead from water