IIT-Guwahati scientists develop eco-friendly solution to remove lead from contaminated water

Researchers at Indian Institute of Technology (IIT), Guwahati have developed a natural method to remove lead from contaminated water using cyanobacteria, microorganisms that are related to bacteria but are capable of photosynthesis, according to officials.

The developed method offers a sustainable and low-cost solution to one of the world's most persistent environmental threats, they added.

The findings of this research have been published in the prestigious Journal of Hazardous Materials.

According to Debasish Das, Professor, Department of Bioscience and Bioengineering, on a global level, lead is one of the most toxic pollutants, affecting over 800 million children —approximately 275 million in India itself.

"It commonly enters water through industrial discharge, agricultural runoff, and old water pipelines. Once a water resource is contaminated with lead, it remains for decades, accumulating in living organisms and causing severe neurological, cardiovascular, kidney, and developmental problems. Conventional methods, such as chemical treatment and synthetic adsorbents used for removing lead, are generally expensive and often generate secondary pollutants," he said.

To address these challenges, "we used bioremediation, a natural process in which microorganisms clean contaminated environments", Das added.

"These microorganisms naturally exist in soil and water and help in restoring ecological balance. The team researched the different parts of the cyanobacterium to examine which of the components were the most efficient to absorb and remove the lead contaminants," he said.

As a result, the study found that exopolysaccharides, or EPS, a part of the cyanobacterium, exhibited the highest lead removal efficiency of 92.5 pc from contaminated water.

"These cyanobacterial biosorbents require minimal energy input and can be scaled without sophisticated infrastructure, making them more affordable for widespread application.

"Preliminary estimates suggest that the overall cost of treatment using our method is approximately 40–60 pc lower than that of conventional techniques, while maintaining comparable or even superior efficiency in metal removal," he added.

This economic advantage, coupled with its eco-friendly nature, positions our approach as a sustainable alternative for industries and municipalities seeking affordable solutions to contamination, Das said.