IIT-Guwahati turns fruit waste into powerful water purifier

Researchers at the Indian Institute of Technology (IIT) Guwahati have developed a low-cost and sustainable method to remove hazardous pollutants from industrial wastewater using biochar derived from fruit waste.

The technique, which can eliminate contaminants within five minutes and be reused multiple times, could offer industries a viable alternative to conventional treatment processes.

The research, led by Professor Gopal Das from the Department of Chemistry, focuses on nitroaromatic compounds—dangerous pollutants found in wastewater from the dye, pharmaceutical, pesticide, and cosmetic industries. “These chemicals persist in water bodies, causing severe pollution and posing health risks, including toxicity, cancer, and genetic mutations,” Das explained.

The IIT-Guwahati team developed biochar from commonly discarded fruit waste, specifically pineapple crowns and mosambi (sweet lime) fibres, using pyrolysis—a process that involves heating organic material in the absence of oxygen. The resulting biochars, named ACBC (Ananas Comosus Biochar) and MFBC (Citrus Limetta Biochar), proved highly effective in absorbing 4-nitrophenol, a widespread nitroaromatic pollutant.

Compared to existing treatment methods, such as catalytic degradation and electrochemical processes, which often require expensive catalysts and complex setups, the biochar method is cost-efficient, simple, and environmentally friendly. “This work demonstrates how waste materials can be transformed into valuable resources for environmental protection,” Das said.

A key advantage of the biochar technique is its recyclability. “Both ACBC and MFBC retained their high performance over multiple cycles, making the approach not only sustainable but also economically viable,” he added.

The study, co-authored by research scholar Neha Gautam and Deepmoni Deka, Senior Technical Officer at IIT-Guwahati’s Centre for the Environment, was published in Chemical Engineering Science.

Beyond industrial wastewater treatment, the researchers believe the method could be integrated into rural water purification systems to remove organic contaminants from drinking water. It could also play a role in environmental remediation efforts to restore polluted water bodies and improve soil quality in affected areas.

Next steps for the research include lab-scale testing, field trials, and market validation before moving towards commercial production. If successful, this innovation could provide an affordable, scalable solution to one of the most pressing environmental challenges. (PTI)