Researchers at the Indian Institute of Technology (IIT)-Guwahati have discovered a smart, cost-effective way to clean industrial wastewater using fruit waste. This innovative method can remove harmful pollutants in just five minutes and can be reused multiple times, making it both practical and sustainable.

The research team, led by Professor Gopal Das from the Department of Chemistry, has shown how waste materials like pineapple crowns and mosambi (sweet lime) fibers can be transformed into biochar – a carbon-rich material that helps absorb harmful chemicals from wastewater.

Their findings, published in the journal Chemical Engineering Science, focus on removing nitroaromatic compounds – dangerous chemicals found in wastewater from industries like dyes, pharmaceuticals, pesticides, and cosmetics.

According to Professor Das, nitroaromatic compounds can harm both human health and the environment.

“These chemicals are widely used in various industrial applications, but their continuous discharge into water bodies leads to severe pollution. Once in the environment, they persist for long periods, accumulating in aquatic systems and affecting both marine life and human populations,” he explained.

These compounds can cause serious health issues, including cancer, genetic mutations, and toxicity. However, existing treatment methods often require expensive materials and equipment, making them less accessible for widespread use.

To address these challenges, the IIT-Guwahati team explored the potential of biochar, which is produced by heating organic waste materials in the absence of oxygen – a process called pyrolysis. They used pineapple crowns and mosambi fibers, which are usually discarded as waste, to create two types of biochar:

  • ACBC (Ananas Comosus Biochar)

  • MFBC (Citrus Limetta Biochar

The team tested these biochars and found that they effectively removed 4-nitrophenol, a hazardous nitroaromatic compound, from industrial wastewater.

“This method enhances both efficiency and practicality for large-scale applications by significantly reducing the time needed for pollutant removal,” said Das.

A Reusable, Eco-Friendly Solution

One of the standout features of this method is that the biochar can be reused multiple times without losing its effectiveness. This makes it both sustainable and affordable for industries.

“Both ACBC and MFBC retained their high performance over multiple cycles. This feature makes the approach not only sustainable but also economically viable for industries looking for long-term wastewater treatment solutions,” Das added.

Promoting a Circular Economy

The researchers believe that this method could help reduce waste and promote a circular economy. By turning fruit waste into a valuable resource, they aim to tackle both pollution and waste management at the same time.

“This work demonstrates how waste materials can be transformed into valuable resources for environmental protection. By using fruit waste to tackle industrial pollution, we are not only addressing water contamination but also promoting a circular economy approach to waste management,” Das said.

The potential of this biochar-based method extends beyond industrial wastewater treatment. It could be used to purify drinking water in rural areas or to restore polluted water bodies and improve soil quality in regions affected by industrial discharge.

“The same technology could also be applied to environmental remediation efforts, helping restore polluted water bodies and improve soil quality,” Das explained.

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