IIT Guwahati researchers develop new method to remove ammonium from wastewater

Guwahati: Researchers from the Indian Institute of Technology (IIT) Guwahati have developed a groundbreaking method to remove ammonium from wastewater by using a combination of microalgae and bacteria.

The approach not only offers a sustainable solution but also drastically cuts down on energy consumption compared to traditional wastewater treatment methods, said the team led by Prof. Kannan Pakshirajan at IIT Guwahati.

Ammonium in wastewater, derived from sources like domestic sewage, industrial waste, agricultural runoff, and landfills, poses serious environmental and health risks.

It can lead to harmful algal blooms, increased water acidity, and oxygen depletion in aquatic ecosystems. Traditional ammonium removal methods involve oxygenation, which accounts for up to 90 per cent of a treatment plant’s energy consumption.

Pakshirajan’s team designed a photo-sequencing batch reactor (PSBR), where microalgae produce oxygen during photosynthesis, which is then utilised by nitrifying bacteria to convert ammonium into nitrate, followed by denitrification under anoxic condition using denitrifying bacteria to form nitrogen as the end product.

This eliminates the need for external oxygen aeration, making the process significantly more energy-efficient.

“Our system offers a sustainable solution for treating wastewater while cutting down on energy costs. By harnessing the oxygen naturally produced by microalgae, we can make the process not only more efficient but also highly cost-effective,” said Pakshirajan, Department of Bioscience and Bioengineering, IIT Guwahati.

The research, published in the prestigious Chemical Engineering Journal, combines scientific modelling with real-world data to ensure high ammonium removal rates under various conditions. The system demonstrated an energy savings of up to 91.33 per cent in comparison to conventional aeration methods used in wastewater treatment plants, making it an eco-friendly and cost-effective alternative.

This innovative method marks a significant step forward in sustainable wastewater treatment, offering practical applications for reducing the environmental impact of wastewater across industries.

IANS