IIT researchers develop product to recover fertilizers, water from urine

Researchers of the Indian Institute of Technology (IIT) have developed a prototype that can produce green fertilizers and water from human urine.

The product, 'Water Chakra', works on the development of a modular on-site toilet treatment unit. It recovers about 96 per cent of phosphorus and 85 per cent of nitrogen in the form of commercial grade ammonia solution and struvite fertiliser, besides recovery of 90 per cent water, according to researchers at the IIT Madras.

"The intention of 'Water Chakra' team was to develop an integrative modular on-site toilet-treatment system," Anusha Gupta, a PhD scholar at IIT Madras who led the team, said.

Gupta said the aim was to protect valuable water assets, reduce customer's operation costs and create new products from toilet resources (human urine) in a simplistic approach, adding that it could unlock the "circular economic potential in sanitation".

"The Water Chakra project aims to recover fertilizers and water from urine in India," Gupta said. "The developed prototype can be installed in large footprint areas like commercial complexes, corporate buildings, where huge amount of urine can be collected and used for processing to obtain green fertilizers and water."
Explaining the product's way of operation, Indumathi M Nambi, technical mentor at the IIT Madras, said: "Urinals are retrofitted to make water-less urinals in one of our buildings, which helps us to collect the concentrated urine that is stored in a primary storage tank in large volumes of up to 500 litres."
"This tank is followed by a hydrolysis tank where the urine is stored for three days for rise in pH to 9-10," Nambi said. "This hydrolyzed urine then gets pumped to the distillation column, where it gets in contact with steam generated using a steam generator."