IIT-M student designs system to recycle urine

Retrofits urinals to collect and process excreta into useful raw materials

Indian Institute of Technology, Madras

A student specialising in environmental engineering at the Indian Institute of Technology Madras has come up with a method to recycle human urine. Project Water Chakra won the Indian Innovation Growth Programme 2.0 award in July.

Anusha Ganta, a second year Ph.D student of the Civil Engineering Department, along with three project staff and her mentors Indumati Nambi and Divyapriya, a post-doctoral fellow, has retrofitted urinals on the campus to collect urine, that is then processed into several useful materials for use in manufacturing.

The concentrated urine is stored for three days to allow the urea to get converted to ammonia. By a process of steam distillation, the ammonia is segregated and this commercial grade liquid can be used to make cleaning products, such as detergents or in rubber manufacturing, Ms. Ganta said.

Magnesium is added to the rest of the liquid to precipitate phosphorous through a struvite process.

90% of water

“Through electrochemical process we can recover 90% of water and it can be used for gardening purposes and flushing,” she said.

“Right now, from 50 litres of urine we get 150 to 200 g of phosphorous. We developed a prototype for the Carbon Zero Challenge and with that we had applied for India Innovation Growth Programme 2.0,” Ms. Ganta said. The prize money of ₹10 lakh would be used to register it as a start-up to develop a compacted version of the prototype.