Surat: SVNIT to produce potable water from astronaut's urine

How does one recover potable water from human urine in a zero-gravity environment in space? This crucial question is being addressed by scientists at Surat's Sardar Vallabhbhai National Institute of Technology's (SVNIT) department of chemical engineering.

The varsity bagged the important Isro-sponsored project which is crucial in showcasing India's indigenous capability to undertake long-term human space flight missions.

India will attempt a human space flight with Gaganyaan, beginning 2023, the fourth nation in the world to attempt a long-term manned space mission.

At SVNIT, Surat, a team of chemical engineers explained that hauling tonnes of water during orbit or to a space station is inefficient and costly. This is why water recycling makes more sense.

The team comprising principal investigator leader Dr Alka Mungray, her husband Dr Arvind Mungray, Dr Shriram Sonawane and Asfak Patel - is developing a prototype of a briefcase-sized urine recycling system for this purpose.

The system will separate potable water and concentrated nutrient stream from human urine during space missions. At the heart of the system will be fluids made of thermal sensitive nanoparticles or nanofluids.

Researchers calculated that for a 30-month-long mission, each crew member will require 2,250 litres of water and 1,359kg of food to produce 1,493 litres of urine in that same period of time.

The research, sources at the Ahmedabad-based Isro's space applications centre (SAC) said, gathered steam after China's Tianhe space station core module recycled 66 litres of urine and treated it into distilled water to help the crew in July 2021.

The current urine recycling systems operational in international space stations (ISS) are very bulky, complicated, require a lot of maintenance and costly.

Also, the rejected urine streams are yet not recycled fully. Therefore, our team has proposed a solution which will reduce the overall weight, size, and complexity of the recycling system," said Dr Arvind Mungray, adding that it will lead to lower maintenance and overall cost.

The system requires specific membranes and reactors which have been tested and have been patented by the SVNIT laboratory. Human urine consists of almost 95% water and the remaining 5% consists of micro and macronutrients with maximum urea. Its dewatering could theoretically supply over 60% of the crew's water demand.

The concentrated urine will be diverted towards fertilizing food-based plants at space stations through a hydroponic process.