Africa Water, Sanitation & Hygiene Nov - Dec Vol. 9 No.6 | Page 15

Research

Exploit urinals for cheap fertilizer, says Indian inventor
market his innovation, about 4,000 units have been
installed in India.
His prefabricated Waterless Public Urinal Kiosks
store urine in tanks and use a patented cartridge
to stop the smelly gases escaping. This eliminates
the need for fresh water to flush away the urine, he
explains. According to the company’s website, the
cartridge uses a ball valve to trap the gasses, whereas
other models use membranes or liquid sealants that
gradually degrade and need replacing.
For “high-volume” urinals in public places, each
urinal can save 155,000 litres of fresh water a year,
Image credit: Flickr/waterdotorg he adds.
But there has been little interest in using the design’s
Recycling urine collected at public toilets is a cheap and
potential to harvest urine, he says, with nearly all
simple way to produce fertilizer, according to the developer of the urine being disposed of through traditional sewage
of a waterless urinal.
systems.
Human urine contains three nutrients — phosphorus, Chariar puts this partly down to politicians thinking that
nitrogen and potassium — that are essential for plant the cost of transporting urine would be prohibitive. Yet he
growth, says Vijayaraghavan Chariar, a researcher at the notes that simply adding magnesium chloride to urine and
Indian Institute of Technology Delhi.
adjusting its acidity will lead to a phosphate mineral called
Each person p ɽ