Visits to loo more than a wee thing

LIQUID gold has been discovered at the University of Cape Town.

It is urine‚ which engineering students have turned into fertiliser and bricks.

UCT says urine from its urinals has the potential to produce six tons of fertiliser a year – twice the amount it uses on its sports fields.

“Chemically speaking‚ urine is liquid gold,” civil engineering lecturer Dyllon Randall said.

“It makes up less than 1% of domestic wastewater, but contains 80% of the nitrogen‚ 56% of the phosphorus and 63% of the potassium of this wastewater.

“We pee away these valuable nutrients every day.”

After spending two years in Switzerland working on a “reinvent the toilet” challenge funded by the Bill and Melinda Gates Foundation‚ Randall challenged four civil engineering doctoral students to continue his work‚ which was aimed at making toilets self-sufficient.

Craig Flanagan built a urinal containing calcium hydroxide‚ which reacted with urine to produce calcium phosphate.

Phosphate is a key ingredient in fertilisers‚ but natural deposits of phosphate are expected to expire within the next 50 years.

Student Suzanne Lambert took Flanagan’s leftover urine and put it into sand that had been colonised with an enzyme that produces calcium carbonate.

Randall said this cemented the sand into any shape – such as a brick.

By-products of the biobrick process are nitrogen and potassium‚ which are also used in fertilisers.

Bilaal Kowdur harvested 110 litres of urine from 10 makeshift urinals at a UCT residence and used it to make nearly 2kg of fertiliser.

Tinashe Chipako researched the feasibility of installing waterless urinals on campus and found that UCT used the equivalent of about seven Olympic-sized swimming pools of water annually just to flush urinals.

Flanagan won a R30 000 Greenovate Award for environmental achievement.