Humanist was used by university students in South Africa to produce eco-friendly bricks.
They combined urine with sand and bacteria in a process that causes the stones to solidify at room temperature.
Just as corals are made in the ocean, "said Dyllon Randall, her supervisor at the University of Cape Town, opposite the BBC.
Normal bricks need to be fired in high-temperature furnaces that produce large amounts of carbon dioxide.
" So hard as limestone "
The engineering students of the University of Cape Town (UCT) have harvested urine from male toilets.
After the first production of a solid fertilizer, the remaining liquid is then used in a biological process "to grow", which the university calls "bioblocks".
The process is called microbial carbonate precipitation.
The bacteria produce an enzyme that breaks down urea in the urine, forming calcium carbonate, which then turns the sand into rock-hard gray brick.
How many fissures break into a brick?
The strength and shape of the bio-blocks can be changed as needed.
"When we started this process last year, we achieved the same compressibility as a 40% limestone," Dr. Randall the BBC Newsday program.
"Only a few months later, we've doubled that strength Now, by changing the material we've put into the mold and allowing the bacteria to cement the particles for longer – at zero heat at room temperature."
Normal bricks are fired at temperatures around 1400C. according to the University of Cape Town.
But Dr. Randal admits that her process is much stinkier.
"Say you had a pet and it peed in the corner and you have that strong odor – that's ammonia released process produces ammonia as a by-product," he said, adding that ammonia in then Nitrogen-rich fertilizer is converted.
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But after about 48 hours, the bricks completely lose the ammonia odor – and they also have no health risks, he said.
The process we use in the first stage kills all harmful pathogens and bacteria because we are working at an extremely high pH, which has been shown to kill almost everything. "
According to UCT, the concept of using urea to grow bricks has been tested in the US Some years ago, synthetic urea was used in the US, which requires a lot of energy to produce.
The one by Dr. Randall and his student Suzanne Lambert and Vukheta Mukhari's manufactured bricks use for the first time real human urine, which offers opportunities to recycle garbage.
It takes between four and six days to grow – if you want a stronger stone, you can keep it longer.