Materials

Scientists build bricks with human urine

This technology leading to bricks made with human urine has the potential to produce more than just environmentally friendly building materials
This technology leading to bricks made with human urine has the potential to produce more than just environmentally friendly building materials
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 Dr Dyllon Randall, left, supervised the research leading to the bricks made with human urine
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 Dr Dyllon Randall, left, supervised the research leading to the bricks made with human urine
This technology leading to bricks made with human urine has the potential to produce more than just environmentally friendly building materials
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This technology leading to bricks made with human urine has the potential to produce more than just environmentally friendly building materials
The ways modern science has harnessed the waste products of the human body for good may surprise
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The ways modern science has harnessed the waste products of the human body for good may surprise
Researchers say they can produce bricks of various strengths using human urine
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Researchers say they can produce bricks of various strengths using human urine
The urine biological bricks are made in molds at room temperature
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The urine biological bricks are made in molds at room temperature
A team from the University of Cape Town have developed the world’s first biological brick made with human urine
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A team from the University of Cape Town have developed the world’s first biological brick made with human urine

The ways modern science has harnessed the waste products of the human body for good may surprise, with researchers recently using urine to power mobile phones, hydrogen vehicles and even form biological concrete. Now a team from the University of Cape Town has developed what it says is the world's first biological brick made with human urine, with the strength able to be tweaked to serve a range of needs.

The technology is based on a similar natural process that results in seashells, called microbial carbonate precipitation. Granules of loose sand are colonized with bacteria that produce an enzyme called urease. When confronted with urine, the urease breaks down a compound within it called urea, and it is this chemical reaction that produces calcium carbonate to form the structure.

Over a number of months, engineers at the University of Cape Town have been experimenting with this process to produce materials of differing shapes and tensile strengths. The sand can be coaxed into solid columns and cylinders, but it was the form of a rectangular brick that had the team particularly enthused about their breakthrough.

 Dr Dyllon Randall, left, supervised the research leading to the bricks made with human urine
 Dr Dyllon Randall, left, supervised the research leading to the bricks made with human urine

By testing these different recipes, the teams says it can produce bricks of various strengths, tailor-made to suit a customer's needs. It has significant environmental benefits too because they form in molds at room temperature, whereas regular brick-making involves bringing kilns to temperatures of around 1,400° C (2,550° F), which produces carbon dioxide as a by-product.

"If a client wanted a brick stronger than a 40 percent limestone brick, you would allow the bacteria to make the solid stronger by 'growing' it for longer," says Dr Dyllon Randall, who supervised the research. "The longer you allow the little bacteria to make the cement, the stronger the product is going to be. We can optimize that process."

This technology has the potential to produce more than just environmentally friendly bricks. Describing urine as "liquid gold," the team points to the high amounts of nitrogen, phosphorous and potassium within it that can be captured and used as ingredients for commercial fertilizer, which would essentially equate to a manufacturing process that produces zero waste.

"In this example you take something that is considered a waste and make multiple products from it," says Randall. "You can use the same process for any waste stream. It's about rethinking things."

Source: University of Cape Town

6 comments
Nik
Stones are quicker and cheaper and a lot easier to obtain. In Victorian times urine from London's public lavatories was collected and shipped north for the textile industry, until the required product was synthesised by the chemical industry, then the urine was used to pollute the Thames.
Username
How many gallons of pee is needed to make one brick?
toyhouse
They don't mention what kind of bacteria is used. Not having to fire the brick is interesting and no doubt, creating hybrid mixtures as they do with concrete could yield interesting results. On a side note; adobe bricks were made with manure/hay or both, left out to dry in the sun. They can't carry the same loads as fired bricks however. Structures were usually limited to two stories else walls had to be built-out and tapered. New construction in many parts of America are no longer allowed due to earthquake and thermal codes. Wonder how the urine bricks stack-up, (pardoning the pun), in those areas.
Leonard Foster Jr
If they are not fired do they Smell after being wet ???
amazed W1
The process presumably mimics the formation of kidney and bladder stones, and these can be really and uncomfortably hard and large.
Chizzy
It's not a new idea at all, just smaller in scope. Brick instead of product. https://newatlas.com/dupe-sand-urine-bacteria-concrete-machine/30804/