World’s First Urine Bio-Brick Made From Male ‘Liquid Gold’

South Africa's University of Cape Town has unveiled the world's first bio-brick grown from human urine.

Urinals against a brick wall
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South Africa's University of Cape Town has unveiled the world's first bio-brick grown from human urine.

The University of Cape Town unveiled the world’s first bio-brick grown from human urine on Wednesday, October 24. According to the University of Cape Town master’s student in civil engineering Suzanne Lambert, a natural process called microbial carbonate precipitation was used to create this sustainable product that may change the masonry landscape. Lambert and a civil engineering honors student, Vukheta Mukhari, tested tensile strengths and bio-brick shapes in order to produce this eco-friendly brick.

Dr. Dyllon Randall, Lambert’s supervisor, said that the bricks were formed in a manner similar to the way seashells are formed. He said that loose sand was combined with bacteria that produce an enzyme called urease. Urease is then responsible for breaking down the urine so that it formed calcium carbonate. In turn, calcium carbonate bonds with the loose sand creating “cement.” This is the first time that a rectangular building brick has been molded from the resulting cement which formed.

The bio-bricks will have a positive impact on the environment and sustainability front. The bio-bricks are essentially left to grow and develop in molds at room temperature, whereas regular bricks are fired at temperatures of approximately 2,000 degrees F.

Another advantage of the bio-bricks versus kiln-fired bricks is that when conventionally made bricks are made, copious amounts of carbon dioxide is produced. Conversely, when bio-bricks are made, the by-products are nitrogen and potassium which could be used to make fertilizers. Consequently, there is zero waste.

Randall explained that the bricks’ strength could be grown according to the clients’ needs. The unique way in which the bricks are produced allows for a degree in tensile variance.

“If a client wanted a brick stronger than a 40% limestone brick, you would allow the bacteria to make the solid stronger by ‘growing’ it for longer.”

Randall also called urine “liquid gold” because of its high concentration of nitrogen, phosphorous, and potassium. Since the world’s natural phosphate reserves are rapidly depleting, urine’s inherent composition should be noted. Phosphorous can be converted into calcium carbonate, which is used internationally in commercial farming fertilizers.

The concept for the bio-bricks was first explored in the United States in 2010 where a synthetic solution was used. In 2017, Randall and Jules Henze built on this foundation before Lambert used real urine for the first time. When asked where she collected her urine for her bio-bricks, Lambert provided an eye-opening answer.

“At the moment we’re only dealing with urine collection from male urinals because that’s socially accepted. But what about the other half of the population?”