October 26, 2018

A look at the world’s first bio-bricks made from urine

Got news? Next submission deadline is Friday at 5:00 p.m.

The world’s first bio-brick grown from human urine has been unveiled by University of Cape Town (UCT) master’s student in civil engineering Suzanne Lambert, signalling an innovative paradigm shift in waste recovery.

The bio-bricks are created through a natural process called microbial carbonate precipitation. It’s not unlike the way seashells are formed, said Lambert’s supervisor Dr Dyllon Randall, a senior lecturer in water quality engineering.

In this case, loose sand is colonised with bacteria that produce urease. An enzyme, the urease breaks down the urea in urine while producing calcium carbonate through a complex chemical reaction. This cements the sand into any shape, whether it’s a solid column, or now, for the first time, a rectangular building brick.

For the past few months Lambert and civil engineering honours student Vukheta Mukhari have been hard at work in the laboratory testing various bio-brick shapes and tensile strengths to produce an innovative building material. Mukhari is being co-supervised by Professor Hans Beushausen, also from the civil engineering department. Beushausen is helping to test the products.

The development is also good news for the environment and global warming as bio-bricks are made in moulds at room temperature. Regular bricks are kiln-fired at temperatures around 1 400°C and produce vast quantities of carbon dioxide.

The strength of the bio-bricks would depend on client needs.

“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,” said Randall.

“The longer you allow the little bacteria to make the cement, the stronger the product is going to be. We can optimise that process.”

Keep reading on the University of Cape Town website

Watch our video and learn more about the benefits of joining Construction Links Network – the peer-to-peer network sharing platform for the construction, building and design community.

Tweet Share LinkedIn

Submit YOUR Content ❯