World-first: Bio-bricks from urine

Source - https://www.news.uct.ac.za/article/-2018-10-24-world-first-bio-bricks-from-urine

Somebody needs to drink more water.

But clearly nobody needs to come up with a more awesome idea than making fertilizer and 'cement' blocks from urine.

Some civil engineering grad students from Cape Town, South Africa have developed a process of taking urine - currently only male urine because “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?” - precipitating out a solid fertilizer, then using the liquid waste to produce bio-bricks  and a secondary fertilizer.

The initial precipitation at the fertilizer-producing urinal uses calcium hydroxide to precipitate out calcium phosphate, a solid fertilizer.

Source - https://www.sciencedirect.com/science/article/pii/S2213343718306043

After that, the remaining liquid heads to a secondary processing.

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.

And the strength of the material is simply dependent on time and concentration of urea.

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.”

The liquid waste from the bio-brick production, then, is further processed into a second fertilizer.

That's amazing, turning a waste product into three useful. As the article says, "[t]he overall scheme would effectively result in zero waste, with the urine completely converted into three useful products."

I'm guessing there are a lot of scientists who are pissed that they didn't come up with this idea themselves.

(I'm sorry...)