Pee House? Cape Town Students Have Created Urine Biobricks

People in the 50s might have predicted flying cars in today’s time, but I bet they might have never predicted that the world will need alternative choices to keep the environment safe and habitable. And humanity has come to a possibility to live in a house made from urine bricks sooner or later.

“How the heck could something liquid be turned into a brick?” Well, if you’re very familiar with the gunpowder plot, you know that urine can be turned into something explosive. Well, apparently with some science and a natural process called microbial carbonate precipitation, you can turn it into biobricks. It’s similar to how seashells are formed.

Loose sand is colonised with bacteria that produce urease, an enzyme. It later breaks down the urea in urine and produces calcium carbonate through a complex chemical reaction, cementing the sand into any shape including a rectangular building brick.

Suzanne Lambert and Vukheta Mukhari, students who created this biobrick have worked so hard to lab test various brick shapes and tensile strengths so that it would be an innovative building material. Both students are supervised by Dr. Dyllon Randall and Professor Hans Beushausen from civil engineering department.

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

Urine biobricks perfected

Actually, the concept of using urea to grow bricks isn’t new. In fact, it was tested in the United States years ago but it used synthetic solutions. Lambert also built her work based on a research by Jules Henze who worked on this concept with Randall in 2017. And now, her brick uses real human urine with significant consequences for waste recycling and upcycling.

Useful byproducts

Just like any other thing, the production of this biobrick produces byproducts, nitrogen and potassium in this case. Both are important components of commercial fertilizers.

In addition, the bio-brick process produces as by-products nitrogen and potassium, which are important components of commercial fertilisers. According to Randall, urine has less than 1% of domestic wastewater (by volume) but it contains 80% nitrogen, 56% phosphorus, and 63% potassium.

97% phosphorus in the urine is can be converted into calcium phosphate, which is a key ingredient in fertilisers usually used by commercial farming. And with the fact that natural phosphate reserves are running dry, this biobricks would prove to be beneficial not just for making houses.

Waste free

Since the urine brick’s byproduct can be used, it means that there would be no production waste. Here’s how that happens; urine is firstly collected in fertiliser-producing urinals and used to make a solid fertiliser. Any liquid left is used for biobrick production.

“But in that process, we’re only after two components: carbonate ions and the calcium. What we do last is take the remaining liquid product from the bio-brick process and make a second fertiliser,” said Randall.

There are 3 products that the urine would produce, meaning there’s zero waste. Randall added that, “No-one’s looked at it in terms of that entire cycle and the potential to recover multiple valuable products. The next question is how to do that in an optimised way so that profit can be created from urine.”

Logistics such as urine collection and transport to a resource recovery are also something worth considering. Randall’s other student is currently investigating the transport logistics of urine collection and treatment and the result is very promising.

Other than that, urine biobricks won’t harm the environment since they’re made in moulds at room temperature. Regular bricks are kiln-fired at temperatures about 1 400°C and that produces a hecking lot of carbon dioxide.

Will the world be ready for this?

Both Lambert and Mukhari are optimistic about urine biobricks’ potential of innovation in the sustainability space. Lambert said, “This project has been a huge part of my life for the past year and a half, and I see so much potential for the process’s application in the real world. I can’t wait for when the world is ready for it.”

“Working on this project has been an eye-opening experience. Given the progress made in the research here at UCT, creating a truly sustainable construction material is now a possibility,” Mukhari added.

Randall stated that this innovation is changing how people view waste and its upcycling. “In this example you take something that is considered a waste and make multiple products from it. You can use the same process for any waste stream. It’s about rethinking things,” he said.

Source(s)

https://www.news.uct.ac.za/article/-2018-10-24-world-first-bio-bricks-from-urine
https://www.globalcitizen.org/en/content/bio-bricks-human-urine-cape-town/