I was taken aback (sort of) by reading about a new technique for producing bricks . . . using human urine.
The world’s first ‘bio-brick’ made from human urine was unveiled by University of Cape Town (UCT) civil engineering masters student Suzanne Lambert on Wednesday.
. . .
Dr Dyllon Randall, Lambert’s supervisor and senior lecturer in water quality at UCT, explained that the “bio brick” is created through a natural process called microbial carbonate precipitation.
“It’s not unlike the way seashells are formed,” Randall said.
Parts of the urine are combined with loose sand and a bacteria to produce an enzyme called urease which breaks down the urine to produce calcium carbonate through a complex chemical reaction.
The calcium carbonate turns the sand into “cement”. The bricks are made in moulds at room temperature – better for the environment, as 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.
There’s more at the link.
I daresay this process might have all sorts of useful applications in areas where bricks are hard to come by and/or make . . . but I can’t help feeling a bit queasy about the process. How are you going to go about collecting the urine? Shared urinals draining into a barrel? If you can’t flush them, that’s going to get a bit aromatic after a while. The article also points out that men might have an easier time “donating” urine than women, particularly where tribal taboos predominate (which, in Africa, is a large part of the continent). And what about “number two”? It’s going to be hard, if not impossible, to separate “number one” from the solids involved. Can animal urine also be used? If so, how to collect it?
Still, those are just details. If the new process works, and it’s cheaper and easier than current technology, there’s sure to be interest in it. I just hope the odor of urine doesn’t carry over to the bricks – or the houses built with them!