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Students from South Africa made bricks from human urine

Bio-brick made from human urine with the addition of sand and some bacteria

The bio-brick was made by Cape Town students who collected urine from specially designed male urinals in the engineering building of the university and mixed it with sand and bacteria. They are made in molds at room temperature. Nitrogen and potassium, which are important for commercial fertilizers, are created as by-products during the process. The process known as microbial carbonate precipitation allows the building material to be created at room temperature.

In this example, you take something that is considered waste and produce several products from it. You can use the same process for any waste stream. It’s about rethinking things. If a client wants a brick that is stronger than limestone brick (forty percent), we would allow the bacteria to make a solid body stronger by “growing” it longer.

Dillon Randall
Senior Lecturer at the University of Cape Town

Despite recent experiments, the pioneering work of Cape Town students is being questioned, since in 2010 there were already attempts to create bricks from human urine. Also claimed is the claimed strength of the organic material. On the Moss scale, limestone has 3 points, and brick (depending on the composition) from 5 to 7 points

The loose sand in which the bacteria producing urease were placed is mixed with urine. Urease destroys urea in the urine, producing calcium carbonate, which cements the sand into a mold. While ordinary bricks are fired in a furnace at a temperature of 1400C and produce large amounts of carbon dioxide, bioc bricks do not require as much heat. The strength of a bio-brick can also be adjusted to the needs of the client, as the bacteria inside the brick regulate strength.

Randall described the urine as “liquid gold.” By volume, urine is less than 1% of household wastewater, but it contains 80% nitrogen, 56% phosphorus and 63% potassium contained in wastewater. The vast majority of the phosphorus present in urine can be converted to calcium phosphate, the most important ingredient of fertilizers.

This attempt is not the first to use urine in everyday life. Previously, scientists have already tried to use urine as a cheap source of energy, as well as in gardening

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