Could houses and other buildings of the future be made from our poo? Yes, according to an Australian university, which claims the innovation could revolutionise the brick manufacturing industry.
A joint research project funded by RMIT University, Melbourne Water and the Australian Government Research Training Program explored whether using biosolids as a construction method was a feasible idea.
Their research, published in this month’s issue of Building journal, found that biosolids — the by-product of wastewater treatment — can indeed be treated and compressed to make the sturdy construction material.
An estimated 30 per cent of the world’s biosolids are sent to landfill or stockpiled, to be used as a fertiliser or in land rehabilitation.
And biosolids are in no short supply. Some 327,000 tonnes of it are produced in Australia each year. In the US, around 7.1 million tonnes is generated, while the EU produced more than 9 million tonnes.
According to the team at RMIT, bricks made from biosolids deliver a number of benefits: they reduce the amount of the substance winding up in landfill, reduce the environmental impact associated with digging up clay and are cheaper to produce than traditional bricks.
Additionally, the researchers believe biosolid bricks may improve the energy efficiency of buildings, given that they have a lower thermal conductivity. Plus they use less energy to make — bricks comprising 25 per cent biosolids were found to use up to 48.6 per cent less energy during the brick firing process.
“More than 3 billion cubic metres of clay soil is dug up each year for the global brickmaking industry, to produce about 1.5 trillion bricks,” said the project’s lead investigator, Associate Professor Abbas Mohajerani.
“Using biosolids in bricks could be the solution to these big environmental challenges. It’s a practical and sustainable proposal for recycling the biosolids currently stockpiled or going to landfill around the globe.”
He suggested that some 5 million tonnes of biosolids from Australia, New Zealand, the US, Canada and the EU combined end up in landfill each year, but that this entire amount could avoid being thrown out if just 15 per cent of the bricks produced by these countries contained a minimum of 15 per cent biosolids.
Asked about the next steps of its research, and whether the university has any ideas about when such bricks could be made commercially available, a spokesperson said that research is still in its early stages but that “RMIT is keen to collaborate with relevant industries to investigate opportunities for commercialising this product”.
Adam Zuchetti is the editor of My Business, and has steered the publication’s editorial direction since early 2016.
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