A team at RMIT University has demonstrated that clay-fired bricks incorporating biosolids could be a sustainable solution for the wastewater treatment and brickmaking industries.

Published this month in the journal Buildings, their research showed how making biosolid bricks only required about half the energy of conventional bricks.

As well as being cheaper to produce, the biosolid bricks also had a lower thermal conductivity, transferring less heat, to potentially give buildings a higher environmental performance.

Biosolids are a by-product of the wastewater treatment process that can be used as fertiliser, in land rehabilitation or as a construction material.

About 30 per cent of the world’s biosolids are stockpiled or sent to landfill, using up valuable land and potentially emitting greenhouse gases.

Associate Professor Abbas Mohajerani said the research sought to tackle two environmental issues, namely the stockpiling of biosolids and the excavation of soil required for brick production.

“More than three billion cubic metres of clay soil is dug up each year for the global brickmaking industry, to produce about 1.5 trillion bricks,” Prof Mohajerani, a civil engineer in RMIT’s School of Engineering, said.

“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.”