You read it right. Scientists at RMIT University have found a new way to recycle sewage waste and boost sustainability in the construction industry all at the same time. The magic ingredient? Biosolids.
The researchers suggest that by incorporating biosolids into fireclay bricks, we can address not one, but three environmental issues – sewage treatment waste, excessive clay extraction and carbon footprint of brick manufacturing.
Biosolid bricks are cheap, require half the firing energy to produce and transfer less heat than conventional bricks giving buildings higher environmental performance.
Every year around 5 million tonnes of the biosolids are produced in Australia, New Zealand, the EU, the US and Canada. The treated waste is either piled up in storage facilities, sent to landfill or discharged to the ocean.
By introducing a minimum of 15% biosolid content in only 15% of all bricks produced, waste associated with sewage treatment can be eliminated completely.
Lead investigator Associate Professor Abbas Mohajerani pointed out the importance of the research:
“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. Using biosolids in bricks could be the solution to these big environmental challenges.”
Are biosolids safe?
About 70% of Australian biosolids are currently used as an effective fertiliser in the agricultural sector. Waste materials go through a rigorous treatment process. The Environmental Protection Authority has strict rules and guidelines for the use of biosolids and they are generally deemed safe. However, further testing is required before biosolids can hit the shelves.