

Water-Related News

One option for disposal of biosolids: recycling them to make sustainable bricks

How can you recycle the world’s stockpiles of treated sewage sludge and boost sustainability in the construction industry, all at the same time? Turn those biosolids into bricks.

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

Around 30% of the world’s biosolids are stockpiled or sent to landfill, using up valuable land and potentially emitting greenhouse gases, creating an environmental challenge.

Now a team at RMIT University in Melbourne, Australia, has demonstrated that fired-clay bricks incorporating biosolids could be a sustainable solution for both the wastewater treatment and brickmaking industries.

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

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

The EU produces over 9 million tonnes of biosolids a year, while the United States produces about 7.1 million tonnes. In Australia, 327,000 tonnes of biosolids are produced annually.

The study found there was a significant opportunity to create a new beneficial reuse market - bricks.