`Biosolids make bricks more sustainable`

Treated sewage sludge – biosolids – can easily be recycled by processing them into brick. This not only solves a waste problem (biosolids are still often landfilled) but can also make the construction industry more sustainable. That’s what scientists at RMIT University in Melbourne say. They investigated the possibilities of  firing biosolids with clay into full-fledged bricks. The research was published in January in the journal Buildings under the title ‘A Proposal for Recycling the World’s Unused Stockpiles of Treated Wastewater Sludge (Biosolids) in Fired-Clay Bricks’.

Biosolids are a by-product of the wastewater treatment process. It can be used as a fertilizer, in land restoration or as a construction material. Worldwide, about 30 percent of these biosolids are stored or landfilled, with the necessary environmental impact. A team from RMIT University in Melbourne, Australia, says it has shown that baked brick with biosolids can be a sustainable solution for both the wastewater treatment industry and the brick industry. In addition, the research shows that the production of biosolids bricks requires only about half the energy compared to the production of conventional bricks.

The biosolids bricks were not only cheaper to make, but also had lower thermal conductivity. Less heat transfer makes buildings more environmentally friendly.

More in Innovative Materials 2019 number 1