Global waste management facilities stockpile around 30 percent of treated sewage sludge. This solid waste matter is the byproduct of the wastewater treatment process and is either sent to landfills or stored in secure bio-hazardous facilities. However, this biosolid waste has value; scientists have started using it to create sustainable bricks for the construction industry.
The world uses billions of cubic metres of clay and soil per year to manufacture bricks. Using biosolid treated sewage in this process could make the brickmaking industry more sustainable and offer a new market for wastewater treatment facilities to sell their byproduct.
Research into using solid sewage waste for brickmaking
Researchers at RMIT University in Melbourne, Australia, have been adding biosolid waste to clay-fired bricks in order to assess their performance and capabilities as building materials. Their research has shown that making bricks from solid sewage waste only uses half the energy to produce than that of conventional clay bricks.
These biosolid bricks are also cheaper to manufacture and have a lower temperature conductivity. This means that they are better insulators and can give buildings an improved environmental performance. Building constructed with biosolid bricks will have less reliance on air conditioning and heating units for temperature regulation.
Millions of tonnes of solid sewage waste are stockpiled each year. The researchers report that using just 15 percent of biosolid content in clay bricks could use up this stockpiled waste. It’s a real opportunity to harness the value of solid sewage waste and add additional income to wastewater treatment facilities.
Researchers tackling environmental issues
The lead researcher, associate professor Abbas Mohajerani, says that the purpose of their work is to tackle two key environmental issues – the stockpiling of biosolid waste and the large excavation volumes of clay for brickmaking.
“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,” states 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 adds.
The team at RMIT University have studied various properties of the sewage bricks. They have also adjusted the proportions of biosolid waste to clay, from 10 to 25 percent. The biosolid bricks passed a range of compressive strength tests and safety standards. However, they do admit that there is still further testing that needs to be done before the bricks can go into full-scale production.
Averda is a leading waste management provider with over 50 years of experience across three continents. Through growth, transformation and engagement, we strive to find new ways of managing waste while protecting the community and environment.
By pairing international expertise with local insights, we have secured our position as one of South Africa’s most respected providers of waste management and industrial cleaning services. We also operate in the recycling, pipe inspection, CCTV, infrastructure inspection, hydro-demolition, high-pressure water jetting and catalyst handling industries.
Follow us on Facebook, Twitter and LinkedIn for the best tips on recycling and the latest industry news. See our Instagram and YouTube channels for more insights into environmental affairs and our work with local communities.