Waste Innovation : Australia: RMIT develops next level waste transformation technology

biosolids manure
© Maren Winter - stock.adobe.com

The Royal Melbourne Institute of Technology (RMIT) has developed a way to transform biosolids into recyclable biochar.

Biosolids are a mix of water and organic matter. They are nutrient rich by-products of the wastewater treatment process, in use as fertilisers for food crops but also as a means to improve forest productivity and revegetate areas disturbed by waste disposal, mining and construction activities. The nutrients within biosolids help stimulate plant growth as well as improve and maintain soil quality yet, despite their role as a beneficial resource, concerns have also been raised on account of the number of pollutants, heavy metals (ex. arsenic, mercury, cadmium, nickel and selenium) and pathogenic microorganisms contained within biosolids. As such, they may warrant a threat to environmental health over time.

Scientists at RMIT have now eliminated that risk through a unique pyrolysis (PYROCO) technology.

This technology makes use of high temperatures to eliminate both pathogens as well as micro-plastics, transforming said biosolids into biochar, a charcoal like by-product.

Currently, 30% of global biosolids are stockpiled or sent to landfill. The new approach to handling biosolids could help divert potentially toxic waste from landfill.

Steve McGhie, MP for Melton and Parliamentary Secretary for Health, said: “This collaboration will enable the water industry to find alternative markets for biosolids, reducing waste going to landfill and allowing 100% of products to be reused or recycled.”

“By creating a safe product with a steady supply stream, we’re also providing our farmers and the wider agriculture industry a product which is completely natural and can improve soil health and fertility.”

“This project is incredibly exciting for both industries and I can’t wait to see the outcome of the trial.”

The new pyrolysis technology is currently being trialled by South East Water, Intelligent Water Networks and Greater Western Water.

It makes use of a bespoke reactor patented by RMIT, which optimises heat and mass transfer while shrinking the technology itself to render it more mobile. The reactor also has potential applications in the biomass and plastic sector.

“Developing new ways to squeeze the full value from waste resources is critical in our transition to a circular economy, so we are thrilled this Australian-first technology has reached full trial stage,” Project Lead and Deputy Director of the ARC Training Centre for Transformation of Australia’s Biosolids Resource at RMIT Kalpit Shah, said.

“At the heart of RMIT research are our strong partnerships with industry, and we hope this collaborative trial will enable us to accelerate the translation of our innovation into new homegrown technologies that advance sustainability and make a real impact in water and agriculture.”

The next stage of the project will see a unit placed in a water recycling plant over a longer time span.