By combining agricultural and industrial waste, bound by the Trametes versicolor fungus, scientists have developed a low-carbon, fire-resistant and termite-deterring building material, which costs less than synthetic plastics or engineered wood, and could reduce the amount of waste that ends up in the landfill.
Specifically, the new material is made from rice hulls (the indigestible part of rice) and glass fines (discarded, small or contaminated particles of glass), baked into lightweight bricks, which can be moulded into almost any shape due to their structure.
Given that producing such bricks is a low-energy and zero-carbon process, and considering the amount of waste generated globally in the processing of rice (a staple crop for more than half the world’s population), the potential savings and environmental benefits are nothing to sniff at.
Roughly 20% of the 480 million metric tonnes of rice consumed every year is comprised of hulls, and up to 600,000 tonnes of glass waste is generated annually in Australia (the home country of the researchers behind the discovery) alone.
Compared to synthetic construction materials such as polystyrene and particleboard (made from petroleum or natural gas), the new fungal bricks release less smoke and CO2, burn more slowly and emit less heat, making them ideal for use as fire-resistant insulation on construction sites due to potential gains in terms of occupational fire safety.
Furthermore, the new material is also highly unappetising to termites because of the silica contained in both rice and glass, which could prove highly beneficial to areas susceptible to termite infestations. The authors note that Australian home-owners alone spend more than A$1.5 billion a year on ridding their houses of the pesky insects.
“The findings of this study show that mycelium composites are a very economical alternative to highly flammable petroleum-derived and natural gas-derived synthetic polymers and engineering words for applications including insulation, furniture and paneling,” wrote the researchers in their paper out the journal Fire and Materials.