- Article by Tili Bensley-Nettheim
RMIT University researchers have developed a plan to implement cigarette butt recycling into bricks at an industrial scale.
The study builds on RMIT research from 2016 that showed that fired-clay bricks with 1% recycled cigarette butt content are as strong as normal bricks and use less energy to produce.
The researchers found that if 2.5% of the bricks produced yearly around the globe were only 1% composed of cigarette butts, then energy consumption could decrease by 20 billion MJ, or the amount of power used by one million homes every year in Victoria.
The research team from RMIT’s University’s School of Engineering has now released a detailed plan for bringing the brickmaking and waste management industries together to actualise this research.
“Firing butts into bricks is a reliable and practical way to deal with this terrible environmental problem, while at the same time cutting brickmaking production costs,” says lead researcher Associate Professor Abbas Mohajerani.
“We need to do far more to stop cigarette butts from polluting our streets, rivers and oceans, and prevent them leaching harmful toxins into our environment.
“Our ultimate goal is a world free of cigarette butt pollution: our industry implementation plan outlines the practical steps needed to bring this vision to reality.”
The plan, published in a special issue of the journal Materials, details how cigarette butts can be collected and recycled on an industrial scale.
Different incorporation methods are outlined – using whole butts, pre-shredded butts, or a pre-mix where the butts have already been incorporated into other brickmaking materials.
By analysing the butts’ energy value, the team showed the incorporation of 1% cigarette butt content would reduce the energy required to fire bricks by 10%.
“It takes up to 30 hours to heat and fire bricks, so this is a significant financial saving,” Mohajerani says.
It can take many years for cigarette butts to break down, while heavy metals like arsenic, chromium, nickel and cadmium trapped in the filters leach into soil and waterways.
During firing, however, these metals and pollutants are trapped and immobilised in the bricks.
Bricks made with cigarette butts are also lighter and provide better insulation – meaning reduced household heating and cooling costs.
Mohajerani, who has spent over 15 years researching sustainable methods for cigarette butt recycling, has also developed technology for incorporating butts into asphalt concrete.
He said the technical solutions would need to be backed up by more stringent laws and harsher littering penalties.
“Local authorities would also need to provide more specialised bins for cigarette butts, to both prevent littering and enable smooth collection for the brickmaking process,” he said.
“My dream is a dedicated brickmaking recycling facility in every country, that can recycle butts and solve this pollution problem for good.”
Late 2020, a collaborative visualisation between RMIT Architecture students and the Drawing Architecture Studio has been awarded ArchDaily’s inaugural ‘Conceptual – Jury Winner’ prize. The large-scale panorama explores the “hidden narratives” of Melbourne’s built environment.
Lead photo: Davison Street designed by Archier. Photo by Tess Kelly.