Researchers from RMIT have devised a method for manufacturing low-energy fired-clay bricks using the cigarette butts that are discarded in their trillions around the globe each year.
In addition to posing a serious threat to the physical health of smokers themselves, cigarettes are also a major source of harmful environmental pollution. The trillions of cigarette butts that are discarded around the globe each year have low levels of biodegradability, and can transmit toxic heavy metals such as arsenic, chromium, nickel or cadmium into the environment before they finally decompose.
According to Dr. Abbas Mohajerani, senior lecturer at RMIT's School of Engineering, this problem is set to worsen considerably over the next decade due to an expected surge in cigarette consumption.
"About 6 trillion cigarettes are produced every year, leading to 1.2 million tonnes of cigarette butt waste," said Mohajerani. "These figures are expected to increase by more than 50 per cent by 2025, mainly due to an increase in world population."
Mohajerani and his team believe they may have found the solution to this environmental dilemma, by developing a manufacturing process for fired-clay bricks that uses cigarette butts as an additive and reduces the cost of the final product.
The RMIT team claim that the incorporation of cigarette butts into bricks brings multiple benefits, whether they be economic, environmental or performance related.
While bricks comprised of 1 per cent cigarette butts for the most part retained the physical properties of regular bricks, they also proved to be lighter in weight and had enhanced insulation capabilities.
The manufacturing process itself brings environmental benefits, as any toxic pollutants contained by the cigarette butts are trapped within the brick, and prevented from leaching into the broader environment.
"Incorporating butts into bricks can effectively solve a global litter problem as recycled cigarette butts can be placed in bricks without any fear of leaching or contamination," said Mohajerani.
Another major benefit is that the use of cigarettes butts as a brick ingredient can reduce the amount of energy consumed during the manufacturing process by as much 58 per cent. Not only does this dramatically reduce the cost of brick production, it also has a positive environmental impact as it cuts down on carbon emissions created by energy usage.
"They are...cheaper to produce in terms of energy requirements, and as more butts are incorporated, the energy cost decreases further."
Mohajerani is confident that the widespread use of cigarette butts in brick production could produce more sustainable, better performing building material while also solving an endemic environmental problem.
"“In Australia alone, people smoke about 25 to 30 billion filtered cigarettes a year and, of these, about 7 billion are littered," said Mohajerani. "This research shows that if just 2.5 per cent of the world’s annual brick production incorporated 1 per cent cigarette butts, we could completely offset annual worldwide cigarette production.”