Cigarette butts, a scourge that leach heavy metals like arsenic, chromium, nickel and cadmium into soil and waterways, could soon find a new home locked inside bricks.
In Australia it is estimated that 25-30 billion filtered cigarettes are smoked a year, with around seven billion littered. These filters take around 18 months to biodegrade and, in the process, can wreak havoc on the environment.
Now researchers from RMIT University say they have the solution – adding the butts to the brick production process.
The team, led by Dr Abbas Mohajeran, found that adding one per cent cigarette butt content to bricks could cut production cost as well as help the environment, both through dealing with the problem waste stream and reducing the energy needed to fire the bricks.
“I have been dreaming for many years about finding sustainable and practical methods for solving the problem of cigarette butt pollution,” Dr Mohajeran said.
“About six trillion cigarettes are produced every year, leading to 1.2 million tonnes of cigarette butt waste. These figures are expected to increase by more than 50 per cent by 2025, mainly due to an increase in world population.”
Dr Mohajeran said that just 2.5 per cent of the world’s bricks using one per cent cigarette butt content would take care of the entire waste stream.
Additionally cigarette butt inclusion could reduce energy needed to fire bricks by up to 58 per cent.
The research also found that the bricks with cigarette butt content were lighter and had better insulative properties, which could lead to reduced heating and cooling costs.
“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,” Dr Mohajeran said.
“They are also cheaper to produce in terms of energy requirements, and as more butts are incorporated, the energy cost decreases further.”
However, as the proportion of cigarette butts increased, the compressive strength decreased, so bricks with a high proportion of butts might not be appropriate for some uses.
The article, A practical proposal for solving the world’s cigarette butt problem: Recycling in fired clay bricks, is published in the journal Waste Management.