A team of RMIT University researchers has successfully demonstrated a more energy-efficient way to manufacture fired-clay bricks using cigarette butts. In doing so, the research team led by Dr Abbas Mohajerani has also found a solution for a significant global littering problem.
Cigarette butts from trillions of cigarettes produced every year worldwide result in millions of tonnes of toxic waste being dumped into the environment. The butts, due to their poor biodegradability, take years to break down while heavy metals such as arsenic, chromium, nickel and cadmium trapped in the filters leach into the soil and waterways.
The RMIT team has found that bricks with as little as 1 per cent cigarette butt content can cut brick production costs and save the environment by reducing the amount of waste generated.
According to Mohajerani, a senior lecturer in RMIT’s School of Engineering, about 6 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. In Australia alone, people smoke about 25 to 30 billion filtered cigarettes a year with about 7 billion ending up as waste.
Seeking to find sustainable and practical methods for solving the problem of cigarette butt pollution, the research team established that even if 2.5 per cent of the world’s annual brick production incorporated 1 per cent cigarette butts, the annual worldwide cigarette production could be completely offset. The use of these butts would also reduce the energy needed to fire bricks by up to 58 per cent.
There are other advantages too. Fired-clay bricks incorporating cigarette butts not only maintained properties very similar to those of normal bricks, but were also lighter with better insulation properties, helping reduce household heating and cooling costs. Additionally, the toxic elements in cigarette butts are trapped and immobilised in the bricks, reducing problems caused by leaching.
Mohajerani added that 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. Energy costs correspondingly decrease as more butts are incorporated into the bricks.
Image: Dr Abbas Mohajerani has shown that bricks with 1 per cent cigarette butt content like these pictured here can help the environment.