About 6 trillion cigarette butts are produced every year worldwide, leading to more than 1.2 million tonnes of cigarette butt waste. This is set to increase by more than 50 per cent by 2025, mainly due to an increase in world population.
Now an Australian research team is developing a way for cigarette butts can be turned into footpaths, bricks and other building materials - that have the added bonus of cooling our cities.
A team at RMIT University - led by Dr Abbas Mohajerani - has shown that an that asphalt/cigarette butts mixed material can both handle heavy traffic and also reduce thermal conductivity. This means the product could not only solve a huge waste problem but would also be useful in reducing the "urban heat island" effect common in cities.
Mohajerani, a senior lecturer in RMIT's School of Engineering, said he was keen to find solutions to mounting cigarette butt waste.
"I have been trying for many years to find sustainable and practical methods for solving the problem of cigarette butt pollution," Mohajerani said. "In this research, we encapsulated the cigarette butts with bitumen and paraffin wax to lock in the chemicals and prevent any leaching from the asphalt concrete. The encapsulated cigarettes butts were mixed with hot asphalt mix for making samples"
Mohajerani says the encapsulated cigarette butts developed in this research will be a new construction material which can be used in different applications and lightweight composite products.
"This research shows that you can create a new construction material while ridding the environment of a huge waste problem."
Cigarette filters are designed to trap hundreds of toxic chemicals and the only ways to control these chemicals are either by effective encapsulation for the production of new lightweight materials, or by the incorporation in fired clay bricks, according to Mohajerani.
Mohajerani became a world-renowned researcher in 2016 for his research in recycling cigarette butts in bricks. This project is the result of five years of research.