9 Aug 2017

Could cigarette butts have a second life as pavement?

From Jesse Mulligan, 1–4pm, 1:23 pm on 9 August 2017
Trillions of cigarettes are produced worldwide each year, with most being discarded, causing environmental problems.

Trillions of cigarettes are produced worldwide each year, with most being discarded, causing environmental problems. Photo: Pixabay

Every year, 6 trillion – that’s a 6 and 12 zeros – cigarette butts are produced around the planet and most are discarded.

Cigarette filters are designed and manufactured to lock in the thousands of chemicals found in cigarette smoke of which at least 60 are carcinogenic.

But now an engineer in Australia has come up with a solution for the butts that could reduce harm to the environment and add value to our roads and highways.

Mix the butts with asphalt, and, hey presto, you've got a brand new construction material.

Dr Abbas Mohajerani from RMIT's School of Engineering talks with Jesse Mulligan about the idea.

Currently, only a small percentage of cigarette butts are collected (in cities) and sent to landfill.

Mohajerani envisages a system where many more would be collected and then sent instead to manufacturing plants.

11 years ago his team started recycling butts burning them into fired clay bricks.

The energy required to fire bricks is huge, Mohajerani says.

“Just adding 1 percent cigarette butts can save 10 percent of the energy required.”

Another idea is to recycle ‘encapsulated’ butts which wouldn’t get opened up and the chemicals they contain exposed to the environment.

They can be added in encapsulated form to hot bitumen and hot paraffin wax in order to produce a new aggregate.

Cigarette-butt infused asphalt – which is lighter, more porous and retains less heat than straight asphalt – could help combat the problem of asphalt pavements heating up in summer and making hot cities even hotter.

For the recycling / reuse of cigarette butts into materials to take off, city councils would have to step up and play a crucial role engaging and communicating with manufacturers, waste management people and researchers, Mohajerani says.

Get the new RNZ app

for easy access to all your favourite programmes

Subscribe to Jesse Mulligan, 1–4pm

Podcast (MP3) Oggcast (Vorbis)