There is no doubt that cigarette butts are a blight on our environment, especially our waterways. But a team at James Cook University (JCU) are giving this humble bit of trash a new lease on life where they can actually lend a helping hand.
It seems that environmentally hazardous cigarette butts may ironically hold the answer to cleansing Australia’s waterways of major metal contaminants.
JCU Lecturer in Mechanical Engineering Dr Elsa Antunes and her team found that char created from thermally decomposing cigarette butts in an oxygen-free chamber removed some about 53 per cent of copper and 95 per cent of nickel during lab trials with simulated wastewater.
The butts were provided by anti-cigarette waste charity No More Butts.
“Heavy metals are still a problem in our waterways and the consequences of heavy metals for humans and other living organisms are also very high,” Dr Antunes said.
“At the moment, you can use activated carbon, which is produced from coal, to remove heavy metal from our waterways, which is not an environmentally friendly product.
“But if we can create this circular economy where we can collect these cigarette butts, transform them into char and then use that to mitigate pollution, then that is much more sustainable.”
Dr Antunes said while a range of other materials such as wood and biosolids have previously been converted into biochar to target different contaminants in wastewater and they were also very effective in removing heavy metals.
“Our results were very interesting and could be applied at an industrial scale,” she said.
“The chemical composition of the char will have an impact in the removal of the contaminants, so when we are making char, we think about what contaminant we want to remove and then select the raw material best suited to that.
“But what we’ve also found is we are able to control the production conditions to obtain different porosities, or surface area, of the char, which can be used to target different contaminants.”
Dr Antunes’ work with char has already shown promising results, having previously worked with Townsville City Council to remove phosphorous and nitrogen from waterways using char made from biosolids.
She said her team are now keen to test the cigarette-based char on different contaminants in order to gauge its effectiveness compared to other forms of char.
“One of my Masters students is working on removing pharmaceuticals from wastewater, so this could be another potential use,” she said.
No More Butts CEO Shannon Mead said landfill re-direction to enable scaled recycling solutions, using a variety of innovative methods, will create employment opportunities and the ability to manufacture new materials for various industries, such as construction and packaging.
“Cigarette butts are the most littered item in Australia, with an estimated 8.9 billion being littered each year. Containing toxic chemicals and heavy metals, they poison the soil and water,” Mr Mead said.
By the numbers:
- Up to 4.5 trillion butts are littered globally each year.
- In Australia, a WWF report estimates that up to 8.9 billion cigarette butts are littered annually.
- Clean Up Australia reports that cigarette butts are 14% of all recorded litter in Australia.
- Research shows it can take up to 15 years for cigarette butts to break down in sea water.
- In addition to causing hundreds of fires each year, up to 7,000 chemicals from butts leach into the environment.
- Based on Australian estimates of litter and waste, an ash tray the size of Margaret Court Arena would be full of cigarette butts in less than 2 years.
