JCU researchers use charred ciggie butts to clean up wastewater

New research from James Cook University has produced results that might seem counterintuitive, showing that cigarette butts could offer a promising solution for tainted waterways.

The JCU team looked at char made out of cigarette butt waste, which was donated by the charity No More Butts. Their paper, published in the journal Chemical Engineering Science (linked), examined the results from treating the butts with pyrolysis at a range of temperatures between 400 and 700 degrees Celsius, and then using the resulting char to treat wastewater.

Pyrolysis involves heating with little or no oxygen.

One preparation was able to remove as much as 53 per cent of copper and 95 per cent of nickel from simulated wastewater in lab trials.

Engineering lecturer Dr Elsa Antunes said that activated carbon made of coal is one solution used to remove heavy metal from waterways, though a “circular economy” solution of char from cigarette butts is “much more sustainable” if used to treat pollution.

As an expert explained to @AuManufacturing last year, there are two dominant categories for making activated carbon: physical or chemical activation. One uses steam at about 1,000 degrees celsius to treat coal — releasing about 18 tonnes of CO2 per tonne of product created — and the other uses strong acids or bases.

“Our results were very interesting and could be applied at an industrial scale,” said Antunes in a statement from JCU on Friday.

“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.”

Antunes has previously worked with Townsville City Council on biosolid-derived char to remove phosphorous and nitrogen from waterways, and one of her Masters students is currently focussed on removing pharmaceuticals from wastewater.

Her team is now looking to continue its work on cigarette-based char to treat other contaminants.

Picture: credit JCU

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