Students behind surprising PFAS experiment can clean contaminated water using fabric softener

Normally, we associate new discoveries at the university with rigorous systematics and long scientific analyses aimed at providing new knowledge about the world over many years. However, the students' discovery is neither a new complicated theory nor a high-tech miracle, but rather the cheapest fabric softener you can find on the supermarket shelves.

It may turn out to reduce the costs of removing the dangerous PFAS substances from water.

"We were very surprised by our findings, but our data confirms the results, and we have subsequently studied the chemical composition of fabric softener to gain a better understanding of why it works," says Olaf Vilhelm Sckerl, who recently graduated as a Bachelor of Engineering in biotechnology from Aarhus University.

Highly toxic water

Olaf Vilhelm Sckerl and his fellow student, Jonas Skov, discovered the effects of fabric softener in a laboratory at Aarhus University during their joint Bachelor's project at the Department of Chemical Engineering and Biotechnology.

In their experiments, they saw that they could remove PFAS from contaminated water much more efficiently by adding just a tiny amount of fabric softener.

"We saw a significant improvement. The fabric softener contains active substances that can replace some of the costly purification chemicals used by industry today. We have a clear expectation that this can be an effective and cost-reducing supplement," says Jonas Skov.

The water used by the two engineering students in their experiment comes from one of Denmark's more than 500 buried landfills with waste containing environmentally problematic waste.

Wastewater below these landfills is collected so it can be sent to the municipal treatment plant instead of leaching into the groundwater.

"We tested the water samples we received in our project for the 22 most common PFAS compounds. We conducted several experiments, all of which showed the same result: Fabric softener appears to have a significant reducing effect on PFAS values," says Olaf Vilhelm Sckerl.

The PFAS content in the samples was subsequently analysed in a professional laboratory, which, among other things, also conducts studies for waterworks.

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The students received samples of wastewater from an underground landfill and tested the effect of fabric softener on the 22 most common PFAS compounds. (Photo: Jens Hartmann)

Global group takes discovery further

In their project, the two engineering students collaborated with the Danish branch of the company ECT2, which is a world leader in landfill remediation technology. The company is very interested in the results.

"We called our contact person at the company and said: 'We know this might sound a bit strange, but would you mind if we included fabric softener in our protocol?' They were very supportive," says Jonas Skov.

ECT2 has now decided to proceed with more tests of the active substance in fabric softener that seems to improve the treatment processes.

"The project results are extremely interesting, and we'll initiate a number of additional experiments. Among other things, we need to ascertain the most effective doses and find out which PFAS compounds the fabric softener works on," says Tore Svendsen, General Manager of ECT2.

Today, a flocculating agent is used to treat environmentally problematic wastewater from underground landfills. This causes unwanted microscopic particles in the water to clump together and subsequently separate.

Fabric softener seems to encourage this accumulation of sediment in the contaminated water and thereby improve the treatment. However, it does not solve all the problems with PFAS.

"Landfills are very different, and the mixture of PFAS compounds in wastewater from landfills can vary enormously. We still don't know how the concentration and composition of PFAS compounds impacts the effects of fabric softener, nor do we know how we can remove PFAS from nature completely. But we hope that our discovery can contribute to streamlining treatment processes and make them cheaper and more accessible all over the world," says Jonas Skov.