A new research study has developed a versatile, scalable platform using functionalised iron oxide nanoparticles to magnetically extract PFAS forever chemicals and fluorine-containing microplastics from complex contaminated water samples.
Scientists have developed magnetic iron oxide nanoparticles that could provide a new way to remove PFAS ‘forever chemicals’ and fluorine-containing microplastics from contaminated water.
Johannes Voß and Linda Rockmann, members of Professor Halik’s research team at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), developed iron oxide nanoparticles with specially modified surfaces designed to bind to different PFAS compounds. The approach could allow pollutants to be captured and then removed from water using a magnet.
Rather than targeting individual PFAS compounds, the researchers wanted to develop a flexible system that could work across the broad and chemically diverse PFAS family. By altering the surface of the nanoparticles, the team can tailor their interactions with different pollutants.
Extending the technology to microplastics
The research expands the potential application of magnetic water purification beyond molecular PFAS. The scientists report that they have demonstrated, for the first time, that the same underlying principle can be used to remove fluorine-containing microplastics.
These particles can be released through the abrasion of functional clothing during washing and can also occur in some cosmetics.
The nanoparticles work by binding pollutants to their specially engineered surfaces. Once the contaminants have attached to the particles, a magnet can separate the pollutant-laden nanoparticles from the water.
The researchers tested different surface modifications and found that their properties varied according to the functionalisation used. One material reliably removed a broad range of PFAS from water containing complex mixtures of other substances and organisms, including laundry wastewater and river water.
Our technology bridges the gap from molecular pollutants to microscopic particles and underscores the potential of functionalised iron oxide nanoparticles as a versatile and sustainable platform for water treatment, even for samples contaminated with a complex mixture of pollutants.”
Dr Marcus Halik, Professor for Polymer Materials, FAU
Testing contaminated water
Researchers examined a wide selection of PFAS, including neutral and charged molecular compounds as well as perfluorinated microplastics and nanoplastics known as fluoropolymers.
They tested the nanoparticles in several types of water, including uncontaminated water, river water, drinking well water, soil leachate and washing machine wastewater. The pollutants could be removed both individually and when present as mixtures.
Some of the iron oxide nanoparticles developed by the team can also be regenerated and reused following magnetic separation. The researchers say the materials are scalable and non-toxic, adding to their potential for use in water treatment.
Real-world trials show promise
The scientists also tested the technology outside controlled laboratory conditions, using samples from a contaminated drinking water source, river water, wash water from soil remediation and water used to wash outdoor textiles.
When using these samples, the scientists reduced PFAS concentrations from a contaminated drinking water source by 87 percent, which meant it dropped below the new German limit of 100 nanograms per liter.
The scientists also successfully removed fluorine-containing microplastics using magnetic separation, demonstrating the technology’s potential to tackle both molecular pollutants and microscopic particles.
Together, the findings suggest that functionalised iron oxide nanoparticles could eventually provide a recyclable and scalable approach to treating water contaminated with complex mixtures of PFAS and fluorine-containing plastics.
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