Scientists have developed a new technology that uses tiny magnetic particles to remove harmful “forever chemicals” from contaminated water.
The approach not only captures a wide variety of these persistent pollutants but can also remove fluorine-containing microplastics, offering a promising new tool for cleaning drinking water and protecting the environment.
The research was carried out by a team from Friedrich-Alexander University Erlangen-Nürnberg (FAU), University Hospital Erlangen and the Bavarian Health and Food Safety Authority.
Their findings were published in the journal Materials Today.
Forever chemicals, also known as PFAS, are a large group of human-made compounds used in products such as non-stick cookware, waterproof clothing, food packaging, firefighting foams and many industrial materials.
They are valued because they resist heat, water and oil. However, these same properties also make them extremely difficult to break down in nature.
PFAS can remain in soil, rivers and groundwater for many years, earning them the nickname “forever chemicals.”
They can also build up in animals and people over time, raising concerns about possible health risks. Removing them from water has become one of the biggest environmental challenges facing scientists and water treatment facilities.
To tackle this problem, the researchers created specially designed iron oxide nanoparticles. Iron oxide is essentially a form of rust, but at the nanoscale, these particles have unique magnetic properties. The team modified the surface of each particle so it could attract and bind to many different types of PFAS instead of targeting only one specific chemical.
Once the PFAS molecules attach to the nanoparticles, the cleanup process becomes simple. A magnet is used to pull the particles, along with the trapped pollutants, out of the water.
Rather than designing a system for only a few well-known PFAS compounds, the researchers wanted a technology capable of removing as many members of this large chemical family as possible. This broad approach could make the method useful in many different types of contaminated water.
The study also expanded the technology to address another growing environmental concern: fluorine-containing microplastics. These tiny plastic particles can be released from products such as waterproof outdoor clothing during washing and are also found in certain cosmetics. The researchers showed for the first time that their magnetic nanoparticles could capture not only dissolved PFAS molecules but also these microscopic plastic particles.
Another advantage of the technology is its flexibility. By changing the surface chemistry of the iron oxide particles, the researchers can tailor them to target different pollutants.
Some versions of the nanoparticles can even be regenerated and reused several times after the contaminants have been removed, making the process more sustainable and cost-effective. The particles themselves are also considered non-toxic and can be produced on a larger scale.
To demonstrate that the technology works outside the laboratory, the team tested it using real-world water samples. These included contaminated drinking water, river water, wastewater from soil cleanup projects and wastewater produced by washing outdoor clothing.
The results were encouraging. In contaminated drinking water, the researchers reduced PFAS concentrations by 87%, bringing the levels below Germany’s new safety limit of 100 nanograms per liter. The system also successfully removed fluorine-containing microplastics from the water.
The researchers believe their magnetic nanoparticle technology could become a versatile platform for future water treatment.
By tackling both dissolved forever chemicals and microscopic plastic pollution in a single process, the method offers a promising new approach for improving water quality and reducing the environmental impact of some of today’s most persistent pollutants.
