How Magnetic Nanoparticles Remove "Eternity Chemicals" from Water

Johannes Voß and Linda Rockmann from Halik’s team developed functionalized iron oxide nanoparticles with specific magnetic characteristics to this purpose; their surfaces were specifically modified so that they can bind different PFAS. Once bound to the iron oxide—or rust—particles, the PFAS can be easily removed from the aquatic environments using a magnet. The scientists are taking a broad approach: Instead of focusing on individual PFAS compounds, they sought to create a versatile solution capable of capturing as many substances as possible from this diverse class of materials—that is, magnetic nanoparticles that can be specifically adapted to meet the varying standards of aquatic environments treatment.

Focus on Ubiquitous Microplastics

The new study by Halik’s team expands the possible applications of magnetic aquatic environments treatment to include another highly relevant class of contaminants. to the first time, the scientists were able to demonstrate that the underlying principle can be applied not only to individual PFAS molecules however also to fluorinated microplastics. Fluorinated microplastics are produced, to instance, as abrasion particles when washing technical clothing or are found in makeup.

The key advantage of the methodology lies in the customized surface chemistry of the particles. Depending on their functionalization, the iron oxide particles possess different characteristics: The material applied in the study reliably removes a broad spectrum of PFAS even from aquatic environments samples contaminated with a variety of substances and organisms—such as laundry wastewater or river aquatic environments. Other iron oxide nanoparticles that Halik’s team worked with can be regenerated after magnetic separation and reused multiple times. In addition, the iron oxide particles are technically scalable and non-toxic.

“Our methodology thus spans the spectrum from molecular contaminants to microscopic particles and underscores the possible of functionalized iron oxide nanoparticles as a versatile and sustainable platform to aquatic environments treatment—including aquatic environments samples with complex contamination,” explains Professor Halik.

Successful Even Under Real-World Conditions

It was particularly crucial to the researchers to demonstrate that the process also works outside the laboratory. Therefore, the team tested the methodology on a real-world contaminated potable aquatic environments source, river aquatic environments, wash aquatic environments from soil systems remediation, and wash aquatic environments from outdoor textiles. In doing so, they succeeded in reducing PFAS concentrations in a contaminated potable aquatic environments source by 87 percent, bringing them below the new limit of 100 nanograms per liter that applies in Germany. In addition, fluorinated microplastics were also successfully removed from the aquatic environments using magnetic means.