Scientists developed a new method to trap “forever chemicals” in water using nanosized molecular cages.

Researchers at Flinders University are now reportedly capable of removing up to 98 percent of  per- and polyfluoroalkyl substances (PFAS) from water. For an industry under rising pressure to confront chemical use and wastewater impacts, the advance points to a potential new tool for cleaning up production processes.

Though the fashion industry has phased out long-chain PFAS, such as perfluorooctanoic acid (PFOA)—a chemical known for accumulating in the environment and linked to potential health risks—many manufacturers now promote short-chain alternatives as safer options for water repellency. Small hitch, however: short-chain chemicals are more mobile and harder to filter than long-chain PFAS.

“While some long-chain PFAS can be partially removed using existing water treatment technologies, the capture of short-chain PFAS—which are more mobile in water—remains a major unresolved challenge,” said Dr. Witold Bloch, the project leader and an ARC Research Fellow with the Adelaide, Australia-based university’s College of Science and Engineering.

Until now, such chemicals have slipped through traditional treatment systems, ending up in groundwater and drinking supplies worldwide.

“We discovered that a nano-sized cage captures short-chain PFAS by forcing them to aggregate favorably inside its cavity,” Bloch said. “This unusually strong binding mechanism is different from that of traditional adsorbent materials.”

Here’s how the trap works: The cage is designed to “selectively capture” (see: force) PFAS molecules to “clump together” within its cavity. Fundamentally, the cages are embedded in mesoporous silica—a specialized, man-made form of the glass-like material, designed with a highly organized system of tiny, uniform pores—thereby creating a purportedly powerful adsorbent material. To that end, its reusability is high.

Unlike one-time-use filters, the material retains its effectiveness after at least five cycles of use—presenting, potentially, a cost-effective solution for industrial-scale water treatment.

“We first conducted in-depth studies of how PFAS bind within the cage on the molecular level,” said first author Caroline Andersson, a PhD candidate in chemistry at Flinders University. “That allowed us to understand the precise binding behavior and then use that knowledge to design an effective adsorbent for PFAS removal.”

The findings, published in “Angewandte Chemie International Edition,” represent a step toward more effective strategies for tackling PFAS pollution—even if they fall short of a comprehensive solution.