Researchers at Flinders University say they have developed an adsorbent material that removed more than 98% of short- and long-chain PFAS—including hard-to-capture short-chain variants—in laboratory flow-through tests using model tap water. The approach embeds nano-sized molecular cages into mesoporous silica and, in the experiments reported, could be regenerated while remaining effective over at least five reuse cycles.
A research team at Flinders University’s College of Science and Engineering has reported a new adsorbent designed to remove per- and polyfluoroalkyl substances (PFAS)—a class of highly persistent compounds often called “forever chemicals”—from water.
According to a Flinders University news release distributed via EurekAlert, the project was led by ARC Research Fellow Dr. Witold M. Bloch and focuses on short-chain PFAS, which the researchers describe as especially difficult to capture with existing treatment approaches.
“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,” Bloch said in the release.
The technique uses a nano-sized molecular “cage” that binds PFAS by forcing the molecules to aggregate inside its cavity—an interaction Bloch described as unusually strong compared with traditional adsorbent materials. The team embedded these cages into mesoporous silica, which the release says typically shows no PFAS-binding properties on its own.
First author Caroline V. I. Andersson, a PhD candidate in chemistry at Flinders, said the group first studied how PFAS bind inside the cage at the molecular level and then used those findings to design the adsorbent.
In laboratory testing described in the release, the material removed up to 98% of PFAS at “environmentally relevant concentrations” in model tap water. Bloch said the adsorbent remained highly effective after at least five reuse cycles, which the researchers say supports potential use in final-stage water-treatment “polishing” steps.
The work was published in Angewandte Chemie International Edition, EurekAlert reported, under the title “Efficient Removal of Short-Chain Perfluoroalkyl Substances by Cavity-Directed Aggregation in a Molecular Cage Host.”
