Water filters with nanoscale channels selectively remove stubborn “eternal chemicals”

Traditional water filters struggle to remove smaller PFAS molecules, but the new Monash designed filter changes it. Researchers at Monash University have developed water filter membranes that effectively remove small PFA molecules, overcoming the important challenges faced by traditional water filters.

The researchers designed beta-cyclodextrin (βCD)-modified graphene oxide (GO-βCD) membranes using nanoscale channels that selectively retain PFA while passing water. This work has been featured in Journal Acs Nano.

PFAs, commonly known as “Forever Chemicals,” are widely used in industrial and consumer products, and are environmentally sustainable and pose potential health risks. PFA contamination in Australia’s drinking water and waterways has raised concerns for communities, governments and water service providers. A federal investigation is currently examining the scale of use and impact across the country.

In tests, the Monash membranes are significantly more than traditional polyamide membranes, typically removing only about 35% of the short-chain PFA. The team also confirmed that the membrane prevents PFA movement and creates an energy barrier that effectively blocks contamination.

The first author and Dr. Monash candidate Eubert Mahofa highlighted the importance of this breakthrough in PFAS filtration.

“PFA is difficult to manage because it can easily dissolve in water and spread far from the original source. Contamination makes it contain and difficult to repair. Removing small PFA molecules from water was a major hurdle for existing filters.”

“Our approach solves this by allowing water to flow efficiently, while also eliminating and focusing these harmful chemicals, making it a powerful candidate to compensate for PFA destruction techniques.”

Dr. Sally El Meragawi, a collaborator on the project, highlighted the potential impact of membranes on global water treatment strategies.

“By combining advanced materials with Smart Chemistry, we have created a highly efficient way to tackle this global pollution problem. The unique structure of the membrane allows even the smallest PFAS molecules to be effectively removed,” said Dr. Elmelagawi.

“Our approach paves the way for future membrane technologies tailored to remove targeted contaminants in drinking and wastewater treatment applications. It is also an attractive method to retain key nutrients in the water and use them with traditional nanofiltration systems.”

The membranes were manufactured using shear alignment printing, a scalable technique that allows for industrial scale production of graphene oxide films.

Traditional polyamide membranes struggle to block smaller PFA molecules. In contrast, tests and simulations showed that Monash designed membranes form a strong barrier that effectively prevents PFA passage even at varying temperatures, while maintaining efficient water flow.

Professor Mainak Majumder, director of the Australian Research Council’s Research Hub, highlighted the broader implications of the technology by the advanced manufacturing hub (AM2D) with 2D materials that supported the work.

“This breakthrough in PFAS filtration could revolutionize the way PFA contamination is managed globally, with applications ranging from landfill leachate treatment to industrial wastewater purification,” Professor Majumder said.

“Our technology opens up new possibilities for developing sophisticated nanofiltration membranes tailored to remove specific molecular species by selecting the appropriate binding chemistry.”

The longstanding collaboration between Monash University, Clean Teq Water and its graphene-centric subsidiary Nematiq supports the development and commercialization of innovative membrane technologies.

Peter Voigt, CEO of Clean Teq Water and Nematiq, said, “The development of graphene membranes modified for PFAS removal represents an exciting advance in water treatment. Nematiq looks forward to working closely with Monash University to bring this innovative technology to the market.

“We are excited to continue our partnership with Nematiq to commercialize this promising graphene film technology. Such collaborations are key to translating research into real-world impacts,” Professor Majumder said.