RMIT University says it has developed a magnetic water treatment material that can be manufactured more efficiently while removing micro- and nano-plastics and some PFAS (per- and polyfluoroalkyl substances), with researchers positioning the technology as a step towards practical wastewater treatment applications.
According to RMIT, the invention builds on the team’s 2022 research into microplastics removal by extending its performance to much smaller particles and more complex wastewater conditions.
The university said the material is produced using a room-temperature manufacturing process that increases output fivefold while reducing the use of costly inputs.
First author Dr Muhammad Haris from RMIT’s School of Engineering said the research addressed an important challenge in water treatment.
“Our material is designed to remove micro- and nano-plastics quickly,” Haris said.
Laboratory testing found the material removed more than 95 per cent of micro- and nano-plastics, including particles as small as 30 nanometres, within one hour. RMIT said around 80 per cent of contaminants were removed in the first 15 minutes, matching contact times commonly used in water treatment plants.
The university also reported that the material removed more than 95 per cent of tested contaminants, including mercury, chromium, copper, dyes and ibuprofen, and performed across plastics such as polyethylene, polypropylene and polyester in both fresh and saline water. Early-stage testing also showed removal of large PFAS molecules.
Lead researcher Professor Nicky Eshtiaghi from RMIT’s School of Engineering said the ability to capture nanoscale plastics distinguished the technology.
“There is currently no effective solution for removing nano-plastics at scale,” Eshtiaghi said.
The research team also tested the material in industrial laundry wastewater, which RMIT described as a significant source of microplastic pollution from synthetic fibres. According to the university, the material removed more than 88 per cent of polyester microfibres while continuing to remove dyes despite the presence of surfactants and organic matter.
A prototype system developed with Canadian company One Eye Industries combined the adsorbent with magnetic separation technology, allowing the treatment material to be recovered and reused after treatment.
Co-lead researcher Associate Professor Nasir Mahmood from RMIT’s School of Science said the findings demonstrated the material’s potential in practical settings.
“It worked in realistic water conditions, handled mixed pollutants and could be recovered efficiently,” Mahmood said.
Roger Simonson, founder and inventor of One Eye Industries, said recovering treatment materials had been a major obstacle to commercial deployment.
“Industry has been waiting for a practical way to move microplastics and emerging contaminants removal out of the laboratory and into real treatment environments,” Simonson said.
“The challenge isn’t only capturing these particles, it’s recovering the treatment material quickly and reliably after it has done its job, without creating a new waste stream.”
RMIT said it is working with Geelong-based Indigenous-owned company Fire and Test Australasia to investigate potential stormwater and wastewater treatment applications, including in community settings, while also collaborating with Australian company Star Water Group, whose customers include organisations in the United States.
Eshtiaghi said the researchers had focused on making the technology suitable for wider adoption.
“Our goal was to make the technology effective, practical and affordable at scale,” she said.
“This includes ensuring the material can be recovered, reused and integrated into existing treatment systems.”
The study, Scalable room-temperature synthesis of a MOF-based magnetic adsorbent for rapid simultaneous removal of PFAS and micro-nanoplastics, has been published in the Chemical Engineering Journal.
