Scientists have built a reusable magnetic material that can remove more than 95% of microplastics and nanoplastics from water within an hour, showing early promise in removing some PFAS
Scientists at Australia’s RMIT University have developed a reusable magnetic material that can remove more than 95% of microplastics and nanoplastics from water within an hour and shows early promise in combating certain PFAS.New water treatment technology captures plastic particles as small as 30 nanometers while removing toxic heavy metals, pharmaceutical residues and industrial dyes. The findings were published in the Journal of Chemical Engineering, titled “Scalable room-temperature synthesis of MOF-based magnetic adsorbents for rapid simultaneous removal of PFAS and micro- and nanoplastics.” The paper was co-authored by first author Dr. Muhammad Haris and co-authors Professor Nicky Eshtiaghi and Associate Professor Nasir Mahmood of RMIT University.
Clean quickly under real-world conditions
In laboratory tests, magnetic particles eliminated more than 95% of tiny plastic fragments in fresh and salt water, including polyethylene, polypropylene and polyester. The material captures 80% of contaminants within the first 15 minutes, directly matching the rapid cleaning times used at commercial water treatment plants.“Our material is designed to rapidly remove micro- and nanoplastics,” said Dr Harris, a researcher at RMIT University’s School of Engineering.In addition to plastics, the powder removes more than 95% of heavy metals such as mercury, chromium and copper, as well as ibuprofen and fabric dyes. Early tests also show that the material can capture larger molecules of PFAS, a toxic chemical that breaks down very slowly in nature. However, researchers note that the removal of PFAS is still in its early stages.“There are currently no effective solutions for large-scale removal of nanoplastics,” Professor Eshtiaj said. She points out that capturing nanoscale plastics is crucial because these tiny pieces can easily pass through ordinary filters.
Solve recovery problems with magnets
A major problem with water cleaning powders of the past was removing the material from the water after absorbing contaminants. To solve this problem, RMIT University teamed up with Canadian company One Eye Industries to pair water-absorbent powder with industrial magnets.The combined system was tested against industrial laundry wastewater, a major source of contamination from synthetic plastic fibers. Despite high levels of soap, chemicals and organic dirt, the material removed more than 88% of polyester microfibers as well as liquid dyes. Once the cleaning process is complete, the magnets easily draw the powder out of the water so it can be used again.“The industry has been waiting for a practical way to move the removal of microplastics and emerging contaminants from the laboratory to a real treatment environment,” said Roger Simonson, founder and inventor of One Eye Industries. “The challenge is not only to capture these particles, but also to quickly and reliably recycle the disposed material after the job is complete without creating a new waste stream. Combining high-performance contaminant capture with proven magnetic separation creates a more robust path to real-world deployment. “Associate Professor Mahmoud added: “It can work in realistic water conditions, handle mixed contaminants, and can be recycled efficiently.”
Production costs reduced by 75%
The new design marks another big step forward for the team since its initial microplastic removal breakthrough in 2022. By switching to a room-temperature manufacturing process that uses cheaper raw materials, the researchers increased yields fivefold while reducing costs by about 75 percent. Since magnetic powder can be cleaned and reused multiple times, operating costs are lower.“Our goal is to make this technology effective at scale, practical and affordable,” Professor Eshtiaghi said. “This includes ensuring materials can be recovered, reused and integrated into existing treatment systems.”
Business partnerships and global expansion
RMIT is currently working with Fire and Test Australasia, a local company based in Geelong, Victoria, to test the system on stormwater and community water networks.“Cleaning and protecting water is very important to Indigenous communities who are the custodians of their lands and waterways,” Eshtiaj noted.The university is also partnering with Australian company Star Water Group to enter markets in the United States and Europe, where regulators are enacting stricter rules on the amount of plastic and chemicals in town water supplies.Simonson noted that the technology shows strong real-world potential in garment factories, industrial plants, town water systems and local stormwater facilities.
Coping with the growing environmental crisis
Microplastics and nanoplastics have become a growing environmental threat as evidence grows that they are present in rivers, oceans, drinking water and food. These tiny pieces are shed from larger plastic waste, synthetic clothing, and factory processing, making them nearly impossible to catch with regular filters.Nanoplastics are particularly risky because their tiny size allows them to pass through cell walls and accumulate in organisms. Ordinary water treatment plants rely on sand, gravel and alkaline sedimentation tanks that are simply not built to capture nanoscale particles.By creating a material that can physically absorb nanoplastics and then pull them out using magnets, the RMIT team has provided a practical way to capture these tiny particles before they end up in public rivers and oceans. Governments across Europe and North America are enacting tighter limits on factory runoff, but simple tools to handle both plastic debris and chemical waste are becoming critical for treatment plants.
