Magnetic Sponge Pulls Plastic Out of Wastewater

RMIT's reusable adsorbent strips microplastics and some PFAS from real wastewater, and it can be recovered and reused.

23 Jul 2026

A material that can be pulled back out of water with a magnet after doing its job: that is the pitch behind RMIT University's latest water treatment breakthrough. The team's new adsorbent rapidly removes micro and nanoplastics, along with some PFAS compounds, from contaminated water. Published in the Chemical Engineering Journal, the work builds on the group's 2022 discovery, now extended to smaller particles and messier wastewater.

The trick lies in tailored iron oxide particles with engineered surface chemistry, which let the material be pulled out magnetically once treatment is done. Tests in industrial laundry wastewater, a notorious source of synthetic microfiber pollution, removed more than 88 percent of polyester microfibers and dyes. Surfactants and organic matter in the water did not knock performance down.

A prototype pairing the adsorbent with magnetic separation technology from Canada's One Eye Industries showed the material could be recovered fast and reused multiple times. Co lead researcher Associate Professor Nasir Mahmood said the results held up under realistic water conditions, even with mixed pollutants in the mix.

PFAS removal is the newer, shakier part of the story. Tests showed the material catches larger PFAS molecules, but researchers are careful to flag this as early stage work, well behind the more established microplastics performance. Recovering treatment material after use has historically stalled promising lab technologies before they ever reach commercial deployment.

The timing helps. UK water companies face growing pressure to tackle PFAS, nutrients and microplastics in surface runoff, with environmental frameworks placing more weight on pollutants that conventional filtration was never built to catch. Reusable adsorbents like this one offer a possible path toward water reuse without the steep operating costs of single use filtration media.