A filter-free prototype removed over 85% of microplastics in one pass—but what happens to the captured plastic?
Fionn Ferreira developed a method that mixes contaminated water with a magnetic liquid called ferrofluid. The liquid binds to microplastic particles, allowing magnets to separate the mixture from the water.
The European Patent Office’s 2023 profile says the prototype it described removed more than 85% of microplastics in a single pass. It also says no disposable filter is needed and nearly all of the ferrofluid can be recovered for reuse.
That could eliminate one waste stream associated with filter-based capture, but “filter-free” does not automatically mean zero waste. This was a prototype result, not evidence of equal performance in every water source or at municipal scale. The captured plastic also still needs a safe and verifiable end route.
From a zero-waste perspective, what should be tested first: how many reuse cycles the ferrofluid survives, how much escapes during treatment, or what ultimately happens to the recovered microplastics?
Source: "European Patent Office – Fionn Ferreira: Removing microplastics from water"