Fionn Ferreira Used Magnets to Pull Microplastics From Water
Fionn Ferreira won the 2019 Google Science Fair with a prototype method that uses ferrofluid and magnets to remove microplastics from water.
Fionn Ferreira found inspiration on Ireland’s coast, where plastic fragments were visible but the smallest particles were nearly impossible to collect.
2019
Google Science Fair win
Ferrofluid
Core material
Magnets
Separation method
The idea
Ferreira experimented with ferrofluid—a magnetic liquid containing iron oxide—and discovered that it could bind with microplastic particles suspended in water.
A magnet could then pull the ferrofluid and attached plastic from the sample without relying on a conventional filter.
A science-fair breakthrough
He ran extensive tests across different plastic types and reported high removal rates in controlled samples. The work won the 2019 Google Science Fair Global Grand Prize.
Prototype versus deployment
Laboratory performance is only the beginning. A practical treatment system must recover and reuse the ferrofluid, process large water volumes, work in complex wastewater and safely handle the captured plastic.
Ferreira has continued developing the technology with those scaling questions in mind.
Why the work matters
Microplastics are difficult to remove precisely because they are tiny and chemically varied. Ferreira’s method reframed the problem: instead of trapping each particle with a finer screen, make the particles temporarily magnetic.
Sources: Fionn Ferreira’s official profile, World Economic Forum
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