What is ferrofluid and how does it remove microplastics?

Ferrofluid is a colloidal liquid containing suspended iron oxide nanoparticles coated with a surfactant. When added to water containing microplastics, the hydrophobic surfactant coating causes ferrofluid droplets to adhere to microplastic surfaces. An external magnet then draws the iron-rich fluid — along with the captured plastics — out of the water.

How effective is the ferrofluid method at removing microplastics?

In Fionn Ferreira's experiments, the method achieved up to 87% removal efficiency across eight types of microplastics tested in various water conditions, including sea water and fresh water. The method is effective on microfibers, fragments, beads, and films.

Who invented the ferrofluid microplastics removal method?

The method was invented by Fionn Ferreira, an Irish scientist from West Cork, who won the Google Science Fair Global Grand Prize in 2019 for this research at age 18. He is now a doctoral researcher at ETH Zürich in the Barnes Group.

Can ferrofluid be removed from water after the extraction process?

Yes. Ferrofluid is itself magnetic, so it can be fully extracted from the water using a magnet after the microplastic removal step. The ferrofluid can potentially be separated from the collected microplastics and reused, making the process more sustainable.

What types of microplastics can this ferrofluid method remove?

Ferreira's experiments tested eight microplastic types including polystyrene, polyethylene, polypropylene, PET, and PVC — covering the most common morphologies found in ocean and fresh water: fibres, fragments, beads, and thin films.

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Every litre of ocean water contains thousands of invisible microplastic particles. This is how Fionn removed them.

Google Science Fair Grand Prize · 2019

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The
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