Fionn Ferreira, from Ballydehob in West Cork, Ireland, lives near the seashore. He started becoming increasingly aware of plastic pollution entering the oceans. He was alarmed to find out how many microplastics enter our wastewater system and consequently, through them, the beautiful ocean by his home. Being the smart and passionate teenager that he was, this shocking reality inspired him to try and find out a way to remove microplastics from the water before they even reached the sea.
His curiosity led him to win an international science award for his project, which removed microplastics from water. Ferreira, 18 years old, was announced the overall winner of the 2019 Google Science Fair—a prestigious annual global science competition open to students aged 13 to 18—which earned him a $50,000 (about €45,000) bursary!
The Project
Microplastics are plastic particles less than 5mm in diameter. Typically, such microplastics, or microbeads, are used in soaps, shower gels and facial scrubs to exfoliate the skin, as well as in toothpaste and abrasive cleaners. However, they can also be the byproduct of bigger plastics breaking down into smaller fragments. His project examined a new method for extracting them safely from the water in a quick and sustainable way.
Currently, there is no screening or filtering for microplastics that takes place in any European wastewater treatment centers, which means that fish and other creatures mistake the tiny scraps of plastic for food, and, from there, the beads are integrated into the food chain.
His first challenge was how to measure the concentration of microplastics in water. For this, he built a spectrometer. He explains how in his chemistry class at school he learned about how like charges attract like charges—i.e., non-polar vegetable oil would attract non-polar plastics in the environment of water. He had read about Dr. Arden Warner, who has developed a method for cleaning up oil spills using magnetite powder (naturally occurring iron oxide) and thought that maybe he could combine oil and magnetite to create a solution that would allow him to remove plastics from water.
What Ferreira ultimately did was use ferrofluids, a combination of oil and magnetite powder, and magnets to extract microplastics from the water. He was able to remove over 87% of microplastics from water samples using his method in 1,000 tests. “The method used was most effective on fibres obtained from a washing machine and least effective on polypropylene plastics,” he said.
Conclusion
Ferreira points out that there “is no doubt that the most effective way to reduce microplastic pollution in oceans is to use less plastics and ensure that plastics used can be recycled and separated to prevent them from entering our wastewater, but the reality is that more and more of the products we use contain plastics and potentially degrade into microplastics before entering our wastewater.”
Which is why it is so important to find efficient and effective ways of extracting microplastics from wastewater before they reach our watercourses and ultimately our oceans. Ferreira says that his proposal could “form the basis for an effective way of extracting microplastic from water” and that “the next step is to scale this up to an industrial scale.” A newer approach using living microrobot swarms that trap microplastics shows how magnetically guided bacteria can actively capture particles in water and then be retrieved magnetically.
