Student creates system that filters microplastics from water

A 16-year-old student from Brazil has created a low-cost filtration system that can be installed in sewage treatment plants.

Studies show that the treated water we drink already contains microplastics, particles smaller than 5 millimeters that can carry heavy metals that are harmful to humans and animals. By consuming water with these microplastics, a person can ingest around 120,000 particles per year.

Student Gabriel Fernandes Mello Ferreira, from Colégio São José, in Itajaí (Brazil), has created a filtering system that has proven to be 100% effective in retaining them. So effective that it will be used by a water treatment plant, responsible for 70% of Itajaí and Navegantes’ supply.

He explains that microplastics are generated by a process similar to weathering, when rocks and their minerals undergo physical and chemical changes caused by factors such as climate and terrain. When applied to plastic, improperly disposed waste breaks down into tiny pieces down to tiny particles. These particles eventually pass into the water of rivers, dams, from where water is collected for treatment and consumption.

According to Gabriel, the conventional treatment process involves several steps, such as settling, filtration, disinfection and fluoridation, which remove impurities from the water, but not to the point of retaining microplastics.


Research and solution.

The student recalls that during his research he was surprised to discover that a person can consume up to 121,000 microplastic particles per year.

This is largely due to the presence of microplastics in the treated water, as several studies show that treatment plants are unable to retain microplastics because they do not have a specific mechanism for these particles.

Gabriel Fernandes Mello Ferreira.

With the help of Professors Fernanda and Lenon, the student developed a microplastic retention mechanism that can be easily applied in water treatment plants.

With the pandemic, it was not possible to test the filter in sewage treatment plants and the solution found was to build a smaller model to simulate the results in an aquarium. The filter proved to be very effective, filtering out almost all plastic particles during the simulation.

Microplastics are less dense than water and therefore the filtration mechanism only filters the superficial part of the water table. The filter uses a skimmer which, through tubes, directs the water to a plastic cylinder with a 300µ nylon mesh bottom. This collector glass is the filter element, through which the water passes and the microplastics are retained in the mesh.

Gabriel Fernandes Mello Ferreira.

The mechanism can be easily integrated into the water treatment process at the sewage treatment plant, as no structural renovation is required. The installation is simple and the cost is very economical.



The microplastic filtering system project is one of the finalists of the 19th edition of the Brazilian Science and Engineering Fair (FEBRACE 2021), which takes place from March 15 to 26 through the virtual platform FEBRACE.

A total of 345 projects prepared by 716 students from 295 primary, secondary and technical schools across the country will be exhibited, with the participation of 482 teachers, who acted as project directors.

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