One way to remove microplastics from water is to encourage them to clump together into compounds that can be filtered – or, in the context of the 20-year-old Irish inventor Fionn Ferreira’s work, magnetized – out. Ferreira created a homemade ferrofluid – a magnetic mixture of oil and powdered rust – and successfully used it to remove 88% of microplastics from water samples. Ferreira’s efforts won him the top prize at the 2019 Google Science Fair. He hopes to incorporate his findings into a device compatible with existing filtration systems, such as those in wastewater treatment plants (most of which are unable to sufficiently filter out microplastics).
Dr Juan José Alava, an expert in marine eco-toxicology and conservation, believes the answer to the microplastics problem could already be in the environment. Alava studies organisms he calls “living vacuum cleaners”, including bottom feeders such as sea cucumbers, as well as the much smaller organisms that make up “epiplastic microbial communities”: strains of bacteria able to break down synthetic material, some of which originally evolved to metabolize naturally occurring polymers such as lignin and wax, and others which evolved to eat plastic garbage specifically.“The idea is to identify communities of bacteria and try to enhance them – not by incorporating a new mix of genes created by humans, but by stimulating them to break down plastic,” he says. When an organism can eliminate more plastic than it accumulates in its body or waste, it becomes “our best ally” in the fight against microplastics, says Alava.
Nanoplastics – as tiny as 0.1 micrometers in diameter – have long proven particularly difficult to remove from drinking and wastewater given their minute size, and they have been found to accumulate in the tissues of humans and other organisms. A new kind of water filter made from plant-derived nanocellulose mesh has been created by scientists at the VTT Technical Research Centre of Finland. The porous, colloidal structure of cellulose allows the material to bind to nanoplastics without using any chemical or mechanical interaction, says Tekla Tammelin, a research professor.