A new system to clean the water sources of the microplastics that contaminate them without damaging the microorganisms that live in them has been developed by Australian researchers.
Using small coil-based carbon-based magnets, the researchers of the University of Adelaide (Australia) hope to clean more effectively seas and rivers.
To eliminate microplastics, short-lived chemicals called reactive oxygen species are required, which trigger chain reactions that in turn cut the various long molecules that form the microplastics into small and harmless segments that dissolve in water. The problem with this method is that reactive oxygen species are often produced using heavy metals such as iron or cobalt, whichthey are pollutants by themselves.
To overcome this environmental pitfall, these heavy metals have been replaced by carbon nanotubes mixed with nitrogen. Shaped like springs, carbon nanotube catalysts removed a significant fraction of microplastics in just eight hours. The spiral shape increases stability and maximizes the reactive surface area, as explained by the lead author Shaobin wang, Professor of Chemical Engineering at the University of Adelaide:
Carbon nanocaps are strong and stable enough to break down these microplastics into compounds that do not pose a threat to the marine ecosystem (...) Having magnetic nanotubes is particularly exciting because it makes it easy to collect them from real wastewater streams for their repeated use in environmental remediation.
As there are no two chemically identical microplastics, researchers will soon focus on ensuring that this new technique works on microplastics of different compositions, shapes and origins.