Scientists in Australia have developed magnetic springs that can decompose microplastics in the world’s seas and rivers.
Their work has been published today (July 31) in the journal Matter and outlines how tiny coil-shaped carbon-based magnets ‘purge’ water sources of microplastics that pollute them without harming nearby microorganisms.
Microplastics are pieces of plastic under five millimetres in length and come from a variety of sources, including from larger plastic debris that degrades into smaller and smaller pieces.
There are also microbeads, a type of microplastic, which are very tiny pieces of manufactured polyethene plastic.
To decompose the microplastics, the researchers had to generate short-lived chemicals called reactive oxygen species, which trigger chain reactions that chop the various long molecules that makeup microplastics into tiny and harmless segments that dissolve in water.
However, reactive oxygen species are often produced using heavy metals such as iron or cobalt, which are dangerous pollutants in their own right.
To get around this challenge, the researchers found a greener solution in the form of carbon nanotubes laced with nitrogen to help boost the generation of reactive oxygen species.
Shaped like springs, the carbon nanotube catalysts removed a ‘significant fraction’ of microplastics in just eight hours while remaining stable themselves in the harsh oxidative conditions needed for microplastics breakdown.
‘Microplastics adsorb organic and metal contaminants as they travel through water and release these hazardous substances into aquatic organisms when eaten, causing them to accumulate all the way up the food chain’ says senior author Shaobin Wang, a professor of chemical engineering at the University of Adelaide.
‘Carbon nanosprings are strong and stable enough to break these microplastics down into compounds that do not pose such a threat to the marine ecosystem,’ he added.
Our understanding of the damage that microplastics cause marine ecosystems have been highlighted in several studies this year.
Researchers at Anglia Ruskin University found that microplastics are affecting the ability of mussels to attach themselves to their surroundings which is having a devastating impact on ocean life.
Another report by the Instutition of Mechanical Engineers revealed that 35% of microplastics released into the world’s oceans come from synthetic textiles.
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