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Magnetic powder could be key to ridding ocean microplastics

When plastic pollution degrades into tiny fragments it can no longer be detected by wastewater treatment plants. A newly developed magnetic material, however, can effectively hoover up all forms of microplastic to be removed.

It may have only entered global discourse in the last few years, but people are now generally aware of the ecological threat posed by microplastics.

Split into two categories, primary microplastics are tiny items (typically smaller than 5mm) that have been designed for commercial use. We’re talking microfibres shed from clothing and other textiles, like fishing nets.

Secondary microplastics are those that appear due to throwaway plastic items breaking down within a natural environment, due to the sun’s radiation or ocean waves.

Most of this type is less than 1 micrometre in diameter, or 1,000 times finer than human hair meaning it is incredibly difficult to extract at wastewater treatment plants. There is, however, a burgeoning solution that is exciting ecological researchers.

A new powder has been developed specifically for absorbing this type of pollutant before it can toxify waterways, harm sea-life, and reportedly even end up in human blood.

In the last year, microplastics have also been documented in table salt, bottled water, fruits, vegetables, and packaged meat. Suffice to say, it’s quickly escalating from an ecological problem into a health one.

‘It’s a porous material with a special surface that can react with microplastics,’ says Nicky Eshtiaghi, lead researcher of the team the developed the idea. It’s also magnetic, meaning extraction is about as easy as it gets.

As it stands, methods for getting rid of these fragments aren’t exactly abundant. We’ve seen some novel ideas, including a 3D printed robo-fish designed by a student at the University of Surrey, but nothing has reached the scale capable of making a real dent.

Even industrial filters equipped with nano-sized technology either work extremely slowly, or fail to collect the smallest pieces. On the other hand, this new material gets to work within just an hour, and doesn’t discriminate with what’s being absorbed.

The proof of principle phase is now pretty much out of the way, and we know the nano-agent works. The real challenge of finding how to scale up the technology and how best to deploy it logistically, comes next.

Considering some eight million pieces of plastic enter the ocean every day, formulating one effective plan is nigh-on impossible. But that doesn’t mean we should stop trying.