Magnetic springs that hook onto microplastics and break them down can end the scourge of plastic pollution in the world's seas
- Experts can decompose microplastics with nitrogen-laced carbon nanotubes
- These are short-lived chemicals that cause a chain reaction in the plastics
- Long molecules are then divided into small, harmless segments that dissolve
- The research, by staff at the University of Adelaide, was published in the journal Matter
An ingenious way has been developed to free rivers and seas from microplastics – crucial, without harming microorganisms.
Study senior author Shaobin Wang, professor of chemical technology at the University of Adelaide, explained that microplastics, although often invisible to the naked eye, & ubiquitous & um. pollutants.
He said that some, such as the exfoliating beads in popular cosmetics, are just too small to be filtered out during industrial water treatment. Others are produced indirectly when larger debris such as soda bottles or tires weather the sun and sand.
But with the help of small spiral, carbon-based magnets, researchers in Australia have found a way to purify the plastic waste that poses a global threat to the environment – with harmful health consequences for humans, fish and animals.
An ingenious way has been developed to free rivers and seas from microplastics – crucial, without harming microorganisms
HOW DOES IT WORK?
To dissect the microplastics, the research team had to generate carbon nanotubes with nitrogen-coated.
These cause chain reactions that cut the various long molecules that make up microplastics into small and harmless segments that dissolve in water.
Shaped like feathers, the carbon nanotube catalysts removed a & # 39; significant & # 39; fraction of microplastics in just eight hours, while they themselves remained stable in the harsh oxidative conditions required for the degradation of microplastics.
Prof Wang said: & # 39; Microplastics adsorb organic and metal pollutants as they travel through water and release these hazardous substances into aquatic organisms when they are eaten, causing them to accumulate all the way in the food chain.
& # 39; Carbon nanosprings are strong and stable enough to break down these microplastics into compounds that are not such a & # 39; n threat to the marine ecosystem. & # 39;
To dissect the microplastics, the research team had to generate short-lived chemicals, called reactive oxygen species, which cause chain reactions that cut the various long molecules that make up microplastics into small and harmless segments that dissolve in water.
But reactive oxygen species are often produced using heavy metals, such as iron or cobalt, which are dangerous pollutants in themselves.
So the researchers found a greener solution in the form of carbon nanotubes with nitrogen to stimulate the generation of reactive oxygen species.
In the form of feathers, these removed a & # 39; significant & # 39; fraction of microplastics in just eight hours, while they themselves remained stable in the harsh oxidative conditions required for the degradation of microplastics.
Prof Wang said that the rolled-up shape increases stability and maximizes the reactive surface.
And as a bonus, by absorbing a small amount of manganese, buried far from the surface of the nanotubes to prevent it from leaching into water, the miniscule sources became magnetic.
Pollutants: every year, tons of small plastic waste – pictured here under the microscope – are not recycled, which may mean they end up in marine ecosystems
Project leader Dr. Xiaoguang Duan, a chemical technology researcher in Adelaide, said: & # 39; Having magnetic nanotubes is particularly exciting as it makes it easy to collect them from real wastewater streams for repeated use in environmental remediation. & # 39;
Because no two microplastics are chemically the same, the researchers said their next steps will be to ensure that the nano fibers work on microplastics of different compositions, shapes and origins.
Prof. Wang says they also intend to rigorously confirm the non-toxicity of chemical compounds that act as intermediates or by-products during the decomposition of the microplastics & # 39 ;.
The researchers also say that those intermediates and by-products can be used as an energy source for microorganisms that currently tease the polluting plastics.
Prof. Wang added: & # 39; If plastic contaminants can be reused as food for algae growth, it will be a triumph for using biotechnology to solve environmental problems in ways that are both green and cost efficient. & # 39;
The findings were published in the journal Matter.
WHAT ARE MICROPLASTICS AND HOW DO They ENTER OUR WATERWAYS?
Microplastics are plastic particles of less than five millimeters (0.2 inches).
They have made headlines in recent years because improper disposal has resulted in tons of waste entering the ocean.
Every year, tons of plastic waste is not recycled and treated correctly, which can mean that it ends up in marine ecosystems.
Although it is unclear exactly how they end up in the water, microplastics can penetrate through simple clothing and carpets that tear daily.
Tumble dryers can also be a source, especially if they are vented in the open air.
Plastic has not been breaking down for thousands of years and it is estimated that there are already millions of plastic waste in the oceans. This number is expected to rise.
Studies have also shown that 700,000 plastic fibers can be released into the atmosphere with every wash cycle.
Current water systems are unable to effectively filter out all microplastic contamination due to the varying particle size.
The amount of plastic waste in the world's oceans will outweigh fish by 2050 unless the world takes drastic measures to further recycle, a report released in 2016 revealed.
More than 80 percent of & # 39; the world's tap water is contaminated with plastic, according to research published in September 2017.
The US has the highest infection rate of 93 percent, followed by Lebanon and India, experts from the University of Minnesota found.
France, Germany and the UK have the lowest levels, but still reach 72 percent.
In total, 83 percent of the water samples from dozens of countries around the world contain microplastics.
Scientists warn that microplastics are so small that they can penetrate organs.
Bottled water may not be a safer alternative because scientists have found contaminated samples.
It has been found that beings of all shapes and sizes have consumed the plastics, directly or indirectly.
Previous research has also shown that microplastics absorb toxic chemicals, which are subsequently released into the intestines of animals.
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