A University of Adelaide-led research team has developed a new approach to purging water sources of the microplastics that pollute them without harming nearby microorganisms.
Plastic waste finds its way into oceans and rivers poses a global environmental threat with damaging health consequences for animals, humans, and ecosystems.
The researchers have developed a technique to break down the microplastics using tiny coil-shaped carbon-based magnets. Their work is published in the journal Matter.
“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, 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.”
Although often invisible to the naked eye, microplastics are ubiquitous pollutants. Some, such as the exfoliating beads found in popular cosmetics, are simply too small to be filtered out during industrial water treatment. Others are produced indirectly, when larger debris like soda bottles or tires weather amid sun and sand.
The research is a collaboration between University of Adelaide, Curtin University, Edith Cowan University and Guangdong University of Technology in China.
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 make up 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 and thus unsuitable in an environmental context.
To get around this challenge, the researchers found a greener solution in the form of carbon nanotubes laced with nitrogen to help boost 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. The coiled shape increases stability and maximises reactive surface area. As a bonus, by including a small amount of manganese buried far from the surface of the nanotubes to prevent it from leaching into water, the minute springs became magnetic.
“Having magnetic nanotubes is particularly exciting because this makes it easy to collect them from real wastewater streams for repeated use in environmental remediation,” says project co-leader Dr Xiaoguang Duan, Research Fellow in the University of Adelaide’s School of Chemical Engineering and Advanced Materials.
As no two microplastics are chemically quite the same, the researchers’ next steps will centre on ensuring that the nanosprings work on microplastics of different compositions, shapes and origins. They also intend to continue to rigorously confirm the non-toxicity of any chemical compounds occurring as intermediates or by-products during microplastics decomposition.
The researchers also say that those intermediates and byproducts could be harnessed as an energy source for microorganisms that the polluting plastics currently plague. “If plastic contaminants can be repurposed 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,” Professor Wang says.
Learn more: BREAKING DOWN MARINE PLASTIC POLLUTION
The Latest on: Microplastics
via Google News
The Latest on: Microplastics
- UN: Don't worry about drinking microplastics in wateron September 6, 2019 at 10:38 am
GENEVA (AP) — The World Health Organization says the levels of microplastics in drinking water don't appear to be risky, but that research has been spotty and more is needed into their effects on the ...
- Major environmental challenge as microplastics are harming our drinking wateron September 6, 2019 at 7:02 am
Plastics in our waste streams are breaking down into tiny particles, causing potentially catastrophic consequences for human health and our aquatic systems, finds research from the University of ...
- Earth 8: Microplastics are polluting beaches at an alarming rateon September 4, 2019 at 6:02 pm
SAN DIEGO — Microplastics, which never fully biodegrade, can be found everywhere – in the sand, in the water, and at San Diego beaches. Now, researchers at Scripps Institute of Oceanography say ...
- More Than Half a Century of Microplastics Are Buried in Layers of Sediment, Like Synthetic Fossilson September 4, 2019 at 4:48 pm
18 Great Big Things That Are Both Big and Great ...
- WHO Examines Health Risks, Mitigation of Microplasticson September 3, 2019 at 11:55 am
The publication ‘Microplastics in drinking water’ is the WHO’s first effort to examine the potential human health risks from exposure to microplastics. By improving wastewater treatment, the report ...
- Microplastics detected in human stool sampleson September 3, 2019 at 9:35 am
(HealthDay)—Microplastics have been detected in stool samples of healthy volunteers, according to research published online Sept. 3 in the Annals of Internal Medicine. Philipp Schwabl, M.D ...
- Microplastics Found In The Ocean And In Human Poopon September 3, 2019 at 12:39 am
There are two bits of microplastic news from this weekend. One of them is garbage, and the other is poop. First the garbage. On Saturday, 52-year-old French long-distance swimmer Benoît Lecomte and ...
- Plastic is infecting your gut: Average person accidentally ingests more than 73,000 pieces of microplastics every year, damning study revealson September 2, 2019 at 11:00 pm
We are all eating around 73,000 tiny bits of plastic every year through our food and drink, according to a new study. These are inadvertently entering our mouths, guts and faeces as scientists ...
- Microplastics turning up in human stoolon September 2, 2019 at 2:58 pm
(Reuters Health) - Tiny bits of plastic may be getting into our bodies via the air we breathe and the food we eat, a new study suggests. Researchers who examined stool samples from eight people from ...
- Detection of Various Microplastics in Human Stoolon September 2, 2019 at 2:05 pm
Disclosures: Dr. Schwabl reports nonfinancial support from AbbVie, Gilead Sciences, Falk, and Roche outside the submitted work. Dr. Bucsics reports support from AbbVie and Bristol-Myers Squibb outside ...
via Bing News