#microplastic pollution

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♻️🌊💪 Over 9,000 pounds of marine debris have been removed from the Kauai coastline! Every year, abandoned or discarded fishing nets, plastics, and other debris wash up on Kauai’s shores, endangering and entangling marine wildlife. Through a series of nine helicopter-assisted missions, volunteers from the Surfrider Foundation’s Kauai Chapter were able to clear thousands of pounds of debris from the island’s most remote and rugged shoreline!

Microplastics are now a ubiquitous part of our daily physical reality. These minuscule fragments of degrading plastic now suffuse our air, our soil, the food we eat and the water we drink. They’re being detected everywhere researchers look, from Antarctic sea ice to human brains. As scientists develop a better idea of where microplastics are accumulating in the environment, they’re just beginning to understand how these pollutants affect one of the most essential and widespread kingdoms of life on Earth: plants. A new study, published on Monday in the Proceedings of the National Academy of Sciences USA, reveals how microplastics hinder photosynthesis across a wide range of plant species—including crucial food crops. “It’s really scary,” says Marcus Eriksen, a marine scientist at the 5 Gyres Institute, a nonprofit plastic pollution research organization, who was not involved in the study. The researchers found that the presence of microplastics (plastic particles that are less than five millimeters in size) can reduce photosynthesis by as much as 7 to 12 percent, on average. That could range from 6 to 18 percent in terrestrial crops, 2 to 12 percent in marine plants such as seaweed and 4 to 14 percent in freshwater algae. “The exposure to microplastics was not surprising at all,” Eriksen says. “What surprised me was the level of impact.” A generalized reduction in photosynthesis at such a scale could have major implications for the global food supply, according to the study’s researchers.

When the Black Death struck Europe in the Middle Ages, the fundamental values that held society together broke down. Husbands and wives abandoned each other and mother’s abandoned their children. This void of ethics that overtook the population is described in Boccaccio’s Decameron, considered a masterpiece of Italian prose and a documentary of life during that time. The book describes the…

A new way to decompose microplastics could help clear waterways of these tiny bits of trash, which may pose health risks to people and other animals.

Water treatment plants typically aren’t equipped to filter out microplastics, such as exfoliating beads or flakes broken off larger pieces of garbage, like water bottles (SN: 8/9/14, p. 9). Those pesky particles can take decades to break down naturally, but new nanomaterials that produce plastic-degrading chemicals could break down this detritus much more quickly. In preliminary tests, the nanomaterials cleansed some water samples of about half their microplastic content in mere hours, researchers report online July 31 in Matter.

In the future, water treatment facilities that employ these nanomaterials may not only help prevent new microplastic pollutants from entering the environment, but also potentially remove the particles from polluted waterways.

This water purification method uses nitrogen-coated carbon nanotubes. When mixed with a compound called peroxymonosulfate, the nanotubes generate chemicals known as reactive oxygen species, which crumble microplastics into smaller chemical components. Heating the water speeds up this process. Manganese embedded within each nanotube made the tubes magnetic, allowing them to be fished out of water using magnets for reuse.

NANOSIZE SPRING The MVPs of the new water cleanup technique are tiny carbon nanotubes (one shown in this scanning electron microscopy image), which are twisted into spirals for increased sturdiness. When these nitrogen-coated nanocoils are mixed with a compound called peroxymonosulfate in water, they produce chemicals that break down microplastics. CREDIT:J. KANG ET AL/MATTER 2019

Jian Kang, a chemical engineer at Curtin University in Perth, Australia and colleagues tested their technique on 80-milliliter water samples contaminated with microplastic particles. Carbon nanotube treatment in water warmed to 120° Celsius for eight hours reduced the amount of microplastic in the water by about 30 to 50 percent.

Chemical by-products of this microplastic decomposition, such as aldehydes and carboxylic acids, aren’t major environmental hazards, says Long Chen, an environmental engineer at Northeastern University in Boston not involved in the work. Kang’s team, for example, found that exposing green algae to water containing the microplastic by-products for two weeks didn’t harm the algae’s growth.

“There is a whole battery of tests” that could further gauge the environmental risks of this technique, says Bart Koelmans, an environmental scientist at Wageningen University & Research in the Netherlands not involved in the work. Future experiments could investigate effects on other major players in water ecosystems, including phytoplankton, zooplankton and fish.

Using heat to facilitate microplastic breakdown may not be feasible for purification plants that need to process lots of water quickly, Chen says. But Kang and colleagues are now working to refine their nanotubes to break down microplastics more efficiently without the help of high temperatures.