Humans are dirty animals. Wherever we step, we leave piles of trash that just doesn’t go away. World’s oceans are polluted with our microplastics – breakdown products of your food packages, plastic bags and other plastic stuff. Now a University of Adelaide-led research team found a way to purge water sources of the microplastics without harming nearby microorganisms.
And that is the big thing – you’re the one eating your own plastic. Inappropriately disposed trash ends up in water, where it is eaten by microorganisms. Those are then consumed by bigger animals and eventually end up on your dinner table in a form of seafood. Entire ecosystems are affected by our plastics and this situation is just getting worse. However, clearing microplastics from the environment is very difficult, especially if you are aiming to protect local microorganisms.
Microplastics themselves absorb organic and metal contaminants, making them even more dangerous to wildlife. However, scientists found that by using tiny coil-shaped carbon-based magnets they can break these microplastics down into compounds that do not pose significant risks. Researchers had to generate short-lived chemicals called reactive oxygen species. They are able to break long molecules of plastic, turning them into chemicals that dissolve in water. However, these d reactive oxygen species themselves are rather dangerous. This is why scientists turned to carbon nanotubes laced with nitrogen. They work like catalysts, removing a significant fraction of microplastics in just eight hours. Because they are coil-shaped, they are rather stable and have a maximised reactive surface area.
Scientists also added some manganese particles in the mix, making these nanotubes magnetic. Dr Xiaoguang Duan, project co-leader, said: “Having magnetic nanotubes is particularly exciting because this makes it easy to collect them from real wastewater streams for repeated use in environmental remediation”. This is great, but scientists are still not entirely sure how well this approach will work.
We use thousands of different kinds of plastics that later become thousands of different kinds of trash. This carbon nanotube method may not work with every kind of plastic there is. This is why scientists will have to perform more tests to find out if method is universal enough and will work reliably in nature.
Also, researchers would like to see if broken down microplastics could be used as an energy source for those microorganisms. Breakdown products could be harmless and serve as food for algae growth – that would be the real triumph of green biotechnologies.
Source: University of Adelaide