The new technique, developed by scientists at Hong Kong Polytechnic University, uses bacterial biofilms (a sticky substance created by microorganisms) to trap microplastic particles.
The biofilm is then processed and dispersed, releasing the plastic particles for processing and recycling.
Microplastics are an extremely problematic phenomenon. They pose a serious risk to food chains and human health.
“They are not easily biodegradable, where they are preserved in ecosystems for prolonged periods,” says the researcher Yang Liu. This results in the absorption of microplastics by organisms, and their retention along the food chain.
Tiny sponges that have invaded everything. They are burying us under a mountain of poison.
Due to its enormous absorbency, microplastics can absorb toxic pollutants, such as pesticides, heavy metals, and drug residues in high concentrations.
“This leads to biological and chemical toxicity for organisms in ecosystems and for humans after prolonged involuntary consumption,” confirms the researcher from the University of Hong Kong.
Microplastic: around the waist
Microplastics are an insidious threat. It is difficult to remove even from purification plants, which do not stop its unwanted release into the environment. However, this new method could represent a turning point.
How does the technique developed by the Hong Kong team work?
More specifically, the researchers used the bacterium pseudomonas aeruginosa to capture microplastic in a bioreactor.
The biofilms of pseudomonas aeruginosa cause the microplastic particles to clump together, eventually causing them to sink. In bioreactors, this makes the microplastic more convenient to collect.
Once captured and sunk into the bioreactor, researchers "unhook" the microplastic from the biofilm using a dispersal gene.
Results?
Liu explains that this method “allows a detachment of microplastics from the biofilm matrix. An otherwise difficult and expensive operation, which is now possible and also allows material to be recovered for recycling.
Imagine this anti-microplastic method directly in water treatment plants
Microplastics are plastic particles less than 5 mm in diameter. They can enter the environment through a number of sources including breaking larger pieces of plastic, washing synthetic clothing, breaking car tires and plastic waste directly from industry. Current methods for disposing of microplastics, such as incineration or landfill storage, are limited and have major disadvantages.
The next steps of the research, which was published in the Chemical Engineering Journal, are moving the proof-of-concept from the laboratory to a real environment.
Liu and colleagues hope that the technique will eventually be used in wastewater treatment plants to help stop the leak of microplastics into the oceans.
