We have a problem with plastic. That novelty that was going to make our lives easier has become an ecological nightmare. The real problem is that we ingest a huge amount of microplastics each year and it has become such a huge problem that we have found them in archaeological remains, in blood, in breast milk and even in testicles.
Eliminating them has become a priority and the key may be in a filter called Ct-Cel that promises to eliminate up to 99.9% of these microplastics. What is it made of? Made of squid bone and cotton. More or less.
The filter. The study has been published in Science and it is signed by researchers from Wuhan University, in China. It details how Ct-Cel is a fibrous supramolecular biomass filter created thanks to the combination of chitin, a derivative of squid bone, and cellulose derived from cotton. The researchers, as we read in ScienceAlertstate that “this biomass fibrous framework shows excellent absorption performance of polystyrene, polymethyl methacrylate, polypropylene and polyethylene terephthalate.”
Efficient. The most curious thing is that it acts as if it were a living organism. “The affinity for various microplastics is attributed to the transformation of multiple intermolecular interactions between the different microplastics and the CT-Cel,” the researchers detailed. This means that the filter has a wide variety of bonding reactions between its parts, allowing an adaptation to better “trap” those varieties of plastic that range from 100 nanometers to three microns.
Something that stands out is that it can eliminate 98 to 99.9% of these types of microplastic in real tests in water from agricultural irrigation, lakes, coastal areas and stagnant waters, maintaining a high capture efficiency (between 95.1% and 98.1%) after five absorption cycles. Now, they also comment that the presence of some chemicals in the water reduces the absorption capacity.
And what are those mechanisms to trap particles? Molecular exchange as the forces of Van der Waalsthe electrostatic attraction of particles or the simplest: their physical interception.
In the fourth cycle we already see that the properties decrease, but even so the percentage of trapped microplastics is very high.
Next steps. Both chitin and cellulose had already been positioned as interesting elements for filtering and eliminating contaminants in water, but the real challenge for the researchers was to combine them. It is something that required manipulation to break down the internal structure of each component and then reconstruct said combined structure.
Now, the authors also point out that this is a filter in a very early stage of development. Despite the potential exhibited, it is necessary to do more tests, and on a larger scale, before carrying out the research that dictates whether or not it is viable to produce it on a commercial level.
Promising. And something key, beyond the efficiency in capturing microplastics, is that both cellulose and chitin are components that are easily found in nature, so they are economical and respectful of the environment. We will see how these tests progress, but any glimmer of hope that will help us with the million tons of plastic waste, welcome.
Images | Science, Inkwina, Betty Wills
In Xataka | Tap water is full of microplastics and we don’t know what effect they have in the long term
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