Wave Goodbye To Microplastics
Article Written By: Sophia Lin
Date Published: June 9th, 2024
For scientists, filtering microplastics out of water is a huge challenge, and these issues have been posing a major threat. With scientists starting to understand the consequences and effects these tiny particles have; they have been researching a solution that would revolutionize and put a stop to environmental pollution: using ultrasound waves to get rid of microplastics from the water. Although they have a harmless appearance, these plastics, which range from decimals to 5 millimeters in size, present a danger to both human and marine life/health. These plastics are inside multiple types of waterbodies like rivers, lakes, oceans, and even the water we drink. A report, prepared by Dalberg, shows that people could be ingesting plastic, equivalent to the size of a credit card, each week. However, it isn’t an easy task to eliminate these small pollutants, it is more challenging than you may think.
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Picture of microplastics. Credit to Depositphotos.
Ultrasound waves aren’t the regular type of sound waves that humans hear every day, they are special due to them averaging over 20 kilohertz. At this level of high frequencies, the normal human ear cannot hear the sounds these waves make. Not only that, but if these waves are placed into water, they can cause acoustic cavitation, which is the process of fast creation, expansion, and the bursting of bubbles in the liquid. The bursting of these bubbles results in concentrated energy and strong shear forces.
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By using ultrasound waves, they can produce energy that is generated from acoustic cavitation. When the bubbles explode, the shock waves and micro-jets can break the larger plastics into smaller pieces, making it easier to catch them. Along with the cavitation-induced turbulence, it allows the collection of microplastic particles, facilitating their merging into even bigger bunches. Filtration techniques can more effectively remove these clusters, improving the overall effectiveness of microplastic removal.
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This type of method to remove microplastics is still in the works, but early research has shown its possible success. The next step would be more research and experimentation, and improvement of the ultrasound treatment weaknesses (like the intensity/frequency/duration that aren’t perfected yet), which could make ultrasounds reach their maximum effectiveness and potential of removing microplastics. Combining this new technology with the current water treatments being used could ease its long-term adoption.
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Microplastic pollution continues to grow and while there are new methods, technology needs to be advanced as well to keep up. Ultrasound waves have the potential to grow to become better and show the amount of progression that has been made. This article was made to shine a light on the importance of using science to address environmental issues. If more research is done, it has the potential to improve water and the environment because of the potential thriving marine life and less-polluted ecosystems.
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Microplastics scattering in flowing water on the left side. The right shows with the soundwaves on, with the particles concentrating. Credits to Menake Piyasena.
CITATIONS
1. ACS Publications Chemistry Blog. (n.d.). Making waves: Removing microplastics from water with sound. https://axial.acs.org/earth-space-and-environmental-chemistry/making-waves-removing-microplastics-from-water-with-sound
2. Editor. (2023, May 20). Microplastics, Japan: The ultrasound technology that fights them. SEN Sustainability & Environment Network. https://www.sustainabilityenvironment.com/2023/05/21/microplastics-ultrasonic-technology-from-japan-foghts-them/
3. Removing microplastics from water with ultrasounds. IMNOVATION. (n.d.). https://www.imnovation-hub.com/science-and-technology/removing-microplastics-water/
4. YouTube. (2023, March 28). Pulsing ultrasound waves could someday remove microplastics from waterways. YouTube. https://www.youtube.com/watch?v=QBCNi75ZWKE