In 2022, a study confirmed the presence of microplastics in the blood flow of more than twenty blood donors.
Microplastics are those plastic fragments smaller than five millimeters in size, which also usually contain additives that are dangerous to health. They come from the industry because they are used in cleaning products, paints. and other substances, either because they are the result of the degradation of larger plastics, such as bags, bottles or other plastic containers.
Microplastics are classified into two groups according to how they are produced, thus primary microplastics are plastic particles that are already manufactured with a size of less than 5 millimeters and are used in a wide variety of products, such as cosmetics, personal care products, paints, varnishes and cleaning products, while secondary microplastics are plastic particles that are produced from the degradation of larger plastic objects, due to the degradation suffered by the action of sunlight, water, wind and marine organisms.
Primary microplastics are released into the environment through the production, use and disposal of products that contain them, for example, polyethylene microspheres are used in some cosmetic products such as facial scrubs and toothpastes, which They reach the water when products are rinsed. Secondary microplastics are released into the environment through the degradation of larger plastic objects, and are often carried by wind or ocean currents to the oceans, where they become microplastics.
The existence of microplastics in the sea causes it to be eaten by many marine species and through them transferred to the food chain, being present throughout the chain through their corresponding predators, until reaching us, in the same way. .
Therefore, the treatment of microplastics has become an issue of utmost concern, since the UN has confirmed the presence of these elements in more than 25 species of fish, and even in honey , salt, or beer.
In order to find a way to clean the water of these elements, a group of Indonesian researchers from the Institut Teknologi Sepuluh Nopember presented at the Acoustical Society of America, a prototype capable of concentrating the microplastics present in a stream of water, using ultrasound, which pushes the microplastics towards the center of a pipe, in which they could later be collected.
The initial prototype would be capable of cleaning more than 50% of the microplastics contained in a stream with a flow rate of up to 150 liters per hour.
Ultrasound is a form of acoustic energy above the audible range of human hearing, produced by the vibration of a material, such as a piezoelectric crystal. When ultrasound is applied to a liquid, the vibrations cause the formation of air bubbles, these bubbles grow and collapse rapidly, producing shock waves that can break up water molecules.
In the case of microplastics, the shock waves produced by ultrasound can break plastic particles into smaller pieces. These smaller pieces can then be filtered or separated from the water. Currently, there are several ways to apply ultrasound to remove microplastics from water.
One way is to use a device that generates ultrasound through a nozzle, so that contaminated water is passed through the nozzle, and the shock waves produced by the ultrasound break up the plastic particles. Another way to apply ultrasound is to use a device that generates ultrasound in a water tank. The contaminated water is passed through the tank, and the shock waves produced by the ultrasound break up the plastic particles.
The efficiency of the ultrasound technique in removing microplastics depends on several factors, such as the size of the plastic particles, the frequency of the ultrasound, and the power of the device. Overall, the technique has been shown to be effective in removing plastic particles up to 50 microns in diameter.
The ultrasound technique has several advantages over other microplastic removal techniques, so firstly, it is a non-toxic technique that does not produce polluting chemicals and secondly, it is an efficient technique that can remove a large amount of microplastics from water. . Thirdly, it is a relatively cheap and easy technique to implement.
Ultrasonic cleaning aims to prevent its impact from having greater consequences, with the seas being the destination of up to 12 million tons of microplastics per year, where they have caused verified damage to turtles, birds and other species marine.
Although it is still a technology to be investigated, it promises to provide an effective way to minimize the damage caused by the presence of these microplastics in water, however, to treat seawater, we will have to see, the repercussion of this technology on fauna, and if any, the way to counteract it, if possible.
In any case, we must be aware of the importance of reducing the consumption of plastics on a daily basis, minimizing its use, as well as returning industries to the use of recyclable or easily biodegradable materials, such as wood, paper, natural resins or cork, leather and natural fiber fabrics, in order to avoid the increase and continue the proliferation of microplastics in natural ecosystems, and avoid the great negative impact it causes on all types of animal species, as long as we do not have fully biodegradable substitute materials for plastic.
In any case, filtering the sea is a lot of filtering…
In another vein, but continuing with ultrasounds, at the Polytechnic University of Valencia, a group of researchers are also using this technology in order to filter the water from wastewater treatment plants, managing to eliminate up to 40 % of microplastics existing in these waters.
