A fish-inspired filter could help tackle world’s microplastic crisis

Microplastics have become one of the most common forms of pollution in today’s world in a stealthy manner, penetrating every field of an ecosystem, food chain, and the lives of human beings. However, scientists from Bonn University have come up with a solution to prevent a substantial percentage of pollution at the point of origin using a solution inspired by nature. The research of these scientists has been published in a reputed journal named npj Emerging Contaminants under a publication named "Nature Portfolio." They developed a filtration technique inspired by a fish capable of eliminating more than 99 per cent of microplastics present in wastewater generated from washing machines, which leads to a major cause of pollution worldwide.

The study was featured on the online scientific website "Nature." Since then, the study was picked up by websites such as "ScienceDaily," as well as the University of Bonn website, a repository of the university’s research findings, emphasising the global significance of the research findings. The filter is modelled after the arrangement of the "gill arches" of filter-feeding fishes, such as the anchovy or sardine. They have evolved over millions of years to effectively filter microscopic substances from water without clogging.
 
“We have thus found a combination of parameters that enable our filter to separate more than 99 per cent of the microplastics out of the water but not become blocked,” said Dr Leandra Hamann, lead author of the research, as cited by ScienceDaily. The ease with which the design can operate has provided the advantage that it can easily be implemented through the following household appliances.
Washing Machines: A Major but Overlooked Source of Pollution
Plastic microbeads are small particles of plastic less than five millimetres in size. They result either from the breakdown of larger plastic products or are shed directly from manufactured materials, such as synthetic textiles. According to Britannica and National Geographic, plastic pollution is often thought to be an ocean and industrial problem, but scientists indicate that household activities are a major source.
 
Synthetic fibres in fabrics such as polyester, nylon, and acrylic release thousands of microscopic fibres during every wash cycle. Indeed, studies cited in npj Emerging Contaminants show that a single household washing machine can spew out hundreds of grams of microplastic fibres every year, with laundry wastewater being among the most important ways in which microplastics enter sewage systems.

Once they are released, the micro-fibres sometimes evade the usual washing filters and, in some circumstances, wastewater treatment facilities. Those that are filtered often tend to accumulate within the sludge and are often utilised as agricultural fertiliser, effectively circulating the microplastic back into the ecosystem.
 
This problem is directly targeted by the filter used at the University of Bonn, whereby the fibres are intercepted before they leave the home. This is done through the university’s cone-shaped, semi-cross-flow filter that causes the water to move across the fibres before flowing out.
 
“In the course of their evolution, these fish have developed a method comparable to cross-flow filtration," explained Dr. Alexander Blanke, co-author of the study, in a statement prepared by the University of Bonn. “We have adopted this natural model to develop a filter usable for washing machines."

Microplastics in Blood and Why Early Intervention Matters
Microplastics no longer stay out of the human body. Various recent studies have confirmed their existence in human blood, which engenders a broader level of concern among scientists and experts in public health. As confirmed by broader microplastics research referenced in the Nature publication, these particles may enter the human body through drinking water, food, air and household dust.
 
The WHO, however, admits that the growing concern of human exposure to microplastics is real and, though long-term health implications have not been conclusively reached, there is evidence of microplastics being so permeating in the environment that urgent attention and preventive action on it is warranted.

In a similar vein, environmental scientist Dr Sherri Mason, who is a prominent expert in the field of plastic pollution, has cautioned us about the presence of plastic pollution, declaring, “We are now living in a world where plastics are everywhere — and that includes our bodies." Her argument has been underscored through the strong warning she has repeatedly issued regarding the challenges facing us, as we face an emerging public health-related concern.
 
Likewise, Professor Tamara Galloway, an Ecotoxicologist with the University of Exeter, has suggested how the human body might react to the presence of microplastics, as it is posited to do so “in complex ways.” She explained, “The concern is not just the plastic particles themselves, but the chemicals they carry and the way they may trigger inflammatory responses once inside the body.”
 
This has further been evidenced by the reporting of National Geographic, who have highlighted the use of microplastics as carriers of toxic additives and environmental pollutants. “Plastics were never designed to end up inside living organisms,” they observe, “yet they are now being found in blood, lungs and even placental tissue.”

It is indeed due to this reason that prevention of source pollution has come to represent a major research priority worldwide. Tests carried out in a laboratory to determine the viability of using a filter inspired by fish, as revealed in npj Emerging Contaminants, showed that 99.6 per cent of these plastic fibres can be held in a mere five per cent of total water volumes as waste.
 
“This filter modelled after nature has no elaborate mechanics and should consequently be inexpensive to produce," said Hamann. This invention has already been submitted for a patent in continental Europe and in Germany. It is also believed that appliance manufacturers will integrate this feature into their future washers.
 
For one, as the global rate of plastic production escalates, experts are already cautioning that the removal of such microplastics that are already widely distributed is almost impossible. Innovations such as the aforementioned filter that intervene long before the spread of the contamination are critical to easing one of the biggest challenges that the planet is facing in the 21st century.