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It’s inspired by – fish …
Wastewater from household laundry has become a growing focus for scientists studying plastic pollution. Each wash releases countless synthetic fibers that are too small to see but difficult to contain. Now, a team in Germany says nature may offer a solution.
Researchers at the University of Bonn have developed a washing machine filter inspired by fish anatomy, reporting early results that suggest it could sharply cut microplastic pollution before it reaches sewers.
A hidden source
Studies have long identified washing machines as a major contributor to microplastics, with fibers shedding from clothing during routine cycles. According to researchers at the University of Bonn, a single four-person household can release hundreds of grams of these particles annually.
Much of that material is trapped at wastewater treatment plants in sewage sludge. When the sludge is later used as fertilizer, the fibers can be spread across farmland, allowing plastics to re-enter the environment, the researchers say.
Limits of filters
Manufacturers have experimented with filters to capture fibers before wastewater leaves the machine, but success has been limited.
“The filter systems available so far, however, have various disadvantages,” said Dr. Leandra Hamann of the university’s Institute for Organismic Biology in an article on the University’s website. She added:
“Some of them quickly become clogged, others do not offer adequate filtration.”
Seeking alternatives, Hamann and her colleagues turned to biology rather than conventional engineering.
Lessons from fish
Some fish species, such as sardines and anchovies, feed by filtering particles from water using their gill arches. The Bonn team studied this structure closely and used it as a template for a new filter design.
“We took a closer look at the construction of this system and used it as the model for developing a filter that can be used in washing machines,” said Dr. Alexander Blanke, who led the research.
The gill system relies on a funnel shape that guides particles along a surface rather than forcing them directly into a flat screen, helping prevent blockages.
Promising results
In laboratory tests and computer simulations, the prototype removed more than 99 percent of plastic fibers while remaining resistant to clogging, according to findings published in npj Emerging Contaminants. The researchers say the design is mechanically simple and could be produced at low cost.
Captured fibers are regularly suctioned out and compacted into a small pellet that could be disposed of with household waste.
The University of Bonn and the Fraunhofer Institute UMSICHT have applied for patents in Germany and across the European Union. The team hopes appliance manufacturers will adapt the design for commercial machines, reducing a source of pollution increasingly linked to human health concerns.
Sources: University of Bonn, npj Emerging Contaminants
