Audi Developing Filters For Microplastics

German auto maker rolls out new green initiatives – including filters for urban runoff – at the 2021 Greentech Festival in Kraftwerk Berlin

The Audi Environmental Foundation is developing optimized sediment filters for urban runoff in collaboration with the Technical University of Berlin, Department of Urban Water Management and other partners. The URBANFILTER project launched September 2020 and is expected to run for three and a half years.

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The filters are designed to catch contaminant particles as close as possible to their point of origin – even before they are washed into the sewer system by rainwater, the researchers said.

Tire and road wear particles are generated as a result of every car ride. An estimated 110,000 tons ends up on the streets in the form of microplastics every year in Germany alone. From there, particles scatter into the environment via the wind, or are washed by the rain via urban runoff and sewers – usually untreated – into the soil, rivers, and oceans.

Not only car tires, but also bicycle tires, the wheels of skateboards, and even shoe soles produce these fine particles. There’s no way to completely avoid them. “But we can do something preventively to ensure that less microplastic enters and pollutes the environment,” Rüdiger Recknagel, Managing Director of the Audi Environmental Foundation, said.

Audi microplastics filter concept illustrationThe sediment filters have a modular design and can be adapted to different road situations, traffic volumes, and other forms of pollution.  For example, constant braking and restarting causes tires to lose more wear particles than on an unobstructed straight stretch of road.

“In addition, we want to capture other pollutants that accumulate on and around streets –and on sidewalks, as well as  natural particles, such as sand, leaves and pollen from trees,”  Joachim Wloka, Audi project manager responsible for the URBANFILTER project.

The sediment filters are divided into three zones: street, sewer, and drain.

The researchers are developing nine different modules for different road and traffic conditions, Up to three different modules can then be combined to achieve the best result depending on the location, they said.

In the uppermost area (street), this may be a special runoff channel or appropriate asphalt.  In the sewer itself, larger solids are filtered out, via a leaf basket or what is known as a filter skirt. The lowest area (drain) is all about fine filtration.

The research team is currently testing a magnet module. In early tests, the magnets trapped particularly fine particles without clogging.

The modules are still, for the most part, in the planning stage. Nevertheless, the partners are planning to test them in real-world scenarios before the end of the year.

© Scrap Tire News, July 2021