BERLIN—A joint industry-academia research project has developed filters the partners claim can prevent tire wear particles (TWP) and other environmentally harmful substances found in urban runoff from being washed into sewers.
The system "traps" dirt particles as close as possible to the location where they are generated, before rainwater can rinse them into the sewers, Audi Environmental—an autonomous research unit established a decade ago by German car maker Audi A.G.—said recently.
The project, a joint effort of Audi Environmental Foundation and Technical University of Berlin, was launched in September 2020, and initial field and lab tests have now demonstrated the efficiency of the system, the partners said.
The Urbanfilter, Audi said, was deployed earlier this year on a busy road in Berlin and "mastered" its first stress test during a series of storms in mid-February.
According to the company, an estimated 110,000 metric tons of tire particles are produced in Germany per year, due to everyday car use. From there, the particles are blown into the environment by the wind or washed by the rain as urban runoff through the sewers into the soil and rivers.
"Our goal is to take preventive actions wherever possible so that less microplastics get into the environment," Ruediger Recknagel, director of the Audi Environmental Foundation, said.
The filtering out of "ultra-fine particles", however, is still presenting the team of researchers with challenges.
"The system has already passed tests with ground tire rubber between 20 to 1,000 micrometres (µm) in size in conditions of light to medium rainfall," according to Daniel Venghaus, research associate in the department of Urban Water Management at TU Berlin.
Now the team is working on improving the filter performance when there is strong rainfall.
The filter deployed in Berlin will remain in place for a year for further field studies and the investigation of the behavior of genuine tire wear particles. Furthermore, initial discussions are already underway with the ADAC Driving Safety Center in Berlin-Brandenburg to install filters on its routes so as to gain a better understanding of the filtering of wear particles in different driving situations.