Could This Dutch Invention Help Tackle Plastic Pollution in America's Waterways?

Amsterdam’s Westerdok looks like many other outlets to the city’s historic canals. But look past the familiar boats and birds, and there is a distinct pattern in the water not found elsewhere in the city: a diagonal line of whiter water. That’s because an innovative “curtain,” known technically as a Bubble Barrier, lies below the surface.

On the bottom of the waterway is a perforated tube which pumps air out, directing plastic to the surface. The natural flow of water then carries plastic litter to the Bubble Barrier’s catchment system, an aluminum trap on one side of the waterway, to prevent it from making its way to the North Sea. The current catch—laminated restaurant menus, food wrappers, even a selfie stick—demonstrated that well.

The Bubble Barrier at Westerdok was the company’s first, installed in 2019, but the technology has since been installed in other waterways in the Netherlands. And now, for the first time, it looks like the United States may also be getting a Bubble Barrier, in the Grand River in Lansing, Michigan. The Bubble Barrier in Amsterdam relies on bubbles of air to create a barrier of sorts to stop the spread of particles like plastic.

Other companies have employed similar curtains to contain oil spills, guide fish migration and even mitigate underwater noise. But using this type of barrier for plastic is particularly useful. According to Jordy Wolfand, a civil engineer at the University of Portland, it effectively functions as a boom.

But the Bubble Barrier sends plastic debris upward and then catches it. OceanTherm, a company based in Norway, develops bubble curtains to reduce impacts from hurricanes and tropical cyclones. These weather events obtain their energy from a warm ocean surface; the rising bubbles circulate cold water to the surface, cooling it down.

So far, the company has deployed a pilot in Norway. Weighing in on the Great Bubble Barrier’s work, OceanTherm’s chief technology officer Olav Hollingsaeter says, “It’s a very good thing to stop plastic in the rivers from getting out to the sea.” The fact that it’s minimally invasive makes it especially apt for busy channels, like the one at Westerdok. Amsterdam’s Bubble Barrier collects about 175 pounds of inorganic dry debris, per month, ranging from one millimeter to one meter in size.