These Islands Are Sucking Up Pollution From The Water They’re Floating In

Floating islands that double as water treatment plants keep water clean without sullying nice views.

Wetlands are known for their ability to clean water: their thick vegetation traps excess nutrients (which cause algae blooms) and heavy pollutants, and help keep waterways free and clear. But, of course, many rivers and lakes don’t have wetlands anymore. They tend to be the first casualty when planners look to add more real estate or shipping.


That’s where these green islands come in. Like floating water treatment plants, they combine the greenery you’d see in a traditional wetland with a few pieces of man-made technology. They’re from a Scottish company called Biomatrix and they’ve already been deployed successfully in several countries, including Finland, China, and the Philippines.

“The native plants planted in our floating islands are selected for their benefits to local biodiversity, their intricate and deep growing root systems, and their beauty,” says Biomatrix’s operations coordinator Elle Adams. “The plant roots grow down into the water and develop beneficial aquatic biofilms, which cleanse the water through the breakdown, sorption, and metabolic transformation of nutrients and impurities.”

Biofilm is the green gunk you see on rocks by the ocean or growing on an outside drain. It’s beneficial bacteria that eats up organic matter and passes on cleaned water. Wastewater plants have used biofilm filters for more than a century. Biomatrix is just encouraging it to proliferate in the natural environment, both by re-introducing plants and adding its own “dynamic media columns.” These are wool-like tentacles with large surface areas are perfect for biofilm production. “The dynamic media is made from a synthetic fiber that is woven into a column using stainless steel wire and is specially designed to offer the maximum amount of surface area available for bacterial colonization,” Adams says.

Almost as importantly, the islands look nice, encourage wildlife both above and below, and can be used as recreational spaces. They’re also adaptable. Biomatrix produces 21 formation types, and each is modular, meaning you can have any size of platform you like, Adams says.

There are more sophisticated ways of cleaning waterways, though they tend to be more expensive than Biomatrix’s solution. Its biomimicry approach shows that natural processes can be as efficient as anything human engineering can devise.

About the author

Ben Schiller is a New York staff writer for Fast Company. Previously, he edited a European management magazine and was a reporter in San Francisco, Prague, and Brussels.