A San Diego-based tech startup has come up with an innovative way to fight destructive algae blooms and purify lake water, whilst also putting the removed algae to good use: making shoes.
Algae blooms are thick layers of algae that cover a water’s surface, choking off oxygen for other marine life and making the water undrinkable. Many things contribute to algae blooms, from pollution and fertilizer runoff to climate change increasing water temperatures.
Algae grows quickly when it has plenty of nutrients, but it doesn’t live very long. A growth spurt, or bloom, is followed by a high concentration of dead and dying algae that can turn toxic, resulting in mass die-offs of other marine life.
So, all in all, they are not good. Enter Bloom, a US-based company that harvests these algae blooms to create a foam that works particularly well in making footwear.
To utilize the algae, Bloom uses mobile harvesters that pump through the algae-heavy water, adding a water-resistant coagulant to make the algae clump together. Air bubbles push these clumps to the surface of the water in the harvesting tank, allowing it to be skimmed off. The water is then filtered and pumped back into the lake or river that it came from.
The harvested algae is then taken to one of Bloom’s facilities, where they squeeze all the water out and dry it using a solar-powered process. Once dried, the algae biomass is combined with other components to create a polymer.
Currently, Bloom has harvesting units in Missippi, Alabama, and around China, including Lake Taihu, a large freshwater lake in the Yangtze Delta plain, famous for its algae blooms. The lake is supposed to provide around 30 million people with fresh water, but low pollution regulations mean it is instead a hotbed for algae explosions. In 2007, nearly one-third of the lake was covered and the Chinese government had to shut down water collection as it wasn’t safe.
Bloom has been using their harvesting units there for two years, removing millions of pounds of algae. Now, they have teamed up with UK-based footwear company VivoBarefoot to create an amphibious shoe using the algae biomass foam from the lake.
According to the two companies, each pair of shoes will help recirculate 215 liters (57 gallons) of clean water back into its natural habitat and stop around 40 balloons worth of CO2 from being released into the atmosphere. The shoes will be available to buy this summer.
"We've already got more algae than we'll ever need," Bloom founder Rob Falken told Fast Company last year. "In China, Lake Taihu could produce enough algae for us to produce a pair of shoes for every man, woman, and child on this planet."