Chesapeake Bay Clean-Up Could Hinge on Algae

Patrick Kangas has helped work on everything from algae-based floating lake restorers to experimental algae turf scrubbers. Now, he is trying to prove-out and scale-up his algae turf scrubber so it might someday help clean up the Chesapeake Bay. Kangas, an associate professor at the University of Maryland, has developed a system that is based on the growing patterns of algae near coral reefs, with water pulsing through a wastewater cleanup system that acts as waves do in the ocean, to increase the growth rates of the algae.

Using solar-powered pumps, the system sends polluted water (from areas like that of the Chesapeake Bay) into a series of plastic troughs where algae is present and able to filter out the phosphorous or nitrogen in the water for use as a growth medium. Once a week, Kangas and his team from Maryland push the algal sludge created in the troughs to the end of the troughs, where it can dry for later use as an experimental biofuel feedstock by the university’s chemical engineers, who have already developed a process to produce algae-based biobutanol or ethanol.

“Algae sometimes are thought to be part of the problem in Chesapeake Bay and elsewhere because they respond quickly to pollution, and that is through uncontrolled growth.” Kangas says the idea with the algae turf scrubber, however, is to control the way algae works with nutrients like phosphorus or nitrogen.

“This system doesn’t just remove nutrients,” Kangas says. “It adds oxygen to the water.” The addition of oxygen to water is important, he adds, for places such as the Dead Zone in the Gulf of Mexico, where eutrofication has compromised ecosystems. Kangas has formed a new center at the University of Maryland in the hopes of commercializing his wastewater treatment technology. The design of the system was aided by an environmental consulting company Living Ecosystems.

“We’re really just taking what happens in nature and controlling it, and channeling it into the kind of ways that we want to use the algae, essentially, to work for us,” Kangas says.

—Luke Geiver