Team studies use of algae to purify wastewater, make fuel
Above: The CLEARAS algal treatment system under construction at the Village of Roberts, Wis. Photo: CLEARAS Water Recovery Inc.
A research team led by CEE associate professor Jeremy Guest has been awarded a grant of $2 million by the U.S. Department of Energy to study the use of algae to purify wastewater while simultaneously producing biomass for fuel production. Over the course of this three-year project, researchers will collaborate with a provider of algal treatment systems, a municipality that is implementing one, and colleagues at Northeastern University and the University at Buffalo, to better understand this system that promises to treat wastewater and produce fuel from a renewable supply of water, nutrients and sunlight.
Removing pollutants from wastewater is expensive and energy intensive. According to the U.S. Environmental Protection Agency, municipalities expend so much energy on water and wastewater facilities that just a 10 percent improvement in energy efficiency would save the U.S. $400 million and 5 billion kilowatt-hours a year. Algal purification systems offer an opportunity to save money and energy, while also producing raw materials for biofuel production. In addition, algal systems have the potential to remove certain contaminants more effectively than traditional purification systems.
“Algae remove nitrogen and phosphorus from wastewater by taking it up and using it to grow new cells,” Guest said. “This growth means there's more algae, which can then be removed from the treatment system and used as a renewable feedstock to produce biofuels.”
Phosphorus in particular can be removed to concentrations below 0.04 milligrams of phosphorus per liter with algal systems, which is far better than the typical 0.3 milligrams of phosphorus per liter left after many traditional biological treatment systems, Guest said.
For the field work portion of the study, the team will be partnering with CLEARAS Water Recovery Inc. and the Village of Roberts, Wis. CLEARAS has done pilot studies of these systems across the country and is completing construction of its first full-scale algal treatment facility in Roberts.
“Our goal is to advance our understanding of intensive – small footprint, really effective – algal wastewater treatment so we know how to optimize the design and control of algal wastewater treatment systems anywhere in the country, thereby increasing reliability of treatment, increasing biomass production and the quality for fuels, and reducing financial risk to utilities,” Guest said.