New approach uses algae to treat city wastewater
A more efficient system of wastewater treatment using algae will help communities meet increased regulations at a reduced cost.
Typically, municipalities use a bacterial process to treat wastewater. Algae can be used to treat wastewater, but the process normally requires a large area, making it infeasible for many metropolitan areas.
Iowa researchers developed a new way to cultivate algae in a continuous vertical loop, improving the efficiency of carbon dioxide and sunlight absorption and producing 10 times the biomass of a conventional algae system.
The research has gained the attention of officials in Greater Chicago, home of the world’s largest wastewater treatment system. Chicago is studying use of the new system at one of its water reclamation plants. The system could provide income for city budgets from the sale of fertilizer produced from harvested, dried and pelletized algae.
The system also may help much smaller communities address new regulations on limiting nitrogen and phosphorus emissions from water treatment. A lower-cost algae system for treating wastewater would avoid high-cost renovations to community wastewater treatment plants, typically paid for by taxpayers.