Igloo-shaped devices treat sewage in wastewater lagoons
Bio-Domes, inexpensive igloo-shaped, pollution-eating devices, can clean up sewage just as effectively as multimillion-dollar treatment facilities for towns outgrowing their waste-treatment lagoons, according to a new study.
Kraig Johnson, chief technology officer for Wastewater Compliance Systems, will present the study Jan. 13 in Miami during the Water Environment Federation’s Impaired Water Symposium. It also will be published in the symposium program.
Wastewater treatment in small, rural communities is an important and challenging engineering task. Proper treatment includes disinfection and the removal of unwanted pollutants. Most rural communities rely on wastewater lagoons as their primary method of treatment because they are simple and inexpensive to operate. Lagoons are large holding ponds in which sewage is held for a month to a year so that solids settle and sunlight, bacteria, wind and other natural processes clean the water, sometimes with the help of aeration.
But as communities grow and pollution discharge requirements become more stringent, typical wastewater lagoons no longer can provide adequate treatment. Until now, the only alternative for these communities was to replace lagoons with mechanical treatment plants, which can be expensive to build and operate. Mechanical plants treat water in 30 days or less, using moving parts to mix and aerate the sewage, speeding the cleanup. They require electricity, manpower and sometimes chemicals.
Johnson and his research team developed the Bio-Dome when he worked as a research assistant professor of civil and environmental engineering at the University of Utah. The Bio-Dome was designed to address the problem faced by communities outgrowing their sewage lagoons. The device provides a large surface area on which bacteria can grow, providing the microbes with air and a dark environment so they consume wastewater pollutants continuously with minimal competition from algae.
The new study outlines results of a pilot project conducted in 2009 at Salt Lake City’s Central Valley Water Reclamation Facility. Wastewater Compliance Systems obtained an exclusive license from the University of Utah to commercialize Bio-Domes, so the devices now have been deployed in six states in either full-scale installations or pilot demonstrations. Every installation showed that Bio-Domes provide treatment that meets pollution control requirements.