Igloo-Shaped Devices Eat Sewage and Treat Wastewater
Inexpensive igloo-shaped, pollution-eating devices nicknamed "Poo-Gloos" can clean up sewage just as effectively as multimillion-dollar treatment facilities for towns outgrowing their waste-treatment lagoons, according to a new study.
"The results of this study show that it is possible to save communities with existing lagoon systems hundreds of thousands, if not millions of dollars, by retrofitting their existing wastewater treatment facilities with Poo-Gloos," says Fred Jaeger, chief executive officer of Wastewater Compliance Systems, Inc., which sells the "Poo-Gloo" under the name Bio-Dome.
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 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-or 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 are 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 Bio-Domes provide treatment that meets pollution-control requirements.
Lynn Forsberg, public works director for Elko County, Nevada, recently started using Bio-Domes in a county sewage treatment lagoon system in Jackpot, Nev., after a successful pilot test. "Our alternative was to go with a full-blown [mechanical] treatment plant that would cost about four times as much and be much more labor intensive," he says.
How Bio-Domes Work
Bio-Domes use a thriving bacterial biofilm to consume pollutants. Two dozen or more igloo-shaped Poo-Gloos are installed on the bottom of the lagoon, fully submerged and arrayed in rows. Each Bio-Dome consists of a set of four progressively smaller, plastic domes nested within each other like Russian nesting dolls and filled with plastic packing to provide a large surface area for bacterial growth.
Rings of bubble-release tubes sit at the base of every Bio-Dome and bubble air up through the cavities between domes. The air exits a hole in the top of each dome. As air moves through the dome, it draws water from the bottom of the lagoon up through the dome and out the top.
Each Bio-Dome occupies 28 square feet of space on the bottom of a lagoon while creating 2,800 square feet of surface area for bacterial growth. The combination of large surface area, aeration, constant mixing and a dark environment that limits algae make Bio-Domes capable of consuming pollutants at rates comparable with mechanical plants.
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