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New wastewater treatment for our green buildings? The Bio-Dome – also known as Poo-Gloo for its igloo shape – is a device that cleans wastewater using natural processes, and powered by a small amount of electricity that amounts to about one horse power per ten domes. Developed by Wastewater Compliance Systems, Inc., Bio-Domes use a combination of air, dark environment and large surface area to encourage the growth of a bacterial biofilm that consumes the wastewater pollutants. Each Bio-Dome consists of four nested plastic domes filled with plastic packing materials to provide a large surface area for bacterial growth. Rings of bubble-release tubes sit at the base of every Bio-Dome, bubbling air up through the cavities between domes. The air is exhausted through a hole in the top of each dome. As air moves through the dome, it also draws water from the bottom of the lagoon up through the dome and out the top.WCS has shown that Bio-Domes can treat pollutants quickly and effectively, reportedly operating at hundreds of dollars a month rather than the thousands of dollars for conventional treatment plants. And Bio-Domes can be retrofitted to existing lagoon systems, where they work in clusters, with two dozen or more arranged in rows fully submerged at the bottom of a wastewater lagoon. They can even be adapted to help clean up the waste from dairies and hog farms and industry.
Igloo-Shaped Devices Eat Sewage and Treat Wastewater
JANUARY 10, 2011
Wastewater Compliance Systems
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-Gloos" under the name Bio-Dome.
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.
How Much Poo Can a Poo-Gloo Remove?
Johnson spent time in the wastewater industry before obtaining his master's and doctoral degrees in civil and environmental engineering. In 2002, he set about developing a product that could be used to retrofit wastewater lagoons easily and inexpensively. After seven years, with the help of fellow professors, graduate students and a lot of laboratory tests, Johnson was ready for his first field test.
Johnson built a pilot unit using a large construction dumpster welded shut so it was water-tight. The container held seven Bio-Domes. Johnson enlisted the help of Salt Lake's Central Valley Water Reclamation Facility to test it. The researchers ran multiple tests using untreated wastewater from the plant to determine the extent to which commonly regulated pollutants could be removed from the wastewater before discharge back to the treatment facility.
The study aimed to determine optimal operating conditions for Bio-Domes and evaluate their performance at different water temperatures, levels of aeration, and sewage volumes and concentrations. The study found the devices consistently achieved high levels of treatment that were affected only slightly by changing water temperatures and aeration levels:
- Biological oxygen demand – a measure of organic waste in water – was reduced consistently by 85 percent using Bio-Domes, and by as much as 92 percent.
- Total suspended solids fell consistently by 85 percent, and by as much as 95 percent.
- Ammonia levels dropped more than 98 percent with Bio-Dome treatment in warmer water and, more important, by as much as 93 percent when temperatures dropped below 50 degrees Fahrenheit – conditions that normally slow bacterial breakdown of sewage.
- Total nitrogen levels fell 68 percent in warmer water and 55 percent in cooler water.
"The removal rates we saw during the pilot test are comparable to removal rates from a rotating biological contactor, which is a commonly used device in mechanical treatment facilities," Johnson says. "We couldn't be happier with the performance of the Poo-Gloos."
Johnson conducted the study with Hua Xu, a postdoctoral fellow in civil and environmental engineering at the University of Utah, and Youngik Choi, a professor of environmental engineering at Dong-A University in South Korea.
There may be uses for the Bio-Domes beyond municipal wastewater treatment.
"The bugs will adapt to consume whatever is available," says Johnson, "In addition to the pollutants discussed in our paper, we've also seen great results in the consumption of other significant pollutants that I can't discuss now because we're in the process of filing patents. Bio-Domes have a lot of potential, and we've only just scratched the surface."
Johnson and his team originally nicknamed the devices Poo-Gloos because they are shaped like igloos. But as possible uses began to expand to industries beyond municipal sewage treatment, Wastewater Compliance Systems decided to sell them as Bio-Domes.
From Nevada to Alabama and Wisconsin, Bio-Domes to the Rescue
"Every day I speak with community officials who need to upgrade their treatment facilities," says Taylor Reynolds, director of sales for Wastewater Compliance Systems. "They come to us because they receive an engineering report recommending a $4 million to $10 million mechanical plant project that is impossible for them to pay for with their existing tax base. Not only can our Poo-Gloos or Bio-Domes help communities comply with pollution limits, but most of the projects I quote cost between $150,000 and $500,000, and the operating expenses are a fraction those at a mechanical plant."
Each Bio-Dome requires little maintenance and the same amount of electricity as a 75-watt bulb, putting operating costs for Bio-Dome systems at hundreds of dollars per month rather than thousands, which is typical of mechanical treatment plants. And some communities may operate Bio-Domes "off-the-grid" by powering them with solar or wind energy systems.
The results of the new study prompted a number of communities to abandon more expensive alternatives in favor of installing Bio-Domes. These early adopters can be found in the Nevada town of Jackpot in Elko County, Glacier National Park in Montana, and Plain City and Wellsville in Utah. Wastewater Compliance Systems also has deployed mobile pilot Bio-Domes in Louisiana, Alabama and Wisconsin so potential customers, engineering firms and regulators can see first-hand how well they work before they commit tax dollars to the new technology.
"We know that small communities have limited budgets," Reynolds says. "That's why we developed our mobile pilot units. Even when our technology has the potential to save hundreds of thousands of dollars on an upgrade project, we like to provide our customers with peace of mind in knowing that our products will solve their problems for years to come. "
Technology: Enhanced Biological Wastewater Treatment
Without sufficient biological activity present to consume the dissolved compounds in a wastewater lagoon it is very easy for the discharged water to become non-compliant. WCS understands the importance of biological activity in reducing the levels of contaminants that can harm our waterways. While developing the bio-dome, WCS focused on creating optimal conditions to enhance and sustain robust biological activity,
In order to significantly enhance the biological activity in a wastewater lagoon, there are two core needs: aeration and lots of surface area for biofilm development. Our bio-domes simply and effectively introduce the needed air and the requisite surface area into existing water bodies without exorbitant capital costs. Additionally the unique design of the bio-domes results in a high Oxygen Transfer Efficiency (OTE) with a minimum of energy input. Our systems typically require one third the amount of energy as most aeration systems for the same performance.
As effluent requirements have become more stringent over the years, many communities have had to upgrade their facultative lagoons to aerated lagoons. The increased oxygen and to some extent the improved mixing has helped keep communities in compliance for many years. Unfortunately most aeration systems are incredibly inefficient and require large motors to be effective. This results in high utility bills and over the life of the system can increase the cost of the system by a factor of 5 - 10 times the original cost.. Because of its unique design and high OTE, each bio-dome requires 1 CFM of air at 5 psi under typical conditions and is able to achieve the same performance as typical aeration systems for a fraction of the cost. Bio-dome are also easy to install and maintain, making wastewater aeration simple to achieve and cost effective to maintain.
Biofilm is crucial in establishing robust biological activity in a wastewater lagoon. Suspended growth bacteria are not always able to develop in sufficient quantities in a typical wastewater lagoon, nor are they capable of surviving in cold weather environments. Biofilm allows a variety of beneficial bacteria to develop in higher concentrations than is possible in suspended growth. Biofilm growth is limited though by the amount of available surface area in the lagoon. To overcome this, the patented design of bio-domes creates an additional 2800 square feet of surface area inside each unit. This increase in surface area correlates directly to increased biological activity once the biofilm has had a chance to develop. The results of the increased biological activity speak for themselves!
Biological Wastewater Treatment
Coupling the increase in surface area with aeration and a dark environment that discourages algal competition has created the perfect environment for enhanced biological activity. The patented design of the bio-domes is a cost effective means of reducing unwanted contaminants in wastewater treatment systems. Not only are our systems effective at reducing BOD, Ammonia, and Total Nitrogen levels, but because the bacteria require a carbon source for food, we often see tremendous reductions in TSS levels as well.
Bio-Dome AKA Poo-Gloo Report to Utah (4,720 kb)
BioDome Product Specification Sheet (609 kb)
BioDome Info Sheet (271 kb)