'Poo-Gloo' Devices Digest Sewage

/ Source: Discovery Channel

New igloo-shaped devices, affectionately known as Poo-Gloos, are offering an affordable way for small communities to upgrade their wastewater treatment systems.

Several towns nationwide have started using the domes lined with bacterial biofilm to clean water in existing facilities.

"The whole idea is to provide a home specifically designed for bacteria," said Kraig Johnson, chief technology officer for Wastewater Compliance Systems, the Salt Lake City, Utah-based startup that makes the devices.

Johnson began developing the technology in 2002, when he was a research assistant professor at the University of Utah. Each Poo-Gloo device is six feet in diameter, three feet high, and sits on a foot-tall base.

Seven plastic domes lined with biofilm are nested inside one to maximize surface area. Heterotrophic bacteria eat most of the carbon-based materials in raw sewage while autotrophic bacteria consume ammonia and nitrogen compounds.

The devices are placed in existing wastewater treatment lagoons that need to meet stricter environmental standards. Tubes within each device pump air bubbles through to support the autotrophs. This also circulates the sewage to feed the bacteria.

Building a new treatment plant would cost several million dollars while a Poo-Gloo installation runs between $100,000 and $200,000, Johnson said.

The devices also save energy. Ten of them require one horsepower. Recently, an eight-horsepower installation replaced a mechanical system that was using 40 to 60 horsepower and still couldn't meet stringent environmental requirements.

The company has sold about 200 devices so far and has put full-scale systems in Plain City and Wellsville, Utah, as well as Jackpot, Nevada, and Glacier National Park in Montana. "It's giving us points of separation as a legitimate solution," Johnson said.

This week Johnson is presenting results from a Poo-Gloo pilot project study at the Water Environment Federation's Impaired Water Symposium in Miami. Environmental engineers from University of Utah and Dong-A University in South Korea used a control tank to test the devices at a treatment facility in Salt Lake City. They found that turning the air off for a set amount of time maximized nitrogen and organic compound removal.

Tryg Lundquist, an assistant professor of environmental engineering at California Polytechnic State University, envisions a host of new affordable, sustainable, and effective wastewater treatment technologies emerging. He hopes Poo-Gloos will be one of them.

"They're trying to allow traditional wastewater lagoons to meet more strict effluent standards," he said. "That's an important thing to do because there are about 6,000 municipal wastewater treatment ponds in the U.S."

Tzahi Cath, an assistant professor of environmental science and engineering at the Colorado School of Mines noted the devices' limitations. "Phosphorus removal in wastewater treatment -- you can do it with biofilm, but [it's] not so effective," he said.

In addition to phosphorus, Johnson said the company is currently researching how Poo-Gloos could remove trickier chemicals like endocrine-disruptors.

"There's quite a long list of compounds that we'd like to get rid of in wastewater," he said. "We're working our way down."