Bioreactor Keeps Whitewater in Business

A southwestern Ohio turkey processing plant has much to be thankful for this season.

Published on: Nov 25, 2012

Whitewater Processing Co. slaughters and processes 6,000 to 8,000 turkeys on a normal day, producing about 2.5 to 3 million pounds of turkey in an average month. The Kopp family has run the business since the 1930s, and with 110 employees, wanted to stay put.

But in the 1990s, environmental concerns about the 145,000 gallons of wastewater it produces each day nearly sunk the business.

Today, with a first-of-its-kind treatment system designed by an Ohio State University researcher, the rough waters have calmed.

And though the costs have been considerable -- about $1 million to build the wastewater treatment system plus an estimated $1.8 million to operate and maintain it over the next 20 years -- the Kopp family figures the business will save at least $10 million over the next-best alternative.

Workers spread fine sand in a bioreactor cell at Whitewater Processing, Inc. The sand is the heart of the wastewater treatment system: Microbes populate the surface of the sand grains to break down and remove pollutants from the water. (Photo courtesy of Ryan Kopp)
Workers spread fine sand in a bioreactor cell at Whitewater Processing, Inc. The sand is the heart of the wastewater treatment system: Microbes populate the surface of the sand grains to break down and remove pollutants from the water. (Photo courtesy of Ryan Kopp)

"It's working very well, we're very excited about it," says Ryan Kopp, project manager.

In the late 1990s, Whitewater began working with Karen Mancl, an environmental scientist and Ohio State University Extension water quality specialist, after the Ohio Environmental Protection Agency grew concerned about the company's open-lagoon wastewater treatment system, especially with the Whitewater River so close to the facility.

"It's a beautiful river, and we definitely wanted to make sure it's protected," says Mancl.

The timing was fortuitous: Mancl had just finished a study on using a sand bioreactor system to treat wastewater from a cheese-making plant. Though that company didn't follow through with the system, Mancl's studies showed bioreactors provide an effective way to treat high-fat, high-organic-matter wastewater at a relatively low cost.

Whitewater's options were limited. The EPA first suggested it hook up to Harrison's municipal wastewater treatment plant. But the company would still need to pretreat its water to remove pollutants that the municipal system wasn't designed to handle, and it would still have to pay a premium to the facility.

The total cost for the construction of the pretreatment facility, hook-up and use of the Harrison treatment plant over 20 years was estimated at $12.5 million.

"And it likely would have been even more," Kopp says. "They had given us some estimates for future increases in treatment costs when we first looked at that option, and so far the actual increases have been more than they projected."

In 2001, Whitewater began funding research in Mancl's lab to determine if bioreactors would work for the type of wastewater its facility generated. That funding continued year after year as Mancl, graduate students and post-doctoral researchers ran test after test in the lab.

"With all of Karen's work, we knew the system would work great," Kopp says. "It was just a matter of scaling up to what we needed for commercial use."

A bioreactor system works like this: First, the wastewater is screened to remove as much of the suspended solids as possible before it is flowed through beds of sand and gravel. Microbes quickly populate the surface of the sand grains and gravel pieces, and they feast on the organic matter, breaking it down and removing it from the water. Treated water runs clear.

In fact, before treatment, the effluent at Whitewater is measured at over 800 BOD (biological oxygen demand), the standard that regulators use to measure water pollution. Normal sewage has a BOD of about 200.

When Whitewater's wastewater is tested after treatment, its BOD is less than 5, and it can be released directly into the Whitewater River, with the Ohio EPA's blessing.

"The EPA has been very helpful through this whole process," Kopp says. "Very patient."

Whitewater's bioreactor system covers 4 acres of land adjacent to the facility.~~~PAGE_BREAK_HERE~~~

"If you visit, it looks sort of like a park," Mancl says. "All you see are 12 large rectangles of gravel, and grass is all around them.

"Under the gravel are the pipes that carry the wastewater and spray it, underground, onto the sand. It's quiet, there's no odor, and even though most wastewater treatment plants aren't necessarily something you want to look at, it's not ugly. They plan to plant trees to make it even more attractive."

One of the challenges with the system is that operators must be sure the bioreactor doesn't get overwhelmed and become clogged, she says.

"If the sand was to get clogged, the research we conducted here at Ohio State shows you need to turn that filter off and let it rest, and send the wastewater to another cell," Mancl  says. "Then the microbes consume the wastes that have clogged the filter and unclog it. That takes about four months."

Mancl knows this because her lab tested it.

"The typical loading rate for a bioreactor system is about 1.5 gallons per square foot per day," she said. "We loaded our lab system up with 6 gallons per square foot per day, and it took a year to clog the sand.

"Then we let it rest, and after four months, it worked just like a brand new filter. You just have to let the microbes work to consume the extra organic matter that clogged the sand."

The amount of wastewater generated at Whitewater requires the use of eight bioreactor cells at a time. Whitewater is building 12 cells to have the backups needed to let filters rest; eight cells are currently online and in operation.

"Two additional cells are 80% percent complete, with two more to go," Kopp says.

Anyone interested in learning more and getting a closeup look at Whitewater's facility can sign up for a Cincinnati-area conference Mancl is organizing on April 11-12, 2013.

"Low-cost Treatment of Meat Processing Wastewater" is the topic of her annual 2013 Water Quality and Waste Management Conference. Registration is $200 before April 1. Details and online registration are available at http://setll.osu.edu/programs/owqwm_conf.html.

Source: OSU College of Food, Agricultural, and Environmental Sciences