CATEGORY: TVA Tennessee Valley Auth.
HED: TVA plumbs pig odor problem
By Marty Russell
STARKVILLE – A Tennessee Valley Authority chemical engineer says biofilter technology being tested in Choctaw County already removes 95 percent of hog odor compounds and could eliminate them all.
Laura Lackey presented preliminary findings to area hog farmers and TVA personnel this week. She manages the swine biofilter project for TVA’s Environmental Research Center in Muscle Shoals, Ala.
The study at a Calhoun County farm involves biofilters that use living microorganisms to literally eat the compounds that produce odors.
Hog farm odors are cited as the primary reason 33 counties in the state have opted to enact local restrictions on swine farms.
“The odor can be a great nuisance to neighbors and a great problem for farmers,” Lackey said. “It’s proven it can cause a variety of health problems from nausea on down the list.”
Two types of biofilters are being tested on an eight-barn swine operation in Choctaw County.
One uses natural materials much like compost that are conducive to microorganism growth. Another type, a biotrickling filter, uses nutrients suspended in liquid to feed the microorganisms that clean the air as it filters through.
Both methods are quick and effective, Lackey said.
“It actually only takes about 10 seconds,” she said. “(The odor) flies through the air and the bugs eat it.”
Tests show 95 percent of ammonia and amine compounds are removed in the process.
“We can do better,” said Lackey, who plans to present her findings to the state Department of Environmental Quality. “We’re just treating this as an experiment but we can design it for no emissions.”
Although the technology is cheap and easy to maintain – Lackey estimates the filter would only need to be replaced every five years – there are drawbacks to the system.
“The construction costs wouldn’t be that expensive,” Lackey said. “You just have to have the land.”
The research has shown that a biofilter capable of eliminating the odor from eight hog barns would cover about half an acre.
“It’s not for every farm but it certainly could be used on some farms.” Lackey said. “It’s cheaper than a lawyer.”