Focus
on Research
Penn State Intercom......March
29, 2001
Constructed wetlands reduce
odors from swine manure wastewater
By John Wall
College of Agriculture
Sciences 
The feces, urine and wastewater that are byproducts of hog farms smell to high heaven. To reduce the odors, two researchers in the College of Agricultural Sciences have found that low-tech, constructed wetlands work well to clear the air.
Field trials in small-scale constructed wetlands in a greenhouse showed an 80 percent reduction in offensive odor compounds from unadulterated swine facility wastewater, said Eileen Wheeler, assistant professor of agricultural engineering. Wheeler and doctoral researcher Susan Wood sought to confirm anecdotal evidence that water treatment in a constructed wetland can reduce odors.
"Swine and other livestock producers inSouthern states have used constructed wetlands to treat animal waste, and researchers had noticed that smells were not as strong," Wheeler explained. "We wanted to see if we could quantify a reduction in odor in trials that would reflect real-world practices."
Wood constructed eight experimental wetlands in 100-gallon livestock tanks. She filled the tanks with gravel, added a layer of peat moss and planted a commercial wetlands seed mix containing a wide variety of plants, including fescue, redtop and wild rye. She also tested unplanted wetlands containing just gravel.
"Some of the grasses died where the water entered the wetlands," Wood said. "But in general, the planted wetlands effectively reduced odors."
Wood organized eight volunteers in a sensory odor panel that compared air samples from untreated swine wastewater and water that had been treated in the wetlands. The panel rated air samples on an odor scale of 0 to 5, with 5 being the most offensive. "Most of the untreated samples were rated as a 4, and the samples from wetland treatment had an average rating of 1," she explained. "The water that had been through the wetland had a stagnant, earthy smell, but it wasn't offensive."
Wheeler says Wood's research is focused on finding an alternative to other methods of treating swine waste for odor reduction. Current swine waste treatment practices include:
* Mechanical aeration of manure lagoons. Oxygen is bubbled into the wastewater, preventing anaerobic conditions that produce smells. "However, this technology has large power requirements that results in high energy costs," Wheeler said.
* Anaerobic digestion of wastes into biogas. This method requires expensive investment in equipment and high maintenance costs.
* Chemical or biological additives that counteract smells. Research has indicated that the effectiveness of most additives has been questionable.
The next step in Wheeler's research is to construct a large wetlands treatment facility on a local hog operation. If the larger wetland continues to effectively reduce odors, the researchers then will focus on whether it is economically feasible to use treatment wetlands on commercial farms.
The researchers also want to test how the wetlands function under different temperature conditions. "The constructed treatment wetlands that have been built in the South have warmer weather year-round," Wood explained. "We would like to see how these wetlands function during a Pennsylvania winter, or whether some kind of protective structure is required to keep them working."
Wheeler says swine operations can use the treated water as wash water for hosing out hog pens, or they may be able to store the water for use as fertilizer for crops.
"Treated wetlands are a low-tech solution to a major problem for modern hog farms," Wheeler said. "These wetlands have no pumps to fix, and aside from some pipes, very little equipment. It's like having a pet -- you have to feed it, but it can take care of itself most days."
Mad cow disease from tainted
beef is an
unlikely threat in America, researcher says
By Gary Abdullah
College of Agricultural
Science
Bovine spongiform encephalopathy (BSE), better known as "mad cow disease," is front-page news as European countries struggle to control the disease's spread in their cattle. But an expert in the College of Agricultural Sciences says American shoppers don't have to worry when buying beef.
"The worst may be over for the United States and Europe," said Lawrence Hutchinson, professor of veterinary science. "Corrective measures seem to be working. In North America, we've prohibited animal byproducts in feed and banned importing these for any use in this country. We think those two barriers prevented animals in the United States from being exposed to BSE.
"We also examine any animals that sicken or die of diseases of the brain or nervous system," he said. "In every case where the cause isn't known, samples of the animal are tested at the National Animal Disease Center in Iowa. To date, of more than 17,000 samples submitted, all have been negative."
Hutchinson says BSE in the United Kingdom has dropped from more than 24,000 cases in the peak year (1994) to about 1,300 cases last year, thanks to stringent quarantine and culling tactics, combined with the prohibition of all animal byproducts in cattle feed. Because the disease has an incubation period of two to eight years, the control measures should finally be taking hold.
"At this point, we feel very good about the fact that we're not finding any signs of disease, so meat products raised here in the United States are very safe from BSE," Hutchinson said.
Gary Abdullah can be reached at gxa2@psu.edu
Automation may be
worth investment
Information technology increases salesperson job performance through increases in market knowledge, technical knowledge, sales presentation skills, targeting abilities and call productivity, according to researchers in The Smeal College of Business Administration.
"The rapid growth and advances in computerized technologies in the last de-cade have significantly changed the everyday life of the modern sales representative," said Michael J. Ahearne, director of the Center for Sales and Customer Service, who conducted research to quantify the impact of automation/information technology use on salesforce performance. Initial research was conducted with a mid-sized pharmaceutical company.
"The research found that information technology usage did, in fact, increase salesperson market knowledge, technical knowledge, sales presentation skills, targeting abilities, and call productivity," he said.
Aphid-like insect
destroys hemlocks
Hemlock trees in the Northeast are declining and dying, and many experts are blaming an aphid-like insect known as the hemlock woolly adelgid. However, identifying a culprit is not that simple, according to a tree-pest specialist in the College of Agricultural Sciences.
"Hemlock woolly adelgid gets most of the publicity, but people shouldn't place all the blame for hemlock decline on this pest," says Gregory Hoover, extension entomologist. "Other insects are contributing, such as elongate hemlock scale, spruce spider mite, hemlock rust mite and cryptomeria scale."
Hemlock woolly adelgid is a serious threat. The tiny insect has piercing-sucking mouthparts that it uses to remove fluids from hemlock needles, causing them to dry out and drop prematurely. As trees thin and lose "leaf" area for photosynthesis, they become weak and more susceptible to drought stress and attack from other pests. Stressed trees eventually may die.
A free fact sheet on hemlock woolly adelgid can be obtained from any Cooperative Extension county office, or from http://www.ento.psu.edu/extension/factsheets/hemlockwoolly.htm.