By DOUG SCHMITZ
AMES, Iowa — Iowa State University researchers have discovered a unique way to use ultraviolet (UV) light to neutralize odors emanating from livestock facilities.
“We have shown that generic UV light works very well – up to a 100 percent reduction of these key gases,” said Jacek Koziel, ISU associate professor of agricultural and biosystems engineering.
Koziel and his team are using black light to help neutralize the volatile components that make up objectionable odors. Shined on surfaces coated with a thin layer of titanium dioxide, their research discovered the black light initiates photocatalytic reactions found to significantly reduce several odorous chemicals drifting downwind from livestock operations.
The June 10 issue of the journal Atmosphere describes the work in the lab that has led to a test in an Iowa swine facility. The paper, Mitigation of Livestock Odors Using Black Light and a New Titanium Dioxide-Based Catalyst: Proof-of-Concept online at www.mdpi.com/2073-4433/8/6/103 documents odor reductions from 40-100 percent.
Since joining the ISU agricultural and biosystems engineering faculty in 2004, Koziel has been studying livestock odor and air quality issues. About 10 years ago, he tested using UV light to break down compounds that are typically found in swine and poultry odors.
About two years ago, the Indiana Soybean Alliance funded a project to look at the use of black light, a milder version of UV light that is closer to visible light. Being less toxic, the black lights would mean fewer concerns about using it in the presence of the livestock and people working in the facilities.
According to Koziel and his team, a new type of the titanium dioxide (a powdery substance that is used as a whitener in a variety of products, including toothpaste) photocatalytic coating compensates for the lack of UV energy in the black lights. The coating is made by PURETi Group, LLC, which is the project’s industrial partner.
ISU researchers found the dust that’s prevalent in livestock facilities and accumulates on surfaces doesn’t affect its effectiveness in the lab.
“The pilot-scale research project, which was just finished, decreased odor emissions by 16 percent, while also reducing a key ‘signature’ gas responsible for the characteristic downwind odor emissions by 22 percent,” Koziel explained. “An unexpected result was a 9 percent reduction in nitrous oxide, a major greenhouse gas.”
For the next stage of research, Koziel said the black light will be directed on the ceilings and upper portions of walls, coated with titanium dioxide, inside livestock buildings. He added a similar setup was tested by a research group in Italy, and that small-scale study, which used regular UV light, showed the pigs had greater feed efficiency.
“If that holds true and can be replicated, that’s an awesome potential finding for the swine industry,” he noted.
Ron Birkenholz, Iowa Pork Producers Assoc. director of communications, said if researchers can actually find a way to reduce odors from hog barns using black lights and a catalyst, they have the industry’s attention.
“If a product actually makes it to the marketplace, and is proven to be efficient and effective without being cost-prohibitive,” he said, “I think the industry will embrace it. The industry is continually looking for ways to improve, be more efficient and productive, and be better neighbors. This could potentially make pig farmers more neighborly.”
Koziel is hopeful the tests conducted in an actual swine facility in northeastern Iowa will continue to be promising. “It is necessary to study the system outside the lab because conditions, such as air movement, are highly variable in livestock facilities.”