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United States Department of Agriculture

Agricultural Research Service

Research Project: Management of Manure Nutrients, Environmental Contaminants, and Energy From Cattle and Swine Production Facilities

Location: Nutrition and Environmental Management Research

Title: Vegetative environmental buffers and exhaust fan deflectors for reducing downwind odor and VOCs from tunnel-ventilated swine barns

Authors
item Parker, David
item Malone, G
item Walter, W

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 5, 2011
Publication Date: March 8, 2012
Citation: Parker, D.B., Malone, G.W., Walter, W.D. 2012. Vegetative environmental buffers and exhaust fan deflectors for reducing downwind odor and VOCs from tunnel-ventilated swine barns. Transactions of the ASABE. 55(1):227-240.

Interpretive Summary: Shelterbelts and windbreaks, which are vegetation systems arranged in rows or groups, have been used for years to reduce wind effects around houses and outdoor animals. Recently, specially designed combinations of trees, shrubs and grasses have been planted outside of large animal feeding buildings with the purpose of reducing downwind air quality impacts. These specially designed systems are called Vegetative Environmental Buffers (VEB). We conducted a field research project at two similar 8-barn swine finisher sites to assess the effectiveness of VEBs for reducing downwind odor impacts from tunnel-ventilated swine barns. One site was equipped with a VEB and the other site served as the control. The barns at the VEB site were equipped with fan plume deflectors that guided the fan airflow down into the base of the VEB. Odor was monitored for six months with trained human panelists at eight locations, upwind and downwind of the VEB, barns, and lagoons. The chemical compounds responsible for odor, called volatile organic compounds (VOC) were also quantified. As compared to the control site, the VEB reduced odor concentrations by 49.1% in the VEB and 66.3% at distance 15 m downwind of the VEB. In a laboratory experiment, we also compared VOC emissions from VEB vegetation samples collected at the site. Emission rates from vegetation were 78 to 98% lower after rinsing to remove the dust, qualitatively showing that dust captured on the vegetation reduces odor emissions. The results of these field and laboratory experiments confirm that VEBs reduce downwind odor by increasing dilution and capturing odorous dust in the vegetation.

Technical Abstract: Scientists have investigated methods for reducing odor emissions from livestock buildings for decades, yet few technologies have proven effective. Vegetative Environmental Buffers (VEB), which are specially designed combinations of trees, shrubs and grasses, have shown promise in recent years for reducing odors at poultry operations, but have seen less testing at swine farms. A field research project was conducted at two similar 8-barn swine finisher sites in Missouri to assess the effectiveness of VEBs for reducing downwind odor impacts from tunnel-ventilated swine barns. A VEB with fan plume deflectors was installed in spring 2009 at one 8-barn site, and the other site served as the control. Odor was monitored from July-Nov 2009, with trained human panelists at eight locations, upwind and downwind of the VEB, barns, and lagoons. Five aromatic Volatile Organic Compounds (VOCs: phenol, 4-methylphenol, 4-ethylphenol, indole, skatole) were sampled from ambient air using sorbent tubes and GC/MS. As compared to the control site, the VEB reduced odor concentrations (D/T) by 49.1% in the VEB and 66.3% at distance 15 m downwind of the VEB (p<0.001). There was a larger percentage of non-detect odor concentrations (D/T<2) at 15 m downwind for the VEB site (57.6%) as compared to the control site (16.4%). Mean upwind odor concentrations ranged from 1.4 to 2.4 D/T. Mean odor concentrations at the 300 m downwind location were 2.3 and 2.5 D/T for the control and VEB site (p=0.47). In Nov 2010, a laboratory wind tunnel was used to compare VOC flux from VEB vegetation samples before and after rinsing. Wind tunnel VOC fluxes from vegetation were 78 to 98% lower after rinsing, qualitatively showing that particulate matter (PM) captured on the vegetation reduces odor emissions. The results of these field and laboratory experiments confirm that VEBs reduce downwind odor by increasing dilution and capturing odorous PM in the vegetation.

Last Modified: 12/19/2014