Using Olfactometry to Measure Intensity and Threshold Dilution Ratio for Evaluating Swine Odor

North Carolina Department of Environment and Natural Resources, Division of Air Quality, Fayetteville, USA.
Journal of the Air & Waste Management Association (1995) (Impact Factor: 1.34). 08/1999; 49(7):847-53. DOI: 10.1080/10473289.1999.10463855
Source: PubMed


Intensity and threshold dilution ratio are two important indices for odor control of swine buildings. Although odor threshold dilution ratio is a widely used index to describe an odor, it should be related to intensity to be more useful. A method was proposed to measure both indices simultaneously by using a dynamic forced-choice olfactometer. Four air samples were taken from each of four swine rooms including farrowing, finisher, gestation, and nursery. A panel of eight people was used to evaluate odor intensity. Odor threshold dilution ratios were calculated according to the American Society for Testing and Materials (ASTM) Standard Practice E679-91 to be 333, 424, 25, and 221 for samples collected from farrowing, finisher, gestation, and nursery rooms, respectively. After the samples were diluted 14.7 times, the odor intensities were evaluated to be 3.79, 3.46, 0.48, and 4.0 for the above-mentioned rooms, respectively. The data collected were used to develop a mathematical model.

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    • "1352-2310/$ e see front matter Published by Elsevier Ltd. Atmospheric Environment 60 (2012) 292e297 PURCHASED BY THE UNITED STATES DEPARTMENT OF AGRICULTURE FOR OFFICIAL USE agriculture (Chen et al., 1999 "
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    ABSTRACT: Odor and volatile organic compound (VOC) emissions are a concern at animal feeding operations (AFOs). The issue has become more prevalent as human residences move into areas once occupied only by agriculture. Odors near AFOs are generally caused by odorous VOCs emitted from manure, the mixture of feces and urine. Wet distillers grains with solubles (WDGS) are a by-product of the ethanol industry, and WDGS have become a staple in many beef cattle finishing diets. The objective of this research was to determine specific VOC emissions from frozen feces and urine of cattle fed steam-flaked corn (SFC)-based diets containing 0, 15, 30, or 45% WDGS. No differences in flux were detected across dietary treatments for phenol, indole, skatole, or 4-methylphenol (P > 0.23). Dimethyl disulfide and dimethyl trisulfide flux in feces were not different across treatments (P > 0.35) and the flux of volatile fatty acids (VFA) such as acetic, propionic, isobutyric, butyric, isovaleric, and valeric were not different across treatments (P > 0.25). There was a tendency for dimethyl disulfide flux from urine to be greater for cattle consuming an SFC-based diet with 15% WDGS than the other diets (P = 0.10). Furthermore, flux of acetic, propionic, isobutyric, butyric, and isovaleric acid from the urine were not different (P > 0.61) across dietary treatment. There were no significant differences in odor activity value (OAV) across treatments for feces, and only a tendency for dimethyl disulfide in the feces (P = 0.09). Thus, there was no obvious indication that feeding WDGS in conjunction with SFC affects flux of odor or odorous VOC from beef manure. The summed OAV was three times higher in the urine than feces, and a single odorous compound (4-methylphenol) accounted for 97.6%and 67.3% of the OAV in urine and feces, respectively. Therefore, engineering or dietary strategies to reduce odor from beef cattle manure should focus on controlling or reducing 4-methylphenol concentrations in the urine and feces.
    Atmospheric Environment 12/2012; 60:292–297. DOI:10.1016/j.atmosenv.2012.06.080 · 3.28 Impact Factor
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    • "Volatile organic compound emissions are an important aspect of air quality because many are malodorous. There has been a growing concern in recent years over VOC emissions and the related nuisances from agricultural operations, prompting several states to enact ambient odor regulations (Sweeten, 1995; Chen et al., 1999; CAQCC, 1999; Redwine and Lacey, 2000). More than 200 VOC have been identified in air emissions from manure and animal feeding operations (Kai and Schafer, 2004; Akdeniz et al., 2010). "
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    ABSTRACT: The objective of the research was to determine the optimum application rates of soybean peroxidase (SBP) plus peroxide (SBPP) for reducing odorous VOC emissions from swine manure. Industrial-grade SBP was applied in combination with liquid hydrogen peroxide (H(2)O(2)) or powdered calcium peroxide (CaO(2)) to standard phenolic solutions and swine manure, and emissions were measured in a wind tunnel. The primary odorant in the untreated manure was 4-methylphenol, which accounted for 68-81% of the odor activity value. At the optimum application rate of SBPP (50gL(-1)), 4-methylphenol emissions were reduced from the swine manure by 62% (H(2)O(2)) and 98% (CaO(2)) after 24h (P<0.0001). The CaO(2) had a longer residence time, remaining effective for 48h with 92% reduction in emission rates (P<0.0001), while H(2)O(2) was similar to the control at 48h (P=0.28).
    Bioresource Technology 11/2012; 124:95-104. DOI:10.1016/j.biortech.2012.08.031 · 4.49 Impact Factor
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    • "Olfactometry is a standard method for assessing odors at concentrated animal feeding operations (CAFOs) (Chen et al., 1997; Clanton et al., 1999; Dravnieks et al., 1978). Odor samples are collected in 'plastic' bags constructed of Teflon®, Tedlar®, or polyethylene. "
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    ABSTRACT: Tedlar® film is manufactured in a wet solvent process and continues to emit organic compounds after manufacturing. Tedlar® bags are used for odor sampling at concentrated animal feeding operations (CAFOs). Odor regulations for CAFOs vary widely, but maximum detection thresholds (DT) of 2 to 15 have been proposed downwind of feeding operations. Results at the WTAMU Olfactometry Laboratory have shown that both commercially available Tedlar® bags and homemade Tedlar® bags have a detectable background odor (DTs of 20 to 60 typical) even following standard protocols for purging. Purging the bags before sampling was not effective in reducing DTs to acceptable levels, as verified with SPME analysis. Heating the Tedlar® bags for 24 hrs, when combined with purging immediately after heating and again prior to odor sampling, reduced background DTs to less than 12. This is an acceptable range for odor sampling at open lot beef cattle feedyards or any other locations where DTs are expected to be greater than sixteen.
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