Odor and Odorous Chemical Emissions from Animal Buildings: Part 2. Odor Emissions

This study was an add-on project to the National Air Emissions Monitoring Study (NAEMS) and focused on comprehensive measurement of odor emissions considering variations in seasons, animal types, and olfactometry laboratories. Odor emissions from four of 14 NAEMS sites with nine barns/rooms (two dairy barns at the WI5B and IN5B sites, two pig finishing rooms at IN3B, and two sow gestation barns and a farrowing room at the IA4B site) were measured during four 13-week cycles. Odor emissions were reported per barn area (OU h-1 m-2), head (OU h-1 head-1), and animal unit (OU h-1 AU-1). The highest overall odor emission rates were measured in summer (1.2 × 105 OU h-1 m-2, 3.5 × 105 OU h-1 head-1, and 6.2 × 105 OU h-1 AU-1), and the lowest rates were measured in winter (2.5 × 104 OU h-1 m-2, 9.1 × 104 OU h-1 head-1, and 1.5 × 105 OU h-1 AU-1). The highest ambient odor concentrations and barn odor emissions were measured from the sow gestation barns of the IA4B site, which had unusually high H2S concentrations. The most intense odor and the least pleasant odor were also measured at this site. The overall odor emission rates of the pig finishing rooms at IN3B were lower than the emission rates of the IA4B sow gestation barns. The lowest overall barn odor emission rates were measured at the IN5B dairy barns. However, the lowest ambient odor concentrations were measured at the ventilation inlets of the WI5B dairy barns

Air Pollutant Emissions from Confined Animal Buildings (APECAB) Project: Minnesota Data

To address the need for gas, odor, and particulate matter (PM) emission from animal production buildings, funding was secured in the fall of 2001 by a six-state research team for a USDA project entitled Air Pollutants Emissions from Confined Animal Buildings, or APECAB. The main objective of the APECAB project was to quantify long-term (yearly) air pollutant emissions from confined animal buildings and establish methodologies for real time measurement of these emissions and build a database of air emissions for US livestock and poultry buildings. The APECAB study was a collaboration of land-grant universities in Minnesota (lead institution), Indiana, Illinois, Texas, Iowa, and North Carolina. Extensive planning occurred during the first nine months for protocol development and equipment selection and purchase. Data collection began at various times during the fall of 2002 for each of the cooperating universities and ended at various times in 2004. The immediate goal of the study was a 15-month sampling period to assure that long-term emissions from actual animal production buildings were determined. Long-term measurements revealed the variations in air emissions due to seasonal effects, animal growth cycles, diurnal variations, and manure handling systems

Air Pollutant Emissions from Confined Animal Buildings (APECAB) Project: Indiana Data

To address the need for gas, odor, and particulate matter (PM) emission from animal production buildings, funding was secured in the fall of 2001 by a six-state research team for a USDA project entitled Air Pollutants Emissions from Confined Animal Buildings, or APECAB. The main objective of the APECAB project was to quantify long-term (yearly) air pollutant emissions from confined animal buildings and establish methodologies for real time measurement of these emissions and build a database of air emissions for US livestock and poultry buildings. The APECAB study was a collaboration of land-grant universities in Minnesota (lead institution), Indiana, Illinois, Texas, Iowa, and North Carolina. Extensive planning occurred during the first nine months for protocol development and equipment selection and purchase. Data collection began at various times during the fall of 2002 for each of the cooperating universities and ended at various times in 2004. The immediate goal of the study was a 15-month sampling period to assure that long-term emissions from actual animal production buildings were determined. Long-term measurements revealed the variations in air emissions due to seasonal effects, animal growth cycles, diurnal variations, and manure handling systems

Air Pollutant Emissions from Confined Animal Buildings (APECAB) Project: Iowa Data

To address the need for gas, odor, and particulate matter (PM) emission from animal production buildings, funding was secured in the fall of 2001 by a six-state research team for a USDA project entitled Air Pollutants Emissions from Confined Animal Buildings, or APECAB. The main objective of the APECAB project was to quantify long-term (yearly) air pollutant emissions from confined animal buildings and establish methodologies for real time measurement of these emissions and build a database of air emissions for US livestock and poultry buildings. The APECAB study was a collaboration of land-grant universities in Minnesota (lead institution), Indiana, Illinois, Texas, Iowa, and North Carolina. Extensive planning occurred during the first nine months for protocol development and equipment selection and purchase. Data collection began at various times during the fall of 2002 for each of the cooperating universities and ended at various times in 2004. The immediate goal of the study was a 15-month sampling period to assure that long-term emissions from actual animal production buildings were determined. Long-term measurements revealed the variations in air emissions due to seasonal effects, animal growth cycles, diurnal variations, and manure handling systems

Odor and Odorous Chemical Emissions from Animal Buildings: Part 5—Correlations between Odor Intensities and Chemical Concentrations (gc-ms/o)

Simultaneous chemical and sensory analysis based on gas chromatography-mass spectrometry-olfactometry (GC-MS-O) of air samples from livestock operations is a very useful approach for quantification of target odorous gases and also for ranking of odorous compounds. This information can help link specific gases to odor, that can assist in solving farm odor problems and in evaluating of odor mitigation technologies. In this study, we applied the fundamental Weber-Fechner law to correlate the odor intensity and odorous chemical concentration for 15 individual target compounds (from GC-MS-O) for the gas samples collected from four livestock facilities (dairy barns in Wisconsin and Indiana and swine barns in Iowa and Indiana) over a one year period. The results showed that most of the correlations between odor intensities and chemical concentrations for the 15 odorous VOCs sampled fit well with the Weber-Fechner law and had correlation coefficient (R2) greater than 0.65, with R2s of 0.84, 0.83, and 0.82 for 4-methylphenol, 3-methylbutanoic acid, and 3-methylindole, respectively. The odorous compounds with higher mean odor activity value (OAV) values fit better with the Weber-Fechner law whereas the odorous compounds with lower mean OAV values resulted in relatively poor R2 values to the relatively large variations for odor intensities obtained from GC-MS/O for these compounds with low concentrations. The correlations for odorous compounds between odor intensities and chemical concentrations for swine sites were much better than that for dairy sites. R2s for eight out of fifteen compounds for the two swine sites were greater than 0.60 whereas only one R2 (butyric acid) was greater than 0.60 for two dairy sites

Quality Assured Measurements of Animal Building Emissions: Odor Concentrations

Standard protocols for sampling and measuring odor emissions from livestock buildings are needed to guide scientists, consultants, regulators, and policy-makers. A federally funded, multistate project has conducted field studies in six states to measure emissions of odor, coarse particulate matter (PM10), total suspended particulates, hydrogen sulfide, ammonia, and carbon dioxide from swine and poultry production buildings. The focus of this paper is on the intermittent measurement of odor concentrations at nearly identical pairs of buildings in each state and on protocols to minimize variations in these measurements. Air was collected from pig and poultry barns in small (10 L) Tedlar bags through a gas sampling system located in an instrument trailer housing gas and dust analyzers. The samples were analyzed within 30 hr by a dynamic dilution forced-choice olfactometer (a dilution apparatus). The olfactometers (AC’SCENT International Olfactometer, St. Croix Sensory, Inc.) used by all participating laboratories meet the olfactometry standards (American Society for Testing and Materials and European Committee for Standardization [CEN]) in the United States and Europe. Trained panelists (four to eight) at each laboratory measured odor concentrations (dilution to thresholds [DT]) from the bag samples. Odor emissions were calculated by multiplying odor concentration differences between inlet and outlet air by standardized (20 °C and 1 atm) building airflow rates

Odor and Odorous Chemical Emissions from Animal Buildings: Part 6. Odor Activity Value

There is a growing concern with air and odor emissions from agricultural facilities. A supplementary research project was conducted to complement the U.S. National Air Emissions Monitoring Study (NAEMS). The overall goal of the project was to establish odor and chemical emission factors for animal feeding operations. The study was conducted over a 17-month period at two freestall dairies, one swine sow farm, and one swine finisher facility. Samples from a representative exhaust airstream at each barn were collected in 10 L Tedlar bags and analyzed by trained human panelists using dynamic triangular forced-choice olfactometry. Samples were simultaneously analyzed for 20 odorous compounds (acetic acid, propanoic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, hexanoic acid, heptanoic acid, guaiacol, phenol, 4-methylphenol, 4-ethylphenol, 2-aminoacetophenone, indole, skatole, dimethyl disulfide, diethyl disulfide, dimethyl trisulfide, hydrogen sulfide, and ammonia). In this article, which is part 6 of a six-part series summarizing results of the project, we investigate the correlations between odor concentrations and odor activity value (OAV), defined as the concentration of a single compound divided by the odor threshold for that compound. The specific objectives were to determine which compounds contributed most to the overall odor emanating from swine and dairy buildings, and develop equations for predicting odor concentration based on compound OAVs. Single-compound odor thresholds (SCOT) were statistically summarized and analyzed, and OAVs were calculated for all compounds. Odor concentrations were regressed against OAV values using multivariate regression techniques. Both swine sites had four common compounds with the highest OAVs (ranked high to low: hydrogen sulfide, 4-methylphenol, butyric acid, isovaleric acid). The dairy sites had these same four compounds in common in the top five, and in addition diethyl disulfide was ranked second at one dairy site, while ammonia was ranked third at the other dairy site. Summed OAVs were not a good predictor of odor concentration (R2 = 0.16 to 0.52), underestimating actual odor concentrations by 2 to 3 times. Based on the OAV and regression analyses, we conclude that hydrogen sulfide, 4-methylphenol, isovaleric acid, ammonia, and diethyl disulfide are the most likely contributors to swine odor, while hydrogen sulfide, 4-methyl phenol, butyric acid, and isovaleric acid are the most likely contributors to dairy odors

Odor and Odorous Chemical Emissions from Animal Buildings: Part 4—Correlations Between Sensory and Chemical Measurements

This study supplemented the National Air Emissions Monitoring Study (NAEMS) by making comprehensive measurements, over a full calendar year, of odor emissions from five swine and four dairy rooms/buildings (subset of the total number of buildings monitored for the NAEMS project). The measurements made in this project included both standard human sensory measurements using dynamic forced-choice olfactometer and a novel chemical analysis technique for odorous compounds found in these emissions. Odor and hydrogen sulfide (H2S) and ammonia (NH3) concentrations for all dairy and swine buildings had a statistically significant correlation. A higher number of correlations between odor and volatile organic compounds (VOCs) were found for the five swine rooms/buildings (two rooms in a pig finishing barn, two sow gestation barns, and a farrowing room) compared to the four dairy buildings. Phenol and 4-methyl phenol (p-cresol) concentrations were well correlated (R2\u3e50%) with odor concentrations in the five swine rooms/buildings but not significantly correlated in the four dairy buildings