Emissions of volatile organic compounds (VOCs) from concentrated animal feeding operations (CAFOs): chemical compositions and separation of sources

Abstract

<p><strong>Abstract.</strong> Concentrated animal feeding operations (CAFOs) emit a large number of volatile organic compounds (VOCs) to the atmosphere. In this study, we conducted mobile laboratory measurements of VOCs, methane (CH<sub>4</sub>) and ammonia (NH<sub>3</sub>) downwind of dairy cattle, beef cattle, sheep and chicken CAFO facilities in northeastern Colorado using a hydronium ion time-of-flight chemical-ionization mass spectrometer (H<sub>3</sub>O<sup>+</sup> ToF-CIMS) that can detect numerous VOCs. Regional measurements of CAFO emissions in northeastern Colorado were also performed using the NOAA WP-3D aircraft during the Shale Oil and Natural Gas Nexus (SONGNEX) campaign. Alcohols and carboxylic acids dominate VOC concentrations and the reactivity of the VOCs with hydroxyl (OH) radicals. Sulfur-containing and phenolic species provide the largest contributions to in the odor activity values and the nitrate radical (NO<sub>3</sub>) reactivity of VOC emissions, respectively. VOC compositions determined from mobile laboratory and aircraft measurements generally agree well with each other. The high time-resolution mobile measurements allow the separation of the sources of VOCs from different parts of the operations occurring within the facilities. We show that the emissions of ethanol concentrations are primarily associated with feed storage and handling. Based on mobile laboratory measurements, we apply a multivariate regression analysis using NH<sub>3</sub> and ethanol as tracers to determine the relative importance of animal-related emissions (animal exhalation and waste) and feed-related emissions (feed storage and handling) for different VOC species. Feed storage and handling contribute significantly to emissions of alcohols, carbonyls, carboxylic acids and sulfur-containing species. Emissions of phenolic species and nitrogen-containing species are predominantly associated with animals and their waste.</p>

The Effect of Dairy Cattle Housing Systems on the Concentrations and Emissions of Gaseous Mixtures in Barns Determined by Fourier-Transform Infrared Spectroscopy

“…Barn FS-LS was also characterized by a high concentration of chloromethane. In the literature, high levels of alcohol (ethanol and methanol) and acetic acid were also identified in barns in addition to methane (Gentner et al, 2014;Yuan et al, 2017). In the present study, the above compounds were not detected in air, but the presence of related compounds was confirmed.…”

“…The conducted measurements suggest that VOC emissions in dairy farms can be even ten times lower than the estimated values (Shaw et al, 2007). A limited number of studies indicate that in addition to CH4 (saturated carbohydrate), dairy cattle farms are also a source of organic compounds such as alcohols, carboxylic acids, ketones, aldehydes, esters, ethers, aromatic and halogen hydrocarbons, terpenes, amines, other organosulfur and nitrogen compounds, and phenols (Filipy et al, 2006;Shaw et al, 2007;Gentner et al, 2014;Yuan et al, 2017). A total of 32 VOCs were identified in our study (20 VOCs were present in each barn), and most of them belonged to the chemical groups identified in the cited research, including saturated, unsaturated, aromatic and halogenated hydrocarbons, alcohols, ethers, thiols, aldehydes, ketones, amines, azines, sulfides and nitriles (Figure 8).…”

“…Sulfur dioxide levels were higher (up to 1.5 ppm) in the barn where manure was stored under the floor and lower in barns with deep litter. This compound is produced during protein transformation processes, and it is characterized by an irritating odor with a low odor threshold (Yuan et al, 2017). Sulfur dioxide concentration was higher in barns where manure was less frequently removed.…”

“…Mass spectrometry and gas chromatography analyses have revealed that in addition to methane (saturated carbohydrate), dairy and beef cattle farms are also a source of organic compounds such as alcohols, carboxylic acids, ketones, aldehydes, esters, ethers, aromatic and halogen hydrocarbons, terpenes, amines, other organosulfur and nitrogen compounds (Cai et al, 2006;Filipy et al, 2006;Shaw et al, 2007;Laor et al, 2008;Gentner et al, 2014;Yuan et al, 2017), and, possibly, phenols (Shaw et al, 2007). Filipy et al (2006) have identified 113 VOCs in a barn, including 82 VOCs in the stalls of lactating cows, and 73 VOCs in slurry pits.…”

Measurement of formic acid, acetic acid and hydroxyacetaldehyde, hydrogen peroxide, and methyl peroxide in air by chemical ionization mass spectrometry: airborne method development

“…This could be secondary production from an upslope flow event and subsequent spillover event (Pfister et al, 2017). There was high AAES (up to 14 ppb) below 0.5 km (a.g.l., above ground level) corresponding to high NH 3 (Aerodyne Research, Inc., Herndon et al, 2005) with a maximum mixing ratio of 180 ppb near Greeley, which is an area associated with a concentration of confined animal feedlot operations (Eilerman et al, 2016;Yuan et al, 2017). If the signal at m/z 187 were primarily HAc, the HAc : NH 3 ratio was 0.078 ppb ppb −1 , which is within the range reported by Paulot et al (2011) though larger than the enhancement ratio range of 0.02-0.04 ppb ppb −1 reported by Yuan et al (2017).…”