@article{james_blunden_rumsey_aneja_2012, title={Characterizing ammonia emissions from a commercial mechanically ventilated swine finishing facility and an anaerobic waste lagoon in North Carolina}, volume={3}, ISSN={["1309-1042"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84881622224&partnerID=MN8TOARS}, DOI={10.5094/apr.2012.031}, abstractNote={Abstract Emissions of atmospheric ammonia–nitrogen [NH 3 –N, where NH 3 –N = (14/17) NH 3 ] were measured from a commercial anaerobic swine waste treatment lagoon and from an on–site finishing swine confinement house at the same location. Continuous measurements were made at each potential NH 3 –N source for ~1 week during four different seasons. Results presented here represent measurements made for the second year of a multi–year experiment. Barn emissions were estimated to be 2 604 ± 660 g NH 3 –N day −1 , 1 761 ± 1 087 g NH 3 –N day −1 , 1 657 ± 1 506 g NH 3 –N day −1 , and 2 659 ± 1 194 g NH 3 –N g day −1 in summer, fall, winter, and spring respectively. NH 3 –N barn emission factors were calculated to be 1.32 ± 0.32 kg NH 3 –N animal −1 yr −1 , 0.78 ± 0.49 kg NH 3 –N animal −1 yr −1 , 1.55 ± 1.40 kg NH 3 –N animal −1 yr −1 , and 1.35 ± 0.61 kg NH 3 –N animal −1 yr −1 in summer, fall, winter, and spring respectively. Average NH 3 –N flux from lagoon was greatest in the summer, >3 943 μg m −2 min −1 , and lowest in the winter, 981 ± 210 μg m −2 min −1 . Fall and spring average NH 3 –N flux values were >1 383 μg m −2 min −1 and 1 641 ± 362 μg m −2 min −1 , respectively.}, number={3}, journal={ATMOSPHERIC POLLUTION RESEARCH}, author={James, Kristen M. and Blunden, Jessica and Rumsey, Ian C. and Aneja, Viney P.}, year={2012}, month={Jul}, pages={279–288} }
 @article{aneja_blunden_james_schlesinger_knighton_gilliam_jennings_niyogi_cole_2008, title={Ammonia assessment from agriculture: US status and needs}, volume={37}, ISSN={["1537-2537"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-40849136515&partnerID=MN8TOARS}, DOI={10.2134/jeq2007.0002in}, abstractNote={AbstractRecent studies suggest that human activities accelerate the production of reactive nitrogen on a global scale. Increased nitrogen emissions may lead to environmental impacts including photochemical air pollution, reduced visibility, changes in biodiversity, and stratospheric ozone depletion. In the last 50 yr, emissions of ammonia (NH3), which is the most abundant form of reduced reactive nitrogen in the atmosphere, have significantly increased as a result of intensive agricultural management and greater livestock production in many developed countries. These agricultural production practices are increasingly subject to governmental regulations intended to protect air resources. It is therefore important that an accurate and robust agricultural emission factors database exist to provide valid scientific support of these regulations. This paper highlights some of the recent work that was presented at the 2006 Workshop on Agricultural Air Quality in Washington, D.C. regarding NH3 emissions estimates and emission factors from agricultural sources in the U.S. and Europe. In addition, several best management practices are explored as the scientific community attempts to maximize the beneficial use of reactive nitrogen while simultaneously minimizing negative environmental impacts.}, number={2}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Aneja, Viney P. and Blunden, Jessica and James, Kristen and Schlesinger, William H. and Knighton, Raymond and Gilliam, Wendell and Jennings, Greg and Niyogi, Dev and Cole, Shawn}, year={2008}, pages={515–520} }
 @article{blunden_aneja_overton_2008, title={Modeling hydrogen sulfide emissions across the gas-liquid interface of an anaerobic swine waste treatment storage system}, volume={42}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-46749153762&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2008.03.016}, abstractNote={Hydrogen sulfide (H2S) is a colorless gas emitted during decomposition of hog manure that produces an offensive "rotten egg" smell and is considered a toxic manure gas. In the southeastern United States, anaerobic waste treatment lagoons are widely used to store and treat hog excreta at commercial hog farms. Hydrogen sulfide is produced as manure decomposes anaerobically, resulting from the mineralization of organic sulfur compounds as well as the reduction of oxidized inorganic sulfur compounds by sulfur-reducing bacteria. The process of H2S emissions from anaerobic waste treatment lagoons are investigated utilizing a two-film model with three different modeling approaches: Coupled Mass Transfer with Chemical Reactions Model with the assumption (1) pH remains constant in the liquid film (MTCR Model I) and (2) pH may change throughout the liquid film due to diffusion processes that occur within the film (MTCR Model II); and (3) a Mass Transfer Model which neglects chemical reactions (MTNCR Model) in the gas and liquid films. Results of model predictions are consistent with previous works, which show that flux is largely dependent on the physicochemical lagoon properties including sulfide concentration, pH, and lagoon temperature. Air temperature and low wind velocities (e.g., <3.25 m s−1) have negligible impact on flux. Results also indicate that flux values decrease with increased film thickness. The flux was primarily influenced by variations in the liquid film thickness, signifying that the H2S flux is driven by liquid-phase parameters. Model results were compared with H2S flux measurements made at a swine waste treatment storage lagoon in North Carolina using a dynamic emission flux chamber system in order to evaluate model accuracy in calculating lagoon H2S emissions. The MTCR Model II predicted the highest increase in emission rates as aqueous sulfide concentration was increased. The MTNCR Model showed the highest dependence on pH. All three models showed good agreement in diurnal comparison with flux measurements; however, each model significantly over predicted the measured flux rates. The MTNCR Model estimates were closest to experimental values, predicting 3–35 times the actual measured values.}, number={22}, journal={ATMOSPHERIC ENVIRONMENT}, author={Blunden, Jessica and Aneja, Viney P. and Overton, John H.}, year={2008}, month={Jul}, pages={5602–5611} }
 @article{blunden_aneja_2008, title={Characterizing ammonia and hydrogen sulfide emissions from a swine waste treatment lagoon in North Carolina}, volume={42}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-41449084288&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2007.02.026}, abstractNote={Emissions of atmospheric ammonia–nitrogen (NH3-N, where NH3-N=(14/17)NH3) and hydrogen sulfide (H2S) from a commercial anaerobic swine waste treatment lagoon (17,150 m2 at normal liquid level) were measured over a 1-year period. Continuous simultaneous measurements were made at the lagoon using a dynamic flow-through chamber system for ∼1 week during four seasons, October–November 2004 (fall), February 2005 (winter), April 2005 (spring), and June 2005 (summer) in an effort to examine diurnal and seasonal variability, and the respective relationships of NH3-N and H2S emissions to lagoon physicochemical properties. Continuously measured lagoon physicochemical parameters include lagoon surface temperature and lagoon pH. Aqueous lagoon samples were collected daily and analyzed for total Kjeldahl nitrogen (TKN), total ammoniacal nitrogen (TAN), and total sulfide concentration. TKN, TAN, and sulfide concentrations ranged from 400–650, 360–590, and 0.1–13.0 mg L−1, respectively. For NH3-N, the largest fluxes were observed during the summer (>4200 μg N m−2 min−1). During the fall and spring, average NH3-N fluxes were 1634±505 and >2495 μg N m−2 min−1, respectively. The lowest fluxes were observed during the winter where average flux values were 1290±246 μg N m−2 min−1. Fluxes for H2S were negligible during the winter season. Average fluxes increased during the fall (0.3±0.1 μg m−2 min−1) and spring (0.5±1.0 μg m−2 min−1), and highest flux values were observed during the summer (5.3±3.2 μg m−2 min−1). The seasonal NH3-N and H2S emission factors ranged from ∼10 to ∼40 kg N AU−1 yr−1 (1 AU=500 kg live animal weight) and ∼0 to ∼0.05 kg H2S AU−1 yr−1, respectively. Generally, the lagoon emissions for H2S were ∼3–4 orders of magnitude less than NH3-N. The gas fluxes were related to various physicochemical parameters including the pH and near-surface temperature of the lagoon, and the aqueous concentration of the respective gas.}, number={14}, journal={ATMOSPHERIC ENVIRONMENT}, author={Blunden, Jessica and Aneja, Viney P.}, year={2008}, month={Apr}, pages={3277–3290} }
 @article{blunden_aneja_westerman_2008, title={Measurement and analysis of ammonia and hydrogen sulfide emissions from a mechanically ventilated swine confinement building in North Carolina}, volume={42}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-41449109456&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2007.06.040}, abstractNote={Emissions of atmospheric ammonia–nitrogen (NH3–N, where NH3–N=(1417)NH3) and hydrogen sulfide (H2S) were measured from a finishing swine confinement house at a commercial pig farm in eastern North Carolina. Continuous simultaneous NH3–N and H2S emissions were made for ∼1-week period during four different seasons. The number of pigs contained in the house varied from ∼850 to 900 with average weights ranging from ∼38 to 88 kg. Average NH3–N concentrations were highest during the winter and spring sampling periods, 8.91±4.61 and 8.44±2.40 ppm, respectively, and lower during the summer and fall, 2.45±1.14 and 4.27±0.71 ppm, respectively. Measured average H2S concentrations were 673±282, 429±223, 47±18, and 304±88 ppb during winter, spring, summer, and fall, respectively. Generally, the H2S concentrations were approximately an order of magnitude less than NH3–N during winter, spring, and fall, and two orders of magnitude smaller during the summer season. The average ambient temperature ranged from 5.5 to 22.3 °C while the average barn temperature measured at the outlet fans ranged from 19.0 to 26.0 °C in the winter and summer, respectively. The average fan ventilation rates varied from 253 m3 min−1 during the fall sampling period to 1024 m3 min−1 during summer. Calculated total emission rates for both NH3–N and H2S were highest during the spring, 4519±1639 g N day−1 and 481±142 g day−1, respectively. Emissions were lowest during the fall season for NH3–N (904±568 g N day−1) and the summer season for H2S (82±49 g day−1). Normalized NH3–N emission rates were highest in winter and spring (33.6±21.9 and 30.6±11.1 g N day−1 AU−1, where 1 AU (animal unit)=500 kg) and lowest during summer and fall (24.3±12.4 and 11.8±7.4 g N day−1 AU−1). Normalized H2S emissions were highest during the winter and spring seasons (4.2±2.1 and 3.3±1.0 g day−1 AU−1) and were lowest in summer and fall (1.2±0.7 and 1.7±0.5 g day−1 AU−1).}, number={14}, journal={ATMOSPHERIC ENVIRONMENT}, author={Blunden, Jessica and Aneja, Viney P. and Westerman, Phillip W.}, year={2008}, month={Apr}, pages={3315–3331} }
 @article{aneja_blunden_roelle_schlesinger_knighton_niyogi_gilliam_jennings_duke_2008, title={Workshop on Agricultural Air Quality: State of the science}, volume={42}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-41449102642&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2007.07.043}, abstractNote={The first Workshop on Agricultural Air Quality: State of the Science was held at the Bolger Center in Potomac, Maryland from 4 to 8 June 2006. This international conference assembled approximately 350 people representing 25 nations from 5 continents, with disciplines ranging from atmospheric chemistry to soil science. The workshop was designed as an open forum in which participants could openly exchange the most current knowledge and learn about numerous international perspectives regarding agricultural air quality. Participants represented many stakeholder groups concerned with the growing need to assess agricultural impacts on the atmosphere and to develop beneficial policies to improve air quality. The workshop focused on identifying methods to improve emissions inventories and best management practices for agriculture. Workshop participants also made recommendations for technological and methodological improvements in current emissions measurement and modeling practices. The workshop commenced with a session on agricultural emissions and was followed by international perspectives from the United States, Europe, Australia, India, and South America. This paper summarizes the findings and issues of the workshop and articulates future research needs. These needs were identified in three general areas: (1) improvement of emissions measurement; (2) development of appropriate emission factors; and (3) implementation of best management practices (BMPs) to minimize negative environmental impacts. Improvements in the appropriate measurements will inform decisions regarding US farming practices. A need was demonstrated for a national/international network to monitor atmospheric emissions from agriculture and their subsequent depositions to surrounding areas. Information collected through such a program may be used to assess model performance and could be critical for evaluating any future regulatory policies or BMPs. The workshop concluded that efforts to maximize benefits and reduce detrimental effects of agricultural production need to transcend disciplinary, geographic, and political boundaries. Also, such efforts should involve natural and social scientists, economists, engineers, business leaders, and decision makers. The workshop came to the conclusion that through these collaborative efforts improvements in air quality from agricultural practices will begin to take effect.}, number={14}, journal={ATMOSPHERIC ENVIRONMENT}, author={Aneja, Viney P. and Blunden, Jessica and Roelle, Paul A. and Schlesinger, William H. and Knighton, Raymond and Niyogi, Dev and Gilliam, Wendell and Jennings, Greg and Duke, Clifford S.}, year={2008}, month={Apr}, pages={3195–3208} }
 @article{aneja_blunden_claiborn_rogers_2006, title={Dynamic atmospheric chamber systems: Applications to trace gas emissions from soil and plant uptake}, volume={6}, ISBN={1466-6650}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33746358849&partnerID=MN8TOARS}, DOI={10.1504/ijgenvi.2006.010157}, abstractNote={Atmospheric emissions, transport, transformation and deposition of trace gases may be simulated through chambers. The dynamic flow-through chamber system has been developed in response to a need to measure emissions of nitrogen, sulphur and carbon compounds for a variety of field applications. Oxides of nitrogen (NO, NO2, NOY) emissions have been measured from agricultural fertilised/unfertilised soils. Ammonia-nitrogen (NH3–N) and reduced organic sulphur compound emissions have been measured using this same technique across a gas-liquid and soil-atmosphere interface at swine waste treatment anaerobic storage lagoons and in agricultural fields. Similar chamber systems have also been deployed to measure the uptake of nitrogen, sulphur, ozone and hydrogen peroxide gases by crops and vegetation to examine atmospheric-biospheric interactions. Emission measurements compare well with a coupled gas-liquid transfer with chemical reaction model as well as a US Environmental Protection Agency (EPA) WATER9 model.}, number={2-3}, journal={International Journal of Global Environmental Issues}, author={Aneja, Viney and Blunden, J. and Claiborn, C.S. and Rogers, H.H.}, year={2006}, pages={253–269} }
 @article{blunden_aneja_lonneman_2005, title={Characterization of non-methane volatile organic compounds at swine facilities in eastern North Carolina}, volume={39}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-26844482025&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2005.03.053}, abstractNote={Samples were collected and analyzed in a field study to characterize C2–C12 volatile organic compounds (VOCs) emitted at five swine facilities in Eastern North Carolina between April 2002 and February 2003. Two sites employed conventional lagoon and field spray technologies, while three sites utilized various alternative waste treatment technologies in an effort to substantially reduce gaseous compound emissions, odor, and pathogens from these swine facilities. More than 100 compounds, including various paraffins, olefins, aromatics, ethers, alcohols, aldehydes, ketones, halogenated hydrocarbons, phenols, and sulfides were positively identified and quantified by Gas Chromatographic/Flame Ionization Detection (GC/FID) analysis and confirmed by Gas Chromatographic/Mass Spectrometry (GC/MS). GC/MS analysis of one particularly complex sample collected assisted in providing identification and retention times for 17 sulfur-type VOCs including dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide as well as many other VOCs. Highest VOC concentration levels measured at each of the facilities were near the hog barn ventilation fans. Total measured VOCs at the hog barns were typically dominated by oxygenated hydrocarbons (HCs), i.e., ethanol, methanol, acetaldehyde, and acetone. These compounds, in addition to other oxygenated VOCs measured at the various sites, generally represented ∼37–73% of net total measured VOCs that were emitted from the hog barns at the various sites. Dimethyl sulfide and dimethyl disulfide, both recognized as malodorous compounds, were determined to have higher concentration levels at the barns than the background at every farm sampled with the exception of one farm during the warm sampling season.}, number={36}, journal={ATMOSPHERIC ENVIRONMENT}, author={Blunden, J and Aneja, VP and Lonneman, WA}, year={2005}, month={Nov}, pages={6707–6718} }