Browsing by Author "Rumsey, Ian Cooper"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    An Assessment of Ammonia Emissions from Water-holding Structures for Hog Farms: Lagoon and Spray Technology and Potential Environmentally Superior Technologies
    (2004-08-12) Rumsey, Ian Cooper; Dr Viney P. Aneja, Committee Co-Chair; Dr S.Pal Arya, Committee Co-Chair
    Globally, the largest source of atmospheric NH3 is domestic animal waste contributing 20-35 Tg of nitrogen per year. In North Carolina, hog waste accounts for 47% of all ammonia emissions in North Carolina. This is the result of a huge increase in hog population since the 1980's from 3 million to 10 million. Currently swine waste is managed using Lagoon and Spray Technology (LST) also known as 'conventional' technology. A LST uses anaerobic lagoons to store the hog waste, and effluent from lagoons is sprayed on surrounding crops as a source of nutrients. This technology lead to a number sources of ammonia emissions, thus there are a number of environmental problems associated with swine facilities. The need for developing sustainable solutions for managing the hog waste problem is critical for shaping the future of hog farms in North Carolina. As a result of this, an agreement between the North Carolina Attorney General and several farming companies was reached to develop environmentally superior technologies (EST's) for swine facilities. The objective of this study was to quantitatively compare the emissions from the water-holding structures at the two LST farms (Moore farm and Stokes farm) and the three EST farms, and to evaluate the effectiveness of each technology. The three potential EST's were (1) EKOKAN: Up-flow Bio-filtration system, located at Brown's of Carolina # 93, (2) BEST: Solids separation/gasification for energy and ash recovery centralized system, located at Corbett # 1,3,4 farms, and (3) Super Soils: Solids separation/nitrification-denitrification/soluble phosphorus removal/solids processing system, located at Goshen Ridge farm. Measurements of NH3 flux were limited to two, two-week long periods, representing warm and cold seasons. These were obtained by using a dynamic flow-through chamber system interfaced to a mobile laboratory containing the ammonia analyzer and the data acquisition system. During the sampling period, environmental parameters such as lagoon temperature, lagoon pH, and TAN were measured, as well as meteorological parameters such as wind speed, wind direction, air temperature, relative humidity, and solar radiation. In order to make a comparison of LST and EST's, an adjustment for differing environmental conditions was needed. This was achieved by the development of a conventional observational statistical model, which was developed by multiple linear regression analysis based on continuous flux measurements from two conventional farms during a warm and cold season. Ammonia emissions from both conventional and EST farms were normalized to the nitrogen excretion (E) at the hog farms to express the emissions as % E. Potential reductions in ammonia were evaluated by comparing % EEST at EST farms with %ECONV at conventional farms. Overall, all three EST's were found to be significant in reducing ammonia emissions. Super Soils was found to be the most effective, with NH3 emission reductions of 94.7% in the warm season, and 99% in the cold season. EKOKAN was found to be the next most effective, with reductions of 71.7 % and 42.7 % for the summer and spring sampling periods, respectively. The two BEST technologies were the least effective. There were large reductions for both Corbett # 1 and Corbett # 3,4 in the fall sampling period, 71.1% and 39.6% respectively. There were through extremely low reductions in the winter sampling period, with reductions of 13.6% for Corbett # 1 and 7.5% for Corbett # 3,4, respectively.
  • No Thumbnail Available
    Characterizing reduced sulfur compounds and non-methane volatile organic compounds emissions from a swine concentrated animal feeding operation
    (2010-04-26) Rumsey, Ian Cooper; Phillip W. Westerman, Committee Member; Daniel Q. Tong, Committee Member; Viney P. Aneja, Committee Chair; S. Pal Arya, Committee Member
    ABSTRACT RUMSEY, IAN COOPER. Characterizing reduced sulfur compounds and non-methane volatile organic compounds emissions from a swine concentrated animal feeding operation. (Under the direction of Viney P. Aneja.) Reduced sulfur compounds (RSCs) and non-methane volatile organic compounds (NMVOCs) emissions from concentrated animal feeding operations (CAFOs) have become a potential environmental and human health concern. Both RSCs and NMVOCs contribute to odor. In addition, RSCs also have the potential to form fine particulate matter (PMfine) and NMVOCs the potential to form ozone. Measurements of RSCs and NMVOCs emissions were made from both an anaerobic lagoon and barn at a swine CAFO in North Carolina. Emission measurements were made over all four seasonal periods. In each seasonal period, measurements were made from both the anaerobic lagoon and barn for ~1 week. RSC and NMVOCs samples were collected using passivated canisters. Nine to eleven canister samples were taken from both the lagoon and barn over each sampling period. The canisters were analyzed ex-situ using gas chromatography flame ionization detection (GC-FID). Hydrogen sulfide (H2S) measurements were made in-situ using a pulsed fluorescence H2S/SO2 analyzer. During sampling, measurements of meteorological and physiochemical parameters were made. H2S had the largest RSC flux, with an overall average lagoon flux of 1.33 ï ­g m-2 min-1. The two main RSCs identified by the GC-FID, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), had overall average lagoon fluxes an order of magnitude lower, 0.12 and 0.09 ï ­g m-2 min-1, respectively. Twelve significant NMVOCs were identified in lagoon samples (ethanol, 2-ethyl-1-hexanol, methanol, acetaldehyde, decanal, heptanal, hexanal, nonanal, octanal , acetone, methyl ethyl ketone, and 4-methylphenol). The overall average fluxes for these NMVOCs, ranged from 0.08 ï ­g m-2 min-1 (4-methylphenol) to 2.11 ï ­g m-2 min-1 (acetone). Seasonal H2S barn concentrations ranged from 72-631 ppb. DMS and DMDS seasonal concentrations were 2-3 orders of magnitude lower. There were six significant NMVOCs identified in barn samples (methanol, ethanol, acetone 2-3 butanedione, acetaldehyde and 4-methylphenol). Their overall average NMVOCs concentrations ranged from 2.87 ppb (4-methylphenol) to 16.21 ppb (ethanol). The overall average barn normalized emissions were 3.3 g day-1 AU-1 (AU (animal unit) = 500 kg) for H2S, 0.018 g day-1 AU-1 for DMS and 0.037 g day-1 AU-1 for DMDS. Normalized overall average NMVOC emissions ranged from 0.45 g day-1 AU-1 for ethanol to 0.16 g day-1 AU-1 for acetaldehyde. Barn H2S concentrations were generally one to two orders of magnitude above their odor thresholds. DMDS concentrations also regularly exceeded the lower limit of an odor threshold. Four NMVOCs (2-3 butanedione, decanal, 4-methylphenol and nonanal) had barn concentrations exceeding an odor threshold. Using overall average lagoon and barn emissions, the emissions from swine CAFOs in North Carolina were estimated. H2S had the largest RSC emission with an estimated North Carolina emission of 1.46 million kg yr-1, which was ~21% of total North Carolina H2S emissions. Ethanol was the NMVOC with the largest North Carolina emission with an emission of 206,367 kg yr-1. H2S manure emissions were modeled using a process based air-manure interface (A-MI) mass transfer model. Different approaches were used to calculate the three main components of the A-MI mass transfer model: the dissociation constant, the Henry’s law constant and the overall mass transfer coefficient. The A-MI mass transfer model performed fairly well in comparison to 15 minute average lagoon fluxes (r2 = 0.57, p<0.0001) and seasonal lagoon fluxes. It is hypothesized that with appropriate information on the overall mass transport coefficient, that the model could be applied to predict CAFO trace gas emissions from different manure surfaces, therefore providing a method for quantifying emissions in different production, management and environmental conditions.