• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 24
  • 19
  • 10
  • 10
  • 10
  • 10
  • 10
  • 10
  • 1
  • 1
  • Tagged with
  • 58
  • 58
  • 20
  • 15
  • 9
  • 8
  • 8
  • 8
  • 8
  • 7
  • 7
  • 7
  • 7
  • 6
  • 6
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Reducing ammonia volatilization from liquid hog manure by using organic amendments

Subair January 1995 (has links)
No description available.
12

Lincomycin and Spectinomycin : persistence in liquid hog manure and their transport from manure-amended soil

Kuchta, Sandra Louise 03 March 2008
Antimicrobials administered to livestock can be excreted up to 80% in the feces and urine. Liquid swine manure from confined animal feeding operations is generally retained in lagoon storage until it is applied as a nutrient source to cropland. Thus, the applied manure becomes a possible source of antimicrobials to aquatic ecosystems. Veterinary antimicrobials have been detected in surface and ground waters in Canada, the United States and Europe, however, their environmental fate is not well known. Lincomycin and spectinomycin are two antimicrobials administered as a mixture to swine in the prairie region of Canada for the prevention of post-weaning diarrhea. In order to assess the potential for contamination of prairie wetlands, concentrations of both antimicrobials were monitored in the liquid manure from the nursery area of a commercial-scale barn during a 5-week study, and their persistence during simulated manure storage investigated. The potential for transport of lincomycin and spectinomycin to surface waters via surface runoff and to leach to groundwater was also assessed. This was achieved by monitoring manure-amended soil, simulated rainfall runoff, snow melt runoff and groundwater over a two-year period at two study sites in Saskatchewan, Canada following fall application of liquid swine manure from two commercial barns to crop and pasture land. Liquid chromatography coupled with tandem mass spectrometry was used to quantitate these antimicrobials in all matrix extracts. <p>In the nursery area of a commercial-scale barn, concentrations of lincomycin and spectinomycin in the cumulating liquid manure at the end of the study were equivalent to 32 and 3.0%, respectively, of doses administered in the feed. In a laboratory study, using fortified liquid manure, concentrations of both antimicrobials showed a rapid initial decrease during simulated lagoon storage, followed by a slower dissipation over a period of 5 months. The average time required for 50% dissipation of lincomycin was greater than one year (365 d) and was approximately 90 d for spectinomycin. <p>Lincomycin concentrations in soil (46.3 to 117 µg kg-1) collected immediately after fall manure application, decreased to non-detectable levels by mid-summer the following year. Lincomycin was present in simulated rainfall runoff (0.1 to 2.7 µg L-1) immediately after manure application with similar concentrations present in snow meltrunoff the following spring. Concentrations in groundwater were generally <0.005 µg L-1. Spectinomycin was not detected in the manure applied at the study sites nor in soil, runoff water or groundwater samples. This study confirms that some antimicrobials, including lincomycin, may be present in lagoon manure. Thus, the management practice of utilizing livestock manure from confined animal feeding operations as a plant nutrient source on cropland may result in antimicrobial transport to surface and ground waters.
13

Laboratory, semi-pilot and room scale control of H2S emission from swine barns using nitrite and molybdate

Moreno, Lyman Denis Ordiz 15 December 2009
Emission of odorous and gaseous compounds such as hydrogen sulphide (H2S) from livestock facilities can be a major impediment to its daily operations and potential expansion. Occupational and environmental concerns require the control of H2S emissions. A treatment approach used in the oil industry in which nitrite and/or molybdate are used as metabolic inhibitors to control the production of H2S in oil reservoirs was shown to be effective in controlling H2S emissions from swine manure.<p> The addition of nitrite and molybdate to swine manure was investigated in closed laboratory scale systems and then evaluated in semi-pilot scale open systems and in specifically designed chambers aiming to simulate an actual swine barn. The effect of manure age (extent of storage) on H2S emissions and the levels of nitrite and molybdate required for effective control of these emissions were assessed. Laboratory scale tests showed that emission of H2S was dependent on manure age. Fresh manure emitted the highest level of H2S and the level of emission decreased as manure age (1-6 months) increased. With fresh 1, 3, and 6-month old manures average H2S concentration in the headspace gas of the closed systems were 4856b460, 3431b208, 1037b98 ppm, and non-detectable (<0.4 ppm), respectively. This translated to lower levels of nitrite or molybdate required to control H2S emission with increase in manure age. When compared to molybdate, the addition of nitrite initially led to lower levels of H2S but its effect was only temporary and not as persistent as molybdate. In the semi-pilot and room scale tests H2S levels emitted from untreated fresh manure (831¡Ó26 ppm and 88.4 ppm, respectively), were significantly lower than those observed in the laboratory system (4856¡Ó460 ppm). Moreover, the levels of molybdate required to control the emission of H2S were much lower in both the semi-pilot system and in the room scale chamber than in the closed system (0.1-0.25 mM as opposed to 2 mM).<p> Small scale land application of manure treated with 0.1 mM molybdate did not raise the level of molybdenum in the soil that could cause potential toxicity to plants and animals. No major differences in the nutrient properties of the soils exposed to the treated and untreated manure were observed. Finally, a preliminary feasibility study of this treatment approach showed that the cost associated with this control approach was less than 1% of the total production cost.
14

Lincomycin and Spectinomycin : persistence in liquid hog manure and their transport from manure-amended soil

Kuchta, Sandra Louise 03 March 2008 (has links)
Antimicrobials administered to livestock can be excreted up to 80% in the feces and urine. Liquid swine manure from confined animal feeding operations is generally retained in lagoon storage until it is applied as a nutrient source to cropland. Thus, the applied manure becomes a possible source of antimicrobials to aquatic ecosystems. Veterinary antimicrobials have been detected in surface and ground waters in Canada, the United States and Europe, however, their environmental fate is not well known. Lincomycin and spectinomycin are two antimicrobials administered as a mixture to swine in the prairie region of Canada for the prevention of post-weaning diarrhea. In order to assess the potential for contamination of prairie wetlands, concentrations of both antimicrobials were monitored in the liquid manure from the nursery area of a commercial-scale barn during a 5-week study, and their persistence during simulated manure storage investigated. The potential for transport of lincomycin and spectinomycin to surface waters via surface runoff and to leach to groundwater was also assessed. This was achieved by monitoring manure-amended soil, simulated rainfall runoff, snow melt runoff and groundwater over a two-year period at two study sites in Saskatchewan, Canada following fall application of liquid swine manure from two commercial barns to crop and pasture land. Liquid chromatography coupled with tandem mass spectrometry was used to quantitate these antimicrobials in all matrix extracts. <p>In the nursery area of a commercial-scale barn, concentrations of lincomycin and spectinomycin in the cumulating liquid manure at the end of the study were equivalent to 32 and 3.0%, respectively, of doses administered in the feed. In a laboratory study, using fortified liquid manure, concentrations of both antimicrobials showed a rapid initial decrease during simulated lagoon storage, followed by a slower dissipation over a period of 5 months. The average time required for 50% dissipation of lincomycin was greater than one year (365 d) and was approximately 90 d for spectinomycin. <p>Lincomycin concentrations in soil (46.3 to 117 µg kg-1) collected immediately after fall manure application, decreased to non-detectable levels by mid-summer the following year. Lincomycin was present in simulated rainfall runoff (0.1 to 2.7 µg L-1) immediately after manure application with similar concentrations present in snow meltrunoff the following spring. Concentrations in groundwater were generally <0.005 µg L-1. Spectinomycin was not detected in the manure applied at the study sites nor in soil, runoff water or groundwater samples. This study confirms that some antimicrobials, including lincomycin, may be present in lagoon manure. Thus, the management practice of utilizing livestock manure from confined animal feeding operations as a plant nutrient source on cropland may result in antimicrobial transport to surface and ground waters.
15

Laboratory, semi-pilot and room scale control of H2S emission from swine barns using nitrite and molybdate

Moreno, Lyman Denis Ordiz 15 December 2009 (has links)
Emission of odorous and gaseous compounds such as hydrogen sulphide (H2S) from livestock facilities can be a major impediment to its daily operations and potential expansion. Occupational and environmental concerns require the control of H2S emissions. A treatment approach used in the oil industry in which nitrite and/or molybdate are used as metabolic inhibitors to control the production of H2S in oil reservoirs was shown to be effective in controlling H2S emissions from swine manure.<p> The addition of nitrite and molybdate to swine manure was investigated in closed laboratory scale systems and then evaluated in semi-pilot scale open systems and in specifically designed chambers aiming to simulate an actual swine barn. The effect of manure age (extent of storage) on H2S emissions and the levels of nitrite and molybdate required for effective control of these emissions were assessed. Laboratory scale tests showed that emission of H2S was dependent on manure age. Fresh manure emitted the highest level of H2S and the level of emission decreased as manure age (1-6 months) increased. With fresh 1, 3, and 6-month old manures average H2S concentration in the headspace gas of the closed systems were 4856b460, 3431b208, 1037b98 ppm, and non-detectable (<0.4 ppm), respectively. This translated to lower levels of nitrite or molybdate required to control H2S emission with increase in manure age. When compared to molybdate, the addition of nitrite initially led to lower levels of H2S but its effect was only temporary and not as persistent as molybdate. In the semi-pilot and room scale tests H2S levels emitted from untreated fresh manure (831¡Ó26 ppm and 88.4 ppm, respectively), were significantly lower than those observed in the laboratory system (4856¡Ó460 ppm). Moreover, the levels of molybdate required to control the emission of H2S were much lower in both the semi-pilot system and in the room scale chamber than in the closed system (0.1-0.25 mM as opposed to 2 mM).<p> Small scale land application of manure treated with 0.1 mM molybdate did not raise the level of molybdenum in the soil that could cause potential toxicity to plants and animals. No major differences in the nutrient properties of the soils exposed to the treated and untreated manure were observed. Finally, a preliminary feasibility study of this treatment approach showed that the cost associated with this control approach was less than 1% of the total production cost.
16

Performance Study on the Treatment of Odorous Gases from Composting of Swine Manure

Chang, Chi-lung 20 June 2005 (has links)
It has been confirmed that vented gases from swine manure compositing operations contain biodegradable ammonia and amines as main odorous compounds. The thesis focuses on the odor-removal performance from the gases by sparging them into an activated sludge aeration liquor in which the odorous compounds can be absorbed and biodegraded. An acrylic column (0.20 m i.d.¡Ñ1.2 mH) was used as the activated sludge aeration tank and a wooden case (1.0 mL¡Ñ0.6 mW¡Ñ0.6 mH) as a swine manure compositing tank. Seed sludge for the odor removal experiments was obtained from a swinery wastewater plant located at southern Taiwan. Both swine manure from the swinery and a pre-fermented composite sample obtained from a compositing plant located at East-southern Ping-Dong County were used for the odorous gas generation. Experiments were conducted at mixed liquor suspended solid (MLSS) concentrations of 2,250-2,750 mg/L, liquid pH of 6.4-6.6, and aeration intensities of 0.1-0.5 m3/m3.min. Results show that the experimental removal efficiencies for both ammonia and amines with, respectively, 18-50 and 180-250 ppm in the influent gas were greater than 80% with aerated activated sludge liquid depths of greater than 0.60 m within the tested aeration intensities. Keeping the activated sludge at around 25oC favored the biodegradation of the absorbed ammonia and amines and resulted in the removal of the compounds to around 85-95%. Temperatures of lower than 15oC shifted the removal to as low as 50-60% because of the limitations in both the biological growth and activity. Results from the study confirm that the activated sludge bioscrubbing approach should be applicable to odor control for the compositing plants.
17

Further composting of pig-manure disposed from the pig-on-litter (POL)system in Hong Kong

Tiquia, Sonia M. January 1996 (has links)
published_or_final_version / Ecology and Biodiversity / Doctoral / Doctor of Philosophy
18

Minimal aeration of swine manure for odor control.

Ghaly, Abdelkader Elmetwaly. January 1982 (has links)
A race track type oxidation ditch with a disc aerator was constructed on a model scale. Tests were conducted in deionized water to study the effect of some disc design parameters and system operating parameters on the oxygen transfer rate was affected by the disc speed, disc thickness, hole diameter, immersion depth and number of discs operated in parallel. / The effect of the manure concentration on the microbial growth was investigated in a batch culture operation. High manure concentration had an inhibitory effect on the microbial growth. / Data from batch culture operation were used to design a continuous culture operation. The latter was used to evaluate the concept of minimal aeration of swine manure for odor control. The effluent quality (as measured by odor level and the concentrations of COD, nitrogenous componds and solids) was dependent on the initial manure concentration and on the retention time. The effluent from the ditch was free of offensive odor and can be spread on land without causing odor pollution problem.
19

Influence of incubating liquid hog manure and monocalcium phosphate on phosphorus availability and fractionation

Sigrist, Andrew B. (Andrew Bernard) January 1993 (has links)
Incubation mixtures of liquid hog manure (LHM), with and without monocalcium phosphate (MCP) were added to an Ormstown silty clay loam and a Ste. Rosalie clay. Ryegrass (Lolium multiflorum Lam.) was cultivated in a pot study in order to determine yield, total P uptake and soil P content as affected by various P and manure treatments. / Aeration of LHM with MCP was successful in reducing ammonia volatilization by 62.4%. However, for both soils, neither of the treatments; LHM amended and aerated with MCP and applied at 32 t ha$ sp{-1}$ LHM containing 513 kg $ rm P sb2O sb5 ha sp{-1}$ from MCP nor LHM aerated without MCP applied at 32 t ha$ sp{-1}$ LHM, plus 513 kg $ rm P sb2O sb5 ha sp{-1}$ from MCP, significantly affected ryegrass yields compared to the lone addition of MCP fertilizer (513 kg $ rm P sb2O sb5 ha sp{-1}).$ Total P uptake in ryegrass was significantly higher for the incubated treatments in the Ste. Rosalie soil alone. / Although additions of LHM or MCP and LHM-MCP combinations affected Mehlich-III and Hedley P fractions, the incubation of MCP with LHM did not significantly increase either inorganic- or organic-P fractions when compared to MCP alone. Therefore, premixing MCP with the LHM had no effect on improving P availability in either the Ormstown or Ste. Rosalie soils.
20

Chemically enhanced gravitational solid-liquid separation for the management of phosphorus in liquid swine manure

Agomoh, Ikechukwu Vincent 11 September 2012 (has links)
This laboratory column (125 cm high, 15 cm diameter) research investigated solids and P removal from liquid swine manure amended with calcium carbonate, magnesium sulphate, alum and polyacrylamide (PAM). Results showed that PAM was the most effective amendment for enhancing solids removal from manure containing 1% initial total solids (TS). The effectiveness of PAM was lower at 5% and 8% than at 1% due to resuspension of solids occurring at settling times beyond 4 h. After 24 h of settling, P removal from non-amended manure was comparable to that in amended manure and decreased with TS concentration for all amendments except alum, which was equally effective at all TS concentrations. These results indicate that, for manure containing 1% TS, P can be adequately removed by gravity separation without addition of chemical amendments while alum is a more effective amendment for removing P from manure containing higher (5% and 8%) TS.

Page generated in 0.026 seconds