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  • 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

Evaluation of a Rice/Soy Fermentate on Broiler Performance, Litter Characteristics, and Fecal Odorant Volatilization

Williams, Mallori 2012 August 1900 (has links)
The objective of this research was to determine the effect of a rice/soy fermentate when included in broiler diets and spray applied as a litter amendment on broiler performance, litter characterization, and ammonia and odorant volatilization. A series of three experiments were conducted to evaluate the effectiveness of the fermentate to reduce ammonia and odor compound volatilization when spray-applied to on recycled broiler litter. In experiment 1, spray-applying the two fermentate products did not affect ammonia volatilization; however the methodology was verified, as reductions were observed in the positive control. In experiment 2, spray application of the rice/soy fermentate did not have any impact on litter characteristics or average broiler body weight. However spray application of the rice/soy fermentate significantly reduced (P<0.05) observed mortality at the conclusion of the experiment. In experiment 3, spray application of the two fermentate products on fresh pine shavings following two activation times did reduce ammonia volatilization; although significant (p < 0.05) differences were observed in carbon and nitrogen content on day 43 and nitrogen content on day 35. Two experiments were conducted to evaluate the effectiveness of two fermented rice/soy products on volatilization of fecal odor compound volatilization and performance parameters when included in broiler diets. In experiment 1, the addition of fermentate B at 900 g/ton increased (p < 0.05) d 21 body weight. The inclusion of both fermentates (A and B) resulted in significant decreases (p < 0.05) in multiple volatile organic compounds, strongly associated with odor related to poultry. In experiment 2, the addition of fermentate B at 900 g/ton resulted in a significant increase (p < 0.05) in d 14 body weight. Inclusion of both rice/soy fermentates (A and B) significantly increased (p < 0.05) carcass weights. Additionally, significant reductions (p < 0.05) were observed in day 21 and 42 fecal pH with both fermentates (A and B). Taken in totality, these data demonstrate the ability of a rice/soy fermentate to alter litter nutrient content and intestinal environment resulting in increased nitrogen sequestering, reduced digest pH, reduce odorant volatilization, increased early bird weight, and reduce early mortality.
12

Reduction of odors associated with chlorine dioxide applications to drinking water /

Orr, Margaret Prehn, January 1990 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 152-157). Also available via the Internet.
13

Odor in the global environmental context: The effect of odor context reinstatement on memory

Finch, Dustin D. 06 August 2021 (has links)
Previous research has demonstrated that memory is dependent on the environmental context; memory is better when the same environmental context cues present at study are reinstated at test as compared to when they are not. This finding is called context reinstatement effects (Godden & Baddeley, 1975; Smith, Glenberg, and Bjork, 1978; Smith & Vela, 2001). What is unclear is whether study items are associated with the global context or with unique features within the study environment. We tested whether reinstating a singular feature of a global environment, the odor present during study, was sufficient to produce context reinstatement effects. These results indicated that, in a global environmental context, the global context is not being used as a cue for all the studied items rather than unique aspects of the environment serving as unique cues.
14

The Evaluation of Chemical Reaction Dynamics within Swine-Raising Facility: Implications to Odor Evolution and Assessment of Abatement Strategies

Wynn, Andrew Joseph 10 May 2003 (has links)
This research investigated the chemodynamics of the underdrains found at swine- raising facilities. The maintenance of aerobic conditions and introduction of aerobic bacteria to expedite the treatment process and control odor formation were investigated. A pilot-scale system that mimicked an industrial swine-raising facility was used in this study. Aeration and aeration with bacterial seed additions were evaluated against a standard pit recharge system, which served as the control. The effectiveness was measured using water quality testing, odor assessments by a human sensory panel, and air phase measurements of hydrogen sulfide and ammonia. The results indicated that both aeration and aeration with seeding under low loading condition were effective in reducing BOD, COD, volatile acids, and phenol concentration as well as overall odor intensity as compared to the control; however, neither was effective in reducing the ammonia, phosphate, or total solids concentrations. At mid and high loadings, little benefit was observed.
15

Manipulation of Microbial Metabolic Pathways for the Reduction of Sulfide Production

Zuller, Charles David 10 May 2003 (has links)
A bacterial additives treatment experiment was conducted to assess the microbial and biochemical changes in stored swine manure. Nitrate salt was added to a slurry of swine waste collected from a waste storage pit to identify the effects of varying levels of nitrate upon the microbial community and the resulting metabolic changes. This research was an attempt to reduce the formation of odorous sulfur-containing compounds and to increase the formation of odorless nitrogen gas by manipulating the metabolic pathways in anaerobic decomposition of the organic matter within manure. Sulfide production from swine wastewater was reduced approximately 45 percent with the addition of 1500 mg/l or more of nitrate to the wastewater.
16

Preventive control of ammonia and odor emissions during the active phase of poultry manure composting

Zhang, Wenxiu 05 1900 (has links)
Traditional measures used in the composting industry for ammonia and odor emissions control are those involving collection and treatment such as thermal oxidation, adsorption, wet scrubbing and biofiltration. However, these methods do not address the source of the odor generation problem. The primary objective of this thesis research was to develop preventive means to minimize ammonia and odor emissions, and maximize nitrogen conservation to increase the agronomic value of compost. Laboratory-scale experiments were performed to examine the effectiveness of various technologies to minimize these emissions during the active phase of composting. These techniques included precipitating ammonium into struvite in composting matrix before it release to outside environment; the use of chemical and biological additives in the form of yeast, zeolite and alum; and the manipulation of key operational parameters during the composting process. The fact that struvite crystals were formed in manure composting media, as verified by both XRD and SEM-EDS analyses, represents novel findings from this study. This technique was able to reduce ammonia emission by 40-84%, while nitrogen content in the finished compost was increased by 37-105%. The application of yeast and zeolite with dosages of 5-10% enhanced the thermal performance of composting and the degree of degradation, and ammonia emission was reduced by up to 50%. Alum was found to be the most effective additive for both ammonia and odor emission control; ammonia emission decreased by 45-90% depending on the dosage, and odor emission assessed via an dynamic dilution olfactometer was reduced by 44% with dosages above 2.5%. This study reaffirmed that aeration is the most influential factor to odor emission. An optimal airflow rate for odor control would be 0.6 L/min.kg dry matter with an intermittent aeration system. Quantitative relationships between odor emission and key operational parameters were determined, which would enable “best management practices” to be devised and implemented for composting. An empirical odor predictive model was developed to provide a simple and direct means for simulation of composting odor emissions. The effects of operating conditions were incorporated into the model with multiplicative algorithm and linearization approximation approach. The model was validated with experimental observations.
17

Preventive control of ammonia and odor emissions during the active phase of poultry manure composting

Zhang, Wenxiu 05 1900 (has links)
Traditional measures used in the composting industry for ammonia and odor emissions control are those involving collection and treatment such as thermal oxidation, adsorption, wet scrubbing and biofiltration. However, these methods do not address the source of the odor generation problem. The primary objective of this thesis research was to develop preventive means to minimize ammonia and odor emissions, and maximize nitrogen conservation to increase the agronomic value of compost. Laboratory-scale experiments were performed to examine the effectiveness of various technologies to minimize these emissions during the active phase of composting. These techniques included precipitating ammonium into struvite in composting matrix before it release to outside environment; the use of chemical and biological additives in the form of yeast, zeolite and alum; and the manipulation of key operational parameters during the composting process. The fact that struvite crystals were formed in manure composting media, as verified by both XRD and SEM-EDS analyses, represents novel findings from this study. This technique was able to reduce ammonia emission by 40-84%, while nitrogen content in the finished compost was increased by 37-105%. The application of yeast and zeolite with dosages of 5-10% enhanced the thermal performance of composting and the degree of degradation, and ammonia emission was reduced by up to 50%. Alum was found to be the most effective additive for both ammonia and odor emission control; ammonia emission decreased by 45-90% depending on the dosage, and odor emission assessed via an dynamic dilution olfactometer was reduced by 44% with dosages above 2.5%. This study reaffirmed that aeration is the most influential factor to odor emission. An optimal airflow rate for odor control would be 0.6 L/min.kg dry matter with an intermittent aeration system. Quantitative relationships between odor emission and key operational parameters were determined, which would enable “best management practices” to be devised and implemented for composting. An empirical odor predictive model was developed to provide a simple and direct means for simulation of composting odor emissions. The effects of operating conditions were incorporated into the model with multiplicative algorithm and linearization approximation approach. The model was validated with experimental observations.
18

Odour nuisance from restaurants and its control /

So, Tak-wing. January 1993 (has links)
Thesis (M. Sc.)--University of Hong Kong, 1993.
19

Odour control & legislation for the large offensive smell facilities in Hong Kong /

Kwan, Yiu-keung, John. January 1996 (has links)
Thesis (M. Sc.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 74-79).
20

Preventive control of ammonia and odor emissions during the active phase of poultry manure composting

Zhang, Wenxiu 05 1900 (has links)
Traditional measures used in the composting industry for ammonia and odor emissions control are those involving collection and treatment such as thermal oxidation, adsorption, wet scrubbing and biofiltration. However, these methods do not address the source of the odor generation problem. The primary objective of this thesis research was to develop preventive means to minimize ammonia and odor emissions, and maximize nitrogen conservation to increase the agronomic value of compost. Laboratory-scale experiments were performed to examine the effectiveness of various technologies to minimize these emissions during the active phase of composting. These techniques included precipitating ammonium into struvite in composting matrix before it release to outside environment; the use of chemical and biological additives in the form of yeast, zeolite and alum; and the manipulation of key operational parameters during the composting process. The fact that struvite crystals were formed in manure composting media, as verified by both XRD and SEM-EDS analyses, represents novel findings from this study. This technique was able to reduce ammonia emission by 40-84%, while nitrogen content in the finished compost was increased by 37-105%. The application of yeast and zeolite with dosages of 5-10% enhanced the thermal performance of composting and the degree of degradation, and ammonia emission was reduced by up to 50%. Alum was found to be the most effective additive for both ammonia and odor emission control; ammonia emission decreased by 45-90% depending on the dosage, and odor emission assessed via an dynamic dilution olfactometer was reduced by 44% with dosages above 2.5%. This study reaffirmed that aeration is the most influential factor to odor emission. An optimal airflow rate for odor control would be 0.6 L/min.kg dry matter with an intermittent aeration system. Quantitative relationships between odor emission and key operational parameters were determined, which would enable “best management practices” to be devised and implemented for composting. An empirical odor predictive model was developed to provide a simple and direct means for simulation of composting odor emissions. The effects of operating conditions were incorporated into the model with multiplicative algorithm and linearization approximation approach. The model was validated with experimental observations. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

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