Dissertation
Ammonia emissions management and modeling from storages of dairy manure
Washington State University
Doctor of Philosophy (PhD), Washington State University
05/2010
DOI:
https://doi.org/10.7273/000006057
Abstract
About 80% of the dairy cattle nitrogen (N) intake is excreted in urine and feces. Urinary-N is ~75% urea while fecal-N is mostly organic. These excretions are either flushed to an anaerobic lagoon or scraped to a manure pit. Estimates indicate that the largest portion (75-80%) of the total-N entering a dairy facility is lost as ammonia (NH3) from manure storages. Ammonia is a major gaseous pollutant emitted from livestock facilities. Besides its adverse environmental impact, the atmospheric NH3 can also affect both animal and human health. To manage and regulate NH3 emissions from animal manure, cost-effective technologies are needed to estimate and mitigate NH3 emissions. This research consisted of two parts: In part I, studies were conducted to compare NH3 emissions between post-collection storages of manure from the two most common dairy manure handling (flush and scrape) systems in the USA. Additional studies were performed to evaluate ammonia emissions mitigation based on urine-feces separation following excretions. In part II, empirical equations of two key components: the overall mass transfer coefficient of NH3 (KoL of NH3), and the dissociation constant of ammonium ion (Kd of NH4+) were developed to improve a process-based model of NH3 emissions from open manure storages. Model predictions were validated with measured emissions. Ammonia emissions fluxes were higher from post-collection storages of scraped manure storages than from storages of flushed manure. Separation of urine and feces did not indicate any advantage over conventional scrape system in the mitigation of ammonia emissions from post-collection storages. The developed non-linear model of KoL of NH3 as a function of lagoon-liquid temperature (TL), air velocity (Vair), air temperature (Tair), and total solids (TS) had a coefficient of determination (R2) of 0.83. The KoLs increased with TL and Vair but decreased with increase with Tair and TS concentrations. The model of Kd of NH4+ as a function of TL and TS concentrations had an R2 of 0.97. The Kd increased with increase in TL but decreased with increase in TS. Using these empirical equations, model predicted ammonia fluxes compared well with measured fluxes with a normalized mean error (NME) of 15%.
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Details
- Title
- Ammonia emissions management and modeling from storages of dairy manure
- Creators
- Venkata Kumar Vaddella
- Contributors
- Pius Ndegwa (Chair)Claudio Osvaldo Stockle (Committee Member) - Washington State University, Department of Biological Systems EngineeringJeffrey L. Ullman (Committee Member)DAVID R YONGE (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Biological Systems Engineering
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 142
- Identifiers
- 99901055025101842
- Language
- English
- Resource Type
- Dissertation