In US, agricultural animal production accounts for 70% of total ammonia (NH3) emission and adversely affects human health, animal health and welfare, and the environment. Poultry industry is an important food production sector and contributes to 60% ($470 billion) of U.S. agriculture economy. Due to the nature of poultry production, it is the largest NH3 emission contributor among other animal productions. Inside poultry house, high level of NH3 negatively affects weight gain, feed conversion, respiratory and immune system of chickens, and threatens viability and sustainability of poultry industry. After being emitted from poultry house, NH3 undergoes dispersion, chemical reaction, and deposition processes, which have detrimental impacts on human health and ecosystem in neighboring communities. Though there is an urgent need to control and manage NH3 emission from poultry facilities, no regulation is available due to lack of effective tools for NH3 emission measurement.
The ultimate goal of this study is to develop a series of models for assessing NH3 emission, distribution, and dispersion within and from manure-belt layer houses, which can be utilized as tools for future NH3 regulation and mitigation. The specific objectives are to:
- Measurement of NH3 concentration and emission inside and at downwind of commercial manure-belt layer houses;
- Development of a mechanism model to quantify ammonia emission from poultry layer manure using lab-scale wind tunnel experiments;
- Development of a farm-scale model to estimate daily ammonia emission from commercial manure-belt layer houses for evaluation of mitigation strategies and establishment of fair regulation;
- Development of three-dimensional Computational Fluid Dynamics (CFD) models to assess NH3 distribution inside manure-belt layer houses; and
- Assessment of applicability of AERMOD and CALPUFF dispersion models to estimate NH3 dispersion and deposition in neighboring community.
The outcomes of this study can be used to
1) effectively estimate NH3 emission from poultry house for regulation and mitigation purpose;
2) assess health risk of chicken and farm workers in poultry facilities, and the residence living in the neighboring community; and
3) evaluate the ventilation efficiency of potential ventilation system or new housing structure for improved air quality.
Relevant publications can be found here:
- Modeling of indoor environment and ammonia emission, distribution, and dispersion within and from manure-belt layer houses. (PhD Dissertation). Link
- CFD modelling of airflow pattern and thermal environment in a commercial manure-belt layer house with tunnel ventilation. Link
- CFD modeling of airflow, thermal environment, and ammonia concentration distribution in a commercial manure-belt layer house with mixed ventilation systems. Link
- Using CFD simulations to develop an upward airflow displacement ventilation system for manure-belt layer houses to improve the indoor environment. Link
If you have any question or comment, please contact Dr. Lingying Zhao at email@example.com. Your feedback is much appreciated!