The effect of heat fluxes on ammonia emission from swine waste lagoon based on neural network analyses

Authors: Lovanh, Nanh; QUINTANA, ARTURO - Western Kentucky University; RYSZ, MACIEJ - University Of Iowa; Loughrin, John; MAHMOOD, REZAUL - Western Kentucky University

Submitted to: Journal of Environmental Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2014
Publication Date: 5/30/2014
Citation: Lovanh, N.C., Quintana, A., Rysz, M., Loughrin, J.H., Mahmood, R. 2014. The effect of heat fluxes on ammonia emission from swine waste lagoon based on neural network analyses. Journal of Environmental Science and Technology. 7(1):16-29.

Interpretive Summary: Swine waste lagoons are effective and low-cost tools to treat swine excreta but they are also responsible for emissions of numerous atmospheric pollutants including ammonia, greenhouse gases, and malodors. These pollutants are most prominent and controlled by interactions with the atmosphere and biochemical and physical processes occurring at lagoon interfaces. Ammonia and volatile organic compounds such as skatole, cresol, and indole, are thought to be important chemical constituents of offending odors to humans and a cause of discomfort and disease in the environment within and near confined animal feeding operations (CAFOs). Thus, any study on CAFOs from swine operations needs to address the issue of anaerobic lagoons as a source of atmospheric pollutants and the potential for devising emission reduction techniques. Understanding factors that affect ammonia emissions from swine waste lagoons or any animal waste receptacles is a necessary first step in deploying potential remediation options. In this study, we examined the various meteorological factors (i.e., air temperatures, solar radiation, and heat fluxes) that potentially affect ammonia emissions from swine waste lagoon. Ammonia concentrations were monitored using a gas analyzer. The ammonia emissions from the lagoon were monitored continuously for a twenty-four hour cycle, twice a week during a winter month at a height of fifty centimeters above the lagoon surface. Meteorological data were also monitored simultaneously. Heat fluxes were tabulated and correlated to the averaged ammonia concentrations. A mathematical model was built based on the most important meteorological parameters. The results from the model show that ammonia emissions from the swine waste lagoon were affected by incoming solar radiation and heat fluxes. Thus it is important to consider environmental conditions (i.e., meteorological parameters such as solar radiation, latent heat and etc.) in formulating management or abatement strategies for reducing ammonia emissions from swine waste lagoons or any other air pollutant emissions from livestock waste receptacles.

Technical Abstract: Understanding factors that affect ammonia emissions from swine waste lagoons or any animal waste receptacles is a necessary first step in deploying potential remediation options. In this study, we examined the various meteorological factors (i.e., air temperatures, solar radiation, and heat fluxes) that potentially affect ammonia emissions from swine waste lagoon. Ammonia concentrations were monitored using a photoacoustic gas analyzer. The ammonia emissions from the lagoon were monitored continuously for a twenty-four hour cycle, twice a week during a winter month at a height of fifty centimeters above the lagoon surface. Meteorological data were also monitored simultaneously. Heat fluxes were tabulated and correlated to the averaged ammonia concentrations (range of zero to 8.0 ppmv). Multi-layer perceptron (MLP) neural network predictive model was built based on the most important meteorological parameters. The results from MLP neural networks analysis show that ammonia emissions from the swine waste lagoon were affected by heat fluxes such as net solar radiation, sensible heat, and latent heat of vaporization. Thus it is important to consider environmental conditions (i.e., meteorological parameters such as solar radiation, latent heat and etc.) in formulating management or abatement strategies for reducing ammonia emissions from swine waste lagoons or any other air pollutant emissions from livestock waste receptacles.