Measurement and Modelling of Ammonia Emissions at Waste Treatment Lagoon-Atmospheric Interface

Abstract

Abstract. Global emissions of ammonia are approximately 75 Tg N/yr (1 Tg = 10 12 g). The major global source is excreta from domestic animals (∼ 32 Tg N −1 yr −1 ). Waste storage and treatment lagoons are used to treat the excreta of hogs in North Carolina (NC). Proteins and nitrogen rich compounds in the lagoon are converted to ammonia, through a series of biological and chemical transformations. The process of ammonia emission has been investigated using two different model approaches: (1) Coupled Mass Transfer with Chemical Reaction Model (Model I), and (2) Mass Transport without Chemical Reaction Model (Model II). A sensitivity analysis is performed with the models, and the model results are compared with ammonia emission experiments at a swine waste storage and treatment lagoon in NC using a dynamic emission flux chamber.Results of model predictions of emission flux indicate an exponential increase in ammonia flux with increasing lagoon temperature and pH, a linear increase with increasing lagoon total ammoniacal nitrogen (TAN), and a secondary degree increase with the increasing wind speed. In addition, the fluxes predicted by Model I are consistently larger than fluxes predicted by Model II. Experimental values of flux agreed well with model predictions, with the experimental values lying in different positions between the two model predictions under different physical and chemical conditions. Further, when compared to diurnal and seasonal experimental flux values, Model I corroborates the results in calm meteorological conditions (wind speed U10 = 1.5 m s −1 ). However, the observed results are better predicted by Model II during unstable conditions, when wind speeds are higher than 2.0 m s −1 and physical transfer process functions dominate.

Characterization of gas emissions from a Mediterranean broiler farm

“…Considering that higher ventilation flows tend to remove indoor pollutants, ventilation rates and gas concentrations tend to be inversely correlated . Apart from these considerations, gaseous emissions, particularly NH 3 , from a certain surface depend on the air velocity distribution over that surface (Aneja et al, 2001). Finally, during the day, bird activity also varies according to management practices (Calvet et al, 2009).…”

Environmental Conditions in Beef Deep-Bedded Mono-Slope Facilities: A Descriptive Study

“…Elevating the temperature of the soil has been shown to increase NH 3 losses from the surface of open feedlots (Sherwood et al, 2006) and from soils receiving urea fertilizer (Liu et al, 2007). Higher temperatures also increased NH 3 losses from waste treatment lagoons (Aneja et al, 2001) and poultry litter (Liu et al, 2006). Lockyer and Whitehead (1990) summarized nine experiments in which the volatilization of NH 3 from cattle urine applied to grass swards was assessed over 15-day periods using a system of wind tunnels.…”

Heat Flux Measurements and Modeling of Malodorous Compounds above an Anaerobic Swine Lagoon

“…This has led to numerous calculations of flux rates of ammonia (Aneja et al 2001;Blunden and Aneja 2008). Emission rates have been calculated using a number of different methods such as enclosed flux chambers (e.g., Aneja et al 2001;Blunden and Aneja 2008) and various micrometeorological techniques (e.g., Harper and Sharpe 2000;Phillips et al 2004). Regardless of the method employed, the objective has been to incorporate variables such as pH, wind speed, and temperature into models so that ammonia emissions may be reasonably modeled under varied conditions.…”