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Abstract Ammonia is a major odoriferous component in the vent gas of the fermentation process of poultry manure compost. To prevent environmental problems, it is full-scale and a lab-scale biotrickling filters (BTF) were used for treatment of ammonia in air streams. The full-scale BTF was constructed by reinforced concrete (inner size = 6 m square ¡Ñ 5 m height) with PVC plate packings (total volume =6 m square ¡Ñ 3 m height = 108 m3 , specific area = 100 m2/m3). Long-term (357 days) experimental results show that, in the conditions of gas empty-bed-retention time EBRT = 35-77 s, liquid-gas ratio L/G = 5-11 L/m3, and recirculation liquid pH = 6.5-6.8, 6.5-29.8 ppm (average 14.3 ppm) ammonia in the influent gas could be reduced to 0-2.0 ppm (average 0.66 ppm). Daily rates were supplementary water = 0.400 m3, discharge water = 0.360 m3, supplementary H3PO4 (85%) = 0.28 kg. With the average volumetric ammonia loading of 0.66 g NH3-N/m3h, the system could achieve an average nitrification efficiency of 62% without supplementary glucose. Ammonia removal efficiencies of over 90% were obtained with recirculation liquid pH¡Ø6.8, and below 22% with pH¡Ù7.33. The lab-scale BTF consisted of a set of two-stage-in-series biotrickling filters, an influent gas supply system, and a liquid recirculation system. Each stage of the biotrickling filter was constructed from a 20 cm ¡Ñ 200 cm (inside diameter ¡Ñ height) acrylic column packed with cokes (average diameter = 3.0 cm and specific area = 150 m2/m3) of 125 cm height. Experimental results indicate that a time of 30 days was required for development of biofilms for nitrification of the absorbed ammonia from the gas. Long-term (187 days) experimental results show that, in the conditions of EBRT = 7.25 s, L/G=7.7 L/m3, and liquid pH=6.65, 230 ppm ammonia in the influent gas could be reduced to 4.0 ppm. With the volumetric ammonia loading of less than 7.37 g NH3-N/m3h, the system could achieve ammonia removal and nitrification efficiencies of 98 and 94%, respectively, without supplementary glucose. However, with a loading of 13.1 g NH3-N/m3h, both decreased gradually due to a lake of carbon (glucose) source and an accumulation of nitrite and nitrate in the recirculation liquid.

The environmental impacts of broiler production have recently gained considerable public attention due to concerns regarding the amount of ammonia (NH3) released into the atmosphere from poultry facilities. Sound scientific data are needed to accurately estimate the production of manure waste products and gaseous emissions. This research project was undertaken to quantify nitrogen (N) loss through air emissions from a broiler grow-out facility over 18 consecutive flocks using the mass balance method. Measurement of litter and caked litter (cake) mass at the end of each flock allowed for the calculation of litter and cake production rates for broilers reared on recycled rice hull litter. Nutrient (nitrogen, phosphorus, and potassium) content of all litter materials was also measured. Broilers were reared in a research facility under simulated commercial conditions. All input materials (birds, feed, and litter) used in this study were obtained directly from a commercial broiler integrator to assure applicability to the broiler industry. The litter management technique of ??top-dressing?? was also investigated to determine its effects on N emissions and litter and cake production rates. Nitrogen emissions, litter and cake production rates, and nutrient density of litter materials were found to vary significantly between flocks reared at different times of the year. Nitrogen emissions were significantly greater for summer flocks than winter flocks. Average N loss over all 18 flocks was 11.07 g N/kg of marketed broiler (g N/kg). Nitrogen partitioning as a percentage of inputs averaged 15.29, 6.84, 55.52, 1.27, and 21.08% for litter, caked litter, broiler carcasses, mortalities and nitrogen loss, respectively, over all 18 flocks. Litter and cake production was lower in the summer compared to winter. Average litter, cake, and all litter (litter + cake) production was 153.3, 74.8, and 228.2 g of dry litter material/kg of marketed broiler. Litter and cake phosphorus and potassium content was elevated during summer flocks, while litter material N content decreased in summer flocks. Therefore, season of the year is an important factor that scientists and broiler producers must take into account when performing measurements and calculations, sampling litter materials and air emissions, and developing nutrient management plans.

published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

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A protocol was developed to measure ammonia emission concentrations from dairies using an isolation flux chamber. A hybrid dairy in Comanche county, Texas, was measured for one week each during August 2002 and January 2003. Sixty total ammonia samples were taken from the free stall barn, open lot, mixing tank, separated solids, compost, and two lagoons using the developed protocol. The ammonia concentration measurements were made using a chemiluminescence analyzer located inside a mobile laboratory. From the emission concentrations recorded, it was estimated that 9.68 metric tons of ammonia were produced from this dairy per year. An emission factor of 13.34 ± 28.80 kilograms per day per thousand head of cattle (kg/day/1000 head) was estimated for this dairy (±95% confidence intervals) during summer conditions. For winter conditions the emission factor was 12.05 ± 12.89 kg/day/1000 head. The 11% difference of the emission factors from summer to winter conditions was predominantly from the change in ambient and control volume temperatures (a mean difference of approximately 25 degrees Celsius), differences in source temperatures, and seasonal variability in husbandry. The adsorption of ammonia onto different polymer tubing used in pollutant stream conveyance was researched for possible systematic losses. Teflon and low density polyethylene (LDPE) were tested for ammonia losses with treatments of: temperature, length, and inlet concentration. Inlet concentration and temperature were significant factors used to describe ammonia adsorption for Teflon, whereas LDPE was also affected by tubing length. These factors were used to create a model to correct the summer dairy measurements for ammonia losses, resulting in an emission factor increase of 8.3% over the original value obtained from the flux chamber. A nitrogen mass balance was performed to estimate the amount of nitrogen available for ammonia formation as excreted - 177.5 kilograms per year per animal (wet basis). The amount of ammonia excreted per year was also estimated to be 26.63 kilograms per year. The measured ammonia emitted from the dairy was five times less than the ammonia excreted and thirty-six times less than the total nitrogen excreted.