Mukhtar Saqib, Mutlu Atilla, Lacey Ronald E, Parnell Calvin B
Department of Biological and Agricultural Engineering, Texas A&M University, College Station, TX 77843, USA.
J Air Waste Manag Assoc. 2009 May;59(5):613-8. doi: 10.3155/1047-3289.59.5.513.
Studies show that agricultural and animal feeding operations (AFOs) contribute a considerable amount of ammonia (NH3) to the atmosphere. Agricultural NH3 emissions are recognized as an important air quality issue. Biological decomposition of manure from dairy operations results in emissions of NH3 and other gases. There is a need to determine NH3 emission factors (EFs) to compile annual NH3 inventories. NH3 emissions should be estimated from different ground-level area sources (GLAS) including open-lots (cows on earthen corrals), free-stalls (cows in barns), manure composting sites, primary and secondary lagoons, separated solids, and milking parlors. A protocol using flux chambers was used to determine NH3 EFs from different GLAS of a free-stall dairy in central Texas. Data including NH3 emissions from GLAS were collected during winter and summer seasons. NH3 concentration measurements were made using chemiluminescence-based analyzers. The EFs for the free-stall dairy were estimated as 11 +/- 4.9 (confidence interval [CI]) kg-NH3 x yr(-1) x head(-1) for summer and 4.7 +/- 4.9 kg-NH3 x yr(-1) x head(-1) for winter. The estimated annual NH3 EF was 8.4 +/- 4.9 kg-NH3 x yr(-1) head(-1) for this free-stall dairy. This seasonal difference was attributed to temperature, loading rate of dairy waste, and manure bacterial activity of GLAS. In winter, composted manure and free-stalls contributed nearly 77% of the total NH3 emissions for the dairy; however, in summer, two lagoons at the dairy contributed 65% of the overall NH3 emissions.
研究表明，农业和动物饲养作业（AFOs）向大气中排放了大量的氨（NH₃）。农业NH₃排放被认为是一个重要的空气质量问题。奶牛场粪便的生物分解会导致NH₃和其他气体的排放。需要确定NH₃排放因子（EFs）以编制年度NH₃清单。应从不同的地面源区域（GLAS）估算NH₃排放量，包括露天场地（土围栏中的奶牛）、自由牛舍（牛舍中的奶牛）、粪便堆肥场、一级和二级泻湖、分离出的固体以及挤奶厅。采用一种使用通量室的方案来确定德克萨斯州中部一个自由牛舍奶牛场不同GLAS的NH₃排放因子。在冬季和夏季收集了包括GLAS的NH₃排放数据。使用基于化学发光的分析仪进行NH₃浓度测量。该自由牛舍奶牛场夏季的排放因子估计为11±4.9（置信区间[CI]）kg-NH₃×yr⁻¹×头⁻¹，冬季为4.7±4.9 kg-NH₃×yr⁻¹×头⁻¹。该自由牛舍奶牛场的年NH₃排放因子估计为8.4±4.9 kg-NH₃×yr⁻¹×头⁻¹。这种季节差异归因于温度、奶牛场废弃物的装载率以及GLAS的粪便细菌活性。在冬季，堆肥粪便和自由牛舍贡献了奶牛场总NH₃排放量的近77%；然而，在夏季，奶牛场的两个泻湖贡献了总体NH₃排放量的65%。
