Huang Dandan, Guo Huiqing
a Biological Engineering , University of Saskatchewan , Saskatoon , SK , Canada.
b Mechanical Engineering , University of Saskatchewan , Saskatoon , SK , Canada.
J Air Waste Manag Assoc. 2017 Oct;67(10):1092-1105. doi: 10.1080/10962247.2017.1329172. Epub 2017 Jun 2.
This study characterized the seasonal concentration (C) and emission (E) patterns of odor, ammonia (NH), and hydrogen sulfide (HS) over the course of a whole year and their diurnal patterns in cold, warm, and mild seasons for a naturally ventilated free-stall dairy barn. It was found that seasonal odor and NH and HS emissions varied greatly: from 17.2 to 84.4 odor units (OU) sec AU (AU: animal unit, 500 kg of animal body mass), from 0.27 to 0.92 mg sec AU, and from 3 to 105 μg sec AU, respectively. The overall concentrations of odor and NH were higher in the winter, whereas the emissions were higher in the mild and warm seasons. Diurnal variation was most significant for odor emission (OE) in the mild season when the ratio of maximum (279.2 OU sec AU) to minimum value (60.5 OU sec AU) was up to 4.6. The indoor air quality was also evaluated by considering not only the health effect of individual gases, but also the additive effect of NH and HS. Results showed that the indoor air quality was poorest in cold seasons when NH C could exceed the threshold limit set out in occupational health regulation, and in fact could worsen due to the additive effect of the two gases. Further, it was suggested NH was a good indicator for predicting odor concentration (OC) or OE. The impact of climatic parameters on odor and gases were also examined, and it was found ventilation rate (VR) negatively affected OC and NH C, but positively impacted OE and NH E. Using 70% of the total data, a multilinear model for OE was developed as a function of VR and indoor relative humidity and was validated to be acceptable using the rest of the data.
Diurnal and seasonal variations of odor, NH, and HS concentrations and emissions were monitored for a naturally ventilated dairy barn in a cold region. The emission factors were calculated and indoor air quality was evaluated. The overall odor and NH concentrations were higher in winter, whereas emissions were higher in the mild and warm seasons. Diurnal variation was most significant for odor emission in the mild season, when the ratio of maximum to minimum value was up to 4.6. The results can be used to estimate odor and gas emissions from other dairy barns in Canada and other cold regions.
本研究对一个自然通风的散栏式奶牛场全年的气味、氨气（NH₃）和硫化氢（H₂S）的季节浓度（C）和排放（E）模式及其在寒冷、温暖和温和季节的日变化模式进行了表征。研究发现，季节性气味以及NH₃和H₂S的排放差异很大：分别为17.2至84.4气味单位（OU）·秒⁻¹·动物单位（AU：动物单位，500千克动物体重）、0.27至0.92毫克·秒⁻¹·动物单位以及3至105微克·秒⁻¹·动物单位。气味和NH₃的总体浓度在冬季较高，而排放则在温和和温暖季节较高。在温和季节，气味排放（OE）的日变化最为显著，此时最大值（279.2 OU·秒⁻¹·动物单位）与最小值（60.5 OU·秒⁻¹·动物单位）的比值高达4.6。室内空气质量评估不仅考虑了单一气体的健康影响，还考虑了NH₃和H₂S的相加作用。结果表明，在寒冷季节室内空气质量最差，此时NH₃浓度可能超过职业健康法规规定的阈值，实际上由于两种气体的相加作用空气质量可能会恶化。此外，研究表明NH₃是预测气味浓度（OC）或OE的良好指标。还研究了气候参数对气味和气体的影响，发现通风率（VR）对OC和NH₃浓度有负面影响，但对OE和NH₃排放有正面影响。利用70%的总数据，建立了一个作为VR和室内相对湿度函数的OE多线性模型，并使用其余数据验证其可接受性。
对寒冷地区一个自然通风的奶牛场的气味、NH₃和H₂S浓度及排放的日变化和季节变化进行了监测。计算了排放因子并评估了室内空气质量。气味和NH₃的总体浓度在冬季较高，而排放则在温和和温暖季节较高。在温和季节，气味排放的日变化最为显著，此时最大值与最小值的比值高达4.6。研究结果可用于估算加拿大和其他寒冷地区其他奶牛场的气味和气体排放。
