规模化猪场机械通风水冲粪式栏舍夏季氨日排放特征

Daily emission characteristics of ammonia from typical industrial pig farm with manure cleaning by rising water in summer

选取长三角地区典型机械通风水冲粪模式养猪场,针对不同生长阶段的肥猪栏舍和不同类型的母猪栏舍排放口氨排放进行同时监测(其中,育肥猪按质量分保育(<24 kg)、育肥-Ⅰ(24~60 kg)、育肥-Ⅱ(60~120 kg)3个阶段,母猪分为妊娠猪与分娩猪2种类型),估算各栏舍氨排放通量,分析各栏舍氨排放特征,探讨各生长阶段对氨排放贡献。研究结果表明,保育、育肥-Ⅰ、育肥-Ⅱ、妊娠、分娩栏舍氨质量浓度分别为(0.97±0.40)、(3.37±0.70)、(5.45±2.30)、(2.19±1.06)、(1.44±0.48)mg/m3;各栏舍氨排放具有显著的日变化过程,早晨氨排放呈波动增大趋势,午后开始降低,至夜间保持低值排放;小时氨排放速率与温度呈极显著正相关,与湿度呈显著负相关;各生长阶段氨排放存在差异,保育、育肥-Ⅰ、育肥-Ⅱ、妊娠、分娩栏舍日排放速率分别为0.85、6.53、8.20、10.39和13.86 g/(头·d);保育、育肥-Ⅰ和育肥-Ⅱ阶段对肥猪氨排放的贡献率分别为3.64%、26.11%和70.25%,妊娠猪与分娩猪对母猪氨的贡献率分别为75.32%和24.68%,母猪的氨排放速率是肥猪的1.87倍。

Ammonia（NH3）, as the only reactive alkaline gas, plays a crucial role in the neutralization of atmospheric sulfuric or nitric acid to generate ammonium salts, thereby affecting the acidity of cloud water and aerosols. At present, the ammonia emissions which is the main component of fine particulate（particulate matter equal to or less than 2.5 μm in aerodynamic diameter; PM2.5）, has become a global hot issue. Livestock and poultry breeding is the main emission source of ammonia, and the total amount of ammonia released by China＇s pig industry is much higher than that of Europe and North America. An in-depth study about ammonia emission from livestock sources may help policy-makers to develop emission reduction scheme and ease the haze. Generally, pig is considered to be the major contributor to ammonia emission. Therefore, in this study, we investigated NH3 emissions from a pig farm in Yangtze River delta region which were equipped with typical mechanical ventilation system and manure collection system cleaning by rising water. It monitored the ammonia emissions from different houses at the same time which included different growth stages of the fattening pigs and sows（among them, the fattening pigs can be divided in three phases according to the weight, Nursery（24 kg）, and Fattening-I（24-60 kg） and Fattening-Ⅱ（60-120 kg）.The sow can be divided into Gestation and Farrowing, and the ammonia emission flux was determined. Meanwhile, in this study, we analyzed the ammonia emission characteristics to explore the contribution of ammonia emissions in different growth stage. The results showed that the NH3 concentrations of Nursery, Fattening-Ⅰ, Fattening-Ⅱ, Gestation and Farrowing were（0.97±0.4）,（3.37±0.70） and（5.45±2.30）,（2.19±1.06） and（1.44±0.48） mg/m3, respectively. The ammonia emission in each column had a significant daily change process. In the morning, the ammonia discharge were fluctuated and increased, then started to decrease in the afternoon, and the value kept low at night. The ammonia emission rate was significantly positively correlated with the temperature and was negatively correlated with the humidity. The daily NH3 emissions rate of Nursery, Fattening-Ⅰ, Fattening-Ⅱ, Gestation and Farrowing were 0.85, 6.53, 8.20, 10.39 and 13.86 g/（pig·d）. In fattening pigs, the contribution rate of Nursery, Fattening-Ⅰ, Fattening-Ⅱwere 3.64%, 26.11% and 70.25%. In sows, the contribution rate of Gestation and Farrowing was 75.32% and 24.68%. Artificial disturbance, such as feeding and defecation, increased the ammonia emission in the pig houses. The ammonia emission rate of sows was 1.87 times higher than fattening pigs. By monitoring the concentration of ammonia emission from fattened pigs and sows at different growth stages, we explored the characteristics of ammonia emission from large-scale pig farms, discriminated and analyzed the important influencing factors of ammonia emission, and discussed the contribution of fattened pigs and sows of different types to ammonia emission during growth stages to provide technical support for the accounting of ammonia emission in regional livestock and poultry breeding. These findings in this paper could be useful for estimation of ammonia emissions accurately and implementation of ammonia emission reduction measures in China.