| Animal production activities were carried out in the barns in modern scaled poultry and livestock farms. The daily managements and animal activities would influence the air and the health of the people and animals in the barns, therefore, the aerosols related research in livestock and poultry farms were getting more and more attention. During October 2014 and August 2015, measurement points were set inside and outside three fattening pig barns, in suburb Beijing, the particulate matter concentrations of PM2.5, PM10 and TSP at the intake pots of the barns, the concentration of particulate matter, bacteria, Streptococcus and E. coli inside the barns and the particulate matter concentrations at the fans inside the barns were measured. In order to provide the scientific basis and reference data to design the aerosol mitigation methods in the livestock and poultry farms, the anniversary aerosol laws underlying data of the fattening pig barns were got, and the measurement of particulate matter discharged from the fattening pig barns was also completed, a method to reduce the aerosols in the fattening barns was introduced as well. The main results of this study were as follows.(1) The anniversary PM2.5 concentration outside the Fattening pig barns was 11~372 μg·m-3, PM10 was 25 ~ 444μg·m-3, TSP was 31 ~ 742μg·m-3. The anniversary PM2.5 concentration inside the Fattening pig barns was 23~245μg·m-3, PM10 was 113~1182μg·m-3, TSP was334~4396μg·m-3, representing each season PM10 TSP ratio above 60%. Particulate matter inside the barns mainly from feed and animal activity, the concentration of PM2.5 inside the pig barns were influenced strongly by the atmospheric environment.(2) There were small daily temperature fluctuations throughout the year in the fattening barns, the annual average temperature(was 22.1±3.31) ℃; relative humidity volatile. Particulate matter concentrations, two distinct peaks occurred around 09:00 am and 15:00 pm by fattening pig inside, there was a small peak around 02:00 in the morning. In the fattening pig barns, spring, summer, autumn and winter average concentrations of ammonia were(7.15 ±10.18)mg/m3,(4.82±4.27)mg/m3,(7.17±6.98) mg/m3 and(7.62±3.40) mg/m3.There was strongest correlation(r=0.651) between annual concentration of ammonia and PM10 in barns. The concentration rang of bacteria, Streptococcus and E. coli within the year was 2.85×104~8.61×104CFU/m3, 9×103~4.21×104 CFU/m3, 3×102~8.1×103CFU/m3, respectively, consistent with the law changes with the seasons, and were mainly dependent on the particle size of greater than 3.3μm particles. Piggery total number of bacteria in the air and PM2.5 concentration change positively correlated(r = 0.682),while a negative correlation with the TSP concentration change(r =-0.565). Changes in E. coli and PM10 and TSP concentrations were negatively correlated with r=- 0.583 and-0.751, respectively.(3) The average daily mass of the particulate matter discharged from the barns in spring was(1508±255)g/d, 2.67g/(d·pig) and the summer of(1149 ±51)g / d, 2.03g/(d·pig), autumn(1833±165)g / d, 3.24g/(d·pig), the winter of(1675±361)g/d, 2.96g/(d·pig), anniversary average daily emissions of(1350±1075)g/d. 2.39 g/(d·pig). Three pig fattening annual emissions of PM2.5 was 224 kg / year, PM10 was 474 kg / year, TSP was 1215 kg / year.(4) Based on the study results, an air cleaning system in the fattening pig barns was designed and made. |
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