Air Pollution Control Techniques For Livestock Farms

The polluted air in livestock farms associated with the epidemic disease outbreak and the environment problems. The objective of this study is to control the inlet and outlet air contaminants by removing the suspending particles. Based on the theoretical analysis, this paper designed the positive pressure ventilation systems with medium filters and the biomass dust-break wall to control inlet and outlet air pollution, respectively. The air contaminants make adverse effect on animals, especially for the newborns. So positive pressure ventilation systems with medium filters were installed in a full size Chicky occupied with about 12000 chicks to improve the inlet air quality. The ventilation rate was 54660m3/h which is based on maximum ventilation requirement of 3 - 4 m3/h per chick. The efficiency filter area was 61.6 m. The medium filter can remove 75% of TSP, 30% ofPMlO and 90% of Microbes suspending in the inlet air, respectively. After filtration, inlet air quality reached clean air standards. Compared with standard growth index, the gain in weight is increased by 2.5% - 25.5%, equality is increased by 4% ?20%, and mortality is reduced by 1%. In addition, it seems that the females could get more benefit than males from the same filtration system. A biomass dust-break wall filled with straw is designed to control the dust and odor emission from tunnel ventilated layer housing. A 17 metre x 3 metre x 0.5 metre sized dust-break wall was placed 4.8 m downwind of the exhaust-fan of a 3 level cage layers. The results of field experiment show that dust-break wall makes a good control for particles, microbe and odor emission. At lOin downwind to the exhaust-fan (about 4.7m downwind to the windbreak wall), TSP, PMIO, total microbes and colibacillus concentrations are reduced by 77%. 55%, 88% and 85% respectively. Odor concentration is reduced by a half. After biomass dust-break wall treatment, the heavily polluted exhaust air quality is improved to normal airstandard. The results show that dust-break wall greatly reduces the wind speed atl0m downwind to the exhaust-fan, and makes little effect on the ventilation systemof the layer housing.