Effectiveness of an air cleaner device in reducing aerosol numbers and airborne bacteria from an enclosed type dairy barn

Abstract

There is growing pressure to find technically feasible and economically viable solutions in reducing emissions of pollutants from various occupational settings to minimise environmental pollution. Hence, it is essential to develop and test methods for controlling pollutants from occupational backgrounds. We have tested an air cleaner device in reducing aerosol numbers by filtration and airborne bacteria by photocatalysis from an enclosed type dairy barn. Here, we had shown a significant reduction of larger size aerosol numbers (2.0-10.0 µm) and airborne total aerobic bacteria and Staphylococcus aureus (S. aureus) and complete clearance of Escherichia coli (E. coli) in the exhaust air of the air cleaner device. A greater 8.05% and 61.56% reduction of 5.0-10.0 µm aerosol numbers and airborne E. coli, respectively, were observed in the instantly treated central air of the dairy barn. We had found an increasing trend of aerosol numbers and airborne bacteria concentrations in the central air of the dairy barn after stopping the air cleaner device. We also had observed increased bacterial load in the filter paper of the air treatment chamber of the air cleaner device with the advancement of cleaning time. These findings are essential to validate air cleanings from various types of dairy microenvironments.

Keywords: Aerosol numbers; Air cleaning; Airborne bacteria; Dairy barn; Filtration; Photocatalysis.