Designing of bioaerosol production system for removing Escherichia coli from contaminated air using bone char

Bacterial agents are among the most important sources of infection transmission in hospital wards. Thereby, designing of a bio-aerosol convertor for investigation of biological agents in air is necessary. The aim of this study was designing of a suitable system for bio-aerosol production and elimination of Escherichia coli from contaminated air using bone char. This applied research was performed during 8 months. Bone char was prepared by electrical furnace. Bone char was crushed and pulverized with a range of 20- 60 mesh. The absorptive characteristics of Bone char was determined using X-ray diffraction technique. The pHzpc and specific surface area were determined via titration and N2 gas adsorption according to BET absorption isotherm method. The bacterial aerosol with concentrations of 103-107 CFU per ml of airflow were prepared by a nebulizer and injected to the system. 7th version of RSM software was used for data analysis. E. coli removal efficiency had a linear correlation with adsorbent weight as 103 CFU/ml initial bacterial concentrations and with 4, 7 and 10 g adsorbent mass reached to 30, 20 and 15 CFU/ml, respectively. In addition, the adsorbent pore size in the range of 20-40 mesh was more efficient in bacterial removing in comparison with mesh particles >40. Efficiency of the contaminant air purification achieved 99.99% with the 20-40 mesh adsorbent at 30 minutes. The designed system for production of bio-aerosol has good performance in the study of Escherichia coli removal from contaminated air using bone char.