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

  Aims: 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.   Methods: 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.   Results: 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. Conclusion: The designed system for production of bio-aerosol has good performance in the study of Escherichia coli removal from contaminated air using bone char.