You are here:
TRAJECTORY OF AEROSOL DROPLETS FROM A SPRAYED BACTERIAL SUSPENSION
Citation:
Lighthart, B., B. Shaffer, B. Marthi, AND L. Ganio. TRAJECTORY OF AEROSOL DROPLETS FROM A SPRAYED BACTERIAL SUSPENSION. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-91/146 (NTIS PB91219048), 1991.
Description:
Simulated droplet trajectories of a polydispersed microbial aerosol in a laminar air flow regimen were compared with observed ispersal patterns of aerosolized Bacillus subtilis subsp. niger spores in quasilaminar airflow. imulated dispersal patterns could be explained in terms of initial droplet sizes and whether the droplets evaporated to residual aeroplanktonic size before settling to the ground. or droplets that evaporated prior to settling out, a vertical downwind size fractionation is predicted in which the microbial residue of the smallest droplets settles the least, and is found in the air-stream at about sprayer height, and progressively larger droplet residues settle to progressively lower heights. bservations of spore particle size distributions downwind from a spray source support the simulation. roplet and particle size distributions near the source had three size fractions: one containing large, presumably nonevaporated droplets of >7 in diameter, and two smaller fractions, with diameters of 2 to 3 um (probably the residue of droplets containing more than one spore) and 1 to 2 um (probably the residue from single spore droplets). s predicted by the simulation, the aerosol settled and progressed downwind, with the number of small droplets and particles increasing in proportion to the height and distance downwind.