Ultrasonic Atomization
Ultrasonics are capable of atomizing water droplets, and in theory could atomize bacteria, which contain, or are contained in water. Viruses, which are either contained within droplets of water or have organic components such as DNA, RNA or proteins, should also be atomizable. There are two methods by which this may be accomplished, supersonic nozzles and sonic generators.
If the airstream is forced through a supersonic nozzle, a standing shock wave develops at the nozzle outlet. This shock wave dissipates energy by imparting it to the airstream, causing it to expand suddenly and rapidly. This results in the atomization, or reduction to gas, of all bioaerosols in the airstream. The fan power or pumping power required to accomplish this however, would be considerable.
The use of a sonic generator to create the standing shock wave has the advantage of being much more efficient, as they are purely electronic. The sonic generator, essentially a high-power speaker and amplifier, tuned to resonate within the ductwork cavity, would create a standing shock wave through which the airstream would pass, and in which atomization of any bioaerosols would occur. Both this and the supersonic nozzle system would require a sound insulated ductwork section with inlet and outlet silencers.