AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Characterisation of a Rotating Drum for Bioaerosol Survival Studies
EMMA KEYSER, Carwyn Davies, Andrew Scott, Dstl
Abstract Number: 581 Working Group: Bioaerosols
Abstract The ability to study an aerosol in a suspended state can be beneficial when assessing the viability or variable factors on viability of a bacterial species over an extended period of time. This can be achieved by rotating a drum; rotational forces together with gravitational forces impart a circular path on the small particles within, which allows suspension for many hours.
Rotating drums can vary in size, volume and design and can have adjustable rotation speeds. As a consequence differing rotating drums may require individual experimental parameters, such as the time to ‘fill’ the drum to a certain concentration, and the time required to attain homogeneity of particles within the drum to achieve effective and reproducible sampling. These parameters can also be influenced and adapted to meet different experimental requirements.
Dstl has previously utilised in-house manufactured rotating drums, recently a new rotating drum was purchased of a different internal design.
A series of experiments were undertaken to provide information of the experimental parameters required for this individual drum and to compare its function to our in-house design.
These experiments were conducted using a 3-jet Collison to aerosolise Bacillus atrophaeus to produce dry 1-3 µm particles at varying humidities. The results enable investigations to choose ideal parameters to reliably meet specific experimental requirements, for example to adjust fill times and consequently be aware of how concentrated the bacterial aerosol suspension is immediately after filling. This work has also allowed direct functional comparison to differing drum designs.