Compact wet cyclone air sampler with enhanced collection efficiency

Air samplers are crucial to effectively capture bioaerosols in various environments. However, the current air samplers have limitations, including a large pressure drop due to their high inlet flow rate and low collection efficiency, and they lack a pre-separation and concentration system. Designing a new and efficient air sampler with an inlet flow rate of 10 L/min is of utmost importance. In this study, a wet cyclone air sampler (WCS) was designed consisting of a pre-separator, a uniflow cyclone separator, a water injector, and a recirculation system for the collection water. Recirculating the particle-laden water and reinjecting it into the cyclone body enhanced particle concentration within the collection bottle. Various particles such as Arizona dust, monodisperse silica particles, and bacillus subtilis endospores were aerosolized to evaluate the collection efficiency of the developed WCS. The pre-separator and the uniflow cyclone separator have cut-off diameters of 14 mu m and 0.93 mu m with an inlet air flow of 10 L/min. The collection efficiency of the WCS for bacillus subtilis endospore can reach 40.0 %, and extending the recirculation time to 20 minutes increases the collection efficiency further to 64.6 %.