Analytical modeling of three-stage inactivation of viruses within droplets and solid porous particles

Various viruses can hide within fluid and solid structures and thus successfully cross different distances, causing the spread of viral infections. Analytical modeling of the triple treatment of virus within a small liquid droplet and within a solid porous particle is the basic research polygon of this paper. The three-stage treatment aims to maximize the efficacy of deactivating viruses indoors. In order to achieve this, viruses undergo treatment by infrared heating, ultraviolet deactivation and ionization–electrostatic deactivation by negative ions. When the droplets are treated with infrared heating, incomplete evaporation occurs, reducing their initial diameter by 10 times; an initial diameter of droplets is 0.01 mm, 0.03 mm and 0.05 mm. Thermal inactivation of viruses inside the droplets is almost negligible, due to short exposure time and a maximum temperature of 100 °C. On the other hand, when solid porous particles are heated to a much higher temperature at the same exposure time, this causes significant thermal inactivation of viruses inside them. Reducing the diameter of the droplet (due to evaporation) by 10 times causes a multiple increase in UV-C deactivation of viruses inside the droplets. The effect of UV-C radiation on viruses within solid porous particles is not included in this paper. [Image: see text]