Biocidal effectiveness of combustion products of reactive materials: A phenomenological model

Reactive materials (RMs) generating biocidal combustion products were developed for countering biological weapons of mass destruction. In experiments, aerosolized spores and bacteria simulating bio-agents are exposed to the RM combustion products. An inactivation factor (IF) defined as an inverse fraction of microorganisms surviving the exposure serves to compare different RMs. Such comparisons identify promising RMs, which generate highly biocidal combustion products. It is necessary to quantitatively characterize the biocidal effectiveness of these materials while modeling combustion of relevant RMs in practical configurations, such as an expanding fireball. The objective of this research effort is to develop a phenomenological model describing the efficiency of biocidal products generated by RMs. Here, we developed a hydrodynamic model of the experimental setup, which was previously built and utilized for testing various biocidal materials. This model is capable of predicting the field of temperatures and concentration of biocidal species (iodine) generated in combustion. The iodine generation was described accounting for the burn rates previously determined for the iodine-bearing RM particles. Trajectories for 100,000 microorganisms aerosolized into the flow system and exposed to the heated combustion products were determined. The exposure of each microorganism to both temperature and iodine concentration profiles was quantified by a model designed to correlate the predicted exposure levels with previously obtained experimental IF values.