Modeling of Aerosol Dispersion from a Busy Road in the Presence of Nanoparticle Fragmentation

Abstract A simple semianalytical model of dispersion of nanoparticle aerosols from a busy road in the presence of intensive particle fragmentation is developed. In particular, it is predicted that the total number concentration may be characterized by a significant maximum at an optimal distance from the road. Simple analytical existence conditions of such a maximum are derived. Applicability conditions for the model and the effect of turbulent diffusion and dry deposition of nanoparticles on the theoretical predictions are also discussed. As a result of the comparison of the theoretical predictions with the experimental results on the total number concentration as a function of distance from the road, the typical fragmentation rate coefficient has been determined as ≈0.086 s−1, with an estimated error of ∼30%.