DIFFUSIONAL MECHANISM OF SUBMICRON AEROSOL WASH-OUT

A comparison is performed of the "wind" factor obtained by a numerical solution of the equation of convective diffusion of the gas-aerosol admixture on spherical particles of the rough dispersal atmospheric aerosol with various asymptotics for small and large Pekle numbers. On the base of this comparison, a simple approximate equation is proposed which enables one to evaluate with appropriate precision the value of the "wind" factor in case of Brownian deposition of submicron particles of any size on rough dispersal aerosol particles of size ranging from some to several dozens of micrometers. Analysis is carried out of the dependence of the time of semideposition of the submicron particles on different characteristics of the rough dispersal aerosol spectrum. A simple approximate equation for its evaluation is proposed. It is found that the efficiency of washing-out of the particles with dimensions over 10(-3) mcm increases according to the parabolic law with growth of the mean size of the rough dispersal aerosol.