A diffusion model of adsorption layer from asphalto-resinous substances on water drop surface is proposed and a formula for determining its thickness is given. A model of combined drop coalescence and disintegration in an isotropic turbulent flow is developed. Equations for determining evolution of the number of drops and their size with time, which depend on the frequency of disintegration and coalescence, are proposed. At low Weber numbers (We < 1) these models agree satisfactorily with the available experiment data.