The objective of the paper is twofold: (i) to present a model (the so-called diffusion-inertia model) for predicting dispersion and deposition of aerosol particles in two-phase turbulent flows and (ii) to examine the performance of this model as applied to the flows in straight ducts and circular bends. The model predictions compare reasonable well with both experimental data and Lagrangian tracking simulations coupled with fluid DNS or LES. (C) 2009 Elsevier Ltd. All rights reserved.