A deterministic model to predict the inertia-interceptional dust removal efficiency of open-space water spraying is developed based on momentum and mass balances of water droplets and dust particles. The effect of polydisperse dust particles and water droplets generated by different nozzles on the total removal efficiency (eta(total)) is examined. The small water droplets with narrower distribution could provide the acceptable removal of dust particles while the relatively large dust particles also provide the large eta(total) value. The eta(total) predicted by the developed model is in the range of 19.6-23.8% with a relative error of 2% when compared with the measuring data. The eta(total) with the use of polydispersity of water droplets and dust particles is more accurate than that with the use of average size of water droplets and dust particles. (C) 2011 Elsevier B.V. All rights reserved.