In this paper we present and justify an original use of a diffusive-advective partial differential equation model, its discretization procedures and resulting numerical simulations for the dispersal of pollutants in an air-water system, with distinct behaviours in water and in air. The authors believe that the relevance of the developed work lies in its potential use in practical environmental assessment processes for the definition of both preventive and clean-up strategies. (c) 2006 Elsevier B.V. All rights reserved..20041732360370