Transport of pollutants in natural streams
A modified two-dimensional mathematical model has been developed to simulate the dispersion of soluble degradable and nondegradable pollutants discharged from multiple industrial outfalls along a large river. This model takes into account the effects of depth and velocity variations in both longitudinal and lateral directions, the removal rates of degradable organic trace pollutants, the lateral convection of mass, and the effect of jet mixing and dilution at the outfalls. It can also accommodate the rapid convergence or divergence in stream width and the influence of an island and of flow diversion on pollutant dispersion.The model was validated by using phenol as a pollutant and comparing the computed values with the field data collected by the Ontario Ministry of the Environment. The application of this model to the simulation of organic pollutant levels in the St. Clair River due to discharges from multiple sources is demonstrated in this paper. Keywords: degradable pollutants, dispersion; jet mixing, pollutant transport, multiple outfalls, nondegradable pollutants, St. Clair River.