Deterministic particle tracking simulation of pollutant discharges in rivers and estuaries

A two-dimensional deterministic particle tracking model, in which the anisotropic-dispersive process is described by a particle strength exchange scheme, is established for the simulation of pollutant transport in vertically well-mixed rivers and estuaries. By simulating two benchmark problems with analytic solutions, the PSE scheme is shown to be accurate even if the anisotropic ratio of dispersion coefficients is very high. Further simulations of two specific problems concerning the optimal effluent discharge location and procedure are presented. The major conclusion is that in a tidal estuary with a relatively large fresh-water flow, setting the discharge position at the mixing center and making the discharge rate proportional to flow speed may minimize the peaks of concentration.