Transport of bicomponent contaminant in free-surface wetland flow

This paper presents a theoretical analysis of a pulsed bicomponent contaminant emission into a free-surface wetland flow. The basic equations are for the bicomponent contaminant transport in the wetland flow under the combined action of advection, mass dispersion, and ecological reaction at the phase averaged scale. The effect of the ecological reaction is separated from the hydrodynamic effect via a set of widely used transforms. The analytical solution for the evolution of the depth-averaged concentration is rigorously derived, with a limiting case covering the known solution for the single component contaminant transport. It is found that the depth-averaged species concentration of the bicomponent contaminant can approach an equilibrium state determined by the distribution coefficient.