Model for settling and deposition of particulates emitted from an elevated source

Numerical solutions are obtained for gravitational settling and deposition velocities. The deposition of pollutants on ground surface is accounted for by including a gravitational settling term in transport equation and applying absorptive boundary condition at ground surface. A mixed finite difference scheme is used to solve the mathematical model considering advection, diffusion, settling and deposition. Wind velocity is approximated by a step function. Convergent approximation of wind profile provides compatibility with Eulerian grid spacing. Effect of gravitational settling velocity is quite prominent below the source. Due to its effect concentration increases considerably and it decreases above the source height. The effect of deposition is observed near the ground only. Deposition decreases concentration near the ground though there is no significant change in concentration of pollutant far from the ground.