Transient analysis of pollutant dispersion in a cylindrical pipe with a nonlinear waste discharge concentration

In this study we investigate the transient dispersion of a pollutant ejected by an external source into a laminar flow of an incompressible fluid in a cylindrical pipe. The Boussinesq assumption is applied and the nonlinear governing equations of momentum and pollutant concentration are obtained. The problem is solved numerically using a semi-implicit finite difference method. Solutions are presented in graphical form and given in terms of fluid velocity, pollutant concentration, skin friction and wall mass transfer rate for various parametric values. The model can be a useful tool for understanding the polluting situations of an improper discharge incident and evaluating the effects of decontaminating measures for the water body.