Pollutants Spread in a Bifurcating River: The River Nun, Bayelsa, Nigeria

Abstract

Pollutants have grievous impacts on human lives and aquatic ecosystem. Reducing them in our environment is a global objective that demands cooperation from all, and the services of experts. In view of this, a hydrodynamic model of the spread of pollutants in a bifurcating river is presented to investigate the role of the flow dynamics of rivers in the dispersion of pollutants. The study is centred on the River Nun, Bayelsa, Nigeria where there are incidences of pollution. The flow model is governed by a set of nonlinear and coupled partial differential equations, solved by the methods similarity transformation and perturbation series expansions. Expressions for the temperature, concentration and velocity are obtained and analyzed graphically. The analyses show that the bifurcation angle, Reynolds number and thermal differentials increase the velocity of the flow. These results have attendant implications on the spread of pollutants in the River Nun. In particular, if the deposition of pollutants in a location of the river is stopped, the increase in velocity will enhance the spread of the existing pollutants through the infinite river, thus reducing their concentration at that location to an allowable level, safe for man and the aquatic ecosystem.