Modelling of Far-Field Mixing of Industrial Effluent Plume in Ambient Receiving Water: The Ikpoba River Hub Example
A study was initiated with a view to understanding the mathematical physics of industrial effluent plume dispersion in Ikpoba River which has resulted in the development of a sacrificial stretch along the river course and which made water body from that stretch unfit for various uses on account of resulting water quality parameters that are above threshold values. This study sought to describe the dynamics of advective and dispersive transport of the effluent plume in the river and also ascertain the extent of its effect from discharge location to downstream far-field region. A homogenous differential equation was used as analytics to describe the physical process that describes the wave of dispersion in water as a Doppler shift run. The model developed provides a geometric illustration of the dispersion process which gives a graphic detail of wavefronts distribution of effluent matter. Another important result of this study is that in the initially 3-D mixing process, the drop-off of the maximum mass concentration is relatively fast but thereafter the concentration gradually loses intensity downstream and at 1800m the concentration variations become below the water quality threshold criteria. In effect, industrial effluent loading is continuous and concentrated thereby causing a stretch of 1.8km sacrificial region to develop along the river course.