PREDICTION OF THE DISPERSION NUMBER IN WASTE STABILIZATION PONDS

A simple predictive equation for the dispersion number was derived from the solution of a second order steady state partial differential equation involving a diffusivity coefficient. This coefficient was evaluated as a function of aspect ratio with variable power and friction factor using multiple and linear regression analyses. The model was verified with dispersion data from the waste stabilization pond at Nsukka, Nigeria and from literature. It predicted values of the dispersion number closer to the experimental values than the Polprasert and Bhattarai model. The correlation coefficient, regressed slope, intercept and standard error of the former are 0.883, 0.361, 0.108 and 0.004, respectively, against 0.117, -0.227, 0.400 and 0.034 for the latter.