Statistical Evaluation of Reaeration Prediction Equations

The object of much of the experimentation in atmospheric reaeration of natural streams is to develop models for predicting the reaeration coefficient, k₂. These prediction equations are statistical correlations of the hydraulic variables and fluid properties thought to be important in affecting k₂. Two previously reported models for predicting k₂ are reevaluated in the light of these criteria. Although the models are useful for estimating k₂, they do not adequately describe the variation in the observed data because their prediction error is significantly larger than the experimental error. Finally, two statistical models are used to predict k₂ from data from a third, independent source. The prediction error varied between a factor of 2 - 3 about the predicted value. Comparison with values predicted by a model founded in the penetration theory for gas absorption was favorable. This suggests that theoretical models hold more promise than empirical correlations as a source for equations to predict k₂.