Theoretical Evaluation of Filter Modeling Experiments

Attempts to place the design and development of rapid sand filters on a more rational and rigorous basis have resulted in various mathematical models of the operation. A review of several of these models is presented. The model constructed by Ives is discussed in detail from the standpoint of present experimental methods employed in testing the efficacy of the model. Using data reported in the literature, it is shown that significant errors may be introduced when present analysis techniques are employed. Alternative data analysis methods are presented. Methods for establishing model parameter relationships within a single filter run are developed. The specific example used examines a method of relating λ to filtration rate by a series of step changes in rate within the same run.