Experimental Evaluation of Sand Filtration Theory

An experimental evaluation of sand filtration theory is presented. The mathematical model of filtration presented by K. J. Ives (University College, London) was evaluated by the filtration of iron-bearing water. The results indicate that the equation does not adequately describe the filtration of water containing hydrous ferric oxide floc. Several minor modifications of Ive's equation were attempted without arriving at a suitable equation to fit the experimental data. Reasons for the inconsistency are presented. The iron floc does not conform to the characteristics assumed in the derivation of the equation, e.g., it is not of uniform size and it has a low density. Furthermore the use of the equation hinges on the determination of the specific deposit, namely, the volume of suspended solids removed per unit filter volume. This determination is so difficult as to greatly restrict the potential application of the equation.