Clogging of Rapid Sand Filters

Selected Operations Involving Transport of a Single Fluid Phase through a Porous Medium

“…The validity of Eq. (4.1.3) has been verified on numerous occasions (e.g., Cleasby and Baumann, 1962;Eliassen, 1941;Ling, 1955), at least at the beginning of filtration (Heertjes and Lerk, 1967;Ives, 1962). The reported values of mj range from about 30 into the hundreds, but most of the values lie between 30 and 80.…”

Filtration of water and wastewater

“…This was first observed experimentally by Eliassen. 58 To generate these curves mathematically it is necessary to solve the system of Equations 15,17, and 18. Explicit solutions have been attempted by most of the authors already mentioned, and a very useful review of the analytic integrations of such differential equations has been recently published by Herzig et al 66 In their analysis they proved the generality of the simple relationship of Equation 24:…”

Some Chemical Aspects of Rapid Sand Filtration

“…The abscissa is computed from the product of flow rate, filtration time, and applied iron concentration. 16 the exact mechanism by which these chemicals affect filtration." It is probable that their effects are influenced by the type and concentration of other dissolved ions in the water and also by the pH of the system, as these parameters affect the polyelectrolyte molecules, the surfaces of Jour.AWWA the suspended particles, and the filter medium.…”

“…It is concluded that the results obtained in the present research with fine sand grains compare favorably with the work of previous investigators, and that the surface properties of clean sand in the filter medium can vary with pH and the type and valence of the cations in the water. 16…”