A New Approach to the Biological Filtration Part I : The Mathematical Model

Abstract

In this paper an attempt has been made to set up a relationship between the removal efficiency and the hydraulic regimes of biological filters. For granu l ar-vmedi a trickl ing filters effluent concentrations have been calculated with the equation of complete mixing at low flow rates and by means of dispersed plug-flow model for large hydraulic loadings. Between the mixed flow and the dispersed flow regimes there is a transition zone. For coarse media with a specific surface area of 40 to 70 m'm-' the mixed flow zone disappears and the substrate removal is obtained using the equation of dispersed plug flow. The above mentioned flow I imits have been given as a function of the specific surface area of the media and the application of this theory to the practical problems has also been demonstrated.

A New Approach to the Biological Filtration Part Ii: Experimental Confirmation

“…2ITa 2ITa (7) It means that Eqs. 2 and 3 converts the cubical arrangement of spheres into a media consisting of vertical planes with a width B = 2ITa and with a hight L. The wetted perimeter of the media can also directly be found from Eq.…”