Grain Size Distribution of the Self-Filtration Layer between the Base Soil and the Filter

Abstract

Some studies suggested a model to determine the grain size distribution GSD curve of the self-filtration layer that is formed at the base soil-filter interface. From these GSD curves the effectiveness of the filters is assessed assuming that the internal stability of the self-filtration layer reflects the effectiveness of the filter. In this paper a critical discussion to that method is presented. Also some essential modifications for the method are suggested. Finally, in disagreement with that method the applicability of usage of the GSD curve of the self-filtration layer to predict the effectiveness of the filter is found to be unreliable.