Rapid Sand Filter - Granular Media Bed Design, Enhanced Mechanical Straining And Physical Adsorption For Effective Water Treatment

Rapid sand filtration is the flow of water through a bed of granular media, normally following settling basins in conventional water treatment trains. The purpose of this filtration is to remove any particulate matter left over after flocculation and settling. The filter process operates based on two principles, mechanical straining and physical adsorption. Sand filtration is a "physical-chemical process for separating suspended and colloidal impurities from water by passage through a bed of granular material. Water fills the pores of the filter medium, and the impurities are adsorbed on the surface of the grains or trapped in the openings." The key to this process is the relative grain size of the filter medium.

In case of Activated Carbon Filter, Activated Carbon is filled in the tank and the fluid to be treated is allowed to pass through the filter and due to adsorption the colour of the fluid will be removed.