Granular Media Filter are used for clarification but can also be used for biological or chemical reaction, for adsorption or for mass transfer.
These operations may require special media such as calcium carbonate, dolomite, activated carbon or ions exchange resins.
Granular Media Filter can be static beds or moving beds. Static beds are cheaper but required intermittent regeneration when they are off-line. In moving beds the cleaning is continuous.
The most common material for granular media filter is sand, but gravel, anthracite, limestone, pumice and activated carbon are also commonly used.