Filtermediums
Filtermediums, also known as filtration media, are materials used to separate solids or dissolved substances from a fluid by passing the fluid through them. They operate in depth filtration, where particles are captured throughout the bed, or surface filtration, where a layer forms at the surface.
Common granular media include silica sand, anthracite, garnet, and diatomaceous earth, used in layered beds for
Media properties—pore size and distribution, porosity, permeability, chemical compatibility, temperature and pressure limits, and fouling resistance—determine
Maintenance often includes backwashing for granular beds, chemical cleaning for certain media, and periodic replacement, with
Standards and guidelines from organizations such as NSF/ANSI specify suitability for drinking-water contact and performance testing.