filtermediet

Filtermediet, or filter medium, is the material that forms the barrier through which a fluid passes during filtration. It traps solids, excludes particles, or adsorbs contaminants, enabling separation of phases in processes such as water treatment, air purification, and laboratory analysis. Filtermedier can be broadly categorized into depth filters, surface filters (membranes), and adsorption or ion-exchange media. Depth filters, such as sand, anthracite, cellulose, diatomaceous earth, and ceramic media, rely on a porous matrix that enlarges the path length and captures particles throughout the depth of the medium. Surface filters, including polymeric membranes and glass fiber sheets, provide a relatively uniform pore structure and retain particles on or near the surface. Adsorption media, such as activated carbon and zeolites, remove contaminants by chemical attraction rather than physical occlusion. In air filtration, filtermediet also includes HEPA and other high-efficiency media, designed to capture particulates at high efficiency.

When selecting a filtermedium, factors include pore size or rating, porosity, permeability, chemical compatibility with the fluid, temperature tolerance, mechanical strength, fouling propensity, and cost and availability. The intended application determines whether a depth, surface, or adsorption medium is appropriate, as well as required maintenance routines.

Maintenance involves periodic inspection, cleaning or replacement, and proper disposal of spent media, which may be hazardous depending on captured contaminants. Filtermedier are widely used in municipal water treatment, industrial processing, beverage production, pharmaceuticals, and HVAC systems.