filtrointi

Filtrointi (filtration) is the process of removing suspended solids and impurities from liquids or gases by passing the mixture through a porous barrier, medium, or membrane. The goal is to produce a clearer product, protect equipment, prevent contamination, and meet regulatory or quality standards. Filtration can be applied at various scales, from household water pitchers to industrial processing lines.

Filtration methods differ in mechanism and media. Mechanical or depth filtration uses a porous material to trap particles as the fluid travels through the medium. Surface filtration relies on a layer or membrane that captures particles at the surface. Filter media include sand, cloth, paper, activated carbon, diatomaceous earth, and synthetic materials. Filtration is often described by pore size or rating, such as coarse, fine, or micro- to nano-scale filtration.

Membrane filtration is a prominent modern approach, using selective barriers to separate particles by size. Common categories are microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and, in some contexts, reverse osmosis (RO) for nearly complete salt removal. Membranes can be polymeric or ceramic and may operate by pressure-driven processes or centrifugal forces.

Applications span water and wastewater treatment, food and beverage production, pharmaceuticals, oil and gas, electronics, and air handling systems. In process industries, filtration protects downstream equipment and ensures product quality, while in everyday life it enables safe drinking water, breathable air, and clearer beverages. Maintenance involves selecting appropriate media, monitoring pressure drop, backwashing where applicable, and replacing or regenerating filters to control fouling and maintain performance.