Filterung

Filterung is the process of separating solids from liquids or purifying a substance by allowing selectively permeable barriers to pass only desired components. In German, the noun is formed from the verb filtern (to filter) with the suffix -ung, and the term extends to many domains where a selective barrier or process is used. The English equivalents are filtration and filtering, but Filterung is commonly used in German-language texts.

In chemistry, environmental engineering and related fields, Filterung describes physical separation by porous media or membranes. Techniques include gravity or suction filtration and membrane-based methods such as microfiltration, ultrafiltration, nanofiltration and reverse osmosis. These methods differ in pore size and driving force, and they are used to remove suspended solids, microbes, or dissolved substances, often as a preprocessing step before analysis or further treatment.

In signal processing and data analysis, Filterung denotes the removal of undesired components from a signal or dataset. Digital filtering uses algorithms to suppress noise and artifacts while preserving signals of interest. Common examples are low-pass, high-pass, band-pass and notch filters, implemented as finite impulse response or infinite impulse response systems, and applied to audio, image, and sensor data.

Applications span water and air purification, food and beverage clarification, laboratory sample preparation, and medical contexts such as filtration of liquids or selective separation of biomolecules. Filterung choices affect efficiency, selectivity, fouling, temperature and chemical compatibility, and must balance cost, throughput and safety. The concept overlaps with but is not identical to English "filtration" and "filtering" depending on discipline.