Avskiljning

Avskiljning is a Swedish term for the act of separating a mixture into distinct components. It covers processes that exploit differences in physical properties such as phase, density, solubility, particle size, or chemical affinity to remove, recover, or purify substances. The concept is used across science, engineering and industry to describe both routine and specialized separation steps.

The range of avskiljning methods includes physical separation such as sedimentation and settling, filtration, decantation and centrifugation, as well as flotation to remove dispersed phases. Phase separation methods include distillation, crystallization, extraction and various membrane-based techniques (microfiltration, ultrafiltration, nanofiltration). Chemical and adsorption-based approaches, such as solvent extraction, ion exchange, and precipitation, also fall under avskiljning when they achieve separation of components.

In practical applications, avskiljning is central to wastewater treatment (clarifiers, thickeners, oil-water separators, dissolved air flotation), industrial processing and the production of chemicals, food, and pharmaceuticals. In the oil and gas industry, produced fluids are routed through a sequence of separators to obtain distinct oil, water, and gas streams. In general, separation steps are used to purify products, remove impurities, or concentrate desired components.

Key performance aspects include separation efficiency, yield, purity and selectivity, which depend on the properties of the substances involved and the chosen method, as well as operating conditions such as temperature, pressure, flow, and mixing. Etymologically, avskiljning derives from av- meaning away and skiljning from skilja, “to separate.”