Decantation is frequently used to purify a liquid by separating it from a suspension of insoluble particles (e.g. in red wine, where the wine is decanted from the potassium bitartrate crystals to avoid unsavory taste). This makes the wine more tonic and astringent.
Cream accelerates to the top of milk, allowing the separation of milk and cream. This is used in the cheese industry. Fat is determined in butter by decantation.
To obtain a sample of clear water from muddy water, muddy water is poured into another container, which separates the water from the mud.
In the sugar industry, the processing of sugar beets into granular sugar involves many liquid–solid separations; e.g. separation of syrups from crystals.
Decantation is also present in nanotechnology. In the synthesis of high quality silver nanowire (AgNW) solutions and fabrication process of high performance electrodes, decantation is also being applied which greatly simplifies the purification process.
After using a desiccant to absorb water from an organic liquid, the organic liquid can often be decanted away from the desiccant.
The process of deriving vinegar also requires decantation to remove fats and biomolecular antioxidants from the raw substance. 
Plasma can be separated from blood through decantation by using a centrifuge.
Mercury is disposed of in water bodies during mining, turning the water unfit and toxic. The mercury can be removed through decantation.