Filtrats

Filtrats, or filtrates, are the liquid portion that has passed through a filter during a filtration process. When a mixture is filtered, solid material is retained on the filter as the residue, while the filtrate is the liquid that flows through. The composition of the filtrate depends on factors such as pore size, filter material, and the solubility and size of the suspended or dissolved components.

In scientific and technical literature, filtrate is the standard term in English; filtrats is used in some languages as the plural form. The process produces two stream outputs: the filtrate (the liquid) and the retentate or residue (the material left on or trapped by the filter). The relative content of dissolved substances in the filtrate is influenced by the filtration method, including gravity filtration, pressure filtration, and membrane filtration with defined pore sizes.

Applications of filtrates span analytical chemistry, biochemistry, and environmental engineering. In chemistry, filtrates are analyzed for ions, organic compounds, or contaminants. In biology and biochemistry, filtrates can contain enzymes, nutrients, or signaling molecules that pass through a membrane or filter. In water treatment, filtrates refer to the treated liquid after filtration stages.

Analysis and handling of filtrates may require further treatment, such as further filtration, concentration, or chemical analysis. The term helps distinguish the liquid product from the solid phase and is central to quantifying yields in purification and separation workflows.