Ultrafiltrations

Part of speech: noun

Definitions

1. A process involving the filtration of liquids through a membrane that removes particles larger than a certain size while allowing smaller molecules to pass through
2. A technique used in water treatment and chemical processing to separate contaminants from solvents by utilizing a selective barrier
3. The act of separating substances in a fluid by passing it through a porous medium that retains larger particles, facilitating purification or concentration

Etymology: The word's second half is the older and more interesting piece. "Filtration" came into English from French "filtration", which was built on "filtrer", meaning to strain liquid through a porous material, and "filtre", the filter itself. That French "filtre" was borrowed from Medieval Latin "filtrum", a term for felt, the dense woollen cloth that was used to strain liquids. So the idea of filtering began with a piece of fabric: the felt that caught the sediment. The prefix "ultra-" comes straight from Latin "ultra", meaning "beyond". Attached to "filtration", it names a finer process, one that pushes liquid through membranes with pores so small they hold back dissolved particles and large molecules that ordinary filters let through. Plural "ultrafiltrations" is simply the countable form of "ultrafiltration", used when referring to several separate procedures or runs of the process.