GC: n
S: Puretec – https://puretecwater.com/resources/the-basics-of-reverse-osmosis/ (last access: 22 February 2025); PureAqua – https://pureaqua.com/what-is-reverse-osmosis-ro/ (last access: 22 February 2025).
N: 1. – reverse (adj): c. 1300, “opposite, contrary in position or direction, turned backward,” from Old French revers “reverse, cross, opposite” (13c.) and directly from Latin reversus, past participle of revertere “turn back, turn about, come back, return” (see revert). In reference to a gear mechanism enabling a vehicle to go backward without changing the rotation of the engine, by 1875. Reverse angle (shot, etc.) in film-making is from 1934. Reverse discrimination is attested from 1962, American English. Reverse dictionary, one in which the words are arranged alphabetically by last letter to first, is by 1954.
– osmosis (n): “the tendency of fluids to pass through porous partitions and mix with each other; the diffusion of fluids through membranes,” 1867, Latinized from osmose (1854), a shortened form of endosmose “inward passage of a fluid through a porous septum” (1829), from endo– “inward,” which is from Greek (see endo-) + Greek ōsmos “a thrusting, a pushing,” from stem of ōthein “to push, to thrust,” from PIE *wedhe- “to push, strike” (source also of Sanskrit vadhati “pushes, strikes, destroys,” Avestan vadaya- “to repulse”). Figurative sense is from 1900. Related: Osmotic (1854, from earlier endosmotic); osmotically.
2. reverse osmosis, separation technique in which pressure applied to a solution forces the solvent through a semipermeable membrane from a region of low concentration to one of high concentration, leaving behind the solutes. The membrane allows passage of small solution components, such as fresh water, while preventing passage of larger molecules, like salts and other impurities.
While osmosis naturally moves solvents across a membrane from the side of higher concentration to the side where the concentration is lower, the application of pressure in reverse osmosis forces the solvent to flow in the opposite direction—against the concentration gradient—thus resulting in the filtration of the solute from the solvent.
Reverse osmosis is an effective means of concentrating impurities, recovering contaminated solvents, cleaning up polluted streams, and desalinizing seawater and is often used as an alternative to distillation for water purification. Reverse osmosis can also be utilized in certain instances to perform separations prior to a chemical assay.
3. Chemistry; Water Treatment (Water Supply); Dust Removal; Fluid Mechanics and Hydraulics (Physics): reverse osmosis, RO.
- The flow of water through a membrane from a more concentrated to a less concentrated solution as a result of application of pressure to the former in excess of the osmotic pressure difference between the two.
- … reverse osmosis can be used to demineralise a saline solution and to remove pollutants from a polluted solution.
- reverse osmosis: term and definition standardized by ISO.
4. Chemistry; Food Industries; Biological Sciences: reverse osmosis, RO, hyperfiltration, HF
- A differentiation was made between the related membrane processes of reverse osmosis (RO) and ultrafiltration (UF). In RO, practically all molecular species except water are retained inside the membrane. This process is associated with small pore or ‘tight’ membranes and high hydrostatic pressures (500 p.s.i.).
- “Inverse osmosis” was carried over from a previous record: its occurrence has not been confirmed.
- There is considerable confusion in the open literature as to the distinction between microfiltration (MF), ultrafiltration (UF), and reverse osmosis (RO). For example, ultrafiltration has been referred to as both microfiltration and reverse osmosis.
N: 1. Etymonline – https://www.etymonline.com/search?q=reverse+osmosis (last access: 22 February 2025). 2. EncBrit – https://www.britannica.com/science/reverse-osmosis (last access: 22 February 2025). 3 & 4. TERMIUM PLUS – https://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&i=1&srchtxt=REVERSE+OSMOSIS&index=alt&codom2nd_wet=1#resultrecs (last access: 22 February 2025).
SYN:
S:
CR: desalination, electrodialysis, electrolysis, osmosis, salinity gradient energy, tap water.
