Water softener

Description

Chemical compounds or physical sorbents used to reduce the solid mineral content of hard water. Hard water is primarily due to salts of calcium and magnesium and it can form scale on pipes or react with soaps to form scum. Water softeners either precipitate (lime, soda) or chemically alter these compounds (ion exchange resins, trisodium phosphate). Cation exchange resins made from natural and artificial zeolites replace calcium and magnesium ions with sodium. Acid ion exchange columns replace the cation with a hydrogen ion while alkaline exchange columns replace the anion with a hydroxyl group. Both the acid and the alkaline exchange columns alter the pH of the resulting water.

Synonyms and Related Terms

plastifiant-réducteur d'eau (Fr.)

Authority

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 861

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

• Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997

• Encyclopedia Britannica, http://www.britannica.com Comment: "Water Softener." Encyclopædia Britannica. 3 Sept. 2004 .

• Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000