Absorbent - The process in which matter adheres to the surface of an absorbant.
Acid - A substance which releases hydrogen ions when dissolved in water.Most acids will dissolves the common metals, and will react with a base to form a neutral salt and water.
Activated Carbon - A granular material usually produced by the roasting of cellulose base substances, such as wood or coconut shells, in the absence of air.It has a very porous structure and is used in water conditioning as an absorbent for organic matter and certain dissolved gases. sometimes called " activated charcoal ".
Alkalinity - The quantitative capacity of a water or water solution to neutralize an acid. It is usually measured by titration with a standard acid solution of sulfuric acid, and expressed in terms of its calcium carbonate equivalent.
Anion - A negatively charged ion in solution, such as bicarbonate, chloride, or sulfate.
Anion Exchange - An ion exchange process in which anions in solution are exchanged for other anions for an ion exchanger. In demineralization, for example, bicarbonate, chloride and sulfate anions are removed from solution in exchange for a chemically equivalent number hydroxide anions from the anion exchange resin.
Aquifier - A layer or zone below the surface of the earth which is capable of yielding a significant volume of water.
Atom - The smallest particle of an element that can exist either alone or in combination with similar particles of the same element or of a different element.
Attrition - The process in which solids are worn down or ground down by friction, often between particles of the same material. filter media and ion exchange materials are subject to attrition during backwashing, regeneration, and service.