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Back-Flow |
Flow of water in a pipe or
line in a direction opposite to normal flow. Often associated with back
siphonage or the flow of possibly contaminated water into a potable water
system. |
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Back-Flow Preventer |
A device or system
installed in a water line to stop back-flow. (See vacuum breaker, air
gap.) |
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Backwash |
The process in which beds
of filter or ion exchange media are subjected to flow opposite to the
service flow direction to loosen the bed and to flush suspended matter
collected during the service run. |
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Bacteria |
Unicellular prokaryotic
microorganisms which typically reproduce by cell division. |
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Base |
A substance which releases
hydroxyl ions when dissolved in water. Bases react with acids to form a
neutral salt and water. (See alkali.) |
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Base Exchange |
Synonymous with cation
exchange. |
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Batch |
A quantity of material
treated or produced as a unit. |
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Batch Operation |
A process method in which a
quantity of material is processed or treated usually with a single charge
of reactant in a single vessel, and often involving stirring. Example: The
neutralization of a specific volume of an acid with a base in a vessel,
with stirring or mixing, is a batch operation. |
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Bed |
The ion exchanger or filter
media in a column or other tank or operational vessel. |
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Bed Depth |
The height of the ion
exchanger or filter media in the vessel after preparation for service. |
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Bed Expansion |
The increase in the volume
of a bed of ion exchange or filter media during upflow operations, such as
backwashing, caused by lifting and separation of the media. Usually
expressed as the percent of increase of bed depth. |
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Best Available
Technology |
The water treatment(s) that
EPA certifies to be the most effective for removing a contaminant. |
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Bicarbonate Alkalinity |
The alkalinity of a water
due to the presence of bicarbonate ions (HCO3). |
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Biochemical Oxygen Demand
(Bod) |
The amount of oxygen
consumed in the oxidation of organic matter by biological action under
specific standard test conditions. Widely used as a measure of the
strength of sewage and waste water. |
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Biodegradable |
Subject to degradation to
simpler substances by biological action, such as the bacterial breakdown
of detergents, sewage wastes and other organic matter. |
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Bleach |
An oxidizing agent
formulated to break down colored matter. Includes the widely used
hypochlorites, as well as perborates and other special purpose materials. |
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Bod |
Abbreviation for
"Biochemical Oxygen Demand". |
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Brackish Water |
Water having salinity
values ranging from approximately 500 to 5,000 parts per million
(milligrams per liter). |
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Breakpoint Chlorination |
A chlorination procedure in
which chlorine is added until the chlorine demand is satisfied and a dip
(breakpoint) in the chlorine residual occurs. Further additions of
chlorine produce a chlorine residual proportional to the amount added. |
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Breakthrough |
The appearance in the
effluent from a water conditioner of the material being removed by the
conditioner, such as hardness in the effluent of a softener, or turbidity
in the effluent of a mechanical filter; an indication that regeneration,
backwashing, or other treatment is necessary for further service. |
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Brine |
A strong solution of salt(s),
such as sodium chloride used in the regeneration of ion exchange water
softeners, but also applied to the mixed sodium, calcium and magnesium
chloride waste solution from regeneration. |
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Buffer |
A chemical which causes a
solution to resist changes in pH, or to shift the pH to a specific value. |
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Builder |
A chemical incorporated in
a detergent formulation to produce a desired alkalinity level and improve
the ability to suspend soil. The alkaline phosphates are widely used for
this purpose. |
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Bypass |
A connection or a valve
system that allows untreated water to flow through a water system while a
water treatment unit is being regenerated, backwashed or serviced; also
applied to a special water line installed to provide untreated water to a
particular tap, such as a sill cock. |
Ace Hardware
