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The
passage of one substance into or through
another; e.g., an operation in which
one or more soluble components of a
gas mixture are dissolved in a liquid. |
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Acclimatization
: |
The
physiological and behavioral adjustments
of an organism to changes in its environment. |
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ACID
: |
A
substance which releases hydrogen ions
when dissolved in water. Most acids
will dissolve the common metals, and
will react with a base to form a neutral
salt and water. |
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Acid
Deposition/Acid Rain : |
A
complex chemical and atmospheric phenomenon
that occurs when emissions of sulfur
and nitrogen compounds and other substances
are transformed by chemical processes
in the atmosphere, often far from the
original sources, and then deposited
on earth in either a wet or dry form.
The wet forms, popularly called "acid
rain," can fall as rain, snow,
or fog. The dry forms are acidic gases
or particulates. |
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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 adsorbent for organic matter and
certain dissolved gases. Sometimes called
"activated charcoal". |
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Adhesion
: |
Molecular
attraction which holds the surfaces
of two substances in contact. |
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ADSORBENT
: |
The
process in which matter adheres to the
surface of an adsorbent. |
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Adsorption
: |
1.
Adhesion of molecules of gas, liquid,
or dissolved solids to a surface. |
2.
An advanced method of treating wastes
in which activated carbon removes organic
matter from wastewater. |
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Advanced
Waste Water Treatment : |
Any
treatment of sewage that goes beyond
the secondary or biological water treatment
stage and includes the removal of nutrients
such as phosphorus and nitrogen and
a high percentage of suspended solids.
(See primary, secondary treatment.) |
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Aeration
Tank : |
A
chamber used to inject air into water. |
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Aeration
: |
A
process which promotes biological degradation
of organic water. The process may be
passive (as when waste is exposed to
air), or active (as when a mixing or
bubbling device introduces the air). |
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Agglomeration
: |
The
process by which precipitation particles
grow larger by collision or contact
with cloud particles or other precipitation
particles. |
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Algae
: |
Simple
rootless plants that grow in sunlit
waters in relative proportion to the
amounts of nutrients available. They
can affect water quality adversely by
lowering the dissolved oxygen in the
water. They are food for fish and small
aquatic animals. |
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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. |
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Anaerobic
: |
A
life or process that occurs in, or is
not destroyed by, the absence of oxygen. |
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ANION
: |
A
negatively charged ion in solution,
such as bicarbonate, chloride or sulfate. |
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ANION
EXCHANGE : |
An
ion exchange process in which anions
in solution are exchanged for other
anions from an ion exchanger. In demineralization,
for example, bicarbonate, chloride and
sulfate anions are removed from solution
in exchange for a chemically equivalent
number of hydroxide anions from the
anion exchange resin. |
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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. |
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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, to waste. |
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Bacteria
: |
(Singular:
bacterium) Microscopic living organisms
which can aid in pollution control by
consuming or breaking down organic matter
in sewage. or by similarly acting on
oil spills or other water pollutants.
Bacteria in soil, water or air can also
cause human, animal and plant health
problems. |
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Baghouse
Filter : |
Large
fabric bag, usually made of glass fibers,
used to eliminate intermediate and large
(greater than 20 microns in diameter)
particles. This device operates in a
way similar to the bag of an electric
vacuum cleaner, passing the air and
smaller particulate matter, while entrapping
the larger particulates. |
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Bar
Screen : |
In
wastewater treatment, a device used
to remove large solids. |
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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. |
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BED
: |
The
exchange or filter media in a column
or other tank or operational vessel. |
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BED
DEPTH : |
The
height of the ion exchange or filter
media in the vessel after preparation
for service. |
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Biochemical
Oxygen Demand (BOD) : |
A
measure of the amount of oxygen consumed
in the biological processes that break
down organic matter in water. The greater
the BOD, the greater the degree of pollution. |
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Biodegradable
: |
The
ability to break down or decompose rapidly
under natural conditions and processes. |
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Biological
Control : |
In
pest control, the use of animals and
organisms that eat or otherwise kill
or out-compete pests. |
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Brackish
Water : |
A
mixture of fresh and salt water. |
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BRINE
: |
A
strong solution of salt (s), such as
the sodium chloride brine 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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