| |
Cadmium
(CD) : |
A
heavy metal element that accumulates
in the environment |
|
CALCIUM
: |
One
of the principal elements making up
the earth's crust, the compounds of
which when dissolved make the water
hard. The presence of calcium in water
is a factor contributing to the formation
of scale and insoluble soap curd which
are a means of clearly identifying hard
water. |
|
CAPACITY
: |
An
expression of the quantity of an undesirable
material which can be removed by a water
conditioner between cleaning regeneration
or replacement, as determined under
standard test conditions. For ion exchange
water softeners, the capacity is expressed
in grains of hardness removal between
successive regenerations and is related
to the pound of salt used in regeneration.
For filters, the capacity may be expressed
in the length of time or total gallons
delivered between servicing. |
|
Carbon
Adsorber : |
An
add-on control device which uses activated
carbon to absorb volatile organic compounds
from a gas stream. The VOCs are later
recovered from the carbon. |
|
CARBON
DIOXIDE : |
A
gas present in the atmosphere and formed
by the decay of organic matter; the
gas in carbonated beverages; in water
it forms carbonic acid. |
|
Carbon
Monoxide (C0) : |
A
colorless, odorless, poisonous gas produced
by incomplete fossil fuel combustion. |
|
Carcinogen
: |
Any
substance that can cause or contribute
to the production of cancer. |
|
Carcinogenic
: |
Cancer-producing. |
|
Cathodic
Protection : |
A
technique to prevent corrosion of a
metal surface by making that surface
the cathode of an electrochemical cell. |
|
CATION
: |
An
ion with a positive electrical charge,
such as calcium, magnesium and sodium. |
|
CATION
EXCHANGE : |
Ion
exchange process in which cations in
solution are exchanged for other cations
form and ion exchanger. |
|
CAUSTIC
: |
Any
substance capable of burning or destroying
animal flesh or tissue. |
|
Caustic
Soda : |
Sodium
hydroxide, a strong alkaline substance
used as the cleaning agent in some detergents. |
|
Cesium
(Cs) : |
A
silver-white, soft ductile element of
the alkali metal group that is the most
electropositive element known. Used
especially in photoelectric cells. |
|
CHELATE
: |
To
form a complex chemical compound in
which an ion, usually metallic, is bound
into a stable ring structure. |
|
Chemical
Oxygen Demand (COD) : |
A
measure of the oxygen required to oxidize
all compounds in water, both organic
and inorganic. |
|
Chemical
Treatment : |
Any
one of a variety of technologies that
use chemicals or a variety of chemical
processes to treat waste. |
|
Chlorination
: |
The
application of chlorine to drinking
water, sewage, or industrial waste to
disinfect or to oxidize undesirable
compounds. |
|
Chlorinator
: |
A
device that adds chlorine, in gas or
liquid form, to water or sewage to kill
infectious bacteria. |
|
CHLORINE
: |
A gas, C12, widely used in the disinfection
of water and an oxidizing agent for
organic matter, iron, etc. |
|
Chlorine-Contact
Chamber : |
That
part of a water treatment plant where
effluent is disinfected by chlorine. |
|
Chlorofluorocarbons
(CFCs) : |
A
family of inert, nontoxic, and easily
liquified chemicals used in refrigeration,
air conditioning, packaging, insulation,
or as solvents and aerosol propellants.
Because CFCs are not destroyed in the
lower atmosphere they drift into the
upper atmosphere where their chlorine
components destroy ozone. |
|
Clarification
: |
Clearing
action that occurs during wastewater
treatment when solids settle out. This
is often aided by centrifugal action
and chemically induced coagulation in
wastewater. |
|
Clarifier
: |
A
tank in which solids are settled to
the bottom and are subsequently removed
as sludge. |
|
COAGULANT
: |
A
material, such as alum, which will form
a gelatinous precipitate in water, and
cause the agglomeration of finely divided
particles into larger particles which
can then be removed by settling and
/ or filtration. |
|
Coagulation
: |
A
clumping of particles in wastewater
to settle out impurities. It is often
induced by chemicals, such as lime,
alum, and iron salts. |
|
Coliform
Index : |
A
rating of the purity of water based
on a count of fecal bacteria. |
|
Coliform
Organism : |
Microorganisms
found in the intestinal tract of humans
and animals. Their presence in water
indicates fecal pollution and potentially
dangerous bacterial contamination by
disease-causing microorganisms. |
|
CONDUCTANCE
: |
A
measure of the ability of a solution
to carry electricity; the reciprocal
of the electrical resistance. The unit
of conductance is the ohm (reciprocal
ohm). |
|
CONDUCTIVITY
: |
The
quality or power to carry electrical
current; in water, the conductivity
is related to the concentration of ions
capable of carrying electrical current. |
|
Coolant
: |
A
liquid or gas used to reduce the heat
generated by power production in nuclear
reactors, electric generators, various
industrial and mechanical processes,
and automobile engines. |
|
Cooling
Tower : |
A
structure that helps remove heat from
water used as a coolant; e.g., in electric
power generating plants. |
|
Corrosion
: |
The
dissolving and wearing away of metal
caused by a chemical reaction such as
between water and the pipes that the
water contacts, chemicals touching a
metal surface, or contact between two
metals. |
|
Cubic
Feet Per Minute (CFM) : |
A
measure of the volume of a substance
flowing through air within a fixed period
of time. With regard to indoor air,
refers to the amount of air, in cubic
feet, that is exchanged with indoor
air in a minute's time, or an air exchange
rate. |
|
CYCLE : |
A
series of events or steps which ultimately
lead back to the starting point, such
as the exhaustion- regeneration cycle
of an ion exchange system; sometimes
incorrectly used in reference to a single
step of a complete cycle. |
|
