| |
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Abbreviation
for "deionization". |
|
Dechlorination
: |
Removal
of chlorine from a substance by chemically
replacing it with hydrogen or hydroxide
ions in order to detoxify the substances
involved. |
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DEIONIZATION
: |
The
removal of all ionized minerals and
salts (both cationic and anionic) from
a solution by a two-phase ion exchange
procedure. First, positively charged
for a chemically equivalent amount of
hydrogen ions. Second, negatively charged
ions are removed by an anion exchange
resin for a chemically equivalent amount
of hydroxide ions. The hydrogen and
hydroxide ions introduced in this process
unite to form water molecules. The term
is often used interchangeably with demineralization. |
|
DEMINERALIZATION
: |
The
removal of ionized inorganic minerals
and salts (not organic materials) from
a solution by a two-phase ion exchange
procedure; similar to deionization,
and the two terms are often used interchangeably. |
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Denitrification
: |
The
anaerobic biological reduction of nitrate
nitrogen to nitrogen gas. |
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Desalinization
: |
Removing
salt from ocean or brackish water. |
|
Digester
: |
In
wastewater treatment, a closed tank;
in solid waste conversion, a unit in
which bacterial action is induced and
accelerated in order to break down organic
matter and establish the proper carbon
to nitrogen ratio. |
|
Digestion
: |
The
biochemical decomposition of organic
matter, resulting in partial gasification,
liquefaction, and mineralization of
pollutants. |
|
Disinfectant
: |
A
chemical or physical process that kills
pathogenic organisms in water. Chlorine
is often used to disinfect sewage treatment
effluent, water supplies, wells, and
swimming pools. |
|
DISINFECTION
: |
A
process in which pathogenic (disease
producing bacteria) are killed; may
involve disinfecting agents such as
chlorine, or physical processes such
as heating. |
|
Dispersant
: |
A
chemical agent used to break up concentrations
of organic material such as spilled
oil. |
|
Disposal
: |
Final
placement or destruction of toxic, radioactive,
or other wastes; surplus or banned pesticides
or other chemicals; polluted soils;
and drums containing hazardous materials
from removal actions or accidental releases.
Disposal may be accomplished through
use of approved secure landfills, surface
impoundments, land farming, deep well
injection, ocean dumping, or incineration. |
|
Dissolved
Oxygen (DO) : |
The
oxygen freely available in water. Dissolved
oxygen is vital to fish and other aquatic
life and for the prevention of odors.
Traditionally, the level of dissolved
oxygen has been accepted as the single
most important indicator of a water
body’s ability to support desirable
aquatic life. Secondary and advanced
waste treatment are generally designed
to protect DO in waste-receiving waters. |
|
DISSOLVED
SOLIDS : |
The
weight of matter in true solution in
a stated volume of water; includes both
inorganic and organic matter; usually
determined by weighing the residue after
evaporation of the water at 105 or 180
Degrees Celcius. |
|
DISTILLATION
: |
The
process in which a liquid, such as water,
is converted into its vapor state by
heating, and the vapor cooled and condensed
to the liquid state and collected; used
to remove solids and other impurities
from water, multiple distillations are
required for extreme purity. |
|
|
The
relationship of living things to one
another and their environment, or the
study of such relationships. |
|
Effluent
: |
Wastewater—treated
or untreated—that flows out of
a treatment plant, sewer, or industrial
outfall. Generally refers to wastes
discharged into surface waters. |
|
Electrodialysis
: |
A
process that uses electrical current
applied to permeable membranes to remove
minerals from water. Often used to desalinize
salty or brackish water |
|
Electrostatic
Precipitator (ESP) : |
An
air pollution control device that removes
particles from a gas stream (smoke)
after combustion occurs. The ESP imparts
an electrical charge to the particles,
causing them to adhere to metal plates
inside the precipitator. Rapping on
the plates causes the particles to fall
into a hopper for disposal. |
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EQUIVALENT
PER MILLION : |
A
unit of concentration used in chemical
calculations, calculated by dividing
the concentration in ppm or mg/1 by
the equivalent weight. |
|
Erosion
: |
The
wearing away of land surface by wind
or water. Erosion occurs naturally from
weather or runoff but can be intensified
by land-clearing practices related to
farming, residential or industrial development,
road building, or timber-cutting. |
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Evaporation
Ponds : |
Areas
where sewage sludge is dumped and allowed
to dry out. |
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EXHAUSTION
: |
The
state of an ion exchange material in
which it is no longer capable of effective
function due to the depletion of the
initial supply of exchangeable ions;
the exhaustion point may be defined
in terms of a limiting concentration
of matter in the effluent, or in the
case of demineralization, in terms of
electrical conductivity. |
|
|
Specifically,
a device or system for the removal of
solid particles (suspended solids);
in general, includes mechanical, adsorptive,
oxidizing and neutralizing filters. |
|
Filtration
: |
A
treatment process, under the control
of qualified operators, for removing
solid (particulate) matter from water
by passing the water through porous
media such as sand or a man-made filter.
The process is often used to remove
particles that contain pathogenic organisms. |
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Floc
: |
A
clump of solids formed in sewage by
biological or chemical action. |
|
FLOCCULATION
: |
The
agglomeration of finely divided suspended
solids into larger, usually gelatinous,
particles; the development of a "floc"
after treatment with a coagulant by
gentle stirring or mixing. |
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FLOW
CONTROL : |
A
device designed to limit the flow of
water or regenerant to a predetermined
value over a broad range of inlet water
pressures. |
|
FLOW
RATE : |
The
quantity of water or regenerant which
passes a given point in a specified
unit of time, often expressed in gallons
per minute. |
|
Flowmeter
: |
A
gauge that shows the speed of wastewater
moving through a treatment plant. Also
used to measure the speed of liquids
moving through various industrial processes. |
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FLUORIDATION
: |
The
addition of a fluoride compound to a
water supply to produce the concentration
desired for the reduction in incidence
of dental caries. |
|
Fluorides
: |
Gaseous,
solid, or dissolved compounds containing
fluorine that result from industrial
processes. Excessive amounts in food
can lead to fluor. |
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Fluorocarbon
(FCs) : |
Any
of a number of organic compounds analogous
to hydrocarbons in which one or more
hydrogen atoms are replaced by fluorine.
Once used in the United States as a
propellant in aerosols. they are now
primarily used in coolants and some
industrial processes. FCs containing
chlorine are called chlorofluorocarbons
(CFCs). They are believed to be modifying
the ozone layer in the stratosphere,
thereby allowing more harmful solar
radiation to reach the Earth’s
surface. |
|
Fluorosis
: |
An
abnormal condition caused by excessive
intake of fluorine, characterized chiefly
by mottling of the teeth. |
|
Formaldehyde
: |
A
colorless, pungent, irritating gas,
CH20, used chiefly as a disinfectant
and preservative and in synthesizing
other compounds and resins. |
|
FOULING
: |
The
process in which undesirable foreign
matter accumulates in a bed of filter
media or ion exchanger, clogging pores
and coating surfaces and thus inhibiting
or retarding the proper operation of
the bed. |
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FREEBOARD
: |
The
vertical distance between a bed of filter
media or ion exchange material and the
over flow or collector for backwash
water; the height above the bed of granular
media available for bed expansion during
backwashing; may be expressed either
as a linear distance or a percentage
of bed depth. |
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Fresh
Water : |
Water
that generally contains less than 1,000
milligrams-per-liter of dissolved solids. |
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Fungi
: |
(Singular,
Fungus) Molds, mildews, yeasts, mushrooms,
and puff-balls, a group organisms that
lack chlorophyll (i.e., are not photosynthetic)
and which are usually non-mobile, filamentous,
and multicellular. Some grow in the
ground, others attach themselves to
decaying trees and other plants, getting
their nutrition from decomposing organic
matter. Some cause disease, others stabilize
sewage and break down solid wastes in
composting.Fungicide: Pesticides which
are used to control, prevent, or destroy
fungi. |
|
|
compound
that kills disease-causing microorganisms. |
|
GPG
: |
Abbreviation
for "grain per gallon". |
|
GRAIN
: |
(gr.)
A unit of weight equal to 1/7000th of
a pound, or 0.0648 gram. |
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GRAIN
PER GALLON : |
(gpg)
A common basis for reporting water analyses
in the United States and Canada; one
grain per U.S. gallon equals 17.12 milligrams
per liter (mg/1) or parts per million
(ppm). |
|
GRAM
: |
(g)
The basic unit of weight (mass) of the
metric system, originally intended to
be the weight of 1 cubic centimeter
of water a 4 DegC. |
|
Granular
Activated Carbon Treatment : |
A
filtering system often used in small
water systems and individual homes to
remove organics. GAC can be highly effective
in removing elevated levels of radon
from water. |
|
Gray
Water : |
The
term given to domestic wastewater composed
of washwater from sinks, kitchen sinks,
bathroom sinks and tubs, and laundry
tubs. |
|
Greenhouse
Effect : |
The
warming of the Earth’s atmosphere
caused by a build-up of carbon dioxide
or other trace gases; it is believed
by many scientists that this build-up
allows light from the sun’s rays
to heat the Earth but prevents a counterbalancing
loss of heat. |
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GREENSAND
: |
A
natural mineral, primarily composed
of complex silicates, which possess
ion exchange properties. |
|
|
Water
with a total hardness of one grain per
gallon or more, as calcium carbonate
equivalent. |
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HARDNESS
: |
A
characteristic of natural water due
to the presence of dissolved calcium
and magnesium; water hardness is responsible
for most scale formation in pipes and
water heaters, and forms insoluble "curd"
when it reacts with soaps. Hardness
is usually expressed in grains per gallon,
parts per million, or milligrams per
liter, all as calcium carbonate equivalent. |
|
Heavy
Metals : |
Metallic
elements with high atomic weights, e.g..
mercury, chromium, cadmium, arsenic,
and lead. They can damage living things
at low concentrations and tend to accumulate
in the food chain. |
|
HYDROLOGIC
CYCLE : |
The
water cycle, including precipitation
of water from the atmosphere as rain
or snow, flow of water over or through
the earth, and evaporation or transpiration
to water vapor in the atmosphere. (See
Transpiration) |
|
|
1.
The penetration of water through the
ground surface into sub-surface soil
or the penetration of water from the
soil into sewer or other pipes through
defective joints, connections, or manhole
walls. |
2.
A land application technique where large
volumes of waste water are applied to
land, allowed to penetrate the surface
and percolate through the underlying
soil. (See: percolation) |
|
Inflow
: |
Entry
of extraneous rain water into a sewer
system from sources other than infiltration,
such as basement drains, manholes, storm
drains, and street washing. |
|
Influent
: |
Water,
wastewater, or other liquid flowing
into a reservoir, basin, or treatment
plant. |
|
Insecticide
: |
A
pesticide compound specifically used
to kill or control the growth of insects. |
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ION
EXCHANGE : |
A
reversible process in which ions are
released from an insoluble permanent
material in exchange for other ions
in a surrounding solution; the direction
of the exchange depends upon the affinities
of the ion exchanger for the ions present,
and the concentrations of the ions in
the solution. |
|
Ion
Exchange Treatment : |
A
common water softening method often
found on a large scale at water purification
plants that remove some organics and
radium by adding calcium oxide or calcium
hydroxide to increase the ph to a level
where the metals will precipitate out. |
|
ION
EXCHANGER : |
A
permanent, insoluble material which
contains ions that will exchange reversibly
with other ions in a surrounding solution.
Both Cation and anion exchangers are
used in water conditioning. |
|
Ion
: |
An
electrically charged atom or group of
atoms which can be drawn from waste
water during the electrodialysis process. |
|
IONIZATION
: |
The
process in which atoms gain or lose
electrons and thus become ions with
positive or negative charges; sometimes
used as synonymous with dissociation,
the separation of molecules into charged
ions in solution. |
|
IRON
: |
An
element often found dissolved in ground
water (in the form of ferrous iron)
in concentrations usually ranging from
zero to 10 ppm (mg/1). It is objectionable
in water supplies because of the staining
caused after oxidation and precipitation
(as ferric hydroxide), because of tastes,
and because of unsightly colors produced
when iron reacts with tannins in beverages
such as coffee and tea. |
|
IRON
BACTERIA : |
Organisms
which are capable of utilizing ferrous
iron, either from the water or from
steel pipe, in their metabolism, and
precipitating ferric hydroxide in their
sheaths and gelatinous deposits. These
organisms tend to collect in pipe lines
and tanks during periods of low flow,
and to break loose in slugs of turbid
water to create staining, taste and
odor problems. |
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