Water
Terms Glossary
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.
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."
ABSORBENT
A substance which has the capacity to adsorb.
ADSORPTION
The process in which matter adheres to the surface of an adsorbent.
ALKALINITY
The quantitative capacity of 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. A moderate amount of Alkalinity
in your water is desirable because it reduces the effect of
corrosion. The EPA has not set a level for Alkalinity, but
a level greater than 100 ppm is recommended
ALUMINUM
Aluminum can be found as a natural forming mineral or as a
by product of water that is corrosive or aggressive. Aluminum
in the water may cause a discoloration or cloudy appearance.
The EPA maximum contaminant level for aluminum in water is
0.2 ppm.
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 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.
AQUIFER
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 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.
BACKWASH
The process in which beds of filter or ion exchange media
are subjected to flow opposite to the service direction to
loosen the bed and to flush suspended matter (collected during
the service run) to waste.
BACTERIA
Unicellular micro-organisms which typically reproduce by cell
division. Although usually classified as plants, bacteria
contain no chlorophyll.
BASE
A substance which releases hydroxyl ions which when dissolved
in water. Bases react with acids to form a neutral salt and
water.
BED
The ion exchange or filter media in a column or other tank
or operational vessel.
BED DEPTH
The height of the ion exchange or filter media in the vessel
after preparation for service.
BICARBONATE ALKALINITY
The alkalinity of a water due to the presence of bicarbonate
ions (HCO3 -).
BIOCHEMICAL OXYGEN DEMAND
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.
BRINE
A strong solution of salts(s), such as the sodium chloride
brine used in the regeneration of ion exchange water softeners;
also applied to the mixed sodium, calcium, and magnesium chloride
waste solution from regeneration.
CALCIUM
One of the principal elements making up the earth's crust;
its compounds, when dissolved, make the water hard. The presence
of calcium in water is a factor contributing to the formation
of scale and insoluble soap curds which are a means of clearly
identifying hard water.
CALCIUM MAGNESIUM
Two of the principal elements making up the earth's crust;
its compounds, when dissolved, make the water hard. The presence
of calcium and magnesium in water is a factor contributing
to the formation of scale and insoluble soap curds 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 servicing of
the media (i.e., 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 regeneration's 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.
CARBONATE
The CO3- ion.
CARBONATE ALKALINITY
Alkalinity due to the presence of the carbonate ion.
CARBONATE HARDNESS
Hardness due to the presence of calcium and magnesium bicarbonates
and carbonates in water; the smaller of the total hardness
and the total alkalinity.
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.
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 from an ion exchanger.
CAUSTIC
Any substance capable of burning or destroying animal flesh
or tissue. The term is usually applied to strong bases.
CAUSTIC SODA
The common name for sodium hydroxide.
CHELATE
To form a complex chemical compound in which an ion, usually
metallic, is bound into a stable ring structure.
CHELATING AGENT
A chemical compound sometimes fed to water to tie up undesirable
metal ions, keep them in solution, and eliminate or reduce
the normal effects of the ion.
CHEMICAL OXYGEN DEMAND
The amount of matter, both organic and inorganic, in a water
or waste water which can be oxidized by boiling with a strong
oxidizing acid under standard test conditions and expressed
as the equivalent amount of oxygen; often used as a measure
of the strength of sewage and waste water; includes materials
not oxidized in the BOD test, and thus does not correlate
with BOD.
CHLORIDE
Chloride is a natural forming mineral found in water. High
levels of chloride can impact taste and also be associated
with corrosion or high Sodium content. Water with excessive
amounts of chloride can be very toxic to most plants. The
EPA maximum contaminant level for chloride is 250 ppm.
CHLORINE
A gas, C12, widely used in the disinfection of water and an
oxidizing agent for organic matter, iron, etc.
CHLORINE CONTENT
Chlorine is added to water as a disinfectant to kill harmful
organisms or bacteria. Even though Chlorine is used in providing
safe drinking water, when it is in excess, it is the most
common cause of taste and odor problems. Also when Chlorine
is combined with ammonia as a disinfectant called chloramines,
a byproduct as Trihalomethanes are formed, which cause cancer.
The EPA does not have a level for Chlorine but a concentration
of 0.1 to 0.2 ppm is recommended and a level of 1.0 or greater
is considered very high.
CHLORINE DEMAND
A measure of the amount of chlorine which will be consumed
by organic matter and other oxidizable substances in a water
before a chlorine residual will be found; the difference between
the total chlorine fed and the chlorine residual.
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.
COAGULANT AID
A material which is not a coagulant, but which improves the
effectiveness of a coagulant, often by forming larger or heavier
particles, speeding the reactions, or permitting reduced coagulant
dosage.
COAGULATION
The process in which very small, finely divided solid particles,
often colloidal in nature, are agglomerated into larger particles.
COLLOID
Very finely divided solid particles which will not settle
out of a solution; intermediate between a true dissolved particle
and a suspended solid which will settle out of solution. The
removal of colloidal particles usually requires coagulation
to form larger particles which may be removed by sedimentation
and/or filtration.
COMPENSATED HARDNESS
A calculated value based on the total hardness, the magnesium
to calcium ratio, and the sodium concentration of a water.
It is used to correct for the reductions in hardness removal
capacity caused by these factors in cation exchange water
CONDUCTANCE
A measure of the ability of a solution to carry electricity;
the reciprocal of the electrical resistance. The unit of conductance
is the mho (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.
COPPER
Copper in water is a common problem in many households. Copper
is present due to the corrosion of plumbing materials from
Acidic (low pH) or Aggressive water (low TDS). Common problems
associated with copper due corrosion are leaks in the plumbing
system or blue-green staining. High copper content can also
cause some health concerns by effecting the stomach and intestines.
The EPA has set a maximum contaminant level of 1.3 ppm.
CORROSION
The destructive disintegration of a metal by electrochemical
means.
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.
DEIONIZATION
The removal of all ionized minerals and salts (both organic
and inorganic) from a solution by a two-phase ion exchange
procedure. First, positively charged ions are exchanged 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.
D.I. OR DI
Abbreviation for deionization.
DIALYSIS
The separation of components of a solution by diffusion through
a semi-permeable membrane which is capable of passing certain
ions or molecules while rejecting others.
DIFFERENTIAL PRESSURE
The difference in pressures at two points in a water system;
may be due to differences in elevation, or to friction losses
or pressure drops due to resistance to flow in pipes, softeners,
filters or other devices.
DISINFECTION
A process in which pathogenic (disease-producing) bacteria
are killed; may involve disinfecting agents such as chlorine,
or physical processes such as heating.
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 1800C.
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.
EFFICIENCY
The ratio of output per unit input; the effectiveness of performance
of a system; in an ion exchange system, often expressed as
the amount of regenerant required to produce a unit of capacity,
such as the pounds of salt per kilograin of hardness removal.
ELECTRODIAYSIS
A process in which a direct current is applied to a cell to
draw charged ions through ion-selective semi-permeable membranes,
thus removing the ions from the solution.
ENDPOINT
The point at which a process is stopped because a predetermined
value of a measurable variable is reached; the endpoint of
an ion exchange water softener service run is the point at
which the hardness of the softener effluent increases to a
predefined concentration, often 1.0 grain per gallon; the
endpoint of a filter service run may be the point at which
the pressure drop across the filter reaches a predetermined
value; the endpoint of a titration is the point at which the
titrant produces predetermined color change, pH value, or
other measurable characteristic.
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.
EXHAUSTION
The state of an ion exchange material in which it is no longer
capable of effective functioning 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.
FILTER
Specifically, a device or system for the removal of solid
particles (suspended solids); in general, includes mechanical,
adsorptive, oxidizing and neutralizing filters.
FIXTURE UNIT
An arbitrary unit assigned to different types of plumbing
fixtures, and used to estimate flow rate requirements and
drain capacity requirements.
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.
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.
FLUORIDATION
The quantity of water or regenerant which passes a given point
in a specified unit of time, often expressed in gallons per
minute.
FLUORIDE
Fluoride can be found in water as natural mineral or as an
additive to public or municipal supplies. Fluoride can cause
a discoloration or teeth known as Fluorosis when in excessive
levels in water. The EPA maximum contaminant level for Fluoride
in water is 2.0 ppm.
FLUSH TANK
A tank or chamber in which water is stored for rapid release
to flush a toilet or water closet.
FLUSH VALVE
A self-closing valve designed to release a large volume of
water when tripped, to flush a toilet or water closet.
FOULING
The process in which undesirable foreign matter accumulates
in a bed of filter media or ion exchanger, clogging pores
and coating surfaces, thus inhibiting or retarding the proper
operation of the bed.
FREE AVAILABLE CHLORINE
The concentration of residual chlorine present as dissolved
gas, hypochlorous avid or hypochlorite, not combined with
ammonia or in other less readily available forms.
FREEBOARD
The vertical distance between a bed of filter media or ion
exchange material and the overflow 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.
GPG
Abbreviation for grains per gallon.
GRAIN
(gr.) A unit of weight equal to 1/7000th of a pound, or 0.0648
gram.
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). One
grain per British (Imperial) gallon equals 14.3 milligrams
per liter or parts per million.
GRAM
(g) The basic unit of weight (mass) of the metric system,
originally intended to be the weight of one cubic centimeter
of water at 4oC.
GREENSAND
A natural mineral, primarily composed of complex silicates,
which possesses ion exchange properties.
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.
HARDNESS CONTENT
Hardness is a measurement of naturally occurring dissolved
minerals Calcium and Magnesium, hard water can inhibit the
sudsing of detergents and soaps. Hard water can scale pipes
and decrease the life of appliances such as washing machines,
dishwashers, coffee makers. Hardness can also cause spotting
of fixtures, tiles, dishes, or glassware. The EPA has not
set a limit for hardness, but if your hardness is greater
than 7 grains per gallon (gpg) then you should consider installing
a water softener.
HARDNESS LEAKAGE
The presence of a consistent concentration of hardness in
the effluent from an ion exchange water softener, often due
to high concentrations of hardness or sodium in the water
being treated (see Leakage).
HARD WATER
Water with a total hardness of one grain per gallon or more,
as calcium carbonate equivalent.
HEAD
A measure of the pressure at a point tin a water system: expressed
in pounds per square or in the height of a column of water
which would produce the pressure.
HEAD LOSS
See Pressure Drop.
HYDRAULIC
Referring to water or other fluids in motion.
HYDRAULIC CLASSIFICATION
A process in which particles of the same specific gravity
may be graded according to size by backwashing or other relative
upward flow of water; the smallest particles tending to rise
to the top of the bed, and the largest particles tending to
sink to the bottom, due to variations in weight to surface
area ratios.
HYDROGEN CYCLE
The cation exchange cycle in which the cation exchanger is
regenerated with acid, and cations are removed from the solution
treated in exchanged for hydrogen ions.
HYDROGEN ION CONCENTRATION
The concentrations of hydrogen ions in moles per liter of
solution; often expressed as pH (see pH).
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).
HYDROLYSIS
The reaction of a salt with water to form an acid and a base.
HYDROXIDE
A chemical compound of an element or elements with the hydroxyl
(OH) anion. (see Hydroxyl).
HYDROXYL
The chemical group or ion (OH) which is neutral or positively
charged.
HYPOCHLORITE
The "OC1" anion; calcium and sodium hypochlorites
are commonly used as bleaches and disinfecting agents.
ION
An atom or group of atoms which functions as a unit, and has
a positive or negative electrical charge, due to the gain
or loss of one or more electrons. (see Ionization).
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 ion present, and the concentrations
of the ions in the solution. (see Base Exchange).
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.
IONIZATION
The process in which atoms gain or lose electrons and thus
become ions with positive or negative charges; sometimes used
as a synonym for dissociation, the separation of molecules
into charged ion in solution.
IONIZATION CONSTANT
A constant, specific for each partially ionizable chemical
compound to express the ratio of the concentration of ions
from the compound to the concentrate of un-ionized compound.
IRON
An element often found discolored 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 it can effect water taste and cause unsightly colors
produced when iron reacts with tannins in beverages such as
coffee and tea. Iron causes staining after oxidation and precipitation,
as ferric hydroxide (yellow, brown, and red on clothing, dishes,
fixtures, and bathroom tile). Iron can also be found in a
bacterial form which will appear as black or brown slime and
can effect the odor of your water. Iron is a common water
problem throughout the United States, it can be found in well
water and municipal water. The EPA has set a maximum level
for Iron of 0.3 ppm in water, iron concentrations at this
level or higher can cause staining.
IRON BACTERIA
Organisms which are capable of utilizing ferrous iron (either
from the water or from steel pipe) in their metabolism and
precipitating both 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.
JACKSON TURBIDITY UNIT (JTU)
A quantitative unit of turbidity originally based on the comparison
of a liquid (such as water) with a suspension of a specify
type of silica, using the turbidity measure in a Jackson Candle
Turbidimeter.
KILO: A prefix used to
indicate 1000 of the succeeding unit. (Kilo is also sometimes
used as an abbreviation for kilogram.)
KILOGRAIN (Kgr)
One thousand grains.
KILOGRAM (Kg)
One thousand grams.
LANGELIER'S INDEX
A calculated number used to predict whether or not a water
will precipitate, be in equilibrium with, or dissolve calcium
carbonate. It is sometimes erroneously assumed that any water
which tends to dissolve calcium carbonate is automatically
corrosive.
LEAD
Lead in drinking water is a common problem, it comes from
lead pipes, solder, and brass fittings. Water that has a low
pH or Total Dissolved Solids will provide corrosive properties
that can leach from your plumbing system. Lead can cause learning
and physical disabilities in children and also Hypertension
in adults. The EPA action level for Lead is 0.015 ppm.
LEAKAGE
The amount of contaminant or hardness remaining in water after
filtering or other treatment.
LIME
The common name for calcium oxide (Ca); hydrated lime is calcium
hydroxide [Ca(OH)2].
LIME SCALE
Hard water scale containing a high percentage of calcium carbonate.
LIMESTONE
A sedimentary rock, largely calcium carbonate, usually also
containing significant amounts of magnesium carbonate.
LITER
The basic metric unit of volume; 3.785 liters equals one U.S.
gallon. One liter of water weighs 1000 grams.
MAGNESIUM
One of the elements making up the earth's crust. Magnesium
compounds, when dissolved in water, make the water hard. The
presence of magnesium in water is a factor contributing to
the formation of scale and insoluble soap curds.
MANGANESE
An element sometimes found in ground water, usually with dissolved
iron but in lower concentrations. Manganese is a typical natural
occurring mineral found in municipal and well water. Manganese
effects the taste and the color or water. Manganese can also
cause staining of clothes and dishware and black stains and
other problems similar to iron. The EPA has determined that
concentrations greater than 0.05 ppm can cause these asethic
problems.
MANGANESE GREENSAND
Greensand which has been processed to incorporate in its pores
and on its surface the higher oxides of manganese. The product
has a mild oxidizing power, and is often used in the oxidation
and precipitation of iron, manganese and/or hydrogen sulfide,
and in their removal from water.
MEDIA
The selected materials in a filter that form the barrier to
the passage of certain suspended solids or dissolved molecules.
MEDIUM
Singular form of media.
MG/L
The abbreviation for milligrams per liter.
MICRON
A linear measure equal to one millionth of a meter.
MICRON RATING
The term applied to a filter to indicate the particle size
of suspended solids that will be removed. As used in industry
standards, this is an "absolute" not nominal rating.
MILLIGRAM PER LITER (mg/l)
A unit concentration of matter used in reporting the results
of water and waste water analyses. In diluted water solutions
it is practically equal to the part per million, but varies
from he ppm in concentrated solution such as brine. As most
analyses are performed on measured volumes of water the mg/l
is a more accurate expression of the concentration, and is
the preferred unit of measure.
MILLIMICRON
A unit of length equal to one thousandth of a micron, often
used to express the wavelengths of colors of visible light
in colorimetric analytical procedures. The symbol for the
millimicron is "mu".
MINERAL
A term applied to inorganic substances (such as rocks and
similar matter) found in the earth strata, as opposed to organic
substances such as plant and animal matter. Minerals normally
have definite chemical composition and crystal structure.
The term is also applied to matter derived from minerals,
such as the inorganic ions found in water. The term has been
incorrectly applied to ion exchangers, even though most of
the modern materials are organic ion exchange resins.
MOLE
The molecular weight of a chemical compound expressed in grams.
MOLECULE
The simplest combination of atoms that will form a specific
chemical compound; the smallest particle of a substance which
will still retain the essential composition and properties
of that substance, and which can be broken down only into
atoms and simpler substances.
MOST PROBABLE NUMBER (MPN)
The term used to indicate the number of organisms which, according
to statistical theory, would be most likely to produce the
results observed in certain bacteriological tests; usually
expressed as a number in 100 ml of water.
NEGATIVE CHARGE
The electrical charge on an electrode or ion in solution due
to the presence of an excess of electrons.
NEUTRAL
In electrical systems, the term used to indicate neither an
excess nor a lack of electrons; a condition of balance between
positive and negative charges. In chemistry, the term used
to indicate a balance between acids and bases; the neutral
point on the pH scale is 7.0, indicating the presence of equal
numbers of free hydrogen (acidic) and hydroxide (basic) ions.
NEUTRALIZATION
In general, the addition of either and acid or a base to a
solution as required to produce a neutral solution. The use
of alkaline or basic materials to neutralize the acidity of
some waters is a common proactive in water conditioning.
NITRATE NITROGEN
Nitrates are commonly found in well water from agricultural
areas. It comes from fertilizers, industrial wastes, septic
systems, and animal wastes. High amounts of nitrate effect
the bloods ability to carry oxygen. Most susceptible are infants
where nitrate poisoning can cause death by a health diagnosis
known as "The Blue Baby Syndrome." The EPA has a
set maximum contaminant level of 10 ppm for Nitrate Nitrogen.
NONCARBONATE HARDNESS
Water hardness due to the presence of compounds such as calcium
and magnesium chlorides, sulfates or nitrates; the excess
of total hardness over total alkalinity.
OPERATING PRESSURE
The range of pressure, usually expressed in pounds per square
inch, over which a water conditioning device or water system
is designed to function.
OSMOSIS
A process of diffusion of a solvent (such as water ) through
a semi-permeable membrane which will transmit the solvent
but impede most dissolved substances. The normal flow of solvent
is from the dilute solution to the concentrated solution.
OXIDATION
A chemical process in which electrons are removed from an
atom, ion or compound. The addition of oxygen is a specific
form of oxidation. Combustion is an extremely rapid form of
oxidation, while the rusting of iron is a slow form.
PARTICLE SIZE
As used in industry standards, the size of a particle suspended
in water as determined by its smallest dimension, usually
expressed in microns.
PARTS PER MILLION (ppm)
A common basis for reporting the results of water and waste
water analyses, indicating the number of parts by weight of
a dissolved or suspended constituent, per million parts by
weight or water or other solvent. In dilute water solutions,
one part per million is practically equal to one milligram
per liter, which is the preferred unit.
PATHOGEN
An organism which may cause disease.
PERMANENT HARDNESS
Water hardness due to the presence of the chlorides and sulfates
of calcium and magnesium, which will not be precipitated by
boiling. This term is largely replaced by "noncarbonate
hardness."
pH
The reciprocal of the logarithm of the hydrogen ion concentration.
The pH scale is from zero to 14, and 7.0 is the neutral point,
indicating the presence of equal concentrations of free hydrogen
and hydroxide ions. pH values below 7.0 indicate increasing
acidity, and pH values above 7.0 indicate increasing base
concentrations.
PORTABLE EXCHANGE
A term applied to water softeners and filters which are designed
for connection to a water system with special fittings, and
disconnection and transport to a central station or plant
for regeneration or servicing.
POSITIVE CHARGE
The electrical charge on an electrode or ion in solution due
to the removal of electrons.
PPM
The abbreviation for part per million.
PRECIPITATE
To cause a dissolved substance to form a solid particle which
can be removed by settling or filtering, such as in the removal
of dissolved iron by oxidation, precipitation, and filtration.
The term is also used to refer to the solid formed, and to
the condensation of water in the atmosphere to form rain or
snow.
PRESSURE DIFFERENTIAL
The difference in pressure between two points in a system
due to differences in elevation and/or pressure drop due to
flow.
PRESSURE DROP
A decrease in water pressure during flow due to internal friction
between molecules of water, and external friction due to irregularities
or roughness in surfaces past which the water flows.
RATED CAPACITY
The basis for calculating the number of gallons delivered
by a water softener between regeneration's, or amount of time
between servicing of a filter, as determined under specific
test conditions.
RATED PRESSURE DROP
The pressure drop of a freshly regenerated and/or backwashed
water softener or filter at the rated service flow, with clean
water at a temperature of 60 F, as determined under standard
test conditions.
RATED SERVICE FLOW
The manufacturer's specified maximum flow rate at which a
water softener will deliver soft water, or a filter will deliver
quality water (as specified for its type) as determined under
standard test conditions. A manufacturer may also specify
a minimum flow rate or a range of service flows.
RATED SOFTENER CAPACITY
A water softener capacity rating based on grains of hardness
removed while producing soft water between successive regeneration's,
and related to the pounds of salt required for each regeneration
as determined under standard test conditions.
RAW WATER
Untreated water, or any water before it reaches a specific
water treatment device or process.
REDUCTION
A chemical process in which electrons are added to an atom,
ion or compound.
RED WATER
Water which has a reddish or brownish appearance due to the
presence of precipitated iron and/or iron bacteria.
REGENERANT
A solution of chemical compound used to restore the capacity
of an ion exchange system. Sodium chloride brine is used as
a regenerate for ion exchange water softeners; acids and bases
are used as regenerants for the cation and anion resins used
in demineralization.
REGENERATION
In general, includes the backwash, brine, and fresh water
rinse steps necessary to prepare a water softener exchange
bed for service after exhaustion. Specifically, the term may
be applied to the "brine" step in which the sodium
chloride solution is passed through the exchanger bed. The
term may also be used for similar operations relating to demineralizers
and certain filters.
REGENERATION LEVEL
The quantity of regenerant used in regeneration of an ion
exchange unit or system, usually expressed in pounds per regeneration
and/or pounds per regeneration per cubic foot of ion exchange.
RESIDUAL
The amount of a specific material remaining in the water following
a water treatment process. May refer to material remaining
as a result of incomplete removal (see Leakage) or to material
meant to remain in the treated water (see Residual Chlorine).
RESIDUAL CHLORINE
The amount of chlorine found in the water after treatment.
RESIN
Synthetic organic ion exchange material, such as the high
capacity cation exchange resin widely used in water softeners.
REVERSE DEIONIZATION
The use of the anion exchange resin ahead of the cation exchange
resin (the reverse of the usual order ) in a deionization
system.
REVERSE OSMOSIS
A process for the removal of dissolved ions from water, in
which pressure is used to force the water through a semi-permeable
membrane, which will transmit the water by reject most other
dissolved materials.
SALINE WATER
Water containing an excessive amount of dissolved salts, usually
over 10,000 mg/1.
SALT
The common name for the specific chemical compound sodium
chloride, used in the regeneration of ion exchange water softeners.
In chemistry, the term is applied to a class of chemical compounds
which can be formed by the neutralization of an acid with
a base.
SEQUESTER
A chemical reaction in which certain ions are bound into a
stable, water soluble compound, thus preventing undesirable
action by the ions.
SEQUESTERING AGENT
A chemical compound sometimes fed into water to tie up undesirable
ions, keep them in solution, and eliminate or reduce the normal
effects of the ions. For example, polyphosphates can sequester
hardness and prevent reactions with soap.
SILICA
Silica can be found in water as a natural forming mineral
or an additive to public water supplies. Silica is not regulated
by the EPA and does not cause any health concerns. However,
silica can cause spotting of glassware, fixtures, and automobiles
during the cleaning process.
SOAP
One of a class of chemical compounds which possesses cleaning
properties, formed by the reaction of a fatty acid with a
base or alkali. Sodium and potassium soaps are soluble and
useful, but can be converted to insoluble calcium and magnesium
soaps (curd) by the presence of these hardness ions in water.
SODA ASH
The common name for sodium carbonate, a chemical compound
used as an alkaline builder in come soap and detergent formulations;
to neutralize acid water,; and in the lime-soda ash water
treatment process.
SODIUM
An ion found in natural water supplies, and introduced to
water in the ion exchange water softening process. Sodium
compounds are highly soluble, and do not react with soaps
or detergents. The effects of Sodium are not clearly understood.
A high sodium intake can effect your blood pressure and cause
stress. The EPA has set a maximum contaminant level of 20
ppm for people who have a sodium restricted diet.
SODIUM CHLORIDE
The chemical name for common salt, widely used in the regeneration
of ion exchange water softeners.
SOFT WATER
Any water which contains less than 1.0 fpf (17/1 mg/1) of
hardness minerals, expressed as calcium carbonate.
SOFTENED WATER
Any water that is treated to reduce hardness minerals to 1.0
gpg (17/1 mg/1) or less, expressed as calcium carbonate.
SOLUTE
The substance which is dissolved in a solvent. Dissolved solids,
such as the minerals found in water, are solutes.
SOLVENT
The liquid, such as water, in which other materials (solutes
) are dissolved.
SPECIFIC GRAVITY
The ratio of the weight of a specific volume of a substance
to the weight of the same volume of pure water at 4 C.
SULFATE
Sulfate is a natural forming mineral found in water. Sulfate
effects the taste of water, and when combined with bacteria
or heated (water heater) may effect the odor. High levels
of Sulfate may impact the digestion system causing a laxative
effect. The EPA maximum contaminant level for sulfate in water
is 250 ppm.
SULFATE-REDUCING BACTERIA
A group of bacteria which are capable of reducing sulfates
in water to hydrogen sulfide gas, thus producing obnoxious
tastes and odors. These bacteria have no sanitary significance,
and are classed as nuisance organisms.
SULFUR
A yellowish solid element. The term is also used as a slang
expression to refer to water containing hydrogen sulfide gas.
TANNIN
Tannin is a common natural occurrence in well water. Tannin
is produced by decaying vegetation in the well system. It
causes the water to have a yellow of light brown color and
can provide a bitter taste. There is currently no EPA regulatory
level for tannin in water.
TDS
The abbreviation for total dissolved solids.
THRESHOLD
A very low concentration of a substance in water. The term
is sometimes used to indicate the concentration which can
just be detected.
TITRATION
An analytical process in which a standard solution in a calibrated
vessel is added to a measured volume of sample until an endpoint,
such as a color change, is reached. From the volume of the
sample and the volume of standard solution used, the concentration
of a specific material may be calculated.
TOTAL ACIDITY
The total of all forms of acidity, including mineral acidity,
carbon dioxide, and acid salts. Total acidity is usually determined
by titration with a standard base solution to the phenolphthalein
endpoint (pH 8.3).
TOTAL ALKALINITY
The alkalinity of a water as determined by titration with
standard acid solution to the methyl orange endpoint (pH approximately
4.5); sometimes abbreviated as "M alkalinity." Total
alkalinity includes many alkalinity components, such as hydroxides,
carbonates, and bicarbonates.
TOTAL DISSOLVED SOLIDS (TDS)
The weight of solids per unit volume of water which are in
true solution; usually determined by the evaporation of a
measured volume of filtered water and determination of the
residue weight. Total Dissolved Solids is a measurement of
any minerals or salts in the water. Bicarbonate, Chloride,
Sulfate, Calcium, Magnesium, Sodium are the major components
of dissolved solids in water. High amounts of these salts
provide the major cause of water taste problems. High TDS
can cause the water to appear inappropriate to drink, and
spotting of glassware, fixtures, or painted surfaces such
as automobiles. Also high dissolved solids can diminish the
life of home appliances. The EPA has set a maximum contaminant
level of 500 ppm.
TOTAL HARDNESS
The sum of all hardness constituents in a water, expressed
as the equivalent concentration of calcium carbonate. Primarily
due to calcium and magnesium in solution, but may include
small amounts of metals such as iron which can act like calcium
and magnesium in certain reactions.
TOTAL SOLIDS
The weight of all solids ( dissolved and suspended, organic
and inorganic) per unit volume of water; usually determined
by the evaporation of a measured volume of water at 105 C
in a pre-weighed dish.
TURBIDITY
A measure of the amount of finely divided suspended matter
in water, which causes the scattering and adsorption of light
rays.
ZINC
Zinc is a product of a corrosive or aggressive water that
is in contact with a galvanized plumbing system. Zinc can
effect the taste and color of the water. The EPA maximum contaminant
level for zinc is 5.0 ppm. |
