Glossary Of Water Treatment Industry Terms . . ."T"
TDS - The abbreviation for
"total dissolved solids".
temporary hardness - Water
hardness due to the presence of calcium and magnesium carbonates and bicarbonates,
which can be precipitated by heating the water. Now largely replaced by
the term "carbonate hardness". (See carbonate hardness, permanent
threshold- A very low
concentration of a substance in water. The term is sometimes used to indicate
the concentration which can just be detected.
throughput volume - The
amount of solution passed through an ion exchange bed before the ion exchanger
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). (See acidity.)
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. (see alkalinity.)
total cations - This is
the sum of Ca + Mg _ Na + K all reported in gpg as CaCO3. These
are "positive" ions and are generally metals. Total cations
should always equal total anions.
total chlorine - The total
concentration of chlorine in a water, including combined and free chlorine.
(See combined available chlorine, free available chlorine.)
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 hardness - The sum
of all hardness constituents in a water, expressed as their 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. (See hardness.)
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 105oC in a pre-weighted dish.
toxic - Having an adverse
physiological effect on humans or other desirable organisms.
trace - A very small concentration
of a material, high enough to be detected but too low to be measured by
standard analytical methods.
transpiration - The process
in which living plants release water vapor into the atmosphere, a significant
part of the hydrologic cycle.
tuberculation - The process
in which blister-like growths of metal oxides develop in pipes as a result
of the corrosion of the pipe metal. Iron oxide tubercles often develop
over pits in iron or steel pipe, and can seriously restrict the flow of
turbidity - A measure of
the cloudiness in water, the result of finely divided particulate matter
suspended in water; usually reported in arbitrary units determined by
measurements of light scattering. (See Nephelometric Turbidity Unit.)
turbulent flow - A type of flow characterized by cross currents and eddies, as opposed to laminar or streamlined flow. Turbulence may be caused by surface roughness or protrusions in pipes, bends and fittings, changes in channel size, or excessive flow rates; turbulence significantly increases pressure drops.