Glossary Of Water Treatment
Industry Terms . . . "M"
M alkalinity - Methyl
orange alkalinity. (See total alkalinity.)
macroreticular - A term
applied to ion exchange resins that have a rigid polymer porous network
in which there exists a true pore structure even after drying. The pores
are larger than atomic distances and are not a part of the gel structure.
magnesium - One of the
elements in the earth's crust, the compounds of which 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 dissolved in ground water, usually with dissolved iron
but in lower concentration; causes black stains and other problems similar
to iron. It can be removed by a water softener or it can be precipitated
by chlorine at a pH of 9.5 or above.
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 their removal from water (see greensand,
manganese zeolite - Synthetic
gel zeolite which has been processed in the same manner as manganese greensand,
and used for similar purposes.
MBAS - Abbreviation for "Methylene
Blue active Substance".
MCL- Abbreviation for "Maximum
Contaminant Level"; the maximum allowable concentration of a contaminant
in water as established in the U.S. EPA Drinking Water Regulations.
mechanical filter- A filter
primarily designed for the removal of suspended solid particles, as opposed
to filters with additional capabilities.
media- The plural form of
medium- A material used in
a filter bed to form a barrier to the passage of certain suspended solids
or dissolved molecules.
Methylene Blue Active Substances
- Chemical compounds which react with methylene blue to form a blue
compound which can be used to estimate the concentration by measurement
of the depth of color. Substances measured include ABS and LAS types of
detergents, thus the term is commonly used as an expression of detergent
concentration. (See detergent.)
mg/L - The abbreviation for
milligrams per liter.
micrometer - Formally
known as micron. A linear measure equal to one millionth of a meter or
.00003937 inch. The symbol for the micrometer is "um".
micron- See micrometer.
micron rating - The term
applied to a filter medium to indicate the particle size above which all
suspended solids will be removed throughout the rated capacity. As used
in industry standards, this is an "absolute" not "nominal"
mil- One thousandth of an inch.
milli- The prefix used with
units of measure to indicate one thousandth of the unit. Example: a milliliter
is one thousandth of a liter.
milligram per liter (mg/L)
- A unit concentration of matter used in reporting the results of
water and waste water analyses. In dilute water solutions, it is practically
equal to the part per million, but varies from the ppm in concentrated
solutions 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 - (archaic)
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 applied to ion
exchangers, stemming from the early use of natural zeolite. The term is
inappropriate to the modern organic ion exchange resins.
mineral acidity- Acidity
due to the presence of inorganic acids such hydrochloric, sulfuric and
nitric acids, as opposed to acidity due to carbonic acid or organic acids.
mole - 6.02 x 1023
atoms of an element or 6.02 x 1023 molecules of a chemical
compound. The weight of one mole of an element is equal to its atomic
weight in grams; the weight of one mole of a compound is equal to its
molecular weight 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 microorganisms which, according to
statistical theory, would be most likely to produce the results observed
in certain bacteriological tests; usually expressed as a number per 100
ml of water.
MPN - The abbreviation for "most probable number".