Environmental Engineering Reference
In-Depth Information
Methane:
A colorless, flammable, odorless hydrocarbon gas (CH
4
) that is the major
component of natural gas. It is also an important source of hydrogen in vari-
ous industrial processes. Methane is a greenhouse gas.
Methanogens:
Bacteria that synthesize methane, requiring completely anaerobic
conditions for growth.
Methanol:
Also known as methyl alcohol or wood alcohol and having the chemical
formula CH
3
OH. Methanol is usually produced by chemical conversion at
high temperature and pressure. Although usually produced from natural
gas, methanol can be produced from gasified biomass.
Microseismicity:
Small movements of the Earth causing fracturing and movement
of rocks. Such seismic activity does not release sufficient energy for the
events to be recognized except with sensitive instrumentation.
Migratory nongame birds of management concern:
Species of nongame birds
that (1) are believed to have undergone significant population declines, (2)
have small or restricted populations, or (3) are dependent upon restricted or
vulnerable habitats.
Mineral:
Any of the various naturally occurring inorganic substances, such as met-
als, salt, sand, stone sulfur, and water, usually obtained from the Earth.
Note:
For reporting on the Financial Reporting System the term also
includes organic nonrenewable substances that are extracted from the Earth
such as coal, crude oil, and natural gas.
Mineral rights:
Ownership of the minerals beneath the Earth's surface with the
right to remove them. Mineral rights may be conveyed separately from sur-
face rights.
Mini-frac:
A small fracturing treatment performed before the main hydraulic fractur-
ing treatment to acquire stress data and to test prestimulation permeability.
Minimum streamflow:
The lowest rate of flow of water past a given point during a
specified period.
Mitigation:
Actions to compensate for the negative effects of a particular project.
Moisture content:
The water content of a substance (a solid fuel) as measured under
specified conditions: (1) “dry basis,” which equals the weight of the wet
sample minus the weight of a (bone) dry sample divided by the weight of
the dry sample times 100 (to get percent); or (2) “wet basis,” which is equal
to the weight of the wet sample minus the weight of the dry sample divided
by the weight of the wet sample times 100.
Mole:
The quantity of a compound or element that has a weight in grams numeri-
cally equal to its molecular weight. Also referred to as
gram molecule
or
gram molecular weight
.
MSW (municipal solid waste):
Residential solid waste and some nonhazardous
commercial, institutional, and industrial wastes.
MTBE (methyl tertiary-butyl ether):
A fuel oxygenate produced by reacting meth-
anol with isobutylene.
Multiplier effect:
Sometimes called the
ripple effect
, term refers to a single expen-
diture in an economy can have repercussions throughout the entire econ-
omy. The multiplier is a measure of how much additional economic activity
is generated from an initial expenditure.
