Environmental Engineering Reference
In-Depth Information
Biomass:
The amount of living matter, in the form of organisms, present in a
particular habitat, usually expressed as weight per unit area.
Biota:
All living organisms of an area.
Bog:
A nutrient-poor, acidic wetland dominated by a waterlogged, spongy
mat of sphagnum moss that ultimately forms a thick layer of acidic
peat; it generally has no inflow or outflow and is fed primarily by
rain water.
Brackish water:
Water with a salinity intermediate between seawater and
freshwater (containing from 1000 to 10,000 mg/L of dissolved solids).
Breakdown product:
A compound derived by chemical, biological, or physi-
cal action upon a pesticide. The breakdown is a natural process that
may result in a more toxic or a less toxic compound and a more per-
sistent or less persistent compound.
Breakpoint chlorination:
The addition of chlorine to water until the chlo-
rine demand has been satisfied and free chlorine residual is avail-
able for disinfection.
C
Calcareous:
Refers to substance formed of calcium carbonate or magnesium
carbonate by biological deposition or inorganic precipitation, or con-
taining those minerals in sufficient quantities to effervesce when
treated with cold hydrochloric acid.
Capillary fringe:
The zone above the water table in which water is held by
surface tension. Water in the capillary fringe is under a pressure less
than atmospheric.
Carbonate rocks:
Rocks (such as limestone or dolostone) that are composed
primarily of minerals (such as calcite and dolomite) containing a car-
bonate ion.
Center pivot irrigation:
An automated sprinkler system with a rotating pipe
or boom that supplies water to a circular area of an agricultural field
through sprinkler heads or nozzles.
Channel scour:
Erosion by flowing water and sediment on a stream channel;
results in removal of mud, silt, and sand on the outside curve of a
stream bend and the bed material of a stream channel.
Channelization:
The straightening and deepening of a stream channel to
permit the water to move faster or to drain a wet area for farming.
Chemical treatment:
A process that results in the formation of a new substance
or substances. The most common chemical water treatment processes
include coagulation, disinfection, water softening, and filtration.
Chlordane:
Octachlor-4,7-methanotetrahydroindane; an organochlorine
insecticide no longer registered for use in the United States. Technical
chlordane is a mixture in which the primary components are
cis
-
and
trans
-chlordane,
cis
- and
trans
-nonachlor, and heptachlor.
