A
Abiotic
factors: |
Non living;
moisture, soil, nutrients, fire, wind, temperature,
climate |
Absorption: |
The taking in or soaking up of
one substance into the body of another by molecular or chemical action (as
tree roots absorb dissolved nutrients in the
soil). |
Absorption
Field: |
A system of properly sized and
constructed narrow trenches partially filled with a bed of washed gravel
or crushed stone into which perforated or open joint pipe is placed. The
discharge from the septic tank is distributed through these pipes into
trenches and surrounding soil.While seepage pits normally require less
land area to install, they should be used only where absorption fields are
not suitable and well-water supplies are not
endangered. |
Acid: |
A substance that dissolves in
water with the formation of hydrogen ions, contains hydrogen which may be
replaced by metals to form salt, and/or is
corrosive. |
Acidity: |
The capacity of water or
wastewater to neutralize bases. Acidity is expressed in milligrams per
liter of equivalent calcium carbonate. Acidity is not the same as
pH. |
Activated
sludge: |
Sludge particles produced in
raw or settled wastewater (primary effluent) by the growth of organisms
(including zoogleal bacteria) in aeration tanks in the presence of
dissolved oxygen. The term "activated" comes from the fact that the
particles are teeming with fungi, bacteria, and protozoa. Activated sludge
is different from primary sludge in that the sludge particles contain many
living organisms which can feed on the incoming
wastewater. |
Adsorption: |
The gathering of a gas,
liquid, or dissolved substance on the surface or interface zone of another
substance. |
ADP: |
Adenosine diphosphate. See
ATP. |
Aeration: |
The process of adding air to
water. In wastewater treatment, air is added to freshen wastewater and to
keep solids in suspension. |
Aeration
tank: |
The tank where raw or settled
wastewater is mixed with return sludge and aerated. This is the same as an
aeration bay, aerator, or reactor. |
Aerobe: |
An organism that requires free
oxygen for growth. |
Alkaline
substance: |
Chemical compounds in which
the basic hydroxide (OH-) ion is united with a metallic ion, such as
sodium hydroxide (NaOH) or potassium hydroxide (KOH). These substances
impart alkalinity to water and are employed for neutralization of acids.
Lime is the most commonly used alkaline material in wastewater
treatment. |
Alum: |
Astringent crystalline double
sulfate of an alkali. K2SO4AL2 (SO4)3 24H2O. Used in the processing of
pickles and as a flocking agent. Excess aluminum in the environment can be
hazardous. |
Ammonia
oxidation: |
Test drawn during
manufacturing process to evaluate the ammonia oxidation rate for the
nitrifiers. |
Ambient
temperature: |
Temperature of the
surroundings. |
Anaerobe: |
An organism that lives and
reproduces in the absence of dissolved oxygen, instead deriving oxygen
from the breakdown of complex substances. |
Anhydrous: |
Very dry. No water or dampness
is present. |
Anion: |
A negatively charged ion in an
electrolyte solution, attracted to the anode under the influence of a
difference in electrical potential. Chloride is an
anion. |
API
separator: |
A facility developed by the
Committee on Disposal or Refinery Wastes of the American Petroleum
Institute for separation of oil from wastewater in a gravity differential
and equipped with means for recovering the separated oil and removing
sludge |
Aseptic: |
Free from living germs of
disease, fermentation or putrefaction. |
Assimilate: |
To take in, similar to eating
food. |
Attached
growth processes: |
Wastewater treatment processes
in which the microorganisms and bacteria treating the wastes are attached
to the media in the reactor. The wastes being treated flow over the media.
Trickling filters, bio-towers, and RBCs are attached growth reactors.
These reactors can be used for removal of BOD, nitrification, and
denitrification. |
ATP: |
Adenosine triphosphate.
Chemical energy generated by substrate oxidations is conserved by
formation of high-energy compounds such as adenosine diphosphate (ADP) and
adenosine triphosphate (ATP) or compounds containing the thioester
bond |
Autotrophy: |
A unique form of metabolism
found only in bacteria. Inorganic compounds (e.g., NH3, NO2-, S2, and
Fe2+) are oxidized directly (without using sunlight) to yield energy. This
metabolic mode also requires energy for CO2 reduction, like
photosynthesis, but no lipid-mediated processes are involved. This
metabolic mode has also been called chemotrophy, chemoautotrophy, or
chemolithotrophy. |
AWT: |
Advanced Waste Treatment - any
process of water renovation that upgrades treated wastewater to meet reuse
requirements. |