Ecosystem |
(Environmental Engineering) An organism or group of organisms and their surroundings. The boundary of an ecosystem may be arbitrarily chosen to suit the area of interest or study. |
Electronegativity |
(Environmental Engineering) The potential of an atom to attract electrons when the atom is bonded in a compound. The scale is 0 to 4 with 0 being the most electropositive (low attraction) and 4 being the most electronegative (high attraction). |
Elementary reaction |
(Environmental Engineering) A reaction in which the rate expression corresponds to the stoichiometric equation. |
Epilimnion |
(Environmental Engineering) The top layer of a lake. |
Ethers |
(Environmental Engineering) An organic compound which has two hydrocarbon groups bound by an interior oxygen atom. The general formula is R'-O-R". |
Eucaryotic organisms |
(Environmental Engineering) Organisms which possess a nuclear membrane. This includes all known organisms except viruses and bacteria. |
Facultative |
(Environmental Engineering) A group of microorganisms which prefer or preferentially use molecular oxygen when available, but are capable of suing other pathways for energy and synthesis if molecular oxygen is not available. |
Fermentation |
(Environmental Engineering) Energy production without the benefit of oxygen as a terminal electron acceptor, i.e. oxidation in which the net effect is one organic compound oxidizing another. See respiration. |
Fixed suspended solids |
(Environmental Engineering) (FSS) is the matter remaining from the suspended solids analysis which will not burn at 550°C. It represents the non-filterable inorganic residue in a sample. |
Flocculant settling |
(Environmental Engineering) Settling in which particle concentrations are sufficiently high that particle agglomeration occurs. This results in a reduction in the number of particles and an increase in average particle mass. As agglomeration occurs higher settling velocities result. |