1. What is lime and It's a calcium-containing mineral, typically containing hydroxides/oxides . Lime is
what is it used used to soften water [reduce hardness] and to precipitate phosphorous.
for?
2. What is alkalinity Alkalinity is the capability of water to neutralize acid without a significant change
and where does it in pH. In natural waters, it primarily comes from carbonate and bicarbonate ions
come from in nat- (CO3, HCO3), which react with free H+ ions to create carbonic acid (H2CO3).
ural waters?
3. What is the stan- The jar test is a test which models the three unit processes in the coagulation/pre-
dard jar test and cipitation sequence: flash mix, flocculation, and sedimentation. A set of six jars and
what does it stirrers with water samples are given varying doses of coagulants. The jars are then
model? stirred (high at 60rpm, then gently) and left to settle. Turbidity is measured to find
which coagulant dose was optimal for the given water sample.
4. What is the re- Available and actual chlorine are related by chlorine equivalent as Cl2available =
lationship among Cl2actual*Cl2eq. When the chlorine equivalent is 1.0, available and actual chlorine
chlorine equiva- are equal, otherwise, available chlorine is greater than actual chlorine.
lent, actual chlo-
rine, and avail-
able chlorine for
a chlorine com-
pound?
5. How is the evapo- Divide the annual lake evaporation by the annual pan evaporation.
ration pan coeffi-
cient defined?
6. What is the al- The alkalinity end point is defined as 4.5 pH, and is the pH to which a water sample
kalinity end point is titrated to in order to calculate its total alkalinity.
and when is it
used?
, FE Environmental Engineering Exam Flashcards
7. Titration When you slowly add a solution with a known concentration to a known volume
of another solution with an unknown concentration. It's done until the reaction
reaches neutralization: in a problem, they'll tell you what the concentration/pH etc.
is of the final solution.
8. Why do acids We define a pH of 7 as neutral. But what is pH? pH is defined as pH =
have a pH < 7, log_10(1/[H+]), that is, the log base 10 of the inverse of the molar concentration
while bases have of hydrogen ions.
a pH > 7?
An acid is a substance which produces H+ (hydrogen ions, i.e. a single proton). If
the value of [H+] is higher, then the value of log_10(1/[H+]) is lower. Therefore,
pH decreases as a substance increases in acidity.
9. How does salini- Salinity and evaporation rates are inversely proportional.
ty influence evap-
oration? As salinity increases, some of the salt molecules occupy space near the water
surface, reducing the area where water molecules can escape into the gas phase.
This lowers the vapor pressure, which reduces evaporation rates.
10. What is generally Attached-growth biological processes such as trickling filters and non-submerged
not considered rotating biological contactors (RBCs) are generally not as effective at biological
an advantage of nitrogen and phosphorus removal as is activated sludge. However, these processes
attached-growth offer advantages of improved solids settling and thickening, lower energy require-
biological ments, better resistance to shock loading, less operation problems, and lower
processes, such maintenance costs.
as trickling filters
and
non-submerged
RBCs, when
compared to
activated sludge?
11.
, FE Environmental Engineering Exam Flashcards
What is the Rippl The Rippl method is a reservoir sizing method where the size of the reservoir is
method and equal to the maximum cumulative difference between inflows and outflows. The
what is a Ripply Rippl diagram shows the cumulative net volume in the reservoir.
diagram/reser-
voir mass
diagram?
12. How is dissolved Dissolved oxygen decreases with increasing temperature and decreases with in-
oxygen affect- creasing salinity.
ed by temper-
ature, pressure, It increases with increasing pressure.
and salinity?
Salinity results in a decrease in oxygen solubility because the NaCl molecules attract
the H2O molecules, which reduce the attraction of the H2O molecules with the
dissolved oxygen (O2) molecules.
13. Isohyets Lines of equal precipitation (think "hyetograph")
14. What are the Class I: high beneficial use, located in a potentially vulnerable setting
EPA groundwater
classes? Class II: current and potential sources of drinking water and have other beneficial
uses
Class III: Not considered a potential source of drinking water and of limited
beneficial use.
15. What is the Unit hydrographs are based on actual storm events, while synthetic unit hydro-
difference be- graphs are used when no storm data are available.
tween unit hydro-
graphs and syn-
thetic unit hydro-
graphs?
16.