Wastewater Test UPDATED ACTUAL Questions and CORRECT Answers

Wastewater Test UPDATED ACTUAL
Questions and CORRECT Answers
true - CORRECT ANSWER✔✔- true/false: for pump packing in water seal units, leakage
from the packing box is necessary to keep the packing cool and in good condition


feed sludges have been over thickened or concentrated, sludge pumps have been clogged by
debris contained within the raw feed sludge - CORRECT ANSWER✔✔- results in an
unintended decrease in the sludge pumping rate


septic sludge is accompanied by gas production which results in objectionable odors and
prevents proper thickening, nearby neighbors will call DEP and complain about foul odors
which may result in an inspection and possible notice of violation, septic supernatant from
the thickener is high in solids and when returned to the head of the plant will increase the
load on the treatment plant - CORRECT ANSWER✔✔- operational problems associated
with thickening septic sludge


true - CORRECT ANSWER✔✔- true/false: when you check the final clarifier you notice
large masses of sludge rising to the surface. If the sludge inventory is too high or if the DO
level in the settling tank is not high enough denitrification will occur. The oxygen associated
with the nitrate is removed, and the remaining nitrogen gas rises to the surface carrying solids
with it this could be the cause of your rising sludge


maintain the aeration at a balance at which nitrification in the aeration tanks is minimized,
increase the speed of the sludge collecting mechanism to decrease the time of settled sludge
retention, increase the rate of return activated sludge pumping from the clarifier - CORRECT
ANSWER✔✔- you determine that the cause of the rising sludge in your final clarifier is due
to denitrification, the following steps should be taken


the need to decrease wasting to increase sludge age. Straggler floc usually occurs when
MLSS is low - CORRECT ANSWER✔✔- when straggler floc is observed in the final
clarifier, while the effluent is otherwise clear it implies


sludge age is too high, the sludge may be overoxidized, turbulence in the aeration tank it too
high - CORRECT ANSWER✔✔- causes of pin floc

,lower the sludge age, reduce the turbulence in the aeration tank - CORRECT ANSWER✔✔-
options when addressing a pin floc problem


bulking sludge - CORRECT ANSWER✔✔- sludge that will not settle from the liquid


excessive filamentous bacteria that causes large but too light to settle floc. Think of this effect
as a parachute. When the parachute is closed tightly it will drop to the ground immediately.
When it is open it resists dropping., inadequate settling tank design, nutrient deficient influent
- CORRECT ANSWER✔✔- causes of bulking sludge


sludge settles and leaves a clear supernatant but SVi is high, low solids concentration in
return sludge, high sludge blanket in the final settling tank - CORRECT ANSWER✔✔-
characteristics of sludge bulking


true - CORRECT ANSWER✔✔- true/false: bulking sludge is generally caused by excessive
filaments


create a demand for more oxygen - CORRECT ANSWER✔✔- an increase in the influent
BOD will stimulate the microorganisms activity and growth rate. this increase in BOD will


true - CORRECT ANSWER✔✔- true/false: the volatile content of the mixed liquor
suspended solids represents a fractional percentage of MLSS


false - CORRECT ANSWER✔✔- true/false: as the water temperature drops the dissolved
oxygen transfer efficiency decreases


false - CORRECT ANSWER✔✔- true/false: high ammonia concentrations will create a low
dissolved oxygen demand


true - CORRECT ANSWER✔✔- true/false: a low dissolved oxygen concentration in the
aeration basin for an extended period may prevent nitrification and allow influent ammonia to
break through the treatment process and result in an ammonia violation

, true - CORRECT ANSWER✔✔- true/false: a low influent alkalinity concentration may
prevent nitrification and allow influent ammonia to break through the treatment process and
result in an ammonia violation


false - CORRECT ANSWER✔✔- true/false: the group of microorganisms capable of
surviving and functioning in the presence or absence of free oxygen is called autotrophic


true - CORRECT ANSWER✔✔- true/false: nitrification is the conversion of ammonia to
nitrite/nitrate by a special group of bacteria


true - CORRECT ANSWER✔✔- true/false: microorganisms in an anoxic environment use
combined oxygen from sources such as nitrates, nitrites, and sulfates to survive. no dissolved
oxygen is present


autotrophic - CORRECT ANSWER✔✔- what is the name for the bacteria that consumes
inorganic compounds such as ammonia and inorganic carbon as food sources?


bulking sludge - CORRECT ANSWER✔✔- what is the term used to describe a condition in
which activated sludge has poor settling characteristics and poor compaction? When this
occurs the sludge blanket in the secondary clarifier do not properly settle and solids
eventually escape the clarifiers and are discharge from the plant


anoxic conditions - CORRECT ANSWER✔✔- denitrification occurs under



rising/ floating sludge - CORRECT ANSWER✔✔- denitrification is the process in which
nitrite and nitrate are converted to nitrogen gas. When this occurs in the secondary clarifiers
you might observe


septic sludge - CORRECT ANSWER✔✔- any sludge that has become anaerobic and is
characterized by a foul odor is called


20-40% - CORRECT ANSWER✔✔- primary clarifiers should remove this percentage of
influent BOD