Environmental Engineering Multiple Choice Questions on “Construction of Imhoff Tank”.
1. Which of the following is represented by C in the following figure?
Figure: Imhoff tank
a) Outlet
b) Digestion chamber
c) Gas chamber
d) Sedimentation chamber
Answer: b
Clarification: C represents the digested chamber. It is placed in the lower section of Imhoff tank.
2. In which of the following, the settling of solids takes place in the following figure?
Figure: Imhoff tank
a) Outlet
b) Digestion chamber
c) Gas chamber
d) Sedimentation chamber
Answer: d
Clarification: The settling of solids takes place at the sedimentation chamber. It is represented by D in the above figure.
3. The maximum flow through the period at D in the following figure?
Figure: Imhoff tank
a) 0.3m/min
b) 0.4m/min
c) 0.8m/min
d) 0.9m/min
Answer: a
Clarification: The maximum flow through the period at D is 0.3m/min and its design depth should be between 3 to 3.5 m.
4. The sludge is digested in which of the following?
Figure: Imhoff tank
a) Outlet
b) Sedimentation chamber
c) Gas chamber
d) Digestion chamber
Answer: d
Clarification: The sludge is digested in the digestion chamber. Its minimum design capacity is 57 liters per person.
5. The gas chamber in the below figure is represented by _____________
Figure: Imhoff tank
a) A
b) E
c) B
d) C
Answer: b
Clarification: The gas chamber is represented by the E in the figure. It is located at the sides of the Imhoff tank.
6. The sewage comes in the Imhoff tank through which of the following?
Figure: Imhoff tank
a) A
b) B
c) C
d) D
Answer: a
Clarification: A represents the inlet through which the sewage enters the Imhoff tank.
7. The detention period of the sedimentation chamber of an Imhoff tank is?
Figure: Imhoff tank
a) 30 seconds
b) 30 minute
c) 1 hour
d) 2 hours
Answer: d
Clarification: The detention period of the sedimentation chamber of an Imhoff tank is 2 hours. It is represented by D as shown in the figure.
8. B in the following figure is represented by ____________
Figure: Imhoff tank
a) Outlet
b) Sedimentation chamber
c) Gas chamber
d) Digestion chamber
Answer: a
Clarification: B represents the outlet of Imhoff tank. It carries the partially treated sewage.
9. Which of the following is called a scum chamber in the following figure?
Figure: Imhoff tank
a) Settling chamber
b) Sedimentation chamber
c) Gas chamber
d) Digestion chamber
Answer: c
Clarification: Gas chamber is also called a scum chamber. The minimum design width of the gas chamber is 60cm.