Activated Sludge Plant MCQs : This section focuses on the "Activated Sludge Plant". These Multiple Choice Questions (MCQs) should be practiced to improve the Activated Sludge Plant skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
Question 1
_________ is defined as a volume in ml occupied by 1 gram of solid in the mixed liquor after 30 minutes of settling.
A. BOD loading
B. Suspended solid volume
C. Sludge volume index
D. Organic loading
Question 2
_________ is the time at which sewage is detained in the aeration tank.
A. Average time
B. Detention time
C. Aeration period
D. Reaeration period
Question 3
BOD of sewage is dependent on food to microorganism ratio.
A. True
B. False
Question 4
The design value of food to microorganism ratio in the tapered aeration sludge process is ___________
A. 0.1
B. 0.2
C. 0.4
D. 0.8
Question 5
The maximum aeration period for a conventional activated sludge system is ___________
A. 2 hours
B. 3 hours
C. 4 hours
D. 6 hours
Question 6
The maximum BOD removal efficiency of the Step aeration process of the activated sludge system is ___________
A. 92%
B. 80%
C. 99%
D. 78%
Question 7
The organic loading in an activated sludge plant is defined as ___________
A. Mass of BOD per day/Volume of the aeration tank
B. Volume of aeration tank/Mass of BOD per day
C. The mass of BOD per day/Volume of secondary clarifier
D. Aeration period * Volume of aeration tank
Question 8
Which of the following activated sludge process has minimum food to microorganism ratio?
A. Extended aeration
B. Step aeration
C. Modified aeration
D. Conventional
Question 9
Which of the following is the correct expression of the aeration period in hours?
A. V/Q
B. 24V/Q
C. V/24Q
D. Q/V
Question 10
Which of the following sludge process has maximum aeration period?
A. Conventional process
B. Extended process
C. Step aeration process
D. Tapered aeration
Question 11
Which of the following has minimum hydraulic retention time?
A. Conventional process
B. Extended process
C. Modified aeration process
D. Complete mix process