Trickling filters MCQ – Environmental Engineering

1. Trickling filters are used to remove

  1. colloidal organic matter
  2. dissolved inorganic solid
  3. pathogenic bacteria
  4. none of these
Answer
Answer. a

2. A trickling filter is primarily a

  1. straining process to remove suspended solids from sewage
  2. biological oxidation process to remove BOD from sewage
  3. straining process to remove turbidity from water
  4. straining process to remove bacteria from water
Answer
Answer. b

3. The usual rate of hydraulic loading on high rate Trickling Filter is

  1. 1-2 m3/m2 day
  2. 2-5 m3/m2 day
  3. 10-30 m3/m2 day
  4. 5- 10 m3/m2 day
Answer
Answer. c

4. In a high-rate trickling filter, the problem of ponding can be solved by

  1. Flooding and raking
  2. Chlorination and supply of air
  3. Raking and chlorination
  4. Flooding and supply of air
Answer
Answer. c

5. Trickling filter sizing criteria is based on

  1. Overflow rate
  2. Hydraulic loading
  3. Flow rate
  4. Detention time
Answer
Answer. b

6. In tricking filter, what is the phenomenon of losing slime layer called?

  1. Sloughing
  2. Slugging
  3. Sliming
  4. Slashing
Answer
Answer. a

7. The recirculation factor in a low rate trickling filter is

  1. 0
  2. 1
  3. 10
  4. 100
Answer
Answer. b

8. The organic loading in a trickling filter is measured in

  1. m3/day
  2. gm/m2/day
  3. kg/hectare-meter/day
  4. kg/hectare/day
Answer
Answer. c

9. The secondary treatment of sewage is carried out by the use of

  1. Screens
  2. Grit chambers
  3. Trickling filters
  4. Chlorinators
Answer
Answer. c

10. The distributing arms of large trickling filter units are rotated at speed of

  1. (1/3-1/2) r.p.m.
  2. 1-2 r.p.m.
  3. 2-4 r.p.m.
  4. None of these
Answer
Answer. a

11. A reactor, in which the surface area for growth of biofilm is provided by randomly packed solid forms is called

  1. activated sludge reactor
  2. tricking filter
  3. stabilization pond
  4. none of these
Answer
Answer. b

12. The hydraulic loading rate of high rate trickling filter, including recirculation, in m3/m2/day is

  1. 1-4
  2. 10-40
  3. 40-100
  4. 100-200
Answer
Answer. b

13. The removal of dissolved organic matter occurs in

  1. Slow sand filters
  2. Trickling filters
  3. Rapid sand filters
  4. Dual media filters
Answer
Answer. b

14. The secondary treatment of sewage is done by the use of

  1. Grit chamber
  2. Screens
  3. Trickling filters
  4. Chlorinators
Answer
Answer. c

15. Sloughing phenomena is observed in

  1. oxidation pond
  2. activated sludge process
  3. trickling filter
  4. extended aeration process
Answer
Answer. c

16. Trickling filter removes BOD5 up to

  1. 60 to 70%
  2. 50 to 60%
  3. 80 to 90%
  4. 70 to 80%
Answer
Answer. d

17. The efficiency of biochemical oxygen demand (BOD) removal in trickling filter is

  1. 98%
  2. 65%
  3. 56%
  4. 85%
Answer
Answer. d