Oxidation Pond MCQ – Environmental Engineering

1. Consider the following statements regarding waste stabilization ponds:

  1. The pond has a symbiotic process of waste stabilization through algae on one hand and bacteria on the other
  2. The oxygen in the pond is provided by algae through photosynthesis
  3. The detention period is of the order of two to three days
  4. The bacteria which develop in the pond are aerobic bacteria

Which of the above statements are correct?

  1. i and ii only
  2. ii and iii only
  3. iii and iv only
  4. i and iv only
Answer
Answer. c

2. For mechanically aerated lagoons, less detention time and areas are required because

  1. it is more loaded than the oxidation ponds
  2. these ponds are wider than the oxidation ponds
  3. these ponds are deeper than the oxidation ponds
  4. it is less loaded than the oxidation ponds
Answer
Answer. c

3. In an oxidation pond, the sewage is treated by

  1. Aerobic bacteria
  2. Anaerobic bacteria
  3. Dual action of aerobic bacteria and algae
  4. Sedimentation
Answer
Answer. c

4. The detention period for oxidation ponds is usually kept as

  1. 24 hours
  2. 4-8 hours
  3. 10-15 hours
  4. 3 months
Answer
Answer. d

5. From amongst the following sewage treatment option, largest land requirements for a given discharge will be needed for

  1. Oxidation ditch
  2. Oxidation pond
  3. Aerobic pond
  4. Anaerobic pond
Answer
Answer. b

6. In the oxidation ditch, the excess sludge is taken to

  1. anaerobic digester
  2. aerobic digester
  3. drying digester
  4. incinerator
Answer
Answer. c

7. In the design and operation of an oxidation pond which of these factors are important?

  1. depth and shape
  2. surface area
  3. inlets and outlets
  4. all of these
Answer
Answer. d

8. The area of oxidation ponds is determined on the basis of the following approximate rules

  1. 500 persons to one acre of pond area
  2. 1000 persons to one acre of pond area
  3. 1500 persons to one acre of pond area
  4. 2000 persons to one acre of pond area
Answer
Answer. d

9. From the following sewage treatment options, the largest land for a given discharge will be needed for

  1. Trickling filter
  2. Anaerobic pond
  3. Oxidation ditch
  4. Oxidation pond
Answer
Answer. d

10. The growth of algae is useful in

  1. sedimentation tank
  2. slow sand filter
  3. oxidation pond
  4. sludge digestion tank
Answer
Answer. c

11. Sewage treatment in a oxidation pond is done by

  1. algal photosynthesis
  2. bacterial oxidation
  3. algal-bacterial symbiosis
  4. chemical oxidation
Answer
Answer. c

12. For sewage treatment using an oxidation pond, when it gets overloaded, a chemical that is added to stimulate the algae growth is

  1. sodium chloride
  2. sodium nitrate
  3. bleaching hydroxide
  4. calcium hydroxide
Answer
Answer. b

13. Identify the waste water treatment unit which use both aerobic and anaerobic mechanism for the removal of organic matter?

  1. Trickling filter
  2. Activated sludge process
  3. Oxidation ditch
  4. Stabilization ponds
Answer
Answer. d

14. The maximum efficiency of BOD removal is achieved in

  1. Aerated lagoons
  2. Trickling filters
  3. Digestion tank
  4. Oxidation ditch
Answer
Answer. d

15. Shallow ponds in which dissolved oxygen is present at all depth are called

  1. Aerobic lagoons
  2. Aerobic ponds
  3. Facultative lagoons
  4. Facultative ponds
Answer
Answer. b

16. The maximum BOD removal efficiency of an Oxidation pond is

  1. 90%
  2. 95%
  3. 70%
  4. 80%
Answer
Answer. b

17. The waste stabilization ponds can be

  1. anaerobic
  2. aerobic
  3. facultative
  4. all of the above
Answer
Answer. d