Engineering Questions with Answers - Multiple Choice Questions

Environmental Engineering MCQ – Biological Characteristics of Waste Water

1 - Question

Which of the following is an end product formed from both the aerobic and anaerobic decomposition of organic matter?
a) NO3
b) CH4
c) H2S
d) CO2

View Answer

Answer: d
Explanation: Carbon dioxide is formed due to the oxidation and reduction of organic matter by aerobic and anaerobic bacteria respectively.




2 - Question

The aerobic decomposition of carbonaceous organic matter gives __________
a) Nitrites and water
b) Carbon dioxide and water
c) Sulfates and water
d) Nitrogen and Ammonia

View Answer

Answer: b
Explanation: Carbonaceous organic matter (oxidation by aerobic bacteria) —–> CO2 + H2O + Energy.




3 - Question

BOD of wastewater having aerobic oxidation is more than that, having anaerobic oxidation.
a) True
b) False

View Answer

Answer: b
Explanation: The BOD of wastewater where oxidation of organic matter takes place is very less in comparison to that formed by anaerobic oxidation, where BOD of 5000ppm can be formed.




4 - Question

The aerobic decomposition of nitrogenous organic matter gives __________
a) Nitrites and water
b) Carbon dioxide and water
c) Nitrates and ammonia
d) Nitrogen and ammonia

View Answer

Answer: c
Explanation: Nitrogenous organic matter (oxidation by aerobic bacteria) —–> NO3 + NH3 + Energy.




5 - Question

Methane is formed due to the reduction of __________
a) Nitrates
b) Sulfates
c) Carbon dioxide
d) Organic acids

View Answer

Answer: d
Explanation: Organic acids (oxidation by anaerobic bacteria) —–> CH4 + CO2 + Energy.




6 - Question

Which of the following is formed due to the anaerobic decomposition of carbonaceous organic matter?
a) Nitrites
b) Carbon dioxide
c) Water
d) Nitrogen

View Answer

Answer: b
Explanation: Carbonaceous organic matter (reduction by anaerobic bacteria) —–> CO2 + Energy.




7 - Question

Which of the following is formed due to the reduction of sulfurous organic matter?
a) Hydrogen sulfide
b) Hydrochloric acid
c) Sulfuric acid
d) Sulfur dioxide

View Answer

Answer: a
Explanation: Sulfurous organic matter (reduction by anaerobic bacteria) —–> H2S + Energy.




8 - Question

Partially oxidized sewage contains __________
a) Nitrites and Nitrates
b) Nitrates and sulfur
c) Sulfates and nitrates
d) Nitrites and sulfur

View Answer

Answer: d
Explanation: Partially oxidized sewage contains nitrites and sulfur whereas fully oxidized sewage contains nitrates and sulfates.




9 - Question

The aerobic decomposition of sulfurous organic matter gives __________
a) Nitrites and water
b) Carbon dioxide and water
c) Sulfates and water
d) Nitrogen and Ammonia

View Answer

Answer: c
Explanation: Sulfurous organic matter (oxidation by aerobic bacteria) —–> SO4 + Energy.




10 - Question

The energy released during the aerobic oxidation of organic matter is _____ kilo calories.
a) 26
b) 254
c) 360
d) 484

View Answer

Answer: d
Explanation: Large amount of energy is released during the oxidation of organic matter with a magnitude between 484 and 674 kilo calories.




11 - Question

The decomposition of nitrogenous organic matter in the absence of oxygen gives __________
a) Nitrites and water
b) Carbon dioxide and water
c) Nitrates and ammonia
d) Nitrogen, ammonia and organic acids

View Answer

Answer: d
Explanation: Nitrogenous organic matter (reduction by anaerobic bacteria) —–> N2 + NH3 + organic acids + Energy.




12 - Question

Which of the following is formed from the anaerobic oxidation of organic matter?
a) NO3
b) SO4
c) H2S
d) NH2

View Answer

Answer: c
Explanation: H2S is formed from the anaerobic oxidation of sulfurous organic matter.




13 - Question

The number of stages required for the completion of aerobic oxidation is __________
a) 1
b) 2
c) 3
d) 4

View Answer

Answer: a
Explanation: Aerobic oxidation gets completed only in single step, whereas anaerobic oxidation gets completed in two steps.




14 - Question

 Which of the following is formed from oxidation of organic matter in the presence of oxygen?
a) NO3
b) SO4
c) H2S
d) NH2

View Answer

Answer: a
Explanation: NO3 is formed due to the aerobic decomposition of nitrogenous organic matter.




15 - Question

The energy released during the anaerobic oxidation of organic matter is _____ kilo calories.
a) 26
b) 254
c) 360
d) 484

View Answer

Answer: a
Explanation: Small amount of energy is released during the anaerobic oxidation in comparison to aerobic oxidation of organic matter with a magnitude of 26 kilo calories.

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