Microbes in Sewage Treatment: NEET MCQs with Answers

9 free questions on Microbes in Sewage Treatment for NEET (UG), starting with previous-year NEET and AIPMT questions. Try each one, then tap Show answer for the answer and a short explanation.

Practise all 48 Microbes in Sewage Treatment questions free Take a free timed test

Question 1

Previous-year question
Which of the following is put into the anaerobic sludge digester for further sewage treatment? [NEET 2020]
  1. Floating debris
  2. Effluents of primary treatment
  3. Activated sludge
  4. Primary sludge
Show answer
Answer: (C) Activated sludge
Explanation: The bulk of the activated sludge from the settling tank is pumped into anaerobic sludge digesters, where anaerobic bacteria digest it and produce biogas.

Question 2

Previous-year question
Which of the following in sewage treatment removes suspended solids? [NEET 2017]
  1. Secondary treatment
  2. Primary treatment
  3. Sludge treatment
  4. Tertiary treatment
Show answer
Answer: (B) Primary treatment
Explanation: Suspended and floating solids are removed physically during primary treatment by filtration and sedimentation, leaving the primary effluent for biological treatment.

Question 3

Previous-year question
Select the correct statement from the following. [AIPMT 2010]
  1. Biogas is produced by the activity of aerobic bacteria on animal waste
  2. Methanobacterium is an aerobic bacterium found in the rumen of cattle
  3. Biogas, commonly called gobar gas, is pure methane
  4. Activated sludge sediment in settlement tanks of a sewage treatment plant is a rich source of aerobic bacteria
Show answer
Answer: (D) Activated sludge sediment in settlement tanks of a sewage treatment plant is a rich source of aerobic bacteria
Explanation: Activated sludge is the sediment of the settlement tanks and is a rich source of aerobic bacteria used in treating sewage and industrial waste water. Biogas is produced anaerobically, Methanobacterium is anaerobic, and gobar gas is a mixture of methane with CO₂ and traces of other gases.

Question 4

Previous-year question
Secondary sewage treatment is mainly a [AIPMT 2011]
  1. mechanical process
  2. chemical process
  3. biological process
  4. physical process
Show answer
Answer: (C) biological process
Explanation: Secondary sewage treatment is a biological process in which microorganisms such as bacteria and protozoa break down the organic matter and remove nutrients from the waste water after the primary stage. After the biological process the water is chlorinated and recycled.

Question 5

Previous-year question
Which of the following is mainly produced by the activity of anaerobic bacteria on sewage? [AIPMT 2011]
  1. Propane
  2. Mustard gas
  3. Marsh gas
  4. Laughing gas
Show answer
Answer: (C) Marsh gas
Explanation: Marsh gas, which is methane, is mainly produced by the activity of anaerobic bacteria on sewage in the sludge digester.

Question 6

Previous-year question
During sewage treatment, biogases are produced which include [NEET 2013]
  1. methane, hydrogen sulphide and carbon dioxide
  2. methane, oxygen and hydrogen sulphide
  3. hydrogen sulphide, methane and sulphur dioxide
  4. hydrogen sulphide, nitrogen and methane
Show answer
Answer: (A) methane, hydrogen sulphide and carbon dioxide
Explanation: Biogas produced during sewage treatment includes methane, hydrogen sulphide and carbon dioxide. It is generated by microbial activity in the anaerobic sludge digester and may be used as a fuel.

Question 7

Previous-year question
What gases are produced in anaerobic sludge digesters? [AIPMT 2014]
  1. Methane and CO₂ only
  2. Methane, hydrogen sulphide and CO₂
  3. Methane, hydrogen sulphide and O₂
  4. Hydrogen sulphide and CO₂
Show answer
Answer: (B) Methane, hydrogen sulphide and CO₂
Explanation: Methane, hydrogen sulphide and carbon dioxide are produced in anaerobic sludge digesters. These biogases are generated by the activity of a group of bacteria called methanogens.
Doing well? Create a free account to take timed tests on this topic and see your weak areas.

Question 8

Previous-year question
Which of the following steps in sewage treatment removes suspended solids? [NEET 2017]
  1. Tertiary treatment
  2. Secondary treatment
  3. Primary treatment
  4. Sludge treatment
Show answer
Answer: (C) Primary treatment
Explanation: Suspended solids are removed during primary treatment, which is also known as physical treatment. It consists of shredding, churning, screening and sedimentation, with sequential filtration removing the floating debris.

Question 9

Previous-year question
Which one of the following is put into an anaerobic sludge digester for further sewage treatment? [NEET 2020]
  1. Primary sludge
  2. Floating debris
  3. Effluents of primary treatment
  4. Activated sludge
Show answer
Answer: (D) Activated sludge
Explanation: The sediment in the settling tank is called activated sludge. A small part of it is pumped back into the aeration tank to serve as the inoculum, while the remaining major part is pumped into large tanks called anaerobic sludge digesters.

Want more Microbes in Sewage Treatment questions?

E-GYAN NIDHI has 48 questions on this topic and 63,000+ in total, all free: timed CBT tests, NEET marking and instant analysis.

Register free Free Sunday Mock Test

More topics in Biology and Human Welfare

↑