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With reference to microbes in sewage treatment, consider the following statements:
1. ‘Flocs’ are masses of aerobic bacteria that are used for consuming the organic matter in the sewage waste.
2. Flocs increase the Biological Oxygen Demand of the sewage.
3. ‘Activated sludge’ is free from bacteria and other microorganisms.
Which of the statements given above is/are Correct?
- a)1 only
- b)1 and 2 only
- c)2 only
- d)1, 2 and 3
Correct answer is option 'A'. Can you explain this answer?
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Most Upvoted Answer
With reference to microbes in sewage treatment, consider the followin...
Option (a) is the correct answer. Sewage is treated in sewage treatment plants (STPs) to make it less polluting. Treatment
of waste water is done by the heterotrophic microbes naturally present in the sewage. This treatment is carried out in two stages: Primary treatment; Secondary treatment or Biological treatment. Primary treatment : These treatment steps basically involve physical removal of particles – large and small – from the sewage through filtration and sedimentation. These are removed in stages; initially, floating debris is removed by sequential filtration. All solids that settle form the primary sludge, and the supernatant forms the effluent. The effluent from the primary settling tank is taken for secondary treatment.
The primary effluent is passed into large aeration tanks where it is constantly agitated mechanically and air is pumped into it. associated with fungal filaments to form mesh like structures). While growing, these microbes consume the major part of the organic matter in the effluent.
Statement 2 is incorrect. This significantly reduces the BOD (biochemical oxygen demand) of the effluent. BOD refers to the amount of oxygen that would be consumed if all the organic matter in one liter of water were oxidised by bacteria. The sewage water is treated until the BOD is reduced. Statement 3 is incorrect. Once the BOD of sewage or wastewater is reduced significantly, the effluent is then passed into a settling tank where the bacterial ‘flocs’ are allowed to sediment. This sediment is called activated sludge.
A small part of the activated sludge is pumped back into the aeration tank to serve as the inoculum. The remaining major part of the sludge is pumped into large tanks called anaerobic sludge digesters. Here, other kinds of bacteria, which grow anaerobically, digest the bacteria and fungi in the sludge. During this digestion, bacteria produce a mixture of gases such as methane, hydrogen sulphide and carbon dioxide. These gases form biogas and can be used as a source of energy as it is inflammable. The effluent from the secondary treatment plant is generally released into natural water bodies like rivers and streams.
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Community Answer
With reference to microbes in sewage treatment, consider the followin...
Understanding Microbes in Sewage Treatment
Sewage treatment involves various microbial processes that help in breaking down organic matter. Here’s an analysis of the statements provided:
Statement 1: Flocs and Aerobic Bacteria
- Flocs are indeed masses of aerobic bacteria.
- These bacteria play a crucial role in consuming organic matter present in sewage waste.
- This statement is correct.
Statement 2: Flocs and Biological Oxygen Demand (BOD)
- The presence of flocs does not increase the Biological Oxygen Demand (BOD); rather, they help in reducing BOD.
- BOD measures the amount of oxygen required by aerobic microorganisms to decompose organic material.
- Thus, as flocs consume organic waste, they lower the BOD, making this statement incorrect.
Statement 3: Activated Sludge
- Activated sludge is a mixture that contains a high concentration of bacteria and other microorganisms.
- It is not free from bacteria; in fact, it consists mainly of these microbes that facilitate the breakdown of organic materials.
- Therefore, this statement is also incorrect.
Conclusion
- Only Statement 1 is correct, making the answer option 'A'.
In summary, while flocs are vital in sewage treatment for consuming organic matter, they do not increase BOD, and activated sludge is rich in bacteria, not devoid of them. Understanding these aspects is essential for effective sewage treatment processes.
Sewage treatment involves various microbial processes that help in breaking down organic matter. Here’s an analysis of the statements provided:
Statement 1: Flocs and Aerobic Bacteria
- Flocs are indeed masses of aerobic bacteria.
- These bacteria play a crucial role in consuming organic matter present in sewage waste.
- This statement is correct.
Statement 2: Flocs and Biological Oxygen Demand (BOD)
- The presence of flocs does not increase the Biological Oxygen Demand (BOD); rather, they help in reducing BOD.
- BOD measures the amount of oxygen required by aerobic microorganisms to decompose organic material.
- Thus, as flocs consume organic waste, they lower the BOD, making this statement incorrect.
Statement 3: Activated Sludge
- Activated sludge is a mixture that contains a high concentration of bacteria and other microorganisms.
- It is not free from bacteria; in fact, it consists mainly of these microbes that facilitate the breakdown of organic materials.
- Therefore, this statement is also incorrect.
Conclusion
- Only Statement 1 is correct, making the answer option 'A'.
In summary, while flocs are vital in sewage treatment for consuming organic matter, they do not increase BOD, and activated sludge is rich in bacteria, not devoid of them. Understanding these aspects is essential for effective sewage treatment processes.
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With reference to microbes in sewage treatment, consider the following statements:1. ‘Flocs’ are masses of aerobic bacteria that are used for consuming the organic matter in the sewage waste.2. Flocs increase the Biological Oxygen Demand of the sewage.3. ‘Activated sludge’ is free from bacteria and other microorganisms.Which of the statements given above is/are Correct?a)1 onlyb)1 and 2 onlyc)2 onlyd)1, 2 and 3Correct answer is option 'A'. Can you explain this answer?
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With reference to microbes in sewage treatment, consider the following statements:1. ‘Flocs’ are masses of aerobic bacteria that are used for consuming the organic matter in the sewage waste.2. Flocs increase the Biological Oxygen Demand of the sewage.3. ‘Activated sludge’ is free from bacteria and other microorganisms.Which of the statements given above is/are Correct?a)1 onlyb)1 and 2 onlyc)2 onlyd)1, 2 and 3Correct answer is option 'A'. Can you explain this answer? for UPSC 2024 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about With reference to microbes in sewage treatment, consider the following statements:1. ‘Flocs’ are masses of aerobic bacteria that are used for consuming the organic matter in the sewage waste.2. Flocs increase the Biological Oxygen Demand of the sewage.3. ‘Activated sludge’ is free from bacteria and other microorganisms.Which of the statements given above is/are Correct?a)1 onlyb)1 and 2 onlyc)2 onlyd)1, 2 and 3Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for UPSC 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for With reference to microbes in sewage treatment, consider the following statements:1. ‘Flocs’ are masses of aerobic bacteria that are used for consuming the organic matter in the sewage waste.2. Flocs increase the Biological Oxygen Demand of the sewage.3. ‘Activated sludge’ is free from bacteria and other microorganisms.Which of the statements given above is/are Correct?a)1 onlyb)1 and 2 onlyc)2 onlyd)1, 2 and 3Correct answer is option 'A'. Can you explain this answer?.
With reference to microbes in sewage treatment, consider the following statements:1. ‘Flocs’ are masses of aerobic bacteria that are used for consuming the organic matter in the sewage waste.2. Flocs increase the Biological Oxygen Demand of the sewage.3. ‘Activated sludge’ is free from bacteria and other microorganisms.Which of the statements given above is/are Correct?a)1 onlyb)1 and 2 onlyc)2 onlyd)1, 2 and 3Correct answer is option 'A'. Can you explain this answer? for UPSC 2024 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about With reference to microbes in sewage treatment, consider the following statements:1. ‘Flocs’ are masses of aerobic bacteria that are used for consuming the organic matter in the sewage waste.2. Flocs increase the Biological Oxygen Demand of the sewage.3. ‘Activated sludge’ is free from bacteria and other microorganisms.Which of the statements given above is/are Correct?a)1 onlyb)1 and 2 onlyc)2 onlyd)1, 2 and 3Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for UPSC 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for With reference to microbes in sewage treatment, consider the following statements:1. ‘Flocs’ are masses of aerobic bacteria that are used for consuming the organic matter in the sewage waste.2. Flocs increase the Biological Oxygen Demand of the sewage.3. ‘Activated sludge’ is free from bacteria and other microorganisms.Which of the statements given above is/are Correct?a)1 onlyb)1 and 2 onlyc)2 onlyd)1, 2 and 3Correct answer is option 'A'. Can you explain this answer?.
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With reference to microbes in sewage treatment, consider the following statements:1. ‘Flocs’ are masses of aerobic bacteria that are used for consuming the organic matter in the sewage waste.2. Flocs increase the Biological Oxygen Demand of the sewage.3. ‘Activated sludge’ is free from bacteria and other microorganisms.Which of the statements given above is/are Correct?a)1 onlyb)1 and 2 onlyc)2 onlyd)1, 2 and 3Correct answer is option 'A'. Can you explain this answer?, a detailed solution for With reference to microbes in sewage treatment, consider the following statements:1. ‘Flocs’ are masses of aerobic bacteria that are used for consuming the organic matter in the sewage waste.2. Flocs increase the Biological Oxygen Demand of the sewage.3. ‘Activated sludge’ is free from bacteria and other microorganisms.Which of the statements given above is/are Correct?a)1 onlyb)1 and 2 onlyc)2 onlyd)1, 2 and 3Correct answer is option 'A'. Can you explain this answer? has been provided alongside types of With reference to microbes in sewage treatment, consider the following statements:1. ‘Flocs’ are masses of aerobic bacteria that are used for consuming the organic matter in the sewage waste.2. Flocs increase the Biological Oxygen Demand of the sewage.3. ‘Activated sludge’ is free from bacteria and other microorganisms.Which of the statements given above is/are Correct?a)1 onlyb)1 and 2 onlyc)2 onlyd)1, 2 and 3Correct answer is option 'A'. Can you explain this answer? theory, EduRev gives you an
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