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Activated sludge is A. formed after s...

Activated sludge is
A. formed after sequential filtration and sedimentation in primary setting tank.
B. bacterial flocs settings after secondary treatment.
C. Passed into anaerobic sludge digester.

A

Only (A) is incorrect

B

Only (A) and (C) are incorrect

C

Only (B) and (C) are incorrect

D

(A) , (B) and (C) are incorrect

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question regarding activated sludge, we need to analyze each of the provided statements carefully. ### Step-by-Step Solution: 1. **Understanding Activated Sludge**: - Activated sludge refers to a mixture of microorganisms (mainly bacteria and fungi) that are used in the biological treatment of sewage. This process helps in breaking down organic matter present in the wastewater. 2. **Analyzing Statement A**: - "Activated sludge is formed after sequential filtration and sedimentation in the primary settling tank." - This statement is **incorrect**. The primary treatment involves physical processes like filtration and sedimentation, which do not involve the biological activity necessary for forming activated sludge. Activated sludge is formed during the secondary treatment process. 3. **Analyzing Statement B**: - "Bacterial flocs settling after secondary treatment." - This statement is **correct**. After the secondary treatment, the microbial flocs (bacterial aggregates) settle down, and this settled material is what we refer to as activated sludge. It contains the microorganisms that have digested the organic matter. 4. **Analyzing Statement C**: - "Passed into anaerobic sludge digester." - This statement is also **correct**. After the activated sludge is formed, it can be passed into an anaerobic sludge digester where further breakdown of organic matter occurs through anaerobic processes. 5. **Conclusion**: - Based on the analysis, Statement A is incorrect, while Statements B and C are correct. Therefore, the correct answer to the question is that activated sludge is associated with Statement B. ### Final Answer: **B. bacterial flocs settling after secondary treatment.**
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