Before You Begin
Question #47699
The Question
In a municipal sewage treatment plant, a mechanical failure causes the primary settling tanks to be bypassed, pumping raw, unfiltered sewage directly into the aeration tanks. Which of the following represents the most critical biological consequence of this bypass on the secondary treatment process?
Options
- A.
Inorganic debris will physically mask microbial surfaces, preventing the formation of the bacterial-fungal filamentous matrix (flocs) and stalling the reduction of Biochemical Oxygen Demand (BOD).
- B.
The high concentration of primary sludge will rapidly deplete dissolved oxygen, immediately shifting the aeration tank to an anaerobic state and promoting methanogen growth.
- C.
The Biochemical Oxygen Demand (BOD) of the effluent will decrease at an accelerated rate due to the sudden hyper-availability of organic substrates for aerobic microbes.
- D.
Primary sludge will act as an anaerobic inoculum, causing an overproliferation of anaerobic bacteria that competitively exclude the aerobic flocs.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Flocs_Formation|Biotic_Interactions|Activated_Sludge_Inoculum
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that 'Secondary treatment reduces BOD using flocs' but fail to understand the physical prerequisites for floc formation.
The common misconception is treating primary and secondary treatments as functionally independent steps, rather than sequential dependencies where the failure to remove physical debris actively inhibits the biological matrix formation required for the next step.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Microbes in Human Welfare - Class 12 |
| Concept | Flocs Formation |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |