Sewage is broken down in

Options

A. Primary treatment
B. Secondary treatment
C. Tertiary treatment
D. All of the above

Answer

To solve the question "Sewage is broken down in," we need to analyze the different treatment processes involved in sewage treatment. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Understanding Sewage Treatment**:
- Sewage treatment involves a series of processes to remove contaminants from wastewater, making it safe for discharge into the environment or for reuse.

2. **Identifying Treatment Stages**:
- There are three main stages of sewage treatment:
- **Primary Treatment**: This involves the physical removal of solids through filtration and sedimentation.
- **Secondary Treatment**: This is a biological process where microorganisms decompose organic matter in the sewage.
- **Tertiary Treatment**: This involves advanced chemical and physical processes to remove remaining contaminants.

3. **Analyzing the Options**:
- **Option A: Primary Treatment**: This stage primarily focuses on the physical removal of solids and does not break down sewage.
- **Option B: Secondary Treatment**: This stage is where the actual breakdown of sewage occurs through microbial action, making it a key process in sewage treatment.
- **Option C: Tertiary Treatment**: This stage is more about polishing the effluent and removing remaining impurities, not primarily breaking down sewage.
- **Option D: All of the Above**: While all stages are involved in sewage treatment, only the secondary treatment is specifically responsible for breaking down sewage.

4. **Conclusion**:
- Based on the analysis, the correct answer to the question "Sewage is broken down in" is **Option B: Secondary Treatment**.