Water with a dissolved oxygen content (DO) of 8 to 9 ppm is considered -

Options

A. Moderately polluted
B. Slightly polluted
C. Good
D. Gravely polluted

Answer

To determine the classification of water with a dissolved oxygen content (DO) of 8 to 9 ppm, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Importance of Dissolved Oxygen (DO):**
- Dissolved oxygen is crucial for aquatic life. It indicates the water's ability to support fish and other organisms.

2. **Identify the Thresholds for Dissolved Oxygen Levels:**
- Water with a DO level below 5 ppm is generally considered polluted.
- A DO level between 5 to 6 ppm is considered slightly polluted.
- A DO level of 6 to 8 ppm is considered moderately polluted.
- A DO level above 8 ppm is considered good or suitable for aquatic life.

3. **Analyze the Given DO Level:**
- The question states that the water has a DO level of 8 to 9 ppm.

4. **Classify the Water Based on the DO Level:**
- Since the DO level of 8 to 9 ppm is above 8 ppm, it indicates that the water is suitable and healthy for aquatic organisms.

5. **Conclusion:**
- Therefore, water with a dissolved oxygen content of 8 to 9 ppm is classified as "good water."

### Final Answer:
Water with a dissolved oxygen content (DO) of 8 to 9 ppm is considered **good water**.

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