In clean water the concentration of

Options

A. BOD is low but DO is high
B. Both BOD and DO are high
C. BOD is high but DO is low
D. Both BOD and DO are low

Answer

**Step-by-Step Solution:**

1. **Understanding BOD and DO:**
- BOD stands for Biochemical Oxygen Demand, which measures the amount of oxygen required by microorganisms to decompose organic matter in water.
- DO stands for Dissolved Oxygen, which is the amount of oxygen available in water for aquatic organisms.

2. **Analyzing Clean Water:**
- Clean water is characterized by a low concentration of organic matter. This means that there are fewer nutrients available for microorganisms to decompose.
- Since there is little to no organic matter in clean water, the BOD will be low.

3. **Relationship Between BOD and DO:**
- BOD and DO are inversely related. This means that if BOD is high (indicating a lot of organic matter), DO will be low because the microorganisms consume oxygen to decompose the organic matter.
- Conversely, if BOD is low (as in clean water), DO will be high, providing sufficient oxygen for aquatic life.

4. **Evaluating the Options:**
- The question provides several options regarding the concentrations of BOD and DO in clean water:
- Option 1: BOD is low and DO is high.
- Option 2: Both BOD and DO are high.
- Option 3: BOD is high and DO is low.
- Option 4: Both BOD and DO are low.
- Given that clean water has low BOD and high DO, the correct option is **Option 1: BOD is low and DO is high.**

5. **Conclusion:**
- Therefore, in clean water, the concentration of BOD is low, and the concentration of DO is high.

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