BOD of drinking water is:

Options

A. more than dirty water
B. less than dirty water
C. equal to dirty water
D. all of these

Answer

**Step-by-Step Solution:**

1. **Understanding BOD**: Begin by defining Biological Oxygen Demand (BOD). BOD is a measure of the amount of oxygen that microorganisms will consume while decomposing organic matter in water. It indicates the level of pollution in water.

2. **BOD in Different Types of Water**: Recognize that BOD levels vary between clean and polluted water. In polluted water (like sewage), the concentration of organic matter is high, leading to a higher demand for oxygen by aerobic microorganisms.

3. **BOD in Drinking Water**: In contrast, drinking water is treated and purified, resulting in a significantly lower concentration of organic matter and, consequently, a lower BOD. The presence of aerobic microorganisms in drinking water is minimal, which is why it is considered safe for consumption.

4. **Comparison**: Compare the BOD levels of drinking water and dirty water. Since dirty water has a high concentration of organic materials and microorganisms, its BOD is high, while drinking water has a low BOD due to its purity.

5. **Conclusion**: Therefore, the BOD of drinking water is less than that of dirty water. This indicates that drinking water is much cleaner and safer for consumption.

**Final Answer**: The BOD of drinking water is less than that of dirty water.

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