Clean water with BOD value and pH range when it is recommended as a drinking water respectively should be

Options

A. Less than 5 pm and 5.5 to 9.5
B. More than 5ppm and 5.5 to 9.5
C. More than 10 ppm and 3 to 4
D. More than 15 ppm and 8 to 10

Answer

To determine the clean water standards regarding BOD (Biochemical Oxygen Demand) and pH for drinking water, we can break down the solution into a few clear steps:

### Step 1: Understand BOD
- **Definition**: BOD stands for Biochemical Oxygen Demand. It measures the amount of oxygen that microorganisms will consume while decomposing organic matter in water.
- **Clean Water Standard**: For clean water, the BOD value should be **less than 5 ppm** (parts per million). This indicates that the water has low levels of organic pollution and is suitable for drinking.

### Step 2: Understand pH
- **Definition**: pH is a measure of the acidity or basicity of a solution. It is defined as the negative logarithm of the hydrogen ion concentration.
- **pH Scale**:
- pH < 7: Acidic
- pH = 7: Neutral
- pH > 7: Basic
- **Recommended pH Range for Drinking Water**: The safe pH range for drinking water is typically between **6.5 to 8.5**. This means that water within this range is neither too acidic nor too basic, making it safe for consumption.

### Step 3: Combine the Standards
- Based on the definitions and standards established:
- **BOD Value**: Less than 5 ppm
- **pH Range**: 6.5 to 8.5 (or more broadly, 5.5 to 9.5 is acceptable for some sources)

### Conclusion
Therefore, the clean water with BOD value and pH range recommended for drinking water should be:
- **BOD**: Less than 5 ppm
- **pH**: 5.5 to 9.5

### Final Answer
The correct option is: **Less than 5 ppm for BOD and 5.5 to 9.5 for pH.**

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