pH favourable for fermentation in biogas plant is

Options

A. `4-5`
B. `5-6`
C. `6.5-7.2`
D. `7.6-8.4`

Answer

To determine the pH favorable for fermentation in a biogas plant, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Biogas and Its Composition**:
- Biogas is a mixture of gases, primarily methane, hydrogen, carbon dioxide, and traces of sulfur compounds. It is produced through the anaerobic breakdown of organic matter.

2. **Identify the Raw Materials**:
- The primary raw material used in biogas plants is organic matter, commonly cow dung.

3. **Recognize the Role of Bacteria**:
- The fermentation process in biogas plants is facilitated by specific bacteria known as methanogens, which are a type of archaebacteria.

4. **Determine the Optimal pH Range for Methanogens**:
- Methanogens are most active and efficient in a specific pH range. Research indicates that the optimal pH for these bacteria is between 6.5 to 7.2.

5. **Evaluate the Given Options**:
- The options provided are:
- A) 4 to 5 (too acidic)
- B) 5 to 6 (still acidic)
- C) 6.5 to 7.2 (optimal range)
- D) 7.6 to 8.4 (slightly alkaline)
- From the analysis, options A, B, and D are not suitable as they fall outside the optimal pH range for methanogens.

6. **Conclude the Correct Answer**:
- Therefore, the correct answer is **C) 6.5 to 7.2**, as this is the pH range favorable for fermentation in a biogas plant.