Which of the following is / are proper method to dispose sludge ?
A) Incineration
B) Dumping
C) Anaerobic digestion by microbes
D) Filtration

Options

A. C,D
B. A,B
C. B,C,D
D. A,B,C,D

Answer

To determine the proper methods for disposing of sludge, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Sludge**:
- Sludge is a semi-solid by-product generated during the treatment of industrial or municipal wastewater. Proper disposal methods are essential for environmental safety.

2. **Option A: Incineration**:
- Incineration involves burning organic substances in the presence of oxygen. This method converts sludge into ash, flue gas, and heat. It is widely used for sludge disposal as it effectively reduces the volume and potential hazards of the waste.
- **Conclusion**: Incineration is a proper method for disposing of sludge.

3. **Option B: Dumping**:
- Dumping refers to the practice of discharging sludge waste into landfills or other areas. While it is a common practice, it may not be environmentally safe as it can lead to soil and water contamination.
- **Conclusion**: Dumping is not considered a proper method for disposing of sludge due to potential environmental risks.

4. **Option C: Anaerobic Digestion by Microbes**:
- Anaerobic digestion is a biological process where microorganisms break down organic matter in the absence of oxygen. This process converts sludge into biogas (methane) and digestate. It is an efficient and environmentally friendly method for sludge disposal.
- **Conclusion**: Anaerobic digestion is a proper method for disposing of sludge.

5. **Option D: Filtration**:
- Filtration is a process that separates solid particles from liquids. While it is essential for treating wastewater, it does not dispose of sludge but rather helps in the treatment process to reclaim water from sludge.
- **Conclusion**: Filtration is not a disposal method for sludge.

### Final Answer:
The proper methods to dispose of sludge from the given options are:
- A) Incineration
- C) Anaerobic digestion by microbes