In the biological treatment for sewage , microbes are used for the reduction of the organic matter in the sewage water which are held together by fungal filament to form mesh like structures . These are called as :

Options

A. Activated sludge
B. Aerobic process
C. Flocs
D. Anaerobic sludge

Answer

To solve the question regarding the biological treatment of sewage and the mesh-like structures formed by microbes and fungal filaments, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Biological Treatment**:
- In sewage treatment, biological methods are employed to reduce organic matter. This process primarily involves the use of microbes.

2. **Role of Microbes**:
- Microbes, including bacteria and fungi, play a crucial role in breaking down organic matter present in sewage water.

3. **Formation of Mesh-like Structures**:
- During the biological treatment, these microbes aggregate and are held together by fungal filaments, which leads to the formation of a structure that resembles a mesh.

4. **Terminology**:
- The specific term used to describe these mesh-like structures formed by the aggregation of microbes and fungal filaments is "flocs."

5. **Conclusion**:
- Therefore, the answer to the question is that these mesh-like structures are called "flocs."

### Final Answer:
The mesh-like structures formed by microbes and fungal filaments in the biological treatment of sewage are called **flocs**.

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