Flocs' is

Options

A. Primary sludge produced in sewage treatment
B. A type of biofortified food
C. A mesh like structure formed by association of bacteria and fungal filaments in sewage treatment
D. The effluent in primary treatment tank obtained during sewage treatment

Answer

**Step-by-Step Solution:**

1. **Understanding the Term 'Flocs':**
- The term 'flocs' refers to a specific structure formed during the sewage treatment process.

2. **Sewage Treatment Process:**
- Sewage treatment involves two main stages: primary treatment and secondary treatment.
- **Primary Treatment:** This stage involves the physical removal of large solids and debris from sewage, such as plastics and wood. It acts as a filter to separate these materials.
- **Secondary Treatment:** This stage is biological and involves the use of microorganisms to break down organic matter in the sewage.

3. **Formation of Flocs:**
- During the secondary treatment, microorganisms, particularly bacteria and fungal filaments, aggregate to form a mass-like structure known as flocs.
- These flocs trap pollutants and help in their degradation, making the sewage treatment process more efficient.

4. **Identifying the Correct Definition:**
- Based on the explanation, flocs can be defined as a mass-like structure formed by the association of bacteria and fungal filaments during the sewage treatment process.

5. **Selecting the Correct Option:**
- Among the given options, the correct definition of flocs is: "a mass-like structure which is formed by the association of bacteria and fungal filament in sewage treatment." This corresponds to option three.

**Final Answer:**
- The correct answer is option C: "a mass-like structure which is formed by the association of bacteria and fungal filament in sewage treatment."

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