What would happen if oxygen availability to activated sludge flocs is reduced? 1) It will slow down the rate of degradation of organic matter 2) The center of flocs will becomes anoxic, which would cause death of bacteria and eventually breakage of flocs 3) Flocs would increase in size as anerobic bacteria would grow around flocs 4) Protozoa would grow in large numbers

Options

A. It will slow down the rate of degradation of organic matter
B. The center of flocs will becoms anoxic, which would cause death of bacteria and eventually breakage of flocs
C. Flocs would increase in size as anerobic bacteria would grow around flocs
D. Protozoa would grow in large numbers

Explanation

To answer the question about the effects of reduced oxygen availability to activated sludge flocs, we can analyze the options step by step:

### Step-by-Step Solution:

1. **Understanding Activated Sludge and Flocs**:
- Activated sludge is a mixture of microorganisms, primarily bacteria, that are used in wastewater treatment to break down organic matter.
- Flocs are aggregates of these microorganisms that form a mesh-like structure, facilitating the treatment process.

2. **Role of Oxygen in Degradation**:
- Oxygen is crucial for the aerobic degradation of organic matter by bacteria in the activated sludge. It helps in the metabolic processes that convert organic waste into simpler substances.

3. **Impact of Reduced Oxygen**:
- When oxygen availability is reduced, the aerobic bacteria in the flocs cannot effectively degrade organic matter. This leads to a slowdown in the degradation process.

4. **Analyzing the Options**:
- **Option 1**: "It will slow down the rate of degradation of organic matter."
- This is true because less oxygen means that aerobic bacteria cannot function efficiently.
- **Option 2**: "The center of flocs will become anoxic, which would cause death of bacteria and eventually breakage of flocs."
- This could also happen as the center of the flocs might not receive enough oxygen, leading to anoxic conditions.
- **Option 3**: "Flocs would increase in size as anaerobic bacteria would grow around flocs."
- While anaerobic bacteria may grow, the overall health of the flocs would deteriorate due to the death of aerobic bacteria.
- **Option 4**: "Protozoa would grow in large numbers."
- This is less likely since protozoa depend on the health of bacteria, which would decline under low oxygen conditions.

5. **Conclusion**:
- The most direct and immediate consequence of reduced oxygen availability is that it will slow down the rate of degradation of organic matter, making **Option 1** the best answer.

### Final Answer:
The correct answer is **Option 1: It will slow down the rate of degradation of organic matter.**