is this statement True/false ?
Treatment of waste water is done by the Heterotrophic microbes naturally present in the sewage

Answer

To determine whether the statement "Treatment of wastewater is done by the Heterotrophic microbes naturally present in the sewage" is true or false, we can analyze the process of wastewater treatment.

### Step-by-Step Solution:

1. **Understanding Wastewater Treatment**: Wastewater treatment involves several processes to remove contaminants from sewage before it is released back into the environment.

2. **Primary Treatment**: The first step in wastewater treatment is primary treatment, which is primarily a physical process. This step involves filtration to remove larger particles and sedimentation to settle out heavier particles like sand and grit.

3. **Secondary Treatment**: After primary treatment, the wastewater moves to the secondary treatment stage. This is where biological treatment occurs, which is crucial for breaking down organic matter.

4. **Role of Heterotrophic Microbes**: In the secondary treatment, heterotrophic microbes, including bacteria and fungi, play a significant role. These organisms consume organic matter present in the sewage, effectively breaking it down.

5. **Formation of Flocs**: The action of these microbes leads to the formation of flocs, which are aggregates of microorganisms that help in further purifying the water.

6. **Biological Oxygen Demand (BOD)**: The activity of these heterotrophic microbes reduces the Biological Oxygen Demand (BOD) of the water, indicating a decrease in pollution levels and making the water clearer.

7. **Conclusion**: Since the treatment of wastewater indeed involves heterotrophic microbes that are naturally present in sewage, the statement is true.

### Final Answer:
The statement "Treatment of wastewater is done by the Heterotrophic microbes naturally present in the sewage" is **True**.

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