BOD of waste water is estimated by measuring the amount of

Options

A. Total organic matter
B. Biodegradable organic matter
C. Oxygen evolution
D. Oxygen consumption

Answer

To solve the question regarding how the BOD (Biochemical Oxygen Demand) of wastewater is estimated, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding BOD**:
- BOD stands for Biochemical Oxygen Demand. It is a measure of the amount of dissolved oxygen that aerobic biological organisms will consume while decomposing organic matter in water.

2. **Role of Aerobic Organisms**:
- Aerobic organisms require oxygen to break down organic materials present in wastewater. The more organic matter there is, the more oxygen these organisms will consume.

3. **Measurement of Dissolved Oxygen**:
- To estimate BOD, we measure the amount of dissolved oxygen in a water sample before and after a certain period (usually 5 days) of incubation at a specific temperature (usually 20°C).

4. **Calculating BOD**:
- The difference in the amount of dissolved oxygen before and after the incubation period indicates how much oxygen has been consumed by the aerobic organisms. This consumption is directly related to the amount of organic matter present in the sample.

5. **Conclusion**:
- Therefore, the BOD of wastewater is estimated by measuring the amount of **oxygen consumption** in the water sample.

### Final Answer:
The BOD of wastewater is estimated by measuring the amount of **oxygen consumption**.