Oxygen demand ?

Oxygen demand refers to the amount of oxygen required by microorganisms to break down organic matter in water. It is a measure of the level of pollution in water bodies, as higher levels of organic matter and pollutants result in higher oxygen demand. This can lead to oxygen depletion in water, which can harm aquatic life and disrupt the ecosystem. Monitoring and managing oxygen demand is important for maintaining water quality and protecting the environment.

Biochemical oxygen demand (BOD)

- Definition: The amount of oxygen required by aerobic microorganisms to decompose organic matter in water over a specific period of time (usually 5 days).
- Measurement: Measured in milligrams of oxygen per liter (mg/L) of water.
- Significance: Indicates the amount of organic pollution in water and the potential for oxygen depletion, which can harm aquatic life.

Chemical oxygen demand (COD)

- Definition: The amount of oxygen needed to completely oxidize all organic matter in water using a strong chemical oxidant (e.g., potassium permanganate).
- Measurement: Measured in mg/L of oxygen.
- Significance: Provides a more comprehensive measure of organic pollution than BOD.

Total oxygen demand (TOD)

- Definition: The sum of BOD and COD.
- Significance: Represents the total oxygen required to decompose all organic matter in water.