Biological oxygen is not a term commonly used; however, based on the provided information regarding "Biological Oxygen Demand (BOD)," we can infer the question likely refers to the oxygen required by biological organisms. More specifically, it refers to the amount of dissolved oxygen needed by aerobic organisms in water to break down organic matter. This is measured by what is known as Biological Oxygen Demand, or BOD.
Understanding Biological Oxygen Demand (BOD)
What is BOD?
BOD, or Biological Oxygen Demand, is a measure of the amount of dissolved oxygen needed by aerobic biological organisms to break down organic material present in a water sample. The breakdown process is biological, and these processes consume oxygen. A higher BOD indicates more organic material and therefore a greater amount of oxygen is required by microbes to decompose it.
Here's a more detailed breakdown:
- Aerobic Organisms: These are microorganisms that require oxygen for their metabolic processes. They are the primary agents in the breakdown of organic matter in aquatic environments.
- Organic Material: This includes pollutants such as sewage, decaying plant matter, and animal waste. These contain carbon compounds that microbes use as food.
- Dissolved Oxygen (DO): Oxygen gas dissolved in water. The amount of dissolved oxygen available is crucial for aquatic life.
- Breakdown Process: Aerobic microorganisms consume the organic matter and use oxygen in the process, similar to how humans use oxygen to burn fuel in their bodies.
How is BOD measured?
BOD is measured by incubating a water sample at a set temperature (usually 20°C) for a specific time period (usually 5 days). The difference between the initial and final dissolved oxygen concentration represents the BOD of the sample.
| Measurement | Description |
|---|---|
| Initial DO | Dissolved oxygen level at the start of incubation |
| Final DO | Dissolved oxygen level after a 5 day incubation |
| BOD = Initial DO - Final DO | BOD is determined by this calculation |
Why is BOD important?
BOD is a critical indicator of water quality. High BOD levels mean:
- Increased organic pollutants: More organic matter needs to be broken down, which uses more oxygen.
- Decreased DO: The oxygen that aquatic life needs is being used up in decomposition, potentially leading to oxygen depletion.
- Harm to aquatic life: Low DO levels can harm or kill fish and other aquatic organisms.
- Eutrophication: This is the enrichment of a water body with nutrients, leading to algal blooms, and subsequently, oxygen depletion.
Practical Implications
Monitoring BOD helps in:
- Wastewater treatment: To assess how effective sewage treatment plants are.
- Pollution control: To identify and regulate sources of organic pollution in natural waters.
- Environmental assessments: To evaluate the impact of human activity on aquatic ecosystems.
In Summary
While not a term used in environmental science, "biological oxygen" based on the given context of "biological oxygen demand (BOD)" can be understood as the oxygen needed by microorganisms for the breakdown of organic matter. High levels of demand means more organic pollution, which can harm aquatic life.
