What is Biological Oxygen Demand (BOD)?

Organic pollutant in water.

THe correct answer is option 1. Organic pollutant in water.

Biological Oxygen Demand (BOD) refers to Organic pollutant in water.

1. Definition:

BOD is a measure of the amount of dissolved oxygen consumed by microorganisms (bacteria and other aerobic organisms) in water while they decompose organic matter. It is commonly used as an indicator of the organic pollution level in water.

2. Organic Pollutants:

The organic matter present in water, such as sewage, industrial effluents, or decaying plant material, serves as a source of energy for microorganisms. As these microorganisms break down the organic compounds, they consume dissolved oxygen in the water.

3. Measurement:

BOD is usually expressed in milligrams of oxygen consumed per liter of water (mg/L). The BOD test is conducted by measuring the dissolved oxygen content in a water sample initially and after a specified incubation period (usually 5 days at 20 degrees Celsius). The difference in dissolved oxygen concentrations provides an indication of the BOD.

4. Significance:

High BOD levels in water indicate a higher load of organic pollutants, which can lead to a decrease in dissolved oxygen levels. Insufficient dissolved oxygen in water can adversely affect aquatic life, as many organisms, particularly fish, require oxygen to survive.

5. Environmental Impact:

The discharge of untreated or poorly treated wastewater into water bodies can elevate BOD levels, causing oxygen depletion and leading to adverse effects on aquatic ecosystems. It is essential to monitor and control BOD levels to protect water quality and aquatic life.

In summary, BOD is a crucial parameter used to assess the organic pollution level in water and its potential impact on the aquatic environment. It provides valuable information for water quality management and environmental protection.