A. Industrial pollution
B. Air pollution
C. Polluting capacity of effluent
D. Dissolved O2 needed by microbes to decompose organic waste
Correct Answer: D. Dissolved O2 needed by microbes to decompose organic waste
Detail about MCQs
Biochemical oxygen demand (BOD) refers to the amount of dissolved oxygen (DO) required by aerobic microorganisms to decompose organic matter in water at a specific temperature over a specific period of time. It’s a measure of the level of organic pollution in water bodies. As microorganisms break down organic material, they consume oxygen, so high BOD levels indicate high levels of organic pollution, which can deplete oxygen levels in aquatic ecosystems and harm aquatic life.