Question

What is biological oxygen demand? Explain briefly.

Answer 1

Biochemical Oxygen Demand (BOD, also called Biological Oxygen Demand) is the amount of dissolved oxygen needed (i.e. demanded) by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period.

Answer 2

Biological oxygen demand is a measure a measure of the oxygen utilized by micro-organisms during oxidation of organic substances. Micro-organisms present in  polluted water sample use oxygen to oxidized waste, and thus BOD increases in polluted water. Decreases in the amount of oxygen is the BOD value. Biological oxygen demand increases in polluted water.