# Biochemical Oxygen Demand (BOD) is the amount of oxygen required (in ppm):

Question:

Biochemical Oxygen Demand (BOD) is the amount of oxygen required (in ppm):

1. by anaerobic bacteria to breakdown inorganic waste present in a water body.

2. for the photochemical breakdown of waste present in $1 \mathrm{~m}^{3}$ volume of a water body.

3. by bacteria to break-down organic waste in a certain volume of a water sample.

4. for sustaining life in a water body.

Correct Option: , 3

Solution:

Biochemical oxygen demand (BOD) is amount of oxygen required by bacteria to break down organic waste in a certain volume of water sample.