BOD

BIOCHEMICAL OXYGEN DEMAND

Biochemical oxygen demand (BOD) is the amount of dissolved oxygen needed by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period.

The BOD value is most commonly expressed in milligrams of oxygen consumed per litre of sample during 5 days of incubation at 20 °C and is often used to indicate of the degree of organic pollution of water.

BOD indicates the amount of organic pollution in a water body. It can also be used as a yard-stick to measure the effectiveness of wastewater treatment plants.

The ultimate BOD allows for an accurate calculation. where t is time, yt is the BOD in mg/L at time t, L is the original concentration of biodegradable organic matter, and k is the rate constant

Normally, the ultimate BOD is calculated for a time of 20 days.

e = 2.71828