The test for biochemical oxygen demand (bod) is a bioassay procedure that measures the oxygen consumed by bacteria from the decomposition of organic matter (sawyer and mccarty, 1978). The change in do concentration is measured over a given period of time in water samples at a specified temperature.
How Is Biochemical Oxygen Demand Measured?
Biochemical Oxygen Demand (BOD) is a key indicator of water quality, used to measure the amount of oxygen needed to support biological activity in a body of water such as a lake or river. It is a measure of the amount of organic matter present in the water, which leads to the decrease in available oxygen levels. High BOD levels can be detrimental to aquatic life and can lead to an increase in algae growth, reduced dissolved oxygen levels, and an increase in water temperature.
The most commonly used method for measuring BOD is through the use of a biochemical oxygen demand test. This test measures the amount of dissolved oxygen consumed by micro-organisms when decomposing organic matter. The test is usually conducted over a period of five days, with samples taken from the water at different intervals.
The sample is placed in a sealed container and is incubated at 20°C in the dark. At the end of the five day period, the sample is tested to measure the amount of oxygen consumed by the micro-organisms. The difference between the amount of oxygen present in the sample when it was sealed and the amount present after the five day period is the BOD.
The BOD is an important measure of water quality in lakes, rivers
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