What BOD means?

What BOD means?

BOD indicates the amount of putrescible organic matter present in water. Therefore, a low BOD is an indicator of good quality water, while a high BOD indicates polluted water. Dissolved oxygen (DO) is consumed by bacteria when large amounts of organic matter from sewage or other discharges are present in the water.

What is BOD and COD?

The biochemical oxygen demand (BOD) represents the amount of dissolved oxygen (DO) consumed by biological organisms when they decompose organic matter in water. The chemical oxygen demand (COD) is the amount of oxygen consumed when the water sample is chemically oxidised.

How is BOD measured?

BOD measurement requires taking two samples at each site. One is tested immediately for dissolved oxygen, and the second is incubated in the dark at 20 C for 5 days and then tested for the amount of dissolved oxygen remaining.

Why BOD is important?

The BOD is an important parameter for assessing water quality. It deals with the amount of oxygen consumption (mg O2 L− 1) by aerobic biological organisms to oxidize organic compounds. Sewage with high BOD can cause a decrease in oxygen of receiving waters, which in turn can cause the death of some organism.

Is high BOD good?

Higher BOD indicates more oxygen is required, which is less for oxygen-demanding species to feed on, and signifies lower water quality. Inversely, low BOD means less oxygen is being removed from water, so water is generally purer.

How is BOD removed from wastewater?

BOD is fairly easy to remove from sewage by providing a supply of oxygen during the treatment process; the oxygen supports bacterial growth which breaks down the organic BOD. Most enhanced treatment units described incorporate some type of unit which actively oxygenates the sewage to reduce BOD.

What is COD civil?

COD: COD is the amount of oxygen required for the oxidation of total organic matter in water.

Is COD greater than BOD?

It is a test of the amount of oxygen required to oxidise organic matter in a sewage sample by chemical oxidation with a powerful oxidising agent such Potassium Dichromate. ... COD is normally higher than BOD because more organic compounds can be chemically oxidised than biologically oxidised.

Why is COD higher than BOD?

COD is normally higher than BOD because more organic compounds can be chemically oxidised than biologically oxidised. This includes chemicals toxic to biological life, which can make COD tests very useful when testing industrial sewage as they will not be captured by BOD testing.

What is BOD 5days?

Method Description: The five day BOD is an indicator of how much oxygen is utilized by a natural water sample (phytoplankton and bacteria) in five days at 20 degrees C.

What does BOD stand for?

• What Is Biological Oxygen Demand in Wastewater Treatment? Biochemical oxygen demand or biological oxygen demand (BOD) is a measure of the amount of Dissolved Oxygen (DO) required by aerobic microorganisms to decompose organic matter present in a sample of water at a certain temperature over a studied period.

What is bod in wastewater?

• BOD can be used as a gauge of the effectiveness of wastewater treatment plants. It is listed as a conventional pollutant in the U.S. Clean Water Act. BOD is similar in function to chemical oxygen demand ( COD ), in that both measure the amount of organic compounds in water.

What is the BOD POD?

• BOD POD: A method for determining the lean body mass. The BOD POD is a computerized, egg-shaped chamber. Using the same whole-body measurement principle as underwater weighing, the BOD POD measures a subject's mass and volume, from which their whole-body density is determined.