What is BOD in environmental science?
Biochemical oxygen demand (BOD) represents the amount of oxygen consumed by bacteria and other microorganisms while they decompose organic matter under aerobic (oxygen is present) conditions at a specified temperature.
What is BOD and do in water?
Biochemical oxygen demand (BOD) is the amount of dissolved oxygen (DO) 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.
How is BOD related to water pollution?
So, the higher the amount of organic pollutants in the water, the higher oxygen is required by the bacteria and this oxygen required by the bacteria is known as BOD. So, the amount of pollution in a water body is directly proportional to the BOD. BOD depends on time and temperature.
Is BOD a pollutant?
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 COD in that both measure the amount of organic compounds in water.
What is the example of BOD?
Sources of BOD
Sources of biological oxygen demand include leaves and woody debris; dead plants and animals; animal manure; effluents from pulp and paper mills, wastewater treatment plants, feedlots, and food-processing plants; failing septic systems; and urban storm water runoff.
What is the BOD of seawater?
At the same time, this parameter is used to evaluate the efficiency with which certain processes remove biodegradable natural organic matter (NOM). However, the values of BOD in seawater are very low (around 2 mg O2 L−1) and the methods used for its analysis are poorly developed.
What is the purpose of BOD?
Biochemical oxygen demand, or BOD, is a chemical procedure for determining the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period.
What causes BOD?
Sources of BOD include leaves and woody debris; dead plants and animals; animal manure; effluents from pulp and paper mills, wastewater treatment plants, feedlots, and food-processing plants; failing septic systems; and urban stormwater runoff.
How is BOD harmful?
The greater the BOD, the more rapidly oxygen is depleted in the stream. This means less oxygen is available to higher forms of aquatic life. The consequences of high BOD are the same as those for low dissolved oxygen: aquatic organisms become stressed, suffocate, and die.
Why is BOD important in water quality?
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.
What is BOD and how it is determined?
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 BOD measured in water?
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.
What causes high BOD in water?
Sources: BOD represents the amount of organic matter in a water supply; therefore, it increases when decaying plants, human or animal waste, and other organic compounds are added to water.
What is the normal BOD in water?
Drinking water has a BOD level of 1 – 2 ppm. When the BOD value of water is in the range 3 – 5 ppm, the water is moderately clean. Polluted water has a BOD value in the range of 6 – 9 ppm.
What affects BOD?
The factors affecting BOD include the type and amount of organic material present, the temperature, the pH, the dissolved oxygen concentration, and the presence of bacteria.
What happen if BOD is high?
The dissolved oxygen readings are usually in parts per million (ppm). 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.
Why BOD is important?
What happens when BOD is high?
What is the BOD of normal water?
Drinking water has a BOD level of 1 – 2 ppm. When the BOD value of water is in the range 3 – 5 ppm, the water is moderately clean. Polluted water has a BOD value in the range of 6 – 9 ppm. In polluted water, some organic waste is present.