The rate at which wastewater requires oxygen is known as the biological oxygen demand (BOD). BOD is a crucial factor in refining wastewater. The bacteria are important for breaking down substances, however too much BOD can cause unwanted amounts of bacteria.
What is bod in wastewater treatment?
Wastewater is water that has been contaminated from human activity, environmental, or industrial processes and must be treated for reuse or safe disposal. Usually determined alongside chemical oxygen demand (COD) in wastewater treatment, BOD is an important index that every industrial and municipal authority in the country should be aware of.
What is BOD and why is it so important?
BOD is considered to be one of the most important measurements to be taken in wastewater treatment and is a key indicator of water health and safety. Think about it this way - oxygen and water already go hand in hand in terms of molecular makeup, and it is also used by the microorganisms that form in the water to break down any organic solids.
What is biological oxygen demand in wastewater treatment?
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.
Why is it important to remove solids and BOD in wastewater?
The importance of removing solids and BOD in wastewater is just as important to a small office park as it is to an entire city. Wastewater treatment utilizes several delicate chemical processes to achieve an acceptable quality of water, which is analogous to an acceptable quality of life.
What is BOD and why is it important for water treatment?
BOD has traditionally been used to measure of the strength of effluent released from conventional sewage treatment plants to surface waters or streams. This is because sewage high in BOD can deplete oxygen in receiving waters, causing fish kills and ecosystem changes.
What is BOD in wastewater treatment?
BOD is a measure of the amount of oxygen required to remove waste organic matter from water in the process of decomposition by aerobic bacteria (those bacteria that live only in an environment containing oxygen).
Why BOD reduction is important in wastewater treatment?
BOD is a crucial factor in refining wastewater. It can also drain receiving waters of oxygen which can kill fish and harm the environment. Therefore it is important to control the level of BOD at every stage of the treatment process, and to remove as much as possible in the final stages.
What is the importance of BOD value to water quality?
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.
What is BOD explain?
BOD is defined as the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down the organic material present in a water sample, at a specific temperature and specified period.
What causes high BOD in wastewater?
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 happens when BOD is high?
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.
What is BOD and TSS?
Summary. Biochemical oxygen demand (BOD) and total suspended solids (TSS) are related. A portion of the TSS, the volatile suspended solids, is degradable and exerts an oxygen demand in a facultative lagoon or BOD test. BOD is a measurement of the quantity of oxygen required by bacteria to degrade substrate.
How is high BOD wastewater treated?
These are the best practices for reducing BOD and TSS that facility managers should know:Focus on removing TSS from wastewater first. ... Get a properly sized EQ tank. ... Control the pH of the waste stream. ... Install a modern plate pack DAF made of stainless steel or plastic. ... Use a regenerative turbine air dissolution pump.More items...•
What is BOD value of water?
BOD values range widely; generally, pristine waters have a value below 1 mg l−1, moderately polluted waters 2–8 mg l−1, and treated municipal sewage 20 mg l−1. Standards for the discharge of effluent from WWTPs have the range 20–30 mg l−1 and require a minimum flow in receiving waters to ensure sufficient dilution.
Why BOD test is done?
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.
Is BOD good for water?
However, if the B.O.D. is low, there is an abundance of Oxygen which leads to good water quality. The B.O.D. is an important water quality factor that is directly related to the overall health of the water body.
1.What is BOD?
Biological oxygen demand (BOD) is the quantity of oxygen consumed by the aerobic bacteria used in the oxidation of organic matter.
What is COD?
Chemical Oxygen Demand is a measure of oxygen utilized to chemically oxidize the organic matter used to assess the effect of discharged wastewater...
What is the safest level of DO for aquatic life?
5 parts per million (ppm) is the ideal dissolved oxygen concentration for aquatic life.
What is a clarifier?
In the metal tank used in the process of sedimentation of waste from water.
What is WWTP?
Wastewater Treatment Plant is man made infrastructure involved in treating the wastewater.
Wastewater BOD And Pollution
BOD is considered to be one of the most important measurements to be taken in wastewater treatment and is a key indicator of water health and safety.
The Role BOD Plays In Water
Dissolved oxygen plays a big role in natural water sources. Without the right concentration of dissolved oxygen, aquatic life and water quality start to deteriorate.
BOD In Wastewater Treatment Plants
As mentioned, BOD is a key indicator of organic pollution in wastewater. This means that the industrial sector is tasked with discharging their final water product only if it meets the right level of BOD.
The In-Pipe Difference
Wastewater treatment is a careful biological process. The microorganisms already naturally present in the wastewater do the majority of the work when it comes to reducing harmful nutrients and push clean water back into the waterways.
In-Pipe And FOG
In-Pipe is also effective when it comes to dealing with FOG. Food-related industries are some of the most notorious sources of FOG in sewer collection systems, and the build-up can cause serious issues. These blockages require regular, labor-intensive cleaning which can be costly to do on a consistent basis.
Wastewater Treatment
In untreated wastewater, the availability of organic carbon is relatively abundant and has become a critical concern for operators of Water Resource Recovery Facilities (WRRF). The dissolved oxygen is used to consume organic carbon in treated wastewater.
Environmental Impact
Oxygen demand plays an important role in aquatic life. The aquatic ecosystem has a cycle which comprises taking up inorganic nutrients to produce organic tissue by algae and other producers in the water.
Conclusion
Thus it is very important to monitor the BOD and COD in wastewater in order to prevent environmental pollution and it becomes a life saving measure for aquatic animals and fishes. RLT provides BOD and COD analysers with advanced technology and is capable of providing accurate data in real time.
Why is BOD important?
BOD is a crucial factor in refining wastewater. The bacteria are important for breaking down substances, however too much BOD can cause unwanted amounts of bacteria. It can also drain receiving waters of oxygen which can kill fish and harm the environment.
Why is it important to remove solids from wastewater?
The importance of removing solids and BOD in wastewater is just as important to a small office park as it is to an entire city. Wastewater treatment utilizes several delicate chemical processes to achieve an acceptable quality of water, which is analogous to an acceptable quality of life. Wastewater contains many elements which break down ...
What is the most effective way to get inorganic solids out of a septic system?
Inorganic material and other TSS (Total Suspended Solids) are most effectively taken out of wastewater through the use of effluent filters .
What are the elements that make up waste water?
Wastewater contains many elements which break down into two groups, organic and inorganic substances.Organic substances include dish soaps, fecal matter, and food particles. These elements break down and feed bacteria which exist in the septic system. Bacteria naturally decomposes organic matter, but requires oxygen to do so.
Is a septic system aerobic or anaerobic?
Many septic systems have both an aerobic and anaerobic process, while others focus on reducing the need of BOD altogether.
Does bacteria decompose organic matter?
Bacteria naturally decomposes organic matter, but requires oxygen to do so. The larger and more numerous the organic matter, the more oxygen required to eliminate organic matter. The rate at which wastewater requires oxygen is known as the biological oxygen demand (BOD).
What is a BOD value?
BOD values are generally determined and evaluated in association with other parameters (e.g., COD, DOC, POC, TOC) and this makes them more useful in formulating predictions. For example, if we consider a comparison of the measured BOD value with the COD value:
What are the conditions for determining BOD?
The conditions for determining BOD are so defined that the quantity alone of the organic materials contained in a sample limits the growth of microorganisms - i.e., the greater the number of organic nutrients present, the greater the material-exchange activity of the bacteria and , therefore, the resultant BOD.
What is the BOD of oxygen?
BOD n (Biochemical Oxygen Demand after n days) is defined in detail in German Standard DIN 38 409-H51 1 and is associated with certain experimental conditions. It represents the quantity of oxygen which is consumed in the course of aerobic processes of decomposition of organic materials, caused by microorganisms. The BOD therefore provides information on the biologically-convertible proportion of the organic content of a sample of water. This leads to the consideration of these materials in terms of their susceptibility to oxidation by the use of oxygen. BOD is stated in mg/l of oxygen and is usually measured within a period of 5 days (BOD 5 ).
What does a high BOD mean?
In general, the following assertions may be made: • a high BOD indicates a high content of easily degradable, organic material in the sample. • a low BOD indicates a low volume of organic materials, substances which are difficult to break down or other measuring problems (see below)
How long is a BOD graph?
However, in some countries a testing period of 7 days is performed. A so-called BOD-Graph can be drawn up, in which BOD values are shown in graphical form over a given period of time. A slight deviation from the kinetic described above occurs, caused by fluctuations in the rate of breakdown.
How does biodegradation occur in water?
Biodegradation of materials present in water occurs in two phases. The breakdown of carbons begins practically immediately . In the second phase, nitrification occurs, which also involves the consumption of oxygen. There are two groups of nitrifying bacteria, which catalyse the synthesis in a close relationship.
When was the first Bod measured?
In this connection, BOD is employed to determine the aerobic destructibility of organic substances. As long ago as 1870, Frankland carried out the first BOD measurements, which were very similar to the dilution method in use today (see below).
