Significance of BOD
- BOD finds its primary importance in sewage treatment plants. ...
- It determines the rate of respiration in living beings.
- Measuring BOD gives the COD or Chemical Oxygen Demand of inorganic substances.
- It indicates the polluting potential of water.
- BOD is used in medical and pharmaceutical industries to measure the oxygen consumption of cell cultures.
What is bod in wastewater and why is it important?
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.
What are the sources of BOD in sewage treatment?
The “Demand” part of BOD can have several different sources - natural materials like leaves and animal manure or man-made pollutants like waste from industrial activity are just a few examples of places anaerobic bacteria are borne from in our sewer collection systems.
What is a BOD test and why is it important?
Municipalities can use a BOD test to detect water contamination in their public supply to ensure that it is safe for human consumption. Industries need to know their BOD value to determine when treated wastewater is safe for reuse or disposal. Several techniques are used for BOD removal in wastewater prior to reuse or safe disposal.
What are the BOD reduction methods for wastewater treatment?
Three common BOD reduction methods for wastewater treatment are: Wastewater clarification and separation BOD reduction methods are part of the primary phase of wastewater treatment while anaerobic microbial decomposition is part of the second phase of treatment.
Why is BOD important in wastewater treatment?
Biochemical oxygen demand / biological oxygen demand is an important water quality parameter because it provides an index to assess the effect discharged wastewater will have on the receiving environment.
Why is BOD5 important?
The BOD5 indicates how much dissolved oxygen (mg / l) is needed in a given time for the biological degradation of the organic wastewater constituents. This value is an important parameter for the assessment of the degree of pollution that wastewater represents for the environment (receiving water).
How is biochemical oxygen demand related to sewage?
Wastewater from sewage treatment plants often contains organic materials that are decomposed by microorganisms, which use oxygen in the process. (The amount of oxygen consumed by these organisms in breaking down the waste is known as the biochemical oxygen demand or BOD.
What is the purpose of BOD?
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).
What are the advantages of BOD?
The main advantages of this method compared to the dilution method are: simplicity: no dilution of sample required, no seeding, no blank sample. direct reading of BOD value. continuous display of BOD value at the current incubation time.
What is the significance of BOD and COD of water sample?
Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) are two of the most important parameters to characterise (measure the degree of pollution) of wastewater. BOD, the biological demand for oxygen a source of water has, is the amount of oxygen used by microorganisms to break down organic substances.
What is the relationship between BOD and organic matter in sewage?
What is relationship between BOD and organic matter in sewage ? BOD is directly proportional to the amount of organic matter in sewage that is if the BOD is high the amount of organic matter is also high whereas Low BOD denotes less organic matter.
What happens if BOD is low?
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 is BOD reduced in secondary sewage treatment?
During the secondary treatment of primary effluents, the BOD level decreases because useful microbes consume a major part of the organic matter. Reduction in the organic matter leads to lowering of BOD.
Why is BOD high in polluted water?
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.
How does BOD measure water quality?
The BOD value is then calculated from the depletion and the size of the sample used. The DO readings are usually in parts per million (ppm). Higher BOD indicates more oxygen is required, signifying lower water quality. Low BOD means less oxygen is being removed from water, so the water is usually more pure.
What is BOD and COD in sewage treatment plant?
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.
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.
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).
What is the function of BOD in water?
BOD also measures the chemical oxidation of inorganic matter (i.e., the extraction of oxygen from water via chemical reaction).
How does BOD affect oxygen consumption?
The rate of oxygen consumption in a stream is affected by a number of variables: temperature, pH, the presence of certain kinds of microorganisms, and the type of organic and inorganic material in the water. BOD directly affects the amount of dissolved oxygen in rivers and streams.
How does BOD affect oxygen?
Aeration of stream water by rapids and waterfalls, for example will accelerate the decomposition of organic and inorganic material. Therefore, BOD levels at a sampling site with slower, deeper waters might be higher for a given volume of organic and inorganic material than the levels for a similar site in highly aerated waters.
What is the oxygen demand in wastewater treatment plants?
Wastewater from sewage treatment plants often contains organic materials that are decomposed by microorganisms, which use oxygen in the process. (The amount of oxygen consumed by these organisms in breaking down the waste is known as the biochemical oxygen demand or BOD.
Why is dissolved oxygen important?
What is dissolved oxygen and why is it important? The stream system both produces and consumes oxygen. It gains oxygen from the atmosphere and from plants as a result of photosynthesis. Running water, because of its churning, dissolves more oxygen than still water, such as that in a reservoir behind a dam.
What is the source of oxygen waste?
Other sources of oxygen-consuming waste include stormwater runoff from farmland or urban streets, feedlots, and failing septic systems. Oxygen is measured in its dissolved form as dissolved oxygen (DO). If more oxygen is consumed than is produced, dissolved oxygen levels decline and some sensitive animals may move away, weaken, or die.
Where is the DO level in a dam?
The DO levels in and below riffle areas, waterfalls , or dam spillways are typically higher than those in pools and slower-moving stretches. If you wanted to measure the effect of a dam, it would be important to sample for DO behind the dam, immediately below the spillway, and upstream of the dam.
