The bod electrode method is suitable for determining the bod of water and wastewater. The bod 5 cod and the bod 5 cod sol indices are both consistent and can be both used as stability indices. What is the relationship between the cod and bod values in. Understanding biochemical oxygen demand bod introduction bod, like cod, is not one definable particle. Jul 20, 2016 cod or chemical oxygen demand is the total measurement of all chemicals in the water that can be oxidized.
Mihelcic encyclopedia of life support systems eolss 2. Organic matter nonbiodegradable and biodegradable toc, cod, do, bod, bodu and serial bod dr. The bod5 value of 1747 mg l 1, cod a value of 3595 m l 1 and journal of applied biotechnology issn 23270640 2020 bod cod ratio of 0. Cod is useful in terms of water quality by providing a metric to determine the effect an effluent will have on the receiving body, much like biochemical oxygen demand bod. Bod and cod in hindi biochemical oxygen demand and chemical oxygen demand duration. The key difference between bod and cod is that the bod is the oxygen demand of microorganisms to oxidize organic matter in the water under aerobic conditions while the cod is the oxygen demand to oxidize all the pollutants in the water chemically quality of a given water sample depends on some variable factors. Reddy thapar university patiala punjab 147 004 india 2. In environmental chemistry, the chemical oxygen demand cod is an indicative measure of the amount of oxygen that can be consumed by reactions in a measured solution. Estimation of biological oxygen demand and chemical. Standardization of bod 5 cod ratio as a biological stability. What is the relationship between the cod and bod values in waste. Cod often is used as a measurement of pollutants in wastewater and natural waters. Chemical oxygen demand cod vs biological oxygen demand bod. Classical definition very low concentration of dissolved molecular oxygen i.
The holding time for a bod sample is 48 hours from collection. However, another substance in wastewater leads to inhibition of bacteria that. Also, it can be categorized in several ways such as biological, physical and. Toc or total organic carbon is the measurement of organic carbons. A whole variety of organic matter can be present in water, which cannot be defined individually with considerable analytical effort and in short time. None of the alternatives provide a better assessment of the bioavailability of a waste like the bod test. D biochemical oxygen demand bod is 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. The standard method for indirect measurement of the amount of pollution that cannot be oxidized biologically in a sample of water. Oct 14, 2011 the key difference between bod and cod is that the bod is the oxygen demand of microorganisms to oxidize organic matter in the water under aerobic conditions while the cod is the oxygen demand to oxidize all the pollutants in the water chemically. Other related analytical values are biochemical oxygen demand bod, total organic carbon toc, and total oxygen demand tod. Chemical oxygen demand an overview sciencedirect topics. Biochemical oxygen demand or bod, is the amount of oxygen needed by organisms to break down the organic material in wastewater.
Bod5 is a measure of how much dissolved oxygen is consumed by aerobic bacteria in 5 days at 20oc. Organics 2 university of georgia cooperative extension circular 922. While the bod test is performed by using a population of bacteria and other microorganisms to attempt to duplicate what would happen in a. While the bod test is performed by using a population of bacteria and other microorganisms to attempt to duplicate what would happen in a natural stream over a period of five days, the. May 10, 2020 the organic strength of wastewater is measured in three ways. Chapter 3 selection of water quality variables world health. Bod is the amount of oxygen consumed by decomposition of the sample during the incubation period. Also, it can be categorized in several ways such as biological. The typical range of bod 5 in domestic wastewater ranges from 100 to 300 mgl.
The bod determination is an empirical test in which standardised laboratory procedures are. Bod, bod kinetics and cod tests are discussed at length. Bod primer page 4 of 61 biological background of all bodn determinations the primary difference between bodn determination and other measurements such as ph, conductivity, oxygen, cod, nitrate, etc. Biochemical oxygen demand bod and chemical oxygen demand pdf. A full explanation of any of the parameters can be found by clicking on the blue links. Chemical oxygen demand cod is a second method of estimating how much oxygen would be depleted from a body of receiving water as a result of bacterial action. The determination of chemical oxygen demand in waters and. Bod dan cod sebagai parameter pencemaran air dan baku mutu air limbah oleh. Bod, cod, toc and tod sum parameters in environmental. Biochemical oxygen demand definition of biochemical oxygen. Dec 16, 2015 deals with the measurement of organic matter concentration in water and wastewater.
A defined microbial consortium can be formed by conducting a systematic study, i. Bod, cod, toc and tod sum parameters in environmental analysis. Information and translations of cod in the most comprehensive dictionary definitions resource on the web. The bod value is most commonly expressed in milligrams of oxygen consumed per litre of sample during 5 days. Bod 5 cod and bod 5 cod sol are both consistent and significant as stability indices. Wastewater treatment modeling acknowledgments glossary bibliography biographical sketches.
The bod value is calculated from the depletion and the amount of sample used. Aug 04, 2017 have covered the theory of biochemical oxygen demand including the carbonaceous and nitrogenous demand, dilution method to calculate the bod the formulation of bod equation. Difference between bod and cod definition, test method and procedure, purpose 19. Bod biochemical oxygen demand is supposed to measure the amount of food or organic carbons that bacteria can oxidize. Determination of biological oxygen demand bod in waste. Biochemical oxygen demand chemical oxygen demand indicator organisms fecal coliform.
Measurement of organic matter concentration organic matter in wastewater is heterogeneous suspended colloidal and dissolved organic matter. Biochemical oxygen demand bod, the amount of dissolved oxygen used by microorganisms in the biological process of metabolizing organic matter in water. Where there is water and wastewater exist the cod and bod, and is in a ratio with the variation mentioned above. In cases where abuse is obvious, we have some authority, since the bod and total suspended solids test methods instruct analysts to select sample sizes to meet the stated minimum. Biochemical oxygen demand bod is a way to measure organic pollution in water by looking at the rate at which microorganisms in the water use up dissolved oxygen when they metabolize the organic pollutants. Cod is the amount of oxygen required for the oxidation of total organic matter in water. The bod 5 cod and the bod 5 cod sol ratio, as highlighted earlier, are in line with the indices on solid phase, except in the case of results from static leaching test of 6h duration, in particular for waste a and b. Further, as part of the ultimate bod measurement, other associated tests like dissolved oxygen and ammonical, nitrate and nitrite forms of nitrogen are also discussed. Chemical oxygen demand cod and biological oxygen demand bod are the two main characteristic properties that.
Bod in wastewater is the result of human waste, food waste and other organics which are sent to the sewers. Biochemical oxygen demand bod is defined as the amount of oxygen required by. The most popular sum parameter in waste water ana more. Quality of a given water sample depends on some variable factors. Bod biochemical oxygen demand is supposed to measure the amount of food. For the contaminants that can be oxidized biologically, the biological oxygen demand bod method is used.
Cod is a defined test, in other words, the extent of sample oxidation can be. Bod analysis is similar in function to chemical oxygen demand cod analysis, in that. Difference between bod and cod compare the difference. Cod is a measure of total organic molecules dissolved in waste water, where as the concept of bod came after cities started dumping their waste water into the water bodies and this led to. Looking for online definition of bod or what bod stands for. Wastewater treatment and discharge 2006 ipcc guidelines for national greenhouse gas inventories 6.
Biochemical oxygen demand environmental protection agency. The determination of chemical oxygen demand in waters and effluents 2007 methods for the examination of waters and associated materials this booklet contains guidance on methods for the determination of chemical oxygen demand using potassium dichromate solution, and notes for the disposal and recovery of selected reagents. Standardization of bod 5 cod ratio as a biological. What you should know the actual procedure is so much more involved than the summary given above. Cod is estimated to be a more useful parameter than bod, but from a modeling standpoint, cod cannot differentiate between biodegradable and inert organic. The biggest challenge in the bod test is that of time. The bod electrode method is suitable for determining the bod of water and.
Biochemical oxygen demand bod and chemical oxygen demand pdf 1. Unesco eolss sample chapters environmental and ecological chemistry vol. Most applications of cod determine the amount of organic pollutants found in surface water e. Biochemical oxygen demand bod waste water engineering. There are 4 common tests to determine organic pollution in wastewater. Determination of the biochemical oxygen demand bod in polluted waste water as a pollution indicator by incubating the bod bottles for five days at 20 degree c the amount of oxygen, taken up by the microorganisms that decompose the organic waste matter in wastewater is known as biological oxygen demand or biochemical oxygen demand. Cod or chemical oxygen demand is the total measurement of all chemicals in the water that can be oxidized.
Jun 07, 2017 difference between bod and cod definition. Difference between bod and cod definition, test method. D biochemical oxygen demand bod is 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. Highlights bod 5 cod on eluate of leaching test to assess the biological stability of waste. Ultimate bod ubod the ultimate biochemical oxygen demand ubod is a parameter that quantifies the. Cod is closely related to bod or biochemical oxygen demand, the difference being that bod is a test of the level of organic matter that can be biologically oxidised while cod is a test of the amount of organic matter that can be chemically oxidised. The ph is a measure of the acid balance of a solution and is defined as the.
Organics in wastewater may be refractory organics in wastewater are degradable. Bod is defined as the amount of oxygen demanded by the microorganisms in the sewage for the. The chemical oxygen demand cod test is commonly used to indirectly measure the amount of organic compounds in water. Waste is considered to be easily treatable by biological means if bodcod ratio is 0. Bod, chemical oxygen demand cod, total organic carbon. Recommendations of the bod lod technical group 071200 4 the department is somewhat concerned about permittees abusing the ability to report lessthan values. The relationship of bod and cod of river water for three rivers in malaysia are investigated over a period of one year.
High bodcod is indirect indicator of the organic content ammonia is inorganic and creates an oxygen. Correlation between biochemical oxygen demand and chemical. The most common application of cod is in quantifying the amount of oxidizable pollutants found in surface water e. Difference between bod and cod definition, test method and. For example, the organics in a wastewater sample represented by bod will also be. Have covered the theory of biochemical oxygen demand including the carbonaceous and nitrogenous demand, dilution method to calculate the bod the formulation of bod equation. Principal wastewater constituents treatment methods for. A cod test can be used to easily quantify the amount of organics in water. Bod is the amount of oxygen consumed by bacteria while decomposing organic matter under aerobic conditions. Typically, municipal wastewater treatment plants will use bod5 as a measure of the organic concentration into, and through, the wastewater plant. Biochemical oxygen demand bod is the amount of dissolved oxygen needed i.
Bod is listed in the worlds largest and most authoritative dictionary database of abbreviations and acronyms the free dictionary. Chemical oxygen demand cod vs biological oxygen demand. The standard method for indirect measurement of the amount of pollution that cannot be oxidized biologically in a sample. Appropriate protective equipment should be worn when undertaking the bod biochemical oxygen demand electrode method. Biochemical oxygen demand definition is the oxygen used in meeting the metabolic needs of aerobic microorganisms in water rich in organic matter such as water polluted with sewage. Atau sebaliknya, pada kasus pencemaran lainnya yang. The organic strength of wastewater is measured in three ways. Cod definition and meaning collins english dictionary.
Chemical oxygen demand cod vs biological oxygen demand bod bod measures the amount of oxygen required by the aerobic organisms to decompose organic matter and cod measures the oxygen required to decompose organic and inorganic constituents present in the wastewater by chemical reaction. It is the broad measure of the strength of the organic matter in a waste stream. Biochemical oxygen demand definition of biochemical. Wastewater basics 101 target audience policy makers, leaders, and planners people who have a water quality agenda this presentation discusses the fundamentals. High bod cod is indirect indicator of the organic content ammonia is inorganic and creates an oxygen. The bod5 value of 1747 mg l 1, cod a value of 3595 m l 1 and journal of applied biotechnology issn 23270640 2020 bodcod ratio of 0.
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