Biochemical oxygen demand bod bod is an empiric laboratory assay which measures the amount of organic matter contained in a water sample. Bod primer page 2 of 61 preface the determination of biochemical oxygen demand is always a topic of discussion with regard to the method and its applicability. Mihelcic encyclopedia of life support systems eolss summary biochemical oxygen demand bod is a measure of the dissolved oxygen consumed by microorganisms during the oxidation of reduced substances in waters and wastes. A consumers guide to bod 5 5day biochemical oxygen. Understanding dilution and seeding procedures in bod test target group.
Accurate bod measurements with electrochemical and. Add dilution water until the bottles are completely filled. General discussion the biochemical oxygen demand bod determination is an empirical test in which standardized laboratory procedures are used to determine the relative oxygen requirements of wastewaters, ef. Syringefilter procedure for processing samples for analysis of organic compounds by dai lcmsms. To understand the need for seeding in the bod test c. Odell inorganic chemistry branch chemistry research division.
Biochemical oxygen demand tdec fleming training center 012014 sep. Obviously, the bod test is not the most scientifically based test we perform. A consumers guide to bod 5 5day biochemical oxygen demand. 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. Bod test requirements by tim loftus legend has it that the 5day bod biological oxygen demand test was developed in england. Fiveday bod bod5 the bod test is a standardized test that 5 provides information regarding the organic. Since bod is a biochemical process, it is not a precise quantitative test. In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to. Test procedure the bod test takes 5 days to complete and is performed using a dissolved oxygen test kit. The bod test reflects the amount of dissolved oxygen do consumed by bacteria while oxidizing these materials. Water for bod application water purification milliporesigma. Cap with stopper and pour off excess from the water seal. Cod is the amount of oxygen required for the oxidation of total organic matter in water.
Biological oxygen demand bod is an important and widely used sum parameter to evaluate water quality. After the training the participants will be able to. Biochemical oxygen demand bod is usually expressed in mgl but can also be expressed in lbsday. Overview of the two procedures for the 5day bod bod 5 test about the official procedure the procedure specified by the united states geological survey for the bod 5 test is done in the laboratory and is quite complex to perform and difficult to control for reliable results. Measurement of biochemical oxygen demand bod free essays. Neutralized samples must be seeded for the bod test.
National field manual for the collection of waterquality. Bod incubators are widely used to perform day to day bacteriological tests in the testing laboratories. Be familiar with the use or purpose of each reagent used in the test indicator, titrant, etc. This section of chapter 5 of the national field manual for the collection of waterquality data nfm describes the field procedures for collecting smallvolume samples using a syringetip filtration method. The bod level is determined by comparing the do level of a water sample taken immediately with the do level of a water sample that has been incubated in a dark location for 5 days. These variations can be caused by a number of factors, including changes in temperature, weather, composition of.
Among the considerations for a reliable test are the following. Dissolved oxygen is essential for the life of aquatic fauna and flora, and the bod test is a measure of the ecological impact that effluent water may have on the receiving body of water river, lake, etc. 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. The respirometric method can be compared to the dilution method, and standard methods are discussed in contrast to selfmonitoring methods. Bod biochemical oxygen demand and carbonaceous bod cbod explain the following aspects of the procedure for determining bodcbod. There are, however, some concepts you should be familiar with to obtain the best quality results. Biochemical oxygen demand bod testing and measurement in water. Biological oxygen demand bod overview raw sewage may give readings in the hundreds and. These instruments are userfriendly in nature and comprise of highly developed operating systems that examine the samples carefully and helps the users to maintain accurate and reliable data. The difference between the two do levels represents the amount of oxygen required for the decomposition of any. Updated 01242020 jbb biochemical oxygen demand bod, sm 5210 b, 22. Running the biochemical oxygen demand bod test ebs. Sewage was dumped in a river and it took five days for it to reach the ocean, hence the fiveday incubation requirement in the bod method.
Difference between bod and cod definition, test method. In the presence of free oxygen, aerobic bacteria use the organic matter found in wastewater as food. Difference between bod and cod definition, test method and. Stopper each bottle taking care to avoid trapping air bubbles inside the bottles as the bottle. Therefore, do readings must be as accurate as possible to ultimately get accurate bod results.
The biochemical oxygen demand bod test is a measurement of the quantity of oxygen required by bacteria to biologically oxidize organic material under aerobic conditions. Swirl until all the mercuric sulfate has dissolved. Pdf methods for assessing biochemical oxygen demand bod. The biochemical oxygen demand bod is one of the most widely used criteria for water quality assessment. The water saturated air procedure involves storing the electrode in a sealed bod bottle containing a minimal amount of water. Carefully fill a bod bottle with sample water without making air bubbles. Even though the end result of bod testing is a final bod reading, the calculations are all based on do readings. Add 2ml of manganese sulfate to the bod bottle carefully by inserting the pipette just below the surface of water. The bod value is calculated from the depletion and the amount of sample used. Bod is the amount of oxygen consumed by bacteria while decomposing organic matter under aerobic conditions. Test procedure the bod test takes 5 days to complete and is. Cod often is used as a measurement of pollutants in wastewater and natural waters. The bod test takes 5 days to complete and is performed using a dissolved oxygen test.
It provides information about the ready biodegradable fraction of the organic load in water. Describe the test procedure for acidity including reagents, holding time, and calculation. It describes the procedure for undiluted samples whose bod must, however, lie at a low level of between 0. The determination of chemical oxygen demand in waters and. Weigh the full bod bottle and cap to the nearest 0. 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. Understanding the need and procedure for dilution and seeding in bod measurement key concepts. It is a variation of the bod test that measures the oxygen demand due to carbon based. Determination of biological oxygen demand bod in waste. The biggest challenge in the bod test is that of time. So that you can avoid the formation of air bubbles.
The change in do concentration is measured over a given period of time in water samples at a. The bod determination is an empirical test in which standardised laboratory procedures are. No dilution is required for samples whose 5day bod is less than 6 mgl. To check the procedure by determining the bod value of a standard glucoseglutamic acid sample 2. Bod is a measure for the quantity of oxygen required for the biodegradation of organic matter carbonaceous demand in water but it is affected by oxygen consumed for oxidising inorganic material such as sulphides and ferrous iron and by the amount of oxygen used. The biochemical oxygen demand bod determination is an empirical test in which standardized laboratory procedures are used to determine the relative oxygen requirements of wastewaters, ef. Mar 10, 2012 licensed to youtube by sme on behalf of epic. The bod test measures the oxygen demand due to both carbon and nitrogen based compounds. The change in do concentration is measured over a given period of time in water samples at a specified temperature. The holding time for a bod sample is 48 hours from collection. There can be confusion about bod and its relationship with dissolved oxygen do readings. Biochemical oxygen demand bod is the amount of dissolved oxygen needed i. The bod of a water sample is generally measured by incubating the sample at 20oc for 5 days in the dark room under aerobic condition in bod incubator.
Dissolved oxygen is essential for the life of aquatic fauna and flora, and the bod test is a measure of the ecological impact that effluent water may. Comparison study of different bod tests in the determination. Understanding the need and procedure for dilution and. The determination of biochemical oxygen demand is always a topic of discussion with. What you should know the actual procedure is so much more involved than the summary given above. For the airsaturated water calibration procedure, you either vigorously shake the solution or bubble air through it. Test procedure the bod test takes 5 days to complete and. Laboratory procedure completely fill two bod bottles with dilution water. In the manual, therefore, the bis procedure for measurement of bod is 3205 part 44.
The bod electrode method is suitable for determining the bod of water and wastewater. This publication is designed to provide a solid working knowledge of one of the major wastewater analytical test categories. Understanding dilution and seeding procedures in bod test. It is the rate at which organisms use the oxygen in wastewater while digesting organic matter. Appropriate protective equipment should be worn when undertaking the bod biochemical oxygen demand electrode method. To determine the biochemical oxygen demand bod of various samples of water b. Jun 07, 2017 bod refers to the biochemical oxygen demand, which measures the amount of dissolved oxygen do required by aerobic organisms to break down organic material present in a given water sample at a given temperature and specified time. The bod test is an estimate of the food available in the sample. The test has its widest application in measuring waste loadings to treatment plants and in evaluating the bodremoval. Into additional bod bottles, partially filled with dilution water, carefully mix the proper volume of sample. 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.
An extended ubod ultimate bod test that measures oxygen consumption after 60 days or more is sometimes required in wastewater permits. Biochemical oxygen demand bod is also sometimes referred to as biological oxygen demand, but the latter term is considered inappropriate by many scientists and. Other related analytical values are biochemical oxygen demand bod, total organic carbon toc, and total oxygen demand tod. The more food present in the waste, the more dissolved oxygen do will be required. To ensure proper biological activity during the bod test, a wastewater sample. Mar 17, 2015 biochemical oxygen demand bod bod is an empiric laboratory assay which measures the amount of organic matter contained in a water sample. Accurate bod measurements with electrochemical and optical probes. Bod test bottles at the laboratory of a wastewater treatment plant. The difference between the two do levels represents the. In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. Biochemical oxygen demand bod testing and measurement in. Because of imprecision inherent to the bod test, the seed contribution to do depletion could completely mask the sample contribution for low bod samples. Standard dilution technique should be applied to samples with do depletion greater than 6 mgl. Bod is a measure for the quantity of oxygen required for the biodegradation of organic matter carbonaceous demand in water but it is affected by oxygen consumed for oxidising inorganic material such as sulphides and ferrous iron and by the amount of oxygen used to oxidise.
661 501 1231 573 1306 465 901 395 1258 974 1459 456 1039 304 381 708 1181 538 123 433 1531 1565 808 1510 1547 1002 327 288 892 1008 45 44 1534 762 1185 589 40 280 586 1022 542 1116 581 1158 471