Curve b is the expected dry flow do profile after implementation of pollution control measures ahmed and mohammed, 1988. Jan 10, 2018 for the love of physics walter lewin may 16, 2011 duration. The presence of sewage reduces the oxygen content of the water and increases the. The oxygen sag or oxygen deficit in the stream at any. Do sag curve q1, bod1 ss1 q2, bod2 ss2 residents industry saturation do cs travel time, days dissolved oxygen, mgl oxygen depletion initial deficit d 0. The amount of dissolved oxygen in a stream or lake can tell us a lot about its water quality. Environmental engineering ii unit i linkedin slideshare. Ee pdf notes unit 5 civil branch downloads smartworld. The net result of the oxygen demand and replenishment processes is illustrated by curve c, which is called the dissolved oxygen sag curve.
This differential equation states that the total change in oxygen deficit d is equal to the difference between the two rates of deoxygenation and. Self purification of river water prof umesh t kulkarni 2. Oxygen sag curve solved examples waste water engineering. The resulting sag curve is able to be modeled to predict the minimum oxygen concentration 5. A sag curve when an oxygen demand chemical is discharged into a river it affects the concentration of dissolved oxygen in a manner which varies with distance from the point of discharge. Tutorial on heat and oxygen transport an oxygendepleting material i. The oxygen sag curve is related to all of the foll. The general mathematical properties of point of pollution initial or reference point. It is the purpose of this paper to present a systematic analysis of the. Derive a simple mathematical model the incorporates the factors that influence the oxygen resources of a stream.
The oxygen sag curve is related to all of the following except select one. Theory and practice of water and wastewater treatment, 2nd. Pdf study of dissolved oxygen do profile in nalanda lake, sri. Elevated p50 values indicate a right shift of the curve. Discover how using computerbased mathematical models of the environment can assist in solving engineering problems. Dissolved oxygen sag curve readings for this class. Usgs scientist is measuring various waterquality conditions in holes creek at huffman park in kettering, ohio. By far the most important characteristic determining the quality of a river or stream is its dissolved. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Point source pollution external organic matter u z o. A dissolved oxygen do equation for a stream is developed in which the biochemical oxygen demand bod deoxygenation rate is described as a secondorder reaction. The self purification process of water bodies or processes involving biological, chemical and physical processes.
The solubility of oxygen in fresh water, at a pressure of 1 atmosphere, decreases with temperature as shown in figure 5. Unit v sludge treatment and disposal 9 en8592 wastewater engineering. Oxygen sag oxygen sag model one of the earliest mathematical water quality models was developed by for the o hio river b y h. Zones of pollution pollution and selfpurification of stream and changes in the aquatic. Dissolved oxygen sag analysis for a settling fields overlapping type. The oxygen sag curve is related to all of the following except. Standards for disposal methods dilution mass balance principle self purification of river oxygen sag curve deoxygenation and reaeration streeterphelps model land disposal. Oxygen sag curve fillintheblank worksheet by effler. Obviously, the place of greatest environmental concern is the do minimum. Dissolved oxygen sag use the previous estimates of the oxygen transfer coefficient, endogenous respiration rate, and fraction of bod exerted note that a different amount of bod was added for the sag curve than for the bod measurement.
Ce6605 notes environmental engineering 2 regulation 20. Ce6605 notes environmental engineering 2 regulation 20 anna university free download. Phelps model was developed to predict the dissolved oxygen concentration do in water located down. This is called the oxygen sag curve or the streeterphelps oxygen sag curve. The amount of do in water is one of the most commonly used indicators of. The phenomenon of oxygen sag is usually related to the release of organic pollutants or nutrient elements, which promote the growth of oxygen consuming. The self purification process of water bodies or processes involving biological, chemical and physical. Oxygen sag curve benoit cushmanroisin by far the most important characteristic determining the quality of a river or stream is its dissolved oxygen, do measured in mgl.
Request pdf the development of simple dissolved oxygen sag. Biochemical oxygen demand and the dissolved oxygen sag curve in a stream. The variation of the concentration of dissolved oxygen is shown in the following graph, commonly referred to as a sag curve. Oxygen depletion michigan technological university. When the actual amount of oxygen in the water is less than the saturation value given in the figure, atmospheric oxygen passes into the water at a rate which is proportional to the deficit. Sag curves occur downstream of sewage works and the like so the answer is b. Oxygen is not delivered to the tissues efficiently as the oxyhaemoglobin dissociation curve of stored blood is shifted far to the left. The derivation of the do sag equation is the objective of this article. The oxygen dissociation curve plots the % saturation against the partial pressure of oxygen, and its contribution to the total oxygen content. Please note the dotted line at the bottom of the graph. Download link is provided and students can download the anna university ce6605 environmental engineering ii ee ii syllabus question bank lecture notes syllabus part a 2 marks with answers part b 16 marks question bank with answer, all the materials are listed below for the students to make use of it and score good maximum marks with our study materials. From the curve, the oxygen deficit d and oxygenation balance 100d% in a stream after a certain lapse of time can be found out. Standards for disposal methods dilution self purification of surface water bodies oxygen sag curve land disposal sludge characterization thickening sludge digestion.
Hence the model is referred to as the streeterphelps model. Elevated p50 values indicate that hemoglobin will surrender oxygen to the tissues more easily. Mihelcic encyclopedia of life support systems eolss summary biochemical oxygen demand bod is a measure of the dissolved oxygen consumed by. Dissolved oxygen sag analysis for a settling fields. Jan 02, 2017 oxygen sag curve, zones of purification, sewage farming, sewage sickness. The p50 reflects the affinity of hemoglobin for oxygen. Jan, 2015 the resultant curve so obtained is called the oxygen sag curve or oxygen deficit curve. Oxygen sag equation for secondorder bod decay sciencedirect.
Provides an excellent balance between theory and applications in the everevolving field of water and wastewater treatment completely updated and expanded, this is the most current and comprehensive textbook available for the areas of water and wastewater treatment, covering the broad spectrum of technologies used in practice todayranging from commonly used standards to the latest state of the. Standards for disposal methods dilution mass balance principle self purification of river oxygen sag curve deoxygenation and reaeration streeterphelps model land disposal sewage farming sodium hazards soil dispersion system. View notes lecture 47 from cee 260 at university of michigan. Expert answer 100% 1 rating previous question next question transcribed image text from this question.
Four quick analysis questions follow the labelingdrawing. Derivation streeterphelps equation professor john r. Unesco eolss sample chapters environmental and ecological chemistry vol. The do sag curve and the streeterphelps equation one of the earliest mathematical water quality models was developed by for the ohio river by h.
To study and evaluate the important constants related to the oxygen sag curve of a river or streeter phelps equation. While the saturated value dos is rarely achieved, a stream can nonetheless be considered healthy as long as its dissolved oxygen do exceeds 5 mgl. Oxygen sag curves occur when the oxygen dissolved in the water is depleted. Oxygen sag curve land disposal sewage farming deep well injection soil dispersion system sludge characterization thickening sludge digestion biogas recovery sludge conditioning and dewatering disposal advances in sludge treatment and disposal text books. Model relates the rate of change of the oxygen deficit with distance to the spatial rates of oxygen. Do sag curve q1, bod1 ss1 q2, bod2 ss2 residents industry saturation do cs travel time, days dissolved oxygen, mgl oxygen depletion initial deficit d 0 oxygen addition reaertaion critical deficit dc t c. Curve b shows the reaeration process observed when oxygen is forced to dissolve in the water due to the oxygen deficit created by the biodegradation taking place. Biochemical oxygen demand and the dissolved oxygen sag curve. This paper was aimed to provide more detail explanation focusing on the development of simple dissolved oxygen do sag curve in a lowland nontidal river under steady flow condition. Oxygen demand concepts and dissolved oxygen sag in streams. In the storage solution, sagm saline, adenine, glucose, and mannitol, 2,3dpg levels are very low after 14 days. These two concurrent processes of oxygen consumption and oxygen replenishment produce an oxygen sag curve, i. 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.
So, whenever possible, download links to functioning matlab codes were. Wastewater engineering syllabus en8592 pdf free download. Picture 2 1 curve of oxygen sag characteristic is based on. The streeterphelps equation determines the relation between the dissolved oxygen concentration and the biological oxygen demand over time and is a solution to the linear first order differential equation. Rate constants for a secondorder bod equation may be evaluated by graphical or numerical methods. Oxygen sag curves the curve obtained when the concentration of dissolved oxygen in a river into which sewage or some other pollutant has been discharged is. Fundamentals of wastewater treatment and engineering. The classical streeterphelps models for dissolved oxygen do sag do not account for a significantly settleable portion about 10% in treated to about 60% in the untreated wastewater discharged of the total biochemical oxygen demand bod inputs into rivers through wastewater outfalls, and therefore, they can not be used to predict the do sag to any accuracy and rationality. The minimum lies where ddodx 0, which is found to be at. Later, as the organic matter becomes used up, the oxygen resources of the river are replenished. Pdf to text batch convert multiple files software please purchase personal. In rivers, oxygen depletion takes a special form called the dissolved oxygen sag curve. Steady state and dynamic models employed are basically developed by matlab using two mathematical functions of ode45 and pdepe.
If the streeterphelps equation is differentiated with respect to time, and set equal to zero, the time at which the minimum do occurs is expressed by. Qual2e rnodellng can be downloaded in the internet on webslte. Biochemical oxygen demand encyclopedia of life support. This is caused by the addition of anything which increases the biological oxygen demand such as biological waste and sewage. En8592 syllabus wastewater engineering regulation 2017. The do sag equation incorporates exponential integral functions. Environmental engineering 2 notes free pdf download. Scribd is the worlds largest social reading and publishing site.
The resultant curve so obtained is called the oxygen sag curve or oxygen deficit curve. Dissolved oxygen, the acquisition of raw wastewater effluent sample for bod. This video covers solved examples to find out the deficit in dissolved oxygen at a location and to calculate the critical deficit and time to critical deficit. Oxygen sag curve, zones of purification, sewage farming, sewage sickness. Mathematical models of dissolved oxygen concentration in. Introduction it is a natural process of rivers, lakes or canals to recover the rate of dissolved oxygen values of the highest concentration of oxygen which is one of the best indicators of water quality. Aug 16, 2017 this video covers solved examples to find out the deficit in dissolved oxygen at a location and to calculate the critical deficit and time to critical deficit. Physiology of haemoglobin bja education oxford academic. Quick assessment for students to make sure they understand the difference between do and bod and the different zones of pollution. The phenomenon of oxygen sag is usually related to the release of organic pollutants or nutrient elements, which promote the growth of oxygenconsuming.
Learn vocabulary, terms, and more with flashcards, games, and other study tools. This is an s shaped curve due to the alterations in hemoglobins affinity for oxygen in response to other physiologic factors. Also has students label indicator species found in each zone. Biochemical oxygen demand and the dissolved oxygen sag. For the love of physics walter lewin may 16, 2011 duration. When organic carbon is placed into a stream environment, the dissolved oxygen drops following a characteristic pattern. The p50 is the po2 at which hemoglobin is 50% saturated. Pdf on apr 1, 2016, madhubhashini makehelwala and others published. Oxygen demand concepts and dissolved oxygen sag in. The classical streeterphelps models for dissolved oxygen do sag do not account for a significantly settleable portion about 10% in treated. Lecture 4 ce 433 excerpts from lecture notes of professor m. The oxygen concentration in the river drops rapidly following the discharge of a waste containing organic matter. Multiple point source curve a is the present predicted dry flow profile with observed river sampling results. Pdf ce6605 environmental engineering ii eeii books.