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Comparison of BOD Exertion in a Simulated Stream and in Standard BOD Bottles W. P. ISAACS, Associate Professor Sanitary Engineering Department New Mexico State University University Park, New Mexico A. F. GAUDY, JR., Professor Civil Engineering Department Oklahoma State University Stillwater, Oklahoma INTRODUCTION Today the measurement of changes in dissolved oxygen concentration occurring in a polluted system can be accomplished quite accurately; however, the intricate biological kinetics which determine the course of deoxygenation are at present only partially explained. First order reaction kinetics have been applied almost exclusively in the past to describe the exertion of BOD in receiving streams. The standard BOD bottle test has been used to define biological deoxygenation regardless of the particular process or system being considered, although the technique was originally intended for use in predicting the course of oxygen utilization and oxygen recovery in receiving streams; i. e., in relatively dilute systems. Its use in conjunction with the reaeration equation has been accepted for many years to predict the oxygen sag curve in receiving streams. In using the sag equation, the deoxygenation constant, ki, determined in the BOD bottle, is assumed to be equal to the value of kj in the receiving stream. Most often the re- aeration constant, k2, is determined indirectly by substituting the value of ki, determined using the BOD bottle technique, and other parameters into the sag equation and solving for k2. In general, it may be said that the applicability of the sag equation has not been experimentally proven for the conditions assumed in its development, and there are many questionable aspects concerning its applicability. For example, the effect of turbulence and mixing upon metabolic activity has not been precisely defined, and there is no certainty that the ki value obtained in the BOD bottle is valid for the receiving stream or for a turbulent system. The effect of turbulence and mixing on biological activity has received some investigational attention (1, 2); however, the complexity of the problem has made separation of the variables involved quite difficult. Furthermore, the effect of concentration of biological solids or initial seeding concentration on deoxygenation kinetics has been only partially delineated with respect to kinetic order and kinetic discontinuities which may appear in the BOD exertion curve (3,4). Also, in natural streams bacterial deoxygenation and physical reaeration are not the only factors which contribute to the oxygen balance. Photosynthesis and algal respiration, as well as benthal demands may play an important but as yet relatively unexplored role in determining the course of the DO sag for any particular reach of stream. It would appear that controlled experimentation in which each of the contributing mechanisms can be separately studied will almost certainly be required before the most useful equations) of predictive value can be devised. During the course of an investigation made by the authors to determine factors - 165 -
Object Description
Purdue Identification Number | ETRIWC196716 |
Title | Comparison of BOD exertion in a simulated stream and in standard BOD bottles |
Author |
Isaacs, W. P. (Willie P.) Gaudy, Anthony F. |
Date of Original | 1967 |
Conference Title | Proceedings of the 22nd Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://earchives.lib.purdue.edu/u?/engext,14179 |
Extent of Original | p. 165-182 |
Series |
Engineering extension series no. 129 Engineering bulletin v. 52, no. 3 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Date Digitized | 2009-05-20 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 165 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | Comparison of BOD Exertion in a Simulated Stream and in Standard BOD Bottles W. P. ISAACS, Associate Professor Sanitary Engineering Department New Mexico State University University Park, New Mexico A. F. GAUDY, JR., Professor Civil Engineering Department Oklahoma State University Stillwater, Oklahoma INTRODUCTION Today the measurement of changes in dissolved oxygen concentration occurring in a polluted system can be accomplished quite accurately; however, the intricate biological kinetics which determine the course of deoxygenation are at present only partially explained. First order reaction kinetics have been applied almost exclusively in the past to describe the exertion of BOD in receiving streams. The standard BOD bottle test has been used to define biological deoxygenation regardless of the particular process or system being considered, although the technique was originally intended for use in predicting the course of oxygen utilization and oxygen recovery in receiving streams; i. e., in relatively dilute systems. Its use in conjunction with the reaeration equation has been accepted for many years to predict the oxygen sag curve in receiving streams. In using the sag equation, the deoxygenation constant, ki, determined in the BOD bottle, is assumed to be equal to the value of kj in the receiving stream. Most often the re- aeration constant, k2, is determined indirectly by substituting the value of ki, determined using the BOD bottle technique, and other parameters into the sag equation and solving for k2. In general, it may be said that the applicability of the sag equation has not been experimentally proven for the conditions assumed in its development, and there are many questionable aspects concerning its applicability. For example, the effect of turbulence and mixing upon metabolic activity has not been precisely defined, and there is no certainty that the ki value obtained in the BOD bottle is valid for the receiving stream or for a turbulent system. The effect of turbulence and mixing on biological activity has received some investigational attention (1, 2); however, the complexity of the problem has made separation of the variables involved quite difficult. Furthermore, the effect of concentration of biological solids or initial seeding concentration on deoxygenation kinetics has been only partially delineated with respect to kinetic order and kinetic discontinuities which may appear in the BOD exertion curve (3,4). Also, in natural streams bacterial deoxygenation and physical reaeration are not the only factors which contribute to the oxygen balance. Photosynthesis and algal respiration, as well as benthal demands may play an important but as yet relatively unexplored role in determining the course of the DO sag for any particular reach of stream. It would appear that controlled experimentation in which each of the contributing mechanisms can be separately studied will almost certainly be required before the most useful equations) of predictive value can be devised. During the course of an investigation made by the authors to determine factors - 165 - |
Resolution | 300 ppi |
Color Depth | 8 bit |
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