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BOD Progression in Soluble Substrates -IV- A Short Term Total Oxygen Demand Test A. W. BUSCH and LESLIE GRADY, JR., Assistant Professors T. SHIVAJI RAO and E. L. SWILLEY, Research Assistant Department of Civil Engineering Rice University Houston, Texas This paper is the fourth in a series reporting results obtained in an investigation of the biochemical degradation of organic compounds. Previous papers (1), (2), (3) have defined the progression of BOD in pure soluble organic substrates, have delineated the oxidation-assimilation relationships, and nave shown the validity of solids production reactions over the broad range of biological environments. Bacterial growth and cell production have been shown to reflect the nature of the substrate oxidized, whether in BOD bottles, a Warburg apparatus, or in bio-oxidation systems called activated sludge plants. This paper shows, for pure soluble organics, how the basic relationships previously reported may be used for derivation of a short-term TOD test. TOD is defined as total oxygen demand. It is numerically equivalent to the theoretical oxygen demand. Thus for biologically degradable materials TOD is numerically equivalent to the COD or chemical oxygen demand. THEORY Theoretical oxidation equations can be written for organic compounds. Thus, glucose has a TOD of 1.07 gm/gm and glutamic acid has a TOD of 0.98 gm/gm. Previous papers (1), (2), (3) of this series have presented evidence that upon attainment of the plateau in the BOD curve, all substrate has been converted into bacterial cells of known chemical composition (C5H7NO2) with a theoretical oxygen demand of 1.414 gm/gm. Thus, at the plateau, the difference between the original substrate TOD and the exerted BOD is contained in cell material. Conversely, for any waste, measurement of plateau BOD followed by gravimetric or chemical determination of the resulting cell growth should yield the TOD value of the substrate. Since the plateau occurs within 24 to 48 hrs there is available a short term TOD test. The short-term BOD and the TOD values completely define the minimum and maximum quantities of oxygenwhich must be provided in the treatment plant and/or receiving waters (4). The slope of the short-term BOD curve shows that where soluble wastes are discharged into streams, use of the currently favored first order rates of deoxygenation is unduly optimistic and may result in nuisance conditions. EXPERIMENTAL PROCEDURE Theoretically, cell production at the plateau may be measured chemically or gravimetrically. It is pertinent to consider the magnitude of the COD and/or cell weights involved. Ordinarily only about six mg/l of the initially present dissolved oxygen can be satisfactorily utilized for bacterial uptake. The other 2.5 to three mg/l must be allotted to seed utilization - 67 -
Object Description
Purdue Identification Number | ETRIWC196107 |
Title | BOD progression in soluble substrates. IV. A short term total oxygen demand test |
Author |
Busch, Arthur Winston, 1926- Grady, Leslie Rao, T. Shivaji Swilley, E. L. |
Date of Original | 1961 |
Conference Title | Proceedings of the sixteenth Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://earchives.lib.purdue.edu/cdm4/document.php?CISOROOT=/engext&CISOPTR=7917&REC=15 |
Extent of Original | p. 67-76 |
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 | 2008-09-22 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 67 |
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 | BOD Progression in Soluble Substrates -IV- A Short Term Total Oxygen Demand Test A. W. BUSCH and LESLIE GRADY, JR., Assistant Professors T. SHIVAJI RAO and E. L. SWILLEY, Research Assistant Department of Civil Engineering Rice University Houston, Texas This paper is the fourth in a series reporting results obtained in an investigation of the biochemical degradation of organic compounds. Previous papers (1), (2), (3) have defined the progression of BOD in pure soluble organic substrates, have delineated the oxidation-assimilation relationships, and nave shown the validity of solids production reactions over the broad range of biological environments. Bacterial growth and cell production have been shown to reflect the nature of the substrate oxidized, whether in BOD bottles, a Warburg apparatus, or in bio-oxidation systems called activated sludge plants. This paper shows, for pure soluble organics, how the basic relationships previously reported may be used for derivation of a short-term TOD test. TOD is defined as total oxygen demand. It is numerically equivalent to the theoretical oxygen demand. Thus for biologically degradable materials TOD is numerically equivalent to the COD or chemical oxygen demand. THEORY Theoretical oxidation equations can be written for organic compounds. Thus, glucose has a TOD of 1.07 gm/gm and glutamic acid has a TOD of 0.98 gm/gm. Previous papers (1), (2), (3) of this series have presented evidence that upon attainment of the plateau in the BOD curve, all substrate has been converted into bacterial cells of known chemical composition (C5H7NO2) with a theoretical oxygen demand of 1.414 gm/gm. Thus, at the plateau, the difference between the original substrate TOD and the exerted BOD is contained in cell material. Conversely, for any waste, measurement of plateau BOD followed by gravimetric or chemical determination of the resulting cell growth should yield the TOD value of the substrate. Since the plateau occurs within 24 to 48 hrs there is available a short term TOD test. The short-term BOD and the TOD values completely define the minimum and maximum quantities of oxygenwhich must be provided in the treatment plant and/or receiving waters (4). The slope of the short-term BOD curve shows that where soluble wastes are discharged into streams, use of the currently favored first order rates of deoxygenation is unduly optimistic and may result in nuisance conditions. EXPERIMENTAL PROCEDURE Theoretically, cell production at the plateau may be measured chemically or gravimetrically. It is pertinent to consider the magnitude of the COD and/or cell weights involved. Ordinarily only about six mg/l of the initially present dissolved oxygen can be satisfactorily utilized for bacterial uptake. The other 2.5 to three mg/l must be allotted to seed utilization - 67 - |
Resolution | 300 ppi |
Color Depth | 8 bit |
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