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STUDIES ON THE RELATIONSHIP BETWEEN FEED COD AND EFFLUENT COD DURING TREATMENT BY ACTIVATED SLUDGE PROCESSES T. S. Manickam, Research Assistant A. F. Gaudy, Jr., Professor Bioenvironmental Engineering Laboratories School of Civil Engineering Oklahoma State University Stillwater, Oklahoma 74074 INTRODUCTION Increasingly stringent effluent requirements emphasize the need for more "finely tuned" predictive equations for describing effluent quality in the design stage and throughout the life of a treatment facdity. The greatest advances in modeling predictive behavior have been those dealing with fluidized culture processes, such as activated sludge. These advances have been made possible because of the research of various investigators in the areas of both wastewater treatment and industrial fermentation. However, the greatest steps forward have been the adoption and the adaptation of the general "first principles" embodied in the theory of continuous culture of microorganisms which was first described (independently) in 1950 by Monod [1] and by Novick and Szdard [2] and elaborated upon by Herbert et al. [3] in 1956 and by Herbert in 1961 [4]. One prediction of the theory is that in the steady state the concentration of soluble carbon source in the reactor effluent Se is not dependent on the concentration in the feed Sj. This comes about in a once-through system because the specific growth rate M is related to Se by the Monod relationship, and also to ddution rate D. Since D can be held constant by controlling flowrate F (i.e., D = F/V), Se wdl be constant. Furthermore, since the cell yield Yt and the cell decay factor kj are biological "constants," an increase in Sj is registered only as an increase in the biomass concentration X in the system. Se in a once-through system is given in Equation 1 of Table I. If Sj is increased it does not affect p. and therefore does not affect Se. The same line of reasoning holds true for a system in which cell recycle is employed according to the model of Herbert, since the recycle cell concentration Xr is made to be dependent upon the biomass concentration X because of the selection of the concentration factor c (Xr/X = c) as a design and/or operational constant. Equation 2 is the predictive relationship for Se and it is independent of Sj. This feature of the kinetic theory has caused some concern among microbial kineticists and pollution control researchers because in continuous culture experiments some have noted an increase in Se for increased values of Sj. This matter is a source of controversy in the field [5-14]. The divergence from theory generally is not so great as to interfere with general use of the theory for predicting the useful yield of a bioculture process. However, in wastewater treatment, small divergences from the predicted Se for an increase in organic loading Sj can be important in view of the very low Se values demanded by enforcement of PL 92-500, and a number of investigators have proposed adjustments or modifications to accommodate or account for increases in Se for increased values of S;. The situation is complicated in water pollution control by the fact that the carbon source can be measured by a variety of codective or gross parameters of substrate, e.g., BOD, COD, ACOD, ATOC, and the fact that Se refers to soluble substrate in the effluent which is as yet not routinely assessed and reported in field operations. 854
Object Description
Purdue Identification Number | ETRIWC197985 |
Title | Studies on the relationship between feed cod and effluent cod during treatment by activated sludge processes |
Author |
Manickam, T. S. Gaudy, Anthony F. |
Date of Original | 1979 |
Conference Title | Proceedings of the 34th Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://e-archives.lib.purdue.edu/u?/engext,30453 |
Extent of Original | p. 854-867 |
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 | 2009-06-24 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page0854 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | STUDIES ON THE RELATIONSHIP BETWEEN FEED COD AND EFFLUENT COD DURING TREATMENT BY ACTIVATED SLUDGE PROCESSES T. S. Manickam, Research Assistant A. F. Gaudy, Jr., Professor Bioenvironmental Engineering Laboratories School of Civil Engineering Oklahoma State University Stillwater, Oklahoma 74074 INTRODUCTION Increasingly stringent effluent requirements emphasize the need for more "finely tuned" predictive equations for describing effluent quality in the design stage and throughout the life of a treatment facdity. The greatest advances in modeling predictive behavior have been those dealing with fluidized culture processes, such as activated sludge. These advances have been made possible because of the research of various investigators in the areas of both wastewater treatment and industrial fermentation. However, the greatest steps forward have been the adoption and the adaptation of the general "first principles" embodied in the theory of continuous culture of microorganisms which was first described (independently) in 1950 by Monod [1] and by Novick and Szdard [2] and elaborated upon by Herbert et al. [3] in 1956 and by Herbert in 1961 [4]. One prediction of the theory is that in the steady state the concentration of soluble carbon source in the reactor effluent Se is not dependent on the concentration in the feed Sj. This comes about in a once-through system because the specific growth rate M is related to Se by the Monod relationship, and also to ddution rate D. Since D can be held constant by controlling flowrate F (i.e., D = F/V), Se wdl be constant. Furthermore, since the cell yield Yt and the cell decay factor kj are biological "constants," an increase in Sj is registered only as an increase in the biomass concentration X in the system. Se in a once-through system is given in Equation 1 of Table I. If Sj is increased it does not affect p. and therefore does not affect Se. The same line of reasoning holds true for a system in which cell recycle is employed according to the model of Herbert, since the recycle cell concentration Xr is made to be dependent upon the biomass concentration X because of the selection of the concentration factor c (Xr/X = c) as a design and/or operational constant. Equation 2 is the predictive relationship for Se and it is independent of Sj. This feature of the kinetic theory has caused some concern among microbial kineticists and pollution control researchers because in continuous culture experiments some have noted an increase in Se for increased values of Sj. This matter is a source of controversy in the field [5-14]. The divergence from theory generally is not so great as to interfere with general use of the theory for predicting the useful yield of a bioculture process. However, in wastewater treatment, small divergences from the predicted Se for an increase in organic loading Sj can be important in view of the very low Se values demanded by enforcement of PL 92-500, and a number of investigators have proposed adjustments or modifications to accommodate or account for increases in Se for increased values of S;. The situation is complicated in water pollution control by the fact that the carbon source can be measured by a variety of codective or gross parameters of substrate, e.g., BOD, COD, ACOD, ATOC, and the fact that Se refers to soluble substrate in the effluent which is as yet not routinely assessed and reported in field operations. 854 |
Resolution | 300 ppi |
Color Depth | 8 bit |
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