Continuous Flow Residence Time Distribution Function Characterization
Publication: Journal of Environmental Engineering
Volume 123, Issue 2
Abstract
Disinfection contactors are frequently characterized using tracer studies to determine macromixing patterns. For some applications, such as compliance with the surface water treatment rule, this information can be interpreted directly without much analysis. However, when tracer studies are performed to characterize residence time distributions for design purposes, this information is frequently analyzed using a method of moments approach. This paper shows that the method of moments approach, when compared to a nonlinear regression approach, produces a biased estimate of mean residence time and dimensionless variance, and one with a greater mean square error. The amount of bias in moments estimators is significant in a numerical sense, and leads to qualitatively poor estimation of the resulting residence time distribution. Examples are given of characterization of a pilot-scale chlorine contactor and a pilot-scale ozone contactor.
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References
1.
Aris, R., and Amundson, N. R.(1957). “Some remarks on longitudinal mixing or diffusion in fixed beds.”AIChE J., 3(2), 280–282.
2.
Bartholomew, D. J. (1983). “Isotonic inference.”Encyclopedia of statistical sciences, S. Kotz and N. L. Johnson, eds., John Wiley & Sons, Inc., New York, N.Y., 260–265.
3.
Bates, D. M., and Watts, D. G. (1988). Nonlinear regression analysis and its applications. John Wiley & Sons, Inc., New York, N.Y.
4.
Britt, H. I., and Luecke, R. H.(1973). “The estimation of parameters in nonlinear, implicit models.”Technometrics, 15(2), 233–247.
5.
Buffham, B. A., and Mason, G.(1993). “Holdup and dispersion: tracer residence times, moments and inventory measurements.”Chemical Engrg. Sci., 48(23), 3879–3887.
6.
Danckwerts, P. V.(1958). “The effect of incomplete mixing on homogeneous reactions.”Chemical Engrg. Sci., 8(2), 93–102.
7.
Haas, C. N.(1988). “Micromixing and dispersion in chlorine contact chambers.”Envir. Technol. Letters, 9(1), 35–44.
8.
Haas, C. N.(1989). “Error in variables parameter estimation.”J. Envir. Engrg., ASCE, 115(1), 259–264.
9.
Haas, C. N., et al. (1995). Development and validation of rational design methods of disinfection. AWWARF, Denver, Colo.
10.
Halfon, E.(1985). “Regression methods in ecotoxicology: a better formulation using the geometric mean functional regression.”Envir. Sci. Technol., 19(9), 747–749.
11.
Johnson, N. L., Kotz, S., and Balakrishnan, N. (1994). Continuous univariate distributions. Wiley Interscience, New York, N.Y.
12.
Lawler, D. F., and Singer, P. C.(1993). “Analyzing disinfection kinetics and reactor design: a conceptual approach versus the SWTR.”J. AWWA, 85(11), 67–76.
13.
Martin, N., Benezet-Toulze, M., Laplace, C., Faivre, M., and Langlais, B.(1992). “Design and efficiency of ozone contactors for disinfection.”Ozone Sci. and Engrg., 14(5), 391–405.
14.
MATLAB. (1994). The MathWorks Inc., Natick, Mass.
15.
Michelsen, M. L.(1972). “A least-squares method for residence time distribution analysis.”Chemical Engrg. J., 4(2), 171–179.
16.
Nauman, E. B., and Buffham, B. A. (1983). Mixing in continuous flow systems. John Wiley & Sons, Inc., New York, N.Y.
17.
Roustan, M., Stambolieva, Z., Duget, J., Wable, O., and Mallevialle, J.(1991). “Influence of hydrodynamics on giardia cyst inactivation by ozone. Study by kinetics and by `CT' approach.”Ozone Sci. and Engrg., 13(4), 451–462.
18.
Stover, E. L., Haas, C. M., Rakness, K. L., and Scheible, O. K. (1986). Design manual: municipal wastewater disinfection. U.S. Environmental Protection Agency, Cincinnati, Ohio.
19.
Teefy, S. M., and Singer, P. C.(1990). “Performance and analysis of tracer tests to determine compliance of a disinfection scheme with the SWTR.”J. AWWA, 82(12), 88–98.
20.
Trussell, R. R., and Chao, J.-L.(1977). “Rational design of chlorine contact facilities.”J. Water Pollution Control Fed., 49(7), 659–667.
21.
Westerterp, K. A., van Swaaij, W. P. M., and Beenackers, A. A. C. M. (1984). Chemical reactor design and operation. John Wiley and Sons, Inc., Chichester, U.K.
Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 123 • Issue 2 • February 1997
Pages: 107 - 114
Copyright
Copyright © 1997 American Society of Civil Engineers.
History
Published online: Feb 1, 1997
Published in print: Feb 1997
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