Conventional and AWT Mixed-Liquor Settling Characteristics
This article has a reply.
VIEW THE REPLYPublication: Journal of Environmental Engineering
Volume 127, Issue 3
Abstract
Settling characteristics of mixed liquor from seven advanced wastewater treatment (AWT) and two conventional wastewater treatment facilities in the Tampa Bay Metropolitan Area were evaluated. An algorithm was developed that relates zone settling velocity (Vs) of the mixed liquor to initial mixed-liquor suspended solids (MLSS) concentration and unstirred sludge volume index (uSVI) of the mixed liquor. Two-tailed, paired comparison, Student's t-tests indicated there was no significant difference between the sludge volume index (SVI) as measured in a 1 L unstirred graduated cylinder and that measured in a stirred, 28 L Plexiglas column. A secondary clarifier operating diagram is presented that can be used by engineers and operators in the design and operation of secondary clarifiers. Bye and Dold's model could be used to predict the SVIs of the mixed liquors evaluated in this study.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Benefield, L. D., and Randall, C. W. ( 1980). Biological process design for wastewater treatment, Prentice-Hall, Englewood Cliffs, N.J.
2.
Biological and chemical systems for nutrient removal. (1998). Water Environment Federation, Alexandria, Va., 136–156.
3.
Box, G. E. P., Hunter, W. G., and Hunter, J. S. ( 1978). Statistics for experimenters, Wiley, New York.
4.
Bye, C. M., and Dold, P. L. ( 1998). “Sludge volume index settleability measures: effects of solids characteristics and test parameters.” Water Envir. Res., 70, 87.
5.
Coe, H. S., and Clevenger, G. H. ( 1916). “Methods of determining the capacities of slime settling tanks.” Trans. Am. Inst. of Min. Engrs., 55, 356.
6.
Daigger, G. T. ( 1995). “Development of refined clarifier operating diagrams using an updated settling characteristics database.” Water Envir. Res., 67, 95.
7.
Daigger, G. T., and Roper, R. E. ( 1985). “The relationship between SVI and activated sludge settling characteristics.” J. Water Pollution Control Fedn., 57, 859.
8.
Dick, R. I. ( 1967). “Fundamental aspects of sedimentation, part 2.” Water and Waste Engrg., 6, 44.
9.
Dick, R. I. ( 1976). “Folklore in the design of final settling tanks.” J. Water Pollution Control Fedn., 48, 633.
10.
Dick, R. I., and Ewing, B. B. (1967). “Evaluation of activated sludge thickening theories.”J. Sanit. Engrg. Div., ASCE, 93(4), 9.
11.
Dick, R. I., and Young, K. E. ( 1972). “Analysis of thickening performance of final settling tanks.” Proc., 27th Industrial Waste Conf., Purdue University, West Lafayette, Ind., 33.
12.
Hermanowicz, S. W. ( 1998). “Secondary clarification of activated sludge: development of operating diagrams.” Water Envir. Res., 70, 10.
13.
Keinath, T. M. ( 1990). “Diagram for designing and operating secondary clarifiers according to the thickening criterion.” Res. J. Water Pollution Control Fedn., 62, 254.
14.
Keinath, T. M., Ryckman, M. D., Dana, C. H., and Hofer, D. A. (1977). “Activated sludge-unified system design and operation.”J. Envir. Engrg. Div., ASCE, 103(5), 829–849.
15.
Kynch, G. J. ( 1952). “A theory of sedimentation.” Trans., Faraday Soc., 48, 166.
16.
Langslet, O. R. ( 1990). A2/O proposal for Hillsborough County, Florida, Air Products and Chemicals, Inc.
17.
Randall, C. W., Barnard, J. L., and Stensel, H. D. ( 1992). Design and retrofit of wastewater treatment plants for biological nutrient removal, Technomic Publishing, Lancaster, Pa.
18.
Reynolds, T. D., and Richards, P. A. ( 1996). Unit operations and processes in environmental engineering, 2nd Ed., PWS Publishing Co., Boston.
19.
Standard methods for the examination of waste and wastewater. (1992). 18th Ed., American Public Health Association, Washington, D.C.
20.
Standard methods for the examination of waste and wastewater. (1998). 20th Ed., American Public Health Association, Washington, D.C.
21.
U.S. Environmental Protection Agency (U.S. EPA). ( 1993). “Manual nitrogen control.” EPA/625/5-93, Washington, D.C., 249–311.
22.
Veslind, P. A. (1968). “Evaluation of activated sludge thickening theories.”J. Sanit. Engrg. Div., ASCE, 94(1), 185.
23.
Vilagos, J. L. ( 1997). “Mixed liquor settling characteristics in single and separate sludge activated sludge systems.” MS project, University of South Florida, Tampa, Fla.
24.
Wahlberg, E. J. ( 1987). “Development of settling flux curves using SVI.” MS thesis, Clemson University, Clemson, S.C.
25.
Wahlberg, E. J., and Keinath, T. M. ( 1988). “Development of settling flux curves using SVI.” J. Water Pollution Control Fedn., 60, 2095.
26.
Wastewater engineering: disposal, treatment, and reuse. (1991). 3rd Ed., McGraw-Hill, New York.
27.
Yoshioka, N. et al. ( 1957). “Continuous thickening of homogenous flocculated slurries.” Chem. Engrg., 21, 66.
Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 127 • Issue 3 • March 2001
Pages: 249 - 258
History
Received: Dec 16, 1999
Published online: Mar 1, 2001
Published in print: Mar 2001
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.