Effect of Solids Property on Rates of Solids Dislodgment
Publication: Journal of Environmental Engineering
Volume 115, Issue 1
Abstract
This study examines the rates of solids dislodgment of three synthetic solids with varying degrees of adhesive characteristics, for which a parameter characterizing the ease of solids breakoff from the surface of filter grains is proposed. This parameter is determined by a technique of curve best‐fitting onto the experimentally obtained solids profiles of the backwash water. The 50% probability values of the parameters for clay/alum, ferric chloride, and clay/polymer are 0.165, 0.120 and respectively, suggesting that the order of ease of solids breakoff is clay/alum, ferric chloride, and clay/polymer. This order is also confirmed by the experimental data of bed cleaning efficiency. Furthermore, an attempt is made to formulate a model for predicting the solids profile of backwash water and the amount of solids removal from a bed cleaning operation. The model is developed based on an assumption that the rate of solids dislodgment at a given time is proportional to the specific deposit within the filter bed at that time and its proportionality constant is primarily affected by the property of the deposited solids.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Allan, L. F. (1935). “Filter sand experiments.” J. Amer. Water Works Assoc., 27, 205–219.
2.
Amirtharajah, A. (1978). “Optimum backwashing of sand filters.” J. Envir. Engrg. Div., ASCE, 104, 917–932.
3.
Amirtharajah, A. (1985). “The Interface Between Filtration and Backwashing,” Water Res., 19, 581–588.
4.
Baylis, J. R. (1937). “Experiences in filtration.” J. Amer. Water Works Assoc., 29, 1010–1048.
5.
Baylis, J. R. (1959). “Nature and effects of filter backwashing.” J. Amer. Water Works Assoc., 51, 126–156.
6.
Cleasby, J. L., and Baumann, E. R. (1977). “Backwash of granular filters used in wastewater filtration.” EPA‐600/2‐77‐016, Apr.
7.
Cookson, J. T., Jr. (1970). “Removal of submicron particles in packed beds.” Envir. Sci. and Tech., 4, 126–134.
8.
Huang, J. Y. C., and Garcia‐Maura, F. (1986). “Effect of influent property on filter performance.” J. Envir. Engrg. Div., ASCE, 112, 701–717.
9.
Hulbert, R., and Herring, F. W. (1929). “Studies on the washing of rapid filters.” J. Amer. Water Works Assoc., 21, 1445–1513.
10.
Johnson, R. L., and Cleasby, J. L. (1966). “Effect of backwash on filter effluent.” J. Sani. Engrg. Div., ASCE, 92, 215–228.
11.
Lawrence, W. C. (1932). “Further experience with high rate of filter wash.” J. Amer. Water Works Assoc., 24, 1358–1363.
12.
O'Media, C. R., and Stumm, W. (1967). “Theory of water filtration.” J. American Water Works Assoc., 59, 1393–1412.
Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 115 • Issue 1 • February 1989
Pages: 3 - 19
Copyright
Copyright © 1989 ASCE.
History
Published online: Feb 1, 1989
Published in print: Feb 1989
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.