Using Small Holding Tanks to Reduce Pollution in Narrow Estuaries
Publication: Journal of Hydraulic Engineering
Volume 124, Issue 2
Abstract
Discharging effluent into slow-moving water as the tide turns results in a pollution surge. The use of a holding tank makes it possible to adjust the rate of release into the estuary and to alleviate the severity of the pollution surges associated with successive turns of the tide. Extremely large holding tanks permit the elimination of pollution surges. However, tanks a tenth of that size can get the peak pollution within a factor two of the ultimate ideal. If the holding tank volume corresponds to the pollutant supply for a short time 2τH, then the tank is first used at a time −τH before slack water. The filling rate is linearly increased to match the supply rate at slack water, with the tank one-quarter filled. Until time τH the filling rate is kept maximal. Then the filling rate is decreased linearly, reaching zero at 2τH when the tank is full. The tank is emptied at a linearly increasing rate until 4τH when it is empty. This optimal tank usage flattens the pollution surge between times −τH and 4τH.
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References
1.
Bikangaga, J. H., and Nassehi, V.(1995). “Application of computer modeling techniques to the determination of optimum effluent discharge policies in tidal water systems.”Water Res., 29, 2367–2375.
2.
Giles, R. T.(1995). “Optimal strategies for discharging pollutants into narrow estuaries.”Water Res., 29, 563–569.
3.
Gould, D. J., and Munro, D. (1981). “Relevance of microbial mortality to outfall design.”Coastal discharges, Thomas Telford, London, U.K., 45–50.
4.
Holley, E. R.(1969). “Difference modeling of stream pollution.”J. Sanitary Engrg. Div., ASCE, 95(5), 968–972.
5.
Kay, A.(1990). “Advection-diffusion in reversing and oscillating flows. 1: The effect of a single reversal.”IMA J. Appl. Math., 45(2), 115–137.
6.
Li, W. H., and Kozlowski, M. E.(1974). “DO-sag in oscillating flow.”J. Envir. Engrg. Div., ASCE, 100(4), 837–854.
7.
Macdonald, G. J., and Weisman, R. N.(1977). “Oxygen sag in a tidal river.”J. Envir. Engrg. Div., ASCE, 103(3), 473–488.
8.
Smith, R.(1993). “Optimum use of holding tanks to avoid pollution surges in narrow estuaries.”IMA J. Appl. Mathematics, 51(2), 187–199.
9.
Webb, T., and Tomlinson, R. B.(1992). “Design procedures for effluent discharge to estuaries during ebb tide.”J. Envir. Engrg., ASCE, 118(3), 338–362.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 124 • Issue 2 • February 1998
Pages: 117 - 122
Copyright
Copyright © 1998 American Society of Civil Engineers.
History
Published online: Feb 1, 1998
Published in print: Feb 1998
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