Nature and Dynamics of Water Sediment Interface in Combined Sewers
Publication: Journal of Environmental Engineering
Volume 127, Issue 3
Abstract
The measurement of suspended solid concentration profiles in dry weather wastewater of the “Le Marais” combined sewer network, Paris, has shown an increase in concentration in the lower part of the sewer's flow (1–3 g/L). To obtain a precise description of the composition of the water-sediment interface, an observation system was set up, which showed that an immobile layer composed of fibers and organic matter formed at the bottom of trunks over the coarse mineral deposits. The concentration profiles obtained result from the removal of this layer by aspiration. Samples were taken from this organic layer using a specially adapted system. The accumulation rate of the organic layer is 215 g/(m2⋅day). The particles of this organic layer are heavily loaded with pollutants (volatile solids to suspended solids = 66–75%). This layer is located at points where the shear stress is <0.1 N/m2. Flush experiments have shown that it can be eroded by small rainfall events. When these results are extrapolated over the whole catchment area by mapping the organic layer, they show that the organic layer is stored in the same quantities as the mass eroded during a rainfall event in the sewer system and it can therefore contribute to pollution in urban storm-water discharge.
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References
1.
Ahyerre, M. ( 1999). “Bilans et mécanismes de migration de la pollution organique en réseau d'assainissement unitaire.” PhD thesis, University of Paris, Paris (in French).
2.
Arthur, S. ( 1996). “Near bed solid transport in a combined sewer network.” PhD thesis, University of Abertay, Dundee, U.K.
3.
Arthur, S., and Ashley, R. ( 1998). “The influence of near bed solids transport on first foul flush in combined sewers.” Water Sci. and Technol., 25(8), 1–12.
4.
Association Française de Normalisation. (AFNOR). ( 1986). Eaux, méthodes d'essasi.
5.
Chebbo, G. ( 1992). “Solides des rejets pluviaux urbains, caractérisation et traitabilité.” PhD thesis, Ecole Nationale des Ponts et Chaussées, spécialité Sciences et Techniques de l'Environnement (in French).
6.
Coleman, N. L. (1969). “A new examination of sediment suspension in open channels.”J. Hydr. Res., Delft, The Netherlands, 7(1), 61–82.
7.
Crabtree, R. W. ( 1989). “Sediments in sewers.” J. IWEM, 3.
8.
Gromaire, M. C. ( 1998). “La pollution des eaux pluviales urbaines en réseau d'assainissement unitare caractéristiques et origines.” PhD thesis, Ecole Nationale des Ponts et Chaussées, spécialité Sciences et Techniques de l'Environnement (in French).
9.
Gromaire-Mertz, M. C., Chebbo, G., and Saad, M. ( 1998). “Origins and characteristics of urban wet weather pollution in combined sewer systems: The experimental catchment (Le Marais) in Paris.” Water Sci. and Technol., 37(1), 35–45.
10.
Krejci, V. L., Dauber, and Gujer, W. ( 1987). “Contribution of different sources to pollutant loads in combined sewers.” Proc., 4th Int. Conf. in Urban Storm Drain., IARH, 34–39.
11.
Lucas-Aiguier, E., Chebbo, G., Bertrand Krajewski, J. L., Gagné, B., and Hedges, P. ( 1998). “Analysis of the methods for determining the settling characteristics of sewage stormwater solids.” Water Sci. and Technol., 37(1), 53–61.
12.
Ristenpart, E., Ashley, R. M., and Uhl, M. ( 1995). “Organic near-bed fluid and particulate transport in combined sewers.” Water Sci. and Technol., 31(7), 61–68.
13.
Rouse, H. ( 1937). “Experiments on the mechanics of sediment suspension.” Proc., 5th Int. Congr. of Appl. Mech., Wiley, New York.
14.
Schlütter, F. ( 1998). “Numerical modelling of hydraulic, hydraulic conditions and sediment transport in the urban catchment Le Marais.” Rep., Ecole Nationale des Ponts et Chaussées, Paris.
15.
Tian, C. S. ( 1995). “Velocity and turbulence distribution in non-uniform and unsteady open-channel flow.” PhD thesis, Ecole Polytechnique fédérale de Lausanne.
16.
Verbank, M. A. ( 1993). “Identification of the depth dependent transportation of particulate solids in dry weather sewage flows.” Proc., Int. Conf. on Storm Urban Drain.
17.
Verbank, M. A. ( 1995). “Capturing and releasing settleable solids—The significance of dense undercurrents in combined sewer flows.” Water Sci. and Technol., 31(7), 85–93.
18.
Yalin, M. S. ( 1976). Mechanics of sediment transport, Queens University, Ont., Canada.
Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 127 • Issue 3 • March 2001
Pages: 233 - 239
History
Received: Feb 15, 2000
Published online: Mar 1, 2001
Published in print: Mar 2001
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