Settling Velocity Grading of Particle Bound PAHs: Case of Wet Weather Flows within Combined Sewer Systems

2009 ◽  
Vol 135 (11) ◽  
pp. 1155-1160 ◽  
Author(s):  
J. Gasperi ◽  
C. Lorgeoux ◽  
R. Moilleron ◽  
M.-C. Gromaire ◽  
G. Chebbo
Keyword(s):  
Settling Velocity ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Wet Weather

Origins and characteristics of urban wet weather pollution in combined sewer systems: the experimental urban catchment “Le Marais” in Paris

1998 ◽  
Vol 37 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Marie-Christine Gromaire-Mertz ◽  
Ghassan Chebbo ◽  
Mohamed Saad
Keyword(s):  
Waste Water ◽  
Sewer System ◽  
Urban Catchment ◽  
Rainfall Events ◽  
Sources Of Pollution ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Wet Weather ◽  
Wet Weather Flow ◽  
Different Sources

An experimental urban catchment has been created in the centre of Paris, in order to obtain a description of the pollution of urban wet weather flows at different levels of the combined sewer system, and to estimate the contribution of runoff, waste water and sewer sediments to this pollution. Twenty-two rainfall events were studied from May to October 1996. Dry weather flow was monitored for one week. Roof, street and yard runoff, total flow at the catchment outlet and waste water were analysed for SS, VSS, COD and BOD5, on both total and dissolved fraction. Results show an evolution in the characteristics of wet weather flow from up to downstream: concentrations increase from the catchment entry to the outlet, as well as the proportion of particle-bound pollutants and the part of organic matter. A first evaluation of the different sources of pollution establishes that a major part of wet weather flow pollution originates from inside the combined sewer, probably through erosion of sewer sediments.

The Erosion and Movement of Sediments and Associated Pollutants in Combined Sewers

1992 ◽  
Vol 25 (8) ◽  
pp. 101-114 ◽  
Author(s):  
R. M. Ashley ◽  
D. J. J. Wotherspoon ◽  
B. P. Coghlan ◽  
I. McGregor
Keyword(s):  
Field Data ◽  
Bed Load ◽  
Surficial Sediments ◽  
Sediment Erosion ◽  
Weak Layer ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Wet Weather ◽  
Wet Weather Flow

The complex and inhomogeneous nature of sediments in sewers, and the variability of the particles and dissolved substances flowing in dry and wet weather combined sewage, make the prediction of sediment erosion and pollutant release a difficult proposition. It is apparent that the erosion of sediments in sewers can release pollutants in concentrations which exceed by many times the levels found in the various contributing sources of the sediments and pollutants, and whilst this release is normally in the form of an initial highly polluting foul flush at the start of wet weather flow, the occurrence of foul flushes has not been found to be ubiquitous, even from event to event in the same sewer. The origins of foul flushes may be attributable to the speedy erosion of a weak layer of highly concentrated surficial sediments (or bed-load) at the start of wet weather flows. Various models have been proposed, and some successfully applied to field data, to simulate the erosion and movement of sediments and associated pollutants in combined sewer systems.

Settleable Solids in a Combined Sewer System, Settling Characteristics, Heavy Metals, Efficiency of Storm Water Tanks

1993 ◽  
Vol 27 (5-6) ◽  
pp. 153-164 ◽  
Author(s):  
S. Michelbach ◽  
C. Wöhrle
Keyword(s):  
Heavy Metals ◽  
Settling Velocity ◽  
Urban Runoff ◽  
Stormwater Treatment ◽  
Sewer System ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Combined Sewer System ◽  
Water Tanks ◽  
The Relationship

Sedimentation and transportation of mineral and organic pollutions in combined sewer systems are not completely understood. For better understanding, samples of sediment, slime and urban runoff were taken from the combined sewer system of Bad Mergentheim. The settling velocity of settleable solids was measured with a settling apparatus. Typical settling curves for sediment, slime and wastewater were put together. Some of the samples were analysed for heavy metals and organic micro-pollution. By this the relationship between settling velocity and the load of heavy metals can be shown. The gained data are of interest for the design of clarifier tanks for stormwater treatment.

Contributions of wastewater, runoff and sewer deposit erosion to wet weather pollutant loads in combined sewer systems

2010 ◽  
Vol 44 (20) ◽  
pp. 5875-5886 ◽  
Author(s):  
J. Gasperi ◽  
M.C. Gromaire ◽  
M. Kafi ◽  
R. Moilleron ◽  
G. Chebbo
Keyword(s):  
Pollutant Loads ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Wet Weather

Settleable Solids in a Combined Sewer System – Measurement, Quantity, Characteristics

1992 ◽  
Vol 25 (8) ◽  
pp. 181-188 ◽  
Author(s):  
S. Michelbach ◽  
C. Wöhrle
Keyword(s):  
Heavy Metals ◽  
Settling Velocity ◽  
Organic Pollution ◽  
Stormwater Treatment ◽  
Organic Micropollutants ◽  
Sewer System ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Combined Sewer System ◽  
The Relationship

Sediment and transportation of mineral and organic pollution in combined sewer systems are not completely understood. For better understanding, samples of sediment, slime and urban runoff were taken from the combined sewer system of Bad Mergentheim. The sedimentation velocity of settleable solids was measured with a settling apparatus. Typical settling curves for sediment, slime and wastewater were compiled. Some of the samples were analysed for heavy metals and organic micropollutants. By this the relationship between settling velocity and the load of heavy metals can be shown. The gained data are of interest to size clarifier tanks for stormwater treatment.

Origin, resuspension and settling characteristics of solids transported in combined sewage

1995 ◽  
Vol 31 (7) ◽  
pp. 69-76 ◽  
Author(s):  
S. Michelbach
Keyword(s):  
Settling Velocity ◽  
Low Flow ◽  
Sewer Systems ◽  
Settling Behaviour ◽  
Major Process ◽  
Receiving Waters ◽  
Wet Weather ◽  
Different Sources ◽  
Settling Process ◽  
Dry Weather Flow

Solids in combined sewage come from different sources. During dry weather flow, organic material will settle in sewer sections having low flow velocities. Microorganisms living from solubles out of dry weather flow are growing at the sewer wall. During low rains, mineral and organic solids from the surface will be washed into the sewer systems and part will settle at the sewer bottom. During storms, all these types of solids will be resuspended and mixed into the complex suspension called “combined sewage”. After five years' research it is apparent that settling velocity is a good instrument for describing sedimentation, transportation and erosion of settleable solids. The knowledge about the transportation of solids in dry weather flow will lead to better design of sewers. During wet weather, another major process for keeping solids back from receiving waters is the settling process. Up to 70% of settleable solids will be settled in a stormwater tank designed after the German guideline A 128. With knowledge of the settling behaviour of combined sewage the design of stormwater tanks could be improved and the receiving waters better protected from sewer pollution.

Settleable Solids in a Combined Sewer System: “Settling Characteristics – Pollution Load – Stormwater Tanks”

1993 ◽  
Vol 27 (12) ◽  
pp. 187-190 ◽  
Author(s):  
S. Michelbach ◽  
C. Wöhrle
Keyword(s):  
Heavy Metals ◽  
Settling Velocity ◽  
Urban Runoff ◽  
Stormwater Treatment ◽  
Pollution Load ◽  
Sewer System ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Combined Sewer System ◽  
The Relationship

Sedimentation and transportation of mineral and organic pollutants in combined sewer systems are not completely understood. For better understanding, samples of sediment, slime and urban runoff were taken from the combined sewer system of Bad Mergentheim. The settling velocity of settleable solids was measured with a settling apparatus. Typical settling curves for sediment, slime and wastewater were put together. Some of the samples were analysed for heavy metals and organic micropollution to see the relationship between settling velocity and the load of heavy metals of settleable solids. The gained data are of interest for the design of clarifier tanks for stormwater treatment.

Separate and combined sewer systems: a long-term modelling approach

2009 ◽  
Vol 60 (3) ◽  
pp. 555-565 ◽  
Author(s):  
Giorgio Mannina ◽  
Gaspare Viviani
Keyword(s):  
Cost Benefit Analysis ◽  
Treatment Plant ◽  
Cost Benefit ◽  
Sewer System ◽  
Sewer Systems ◽  
System Versus ◽  
Combined Sewer ◽  
Wet Weather ◽  
Wet Weather Flow

Sewer systems convey mostly dry weather flow, coming from domestic and industrial sanitary sewage as well as infiltration flow, and stormwater due to meteoric precipitations. Traditionally, in urban drainage two types of sewer systems are adopted: separate and combined sewers. The former convey dry and wet weather flow separately into two different networks, while the latter convey dry and wet weather flow together. Which is the best solution in terms of cost-benefit analysis still remains a controversial subject. The present study was aimed at comparing the pollution loads discharged to receiving bodies by Wastewater Treatment Plant (WWTP) and Combined Sewer Overflow (CSO) for different kinds of sewer systems (combined and separate). To accomplish this objective, a comparison between the two systems was carried out using results from simulations of catchments characterised by different dimensions, population densities and water supply rate. The analysis was based on a parsimonious mathematical model able to simulate the sewer system as well as the WWTP during both dry and wet weather. The rain series employed for the simulations was six years long. Several pollutants, both dissolved and particulate, were modelled. The results confirmed the uncertainties in the choice of one system versus the other, emphasising the concept that case-by-case solutions have to be undertaken. Further, the compared systems showed different responses in terms of effectiveness in reducing the discharged mass to the RWB in relation to the particular pollutant taken into account.

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