Wastewater transfer during dry and wet weather in Parisian combined sewer

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
M. Kafi ◽  
M.C. Gromaire ◽  
M. Saad ◽  
G. Chebbo
Keyword(s):  
Great Part ◽  
Rain Event ◽  
Transport Capacity ◽  
Combined Sewer ◽  
Daily Cycles ◽  
Wet Weather ◽  
The Difference ◽  
Solid Transport ◽  
Water Volumes ◽  
Rain Events

The study of wastewater transfer in dry and wet weather was made following various approaches: in dry weather (relationship between pollutant loads and flows, evolution of the nature of particulate and dissolved pollutants, variations of VSS/SS and of SS/TKNd ratios); in wet weather (evaluation of the proportion of wastewater effluent during the rain event from conductivity and water volumes). Results obtained from dry weather show that the dilution by parasitic waters allows to explain a great part of the concentration variations observed at OPUR outlets. Moreover, the difference in the nature of wastewater produced during the day and the variation in the solid transport capacity, leading to erosion and/or sedimentation can also explain the daily cycles of wastewater concentrations. Indeed, results obtained from wet weather, show, whatever the size of the catchment, that there is direct correspondence between the volumetric and the conductivity methods. This indicates that wastewater volumes, at outlets during rain events, do not appear to be affected by the hydrodynamics of wet weather, whatever the size of the catchment.

Modelling the total ammonia impact of CSO and WWTP effluent on the receiving water

1998 ◽  
Vol 38 (10) ◽  
pp. 31-39 ◽  
Author(s):  
Peter Holzer ◽  
Peter Krebs
Keyword(s):  
Treatment Plant ◽  
Rain Event ◽  
Combined System ◽  
Sewer System ◽  
Wwtp Effluent ◽  
Fish Poison ◽  
Combined Sewer ◽  
Total Ammonia ◽  
High Concentrations ◽  
Rain Events

For 25 rain events test runs were performed on a catchment of a small town, where 40% of the person equivalents are connected to a separate sewer system and 60% to a combined one. We investigate the effects of rain events with regard to NH4-loads discharged by the wastewater treatment plant and by a combined sewer overflow. NH4-concentrations in the river caused by these loads are also discussed. NH4 is important as (i) it closely interrelates with NH3 – a fish poison – and (ii) it stands for dissolved compounds that mainly origin from the wastewater. The sewer system is simulated with three different options: with a combined water retention tank connected to the CSO structure, with a sewage retention tank at the interface between the separate and the combined system, and without any retention structure. While the sewage retention tank performs better concerning the integrated load discharged into the river, the combined sewer retention tank is more efficient in decreasing peak values and duration of high concentrations in the river. We also show that NH4 peak concentrations in the river are largely due to a wash-out effect in the main sewer at the beginning of a rain event.

scholarly journals Dynamics of pollutant discharge in combined sewer systems during rain events: chance or determinism?

2014 ◽  
Vol 69 (8) ◽  
pp. 1751-1758 ◽  
Author(s):  
A. Hannouche ◽  
G. Chebbo ◽  
C. Joannis
Keyword(s):  
Suspended Solids ◽  
Rain Event ◽  
Sewer Systems ◽  
Spatial Consistency ◽  
Combined Sewer ◽  
Diverse Origin ◽  
Deterministic Processes ◽  
Rain Events ◽  
Event Flow ◽  
Pollutant Discharge

A large database of continuous flow and turbidity measurements cumulating data on hundreds of rain events and dry weather days from two sites in Paris (called Quais and Clichy) and one in Lyon (called Ecully) is presented. This database is used to characterize and compare the behaviour of the three sites at the inter-events scale. The analysis is probed through three various variables: total volumes and total suspended solids (TSS) masses and concentrations during both wet and dry weather periods in addition to the contributions of diverse-origin sources to event flow volume and TSS load values. The results obtained confirm the previous findings regarding the spatial consistency of TSS fluxes and concentrations between both sites in Paris having similar land uses. Moreover, masses and concentrations are proven to be correlated between Parisian sites in a way that implies the possibility of some deterministic processes being reproducible from one catchment to another for a particular rain event. The results also demonstrate the importance of the contribution of wastewater and sewer deposits to the total events' loads and show that such contributions are not specific to Paris sewer networks.

Caractérisation des eaux usées de débordements de réseau unitaire

1985 ◽  
Vol 12 (3) ◽  
pp. 527-537 ◽  
Author(s):  
Paul Lessard ◽  
Pierre Lavallée
Keyword(s):  
Water Quality ◽  
Rain Event ◽  
Combined Sewer Overflows ◽  
Drainage Basins ◽  
Combined Sewer ◽  
Different Types ◽  
Rain Events ◽  
The Impact ◽  
The City

In 1981, the City of Québec signed a protocol with the Québec Ministry of Environment permitting the study of the impact of combined sewer overflows (CSO) during rain periods on the St-Charles River. One of the main study objectives was to characterize CSO, both quantitatively and qualitatively. Five main drainage basins, representative of the study area, were selected and sampled during nine rain events. Certain appraisals were made to explain the importance of the water quality variations during rain events in combined sewers, dry weather period influence on runoff quality, and "first-flush" phenomenon. Two principal conclusions have been drawn from these data: (1) the major part of the pollutant load routed through a combined sewer network during a rain event is generated by surface runoff and dragging of sewage deposits and (2) the overall water quality of CSO doesn't seem to vary much from one basin to another, even if the percentages associated with different types of land use (residential, commercial, industrial, etc.) are different. Key words: urban runoff, combined sewer overflow, rainfall, quality, concentration, load.

Urban tracers for the characterization of particle transport processes in an agricultural catchment

2020 ◽  
Author(s):  
Clarissa Glaser ◽  
Christiane Zarfl ◽  
Hermann Rügner ◽  
Amelia Lewis ◽  
Marc Schwientek
Keyword(s):  
Particle Flux ◽  
Suspended Particle ◽  
Sampling Site ◽  
Treatment Plant ◽  
Transport Processes ◽  
Rain Event ◽  
Particle Loading ◽  
Combined Sewer ◽  
Particle Exchange ◽  
Solid Transport

<p>Well-established relations between concentrations of total suspended solids (TSS) and the hydrophobic polycyclic aromatic hydrocarbons (PAHs) in bulk water samples make PAH ideal tracers to understand water and solid transport in catchments during high discharge events. In the study presented here, we trace particle-bound PAH concentrations in the Ammer River, Germany (annual mean discharge of 0.87 m³ s<sup>-1</sup>), during a rain event to deepen knowledge on particle origin and hydrological processes in the catchment. High-resolution temporal monitoring of discharge, TSS, particle characteristics, and PAHs was conducted over the course of an event at two sampling sites at the Ammer River. The sampling sites are located in the upper catchment and ~ 8km downstream of the upper sampling site at the outlet of the gauged catchment (134 km²), while the downstream sampling sites integrates inflowing water from tributaries and a wastewater treatment plant. High PAH particle loading demonstrates that particles in the river originate mainly from urban areas, introduced into the stream via combined sewer systems located in the upper catchment. These particles dominate the suspended particle flux over the temporal course of the event. Despite the integral suspended particle flux being nearly constant in between both sampling sites, particle quality changes which is represented by a decreased integral PAH flux and an increasing proportion of particulate organic carbon in the suspended particles. Decrease of PAH particle loading in the downstream direction suggest dilution by ‘cleaner’ particles from either un- or less contaminated or possibly leached sediments entering into the river. This shows that particle exchange between suspended and river bed sediments is more pronounced in downstream direction, demonstrating that sediment mobilisation plays a role for the overall particle flux. These results suggest that the catchment response of the Ammer River regarding the particle flux during rainfall is mainly dominated by the combined sewer system though particle exchange processes are also relevant. Urban tracers are hence helpful for understanding solid transport in catchments.</p>

Spatial variability of polycyclic aromatic hydrocarbon load of urban wet weather pollution in combined sewers

2006 ◽  
Vol 54 (6-7) ◽  
pp. 185-193 ◽  
Author(s):  
J. Gasperi ◽  
R. Moilleron ◽  
G. Chebbo
Keyword(s):  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Spatial Variability ◽  
Spatial Scales ◽  
Research Programme ◽  
Rain Event ◽  
First Results ◽  
Polycyclic Aromatic ◽  
Wet Weather ◽  
Rain Events

In Paris, the OPUR research programme created an experimental on-site observatory of urban pollutant loads in combined sewer systems in order to characterise the dry and wet weather flows at different spatial scales. This article presents the first results on the spatial variability of the polycyclic aromatic hydrocarbon (PAH) load during wet weather flow (WWF). At the scale of a rain event, investigations revealed that (i) PAH concentrations were relatively homogenous whatever the spatial scale and were greater than those of the dry weather flow (DWF), (ii) PAH distributions between dissolved and particulate phases were constant, and (iii) PAH fingerprints exhibited a similar pattern for all catchments. Moreover, an evaluation of the contribution of DWF, runoff and erosion of sewer deposits to WWF load was established. According to the hypothesis on the runoff concentration, the contributions were evaluated at 14, 8 and 78%, respectively, at the scale of the Marais catchment. For all the catchments, the runoff contribution was found quite constant and evaluated at approximately 10%. The DWF contribution seems to increase with the catchment area, contrary to the sewer erosion contribution, which seems to decrease. However, this latter still remains an important source of pollution. These first trends should be confirmed and completed by more investigations of rain events.

CSO Modelling Considering Moving Storms and Tipping Bucket Gauge Failures

2007 ◽  
Vol 2 (1) ◽  
Author(s):  
M. Hochedlinger ◽  
W. Sprung ◽  
H. Kainz ◽  
K. König
Keyword(s):  
Hydrological Models ◽  
Rain Intensity ◽  
Hydrodynamic Models ◽  
Data Intensive ◽  
Storm Flow ◽  
Cell Velocity ◽  
Combined Sewer ◽  
Moving Direction ◽  
The Difference

The simulation of combined sewer overflow volumes and loads is important for the assessment of the overflow and overflow load to the receiving water to predict the hydraulic or the pollution impact. Hydrodynamic models are very data-intensive and time-consuming for long-term quality modelling. Hence, for long-term modelling, hydrological models are used to predict the storm flow in a fast way. However, in most cases, a constant rain intensity is used as load for the simulation, but in practice even for small catchments rain occurs in rain cells, which are not constant over the whole catchment area. This paper presents the results of quality modelling considering moving storms depending on the rain cell velocity and its moving direction. Additionally, tipping bucket gauge failures and different corrections are also taken into account. The results evidence the importance of these considerations for precipitation due the effects on overflow load and show the difference up to 28% of corrected and uncorrected data and of moving rain cells instead of constant raining intensities.

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.

Technical solutions envisaged in managing solids in combined sewer networks

1996 ◽  
Vol 33 (9) ◽  
pp. 237-244 ◽  
Author(s):  
Ghassan Chebbo ◽  
Dominique Laplace ◽  
André Bachoc ◽  
Yves Sanchez ◽  
Benoit Le Guennec
Keyword(s):  
Large Scale ◽  
Suspended Solids ◽  
Drainage Area ◽  
Bed Load ◽  
Urban Drainage ◽  
Combined Sewer ◽  
Wet Weather ◽  
Technical Solutions ◽  
Dry Weather Flow ◽  
Sewer Networks

Solids in combined sewer networks represent two important technical questions: - the clogging of man-entry sewers, and - pollution in urban wet weather discharges, whose main vectors are generally suspended solids. In this paper, we shall present first, curative technical solutions which avoid or remove deposits in man-entry sewers. We shall discuss the partial extraction of the largest solids; selective trapping of bed load solids, which form deposits; and the displacement of deposits using dry weather flow flushing waves. We shall then examine technical solutions to control pollution in urban wet weather discharges. This will show that decantation is an efficient means of fighting pollution. However, it is not always feasible because it involves large scale investments. Complementary methods should, therefore, be developed and used at different points in the water's passage through an urban drainage area.

Reliability Analysis of Jack-Up Platforms Based on Fatigue Degradation

2002 ◽  
Author(s):  
Naser Shabakhty ◽  
Pieter van Gelder ◽  
Hotze Boonstra
Keyword(s):  
Service Time ◽  
Great Part ◽  
Fatigue Reliability ◽  
Original Design ◽  
Operational Conditions ◽  
Stress Fluctuation ◽  
The Difference ◽  
Offshore Industry ◽  
Jack Up ◽  
Load Conditions

Generally, jack-up structures are used for production drilling and exploration of hydrocarbons. The combination of mobility and the behavior as a fixed structure in operational conditions has made it an important structure in the offshore industry over the last 40 years. When a jack-up structure has been in operation for a great part of its original design-life and intention is there to extend the usage of this structure at a specific location, an investigation on fatigue degradation of the structure is an essential factor that has to be carried out before taking any decision. Fatigue is the process of damage accumulation in material due to stress fluctuation caused by variation of loads in service time. The fatigue failure occurs when accumulated damage has exceeded a critical level. In this paper, the remaining fatigue capacity of the jack-up structure is considered as an indicator for adequate use of the structure. It can be specified based on the difference between design-fatigue and fatigue experienced by the structure. The design-fatigue can be determined based on fluctuation of loads during the lifetime of the structure and experienced fatigue is specified by the load conditions, which the structure has experienced during its service time. When the information on the load conditions which the structure has experienced in its service time is available or known precisely, determination of the remaining fatigue capacity could be carried out by using the Palmgren–Miner’s rule. In practice, uncertainties are present in loads and characteristics of material. Hence it will be reasonable to determine the remaining fatigue reliability of the structure by the reliability methods. In this paper, based on a crack propagation approach and achieved information from inspection, it is shown that the remaining fatigue reliability of jack-up structures could be determined and updated by using a Bayesian procedure in the duration of the service time.

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