Simulation of the Impact of Combined Sewer Overflow on Rivers

1984 ◽  
Vol 15 (4-5) ◽  
pp. 325-332
Author(s):  
Niels Bent Johansen ◽  
Thorkild Hvitved-Jacobsen ◽  
Poul Harremoës
Keyword(s):  
Small Rivers ◽  
Combined Sewer Overflows ◽  
Quality Model ◽  
Traditional Design ◽  
Operational Design ◽  
Combined Sewer ◽  
Critical Oxygen ◽  
The Impact ◽  
Independent Parameters ◽  
Runoff Model

Combined sewer overflows can in some cases cause critical oxygen concentrations in small rivers. The traditional design criteria for the overflow structures is not specificly related to this effect. By combination of a long historical rain series, a runoff model and a river quality model, it has been possible to achieve operational design diagrams for overflow structures. The diagrams are statistically based and relate the independent parameters for the catchment, the overflow structure and the river to the effect in question, the oxygen concentration.

Causal Stochastic Simulation of Dissolved Oxygen Depletion in Rivers Receiving Combined Sewer Overflows

1994 ◽  
Vol 29 (1-2) ◽  
pp. 191-198 ◽  
Author(s):  
K. Schaarup-Jensen ◽  
T. Hvitved-Jacobsen
Keyword(s):  
Dissolved Oxygen ◽  
Extreme Event ◽  
Oxygen Depletion ◽  
Model Parameters ◽  
Combined Sewer Overflows ◽  
Quality Model ◽  
Combined Sewer ◽  
Model Mouse ◽  
Sewer Overflows ◽  
Runoff Model

A method for stochastic analysis of the effect of combined sewer overflows on the dissolved oxygen concentration in receiving rivers is developed. The method is based on repeated operation of the water quality model MOUSE-DOSMO. Each operation of this model covers a series of overflow events calculated by the MOUSE-SAMBA runoff model based on a historical rainfall record. For each event selected input data and model parameters in both models are drawn from fundamental statistical distributions by a simple Monte Carlo method. These data and parameters vary from event to event in each series. Each operation of the MOUSE-DOSMO model results in an extreme event statistics on dissolved oxygen minimum values -while repeated operation of the model yields extreme event percentiles by means of which a probability-based assessment of the model result may be performed.

A software-based sensor for combined sewer overflows

2012 ◽  
Vol 66 (7) ◽  
pp. 1475-1482 ◽  
Author(s):  
G. Leonhardt ◽  
S. Fach ◽  
C. Engelhard ◽  
H. Kinzel ◽  
W. Rauch
Keyword(s):  
Water Level ◽  
Simulation Models ◽  
Rainfall Runoff ◽  
Combined Sewer Overflows ◽  
Quality Model ◽  
Level Data ◽  
Water Level Data ◽  
Combined Sewer ◽  
Rainfall Runoff Model ◽  
Runoff Model

A new methodology for online estimation of excess flow from combined sewer overflow (CSO) structures based on simulation models is presented. If sufficient flow and water level data from the sewer system is available, no rainfall data are needed to run the model. An inverse rainfall-runoff model was developed to simulate net rainfall based on flow and water level data. Excess flow at all CSO structures in a catchment can then be simulated with a rainfall-runoff model. The method is applied to a case study and results show that the inverse rainfall-runoff model can be used instead of missing rain gauges. Online operation is ensured by software providing an interface to the SCADA-system of the operator and controlling the model. A water quality model could be included to simulate also pollutant concentrations in the excess flow.

Considering the impact of intermittent discharges when modelling overflows

1998 ◽  
Vol 38 (10) ◽  
pp. 23-30
Author(s):  
Sarah Jubb ◽  
Philip Hulme ◽  
Ian Guymer ◽  
John Martin
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Preliminary Investigation ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Combined Sewer Overflows ◽  
River Hydraulics ◽  
Combined Sewer ◽  
The Impact ◽  
Curve Equation

This paper describes a preliminary investigation that identified factors important in the prediction of river water quality, especially regarding dissolved oxygen (DO) concentration. Intermittent discharges from combined sewer overflows (CSOs) within the sewerage, and overflows at water reclamation works (WRW) cause dynamic conditions with respect to both river hydraulics and water quality. The impact of such discharges has been investigated under both wet and dry weather flow conditions. Data collected from the River Maun, UK, has shown that an immediate, transient oxygen demand exists downstream of an outfall during storm conditions. The presence of a delayed oxygen demand has also been identified. With regard to modelling, initial investigations used a simplified channel and the Streeter-Phelps (1925) dissolved oxygen sag curve equation. Later, a model taking into account hydrodynamic, transport and dispersion processes was used. This suggested that processes other than water phase degradation of organic matter significantly affect the dissolved oxygen concentration downstream of the location of an intermittent discharge. It is proposed that the dynamic rate of reaeration and the sediment oxygen demand should be the focus of further investigation.

scholarly journals Intensive monitoring of conventional and surrogate quality parameters in a highly urbanized river affected by multiple combined sewer overflows

2018 ◽  
Vol 19 (3) ◽  
pp. 953-966 ◽  
Author(s):  
D. Copetti ◽  
L. Marziali ◽  
G. Viviano ◽  
L. Valsecchi ◽  
L. Guzzella ◽  
...  
Keyword(s):  
Total Phosphorus ◽  
Laboratory Data ◽  
Quality Parameters ◽  
Nutrient Concentrations ◽  
Combined Sewer Overflows ◽  
Continuous Measurements ◽  
Combined Sewer ◽  
Early Peak ◽  
Sewer Overflows ◽  
The Impact

Abstract The paper reports results of four intensive campaigns carried out on the Seveso River (Milan metropolitan area, Italy) between 2014 and 2016, during intense precipitation events. Laboratory analyses were coupled with on-site, continuous measurements to assess the impact of pollutants on water quality based on both conventional and surrogate parameters. Laboratory data included total suspended solids, caffeine, total phosphorus and nitrogen, and their dissolved forms. Screening of trace metals (Cr, Cu, Pb, Ni, Cd) and PBDEs (polybromodiphenylethers) was carried out. Continuous measurements included water level, physico-chemical variables and turbidity. Nutrient concentrations were generally high (e.g. average total phosphorus > 1,000 μg/L) indicating strong sewage contributions. Among monitored pollutants Cr, Cu, Pb, and Cd concentrations were well correlated to TSS, turbidity and discharge, being bound mostly to suspended particulate matter. A different behavior was found for Ni, that showed an early peak occurring before the flow peak, as a result of first flush events. PBDEs correlated well to nutrient concentrations, showing the highest peaks soon after activation of the combined sewer overflows, likely because of its accumulation in sewers. In addition to showing the existing correlations between quality parameters, the paper highlights the importance of surrogate parameters as indicators of anthropic pollution inputs.

Emission-immission based design of combined sewer overflows and treatment plant - the dresden case study

1997 ◽  
Vol 36 (8-9) ◽  
pp. 355-359
Author(s):  
L. Fuchs ◽  
D. Gerighausen ◽  
S. Schneider
Keyword(s):  
Treatment Plant ◽  
Combined Sewer Overflows ◽  
Quality Model ◽  
Combined Sewer ◽  
Receiving Waters ◽  
Sewer Overflows ◽  
Set Up ◽  
The City

For the city of Dresden a general master plan was set up based on investigations of the hydraulic capacity of the sewer system, the loads from combined sewer overflow and the treatment plant. The total emission from combined sewer overflows and treatment plant was the main criteria for the analysis of the efficiency of different renovation alternatives. The effect of the different alternatives on the quality of the receiving waters was investigated with a water quality model and evaluated with different approaches.

Prédiction des débits de ruissellement pour le contrôle des réseaux d'égouts unitaires

1982 ◽  
Vol 9 (3) ◽  
pp. 537-548 ◽  
Author(s):  
Gilles Patry ◽  
Gilles Marchi ◽  
Jean Rousselle
Keyword(s):  
Regression Models ◽  
Urban Runoff ◽  
Point Sources ◽  
Combined Sewer Overflows ◽  
Water Users ◽  
Sources Of Pollution ◽  
Combined Sewer ◽  
Sewer Overflows ◽  
Overflow Control ◽  
Runoff Model

As point sources of pollution are being eliminated others, less apparent, are becoming increasingly threatening to many water users. Non-point sources of pollution generated by combined sewer overflows have been found to be responsible for many of our water quality problems. The purpose of this paper is twofold: (a) to offer a summary of the combined sewer overflow control problem, and (b) to suggest a methodology for the anticipation or prediction of runoff flows from an urban catchment.Two types of regression models designed to predict urban runoff are presented and compared with the calibrated runoff model ILLUDAS. The simplicity of regression models and their ease of application to the real-time automatic control of combined sewer overflows make their use very promising.

scholarly journals A Detention Reservoir Reduced Combined Sewer Overflows and Bathing Water Contamination Due to Intense Rainfall

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3425
Author(s):  
Marco Romei ◽  
Matteo Lucertini ◽  
Enrico Esposito Renzoni ◽  
Elisa Baldrighi ◽  
Federica Grilli ◽  
...  
Keyword(s):  
Environmental Concern ◽  
Treatment Options ◽  
Heavy Rain ◽  
Rain Event ◽  
Storm Events ◽  
Combined Sewer Overflows ◽  
Bathing Water ◽  
Combined Sewer ◽  
Sewer Overflows ◽  
The Impact

Combined sewer overflows (CSOs) close to water bodies are a cause of grave environmental concern. In the past few decades, major storm events have become increasingly common in some regions, and the meteorological scenarios predict a further increase in their frequency. Consequently, CSO control and treatment according to best practices, the adoption of innovative treatment solutions and careful sewer system management are urgently needed. A growing number of publications has been addressing the quality, quantity and types of available water management and treatment options. In this study, we describe the construction of an innovative detention reservoir along the Arzilla River (Fano, Italy) whose function is to store diluted CSO wastewater exceeding the capacity of a combined drain system. River water sampling and testing for microbial contamination downstream of the tank after a heavy rain event found a considerable reduction of fecal coliform concentrations, which would have compounded the impact of stormwater on the bathing site. These preliminary results suggest that the detention tank exerted beneficial environmental effects on bathing water by lowering the microbial load.

The feasibility of flocculation in a storage sedimentation basin

1999 ◽  
Vol 39 (2) ◽  
pp. 75-83 ◽  
Author(s):  
W. De Cock ◽  
P. Blom ◽  
G. Vaes ◽  
J. Berlamont
Keyword(s):  
Numerical Model ◽  
Velocity Gradient ◽  
Settling Velocity ◽  
Pollution Load ◽  
Combined Sewer Overflows ◽  
Combined Sewer ◽  
Efficiency Increase ◽  
Receiving Waters ◽  
Sedimentation Basins ◽  
The Impact

For the Flemish situation, storage sedimentation basins are one of the best ‘end-of-pipe’ solutions to reduce the impact of combined sewer overflows on the receiving waters. In some cases, when the spilled pollution load is too high, the settling efficiency of the basin has to be improved. Adding coagulants could be a reasonable alternative for building larger basins. To estimate the effect of enhancing the settling by flocculation, a floc growth and break-up model is worked out and is implemented in the numerical model Phoenics. The evolution of the floc dimensions and the sedimentation behaviour of the particles in the basin is calculated for different inflow rates and initial settling velocity profiles. Finally, the efficiency increase by mixing (creating a higher velocity gradient) in the agitation chamber or by adding coagulants in the trunk sewer upstream of the basin is also investigated.

scholarly journals Microplastics in Combined Sewer Overflows: An Experimental Study

2021 ◽  
Vol 9 (12) ◽  
pp. 1415
Author(s):  
Fabio Di Nunno ◽  
Francesco Granata ◽  
Francesco Parrino ◽  
Rudy Gargano ◽  
Giovanni de Marinis
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Water Bodies ◽  
Combined Sewer Overflows ◽  
Side Weir ◽  
Combined Sewer ◽  
Sewer Overflows ◽  
Water Outflow ◽  
The Impact

One of the main sources of microplastics inside surface waters is represented by combined sewer overflows (CSOs), involving severe risks for the environment. The entry of microplastics into water bodies also depends on the characteristics of sewer diversion structures used as flow control devices. In this work, an experimental investigation was carried out to evaluate the outflow of microplastic particles, consisting of different types of nylon fibers, from a side weir located on a channel with a rectangular section. A specific methodology was developed for the fiber sampling and outflow assessment after the tests were performed. For the tested configurations, an increase in fibers discharged up to 196.15% was measured as the water flow rate increased by 62.75%, combined with an increase in the side weir length up to 40% and a decrease in the crest height up to 20%. The size and weight of the different fibers showed a low impact due to their low inertia, and their motion was governed by the water flow. An empirical equation to evaluate the fiber outflow as a function of water flow rate and side weir geometric characteristics was also proposed and calibrated for the experimentally tested ranges of the dimensionless lateral water outflow Q* = 0.51–0.83 and of the dimensionless geometric parameter S* = 0.114–0.200. These first experimental results make it possible to carry out a preliminary assessment of the impact of CSOs in terms of microplastics spilled into water bodies.

scholarly journals Problems, Challenges, and Removing Methods of Micro Plastics from Water

2021 ◽  
Vol 9 (9) ◽  
pp. 941-946
Author(s):  
Dr. V. Venkata Lakshmi
Keyword(s):  
Drinking Water ◽  
Distribution Systems ◽  
Industrial Effluent ◽  
Combined Sewer Overflows ◽  
The Past ◽  
Untreated Wastewater ◽  
Run Off ◽  
Combined Sewer ◽  
The Impact ◽  
Health Process

Abstract: Over the past few years, several studies have reported the presence of micro plastics in treated tap and bottled water, raising questions and concerns about the impact that micro plastics in drinking-water might have on human health. Microplastics are ubiquitous within the environment and are detected in marine water, wastewater, water, food, air and drinking-water, both bottled and water. Microplastics enter freshwater environments in a number of ways: primarily from surface run-off and both treated and untreated wastewater effluent, but also from combined sewer overflows, industrial effluent degraded plastic waste and atmospheric deposition. Further, the limited evidence indicates that some microplastics found in drinking-water may come from treatment and distribution systems for water and/or bottling of drinking water. Keywords: Fresh water, health, process.

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