Experimental and computational study of velocity fields in narrow or compound section sewers

2007 ◽  
Vol 2 (2) ◽  
Author(s):  
H. Bonakdari ◽  
F. Larrarte ◽  
J.-B. Bardiaux
Keyword(s):  
Cross Section ◽  
Computational Study ◽  
Velocity Fields ◽  
Combined Sewer Overflows ◽  
Flow Rates ◽  
Combined Sewer ◽  
Receiving Waters ◽  
Sound Management ◽  
Compound Section ◽  
Sewer Networks

Sound management of sewer networks and minimization of the pollution discharged into receiving waters through combined sewer overflows need in-depth knowledge of the flow rates and pollutant loads conveyed in sewers. This knowledge relies on a good assessment of the spatial distribution of the velocities in a cross section, as they are involved both in flowrate, and distribution of concentration. The possibility of assessing this distribution by using computational fluid dynamics is explored and compared with experimental results collected from real sewers.

Review of Rainfall Data Application for Design and Analysis

1984 ◽  
Vol 16 (8-9) ◽  
pp. 1-45 ◽  
Author(s):  
V Arnell ◽  
P Harremoës ◽  
M Jensen ◽  
N B Johansen ◽  
J Niemczynowicz
Keyword(s):  
Statistical Prediction ◽  
Dynamic Flow ◽  
Combined Sewer Overflows ◽  
Statistical Characterization ◽  
Data Application ◽  
Combined Sewer ◽  
Dynamic Flow Model ◽  
Receiving Waters ◽  
Rain Fall

This review has been prepared for the international seminar: Rain fall as the basis for urban runoff design and analysis, held in Copenhagen, 24'26 Aug. 1983. The purpose of the review is to bring a state of the art within, 1) the statistical characterization of rain fall in time and space, 2) the development of synthetic design storms and, 3) the application of both synthetic design storms and historical storms to pipe design, flooding prediction, design of detention basins and calculation of the yearly or extreme pollutiona1 load on receiving waters from combined sewer overflows. The main conclusion, primarily related to item 3), is that more attention in this context should be put on statistical analysis of the detrimental effects: flooding and pollution. This analysis is best performed by applying historical rain records. Realistic flooding prediction is believed only to be possible with a fully dynamic flow model, whereas pollution may be studied by means of simpler models like the time area approach. The outstanding problem in the statistical prediction is the distribution in space of the historical rains.

The influence of biodegradability of sewer solids for the management of CSOs

2005 ◽  
Vol 51 (2) ◽  
pp. 89-97 ◽  
Author(s):  
R. Sakrabani ◽  
R.M. Ashley ◽  
J. Vollertsen
Keyword(s):  
Weather Conditions ◽  
Bulk Water ◽  
Combined Sewer Overflows ◽  
Sediment Erosion ◽  
Combined Sewer ◽  
Utilisation Rate ◽  
Laboratory Device ◽  
Receiving Waters ◽  
Oxygen Utilisation ◽  
Wet Weather

The re-suspension of sediments in combined sewers and the associated pollutants into the bulk water during wet weather flows can cause pollutants to be carried further downstream to receiving waters or discharged via Combined Sewer Overflows (CSO). A typical pollutograph shows the trend of released bulk pollutants with time but does not consider information on the biodegradability of these pollutants. A new prediction methodology based on Oxygen Utilisation Rate (respirometric method) and Erosionmeter (laboratory device replicating in-sewer erosion) experiments is proposed which is able to predict the trends in biodegradability during in-sewer sediment erosion in wet weather conditions. The proposed new prediction methodology is also based on COD fractionation techniques.

Occurrence and fate of organic pollutants in combined sewer systems and possible impacts on receiving waters

2007 ◽  
Vol 56 (10) ◽  
pp. 141-148 ◽  
Author(s):  
A. Welker
Keyword(s):  
Organic Pollutants ◽  
Wastewater Treatment Plants ◽  
Combined Sewer Overflows ◽  
Sewer Systems ◽  
Flow Surface ◽  
Combined Sewer ◽  
Polycyclic Aromatic ◽  
Receiving Waters ◽  
First Time ◽  
Receiving Water

Selected organic pollutants are classified based on an intensive literature survey. Two wastewater parameters (COD and ammonium) and six selected organic pollutants (polycyclic aromatic hydrocarbons (PAH), diethylhexylphthalate (DEHP), estradiol (E2), ethinylestradiol (EE2), ethylenediamine tetraacetic acid (EDTA) and nitrilo triaceticacid (NTA)) are specified. As a result, for the first time representative concentrations in dry weather flow, surface runoff and effluent of wastewater treatment plants (WWTPs) in combined sewer systems (CSS) are stated. The second part of the paper presents a first estimation of main emission out of a combined sewer system and possible receiving water impacts in terms of (1) annual discharged loads calculated by pollution load simulations in a hypothetical catchment and (2) concentrations calculated in combined sewer overflows (CSO) discharges and resulting receiving water concentrations.

scholarly journals The importance of pollutional loads during wet weather

2019 ◽  
pp. 271-282
Author(s):  
Oddvar Georg Lindholm ◽  
Lars Aaby
Keyword(s):  
Time Series ◽  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
The Other ◽  
Combined Sewer Overflows ◽  
Combined Sewer ◽  
Receiving Waters ◽  
Wet Weather ◽  
Annual Discharge

Wet weather discharges consist mainly of washed out surface pollution in separate sewered areas, but in combined sewered areas; resuspended pipe deposits, surface washoff and sewage, discharging via combined sewer overflows (CSOs). Of the three mentioned sources, resuspended pipe solids is dominating over the other two and may contribute as much as 50 to 90 % of the total amount of the CSO. The CSO in a normal catchment may also on an annual bases be of the same amount, or even twice as much as the effluent from the wastewater treatment plant (WWTP). If the receiving waters are vulnerable to shock loads on a daily base, it is important to be aware that the amount of CSO might, at its most adverse be up to I 00 times more than the effluent from the WWTP during a day. The annual discharge via CSOs in a catchment may easily vary with a factor of up to 8 from the driest to the wettest year, during time series of 20 to 40 years.

scholarly journals Ecological aspect in combined sewer overflows chamber design

2013 ◽  
Vol 8 (3-4) ◽  
pp. 409-416
Author(s):  
J. Pollert
Keyword(s):  
Ecological Engineering ◽  
Combined Sewer Overflows ◽  
Reinforced Plastic ◽  
Combined Sewer ◽  
New Type ◽  
Receiving Waters ◽  
Sewer Overflows ◽  
The Cost ◽  
Floating Objects ◽  
Receiving Water

In 2005 one of major Czech manufacturers of glass reinforced plastic pipes asked the Department of Sanitary and Ecological Engineering to develop a new type of combined sewer overflows (CSO) chamber that could become a part of their manufacturing programme. The main requirements were economy of production, easy and fast installation on the field and increased protection of receiving waters. A simple object consisting of a pipe placed above another one was designed. The object begins with a stilling chamber formed by a conical expansion of the inlet pipe. It is separated from the overflow object itself by a downflow baffle designed to trap floating objects. The CSO chamber is equipped by a flow regulation device (e.g. vortex valve or throttle pipe) at the end. Excess water flows through a slit in the top of the bottom pipe into the upper pipe and from there to the receiving water. More than 15 prototypes were already installed in the Czech and Slovak Republics and more than 20 are planned to be built in Europe. We hope this type of CSO CHAMBER will help to decrease the cost of construction of new sewers and reconstruction of old ones. Its higher efficiency of separation of suspended particles might also contribute to the improvement of the quality of receiving water bodies according to Water Framework Directive 2000/60/EC.

Hydrodynamic Water Quality Simulation - An Approximative Solution

1991 ◽  
Vol 24 (6) ◽  
pp. 157-163
Author(s):  
E. Ristenpart ◽  
D. Wittenberg
Keyword(s):  
Water Quality ◽  
Drainage System ◽  
Urban Drainage ◽  
Flow Conditions ◽  
Nonstationary Flow ◽  
Combined Sewer Overflows ◽  
Water Quality Simulation ◽  
Combined Sewer ◽  
Receiving Waters ◽  
The One

Impacts from combined sewer systems on receiving waters are heavily polluting a lot of small river ecosystems. A simulation model which can be used to predict the development of water quality after combined sewer overflows and other impacts from the urban drainage system has been developed. This model works with hydrodynamic flow calculation because it is applied in a system of small wetland creeks with nonstationary flow conditions. The numerical solution of the differential equations is described as well as calibration results. It is shown that water quality simulation based on the one-dimensional mass transport equation is possible for nonstationary flow conditions and is going to become very useful in urban drainage planning.

Quantifying the inherent uncertainty in the quantity and quality of domestic wastewater

1996 ◽  
Vol 33 (2) ◽  
pp. 65-78 ◽  
Author(s):  
Eran Friedler ◽  
David Butler
Keyword(s):  
Domestic Wastewater ◽  
Combined Sewer Overflows ◽  
Pollutant Load ◽  
Fundamental Level ◽  
Frequency Of Use ◽  
Combined Sewer ◽  
Receiving Waters ◽  
Sewer Overflows ◽  
Domestic Appliances

Results from two surveys in S.E. England are used to illustrate and quantify the inherent uncertainty in the quantity and quality of domestic wastewater at the fundamental level of discharges from domestic appliances. The uncertainties in three principal areas are elucidated. Volumetric discharges are shown to vary significantly for several appliances particularly when used in “running to waste” mode. Pollutant load also varies and information is presented for a number of different appliance-pollutant combinations. The frequency of use is known to vary throughout the day, but figures are presented to quantify the extent of the spread of the data during each hour of the day. A means of integrating the various elements of uncertainty is proposed. Quantification should enable better control of treatment plants and improve forecasting of the influence of combined sewer overflows on receiving waters, hence enhancing the management of the associated risk.

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.

scholarly journals Application of integral pumping tests to investigate the influence of a losing stream on groundwater quality

2009 ◽  
Vol 6 (3) ◽  
pp. 4209-4232 ◽  
Author(s):  
S. Leschik ◽  
A. Musolff ◽  
R. Krieg ◽  
M. Martienssen ◽  
M. Bayer-Raich ◽  
...  
Keyword(s):  
Groundwater Quality ◽  
Treatment Plant ◽  
Test Site ◽  
Water Volume ◽  
Combined Sewer Overflows ◽  
Pumping Tests ◽  
Flow Rates ◽  
Combined Sewer ◽  
Mass Flow Rates ◽  
Integral Pumping Tests

Abstract. Losing streams that are influenced by wastewater treatment plant effluents and combined sewer overflows (CSO's) can be a source of groundwater contamination. Released micropollutants such as pharmaceuticals, endocrine disrupters and other ecotoxicologically relevant substances as well as inorganic wastewater constituents can reach the groundwater, where they may deteriorate groundwater quality. This paper presents a method to quantify exfiltration mass flow rates Mex of wastewater constituents from losing streams by the operation of integral pumping tests (IPT's) up- and downstream of a target section. Due to the large sampled water volume during IPT's the results are more reliable than those from conventional point sampling. We applied the method at a test site in Leipzig (Germany). Wastewater constituents K+ and NO3− showed Mex values of 1241 to 4315 and 749 to 924 mg m−1stream d−1, respectively, while Cl− (16.8 to 47.3 g m−1stream d−1) and SO42− (20.3 to 32.2 g m−1stream d−1) revealed the highest observed Mex values at the test site. The micropollutants caffeine and technical-nonylphenol were dominated by elimination processes in the groundwater between upstream and downstream wells. Additional concentration measurements in the stream and a connected sewer at the test site were performed to identify relevant processes that influence the concentrations at the IPT wells.

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