Prediction of locations with sediment deposits in sewers

1996 ◽  
Vol 33 (9) ◽  
pp. 147-154 ◽  
Author(s):  
Ole Mark ◽  
Uros Cerar ◽  
Gustavo Perrusquía
Keyword(s):  
Sediment Transport ◽  
Field Data ◽  
Transport Model ◽  
Combined Sewer Overflows ◽  
Sewer System ◽  
Sewer Systems ◽  
Sediment Transport Model ◽  
Sediment Deposits ◽  
Combined Sewer ◽  
Movable Bed

The present paper presents an application of MOUSE ST, a general deterministic sediment transport model for sewer systems. MOUSE ST is used to predict the locations subjected to sedimentation in the sewer system of Ljubljana, Slovenia. The prediction is made by means of a sediment transport model with a movable bed. This model is run in parallel with the hydrodynamic MOUSE model. The results, in terms of locations with sediment deposits, are compared with field data from the sewer system in Ljubljana. Further, the model is used to predict the effect of the removal of the sediment deposits on the combined sewer overflows.

Sediment transport under dry weather conditions in a small sewer system

1998 ◽  
Vol 37 (1) ◽  
pp. 155-162
Author(s):  
Flemming Schlütter ◽  
Kjeld Schaarup-Jensen
Keyword(s):  
Sediment Transport ◽  
Field Data ◽  
Field Measurements ◽  
Weather Conditions ◽  
Sewer System ◽  
Transport Models ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Initial Results

Increased knowledge of the processes which govern the transport of solids in sewers is necessary in order to develop more reliable and applicable sediment transport models for sewer systems. Proper validation of these are essential. For that purpose thorough field measurements are imperative. This paper renders initial results obtained in an ongoing case study of a Danish combined sewer system in Frejlev, a small town southwest of Aalborg, Denmark. Field data are presented concerning estimation of the sediment transport during dry weather. Finally, considerations on how to approach numerical modelling is made based on numerical simulations using MOUSE TRAP (DHI 1993).

A Sediment Transport Model for Sewers

1992 ◽  
Vol 25 (8) ◽  
pp. 141-149
Author(s):  
O. Mark
Keyword(s):  
Sediment Transport ◽  
Transport Model ◽  
Hydrodynamic Description ◽  
Sewer Systems ◽  
Sediment Transport Model ◽  
Sediment Deposits ◽  
Bed Forms ◽  
Morphological Model ◽  
Technical University ◽  
The University

This paper describes a mathematical sediment transport model for sewers. The model consists of a full hydrodynamic description running in parallel with a morphological model. Four different sediment transport formulations have been implemented in the model. Fredsøe's method for the calculation of the resistance from bed forms is compared to experiments carried out at Chalmers Technical University, Sweden. The model can be used as a tool for the analysis of sewer systems with sediment deposits. The model is being developed as part of a study being carried out at the University of Aalborg, Denmark and VBB-VIAK, Sweden.

Washoff behavior of in-sewer deposit in combined sewer system through artificial flushing experiment

2010 ◽  
Vol 61 (11) ◽  
pp. 2835-2842 ◽  
Author(s):  
W. J. Kim ◽  
S. Managaki ◽  
H. Furumai ◽  
F. Nakajima
Keyword(s):  
Time Series ◽  
Flow Rate ◽  
Enteric Viruses ◽  
Pathogenic Microorganisms ◽  
Combined Sewer Overflows ◽  
Sewer System ◽  
Bacterial Indicators ◽  
Sewer Systems ◽  
Combined Sewer

In-sewer deposits in combined sewer systems (CSSs) are closely related with the behavior of first foul flush and combined sewer overflows. However, the research paying attention to the role of in-sewer deposits is quite rare, furthermore, their contributions for the washoff patterns of each pollutant including pathogenic microorganisms are almost never discussed so far. The artificial flushing experiment separating the washoff of in-sewer deposits from the inflow of surface pollutants was carried out to simulate the first foul flush in a CSS. The washoff behaviors of each pollutant including bacterial indicators and enteric viruses were investigated. Several morphological analyses for the concentration and load curves of each parameter were conducted and all patterns were classified according to their washoff characteristics and first foul flush patterns. The washoff behaviors of each pollutant and microorganism are different from each other and categorized into several groups according to their (i) time-series concentration and load curves and (ii) concentration vs. flow rate curves, respectively. The first foul flush patterns of each parameter were to be categorized into typical 3 groups; strong-, partial-, and no first foul flush group. The order of these groups signifies the strength of the first foul flush phenomena and the runoff priority as well.

Development of a Guideline for Sewer Operation and Maintenance in Austria

2007 ◽  
Vol 2 (1) ◽  
Author(s):  
A.N.A. Schellart ◽  
S.J. Tait ◽  
R.M. Ashley ◽  
C. Howes ◽  
M. McLoughlin
Keyword(s):  
Field Data ◽  
Management Strategies ◽  
Sediment Management ◽  
Management Options ◽  
Sewer System ◽  
Operation And Maintenance ◽  
Sediment Deposits ◽  
Combined Sewer ◽  
Potential Impact ◽  
Operational Activities

This paper reports on an investigation that aimed to develop appropriate sediment management strategies for a small combined sewer network. Field data from a 2-year field study were used to illustrate the potential impacts of various strategies. The fieldwork collected data on the potential impact of persistent sediment deposits found in a large combined sewer in London. The data collected was used to support modelling of the hydraulic and the sediment behaviour in the local sewer system. The model results were used to investigate whether or not the sediment deposits found in sections of the main sewer would influence levels of surcharge and so impact on the risk of sewer flooding in the future. After it was established that sediment deposits in the main sewer could, under certain circumstances, change pipe surcharge levels, several sediment management options were examined in order to find the most suitable option. All options comprised additional planned operational activities combined with increased levels of infrastructure expenditure.

Field campaign on sediment transport behaviour in a pressure main from pumping station to wastewater treatment plant in Berlin

2017 ◽  
Vol 75 (9) ◽  
pp. 2025-2033
Author(s):  
M. Gunkel ◽  
E. Pawlowsky-Reusing
Keyword(s):  
Wastewater Treatment ◽  
Sediment Transport ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Weather Conditions ◽  
Sewer System ◽  
Field Campaign ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Transport Behaviour

As part of the project KURAS, the Berliner Wasserbetriebe realized a field campaign in 2015 in order to increase the process knowledge regarding the behaviour of transported sediment in the pressure main leading from the pumpstation to the wastewater treatment plant. The field campaign was conducted because of a lack of knowledge about the general condition of the pressure main due to its bad accessibility and the suspicion of deposits caused by hydraulic underload. The practical evidence of the sediment transport performance of this part of the sewer system, dependent on different load cases, should present a basis for further analysis, for example regarding flushing measures. A positive side-effect of the investigation was the description of the amount of pollutants caused by different weather conditions in combined sewer systems and the alterations of the sewage composition due to biogenic processes during transport. The concept included the parallel sampling of the inflow at the pumpstation and the outflow at the end of the pressure main during different weather conditions. By calculating the inflow to the pressure main, as well as its outflow at different flow conditions, it was possible to draw conclusions in regard to the transport behaviour of sediment and the bioprocesses within an 8.5 km section of the pressure main. The results show clearly that the effects of sedimentation and remobilization depend on the flow conditions. The balance of the total suspended solids (TSS) load during daily variations in dry weather shows that the remobilization effect during the run-off peak is not able to compensate for the period of sedimentation happening during the low flow at night. Based on the data for dry weather, an average of 238 kg of TSS deposits in the pressure main remains per day. The remobilization of sediment occurs only due to the abruptly increased delivery rates caused by precipitation events. These high pollution loads lead to a sudden strain at the wastewater treatment plant. It was found that the sediment transport behaviour is characterized by sedimentation up to a flow velocity of 0.35 m/s, while remobilization effects occur above 0.5 m/s. The assumption of bad sediment transport performance in the pressure main was confirmed. Therefore, the results can be used as a basis for further analysis, for example regarding periodical flushing as a means of cleaning the pressure main. The findings, especially regarding the methods and processes, are transferable and can be applied to other pressure mains in combined sewer systems. Besides the outlined evaluation of the sediment transport behaviour of the pressure main, the collected data were used in the project to calibrate a sewer system model, including a water quality model for the catchment area, and as a contribution towards an early physically based sediment transport modelling in InfoWorks CS.

scholarly journals SEDIMENT TRANSPORT FIELD DATA AND NUMERICAL MODELING STUDY TO SUPPORT DREDGE PIT INFILL RATE ESTIMATES

2020 ◽  
pp. 57
Author(s):  
Atilla Bayram ◽  
Sean O'Neil ◽  
Yang Zhang
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Field Data ◽  
Transport Model ◽  
Phase 1 ◽  
Field Measurements ◽  
Suspended Load ◽  
Suspended Sediment Transport ◽  
Sediment Transport Model ◽  
Project Site

Site specific bedload and suspended sediment transport data collected at two test pit locations over a four-day period during April 2015 were analyzed to calibrate a numerical sediment transport model of Cook Inlet, AK. The field data campaign was designed to collect suspended load and bedload field measurements and was carried out in two phases. During Phase 1, both suspended load and bedload measurements were taken at approximately 55 ft water depth. The suspended sediment concentration was observed to be nearly uniform over the water column. Laboratory analysis showed the suspended sediment had an effective grain size of approximately 0.03 mm with 0.005 mm within a 95percent confidence interval. During Phase 2, hydrodynamic, suspended load and bedload measurements were collected over four tidal cycles in the surfzone. A two-dimensional sediment transport model was developed to simulate sediment transport infill rates at the dredged areas of the Project site. The model was calibrated by comparing measured suspended load measurements made at two offshore locations. Calibration results showed that the suspended load transport rate, which is the dominant sediment transport regime in the area, can be predicted accurately at the project site. Based on the calibrated sediment transport model, preliminary annual sediment infill rates were estimated to lie between 1.1 to 1.6 ft/yr at offshore and nearshore locations, respectively, for the presently observed and measured conditions.

A conceptual model for sediment transport in combined sewer systems

1999 ◽  
Vol 39 (9) ◽  
pp. 39-46 ◽  
Author(s):  
Flemming Schlütter
Keyword(s):  
Sensitivity Analysis ◽  
Sediment Transport ◽  
Conceptual Model ◽  
Qualitative Information ◽  
Sewer System ◽  
Erosion And Deposition ◽  
Sewer Systems ◽  
Hydraulic Conditions ◽  
Combined Sewer

This paper presents a numerical model capable of simulating sediment transport in combined sewer systems. The main objectives of the model are to model mass transport rates at the outlet from a catchment and at the same time obtaining qualitative information on erosion and deposition going on at different locations in the sewer system. The model is conceptual but based on deterministic computations of hydraulic conditions. The formulations used in the conceptual model (STSim) are presented as well as results from a sensitivity analysis. Finally, an example is given of a calibration event from a case study.

Urban Storm Water Discharges: Effects upon Communities of Sessile Diatoms and Macro-Invertebrates

1990 ◽  
Vol 22 (10-11) ◽  
pp. 147-154 ◽  
Author(s):  
G. D. Willemsen ◽  
H. F. Gast ◽  
R. O. G. Franken ◽  
J. G. M. Cuppen
Keyword(s):  
Organic Pollution ◽  
Constant Flow ◽  
Combined Sewer Overflows ◽  
Sewer System ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Receiving Waters ◽  
Sewer Overflows ◽  
Urban Storm

From 1985 to 1987, long-term and more or less permanent effects of discharges from combined or separate sewer systems on communities of sessile diatoms and macro-invertebrates in receiving waters have been studied. Sessile diatoms and/or macro-invertebrates have been investigated on 46 locations, spread all over The Netherlands. The results were related to the type of sewer system, the discharges, and the characteristics of the receiving water, and compared with results from sample(s) taken from a corresponding water not influenced by sewer overflows, the reference water. In general, communities of sessile diatoms and macro-invertebrates indicate a more severe organic pollution and disturbance of receiving waters compared with reference waters. In the immediate vicinity of the overflows these communities were more disturbed than at some distance. In small ditches, effects were more pronounced compared with large waterbodies and waters with a constant flow regime. Finally, effects of combined sewer overflows were more pronounced than effects of discharges from separate sewer systems, except for locations in industrial areas.

Principles and approaches for numerical modelling of sediment transport in sewers

1995 ◽  
Vol 31 (7) ◽  
pp. 107-115 ◽  
Author(s):  
Ole Mark ◽  
Cecilia Appelgren ◽  
Torben Larsen
Keyword(s):  
Mathematical Model ◽  
Sediment Transport ◽  
Numerical Modelling ◽  
Simple Application ◽  
Sewer Systems ◽  
Sediment Deposits ◽  
Model Mouse ◽  
Modelling Approaches

A study has been carried out with the objectives of describing the effect of sediment deposits on the hydraulic capacity of sewer systems and to investigate the sediment transport in sewer systems. A result of the study is a mathematical model MOUSE ST which describes sediment transport in sewers. This paper discusses the applicability and the limitations of various modelling approaches and sediment transport formulations in MOUSE ST. Further, the paper presents a simple application of MOUSE ST to the Rya catchment in Gothenburg, Sweden.

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