Modelling of sedimentation and remobilization in in-line storage sewers for stormwater treatment

2005 ◽  
Vol 52 (5) ◽  
pp. 151-158 ◽  
Author(s):  
T. Frehmann ◽  
C. Flores ◽  
F. Luekewille ◽  
T. Mietzel ◽  
B. Spengler ◽  
...  
Keyword(s):  
Pilot Plant ◽  
Combined Sewer Overflow ◽  
Stormwater Treatment ◽  
Sewer System ◽  
Plant Model ◽  
Empirical Modelling ◽  
Model Study ◽  
Combined Sewer ◽  
Pilot Plant Study ◽  
Special Arrangement

A special arrangement of combined sewer overflow tanks is the in-line storage sewer with downstream discharge (ISS-down). This layout has the advantage that, besides the sewer system, no other structures are required for stormwater treatment. The verification of the efficiency with respect to the processes of sedimentation and remobilization of sediment within the in-line storage sewer with downstream discharge is carried out in a combination of a field and a pilot plant study. The model study was carried out using a pilot plant model scaled 1:13. The following is intended to present some results of the pilot plant study and the mathematical empirical modelling of the sedimentation and remobilization process.

Monitoring in inline storage sewers for stormwater treatment to determine efficiencies

2004 ◽  
Vol 50 (11) ◽  
pp. 89-96
Author(s):  
T. Frehmann ◽  
T. Mietzel ◽  
R. Kutzner ◽  
B. Spengler ◽  
W.F. Geiger
Keyword(s):  
Water Samples ◽  
Monitoring Station ◽  
Total Efficiency ◽  
Combined Sewer Overflow ◽  
Stormwater Treatment ◽  
Erosion Process ◽  
Sewer System ◽  
Combined Sewer ◽  
Sewer Overflow ◽  
Reducing Costs

A special structure of combined sewer overflow tanks is the inline storage sewer with downstream discharge (SKU). This layout has the advantage that besides the sewer system, no other structures are required for storm water treatment. Consequently only very little space is required and compared to combined sewer overflow tanks, there is an enormous potential in reducing costs during construction. To investigate the efficiency of an inline storage sewer, a monitoring station was established in Dortmund-Scharnhorst, Germany. The monitoring station was in operation for a period of 2.5 years. Within this period water samples were taken during a total of 20 discharge events. Besides the complete hydraulic data collection, seven water samplers took more than 5,000 water samples during dry and wet weather. This adds up to a total of more than 20,000 individual lab analyses. The average of the total efficiency for the SKU-West is 86%. 29% of this efficiency can be attributed to the throttle flow. The remaining 57% can be divided into a part of 48% that can be attributed to the process storage and 9% that can be attributed to sedimentation and erosion process.

Combined sewer overflow over an oblique weir at Rat Creek in Edmonton, Alberta

2010 ◽  
Vol 37 (3) ◽  
pp. 477-488
Author(s):  
Elizabeth Valentine ◽  
Kurt Kronebusch ◽  
David Z. Zhu ◽  
N. Rajaratnam ◽  
Sid Lodewyk ◽  
...  
Keyword(s):  
Urban Drainage ◽  
Combined Sewer Overflow ◽  
Rating Curve ◽  
Flow Conditions ◽  
Sewer System ◽  
Sewer Systems ◽  
Model Study ◽  
Combined Sewer ◽  
Sewer Overflow

Oblique weirs are commonly used in urban drainage systems to remove excess flow from a sewer, in particular, a combined sewer system that has limited conveyance capacity. It is important to understand the hydraulics of these weirs to properly monitor the amount of the overflows as well as to design and improve sewer systems. The Rat Creek structure in Edmonton, Alberta, is a combined sewer overflow structure with a weir at an oblique alignment to the centerline of the sewer. A physical model study of the structure was conducted. The results show that both the approach flow conditions and the chamber geometry can significantly affect the hydraulic performance of the weir and invalidate the application of standard weir equations. A unique flow regime with a linear head–discharge rating curve was observed. The effects of modifying the weir and the hanging baffle wall downstream of the weir were also studied and reported. The results of this case study help to improve the understanding of the hydraulics of oblique weirs in 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.

Stormwater Treatment in Combined Sewer Systems in Germany

1992 ◽  
Vol 26 (7-8) ◽  
pp. 1841-1849
Author(s):  
R. Pecher
Keyword(s):  
Design Process ◽  
Stormwater Treatment ◽  
Sewer System ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Combined Sewer System

The use of stormwater detention tanks and their effect on combined sewer system are discussed. The design process is outlined, with particular attention to the most recent ATV guidelines.

Real Time Control in Part of Copenhagen

1993 ◽  
Vol 27 (12) ◽  
pp. 209-212 ◽  
Author(s):  
Jørgen Jens Linde-Jensen
Keyword(s):  
Real Time ◽  
Storage Capacity ◽  
Combined Sewer Overflow ◽  
Real Time Control ◽  
Sewer System ◽  
Time Control ◽  
Combined Sewer ◽  
Sewer Overflow

The application of real-time control to the sewer system in a district of Copenhagen is described. It enables the storage capacity of the sewer system to be better utilised, thus minimizing combined sewer overflow pollution.

DESIGN OF STORMWATER INFILTRATION FOR REDUCTION OF COMBINED SEWER OVERFLOW (CSO)

1994 ◽  
Vol 30 (1) ◽  
pp. 53-61 ◽  
Author(s):  
C. O. Rosted Petersen ◽  
P. Jacobsen ◽  
P. S. Mikkelsen
Keyword(s):  
Optimal Solution ◽  
Combined Sewer Overflow ◽  
Return Periods ◽  
Sewer System ◽  
Impervious Area ◽  
Combined Sewer ◽  
Sewer Overflow ◽  
Applied Design ◽  
Design Return Periods ◽  
Stormwater Infiltration

Stormwater infiltration is a significant tool for combined sewer overflow abatement because it involves a decrease in the impervious area connected to the sewer system. When allowing the infiltration structures to overflow into the existing sewer it is shown that for a required reduction in CSO-volume there exists an unambiguous relation between the infiltration structure volume and the size of impervious area connected to infiltration. Further, the presence of an optimal solution minimizing the total trench volume is pointed out. For a Danish sewer system with a travel time of 30 min and an interceptor capacity of 0.2 μm/s the optimal solution for reducing the CSO-volumes by 40 percent involves connecting 65 percent of the impervious area to infiltration trenches with a total storage volume of 3.6 mm. This corresponds to designing the trenches according to an exceedence return period of 0.04 yrs compared to the commonly applied design return periods of 2 to 10 yrs.

Comparison of conventional rule based flow control with control processes based on fuzzy logic in a combined sewer system

2002 ◽  
Vol 46 (6-7) ◽  
pp. 77-84 ◽  
Author(s):  
K. Klepiszewski ◽  
T.G. Schmitt
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Control ◽  
Flow Control ◽  
Control Systems ◽  
Combined Sewer Overflow ◽  
Sewer System ◽  
Rule Based ◽  
Combined Sewer ◽  
Combined Sewer System ◽  
Sewer Overflow

While conventional rule based, real time flow control of sewer systems is in common use, control systems based on fuzzy logic have been used only rarely, but successfully. The intention of this study is to compare a conventional rule based control of a combined sewer system with a fuzzy logic control by using hydrodynamic simulation. The objective of both control strategies is to reduce the combined sewer overflow volume by an optimization of the utilized storage capacities of four combined sewer overflow tanks. The control systems affect the outflow of four combined sewer overflow tanks depending on the water levels inside the structures. Both systems use an identical rule base. The developed control systems are tested and optimized for a single storm event which affects heterogeneously hydraulic load conditions and local discharge. Finally the efficiencies of the two different control systems are compared for two more storm events. The results indicate that the conventional rule based control and the fuzzy control similarly reach the objective of the control strategy. In spite of the higher expense to design the fuzzy control system its use provides no advantages in this case.

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.

Flow and pollutant measurements in a combined sewer system to operate a wastewater treatment plant and its storage tank during storm events

1995 ◽  
Vol 31 (7) ◽  
pp. 1-12 ◽  
Author(s):  
J.-L. Bertrand-Krajewski ◽  
M. Lefebvre ◽  
B. Lefai ◽  
J.-M. Audic
Keyword(s):  
Storage Tank ◽  
Treatment Plant ◽  
Integrated Approach ◽  
Stormwater Treatment ◽  
Storm Events ◽  
Sewer System ◽  
Combined Sewer ◽  
The Future ◽  
Combined Sewer System ◽  
Storm Drainage

Urban storm drainage is considered using an integrated approach taking into account all parts of the sewer system: pipes, storage tanks, overflows, treatment plant and receiving waters. This paper presents an experimental research in Boran-sur-Oise (France) where continuous measurements are carried out in the combined sewer system (catchment area 61 ha), in the storage tank (245 m3) and in the treatment plant (3000 p.e.). One of the objectives is a comprehensive knowledge of effects of storm events on treatment plant process and efficiency. Catchment, sewer system, storage tank, treatment plant and measurements are described. Results for an autumn rainfall are given as an example. Many impacts on the treatment plant are observed. Despite the load increase compared with dry weather periods, especially for TSS and ammonia, the plant efficiency remains satisfactory. Short-term and long-term impacts are distinguished. New rules for storage tank operation are proposed to avoid hydraulic plant overloading and to use the stormwater solids-settling properties. These rules will be tested in the future to verify their compatibility with receiving water quality requirements. Measurements in upstream sewer system could also be used in the future to operate stormwater treatment systems during storm events.

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