Is flow control in a space-constrained drainage network effective? A performance assessment for combined sewer overflow reduction

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.

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Foreword: Stormwater Management and Abatement of Combined Sewer Overflow Pollution

Water Quality Research Journal ◽

10.2166/wqrj.1997.001 ◽

1997 ◽

Vol 32 (1) ◽

pp. 1-228 ◽

Cited By ~ 10

Author(s):

J. Marsalek ◽

S. Kok

Keyword(s):

Stormwater Management ◽

Combined Sewer Overflow ◽

Combined Sewer ◽

Sewer Overflow

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Experience with Vortex Separators for Combined Sewer Overflow Control

Water Science & Technology ◽

10.2166/wst.1993.0489 ◽

1993 ◽

Vol 27 (5-6) ◽

pp. 93-104 ◽

Cited By ~ 6

Author(s):

H. Brombach ◽

C. Xanthopoulos ◽

H. H. Hahn ◽

W. C. Pisano

Keyword(s):

Separation Efficiency ◽

Operational Reliability ◽

Second Phase ◽

Combined Sewer Overflow ◽

Specific Storage ◽

Impervious Area ◽

Evaluation Phase ◽

Combined Sewer ◽

Sewer Overflow ◽

Overflow Control

In 1987 the first vortex solids separator facility in Germany was installed for combined sewer overflow (CSO) control. The separation efficiency was optimized in the hydraulic laboratory using scaled down models with artificial tracers to simulate typical sewage particulates. The station has two parallel operating vortex separators and serves a connected and impervious area of about 11 hectares (ha) and 1,500 people. The specific storage volume of the station is 7.2 m3 per ha. Two evaluation programs were conducted. The first evaluation phase noted the operational reliability, hydraulic loads, overflow frequencies and water mass balances. The second phase monitored separation efficiencies. The evaluation showed that vortex solids separators are now ready for use in CSO control.

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