Model reduction through boundary relocation to facilitate real-time control optimisation in the integrated urban wastewater system

2002 ◽  
Vol 45 (4-5) ◽  
pp. 373-381 ◽  
Author(s):  
J. Meirlaen ◽  
P.A. Vanrolleghem
Keyword(s):  
Water Quality ◽  
Model Reduction ◽  
Real Time ◽  
Treatment Plant ◽  
Model Complexity ◽  
Urban Wastewater ◽  
Real Time Control ◽  
Sewer System ◽  
Time Control ◽  
The Impact

Real time control is one of the possibilities to minimise the impact of the integrated urban wastewater system (sewer system and treatment plant) on the receiving water quality. Integrated control uses information about the river state to act in the sewer system or in treatment plant. In order to test and tune these integrated controllers, a simplified integrated model is needed. Even with these simplified models, the simulation times may be too long and further model reduction is needed. In this paper, dependency-structure based model reduction is proposed as a technique to further reduce model complexity. Three steps are proposed: relocation of the upstream system boundaries to just upstream of the first control point, relocation of the downstream boundaries to just downstream of the last measurement point, and third, a further model simplification based on an analysis of the sensitivity of the control actions on submodel elimination. The effect of applying the different reduction approaches on the control strategy and on the resulting river water quality is discussed on the basis of a case study of the catchment of Tielt.

Optimisation and control of the inflow to a wastewater treatment plant using integrated modelling tools

1998 ◽  
Vol 37 (1) ◽  
pp. 347-354 ◽  
Author(s):  
Ole Mark ◽  
Claes Hernebring ◽  
Peter Magnusson
Keyword(s):  
Wastewater Treatment ◽  
Real Time ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Pilot Project ◽  
Integrated Modelling ◽  
Real Time Control ◽  
Sewer System ◽  
Time Control ◽  
The Impact

The present paper describes the Helsingborg Pilot Project, a part of the Technology Validation Project: “Integrated Wastewater” (TVP) under the EU Innovation Programme. The objective of the Helsingborg Pilot Project is to demonstrate implementation of integrated tools for the simulation of the sewer system and the wastewater treatment plant (WWTP), both in the analyses and the operational phases. The paper deals with the programme for investigating the impact of real time control (RTC) on the performance of the sewer system and wastewater treatment plant. As the project still is in a very early phase, this paper focuses on the modelling of the transport of pollutants and the evaluation of the effect on the sediment deposition pattern from the implementation of real time control in the sewer system.

Real time control of the integrated urban wastewater system using simultaneously simulating surrogate models

2002 ◽  
Vol 45 (3) ◽  
pp. 109-116 ◽  
Author(s):  
J. Meirlaen ◽  
J. Van Assel ◽  
P. A. Vanrolleghem
Keyword(s):  
Water Quality ◽  
Real Time ◽  
River Water ◽  
Control Strategy ◽  
Treatment Plant ◽  
River Water Quality ◽  
Urban Wastewater ◽  
Real Time Control ◽  
Time Control

The urban wastewater system (sewer and treatment plant) has a major impact on the river water quality of urban streams. To minimise this impact, real time control is a valuable option. Since the ultimate goal of any control strategy is to optimise the quality of the river system, it is useful to take pollutant immissions into account when determining the control strategy and/or the setpoints of the controller. However, a simultaneously simulating model of the complete system is needed in order to allow design and evaluation of such control strategies. In this work an integrated model of the urban wastewater system is created. This has been accomplished by implementing surrogate models of the three subsystems within a single software platform. The coupled submodels are subsequently used in a semi-hypothetical case study to optimise the resulting river water quality. An ammonia sensor in the river has been used to control the amount of water treated biologically in the treatment plant. It was shown that this integrated control could lower the peak ammonia concentration in the part of the river downstream of the treatment plant. Hence, a proof of principle has been given that the use of measurements in the river to perform control actions in the sewer system and the treatment plant is a promising option.

Effects of real time control of sewer systems on treatment plant performance and receiving water quality

2002 ◽  
Vol 45 (3) ◽  
pp. 229-237 ◽  
Author(s):  
T. Frehmann ◽  
A. Niemann ◽  
P. Ustohal ◽  
W.F. Geiger
Keyword(s):  
Real Time ◽  
Treatment Plant ◽  
Drainage System ◽  
Control Measures ◽  
Plant Performance ◽  
Integral Model ◽  
Real Time Control ◽  
Time Control ◽  
The Impact ◽  
Receiving Water

Four individual mathematical submodels simulating different subsystems of urban drainage were intercoupled to an integral model. The submodels (for surface runoff, flow in sewer system, wastewater treatment plant and receiving water) were calibrated on the basis of field data measured in an existing urban catchment investigation. Three different strategies for controlling the discharge in the sewer network were defined and implemented in the integral model. The impact of these control measures was quantified by representative immission state-parameters of the receiving water. The results reveal that the effect of a control measure may be ambivalent, depending on the referred component of a complex drainage system. Furthermore, it is demonstrated that the drainage system in the catchment investigation can be considerably optimised towards environmental protection and operation efficiency if an appropriate real time control on the integral scale is applied.

Astlingen – a benchmark for real time control (RTC)

2018 ◽  
Vol 2017 (2) ◽  
pp. 552-560 ◽  
Author(s):  
Manfred Schütze ◽  
Maja Lange ◽  
Michael Pabst ◽  
Ulrich Haas
Keyword(s):  
Real Time ◽  
Preliminary Analysis ◽  
Control Strategies ◽  
Treatment Plant ◽  
Drainage System ◽  
Real Time Control ◽  
Sewer System ◽  
Time Control ◽  
System 2 ◽  
Water Association

Abstract This contribution serves two purposes. (1) It presents an updated version of the Astlingen example developed by the working group ‘Integral Real Time Control’ of the German Water Association (DWA), which serves as a benchmark example for the setup and evaluation of real time control strategies. As this benchmark is also intended for educational use, it demonstrates a simple RTC algorithm, illustrating the main concepts of RTC of drainage system. (2) The paper also encourages the preliminary analysis of the potential feasibility and benefit of a temporal increase of inflow to the wastewater treatment plant (WWTP) before analysing the WWTP behaviour in detail. For the present example, RTC within the sewer system alone led to almost the same reduction of overflow volume as permitting the inflow to the WWTP to be increased for 6 h within any 24 h, if at all permitted.

Criteria for assessment of the operational potential of the urban wastewater system

2002 ◽  
Vol 45 (3) ◽  
pp. 141-148 ◽  
Author(s):  
M. Schütze ◽  
D. Butler ◽  
M.B. Beck ◽  
H.-R. Verworn
Keyword(s):  
Real Time ◽  
Case Studies ◽  
Simulation Study ◽  
General Procedure ◽  
Treatment Plant ◽  
Urban Wastewater ◽  
Real Time Control ◽  
Time Control ◽  
Individual Site ◽  
Quality Aspects

Application of real-time control (RTC) is one possible measure to increase the performance of the urban wastewater system. However, the potential and the benefits of control depend strongly on the characteristics of the individual site under question. Conventionally, to evaluate this potential, a detailed feasibility study had to be carried out. In some cases, such a study may well conclude that, for the given site, real-time control does not have any significant potential, thus resulting in unnecessarily having spent precious resources for a detailed study. It would be desirable to have a methodology that allows simple, and cost-effective, screening of sites for which the analysis of real-time control may be beneficial. Earlier research led to the provision of an easy-to-apply scoring system which allows a quick assessment of the RTC potential of controlling flow in sewer systems. However, since this procedure does not take into account water quality aspects, or the treatment plant or the receiving water body, it cannot be used for assessing the potential of RTC of the complete system, let alone for integrated RTC. This paper describes the first part of an on-going project which aims at establishing an enhanced procedure for assessing the real-time control potential for the entire urban wastewater system. After providing a definition of the term “RTC potential”, a large number of (partly hypothetical) case studies (varying a number of key parameters of the wastewater system) is simulated, using the simulation tool SYNOPSIS. For each of these sites, a number of real-time control algorithms are developed and optimised, following a general procedure, which allows for local, global and integrated scenarios to be considered. Analysis of the results reveals those system parameters which are of particular significance to the RTC potential of urban wastewater systems. These are discussed and assessed in this paper. Furthermore, the results of a simulation study are provided which indicate a clear potential of integrated control even for many case studies for which local control provides hardly any benefits. Subsequent studies will complement the simulation study by comparison with a number of real case studies in various countries.

Interaction between the treatment plant and the sewer system in Halmstad: integrated upgrading based on real time control

1998 ◽  
Vol 37 (9) ◽  
pp. 127-134
Author(s):  
C. Hernebring ◽  
L. Ohlsson ◽  
M. Andreasson ◽  
L.-G. Gustafsson
Keyword(s):  
Wastewater Treatment ◽  
Real Time ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Rehabilitation Program ◽  
Real Time Control ◽  
Sewer System ◽  
Time Control ◽  
Flow Control Devices ◽  
Effective Use

In Halmstad, Sweden great efforts have been made during the 1990's to improve the functionality and to reduce the environmental impact of the sewer system and the wastewater treatment plant. The investment and rehabilitation program includes to a great extent an effective use of existing resources. The wastewater treatment plant is reconstructed to meet increased nutrient removal demands. A five year rehabilitation plan for the sewer system is under completion, where the measures mainly are motivated by the aim to reduce the combined sewer overflow volumes and to minimize the risk of local flooding. It was soon realized that an integrated use of storage volumes at the wastewater treatment plant and within the sewer system could improve the general conditions for the treatment at the plant. To implement this strategy a real time control system was introduced by installing controllable weirs and flow control devices in the main sewer. The article describes the background of the sewerage master plan, how the upgrading work has been carried out by means of simulations and measurement, gives examples of some expected potential benefits, and outlines plans for the future.

A methodology for assessing the operational potential of the urban wastewater system using integrated modelling

2003 ◽  
Vol 3 (1-2) ◽  
pp. 271-277 ◽  
Author(s):  
A.I. Zacharof ◽  
M. Schütze ◽  
D. Butler
Keyword(s):  
Real Time ◽  
Feasibility Study ◽  
General Procedure ◽  
Treatment Plant ◽  
Integrated Modelling ◽  
Urban Wastewater ◽  
Real Time Control ◽  
Time Control ◽  
Individual Site ◽  
Quality Aspects

Application of real-time control (RTC) is one possible measure to increase the performance of the urban wastewater system. However, the potential and the benefits of control depend strongly on the characteristics of the individual site under question. Conventionally, RTC potential is evaluated by performing a detailed feasibility study, which in some cases may conclude that for the given site real-time control does not have any significant potential. This can result in spending considerable precious resources for a detailed feasibility study only to identify the non-feasibility of RTC in the system. It would therefore be desirable to have a methodology that allows simple, and cost-effective, screening of sites for which the analysis of real-time control may be beneficial. Earlier research has led to the provision of an easy-to-apply scoring system allowing a quick assessment of the RTC potential of controlling flow in sewer systems. However, as this procedure does not take into account water quality aspects, nor the treatment plant or the receiving water body, it cannot be used for assessing the potential of RTC of the complete system. This paper describes the work of an on-going project aimed at establishing an enhanced procedure for assessing the real-time control potential for the entire urban wastewater system. This entails simulating many (partly hypothetical) case studies (varying several key parameters of the wastewater system) using the simulation tool SYNOPSIS. For each of these sites, several real-time control algorithms are developed and optimised, following a general procedure, which allows for local, global and integrated scenarios to be considered. Analysis of the results reveals those system parameters which are of particular significance to the RTC potential of urban wastewater systems. Furthermore, it is recognised that there is considerable uncertainty associated with modelling of such a large and diverse system and a framework is developed for incorporating this in the RTC potential screening tool. Finally, further work is currently underway in broadening the number of case study simulations and developing more complex approaches to quantifying and propagating uncertainty in the model.

Advanced real time control of a combined sewer system

1998 ◽  
Vol 37 (1) ◽  
pp. 319-326 ◽  
Author(s):  
Andreas Petruck ◽  
Andreas Cassar ◽  
Joachim Dettmar
Keyword(s):  
Water Quality ◽  
Real Time ◽  
Real Time Control ◽  
Sewer System ◽  
Time Control ◽  
Combined Sewer ◽  
Combined Sewer System ◽  
Complex Monitoring ◽  
Set Up

The research project ‘Real Time Control of a Combined Sewer System by Radar estimates of Precipitation’ seeks to improve the water quality of a stream by reducing quantitative and qualitative discharges of combined sewage overflow (CSO). The complex monitoring and simulation system that has been set up for control purposes is described. Two advanced real time control (ARTC) strategies have been developed. First a pollution based real time control (PBRTC) strategy, and second a water quality based real time control (WQBRTC) strategy. The PBRTC strategy is already implemented, the WQBRTC strategy will be implemented during the course of the project. For the PBRTC an off-line analysis is presented to show the effectiveness of the strategy.

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