Real time control of urban wastewater systems—where do we stand today?

Manfred Schütze, Alberto Campisano, Hubert Colas, Wolfgang Schilling, Peter A. Vanrolleghem
2004 Journal of Hydrology  
This paper presents a review of the current state of the art of real time control (RTC) of urban wastewater systems. Control options not only of the sewer system, but also of the wastewater treatment plant and of receiving water bodies are considered. One section of the paper provides concise definitions of terms frequently used in the literature. Recent developments in the field of RTC include the consideration of the urban wastewater system in its entirety. This allows information from all
more » ... ts of the wastewater system to be used for control decisions and can lead to a significant improvement of the performance of the wastewater system. Some fundamental concepts of this approach are outlined. Particular emphasis in this paper is laid on methodologies of how to derive a control procedure for a given system. As an example of an RTC operational in practice, the Québec Urban Community global predictive RTC system is presented. The paper concludes with an outlook into current and future developments in the area of real time control. Ninth International Conference on Urban Drainage; Portland/Oregon, USA; September 2002 2 topic. Therefore this survey paper attempts to give an introduction to the current state of the art of real time control of urban wastewater systems. The question raised "why should we bother with real time control today?" has, at least, three valid answers: There is progress in measurement technology, the consideration of water-quality-based objectives and the integrated approach to control open up new potential, and, finally, methodologies and tools assisting in the development of control procedures have improved. Also a number of largescale case studies demonstrate that real-time control does indeed work in practice. This paper attempts to illustrate some of these concepts. Definitions and key terms This section introduces some of the fundamental concepts and terms of RTC. Subsequent sections then discuss how control procedures are actually determined for a given case study, followed by an example of an implementation of real time control in Québec. Further sections outline some important practical issues as well as current and future trends of RTC. An urban wastewater system is controlled in real time if process variables are monitored in the system and, (almost) at the same time, used to operate actuators during the flow process. In principle, the control of the process can be schematised by means of control loops (Figure 1) , which can be implemented by means of hardware components including sensors , which monitor the process evolution, actuators , which influence the process, controllers , which adjust actuators to achieve minimum deviations of the controlled process variable from its desired value (set-point), and data transmission systems transmitting data between the different devices. Disturbance measurement Actuator Process Set point pou Process measurement Controller Sensor Sensor
doi:10.1016/j.jhydrol.2004.08.010 fatcat:ejdawnoytfca7lapjf7eyvzibe