The respiration rate has generated much interest as a means of monitoring and controlling the activated sludge process because it is directly associated with both biomass growth and substrate removal. Respirometry has long been recognized as a valuable tool for controlling the activated sludge process, and as a result, many respirometry-based control strategies have been proposed in the literature. This study has developed a benchmark and methodology for conducting simulation studies to test the proposed control strategies within a complete and consistent set of process conditions. The benchmark consists of a complete set of influent conditions, a standard activated sludge plant configuration, models for the activated sludge process and the secondary clarification process, as well as values for the model parameters and initial values for the state variables. The benchmark provided the framework for the development of the simulation-based methodology. The methodology uses the benchmark, and includes a set of guidelines for implementing a control strategy in the benchmark plant and a set of tests for evaluating the performance and benefits of a proposed control system. The benchmark and methodology were then applied to test selected control strategies from the literature. (Abstract shortened by UMI.).

Ebook only (available soon) The report describes the principles of measurement of respiration rate, the transformation of measurement data into other types of information, and the application of the obtained information in process control strategies. Some fundamental concepts on biological respiration and process control are provided to assist the reader with understanding the principles. A structured overview comprises some eighty control strategies in which respirometry plays a role. To enable the reader to consult the information sources, an extensive literature list of over 500 references in included and classified into six themes. Contents Fundamentals of Respiration Measuring Principles Measured and Deduced Variables Elementary Control Concepts Respirometry in Control of the Activated Sludge Process Summary and Perspectives. Scientific and Technical Report No.7 Also Available Respirometry in Control of the Activated Sludge Process: Benchmarking Control Strategies

Mathematical Modelling and Computer Simulation of Activated Sludge Systems – Second Edition provides, from the process engineering perspective, a comprehensive and up-to-date overview regarding various aspects of the mechanistic (“white box”) modelling and simulation of advanced activated sludge systems performing biological nutrient removal. In the new edition of the book, a special focus is given to nitrogen removal and the latest developments in modelling the innovative nitrogen removal processes. Furthermore, a new section on micropollutant removal has been added. The focus of modelling has been shifting in the last years to models that can describe the performance of a whole plant (plant-wide modelling). The expanded part of this new edition introduces models describing the most important processes interrelated with the mainstream activated sludge systems as well as models describing the energy balance, operating costs and environmental impact. The complex process evaluation, including minimization of energy consumption and carbon footprint, is in line with the present and future wastewater treatment goals. By combining a general introduction and a textbook, this book serves both intermediate and more experienced model users, both researchers and practitioners, as a comprehensive guide to modelling and simulation studies. The book can be used as a supplemental material at graduate and post-graduate levels of wastewater engineering/modelling courses.

Wastewater treatment plants are large non-linear systems subject to large perturbations in wastewater flow rate, load and composition. Nevertheless these plants have to be operated continuously, meeting stricter and stricter regulations. Many control strategies have been proposed in the literature for improved and more efficient operation of wastewater treatment plants. Unfortunately, their evaluation and comparison – either practical or based on simulation – is difficult. This is partly due to the variability of the influent, to the complexity of the biological and biochemical phenomena and to the large range of time constants (from a few minutes to several days). The lack of standard evaluation criteria is also a tremendous disadvantage. To really enhance the acceptance of innovative control strategies, such an evaluation needs to be based on a rigorous methodology including a simulation model, plant layout, controllers, sensors, performance criteria and test procedures, i.e. a complete benchmarking protocol. This book is a Scientific and Technical Report produced by the IWA Task Group on Benchmarking of Control Strategies for Wastewater Treatment Plants. The goal of the Task Group includes developing models and simulation tools that encompass the most typical unit processes within a wastewater treatment system (primary treatment, activated sludge, sludge treatment, etc.), as well as tools that will enable the evaluation of long-term control strategies and monitoring tasks (i.e. automatic detection of sensor and process faults). Work on these extensions has been carried out by the Task Group during the past five years, and the main results are summarized in Benchmarking of Control Strategies for Wastewater Treatment Plants. Besides a description of the final version of the already well-known Benchmark Simulation Model no. 1 (BSM1), the book includes the Benchmark Simulation Model no. 1 Long-Term (BSM1_LT) – with focus on benchmarking of process monitoring tasks – and the plant-wide Benchmark Simulation Model no. 2 (BSM2). Authors: Krist V. Gernaey, Technical University of Denmark, Lyngby, Denmark, Ulf Jeppsson, Lund University, Sweden, Peter A. Vanrolleghem, Université Laval, Quebec, Canada and John B. Copp, Primodal Inc., Hamilton, Ontario, Canada