This chapter provides a comprehensive overview of the main steps for algorithmic sensor signal quality assessment, which can enhance the decision-making process for water resource recovery facility (WRRF) operation and optimization. It introduces the concept of redundancy as the basis for data quality assessment. It also explains the typical data processing pipeline, which consists of preliminary analysis, data pre-processing, and specific algorithmic approaches. Each of these processes is presented and discussed in three separate sections. Importantly, this chapter introduces the main approaches for data quality assessment, provides guidelines for selecting the most suitable one and the key performance indicators to evaluate them and explains how to collect metadata through such an algorithmic approach.
The respiration rate of activated sludge has generated much interest, because it is an essential variable in the activated sludge process and provides information on biomass activity and concentration of waste components. Recognising the need for an extensive evaluation of respirometry in control of the activated sludge process, published Scientific and Technical Report (STR7): Respirometry in Control of the Activated Sludge Process: Principles, which included the biological background, measuring principles, measured and deduced variables, an introduction to control system principles and an overview of proposed and applied control strategies. To complete the work, a second STR: Respirometry in Control of the Activated Sludge Process: Benchmarking Control Strategies was commissioned and, through the generous support of 14 corporate sponsors, a well-defined project was set up with the aim to accomplish an ambitious mission: the development of a simulation protocol (known as the IWA Simulation Benchmark) and the unbiased evaluation of many respirometry-based control strategies. This Report includes a complete description of the simulation protocol including model plants, simulation procedures and evaluation criteria. Also included in this STR is an overview of the strategy evaluations and a look into the future of respirometry as the basis for control. Finally, to ease the transition from paper to computer, and increase the application of the Simulation Benchmark, a CD is included with many benchmark files and control strategy layouts generated using a variety of simulation platforms including GPS-XTM, STOATTM and WESTTM. This Report will be an invaluable source of information for practitioners and consultants dealing with the operation and control of activated sludge processes, developers of control systems, control software and simulation software, and manufacturers of respirometers and other environmental instruments in all industries dealing with toxic wastes. Scientific and Technical Report No. 11 Also available: Respiromentry in Control of the Activated Sludge Process: Principles
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).This title belongs to Scientific and Technical Report SeriesISBN: 9781780401171 (eBook)ISBN: 9781843391463 (Print)
Key developments of instrumentation, control and automation (ICA) applications in wastewater systems during the past 40 years are highlighted in this paper. From the first ICA conference in 1973 through to today there has been a tremendous increase in the understanding of the processes, instrumentation, computer systems and control theory. However, many developments have not been addressed here, such as sewer control, drinking water treatment and water distribution control. It is hoped that this review can stimulate new attempts to more effectively apply control and automation in water systems in the coming years.
As the work of the IWA Task Group on Benchmarking of Control Strategies for wastewater treatment plants (WWTPs) is coming to an end, it is essential to disseminate the knowledge gained. For this reason, all authors of the IWA Scientific and Technical Report on benchmarking have come together to provide their insights, highlighting areas where knowledge may still be deficient and where new opportunities are emerging, and to propose potential avenues for future development and application of the general benchmarking framework and its associated tools. The paper focuses on the topics of temporal and spatial extension, process modifications within the WWTP, the realism of models, control strategy extensions and the potential for new evaluation tools within the existing benchmark system. We find that there are major opportunities for application within all of these areas, either from existing work already being done within the context of the benchmarking simulation models (BSMs) or applicable work in the wider literature. Of key importance is increasing capability, usability and transparency of the BSM package while avoiding unnecessary complexity.