Semi-centralized systems can offer a way of meeting the challenges of water supplies and wastewater treatment in mega cities. Waste flows like grey water, black water and organic waste are regarded as reusable resources and the concept closes the cycles of material and energy flow by waste recycling and biogas production. The article presents the specific features of semi-centralized integrated supply and treatment systems and examines demands on the measurement and control technology and process automation.

Die Messung des Chemischen Sauerstoffbedarfs (CSB) im Zulauf von Klaranlagen ist von zentraler Bedeutung fur die Optimierung und Regelung der Abbauprozesse der Nitrifikation und Denitrifikation. Allerdings ist die Messung des CSB bislang sehr zeitaufwandig und kostenintensiv, da 24-Stunden Mischproben im Labor nasschemisch analysiert werden mussen. Online-Messtechnik in Form von spektroskopischen Messgeraten (10.000 20.000 €) oder nass-chemischen Online-Analysatoren (> = 50.000 €) sind insbesondere fur kleine und mittlere Klaranlagen aus Kostengrunden keine Alternative. Eine extrem kostengunstige Alternative ist der im Folgenden beschriebene Softsensor fur CSB im Klaranlagenzulauf, der auf Basis von Standardmesstechnik im Zulauf von kleinen und mittleren kommunalen Klaranlagen sowie mit zusatzlicher Online-Messtechnik fur Trubung sowie Ammonium- und Nitratstickstoff (NH4-N und NO3-N) die aktuelle CSB-Konzentration bestimmt. Zur Entwicklung des Softsensors werden Regressionsmethoden aus dem Bereich des Machine Learning eingesetzt. Die Ergebnisse einer Entwicklungs- und Testphase an der Klaranlage Rospe in Gummersbach zeigen, dass die Werte des Softsensors sehr gut mit den Originaldaten ubereinstimmen. Die Korrelationswerte beim Vergleich mit CSB-Messungen liegen bei der Regression mit Support Vector Regression bei 0,98 mit einem RSME von 2,45 mg/l.

Dieser Beitrag befasst sich mit dem Konzept semizentraler Ver- und Entsorgungssysteme, das es ermoglicht, die Herausforderungen der Wasserver- und Abwasserentsorgung in Megastadten zu losen. Das Konzept basiert auf der Idee, Abfallstoffe, wie Schmutzwasser und organische Abfalle, als Wertstoff zu betrachten und durch energetische Verwertung sowie durch Ressourcenwiederverwendung den Energie- und Stoffkreislauf zu schliesen. Die Autoren stellen die besonderen Merkmale semizentraler integrierter Ver- und Entsorgungssysteme vor und betrachten entstehende Anforderungen an die MSR-Technik und die Prozessautomatisierung. Water and Wastewater Management in Mega Cities Semi-Centralized Supply and Treatment Systems Abstract: Semi-centralized systems can offer a way of meeting the challenges of water supplies and wastewater treatment in mega cities. Waste flows like grey water, black water and organic waste are regarded as reusable resources and the concept closes the cycles of material and energy flow by waste recycling and biogas production. The article presents the specific features of semi-centralized integrated supply and treatment systems and examines demands on the measurement and control technology and process automation.

The in-line measurement of COD and NH4-N in the WWTP inflow is crucial for the timely monitoring of biological wastewater treatment processes and for the development of advanced control strategies for optimized WWTP operation. As a direct measurement of COD and NH4-N requires expensive and high maintenance in-line probes or analyzers, an approach estimating COD and NH4-N based on standard and spectroscopic in-line inflow measurement systems using Machine Learning Techniques is presented in this paper. The results show that COD estimation using Radom Forest Regression with a normalized MSE of 0.3, which is sufficiently accurate for practical applications, can be achieved using only standard in-line measurements. In the case of NH4-N, a good estimation using Partial Least Squares Regression with a normalized MSE of 0.16 is only possible based on a combination of standard and spectroscopic in-line measurements. Furthermore, the comparison of regression and classification methods shows that both methods perform equally well in most cases.

Dieser Beitrag befasst sich mit dem Konzept semizentraler Ver- und Entsorgungssysteme, das es ermöglicht, die Herausforderungen der Wasserver- und Abwasserentsorgung in Megastädten zu lösen. Das Konzept basiert auf der Idee, Abfallstoffe, wie Schmutzwasser und organische Abfälle, als Wertstoff zu betrachten und durch energetische Verwertung sowie durch Ressourcenwiederverwendung den Energie- und Stoffkreislauf zu schließen. Die Autoren stellen die besonderen Merkmale semizentraler integrierter Ver- und Entsorgungssysteme vor und betrachten entstehende Anforderungen an die MSR-Technik und die Prozessautomatisierung.

Membrane wastewater treatment plants (WWTPs) have several advantages compared with conventionally designed WWTPs with classical purification techniques. The filtration process is the key to their commercial success in Germany with respect to energy consumption and effectiveness, enabled by the optimization of filtration using a dynamic simulation model. This work is focused on the development of a robust, flexible and practically applicable membrane simulation model for submerged hollow-fibre and flat-sheet membrane modules. The model is based on standard parameters usually measured on membrane WWTPs. The performance of the model is demonstrated by successful calibration and validation for three different full-scale membrane WWTPs achieving good results. Furthermore, the model is combinable with Activated Sludge Models.

The optimization of relaxation and filtration times of submerged microfiltration flat modules in membrane bioreactors used for municipal wastewater treatment is essential for efficient plant operation. However, the optimization and control of such plants and their filtration processes is a challenging problem due to the underlying highly nonlinear and complex processes. This paper presents the use of genetic algorithms for this optimization problem in conjunction with a fully calibrated simulation model, as computational intelligence methods are perfectly suited to the nonconvex multi-objective nature of the optimization problems posed by these complex systems. The simulation model is developed and calibrated using membrane modules from the wastewater simulation software GPS-X based on the Activated Sludge Model No.1 (ASM1). Simulation results have been validated at a technical reference plant. They clearly show that filtration process costs for cleaning and energy can be reduced significantly by intelligent process optimization.

An optimal control of wastewater treatment plants (WWTP) has to account for changes in the bio-chemical state of the bioreactors. As many process variables of a WWTP are not measurable online, the development of an efficient control strategy is one of the greatest challenges in the optimization of WWTP operation. This paper presents an approach, which combines the use of Self-Organizing Maps (SOM) and a clustering algorithm to identify operational patterns in WWTP process data. These patterns provide a basis for the optimization of controller set points that are well suited for the previously identified operation regimes of the plant. The optimization is performed using Genetic Algorithms. This approach was developed, tested and validated on a simulation model based on the Activated Sludge Model No.1 (ASM1). The results of this state-based control indicate that the presented methodology is a promising and useful control strategy that is definitely able to address the distinctive energy and effluent limit challenges faced by WWTP operators.