The uncertainty associated with the determination of load parameters, which is a key step in the design of wastewater treatment plants (WWTPs), was investigated on the basis of data sets from 58 WWTPs. A further analysed aspect was the organic load variations associated with variable sewage temperatures. Data from 26 WWTPs with a high inflow sampling frequency was used to simulate scenarios to investigate the effect of lower sampling frequencies through a Monte Carlo approach. The calculation of 85-percentile values for chemical oxygen demand (COD) loadings based on only 26 samples per year is associated with a variability of up to ±18%. Approximately 90 samples per year will be necessary to reduce this uncertainty for estimation of COD loadings below 10%. Hence, a low sampling frequency can potentially lead to under- or overestimation of design parameters. Through an analogous approach, it was possible to identify uncertainties of ±11% in COD loading when weekly average data was used with four samples per week. Finally, a tendency to lower COD input loads with increasing temperatures was identified, with a reduction of about 1% of the average loading per degree Celsius.
The filtrates or centrates from dewatering of digested sludges cause high internal nitrogen loads on sewage treatment plants. Especially at poor inflow C:N ratios separate treatment of these sludge liquors can significantly relieve the biological treatment stage. We developed a new process for a biological sidestream treatment with primary sludge as the carbon source for denitrification. The process has beeen tested in laboratory-scale tests and by computer simulations. The stability of the process is being investigated in a full-scale application under practical conditions.
The objective of this presented project is to use the results of an CFD simulation to automatically, systematically and reliably generate an appropriate model structure for simulation of the biological processes using CSTR activated sludge compartments. Models and dynamic simulation have become important tools for research but also increasingly for the design and optimisation of wastewater treatment plants. Besides the biological models several cases are reported about the application of computational fluid dynamics ICFD) to wastewater treatment plants. One aim of the presented method to derive model structures from CFD results is to exclude the influence of empirical structure selection to the result of dynamic simulations studies of WWTPs. The second application of the approach developed is the analysis of badly performing treatment plants where the suspicion arises that bad flow behaviour such as short cut flows is part of the problem. The method suggested requires as the first step the calculation of fluid dynamics of the biological treatment step at different loading situations by use of 3-dimensional CFD simulation. The result of this information is used to generate a suitable model structure for conventional dynamic simulation of the treatment plant by use of a number of CSTR modules with a pattern of exchange flows between the tanks automatically. The method is explained in detail and the application to the WWTP Wuppertal Buchenhofen is presented.
Welche Potenziale birgt die Abwasserwirtschaft im Sinne der Klimaschutzziele? Und welche rechtlichen Rahmenbedingungen sind dabei zu berücksichtigen? Durch innovative Ansätze sowie die Einbindung in den Energiemarkt können erhebliche Effizienzpotenziale ausgeschöpft werden.
A crucial factor for the quality and results of the on-line simulation of a municipal sewage treatment system is the provision of the requisite data in adequate quality and density. Since the measured data cannot be incorporated in a simulation model without prior processing, it should be prepared in such a way that it can be converted to the model-related input quantities. If individual input measuring signals fail, substitute value concepts must be developed which are based on the remaining information. With this it is possible to ensure the continuous provision of data. Various approaches are possible in seeking a solution to this problem. At the Wupperverband a detailed programme of investigation on the subject area of the processing of inflow data is being implemented as a component of future on-line simulation at Wuppertal-Buchenhofen STP.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.