Calibration of an Activated Sludge Model Based on Human Expertise and on a Mathematical Optimization Technique – a Comparison

1992 ◽  
Vol 25 (6) ◽  
pp. 141-148 ◽  
Author(s):  
Oskar Wanner ◽  
Jürg Kappeier ◽  
Willi Gujer
Keyword(s):  
Activated Sludge ◽  
Optimization Technique ◽  
Mathematical Optimization ◽  
The Other ◽  
Sequential Procedure ◽  
Alternative Methods ◽  
Model Parameters ◽  
Activated Sludge Model ◽  
Parameter Values ◽  
Mathematical Optimization Technique

Two alternative methods, which both can be used to estimate some of the kinetic parameters of the IAWPRC Activated Sludge Model Nr. 1, are compared. By one method, which is based on professional experience and expertise, the unknown parameter values are determined one after the other by a sequential procedure. By the other method, the parameter values are determined simultaneously by use of a mathematical optimization technique. Both methods allow a good fit of a set of 25 experimental oxygen respiration rate time-series and yield accurate estimates of the model parameters. The sequential procedure can readily be employed for the evaluation of single experiments. The optimization technique is more suitable for the evaluation of larger data sets and allows for additional analysis of the data.

Model Calibration for the High-Purity Oxygen Activated Sludge Process – Algorithm Development and Evaluation

1993 ◽  
Vol 28 (11-12) ◽  
pp. 163-171 ◽  
Author(s):  
Weibo (Weber) Yuan ◽  
David Okrent ◽  
Michael K. Stenstrom
Keyword(s):  
Activated Sludge ◽  
High Purity ◽  
Model Calibration ◽  
Process Model ◽  
Model Parameters ◽  
Complex Method ◽  
Activated Sludge Process ◽  
Activated Sludge Model ◽  
Kinetic Coefficients ◽  
Calibration Algorithm

A model calibration algorithm is developed for the high-purity oxygen activated sludge process (HPO-ASP). The algorithm is evaluated under different conditions to determine the effect of the following factors on the performance of the algorithm: data quality, number of observations, and number of parameters to be estimated. The process model used in this investigation is the first HPO-ASP model based upon the IAWQ (formerly IAWPRC) Activated Sludge Model No. 1. The objective function is formulated as a relative least-squares function and the non-linear, constrained minimization problem is solved by the Complex method. The stoichiometric and kinetic coefficients of the IAWQ activated sludge model are the parameters focused on in this investigation. Observations used are generated numerically but are made close to the observations from a full-scale high-purity oxygen treatment plant. The calibration algorithm is capable of correctly estimating model parameters even if the observations are severely noise-corrupted. The accuracy of estimation deteriorates gradually with the increase of observation errors. The accuracy of calibration improves when the number of observations (n) increases, but the improvement becomes insignificant when n>96. It is also found that there exists an optimal number of parameters that can be rigorously estimated from a given set of information/data. A sensitivity analysis is conducted to determine what parameters to estimate and to evaluate the potential benefits resulted from collecting additional measurements.

scholarly journals A practical protocol for calibration of nutrient removal wastewater treatment models

2011 ◽  
Vol 13 (4) ◽  
pp. 575-595 ◽  
Author(s):  
Giorgio Mannina ◽  
Alida Cosenza ◽  
Peter A. Vanrolleghem ◽  
Gaspare Viviani
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Model Calibration ◽  
Wastewater Treatment Plants ◽  
Optimal Parameter ◽  
Model Parameters ◽  
Activated Sludge Model ◽  
Treatment Models ◽  
Glue Method

Activated sludge models can be very useful for designing and managing wastewater treatment plants (WWTPs). However, as with every model, they need to be calibrated for correct and reliable application. Activated sludge model calibration is still a crucial point that needs appropriate guidance. Indeed, although calibration protocols have been developed, the model calibration still represents the main bottleneck to modelling. This paper presents a procedure for the calibration of an activated sludge model based on a comprehensive sensitivity analysis and a novel step-wise Monte Carlo-based calibration of the subset of influential parameters. In the proposed procedure the complex calibration issue is tackled both by making a prior screening of the most influential model parameters and by simplifying the problem of finding the optimal parameter set by splitting the estimation task into steps. The key point of the proposed step-wise procedure is that calibration is undertaken for sub-groups of variables instead of solving a complex multi-objective function. Moreover, even with this step-wise approach parameter identifiability issues may occur, but this is dealt with by using the general likelihood uncertainty estimation (GLUE) method, that so far has rarely been used in the field of wastewater modelling. An example from a real case study illustrates the effectiveness of the proposed methodology. Particularly, a model was built for the simulation of the nutrient removal in a Bardenpho scheme plant. The model was successfully and efficiently calibrated to a large WWTP in Sicily.

Application of the IAWQ activated sludge model to nutrient removal process

1997 ◽  
Vol 35 (8) ◽  
pp. 111-118 ◽  
Author(s):  
T. Mino ◽  
D. C. San Pedro ◽  
S. Yamamoto ◽  
T. Matsuo
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Hydrolysis Rate ◽  
Substrate Uptake ◽  
Nitrogen And Phosphorus ◽  
State Behavior ◽  
Activated Sludge Model ◽  
Static Data ◽  
The Moment ◽  
Parameter Values

IAWQ Activated Sludge Model No.2, with the parameter values recommended by the IAWQ Task Group, was capable of predicting the behavior of a nutrient removal activated sludge pilot plant in Japan rather well except for the profile of NH4-N and NOx-N. The model was calibrated for the process and procedures for the calibration of the model are proposed. By applying the proposed calibration procedures, Activated Sludge Model No.2 has been satisfactorily calibrated to simulate the steady state behavior of the process in terms of organic matter and nitrogen removal. but, sometimes, selection of the specific growth rate of nitrifiers gives very sensitive effect on nitrate concentration in the effluent. It is indicated that the rate of anaerobic processes is affected by hydrolysis of particulate organic or slowly biodegradable substrates, and the hydrolysis can be the rate limiting step of the removal of organic matters or, sometimes, nitrogen and phosphorus. At the moment, it is rather risky to estimate the anaerobic hydrolysis rate, the anaerobic substrate uptake rate by phosphate accumulating organisms and the PHA yield with respect to polyphosphate utilization simultaneously only by using static data. The present case shows how relevant calibration procedures can be developed with limited static data.

Activated sludge modelling: development and potential use of a practical applications database

2011 ◽  
Vol 63 (10) ◽  
pp. 2164-2182 ◽  
Author(s):  
H. Hauduc ◽  
L. Rieger ◽  
T. Ohtsuki ◽  
A. Shaw ◽  
I. Takács ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Practical Experience ◽  
Model Parameters ◽  
Practical Applications ◽  
Biokinetic Model ◽  
Starting Point ◽  
Technical Report ◽  
Typical Parameter ◽  
Parameter Values ◽  
Activated Sludge Models

This study aims at synthesizing experiences in the practical application of ASM type models. The information is made easily accessible to model users by creating a database of modelling projects. This database includes answers to a questionnaire that was sent out to model users in 2008 to provide inputs for a Scientific and Technical Report of the IWA Task Group on Good Modelling Practice – Guidelines for use of activated sludge models, and a literature review on published modelling projects. The database is analysed to determine which biokinetic model parameters are usually changed by modellers, in which ranges, and what values are typically used for seven selected activated sludge models. These results should help model users in the calibration step, by providing typical parameter values as a starting point and ranges as a guide. However, the proposed values should be used with great care since they are the result of averaging practical experience and not taking into account specific parameter correlations.

Updated Activated Sludge Model n°1 Parameter Values for Improved Prediction of Nitrogen Removal in Activated Sludge Processes: Validation at 13 Full-scale Plants

2009 ◽  
Vol 81 (9) ◽  
pp. 858-865 ◽  
Author(s):  
Jean-Marc Choubert ◽  
Anne-Emmanuelle Stricker ◽  
Aurélien Marquot ◽  
Yvan Racault ◽  
Sylvie Gillot ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Full Scale ◽  
Activated Sludge Model ◽  
Parameter Values ◽  
Activated Sludge Processes
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