The use of aquasim for estimating parameters of activated sludge models

1995 ◽  
Vol 31 (2) ◽  
pp. 135-147 ◽  
Author(s):  
Peter Reichert ◽  
Reto von Schulthess ◽  
Daniel Wild
Keyword(s):  
Parameter Estimation ◽  
Computer Program ◽  
Activated Sludge ◽  
Single Parameter ◽  
Aquatic Systems ◽  
Parameter Identifiability ◽  
Sensitivity Functions ◽  
Activated Sludge Models

The capabilities of a new computer program for the identification and simulation of aquatic systems (AQUASIM) with respect to parameter estimation of activated sludge models are outlined. The example of the evaluation of two denitrification experiments is used to demonstrate the flexibility of the program with respect to model definition, the possibility of combining several experiments with universal and experiment-specific parameters and several target variables to give a single parameter estimation, and the utility of sensitivity functions for assessing parameter identifiability. The provision for all these tasks makes AQUASIM a very useful tool for parameter estimation of activated sludge models.

Assessment on activated sludge models for acetate biodegradation under aerobic conditions

2009 ◽  
Vol 60 (4) ◽  
pp. 983-994 ◽  
Author(s):  
M. A. Hoque ◽  
V. Aravinthan ◽  
N. M. Pradhan
Keyword(s):  
Parameter Estimation ◽  
Activated Sludge ◽  
Model Calibration ◽  
Aerobic Biodegradation ◽  
Batch Experiments ◽  
Storage Model ◽  
Biodegradation Process ◽  
Ammonia Degradation ◽  
And Storage ◽  
Activated Sludge Models

A comparison of four different established models along with parameter estimation was carried out in order to explain the aerobic biodegradation of acetate in an activated sludge system. These models were investigated using experimental OUR data from batch experiments of three different concentration studies. Model calibration reveals that ASM1 model is not suitable to explain the observed experimental OUR during the famine phase implying storage compounds could play an important role during that stage. Besides, the model corresponds to the accumulation concept and is not well fitted for all concentrations studies though it includes the storage phenomena. Both the ASM3 model and the model for simultaneous storage and growth on substrate can well describe the acetate biodegradation process, however the OUR data alone is not sufficient to justify the suitability of those models. Simulated profiles using the model outputs demonstrate that storage is overestimated while ammonia degradation is underestimated in ASM3 compared to simultaneous growth and storage model. The current study also gives reasonable outcomes related to parameter estimation as compared with previous study which is statistically interpreted in this paper.

Parameter Estimation and Sensitivity Analysis of an Activated Sludge Model Using Monte Carlo Simulation and the Analyst's Involvement

1993 ◽  
Vol 28 (11-12) ◽  
pp. 219-229 ◽  
Author(s):  
Marcos von Sperling
Keyword(s):  
Sensitivity Analysis ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Parameter Estimation ◽  
Activated Sludge ◽  
Model Calibration ◽  
Coefficient Of Determination ◽  
Operational Control ◽  
Activated Sludge Model ◽  
Activated Sludge Models

The present work describes an adaptation of the regionalized sensitivity analysis based on Monte Carlo simulations for the parameter estimation and sensitivity analysis of an activated sludge model. The procedure described should be used when observed data are available for the model calibration, which is nevertheless still limited by the problems inherent to activated sludge models (uncertainty and lack of identifiability). The selection between good and bad performance of the model is judged based on the Coefficient of Determination. The application of the procedure to an 11-parameter 4-state dynamic activated sludge model used for operational control was considered satisfactory. The method is simple and yet robust, and the analyst's involvement in the interpretation of the results and decision upon the next steps to be taken increases its controllability.

A simplified method to assess structurally identifiable parameters in Monod-based activated sludge models

2003 ◽  
Vol 37 (12) ◽  
pp. 2893-2904 ◽  
Author(s):  
Britta Petersen ◽  
Krist Gernaey ◽  
Martijn Devisscher ◽  
Denis Dochain ◽  
Peter A. Vanrolleghem
Keyword(s):  
Activated Sludge ◽  
Simplified Method ◽  
Activated Sludge Models

A systematic approach for model verification: application on seven published activated sludge models

2010 ◽  
Vol 61 (4) ◽  
pp. 825-839 ◽  
Author(s):  
H. Hauduc ◽  
L. Rieger ◽  
I. Takács ◽  
A. Héduit ◽  
P. A. Vanrolleghem ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Systematic Approach ◽  
Model Development ◽  
Model Verification ◽  
Software Implementation ◽  
Model Description ◽  
Kinetic Rate ◽  
Simulation Results ◽  
Activated Sludge Models

The quality of simulation results can be significantly affected by errors in the published model (typing, inconsistencies, gaps or conceptual errors) and/or in the underlying numerical model description. Seven of the most commonly used activated sludge models have been investigated to point out the typing errors, inconsistencies and gaps in the model publications: ASM1; ASM2d; ASM3; ASM3 + Bio-P; ASM2d + TUD; New General; UCTPHO+. A systematic approach to verify models by tracking typing errors and inconsistencies in model development and software implementation is proposed. Then, stoichiometry and kinetic rate expressions are checked for each model and the errors found are reported in detail. An attached spreadsheet (see http://www.iwaponline.com/wst/06104/0898.pdf) provides corrected matrices with the calculations of all stoichiometric coefficients for the discussed biokinetic models and gives an example of proper continuity checks.

Important limitations in the modeling of activated sludge: biased calibration of the hydrolysis process

2002 ◽  
Vol 45 (12) ◽  
pp. 23-36 ◽  
Author(s):  
G. Insel ◽  
Ö. Karahan Gül ◽  
D. Orhon ◽  
P.A. Vanrolleghem ◽  
M. Henze
Keyword(s):  
Activated Sludge ◽  
Hydrolysis Rate ◽  
Utilization Rate ◽  
Oxygen Utilization ◽  
Experimental Assessment ◽  
Experimental Database ◽  
Hydrolysis Process ◽  
Biochemical Mechanisms ◽  
Oxygen Utilization Rate ◽  
Activated Sludge Models

The merit of activated sludge models depends on the accuracy and reliability of the information they contain on the wastewater to be treated and the biochemical mechanisms involved. In most advanced calibration studies, respirometry i.e. the measurement of the oxygen utilization rate, (OUR), provides the majority of the required experimental database. However, currently used procedures still involve a number of basic and practical problems. Model evaluation of the OUR data may generate a distorted image of the processes involved. Hydrolysis is the most important, yet the most vulnerable process as far as the experimental assessment of accurate kinetic parameters is concerned. This study intends to provide an overview of major experimental limitations in the modeling of activated sludge, with emphasis on the appropriate experimental design for the assessment of the hydrolysis rate.

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