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Software sensors for highly uncertain WWTPs: a new approach based on interval observers
V Alcaraz-González1, J Harmand, A Rapaport
1Laboratoire de Biotechnologie de l'Environnement, INRA-LBE, Narbonne, France.
Water Research
|August 3, 2002
Summary
A new robust interval observer estimates unmeasured variables in wastewater treatment, offering reliable performance despite process uncertainties. This method enhances monitoring for industrial anaerobic reactors.
Area of Science:
- Environmental Engineering
- Biochemical Engineering
- Control Systems
Background:
- Industrial wine distillery wastewater poses treatment challenges due to complex composition.
- Accurate monitoring of key parameters is crucial for optimizing anaerobic digestion.
- Unmeasured variables like microbial populations and chemical oxygen demand hinder real-time process control.
Purpose of the Study:
- To implement and validate a novel robust interval observer for continuous fixed-bed anaerobic reactors.
- To estimate unmeasured variables essential for process monitoring and control.
- To demonstrate the observer's robustness against process uncertainties and disturbances.
Main Methods:
- Implementation of a robust interval observer on a 1 m3 continuous fixed-bed anaerobic reactor.
- Utilizing on-line measurements including flow rates, volatile fatty acids, and total inorganic carbon.
- Generating guaranteed intervals for unmeasured variables such as microbial concentrations and chemical oxygen demand.
Main Results:
- The interval observer successfully estimated unmeasured variables, providing guaranteed intervals.
- The observer demonstrated independence from disturbances and uncertainties in initial conditions, kinetics, and process inputs.
- Practical implementation validated the observer's effectiveness in a real-world wastewater treatment scenario.
Conclusions:
- The robust interval observer provides a reliable method for monitoring unmeasured variables in anaerobic wastewater treatment.
- This approach enhances process understanding and control by overcoming limitations of traditional monitoring.
- The observer's robustness makes it suitable for challenging industrial applications like wine distillery wastewater treatment.
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