Activated sludge model 2d calibration with full-scale WWTP data: comparing model parameter identifiability with...

Area of Science:

• Environmental Engineering
• Process Modeling
• Wastewater Treatment

Background:

• Wastewater treatment plants (WWTPs) require accurate models for effective upgrades and operation.
• The Activated Sludge Model 2d (ASM2d) is a common tool, but its calibration can be complex and require expert knowledge.
• Systematic calibration using plant data can improve model reliability and operational insights.

Purpose of the Study:

• To develop and validate a systematic parameter calibration methodology for the ASM2d model applied to a full-scale WWTP.
• To assess the impact of influent characteristics and operating variables on model performance.
• To evaluate the robustness of WWTP control strategies against disturbances and model uncertainties.

Main Methods:

• Developed a model for a full-scale WWTP (Manresa, Catalonia, Spain).
• Employed a methodology based on the Fisher information matrix for systematic parameter calibration of the ASM2d.
• Characterized influent and assessed confidence intervals for calibrated parameters.
• Investigated the effect of influent and operating variables by using them as calibration parameters, inverting the traditional approach.

Main Results:

• Successfully calibrated the ASM2d model without requiring expert knowledge, converting plant database into valuable information.
• Demonstrated that influent and operating variables significantly affect model fit, providing insights into plant sensitivity.
• Evaluated the capacity of operational variables to counteract external disturbances and model uncertainties.
• Identified useful input and output variables for decentralized control structures based on operational variable influence.

Conclusions:

• The developed methodology offers a simplified and effective approach to WWTP model calibration and upgrades.
• The study highlights the importance of considering influent and operational variables for robust WWTP control.
• This approach provides a foundation for optimizing WWTP performance and implementing advanced control strategies.