Real-time control strategies for predenitrification-nitrification activated sludge plants biodegradation control

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Process Control

Background:

• Wastewater treatment plants (WWTPs) face challenges in consistently meeting effluent standards for ammonia and nitrate.
• Optimizing denitrification and ammonia removal requires dynamic control strategies adapting to varying influent conditions.

Purpose of the Study:

• To develop and verify real-time control strategies for ammonia and nitrate regulation in a wastewater treatment plant effluent.
• To implement a hierarchical control structure for optimizing denitrification and ammonia concentration management.

Main Methods:

• Utilized Quantitative Feedback Theory (QFT) for robust controller design.
• Implemented a hierarchical control structure with supervisory control adapting set-points for low-level controllers.
• Employed moving average filters to mitigate daily operational perturbations.
• Validated controllers through dynamic simulations using a calibrated mathematical model and real plant data.

Main Results:

• Simulations demonstrated robust performance and stability of the control strategies under varying influent loads and temperatures.
• The control system effectively regulated ammonia and nitrate concentrations, optimizing denitrification potential.
• Experimental verification in a pilot plant confirmed the controllers' efficacy with real wastewater.

Conclusions:

• The proposed hierarchical control strategies are effective for real-time management of ammonia and nitrate in WWTPs.
• The QFT-based approach ensures robust control performance, adaptable to dynamic environmental conditions.
• The developed system offers a reliable solution for maintaining effluent quality and optimizing treatment processes.