Robust control of water quality in horizontal sub-surface flow wetlands using decentralized quantitative feedback...

Area of Science:

• Environmental Engineering
• Water Quality Management
• Control Systems

Background:

• Wetlands are crucial for water purification, but their performance can be affected by plant variability.
• Effective regulation of pollutants like nitrogen and organic carbon is essential for maintaining water quality.

Purpose of the Study:

• To develop and validate a robust control strategy for managing key water quality parameters in a sub-surface flow horizontal wetland.
• To address plant uncertainty in wetland systems through advanced control techniques.

Main Methods:

• Quantification of plant uncertainty using measurement data.
• Implementation of a decentralized quantitative feedback theory (QFT) based robust control strategy.
• Integration of feed-forward and feedback control mechanisms for enhanced performance.

Main Results:

• The proposed control strategy robustly regulates Organic Nitrogen, Ammonia Nitrogen, Nitrate Nitrogen, Dissolved Organic Carbon, and Dissolved Oxygen.
• Numerical simulations and hardware-in-loop (HIL) implementation confirmed the system's effectiveness.
• The control structure successfully minimized loop interactions and ensured stability and disturbance rejection.

Conclusions:

• A robust and effective control system for wetland water quality management has been demonstrated.
• The decentralized QFT approach provides a reliable method for handling plant uncertainty in environmental systems.
• The findings support the use of advanced control strategies for optimizing wetland treatment processes.