Wastewater treatment benchmark: what can be achieved with simple control?

Area of Science:

• Environmental Engineering
• Process Control
• Wastewater Treatment

Background:

• Wastewater treatment plants (WWTPs) face challenges in maintaining effluent quality under dynamic influent conditions.
• Conventional control strategies often struggle to optimize performance metrics like energy consumption and sludge production.
• The need for robust and efficient control systems in WWTPs is critical for environmental protection and operational cost reduction.

Purpose of the Study:

• To assess a simple control strategy for wastewater treatment benchmark simulations.
• To evaluate the impact of PI controllers, feedforward control, and step-feed procedures on plant performance.
• To determine optimal set-point configurations for enhanced operational efficiency and effluent compliance.

Main Methods:

• Implementation of a control strategy involving Proportional-Integral (PI) controllers, feedforward control, and a step-feed procedure.
• Focus on controlling indirect process variables that influence effluent quality.
• Analysis and optimization of set-point values under various influent scenarios (stormy, rainy, dry).

Main Results:

• Optimal set-point tuning under stormy conditions maintained performance during rainy and dry conditions.
• The proposed control strategy led to fewer effluent violations compared to existing methods.
• Significant reductions in energy consumption and sludge production were observed.
• A minor deterioration in the effluent quality criterion was noted.

Conclusions:

• The developed control strategy offers a promising approach to improve WWTP operational efficiency.
• The strategy effectively balances effluent compliance with reduced energy and sludge production.
• Set-point optimization is crucial for achieving robust performance across diverse influent conditions.