Simultaneous estimation of sludge biological activity and influent nitrogen load using ORP and DO dynamics

Area of Science:

• Environmental Engineering
• Biotechnology
• Wastewater Treatment

Background:

• Activated sludge processes are crucial for wastewater treatment.
• Accurate estimation of key parameters like nitrification and denitrification rates is essential for process optimization.
• Intermittent aeration strategies are employed to enhance efficiency but complicate parameter monitoring.

Purpose of the Study:

• To develop a novel optimization strategy for estimating wastewater parameters under intermittent aeration.
• To utilize readily available measurements (oxydo-reduction potential and dissolved oxygen) for parameter identification.
• To validate the proposed method using both simulated and experimental data.

Main Methods:

• A Simplex optimization algorithm was employed to identify process parameters.
• A reduced model derived from the Activated Sludge Model 1 (ASM1) was used for simulation.
• The cost function minimized the error between experimental and simulated cycles (aerobic followed by anoxic).

Main Results:

• The proposed method accurately predicted experimental oxygen, ammonium, and nitrate profiles.
• Nitrifiable nitrogen concentration and removal rates were effectively estimated.
• Validation was successful using simulated data from the COST action 624 benchmark and real experimental data.

Conclusions:

• The developed optimization strategy provides a reliable method for estimating critical parameters in intermittently aerated activated sludge systems.
• The approach's reliance on simple measurements (dissolved oxygen and redox potential) makes it practical for real-world applications.
• The validated estimations of nitrogen and COD removal rates contribute to better wastewater treatment process control and management.