Automation of aeration control based on nitrogen parameters at the New Water Line of the Central Wastewater Treatment Plant in Prague

Schematic comparison of aeration control strategies at the Prague Central Wastewater Treatment Plant. The abstract is divided into three panels. LEFT PANEL: Conventional control uses a fixed O₂ setpoint and fixed aeration cycles, resulting in NOx accumulation. MIDDLE PANEL: Smart automated control adjusts the O₂ setpoint dynamically based on ratio N-NOx/N-NH4 and threshold concentrations of N-NH₄ and N-NOx, with minimum and maximum aeration times and O₂ limits. RIGHT PANEL: This approach maintains stable ammonium levels, reduces NOx accumulation, and increases nitrogen removal efficiency from 82% to 86%. This paper describes the implementation of automated aeration control at the New Water Line (NWL) of the Central Wastewater Treatment Plant in Prague. The system utilizes a dynamic oxygen setpoint based on N-NH4 concentration and intermittent aeration regulated by the N-NOx/N-NH4 ratio, with defined boundary conditions. The results indicate that the new control method led to an increase in total nitrogen (Ntot) removal efficiency in the biological stage in 2025. The improved Ntot removal efficiency achieved using automatic control, compared to the original aeration control method, was confirmed by both long-term monitoring and targeted operational tests.