Denitrification – A Refresher
Urban wastewater contains nitrogen—mainly organic nitrogen and ammonia.
Biological nitrogen removal mobilizes a battery of processes that converge to convert a toxic compound (ammonia) into an inert gas (nitrogen dioxide).
The main steps are:
These different steps are driven by various species of bacteria that do not share the same types of metabolism, making it critical to ensure these processes are implemented separately in time and/or space.
The conditions required for nitrification (aerobic—presence of oxygen) then denitrification (anoxic—absence of oxygen) therefore have to be integrated into successive steps.