Denitrifcation rate in the mainstream deammonification

The conventional processes of biological nitrogen removal based on nitrification and denitrification does not fit properly into the concept of the circular economy. As the alternative one should consider the deammonification process, which is a combination of partial nitrification (nitritation) and Anammox processes. It consists of removing ammonium nitrogen from wastewater under anaerobic conditions by a group of autotrophic microorganisms. The result is a significant reduction in oxygen demand, while there is no a need for organic compounds that can be converted into biogas in digesters. The deammonification process can be successfully used to treat leachate from the sludge management of WWTP. Currently, research works focus on the use of this process for wastewater treatment in the mainstream of WWTP. This type of research, on a pilot scale, was also carried out at Gdańsk WWTPs. The aim of the presented research was the analysis of the possibility of a simultaneous removal of nitrates, generated during the mentioned deammonification process. The dissolved organic compounds present in the mechanically and chemically treated wastewater can be used in the denitrification process. The efficiency of the process has been determined by performing conventional denitrification rate tests (NUR). The average values of NUR 1 (2.75 mg NOx / gvss ∙ h) and NUR 2 (1.05 NOx / gvss ∙ h) were close to the values typical for mechanically treated municipal sewage. It has been shown that the denitrification process can cause an increase of total nitrogen removal efficiency in the process of deammonification of municipal wastewater. The amount of available organic compounds was sufficient to carry out the denitrification process of nitrates produced during the deammonification process.