It has been known that sewage containing high-concentration nitrogen affects the efficiency of municipal wastewater
treatment plants harmfully. Therefore, research has been actively conducted to treat sewage containing high-concentration
nitrogen. The current study has analyzed organic compounds, conducted foaming tests, and operated a laboratory-level
nitritation reactor with the subjects of anaerobic digester supernatant and livestock wastewater which are the typical kinds of
sewage containing high-concentration nitrogen. According to the results of analyzing organic compounds, soluble inert
components form the largest part of anaerobic digester supernatant while particle biodegradable components occupy the most
part of livestock wastewater. About the retention time proper for the reaction of nitritation, anaerobic digester supernatant
shows 2 days while livestock wastewater indicates 6 days. It seems that the difference in the proper retention time is
resulted from the difference of properties in organic compounds and ammonium nitrogen concentration. In addition, livestock
wastewater’s reactor foam is generated comparatively more than anaerobic digester supernatant’s, but it tends to be
eliminated faster. It is expected that the findings of this study can be utilized as foundational data afterwards in applying
the reaction of nitritation to municipal wastewater treatment plants.