In ASM model, organic matters are classified according to their characteristics and general classification into COD
and BOD cannot satisfy conditions required by ASM. In this study, it was performed to study classification of organic
matters required by ASM on the basis of microorganisms’ respiration rate subject to wastewater and sludge treatment.
As results of analysis of the organic matter’s appearance, it was found that there were some differences in composition
of organic matters between wastewaters. It is considered that it is an important characteristic of wastewater that
should be understood in treating wastewater in each process. Therefore, it is considered that appearance of organic
matters in each wastewater identified by this study will be used as important basic data for operation of municipal
wastewater treatment plant. It was identified that SS was an important factor affecting nitrification through organic
matter and ammonium nitrogen change analysis according to reaction time in the nitrification. It is considered that
the nitrification has close relationship with choice of optimal retention time.