Experimental detemination of Half-Saturation Coefficient for Nitrifying Bacteria by Infinite Dilution Method

무한희석법(無限稀釋法)을 이용한 질산화(窒酸化) 미생물(微生物) 반포화계수(半飽和係數) 결정(決定)에 관한 실험적(實驗的) 연구(硏究)

To remove nitrogen from wastewater, ammonia nitrogen has to be oxidized to nitrate nitrogen before denitrification reaction which converts nitrate nitrogen to nitrogen gas. In order to understand nitrification, several mathematical models had been proposed and Monod type model has been accepted internationally. Since Monod type model consists of maximum substrate utilization rate, substrate concentration and half-saturation coefficient, these values have to be addressed before using Monod type model. Several experimental procedures to determine half-saturation coefficient have been developed, however, Infinite dilution method was known to be time saving procedure. In this study, the mathematical equations and experimantal procedures for Infinite dilution method are presented and this method is used to determine half-Saturation coefficient for nitrifying bacteria. As results, Infinite dilution method is proved that this coefficient can be determined within 8 hours and the values of half-saturation coefficient has a range of 0.728 and $0.455gNH_4{^+}-N/m^3$ and the average has $0.580gNH_4{^+}-N/m^3$ through 5 sets of experiments.