해양 현장관측을 통한 해양방류 하수플륨의 통계적 근역혼합 특성

Abstract

The effects of DO and aeration time, traditional nitrification inhibition factors, on nitrite (NO2-) accumulation were studied to find the practical nitrite build-up conditions. The effect of DO on nitrite build-up was studied in 2 l lab-scale SBRs at DO 2.5 mg/l and 1.0 mg/l. The ammonium oxidizer was not inhibited at DO 2.5 mg/l and DO 1.0 mg/l, while nitrite oxidizer was inhibited at DO 1.0 mg/l. That results showed that nitrite oxidation rate of DO 1.0 mg/l was 16% lower than that of DO 2.5 mg/l. To certify the optimum aeration condition for nitrite build-up, experiments were conducted by changing aeration time at DO 1.0 mg/l. The optimum condition for nitritation was 2 cycles per day of 2 hr aeration-9 hr anoxic condition, at which influent ammonium ion (NH4+) was removed 99.9% and 82% of the removed nitrogen was converted to nitrite. However, 50% of the influent ammonium ion was removed and 95 % of the removed nitrogen was accumulated as nitrite at 1 cycle per day of 3 hr aeration-19 hr anoxic condition.