활성슬러지 모델을 이용한 A2O공법 영양염류 제거 및 미생물 거동

Abstract

In this study, simulation results of nitrogen and phosphorus removals and microbial activities for an A2O process in wastewater treatment plant are presented by using Activated Sludge Models (ASMs). Simulations were performed using pre-calibrated model and layout implemented in GPS-X simulation software. The models were used to investigate variations of SRT, water temperature, DO and C/N ratio effect on nutrients removal and microbial activity. According to the simulated results, the successful nitrification required SRT higher than 10.3 days, whereas increase of NO3-N loading in the anaerobic reactor caused phosphorus release by PAOs; the effluent NH4-N showed rapid change between 12 ℃(21.7 mg/L) and 13 ℃(3.2 mg/L); the effluent phosphorus was increased up to 1.9 mg/L at water temperature of 25 ℃; the DO increase was positive for heterotrophs and autotrophs growths but negative for PAOs growth; the PAOs showed low activity when C/N ratio was lower than 2.5. The experimental results indicated that the calibrated models can assure the prediction quality of the ASMs and can be used to optimize the A2O process.