• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.3
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• pp.165-169
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• 2008

It has been reported that most wastewater treatment plants have difficulties in nitrogen removal during winter season due to declined activity of nitrifiers in the condition of low temperature. This study was conducted in order to find out optimum operating condition for efficient nitrogen removal in low temperature. A series of operating conditions with various HRTs of each tank were simulated using the GPS-X program. The optimum HRT combination for effective nitrogen removal was 0.3 hr/0.5 hr/1.36 hr/4.84 hr(PreAx/An/Ax/Ox) with 51.4% of T-N removal efficiency and 57.3% of $NH_4^+$-N removal efficiency.