NADH 센서를 이용한 생물학적 동시 탈질·질산화공정에서 질소, 인제거 영향인자 및 거동 평가

Evaluation of Affecting Factors and Trace on N and P removal in Biological SND(Simultaneous Nitrification and Denitrification) Process with NADH Sensor

In this study, the factors affecting on biological N and P removal using SND (simultaneous nitrification and denitrification) process were investigated and evaluated to find the possibility for treating N and P through SND with NADH by surveying N and P trace in aeration tank. The results on surveying the variation of NH₄+-N+NO₃−-N concentration in order to estimate the degree of SND in each point (P2, P3, P4, P5) of aeration tank showed that denitrification efficiency in P2 (front zone), nitrification and denitrification efficiencies in P4 (middle zone) were 67%, 86% and 39%, respectively. When it analyzed PO₄-³-P concentration in each point of aeration tank, PO₄-³-P concentration into P2 was 1.25 mg/L, increased to 2.22 mg/L by P release in P2 zone, decreased to 0.74 mg/L by P uptake in P4. Consequently, we could estimate which high P removal efficiency observed in this study was caused by biological phosphorus removal. To find the operating factors affecting effluent T-N, we analyzed the correlation among FN/M ratio, C/N ratio, Temp. and SRT etc and then the results showed that the correlation among FN/M ratio, C/N ratio and Temp was no high. However, in the relationship of SRT and other parameters (effluent NH₄+-N and effluent BOD), the short SRT could be affected on effluent NH₄+-N and so effluent BOD could be increased. Thus, SRT operation should be controlled over 10 days. The results for analyzing the correlation between SRT and influent NO₃--N in order to investigate the operating factors affecting effluent T-P showed that T-P or PO₄-³-P was no high correlation with SRT, whereas PO₄-³-P concentration increased along with increasing NO₃--N concentration into P2. Based on these results, we could obtain the conclusion which effluent PO₄-³-P concentration depend on NO₃--N concentration into P2 using regression analysis (R²=0.97). In this study, the factors affecting on biological N and P removal using SND (simultaneous nitrification and denitrification) process were investigated and evaluated to find the possibility for treating N and P through SND with NADH by surveying N and P trace in aeration tank. The results on surveying the variation of NH₄+-N+NO₃−-N concentration in order to estimate the degree of SND in each point (P2, P3, P4, P5) of aeration tank showed that denitrification efficiency in P2 (front zone), nitrification and denitrification efficiencies in P4 (middle zone) were 67%, 86% and 39%, respectively. When it analyzed PO₄-³-P concentration in each point of aeration tank, PO₄-³-P concentration into P2 was 1.25 mg/L, increased to 2.22 mg/L by P release in P2 zone, decreased to 0.74 mg/L by P uptake in P4. Consequently, we could estimate which high P removal efficiency observed in this study was caused by biological phosphorus removal. To find the operating factors affecting effluent T-N, we analyzed the correlation among FN/M ratio, C/N ratio, Temp. and SRT etc and then the results showed that the correlation among FN/M ratio, C/N ratio and Temp was no high. However, in the relationship of SRT and other parameters (effluent NH₄+-N and effluent BOD), the short SRT could be affected on effluent NH₄+-N and so effluent BOD could be increased. Thus, SRT operation should be controlled over 10 days. The results for analyzing the correlation between SRT and influent NO₃--N in order to investigate the operating factors affecting effluent T-P showed that T-P or PO₄-³-P was no high correlation with SRT, whereas PO₄-³-P concentration increased along with increasing NO₃--N concentration into P2. Based on these results, we could obtain the conclusion which effluent PO₄-³-P concentration depend on NO₃--N concentration into P2 using regression analysis (R²=0.97).