Table 2. Effect of FNA on the phosphorus removal performance of O/A/O/EI and A/O/A/O reactorsa.
| Influent FNA (×10−3 mg HNO2-N/L) | O/A/O/EI reactor | A/O/A/O reactor | |||||||
|---|---|---|---|---|---|---|---|---|---|
| PHA-up/VFA (C-mol/C-mol) | Gly-syn/VFA (mM-C/g VSS) | Effluent SOP (mg/L) | Idle SOP release (mg/L) | Anaerobic SOP release (mg/L) | Gly-de/VFA (C-mol/C-mol) | PHA-up/VFA (C-mol/C-mol) | Gly-syn (C-mol/g VSS) | Effluent SOP (mg/L) | |
| 0 | 0.52 ± 0.03 | 0.51 ± 0.04 | 0.22 ± 0.03 | 6.89 ± 0.04 | 62 ± 0.7 | 0.62 ± 0.04 | 1.19 ± 0.02 | 1.87 ± 0.09 | 0.75 ± 0.05 |
| 0.05 | 0.48 ± 0.05 | 0.49 ± 0.05 | 0.39 ± 0.05 | 6.22 ± 0.06 | 58 ± 1.2 | 0.61 ± 0.03 | 1.06 ± 0.05 | 1.72 ± 0.05 | 1.04 ± 0.07 |
| 0.15 | 0.42 ± 0.02 | 0.47 ± 0.08 | 1.15 ± 0.07 | 5.79 ± 0.03 | 53 ± 0.9 | 0.59 ± 0.05 | 1.01 ± 0.04 | 1.59 ± 0.07 | 3.85 ± 0.09 |
| 0.26 | 0.38 ± 0.05 | 0.41 ± 0.04 | 1.55 ± 0.11 | 5.42 ± 0.06 | 49 ± 0.8 | 0.55 ± 0.02 | 0.92 ± 0.06 | 1.36 ± 0.04 | 4.05 ± 0.11 |
| 0.38 | 0.35 ± 0.06 | 0.40 ± 0.02 | 2.36 ± 0.05 | 5.18 ± 0.02 | 43 ± 1.4 | 0.54 ± 0.03 | 0.79 ± 0.07 | 1.24 ± 0.06 | 5.12 ± 0.12 |
| 0.51 | 0.31 ± 0.03 | 0.38 ± 0.03 | 5.10 ± 0.08 | 4.87 ± 0.05 | 35 ± 0.5 | 0.53 ± 0.04 | 0.71 ± 0.05 | 1.12 ± 0.07 | 7.05 ± 0.09 |
aResults are the average and standard deviation, and the data were obtained during the steady-state operation.