TABLE 3.
Mean effluent concentrations of nitrogen species during aeration cycles
| Reactor | ANA (h on:h off) | Mean effluent conc (mg liter−1)a
|
|||
|---|---|---|---|---|---|
| NH3-N | NO2-N | NO3-N | TKN | ||
| A | 1:1 | 22.8 (39.5) | 0.7 (0.7) | 14.9 (20.1) | 40.5 (45.4) |
| B | 1:3 | 22.0 (33.0) | 1.9 (1.8) | 10.3 (6.3) | 51.5 (41.9) |
| C | 0.5:1.5 | 31.9 (43.5) | 2.5 (2.4) | 22.7 (22.0) | 55.4 (50.8) |
| D | 0.5:2 | 23.7 (36.5) | 2.5 (2.3) | 16.9 (10.9) | 48.0 (43.6) |
| E | 1:4 | 23.9 (37.4) | 2.8 (4.6) | 15.7 (10.8) | 49.3 (45.2) |
| ANOVA P valueb | 0.721 | 0.003 | 0.004 | 0.597 | |
a
A total of at least 40 data points were used to calculate mean effluent concentrations. Standard deviations are in parentheses.
b
Single-factor ANOVA.