Table 1.
A comparison of TP and SRP concentrations in wastewater considering all eight monitoring stations (W1–sewage outflowing from WWTP and W2–W8–sewage after cleaning in particular zones of the Sequential Biofiltration System).
| Parameter | Station | Median | Mean concentration [mg dm−3] | N | S.D. |
|---|---|---|---|---|---|
| TP, p = 0.000* | W1 | 5.42 | 5.13 | 36 | 1.93 |
| W2 | 5.35 | 5.26 | 36 | 2.13 | |
| W3 | 5.29 | 5.11 | 36 | 1.82 | |
| W4 | 5.21 | 4.99 | 36 | 2.04 | |
| W5 | 4.91 | 4.71 | 36 | 1.91 | |
| W6 | 5.23 | 4.83 | 36 | 1.91 | |
| W7 | 4.85 | 4.73 | 36 | 2.12 | |
| W8 | 4.38 | 4.31 | 36 | 2.03 | |
| % Reduction of TP between W1–W8 | Mean | 16 | |||
| Max. | 93 | ||||
| Min. | −17 | ||||
| SRP, p = 0.000* | W1 | 5.31 | 5.44 | 36 | 2.68 |
| W2 | 4.89 | 5.20 | 36 | 2.69 | |
| W3 | 5.40 | 5.64 | 36 | 2.81 | |
| W4 | 4.56 | 4.97 | 36 | 2.71 | |
| W5 | 4..86 | 4.77 | 36 | 2.22 | |
| W6 | 4.65 | 4.57 | 36 | 2.46 | |
| W7 | 4.69 | 4.49 | 36 | 2.57 | |
| W8 | 3.87 | 4.10 | 36 | 2.56 | |
| % Reduction of SRP between W1–W8 | Mean | 25 | |||
| Max. | 93 | ||||
| Min. | −61 | ||||
Friedman ANOVA test (*significance at p < 0.05). Percentage reduction of TP and SRP concentrations between stations W1 and W8 in the study period. A minus sign in % Reduction indicates increased concentration in outflowing wastewater. Thirty-six samples were taken from each of eight stations (total number of analysed samples = 288).