STS | Pond | Surface area (m2) | Hydraulic retention time (Days) | Effluent BOD (mg/l) | Effluent faecal coliforms (FC per 100 ml) |
Anaerobic pond | A | 2220 | 3 | 244 | 5,681,818 |
Facultative ponds | F1 | 3024 | 3 | 128 | 645,661 |
F2 | 3024 | 2.7 | 71 | 80,506 | |
Maturation ponds | M1 | 3024 | 2 | 44.4 | 12,985 |
M2 | 3360 | 2.2 | 26.7 | 1,932 | |
Constructed Wetland | VSF | 465 | 0.1 | 24.3 | 1674 |
HSSF | 1396 | 0.2 | 20 | 195 | |
TOTAL | 16,513 | 13.2 |
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