Table 2 Removal of physicochemical and biological parameters of primary treated sewage through constructed wetlands (CW 1, CW 2 and CW 3)
Parameters (in mg L− 1 unless specified) | CW 1 | CW 2 | CW 3 | ||||||
|---|---|---|---|---|---|---|---|---|---|
0 h (influent) | 48 h (effluent) | Removal (%) | 0 h Influent) | 48 h (effluent) | Removal (%) | 0 h (influent) | 48 h (effluent) | Removal (%) | |
TDS | 547 | 270 | 50 | 566 | 268 | 52 | 565 | 260 | 54 |
TSS | 458 | 321 | 30 | 460 | 309 | 32 | 467 | 220 | 53 |
BOD | 376 | 152 | 59 | 375 | 147 | 61 | 368 | 76 | 79 |
COD | 473 | 223 | 53 | 483 | 202 | 58 | 486 | 109 | 77 |
NO3--N | 35.2 | 16.8 | 52.3 | 43.4 | 15.6 | 64. | 33.0 | 6 | 79.3 |
NH4+ | 36.5 | 17.7 | 51.5 | 38.6 | 15.3 | 60.3 | 36.5 | 7.5 | 79.4 |
PO4−−− | 15.8 | 5.6 | 64 | 12 | 4 | 61 | 13 | 2.9 | 78 |
Total coliform (CFU 100 mL−1) | 3 × 106 | 1.8 × 106 | 39 | 2.9 × 106 | 1.7 × 106 | 41 | 3.1 × 106 | 1.1 × 106 | 64 |
Fecal coliform (CFU 100 mL−1) | 2 × 105 | 1.4 × 105 | 30 | 1.8 × 105 | 0.9 × 105 | 50 | 1.6 × 105 | 0.6 × 105 | 61 |
E. coli (CFU 100 mL− 1) | 3 × 104 | 1.95 × 104 | 35 | 2.9 × 104 | 1.6 × 104 | 45 | 3.1 × 104 | 1.5 × 104 | 52 |