Table 1 Summary of typical values of surface water quality in the study area
Parameters | Bac Duong (N = 384) | Bac Hung Hai (N = 395) | Overall (N = 779) |
|---|---|---|---|
BOD5 | |||
Mean (SD) | 28.8 (31.1) | 25.5 (19.1) | 27.1 (25.8) |
Median [Min, Max] | 19.8 [4.90, 294] | 21.5 [0, 183] | 20.4 [0, 294] |
COD | |||
Mean (SD) | 75.8 (85.6) | 64.1 (48.3) | 69.9 (69.4) |
Median [Min, Max] | 51.2 [9.60, 816] | 55.1 [0, 451] | 52.8 [0, 816] |
NH4 | |||
Mean (SD) | 4.77 (4.66) | 7.78 (8.96) | 6.29 (7.32) |
Median [Min, Max] | 3.42 [0.220, 35.5] | 4.31 [0, 46.8] | 3.86 [0, 46.8] |
PO4 | |||
Mean (SD) | 0.580 (1.04) | 0.589 (1.15) | 0.585 (1.09) |
Median [Min, Max] | 0.200 [0.010, 7.32] | 0.0600 [0, 8.24] | 0.140 [0, 8.24] |
Turbidity | |||
Mean (SD) | 36.2 (30.9) | 23.3 (13.6) | 29.6 (24.6) |
Median [Min, Max] | 31.1 [10.1, 383] | 21.2 [8.21, 99.0] | 23.3 [8.21, 383] |
TSS | |||
Mean (SD) | 45.6 (30.5) | 30.8 (16.5) | 38.1 (25.5) |
Median [Min, Max] | 37.7 [10.5, 409] | 26.6 [2.01, 133] | 32.5 [2.01, 409] |
Coliform | |||
Mean (SD) | 179,000 (1,260,000) | 865,000 (3,210,000) | 527,000 (2,470,000) |
Median [Min, Max] | 14,000 [200, 16000000] | 24,000 [0, 16000000] | 19,000 [0, 16000000] |
DO | |||
Mean (SD) | 3.46 (1.95) | 2.89 (1.56) | 3.17 (1.78) |
Median [Min, Max] | 3.30 [0.0100, 11.3] | 2.70 [0, 7.36] | 3.00 [0, 11.3] |
Water temperature | |||
Mean (SD) | 25.3 (4.82) | 24.4 (4.95) | 24.9 (4.90) |
Median [Min, Max] | 24.8 [16.2, 35.8] | 24.6 [0, 33.4] | 24.7 [0, 35.8] |
pH | |||
Mean (SD) | 7.32 (0.327) | 7.32 (0.505) | 7.32 (0.426) |
Median [Min, Max] | 7.30 [5.69, 8.70] | 7.33 [0, 8.68] | 7.30 [0, 8.70] |
WQI | |||
Mean (SD) | 24.1 (21.5) | 25.8 (24.7) | 25.0 (23.2) |
Median [Min, Max] | 12.6 [0, 80.8] | 13.4 [0.780, 87.5] | 12.9 [0, 87.5] |