Table 1.
Sediment physicochemical characteristicsa.
| Sediment | |||
|---|---|---|---|
| Ofin | Apapa | Eledu | |
| PAH (ug/kg) | |||
| Acenaphthene | 20 ± 0.6 | 38 ± 0.8 | 5 ± 0.6 |
| Acenaphthylene | 115 ± 0.5 | 150 ± 0.3 | 60 ± 0.2 |
| Anthracene | 28 ± 0.1 | 64 ± 0.1 | 19 ± 2.1 |
| Benzo(a)anthracene | 261 ± 0.4 | 376 ± 7.7 | 308 ± 11.2 |
| Benzo(a)pyrene | 84 ± 6.8 | 334 ± 8.5 | 80 ± 0.3 |
| Benzo(b)fluoranthene | 492 ± 12.3 | 787 ± 6.6 | 426 ± 0.5 |
| Benzo(g,h,i)perylene | 231 ± 1.9 | 270 ± 1.5 | 68.6 ± 4.5 |
| Benzo(k)fluoranthene | 149 ± 7.9 | 208 ± 0.3.7 | 118 ± 10.1 |
| Chrysene | 196 ± 9.9 | 210 ± 16.1 | 176 ± 2.2 |
| Dibenzo(a,h)anthracene | 29 ± 7.9 | 43 ± 7.9 | 26 ± 7.9 |
| Fluoranthene | 531 ± 1.1 | 829 ± 8.4 | 411 ± 7.7 |
| Fluorene | 26 ± 3.5 | 75 ± 8.1 | 5 ± 1.01 |
| Indeno(1,2,3-cd)pyrene | 294 ± 1.2 | 517 ± 3.8 | 122 ± 5.2 |
| Naphthalene | 29 ± 3.1 | 35 ± 1.1 | 20 ± 1.1 |
| Phenanthrene | 802 ± 15.9 | 986 ± 12.3 | 710 ± 6.5 |
| Pyrene | 688 ± 12.1 | 719 ± 7.2 | 457 ± 15.1 |
| Sum of all PAH | 3,947 | 5,606 | 2,991 |
| Heavy metals (mg/kg) | |||
| Cd | 4.82 ± 0.02 | 4.06 ± 0.01 | 3.02 ± 0.03 |
| Co | 4.17 ± 0.1 | 4.14 ± 0.1 | 2.46 ± 0.4 |
| Cr | 10.43 ± 0.03 | 13.16 ± 0.02 | 8.36 ± 0.06 |
| Cu | 15.63 ± 0.57 | 16.96 ± 0.01 | 14.86 ± 0.04 |
| Ni | 15.11 ± 0.02 | 16.39 ± 0.21 | 12.16 ± 0.02 |
| Pb | 0.13 ± 0.01 | 0.14 ± 0.05 | 0.13 ± 0.01 |
| Zn | 16.73 ± 0.45 | 17.06 ± 0.20 | 13.63 ± 0.30 |
| Sum of all metals | 67.02 | 71.90 | 54.62 |
| Other parameters | |||
| pH | 8.4 ± 0.18 | 7.2 ± 0.2 | 7.8 ± 0.1 |
| Total organic matter (g/kg) | 149 ± 1.1 | 342 ± 0.5 | 428 ± 3.3 |
| COD (mg/l) | 480 ± 0.02 | 218 ± 0.01 | 1274 ± 0.1 |
| SOD (mg/m2/d) | 4.02 ± 0.1 | 12.79 ± 0.1 | 20.48 ± 0.1 |
| Nitrate (mg/l) | 57.3 ± 0.2 | 63.3 ± 0.15 | 70 ± 0.06 |
| Total phosphate (mg/kg) | 1.0 ± 0.2 | 1.62 ± 0.06 | 0.4 ± 0.2 |
| Trichloroethyleneb | Negative | Negative | Positive |
| Fe (mg/kg) | 104.74 ± 0.57 | 143.74 ± 0.03 | 659.31 ± 0.09 |
aFor all measures, n = 3. Abbreviations: COD, Chemical oxygen demand. SOD, Sediment oxygen demand. bQualitative analysis.