Table 1.
Characterization of tannery effluents compared to Tunisian standards for discharges in public canalizations. Values given represent the mean of three replicates.
| Parameters (Unit) | Unhairing | Final | NT 106.002 |
|---|---|---|---|
| (UE) | (FE) | ||
| pH | 12.13 ± 0.34 | 11.64 ± 0.53 | 6.5 – 9 |
| EC (mS/cm) | 17.41 ± 0.41 | 18.2 ± 0.51 | — |
| Salt (g/L) | 14.8 ± 0.35 | 15.47 ± 0.43 | — |
| COD(g/L) | 25 ± 2.46 | 7.2 ± 1.09 | 1 |
| BOD5 (g/L) | 2.5 ± 0.68 | 1.25 ± 0.38 | 0.4 |
| BOD5/COD | 0.1 ± 0.02 | 0.17 ± 0.02 | — |
| TS (g/L) | 35.1 ± 1.95 | 20 ± 1.34 | — |
| TV (g/L) | 18.9 ± 1.59 | 4.9 ± 0.7 | — |
| TSS (g/L) | 10.9 ± 0.98 | 3.37 ± 0.83 | 0.4 |
| VSS (g/L) | 6.1 ± 1.40 | 2.2 ± 0.64 | — |
| TKN (mg/L) | 2632 ± 29.1 | 448 ±15.34 | 100 |
| NH4+- N (mg/L) | 572.6 ±19.53 | 259 ±26.67 | 100 |
| H2S (mg/L) | 1020 ±21.45 | 720 ±24.34 | — |
| Soluble protein (g/L) | 8.35 ± 0.72 | 0.059 ± 0.03 | — |
| Fat (%) | 6.62 ± 1.16 | 1.55 ± 0.34 | — |
| K (mg/L) | 8 ± 0.49 | 194 ±2.33 | 50 |
| Cr (mg/L) | << 0.1 | 7.02 ± 0.76 | 0.1 |
| Cd (mg/L) | 0.018 ± 0.01 | 0.048 ± 0.01 | 0.1 |
| Fe (mg/L) | 1.046 ± 0.45 | 1.618 ± 0.23 | 0.05 |
Number of samples for each parameter “n” = 3