Table 2.
Physical characteristics of spent and unspent liquors at the artisanal tannery.
| Parameter | Liming | Deliming/Bating | Spent vegetable tanning | Spent alum tawing | Spent red dye | Black dye | Ghana EPA (2016) |
|---|---|---|---|---|---|---|---|
| Temperature (oC) | 33.22 ± 2.45 | 33.22 ± 0.83 | 32.40 ± 1.01 | 33.60 ± 1.15 | 33.50 ± 1.08 | 30.80 ± 0.56 | <3o above ambient |
| Colour (PtCo) | 48983 ± 634.11 | 17566 ± 679.54 | 22033 ± 1350.5 | 950.35 ± 123.3 | 53900 ± 804.65 | 16886 ± 900.9 | 100 |
| EC (μS/cm) | 56600 ± 26.28 | 34700 ± 21.50 | 10080 ± 77.55 | 52370 ± 3.42 | 8170 ± 4.30 | 6930 ± 1.32 | 1500 |
| TDS (mg/L) | 28500 ± 497.80 | 17533 ± 580.60 | 4996.7 ± 383.78 | 26166 ± 261.63 | 4123.3 ± 173.62 | 3576.7 ± 108.62 | 1000 |
| TSS (mg/L) | 6728.7 ± 645.42 | 8116.8 ± 633.88 | 3216.4 ± 868.78 | 1033.5 ± 704.65 | 1894.1 ± 385.01 | 2820 ± 165.82 | 50 |
| Turbidity (NTU) | 2953.4 ± 279.24 | 1733.3 ± 394.98 | 1805 ± 142.93 | 450.24 ± 43.98 | 1700 ± 186.6 | 943.50 ± 74.52 | 75 |