Table 2 Physical and chemical characteristics of the untreated and treated effluent
Parameters | Untreated effluent | Treated at pH 3 |
|---|---|---|
Physical parameters | ||
 Colour | Blackish colour | Colourless |
 Odour | Disagreeable smell | Odourless |
Chemical parameters | ||
 Electrical conductivity (mS/cm) | 27.3 | 16.6 |
 Biochemical oxygen demand (BOD) (mg/l) | 1250 | 380 |
 Chemical oxygen demand (COD) (mg/l) | 4210 | 1320 |
 Total dissolved solids (TDS) (mg/l) | 15,900 | 9800 |
 Total solids (TS) (mg/l) | 31,740 | 10,800 |
 Total hardness (TH) (mg/l) | 923 | 16 |
 Salinity (mg/l) | 16,200 | 9360 |
 Turbidity (NTU) | 453 | 18 |
 Sodium (mg/l) | 5000 | 2900 |
 Chromium (Cr) (mg/l) | 1055 | 23.05 |
 Lead (Pb) (mg/l) | 0.43 | 0.34 |