From: Removal of heavy metal chromium from tannery effluent using ultrafiltration membrane
Parameters | Raw effluent | Accepted limitsa |
---|---|---|
Physical parameters | ||
 Color | Blackish color | Colorless |
 Odor | Disagreeable smell | Odorless |
 pH | 7.43 | 6.5–8.5 |
Chemical parameters | ||
 Electrical conductivity (EC) (mS/cm) | 27.3 | 0.288 |
 Dissolved oxygen (DO) mg/l | 0.2 | 4–6 |
 Biochemical oxygen demand (BOD) mg/l | 2556 | 30 |
 Chemical oxygen demand (COD) mg/l | 6419 | 250 |
 Total dissolved solids (TDS) mg/l | 15,900 | 2100 |
 Total solids (TS) mg/l | 31,740 | 2200 |
 Total hardness (TH) mg/l | 923 | 300 |
 Salinity (mg/l) | 16,200 | Not mentioned |
 Turbidity (NTU) | 453 | 10 |
 Sodium (mg/l) | 5000 | 1000–1500 |
 Chromium (Cr) (mg/l) | 1055 | 2.0 |