| Sampling points | Before treatment (mg/l) | After treatment (mg/l) | Percentage reduction (%) | Average (%) |
| P1 | 31.27 | 6.29 | 79.88 | 82.26 |
| P2 | 36.64 | 6.81 | 81.41 | |
| P3 | 41.11 | 5.96 | 85.50 |