| Catalyst (ZnO/Nb2O5) in mg | ksec−1 | Effect of pH | COD in mg/l | ||
| Before degradation | After degradation | Before degradation | After degradation | ||
| 3.0 | 4.51 × 105 | 7.72 | 6.51 | 710 | 32 |
| 4.0 | 7.63 × 105 | 7.75 | 6.72 | 710 | 16 |
| 6.0 | 10.4 × 105 | 7.80 | 6.83 | 710 | 32 |
| 7.0 | 11.1 × 105 | 7.85 | 6.95 | 710 | 16 |