S. No. | Factors | Units | Levels of study | ||
−1 | 0 | +1 | |||
1 | Flow | mL/min | 0.8 | 1.0 | 1.2 |
2 | Temp | ˚C | 25 | 30 | 35 |
3 | pH | - | 4.3 | 4.5 | 4.7 |