Table 2 Fractional factorial design for optimization of adsorption and results analysis
| Ligand type | Ligand conc. (µg/ml) | CBE conc. (EU/ml) | pH of incubation | Temp of incubation (°C) | Time of incubation (min) | %Removal |
|---|---|---|---|---|---|---|
| HIS | 275 | 500,000 | 6.5 | 25 | 17.5 | 71.90 |
| PMB | 275 | 500,000 | 6.5 | 25 | 17.5 | 51.24 |
| HIS | 500 | 250,000 | 9 | 2–8 | 5 | 67.68 |
| PMB | 275 | 500,000 | 6.5 | 2–8 | 17.5 | 24.79 |
| HIS | 50 | 750,000 | 4 | 25 | 5 | 67.35 |
| HIS | 500 | 750,000 | 9 | 25 | 30 | 40.30 |
| PMB | 500 | 250,000 | 4 | 25 | 5 | 56.25 |
| HIS | 50 | 250,000 | 4 | 2–8 | 30 | 62.50 |
| PMB | 50 | 750,000 | 9 | 2–8 | 5 | 54.76 |
| HIS | 275 | 500,000 | 6.5 | 2–8 | 17.5 | 85.12 |
| PMB | 500 | 750,000 | 4 | 2–8 | 30 | 43.88 |
| PMB | 50 | 250,000 | 9 | 25 | 30 | 65.85 |