Table 1 Codes and actual variables and their levels in BBD.
Independent variable | Codes | Unit | Levels | |||
|---|---|---|---|---|---|---|
-1 | 0 | + 1 | ||||
Adsorbent dose | A (x1) | g | 0.02 | 0.05 | 0.08 | |
pH | B (x2) | 4 | 7 | 10 | ||
Temperature | C (x2) | °C | 30 | 45 | 60 | |
Time | D (x4) | Min | 5 | 20 | 30 | |
Independent variable | Codes | Unit | Levels | |||
|---|---|---|---|---|---|---|
-1 | 0 | + 1 | ||||
Adsorbent dose | A (x1) | g | 0.02 | 0.05 | 0.08 | |
pH | B (x2) | 4 | 7 | 10 | ||
Temperature | C (x2) | °C | 30 | 45 | 60 | |
Time | D (x4) | Min | 5 | 20 | 30 | |
