Research Article
Optimization of Aqueous Two-Phase Systems for the Recovery of Soluble Proteins from Tannery Wastewater Using Response Surface Methodology
Table 1
Coded and uncoded values of factors of 25–1 fractional factorial design (fFD).
| Experiment no. | Codeda and uncodedb values of variables | Recovery (%) | PEG (% w/w) | SC (% w/w) | pH | NaCl (M) | Temperature (°C) |
| 1 | 12 (−1) | 23(+1) | 8 (+1) | 0.3 (+1) | 20 (−1) | 67.24 | 2 | 20 (+1) | 15 (−1) | 8 (+1) | 0.1 (−1) | 40 (+1) | 68.24 | 3 | 12 (−1) | 15 (−1) | 6 (−1) | 0.1 (−1) | 40 (+1) | 33.95 | 4 | 20 (+1) | 23 (+1) | 8 (+1) | 0.3 (+1) | 40 (+1) | 83.42 | 5 | 12 (−1) | 23 (+1) | 6 (−1) | 0.3 (+1) | 40 (+1) | 52.71 | 6 | 12 (−1) | 23 (+1) | 8 (+1) | 0.1 (−1) | 40 (+1) | 50.49 | 7 | 20 (+1) | 23 (+1) | 8 (+1) | 0.1 (−1) | 20 (−1) | 52.21 | 8 | 12 (−1) | 23 (+1) | 6 (−1) | 0.1 (−1) | 20 (−1) | 37.29 | 9 | 20 (+1) | 15 (−1) | 6 (−1) | 0.1 (−1) | 20 (−1) | 29.89 | 10 | 20 (+1) | 15 (−1) | 8 (+1) | 0.3 (+1) | 20 (−1) | 71.77 | 11 | 20 (+1) | 23 (+1) | 6 (−1) | 0.3 (+1) | 20 (−1) | 54.59 | 12 | 20 (+1) | 15 (−1) | 6 (−1) | 0.3 (+1) | 40 (+1) | 64.49 | 13 | 12 (−1) | 15 (−1) | 8 (+1) | 0.3 (+1) | 40 (+1) | 75.33 | 14 | 12 (−1) | 15 (−1) | 8 (+1) | 0.1 (−1) | 20 (−1) | 61.46 | 15 | 20 (+1) | 23 (+1) | 6 (−1) | 0.1 (−1) | 40 (+1) | 48.93 | 16 | 12 (−1) | 15 (−1) | 6 (−1) | 0.3 (+1) | 20 (−1) | 58.49 |
|
|
aData in brackets; bData without brackets.
|