Table 8.
The test design table and results of response surface method analysis.
| Number | Time (min) | Solid–Liquid Ratio (mL/mg) | pH | Temperature (°C) | Adsorption Capacity (mg/g) |
|---|---|---|---|---|---|
| 1 | 0 | 0 | 0 | 0 | 452 |
| 2 | 1 | 0 | 0 | −1 | 388 |
| 3 | 0 | −1 | −1 | 0 | 472 |
| 4 | 0 | 1 | 1 | 0 | 385 |
| 5 | −1 | 0 | −1 | 0 | 413 |
| 6 | 0 | 0 | −1 | 1 | 538 |
| 7 | 0 | −1 | 0 | 1 | 546 |
| 8 | −1 | 0 | 0 | −1 | 346 |
| 9 | 1 | 0 | 0 | 1 | 533 |
| 10 | 0 | 1 | 0 | 1 | 458 |
| 11 | 0 | 0 | 1 | −1 | 389 |
| 12 | 0 | 0 | 0 | 0 | 446 |
| 13 | −1 | 0 | 1 | 0 | 414 |
| 14 | 0 | −1 | 0 | −1 | 406 |
| 15 | 0 | 0 | 0 | 0 | 457 |
| 16 | 0 | −1 | 1 | 0 | 476 |
| 17 | −1 | −1 | 0 | 0 | 432 |
| 18 | 0 | 1 | 0 | −1 | 316 |
| 19 | 1 | 0 | 1 | 0 | 467 |
| 20 | 0 | 0 | −1 | −1 | 385 |
| 21 | −1 | 0 | 0 | 1 | 484 |
| 22 | 0 | 0 | 0 | 0 | 456 |
| 23 | 1 | 0 | −1 | 0 | 464 |
| 24 | 0 | 1 | −1 | 0 | 386 |
| 25 | −1 | 1 | 0 | 0 | 343 |
| 26 | 1 | 1 | 0 | 0 | 395 |
| 27 | 0 | 0 | 0 | 0 | 453 |
| 28 | 1 | −1 | 0 | 0 | 482 |
| 29 | 0 | 0 | 1 | 1 | 536 |