Table 1.
Empirical conditions for the Central Composite Design/Response Surface Methodology (CCD/RSM) and results (∑Cu,Cd,Zn (mg/L)) for real galvanic wastewater.
| Run | Experimental Conditions | Experimental Results * | ||
|---|---|---|---|---|
| pH | Na2CS3 (mg) | Time (min) | ∑Cu,Cd,Zn (mg/L) | |
| 1 | 8.0 | 300 | 10 | 2.99 ± 0.30 |
| 2 | 8.0 | 300 | 30 | 2.79 ± 0.28 |
| 3 | 8.0 | 500 | 10 | 1.85 ± 0.19 |
| 4 | 8.0 | 500 | 30 | 1.70 ± 0.17 |
| 5 | 10.0 | 300 | 10 | 0.94 ± 0.09 |
| 6 | 10.0 | 300 | 30 | 0.90 ± 0.09 |
| 7 | 10.0 | 500 | 10 | 0.68 ± 0.07 |
| 8 | 10.0 | 500 | 30 | 0.57 ± 0.06 |
| 9 | 7.3 | 400 | 20 | 3.20 ± 0.32 |
| 10 | 10.7 | 400 | 20 | 0.80 ± 0.08 |
| 11 | 9.0 | 232 | 20 | 0.84 ± 0.08 |
| 12 | 9.0 | 568 | 20 | 0.67 ± 0.07 |
| 13 | 9.0 | 400 | 3 | 0.74 ± 0.07 |
| 14 | 9.0 | 400 | 37 | 0.72 ± 0.07 |
| 15 (C) ** | 9.0 | 400 | 20 | 0.75 ± 0.08 |
| 16 (C) ** | 9.0 | 400 | 20 | 0.76 ± 0.08 |
* Parameter value ± the measurement uncertainty for an extension factor k = 2; ** center of the plan.