Table 5.
Analyses of variance analysis of Pb(II) removal.
| Source | Sum of Squares | Degree of Freedom | Mean Square | F-Value | p-Value | Status |
|---|---|---|---|---|---|---|
| Model | 4650.23 | 14 | 332.16 | 129.71 | <0.0001 | Significant |
| A:pH | 3072.00 | 1 | 3072.00 | 1199.64 | <0.0001 | |
| B: Adsorbent dose | 275.52 | 1 | 275.52 | 107.59 | <0.0001 | |
| C: Contact time | 0.0208 | 1 | 0.0208 | 112.36 | <0.0001 | |
| D: Temperature | 300.00 | 1 | 300.00 | 117.15 | <0.0001 | |
| A.B | 243.23 | 1 | 243.23 | 20.12 | 0.0021 | |
| A.C | 123.12 | 1 | 123.12 | 30.45 | 0.0034 | |
| A.D | 110.23 | 1 | 110.23 | 42.56 | 0.0043 | |
| B.C | 0.0625 | 1 | 0.0625 | 0.0244 | 0.8785 | |
| B.D | 4.00 | 1 | 4.00 | 10.56 | 0.0232 | |
| C.D | 0.0024 | 1 | 0.0024 | 0.0120 | 1.0000 | |
| A2 | 886.95 | 1 | 886.95 | 346.36 | 0.0523 | |
| B2 | 94.45 | 1 | 94.45 | 36.88 | 0.8412 | |
| C2 | 3.70 | 1 | 3.70 | 1.45 | 0.02523 | |
| D2 | 8.61 | 1 | 8.61 | 3.36 | 0.0916 | |
| Residual | 30.73 | 12 | 2.56 | - | - | |
| Lack of Fit | 30.73 | 10 | 3.07 | 4.52 | 0.86 | Not significant |
| Pure Error | 0.0024 | 2 | 0.0049 | - | - | |
| Cor Total | 4680.96 | 26 | - | - | - |
R2 = 0.99, R2adjusted = 0.98. Adequate Precision = 37.50.