Table 2. ANOVA data of the RSM quadratic model for Cd2+ removal by DSC biosorbent.
| Model term | Sum of squares | df | Mean squares | F -value |
p-
value
Prob. >F |
|---|---|---|---|---|---|
| Model | 440.45 | 6 | 73.41 | 12.42 | 0.0011 |
| A-pH | 10.59 | 1 | 10.59 | 1.79 | 0.2175 |
| B-metal conc. | 36.88 | 1 | 36.88 | 6.24 | 0.0371 |
| C-Algal dose | 110.97 | 1 | 110.97 | 18.78 | 0.0025 |
| BC | 106.78 | 1 | 106.78 | 18.07 | 0.0028 |
| A2 | 36.33 | 1 | 36.33 | 6.15 | 0.0382 |
| C2 | 148.50 | 1 | 148.50 | 25.13 | 0.0010 |
| Residual | 47.28 | 8 | 5.91 | – | – |
| Lack of fit | 40.33 | 6 | 6.72 | 1.94 | 0.3791 |
| Pure error | 6.95 | 2 | 3.47 | – | – |
| Correlation total | 487.73 | 14 | – | – | – |
| R2 = 0.90 | Adj. R2= 0.83 | Pred. R2=0.62 | Adequate precision = 10.71 | Variation coefficient % = 2.59 | Mean = 93.8 |