Table 2.
Regression statistics and analysis of variance (ANOVA) for the experimental results of Plackett-Burman design used for cadmium removal by Ulva fasciata.
| Source | df | Coefficient | Effect | Contribution % | t -Stat | P-value | Confidence Level (%) |
|---|---|---|---|---|---|---|---|
| Model | 6 | 95.2992 | 493.355 | 0.00024 | 99.976 | ||
| Contact time (A) | 1 | −0.2975 | −0.595 | 5.879 | −1.540 | 0.184 | 81.60 |
| Cadmium conc. (B) | 1 | 3.2825 | 6.565 | 64.872 | 16.993 | 0.00001 | 100.00 |
| pH (C) | 1 | 0.5025 | 1.005 | 9.931 | 2.601 | 0.048 | 95.20 |
| Temperature (D) | 1 | 0.3342 | 0.6684 | 6.605 | 1.730 | 0.144 | 85.60 |
| Biomass (E) | 1 | 0.6275 | 1.255 | 12.401 | 3.249 | 0.023 | 97.70 |
| Agitation –Static (F) | 1 | 0.0158 | 0.0316 | 0.312 | 0.082 | 0.938 | 6.20 |
| df | SS | MS | F | ||||
| Regression | 6 | 139.458 | 23.243 | 51.910 | |||
| Residual Error | 5 | 2.239 | 0.448 | ||||
| Total | 11 | 141.697 | |||||
| R | 0.9921 | R2 (adj) | 0.9652 | ||||
| R2 | 0.9842 | R2 (pred) | 0.9090 |
*Significant values, df: Degree of freedom, F: Fishers’s function, P: Level of significance, PRESS 12.8953.