Table 1 The experimental range and levels of the control factors in the CCD.
From: Intensification of strontium (II) ion biosorption on Sargassum sp via response surface methodology
Variable | Low axial (− α) | Low factorial (− 1) | Center | High factorial (+ 1) | High axial (+ α) |
|---|---|---|---|---|---|
x1(A): Temperature (°C) | 15 | 23 | 30 | 38 | 45 |
x2(B): Initial strontium (II) concentration (mg/l) | 50 | 113 | 175 | 238 | 300 |
x3(C): Biomass dose (g/100 ml) | 0.1 | 0.2 | 0.3 | 0.4 | 0.5 |
x4(D): pH | 2.5 | 5.1 | 7.8 | 10.4 | 13 |
Level 1 | Level 2 | ||||
x5(E): Type of biosorbent | natural Sargassum sp. | Mg- pretreated Sargassum sp. |
