Oxidized Renewable Materials for the Removal of Cobalt(II) and Copper(II) from Aqueous Solution Using in Batch and Fixed-Bed Column Adsorption

Table 1

Independent variables evaluated in the 2² experimental design and their levels for Cu²⁺ and Co²⁺ adsorption in a fixed-bed column using SBox as adsorbent.

Independent variable	Level
	−1	0	+1
	0.47	0.86	1.26
	0.17	0.42	0.68
	0.70	1.05	1.40