Column Adsorption Studies for the Removal of Cr(VI) Ions by Ethylamine Modified Chitosan Carbonized Rice Husk Composite Beads with Modelling and Optimization

Table 1

Variables and levels considered for the adsorption of Cr(VI) using EAM-CCRCBs by CCD.

Factors		Range and levels (coded)
		−𝛼	−1	0	+1	+𝛼
Adsorbent dosage (g)	𝐴	0.05	0.09	0.13	0.16	0.2
pH	𝐵	2	3	4	5	6
Initial concentration (mg/L)	𝐶	100	200	300	400	500