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

Table 6

Analysis of variance (ANOVA) for response surface quadratic model for adsorption capacity of Cr(VI) using EAM-CCRCBs.

Source	Sum of squares	Df	Mean square	𝐹 value	𝑃 value	Comments
Model	4175.38	9	463.9	109.79	<0.0001	Significant
𝐴	1134.68	1	1134.68	268.52	<0.0001
𝐵	222.9	1	222.9	52.75	<0.0001
𝐶	2537.14	1	2537.14	600.40	<0.0001
𝐴𝐵	24.01	1	24.01	5.68	0.0384
𝐴𝐶	0.34	1	0.34	0.082	0.7811
𝐵𝐶	9.07	1	9.07	2.15	0.1735
𝐴^2	11.04	1	11.04	2.61	0.1372
𝐵^2	66.19	1	66.19	15.66	0.0027
𝐶^2	163.49	1	163.49	38.69	<0.0001
Residual	42.26	10	4.23
Lack of fit	42.05	5	8.41	201.83	<0.0001
Pure error	0.21	5	0.042
Cor total	4217.64	19