Optimization of phenol adsorption from synthetic wastewater by synthesized BiFeO3 perovskite material, using split-plot central composite design

Bulletin of the National Research Centre

Table 2 Independent variables, their levels, and responses using split-plot CCD

Run order	Whole plot	a: pH	B: Time (min)	C: Dosage (g)	Phenol removal (Y_P%)
1	1	7	165	0.6	89.09
2		7	165	0.6	89.04
3		7	165	0.6	89.04
4	2	12	165	0.6	87.22
5		12	165	0.6	87.25
6	3	7	165	0.6	88.85
7		7	165	0.6	88.88
8		7	165	0.6	88.95
9	4	4	87	0.8	81.29
10		4	243	0.8	66.55
11		4	243	0.4	67.56
12		4	87	0.4	88.63
13	5	7	165	0.6	88.85
14		7	165	0.6	88.95
15		7	165	0.6	88.95
16	6	10	87	0.4	88.95
17		10	87	0.8	75.45
18		10	243	0.4	89.21
19		10	243	0.8	89.00
20	7	2	165	0.6	68.54
21		2	165	0.6	69.11
22	8	7	165	0.2	87.92
23		7	165	1.0	83.95
24		7	300	0.6	75.49
25		7	30	0.6	80.96