Table 3.

Test matrices of the full factorial design and the face-centered composite design.

	Factor 1	Factor 2	Factor 3	Factor 4	Responses
Test matrix of the full factorial design
N°	A:pH	B:Temperature (°C)	C: Contact time (h)	D:Starch (g/L)	PA-BPTAB (μg/L)
1	10	4	72	0	22.0
2	10	4	1	0	17.2
3	10	90	72	0	28.7
4	4	4	72	0	46.3
5	10	90	72	10	21.4
6	4	4	72	10	45.9
7	4	90	1	10	49.2
8	4	4	1	10	18.9
9	10	90	1	10	31.8
10	10	4	1	10	21.9
11	4	90	72	10	62.1
12	10	90	1	0	25.2
13	4	4	1	0	3.3
14	10	4	72	10	9.9
15	4	90	72	0	63.9
16	4	90	1	0	20.1
17	7	47	36.5	5	28.5
18	7	47	36.5	5	28.9
19	7	47	36.5	5	29.0
20	7	47	36.5	5	28.2
Test matrix of the face-centered composite design
N°	A: pH	B:Temperature (°C)	C: Contact time (h)		PA-BPTAB (μg/L)
1	7	47	36.5		9.3
2	7	47	72		29.6
3	7	90	36.5		25.2
4	4	4	72		14.5
5	4	90	1		31.7
6	10	4	72		23.9
7	4	90	72		60,8
8	4	47	36.5		15.0
9	7	4	36.5		1.3
10	7	47	36.5		9.3
11	10	47	36.5		15.5
12	7	47	1		8.5
13	10	90	72		60.5
14	10	90	1		20.4
15	4	4	1		10.4
16	7	47	36.5		9.1
17	10	4	1		8.4