Table 2.

Central composite design matrix of orthogonal values with observed responses on bioflocculation efficiency.

Run	X 1	X 2	X 3	X 4	X 5	Bioflocculation efficiency (%)
						Experimental value	Predicted value
1	35	9	8	0.2	0.02	93.43	94.36
2	25	7	8	0.4	0.02	85.39	81.56
3	35	7	8	0.2	0.04	92.79	89.16
4	35	9	4	0.4	0.04	91.33	94.46
5	35	7	4	0.2	0.04	88.78	87.55
6	25	7	8	0.4	0.04	80.00	82.51
7	35	7	8	0.4	0.02	83.81	86.53
8	35	7	4	0.2	0.02	79.33	82.25
9	30	8	6	0.5	0.03	94.02	92.80
10	30	8	6	0.3	0.03	95.43	95.00
11	30	8	2	0.3	0.03	83.11	83.69
12	35	9	4	0.4	0.02	92.83	93.95
13	25	7	8	0.2	0.02	76.47	76.10
14	35	7	8	0.2	0.02	81.45	85.91
15	25	9	4	0.4	0.02	85.44	84.18
16	40	8	6	0.3	0.03	92.08	88.55
17	30	8	6	0.1	0.03	90.41	86.35
18	25	7	4	0.4	0.04	83.12	80.84
19	30	8	10	0.3	0.03	94.10	88.23
20	25	7	4	0.2	0.02	74.11	69.71
21	35	9	8	0.4	0.02	94.34	93.43
22	35	9	4	0.2	0.04	94.22	94.50
23	35	9	4	0.2	0.02	92.66	92.22
24	25	9	4	0.4	0.04	85.21	84.16
25	30	10	6	0.3	0.03	92.42	85.67
26	25	9	4	0.2	0.04	77.23	79.36
27	25	9	8	0.4	0.04	83.90	84.32
28	25	9	8	0.4	0.02	79.54	86.39
29	25	9	8	0.2	0.02	80.12	82.49
30	25	9	8	0.2	0.04	84.98	82.20
31	25	7	4	0.4	0.02	74.48	77.84
32	35	7	4	0.4	0.04	88.79	89.07
33	35	7	4	0.4	0.02	86.90	85.55
34	25	7	4	0.2	0.04	73.02	74.48
35	35	9	8	0.2	0.04	87.65	94.59
36	25	7	8	0.2	0.04	73.75	78.82
37	30	6	6	0.3	0.03	70.19	71.66
38	20	8	6	0.3	0.03	66.39	64.64
39	30	8	6	0.3	0.05	92.49	90.62
40	25	9	4	0.2	0.02	72.99	77.61
41	35	7	8	0.4	0.04	88.53	88.01
42	30	8	6	0.3	0.01	90.20	86.78
43	35	9	8	0.4	0.04	89.52	91.89