Table 2.

Box-Benkhen design of the independent variables and experimental values of LLPs yield (Y).

No.	Factor				Y (LLPs yield)/%
	X1-E/S ratio/(U/g)	X2-pH value	X3-ultrasonic times/min	X4-ultrasonic temperature)/°C
1	700	4.00	30.00	50.00	11.05
2	2,100	4.00	30.00	50.00	11.88
3	700	6.00	30.00	50.00	12.91
4	2,100	6.00	30.00	50.00	11.50
5	1,400	5.00	20.00	40.00	10.27
6	1,400	5.00	40.00	40.00	9.69
7	1,400	5.00	20.00	60.00	10.61
8	1,400	5.00	40.00	60.00	10.10
9	700	5.00	30.00	40.00	11.76
10	2,100	5.00	30.00	40.00	10.28
11	700	5.00	30.00	60.00	11.31
12	2,100	5.00	30.00	60.00	11.56
13	1,400	4.00	20.00	50.00	10.88
14	1,400	6.00	20.00	50.00	11.24
15	1,400	4.00	40.00	50.00	9.38
16	1,400	6.00	40.00	50.00	11.62
17	700	5.00	20.00	50.00	12.87
18	2,100	5.00	20.00	50.00	9.98
19	700	5.00	40.00	50.00	9.28
20	2,100	5.00	40.00	50.00	12.39
21	1,400	4.00	30.00	40.00	9.89
22	1,400	6.00	30.00	40.00	11.48
23	1,400	4.00	30.00	60.00	10.95
24	1,400	6.00	30.00	60.00	11.49
25	1,400	5.00	30.00	50.00	14.75
26	1,400	5.00	30.00	50.00	13.97
27	1,400	5.00	30.00	50.00	14.18
28	1,400	5.00	30.00	50.00	14.64
29	1,400	5.00	30.00	50.00	14.43