Removal of Zinc from Aqueous Solution by Optimized Oil Palm Empty Fruit Bunches Biochar as Low Cost Adsorbent

Table 2

Design matrix with results.

Run	Point type	() HTT (°C)	() HR (°C/min)	() RT (min)	Yield (%)	(mg/g)
1	Center	550.00	10.00	105.00	26.14	13.72
2	Axial	550.00	15.00	105.00	25.2	11.43
3	Fact	460.81	7.03	60.40	32.08	10.28
4	Center	550.00	10.00	105.00	25.97	13.91
5	Axial	550.00	10.00	180.00	24.93	12.11
6	Axial	550.00	10.00	30.00	26.67	9.47
7	Axial	700.00	10.00	105.00	24.67	13.67
8	Fact	639.19	7.03	149.60	26.01	14.74
9	Axial	400.00	10.00	105.00	33.73	7.59
10	Fact	460.81	12.97	149.60	26.45	9.89
11	Axial	550.00	5.00	105.00	28.06	13.01
12	Center	550.00	10.00	105.00	26.25	14.22
13	Fact	460.81	12.97	60.40	28.54	8.35
14	Fact	460.81	7.03	149.60	30.52	11.53
15	Center	550.00	10.00	105.00	25.88	14.13
16	Center	550.00	10.00	105.00	25.9	13.81
17	Fact	639.19	7.03	60.40	26.29	12.22
18	Fact	639.19	12.97	149.60	23.2	13.37
19	Center	550.00	10.00	105.00	25.3	14.36
20	Fact	639.19	12.97	60.40	24.71	10.86