Chemical Modifications of Cassava Peel as Adsorbent Material for Metals Ions from Wastewater

Table 1

CCRD planning matrix (coded and real rates).

Tests		Mass (mg)		pH
1	−1.00	396.39	−1.00	3.60
2	1.00	1103.61	−1.00	3.60
3	−1.00	396.39	1.00	6.40
4	1.00	1103.61	1.00	6.40
5	0.00	750.00	0.00	5.00
6	−1.41	250.00	0.00	5.00
7	0.00	750.00	1.41	7.00
8	1.41	1250.00	0.00	5.00
9	0.00	750.00	−1.41	3.00
10	0.00	750.00	0.00	5.00
11	0.00	750.00	0.00	5.00
12	0.00	750.00	0.00	5.00