Copper-Doped Zinc Oxide Nanoparticles: Synthesis, Characterization, and Application for Adsorptive Removal of Toxic Azo Dye

Table 2

Designed variables and the response using CCD.

Run	Time (min)	Dosage (g/L)	pH	Initial concentration (mg/L)	Response (% CR removal)
1	10	0.3	7	90	77.5
2	30	0.3	7	90	94.8
3	20	0.2	6	60	81.56
4	20	0.2	8	60	74.4
5	20	0.4	8	120	66.8
6	40	0.2	6	120	71.6
7	30	0.3	9	90	79.6
8	40	0.4	8	120	79.7
9	20	0.2	6	120	80.6
10	30	0.3	7	90	94.8
11	30	0.3	7	90	94.8
12	30	0.3	7	90	93.4
13	30	0.3	7	30	79.5
14	20	0.4	8	60	73.48
15	20	0.4	6	60	85.2
16	20	0.2	8	120	73.06
17	40	0.2	8	60	80.5
18	30	0.1	7	90	70.5
19	40	0.4	8	60	80.8
20	30	0.5	7	90	73.24
21	20	0.4	6	120	77.6
22	40	0.4	6	60	70.24
23	30	0.3	7	90	94.8
24	30	0.3	7	150	78.6
25	50	0.3	7	90	74.5
26	30	0.3	5	90	80.5
27	30	0.3	7	90	92.2
28	40	0.4	6	120	76.6
29	40	0.2	6	60	67.24
30	40	0.2	8	120	84.3