Removal of Pb (II) from Synthetic Solution and Paint Industry Wastewater Using Activated Carbon Derived from African Arrowroot (Canna indica) Stem

Table 1

Coded and real values of operational parameters for the Box–Behnken statistical design.

Factors	Levels of Box–Behnken
	Low (−1)	Middle (0)	High (+1)
pH (x1)	3	5.5	8
Adsorbent dose (x2)	0.5	1	1.5
Initial concentration (x3)	50	100	150