Waste Foundry Sand as Permeable and Low Permeable Barrier for Restriction of the Propagation of Lead and Nickel Ions in Groundwater

Table 2

Constants of isotherm models with statistical measures for sorption of Pb⁺² and Ni⁺² ions onto WFS (time = 60 min, pH = 4 (Pb⁺²) and 6 (Ni⁺²), dosage = 2.5 g/100 mL, and agitation speed = 250 rpm).

Isotherm model	Parameter	Value
		Pb^+2	Ni^+2
Freundlich	KF (mg/g) (L/mg)^1/n	4.248	1.023
	1/n	0.537	0.288
	R^2	0.9276	0.9846
Langmuir	b (L/mg)	0.647	0.099
	qmax (mg/g)	13.966	4.227
	R^2	0.9983	0.9916