Halloysite@polydopamine/ZIF-8 Nanocomposites for Efficient Removal of Heavy Metal Ions

Table 1

Kinetic parameters of pseudo-first-order and pseudo-second-order models.

Heavy metals	Qeexp(mg/g)	Pseudo-first-order			Pseudo-second-order
		Qecal(mg/g)	k1 (min^−1)	R^2	Qecal(mg/g)	k2 (g·mg^−1·min^−1)	R^2
Cu^2+	156.75	122.97	0.01520	0.9309	226.76	0.00015	0.99067
Pb^2+	247.03	3.64	0.00930	0.6863	246.92	0.00932	0.99999
Ni^2+	81.70	65.35	0.01193	0.9730	91.83	0.00019	0.99436
Cd^2+	127.5	52.60	0.01601	0.9349	132.98	0.00042	0.99673