Table 2. Fitted parameter for sorption kinetics of Cd(ii) removal.

	Parameter	SBC	Fe@SBC	P@SBC	P–Fe@SBC
PFO	q e,exp (mg g−1)	40	45	47	49
	q e,cal (mg g−1)	19.571	18.579	11.700	11.263
	k 1 (1/min)	0.403 × 10−2	0.678 × 10−2	−0.435 × 10−2	0.395 × 10−2
	R 2	0.951	0.988	0.782	0.832
PSO	q e,cal (mg g−1)	41.051	45.935	47.596	49.579
	k 2 (g mg−1 min−1)	0.077 × 10−2	0.126 × 10−2	0.177 × 10−2	0.187 × 10−2
	R 2	0.999	0.999	0.999	0.999
IPD	K d1 (mg g−1 min−1/2)	1.806	0.821	0.607	0.115
	C 1	11.138	20.838	24.369	36.164
	R 1 2	0.991	0.996	0.978	0.987
	K d2 (mg g−1 min−1/2)	1.580	0.555	0.435	0.047
	C 2	19.866	33.398	38.046	43.666
	R 2 2	0.994	0.988	0.998	0.975
	K d3 (mg g−1 min−1/2)	1.171	0.286	0.035	0.008
	C 3	30.182	42.445	45.897	46.502
	R 3 2	0.937	0.938	0.958	0.990