Table 1.

Kinetic model parameters of As (V) sorption on ZVI products.

Kinetic Model	Kinetic Parameters	Linear		Non-Linear *
		nZVI-Bare	nZVI-Bento	nZVI-Bare	nZVI-Bento
Pseudo-first-order	qe exp (mg g−1)	19.9	19.8	19.9	19.8
	qe (mg g−1)	10.4 ± 1.3	10.9 ± 0.69	18.7 ± 0.59	18.3 ± 0.89
	K1 (min−1)	0.004 ± 0.001	0.004 ± 0.0004	0.012 ± 0.002	0.013 ± 0.003
	R2	0.83	0.91	0.97	0.94
Pseudo-second-order	qe exp (mg g−1)	19.9	19.8	19.9	19.8
	qe (mg g−1)	20.5 ± 0.09	21.0 ± 0.42	20.3 ± 0.33	20.0 ± 0.72
	K2 (min−1)	157.5 ± 17.7	95.2 ± 21.5	0.001 ± 0.0001	0.0001 ± 0.0002
	R2	0.99	0.99	0.99	0.97
	Rw	1.4 × 10−7	2.3 × 10−7	0.02	0.18
Elovich model	a (mg g−1 min−1)	2.68 ± 0.34	1.72 ± 0.11	1.00 ± 0.32	0.65 ± 0.18
	b (g mg−1)	0.32 ± 0.003	0.32 ± 0.003	0.29 ± 0.03	0.26 ± 0.03
	R2	0.96	0.97	0.96	0.97
Intra-particle diffusion model	Kint (mg g−1 min−0.5)	0.43 ± 0.005	0.44 ± 0.008	0.43 ± 0.08	0.44 ± 0.07
	Cint (mg g−1)	4.69 ± 0.18	4.18 ± 0.48	4.69 ± 1.63	3.91 ± 1.49
	R2	0.76	0.80	0.76	0.80

* Data represent mean ± SE.