Table 1. Kinetics Parameters of Cr(VI) Adsorption by PPy/MLS.

	pseudo-first order model			pseudo-second order model			intraparticle diffusion model
C0/(mg/L)	K1	Qe	R2	K2	Qe	R2	Kip	C	R2
25	16.1 × 10–3	152.48	0.625	3.12 × 10–4	172.41	0.997	10.185	160.84	0.774
50	7.21 × 10–3	182.20	0.964	1.70 × 10–4	323.62	0.997	9.617	119.35	0.833
75	9.74 × 10–3	200.28	0.925	2.10 × 10–4	371.75	0.998	6.146	44.60	0.893