Table 2.

Kinetic parameters of NRPA in the adsorption of CR.

	Co (mg L−1)	25	50	75	100	125	150	175	200
Pseudo-first order	Qe exp (mg g−1)	9.270	16.680	28.650	45.780	58.930	73.440	98.530	103.470
	Qe cal (mg g−1)	10.260	15.830	29.030	44.530	57.170	74.210	97.250	104.360
	k1 (min−1)	0.418	0.542	0.570	0.651	0.752	0.836	0.854	0.888
	R2	0.997	0.998	0.995	0.987	0.998	0.988	0.998	0.996
	%SSE	0.032	0.015	0.004	0.008	0.009	0.003	0.004	0.003
	RMSE	0.096	0.115	0.117	0.126	0.128	0.462	0.573	0.588
Pseudo-second order	Qe cal (mg g−1)	13.838	20.600	32.720	50.734	62.076	87.680	96.540	115.103
	k2 (g mg−1 min−1)	0.204	0.299	0.347	0.364	0.588	0.576	0.747	0.763
	R2	0.896	0.922	0.889	0.936	0.975	0.967	0.878	0.983
	%SSE	0.149	0.071	0.043	0.033	0.016	0.058	0.006	0.034
	RMSE	0.106	0.122	0.145	0.179	1.433	1.723	2.331	2.127
Elovich	α (mg (g min)−1)	0.166	0.196	0.254	0.772	0.939	1.208	1.475	1.643
	β (g mg−1)	0.115	0.172	0.208	0.278	0.569	0.643	0.669	0.865
	R2	0.988	0.986	0.989	0.996	0.996	0.988	0.991	0.997
Intra-particle diffusion	K1d (mg g−1 min−0.5)	0.219	0.370	0.558	0.763	1.454	1.705	2.359	4.563
	C1(mg g−1)	− 0.356	− 0.400	− 0.872	− 1.290	1.258	2.290	5.875	7.358
	R2	0.984	0.955	0.978	0.947	0.988	0.976	0.987	0.995