Effect of Physical and Chemical Activation on the Removal of Hexavalent Chromium Ions Using Palm Tree Branches

Table 3

Kinetic parameters for the adsorption of Cr(VI) onto different activated Palm tree branches.

Kinetic model		Adsorbents
		RPB	APBH 20	APBH 50	APBS	APBK
Pseudo-first-order	𝐾1 (min^−1)	0.013	0.015	0.062	0.013	0.017
	𝑞𝑒 (mg g^−1)	79.0	36.3	120	100	66.1
	𝑅^2	0.91	0.90	0.92	0.91	0.92
Pseudo-second-order	𝐾2 (g mg^−1 min^−1)	9.1 × 10^−5	2.9 × 10^−3	2.2 × 10^−4	1.3 × 10^−4	1.4 × 10^−3
	𝑞𝑒 (mg g^−1)	187	91.8	157	113	83.0
	𝑅^2	0.99	0.98	0.99	0.99	0.98
Intraparticle diffusion	𝐾𝑝 (mg g^−1 min^−1/2)	8.40	2.30	13.8	3.60	8.20
	𝑅^2	0.90	0.91	0.91	0.90	0.92