Removal of Hexavalent Chromium by Using Sustainable Green Materials as Low-Cost Adsorbents

Table 6

Parameters of pseudo-first-order, pseudo-second-order, and Elovich models for Cr(VI) adsorption onto tea residues at different initial concentrations.

	Green tea residue	Pu-erh residue	Tieguanyin residue
(mg g^-1)	2.32	2.37	2.1
Pseudo-first-order
(mg g^-1)	2.08	2.32	1.99
(min^-1)
	0.8948	0.9787	0.9203
Pseudo-second-order
(mg g^-1)	2.42	2.53	2.26
(g mg^-1 min^-1)	1.05 × 10^-2	5.49 × 10^-2	1.52 × 10^-2
	0.9511	0.9836	0.9727
Elovich
(mg g^-1 min^-1)	0.11	3.03	0.17
(g mg^-1)	1.90	2.89	2.22
	0.9815	0.8271	0.9888