Functionalized Glutathione on Chitosan-Genipin Cross-Linked Beads Used for the Removal of Trace Metals from Water

Table 2

Parameters of Langmuir and Freundlich isotherms for the adsorption reaction of Fe(II) and Cu(II) onto CS-GG beads.

Metal ions	Langmuir
Temp.°K	Measured qmax mg·g^−1	KL L·mg^−1	qmax mg·g^−1	RL	R^2
Fe(II)	293	126.4	0.0046	208.33	0.666	0.975
	303	147.5	0.0071	212.77	0.530	0.988
	313	152.3	0.0055	243.90	0.578	0.981
Cu(II)	293	156.4	0.0070	217.39	0.526	0.977
	303	189.5	0.0076	263.15	0.522	0.995
	313	199.0	0.0072	277.77	0.520	0.974
	Freundlich
	Temp. °K	Ln KF	n		R^2
Fe(II)	293
	303	0.212	1.16		0.960
	313	0.332	1.03		0.969
Cu(II)	293	1.178	1.47		0.974
	303	1.235	1.40		0.981
	313	1.418	1.43		0.979

Experimental condition: volume 50 mL; pH5 for Fe(II) and 6 for Cu(II), [Fe(II), Cu(II)] = 10–400 mgL⁻¹; adsorbent net mass = 0.030 g; temperature = 293, 303, and 313°K; contact time = 2 h, shaking rate = 150 rpm.