Table 3.

Thermodynamic parameters estimated for the adsorption of different metals onto chitin-based adsorbents.

Chitin Adsorbent	Metal	T (K)	ΔG0 (kJ/mol)	ΔΗ0 (kJ/mol)	ΔS0 (kJ/mol K)	Reference
Chitin	Fe3+	293	−4.32	2.16	0.022	[29]
		303	−4.52
		313	−4.72
		323	−4.97
Chemically modified chitin with polypyrrole	Pb2+	303	−3.03	18.92	0.05	[31]
		313	−2.84
		323	−1.98
Chemically modified chitin with polypyrrole	Cd2+	303	−4.61	7.19	0.01	[31]
		313	−4.62
		323	−4.44
Chitin	Cd2+	288	−18.5	10.6	0.101	[32]
		298	−19.5
		308	−20.5
		318	−21.5
Chitin	Cu2+	298	−0.87	−33.65	−0.11	[35]
		308	0.23
		318	1.33
Chitin	Zn2+	293	−18.21	4.13	0.076	[38]
		303	−18.92
		313	−19.73
Chitin from Bargi fish (Heterotis Miloticus)	Cr6+	–	−76.54	−132.59	−0.185	[45]
Polypyrrole-functionalized chitin	Cr6+	303	−8.30	15.51	0.02	[47]
		313	−8.17
		323	−7.82