Table 2.

Comparison of adsorption capacity of FGCX onto Pb, Cu, Ni, Cd, and Zn with other absorbent.

Heavy metal ions	Adsorbent	Q m (mmol/g)	Temperature	Reference
Lead	Mesoporous silicas	2.86	25	[25]
	Romania peat	0.20	20	[26]
	Lignin	0.43	20	[27]
	Cross-linked CMCS resin	1.89	25	[28]
	FGCX	3.96	45	This study
Copper	Mesoporous silicas	2.34	25	[25]
	Cross-linked CMCS resin	1.82	25	[28]
	Lignin	0.36	20	[27]
	FGCX	2.88	45	This study
Nickel	Lignin	0.10	20	[27]
	Cross-linked CMCS resin	0.78	25	[28]
	Alginate microcapsules	0.52		[29]
	FGCX	2.80	45	This study
Cadmium	Mesoporous silicas	1.71	25	[25]
	Romania peat	0.39	20	[26]
	Lignin	0.23	20	[27]
	FGCX	1.82	45	This study
Zinc	Mesoporous silicas	1.36	25	[25]
	Lignin	0.17	20	[27]
	Cross-linked CMCS resin	0.74	25	[28]
	FGCX	1.76	45	This study