Adsorption of Cu(II) and Cr(VI) ions by chitosan: kinetics and equilibrium studies

Abstract

The ability of chitosan as an adsorbent for Cu (II) and Cr (VI) ions in aqueous solution was studied. The experiments were done as batch processes. Equilibrium studies were done on both cross-linked and non-cross-linked chitosan for both metals. Cr (VI) adsorption behaviour could be described using the Langmuir isotherm over the whole concentration range of 10 to 1000 mg·l -1 Cr. The maximum adsorption capacity for both types of chitosan was found to be 78 mg·g -1 for the non-cross-linked chitosan and 50 mg·g -1 for the cross-linked chitosan for the Cr (VI) removal. For the Cu (II) removal the Freundlich isotherm described the experimental data over the whole concentration range of 10 to 1000 mg·l -1 Cu (II). The maximum adsorption capacity for both types of chitosan can be estimated to be greater than 80 mg·g -1 . Cr (VI) removal was the highest at pH 5 but pH did not have a large influence on Cu (II). From these results it is clear that the adsorption of heavy metals is possible with chitosan, but that with this method, end concentrations of below 1 mg·l -1 can hardly be obtained.

Removal of airborne hexavalent chromium mist using chitosan gel beads as a new control approach

“…They reported that, the maximum adsorption of Cr (VI) occurred at pH 5 and decreased at lower and higher pH. Above pH 7 a plateau is observed (Schmuhl et al, 2001). Juang and Ju also in a same study regarding the effect of pH on Cu (II) ions adsorption on chitosan beads (ranged 3-9) reported that, removal efficiency increased first with increasing the pH and then reached a maximum at about pH 5-6, but, it decreased sharply with a further increase in equilibrium pH (Juang and Ju, 1997).…”

“…According to Tobin et al a variation of less than 0.5 units in the pH dose not affect the removal efficiency values (Marroun et al, 1998). Schmuhl et al (2001) studied the effect of the pH (varied between pH 2 and 11) on Cr (VI) sorption using chitosan beads. However, this study has been done on Cr (VI) ion removal from water and there is not similar report in case of polluted air.…”

Polymer Nanocomposites and Cr(VI) Removal from Water

“…Therefore, it is necessary to remove Cr(VI) from wastewater before it is discharged to the natural water bodies. Various treatment technologies such as ion exchange, electrolytic removal, membrane filtration, reverse osmosis, chemical precipitation, adsorption, and solvent extraction have been reported for the removal of Cr(VI) from waste water [25][26][27][28][29][30][31][32][33][34][35][36][37][38]. Most of these technologies are associated with high operational and maintenance cost.…”

Evaluation of Biopolymer-Modified Concrete Systems for Disposal of Cathode Ray Tube Glass

“…From the literature, it is clear that chitosan is a plausible material to remove numerous metals, such as Cu(II), Pb(II), U(VI), Cr(III), Cr(VI), Ni(II), Cd(II), Zn(II), Co(II), Fe(II), Mn(II), Pt(IV), Ir(III), Pd(II), V(V), and V(IV) from heavy metal sources. 16 This kind of metal uptake stems from functional groups like hydroxyl, amino groups, and many hydrogen bonds, which function actively in the inter-and intramolecular structure among adsorbent, adsorbate, and biopolymer.…”