The large quantities of heavy metal ions discharged from mines and industries like paints,
pigments, metal fabrication, fertilizers and textiles have become a significant environmental
problem. These ions are a hazard to public health and the environment when discharged
inappropriately [1-2]. Recently low cost biosorbents have received increased attention as they
can significantly reduce the cost of remediation process. Due to the presence in its structure of
amino and hydroxyl groups, which can serve as active sites, CS can be used as a sorbent for the
removal of different polluting agents, dyes or heavy metal ions [3-5]. One way to modulate CS
sorption capacities would consist of obtaining new composites with a synthetic polycation
having reactive primary amine groups.
The purpose of this study was to obtain new composites, based on CS and poly(vinyl
amine) (PVAm), a synthetic polycation less investigated for the composite preparation. The
composites were prepared as beads by an ionic/covalent cross-linking. The sorption capacity of
the composite microspheres for Cu2+, as a function of sorbent dosage, pH, concentration of metal
ion, contact time, and temperature was compared with that of the CS beads cross-linked in the
same conditions. Figure 1 shows a comparison of the sorption capacity of Cu2+ onto CS/PVAm
composite and that of the cross-linked CS as a function of time.

Figure 1. Sorption kinetics of Cu2+ for CS/PVAm compared with cross-linked CS.
As it can be seen from Figure 1 the composite beads presented enhanced the sorption capacity
compared with that of the CS beads.
Acknowledgements: This work was supported by CNCSIS-UEFISCSU by the project PN-IIID-
PCE-2011-3-0300.
References:
[1] Chaterjee, S.; Chaterjee, T.; Woo, S. H. In: Chem. Eng. J. 2011, 166, 168-175.
[2] Laus, R. et al. In: J. Hazard. Mater. 2010, 183, 233-241.
[3] Vasconcelos, H. L. et al. In: React. Funct. Polym. 2008, 68, 572–579.
[4] Dragan, E. S.; Dinu, M. V.; Timpu, D. In: Bioresour. Technol. 2010, 101, 812-817.
[5] Crini, G. In: Bioresour. Technol. 2006, 97, 1061–1085.