Thien DT, An NT and Hoa NT
In this work, the fully deacetylated chitosan (FCS) was obtained from the deacetylation process of chitosan ( = 31%) in 5% NaOH solution. The structure of FCS was characterized by nuclear magnetic resonance (NMR) spectroscopy, X-Ray diffraction and Bruauer – Emment – Teller (BET) analysis. The FCS was used to adsorb Hg(II) ion from aqueous solutions. The influences of various operating parameters such as pH, temperature, initial concentration of Hg(II) ion and contact time on the adsorption capacity of FCS have been investigated. The results showed that the adsorption capacity of FCS for Hg(II) ion rapidly reached equilibrium within 60 min and strongly depended on pH and temperature. Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. It was shown that the FCS had given good correlation with Langmuir isotherm model and the adsorption kinetics of Hg(II) ion could be best described by the pseudo-second-order model.