Adsorption Evaluation for the Removal of Nickel, Mercury, and Barium Ions from Single-Component and Mixtures of Aqueous Solutions by Using an Optimized Biobased Chitosan Derivative
Efstathios V. Liakos, Mariza Mone, Dimitra A. Lambropoulou, Dimitrios Ν. Bikiaris, George Z. Kyzas
Abstract
In this experimental study, the use of 5-hydroxymethyl-furfural (HMF) organic compound as a grafting agent to chitosan natural polymer (CS) was examined. One optimized chitosan derivative was synthesized, and then tested (CS-HMF), in order to uptake nickel, mercury, and barium metal ions from single- and triple-component (multi-component) aqueous solutions. The characterization of the material before and after the metal uptake was achieved by scanning electron microscopy (SEM). The ability of the adsorption of CS-HMF was tested at pH = 6. The adjusting of temperature from 25 to 65 °C caused the increase in the adsorption capacity. The equilibrium data were fitted to the models of Langmuir and Freundlich, while the data from kinetic experiments were fitted to pseudo-1st and pseudo-2nd order models. The best fitting was achieved for the Langmuir model (higher R2). The adsorption capacity for nickel, mercury, and barium removal at 25 °C (single component) was 147, 107, and 64 (mg/g), respectively. However, the total adsorption capacity for the multi-component was 204 mg/g. A thermodynamic study was also done, and the values of ΔG0, ΔH0, and ΔS0 were evaluated.