Synthesis and adsorption performance of dithiocarbamate-modified glycidyl methacrylate starch

The design of chelating polymers with fast complexation of the metal ions is particularly interest. In this work, the dithiocarbamate-modified glycidyl methacrylate starch was synthesized and characterized by FT-IR, (13)C NMR and XRD spectra. Its sorption performance for heavy metals fixation was studied. It was found that the removal process of metal ions involved a fast increase stage followed by a slower stage. There was a higher match between the pseudo-second-order equation and the experimental data. The sorption rate constants were related to the substitution rates of hydrated metal ions in aqueous solutions, showing typical chemisorption. The Langmuir isotherm gave satisfying fits to equilibrium data of metals adsorption. And the capacities followed the sequence Cu(2+)>Cd(2+)>Co(2+)>Zn(2+)>Ni(2+)>Mn(2+), which could be well demonstrated with chelating interaction caused by sulfur atoms. Such understanding provides new insights as how to synthesize and use the dithiocarbamate-based polysaccharides.