Effect of Complex-Former Ion Concentration on the Selectivity of Metal Ion Sorption on Cross-Linked N-2-Sulfoethylchitosan

Abstract

Copper(II), silver(I), cobalt(II), nickel(II), zinc(II), manganese(II), and magnesium(II) sorption isotherms on cross-linked sulfoethylated chitosan with the degree of sulfoethylation DS = 0.7 (SEC 0.7) have been plotted for the individual or collective presence of these ions in solution have been constructed. The capacities of the studied sorbents for the studied metal ions have been calculated by processing the sorption isotherms. SEC 0.7 is found to have the greatest affinity to copper(II) and silver(I); their presence almost completely suppresses the sorption of associated metal ions. The Redlich–Peterson model gives the best fit to the sorption isotherms for collectively present metal ions, indicating the chemical inhomogeneity of the sorbent surface.