Adsorption of Zinc ions by native and modified acacia bark (<i>Acacia auriculiformis</i>)

Modified sorption materials were produced by treating earleaf acacia ( Acacia auriculiformis ) bark with low-concentration (1-3%wt) sulfuric acid solutions. The properties of native and modified for zinc (II) ions studied. Based on the values initial equilibrium concentrations in solution, materials' capacity (A, mmol/g) was found adsorption isotherms plotted. It that are type I according to IUPAC classification describe process monomolecular adsorption. treatment H2SO4 solutions resulted an increase latter respect due area material extraction part biopolymers matrix into solution. This circumstance leads pore space samples material, which is proved a decrease degree crystallinity. thermodynamic parameters using resulting constants Langmuir Dubinin-Radushkevich models: energy (E, kJ/mol) Gibbs (ΔG, kJ/mol), indicate processes physical processes. kinetics has been studied kinetic dependences Zn2+ have analyzed based Boyd diffusion model it determined all four cases mixed occurred, is, both external internal limiting.