Abstract: |
The effect of complex formation on the adsorption behavior of heavy metals is studied by comparing the adsorption characteristics of Co(II) species, (uncomplexed), and [Co(III)EDTA]− complexes on two hydrous solids, namely SiO2 and Al2O3. The results demonstrate that for highly stable metal complexes such as [Co(III)EDTA]−, and particularly ones having three-dimensional structure, their adsorption behavior is influenced by the nature of their ligands. However, their adsorption characteristics do not necessarily copy that of the complex-forming agent. Furthermore, specific chemical interactions with the formation of hydrogen bondings play a very significant role in the adsorption of both the complexed and uncomplexed metal ions on hydrous solids. Adsorption reactions between metal ions, both complexed and uncomplexed, and hydrous solids can be readily described by a surface complex formation model in that the surface hydroxo groups function as the ligands. |